Molecularly functionalized biomass-derived hydrogels and methods of making and use thereof

Abstract

The disclosed subject matter relates to molecularly functionalized biomass-derived hydrogels and methods of making and use thereof. For example, disclosed herein are molecularly functionalized biomass-derived hydrogel, comprising a polysaccharide derived from a biomass functionalized with a plurality of thermoresponsive alkylations and a plurality of zwitterionic functionalizations. Also disclosed herein are methods of molecularly functionalizing a biomass-derived hydrogel. Also disclosed herein are methods of use of any of the molecularly functionalized biomass-derived hydrogels disclosed herein, such as for atmospheric water harvesting.

Description

[0001] 10046-676W01; 8637 YU MOLECULARLY FUNCTIONALIZED BIOMASS-DERIVED HYDROGELS AND METHODS OF MAKING AND USE THEREOF CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Application No.

[0002] 63 / 760,398 filed February 19, 2025, which is hereby incorporated herein by reference in its entirety.

[0003] BACKGROUND

[0004] Water scarcity is a critical global issue, with billions lacking access to clean drinking water. Traditional water extraction methods, such as groundwater pumping, desalination, and rainwater harvesting, require substantial energy input and infrastructure, making them impractical for decentralized water supply, particularly in arid and remote regions. Atmospheric water harvesting (AWH) offers an alternative solution, but existing technologies face significant limitations in efficiency, operability, and sustainability.

[0005] Currently, synthetic polymer-based sorbents such as hydrogels are being developed to capture water from air. While these materials exhibit high water uptake, they often suffer from energy -intensive regeneration, limited long-term stability, and reliance on petroleum-based feedstocks, raising concerns about environmental impact and scalability. Additionally, traditional strategies for utilizing biomass in materials science have been material-specific and tailored, following a select-and-combine approach, where individual biomass components are selectively modified to serve as adsorbents. However, such approaches lack generalizability and often require complex processing steps to optimize adsorption and desorption properties.

[0006] There is a pressing need for a generalizable and scalable strategy to transform abundant biomass resources into high-performance, energy-efficient water sorbents, overcoming the limitations of both synthetic polymer-based sorbents and traditional biomass utilization methods. The compositions, devices, and methods discussed herein address these and other needs.

[0007] SUMMARY

[0008] In accordance with the purposes of the disclosed compositions, methods, and systems as embodied and broadly described herein, the disclosed subject matter relates to molecularly functionalized biomass-derived hydrogels and methods of making and use thereof.

[0009] For example, disclosed herein are molecularly functionalized biomass-derived hydrogels, comprising a polysaccharide derived from a biomass functionalized with a plurality of thermoresponsive alkylations and a plurality of zwitterionic functionalizations.

[0010] In some examples, the polysaccharide is derived from a sustainable biomass feedstock. In some examples, the polysaccharide comprises a carbohydrate.10046-676W01; 8637 YU In some examples, wherein the polysaccharide comprises a native carbohydrate, a modified carbohydrate, a derivative of a carbohydrate, a breakdown product (e.g., metabolite) of a carbohydrate, or a combination thereof.

[0011] In some examples, the polysaccharide comprises cellulose, hemicelluloses, starch, pectins, chitin, chitosan, gums / galactomannans, alginates / agar / carrageenans; derivatives thereof; mixtures thereof; and / or breakdown products (e.g., metabolites) thereof.

[0012] In some examples, the polysaccharide comprises cellulose, starch, chitosan, or a combination thereof.

[0013] In some examples, the polysaccharide comprises cellulose.

[0014] In some examples, the polysaccharide comprises starch.

[0015] In some examples, the polysaccharide comprises chitosan.

[0016] In some examples, the plurality of thermoresponsive alkylations disrupt the hydrogen bond network of the polysaccharide to facilitate further modifications, and balance hydrophobic and hydrophilic elements to confer thermoresponsiveness, enabling the hydrophobic interaction at elevated temperatures to ease the release of water molecules.

[0017] In some examples, the plurality of thermoresponsive alkylations comprise N-alkyl amide motifs (for example, N-isopropyl, N-ethyl, N-propyl, N-cyclopropyl, and N, N-dialkyl amide functionalities), cyclic amide (lactam) motifs (for example, pyrrolidone and caprolactam functionalities), oligo(ethylene glycol) motifs (for example, pendant OEG chains of tunable ethylene-oxide length and end group), hydroxy alkyl motifs (for example, hydroxypropyl and hydroxybutyl functionalities), tertiary amine motifs (for example, dialkylaminoalkyl functionalities), or a combination thereof.

[0018] In some examples, the plurality of thermoresponsive alkylations comprise hydroxypropyl groups, hydroxybutyl groups, or a combination thereof.

[0019] In some examples, the polysaccharide comprises cellulose and the plurality of thermoresponsive alkylations comprise hydroxypropyl groups.

[0020] In some examples, the polysaccharide comprises starch and the plurality of thermoresponsive alkylations comprise hydroxybutyl groups.

[0021] In some examples, the polysaccharide comprises chitosan and the plurality of thermoresponsive alkylations comprise hydroxybutyl groups.

[0022] In some examples, the plurality of zwitterionic functionalizations are derived from a zwitterionic agent comprising sulfobetaines (quaternary ammonium paired with sulfonate), carboxybetaines (quaternary ammonium paired with carboxylate), phosphobetaines / phosphorylcholine-like groups (quaternary ammonium or phosphonium paired10046-676W01; 8637 YU with phosphate, phosphonate, or related oxyanions), or a combination thereof.

[0023] In some examples, the plurality of zwitterionic functionalizations are derived from a zwitterionic agent comprising (3-((3-chloropropyl)dimethylammonio)propane-l-sulfonate).

[0024] In some examples, the molecularly functionalized biomass-derived hydrogel further comprises a salt.

[0025] In some examples, the salt comprises a hydroscopic salt.

[0026] In some examples, the salt comprises a lithium salt, a calcium salt, a magnesium salt, a zinc salt, an aluminum salt, an iron salt, a copper salt, a sodium salt, a potassium salt, an ammonium salt, or a combination thereof.

[0027] In some examples, the salt comprises a chloride salt, a bromide salt, an iodide salt, a hydroxide salt, a carbonate salt, an acetate salt, a perchlorate salt, a sulfate salt, a nitrate salt, or a combination thereof.

[0028] In some examples, the salt comprises Lithium chloride (Lid), lithium bromide (LiBr), lithium iodide (Lil), calcium chloride (CaCb), calcium bromide (Caffe), magnesium chloride (MgCb), magnesium bromide (MgEfe), zinc chloride (ZnCb), aluminum chloride (AlCh, typically as hydrates / complexes), ferric chloride (FeCL), copper (II) chloride (CuCL), sodium hydroxide (NaOH), potassium hydroxide (KOH), potassium carbonate (K2CO3), sodium carbonate (Na^COrs), potassium acetate (KOAc), sodium acetate (NaOAc), magnesium perchlorate (Mg(CIO )z), calcium perchlorate (Ca(C104)?.), sodium perchlorate (NaOCL), potassium perchlorate (KCIO4), sodium sulfate (Na2SO4, notably as hydrates), magnesium sulfate (MgSO4, notably as hydrates), calcium nitrate (Ca(NOj)2), magnesium nitrate (Mg(NOs)2), zinc nitrate (ZnlNOs)?.), ammonium nitrate (NILNOs), ammonium chloride (NILC1), and ammonium sulfate ((NILbSCh).

[0029] In some examples, the salt comprises a lithium salt, a calcium salt, or a combination thereof. In some examples, the salt comprises LiCl, CaCl2, or a combination thereof.

[0030] In some examples, the molecularly functionalized biomass-derived hydrogel is crosslinked.

[0031] In some examples, the molecularly functionalized biomass-derived hydrogel is further derived from one or more crosslinking monomers.

[0032] In some examples, the molecularly functionalized biomass-derived hydrogel has a lower critical solution temperature of from 10 to 80°C, such as from 30 to 60°C.

[0033] In some examples, the molecularly functionalized biomass-derived hydrogel exhibits enhanced water uptake under a range of relative humidity (RH) conditions (e.g., 5%-100%, such as from 15-60%), stabilizes hygroscopic salts, enables energy-efficient water release at moderate10046-676W01: 8637 YU temperatures (~50-60°C), or a combination thereof.

[0034] In some examples, the molecularly functionalized biomass-derived hydrogel demonstrates high sorption-desorption cycling stability.

[0035] In some examples, the molecularly functionalized biomass-derived hydrogel shows a water uptake of from 0.1 to 10 grams of water per gram of hydrogel, such as from 0.86-1.32 g g-1, at 15-30% relative humidity (RII).

[0036] In some examples, the molecularly functionalized biomass-derived hydrogel has a water collection rate of from 1 to 50 kg kg-1day-1in outdoor conditions, such as 14 kg kg-1day-1or more.

[0037] Also disclosed herein are interpenetrating networks derived from any of the molecularly functionalized biomass-derived hydrogels disclosed herein.

[0038] Also disclosed herein are methods of making any of the molecularly functionalized biomass-derived hydrogels disclosed herein.

[0039] Also disclosed herein are methods of molecularly functionalizing a biomass-derived hydrogel, the methods comprising: performing alkylation of a polysaccharide derived from a biomass to thereby functionalize the polysaccharide with a plurality of thermoresponsive alkylations; and integrating zwitterionic groups into the polysaccharide to thereby functionalize the polysaccharide with a plurality of zwitterionic functionalizations.

[0040] In some examples, the zwitterionic functionalization is performed after the alkylation. In some examples, the zwitterionic functionalization comprises a plurality of zwitterionic functionalization steps.

[0041] In some examples, the alkylation is via an epoxide ring-opening reaction.

[0042] In some examples, the zwitterionization is via Williamson etherification.

[0043] In some examples, the method further comprises extracting the polysaccharide from the biomass.

[0044] In some examples, the molecularly functionalized biomass-derived hydrogel made by any of the methods disclosed herein comprises any of the molecularly functionalized biomass- derived hydrogels disclosed herein.

[0045] In some examples, the method is a cost-effective large-scale synthesis, for example via supercritical CO₂ processing and / or continuous flow chemistry.

[0046] Also disclosed herein are methods of use of any of the molecularly functionalized biomass-derived hydrogels disclosed herein and / or any of the interpenetrating networks disclosed herein. In some examples, the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network for atmospheric water harvesting.10046-676W01; 8637 YU In some examples, the method comprises passive or solar-assisted water recovery. In some examples, the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network for humidity control in an enclosed space. In some examples, the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network in a thermal management or passive cooling application. In some examples, the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network in pharmaceutical and / or food packaging. In some examples, the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network in water collection, water purification, water management, or a combination thereof. In some examples, the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network in water capture, water logistics, process water, humidity control, humidity preservation, humidity packaging, building materials, HVAC integration, thermal management, cooling, gas drying, industrial separations, corrosion control, materials protection, or a combination thereof.

[0047] Also disclosed herein are articles of manufacture comprising any of the molecularly functionalized biomass-derived hydrogels disclosed herein and / or any of the interpenetrating networks disclosed herein. In some examples, the article comprises an atmospheric water harvesting device, e.g., an indoor and / or outdoor atmospheric water harvesting device. In some examples, the article comprises a portable water harvester, a self-sustaining irrigation system, an emergency drinking water device, or a combination thereof.

[0048] Additional advantages of the disclosed compositions, systems, and methods will be set forth in part in the description which follows, and in part will be obvious from the description. The advantages of the disclosed compositions, systems, and methods will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed compositions, systems, and methods, as claimed.

[0049] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

[0050] BRIEF DESCRIPTION OF THE FIGURES

[0051] The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate several aspects of the disclosure, and together with the description, serve to explain the principles of the disclosure.10046-676W01; 8637 YU Figure 1. Molecularly functionalized biomass hydrogels for sustainable atmospheric water harvesting. A generalizable molecular engineering methodology is developed to transform diverse biomass feedstocks, such as cellulose, starch, and chitosan, into efficient hydrogel sorbents for atmospheric water harvesting (AWH). Outdoor tests reveal a water production rate of up to 14.19 kg kg * day-1, demonstrating significant potential for sustainable water solutions. This approach advances scalable atmospheric water harvesting technologies by leveraging abundant, environmentally friendly resources.

[0052] Figure 2. Molecular functionalization strategy of natural polysaccharides as hydrogel sorbents. Molecular functionalization of natural polysaccharides, derived from abundant biomass, enhances their water uptake and lowers the desorption temperature, activating them as sorption-based atmospheric water harvesting sorbents. At room temperature, the hydrogel absorbs moisture and swells, representing the water sorption state (blue swollen hydrogel, upper right). Upon heating, hydrophobic interactions among the thermoresponsive groups dominate, causing the hydrogel network to contract and transition to the water release state (red contracted hydrogel, bottom right).

[0053] Figure 3a-Figure 3f. Synthesis and properties of zwitterionic hydroxypropyl cellulose. (Figure 3a) Schematic representation of the synthetic route for molecularly functionalized cellulose in atmospheric water harvesting application. The chemical structure depicted is for illustrative purposes only. (Figure 3b)1H NMR spectra illustrating hydroxypropyl cellulose, ZHPC-1, ZHPC-2, and ZHPC-3, along with the chemical structure of zwitterionic hydroxypropyl cellulose. (Figure 3c) FTIR spectra comparison of pristine cellulose, hydroxypropyl cellulose, ZHPC-3, and the zwitterionic agent (3-((3- chloropropyl)dimethylammonio)propane-l -sulfonate). (Figure 3d) XRD patterns for pristine cellulose and ZHPC-3 hydrogel. (Figure 3e) Swelling ratios of cellulose hydrogel and ZHPC-3 hydrogel in varied LiCl concentration solutions. (Figure 3f) Heat flow profiles from DSC test, showcasing the phase transition behavior of hydroxypropyl cellulose, ZHPC-1, ZHPC-2, and ZHPC-3.

[0054] Figure 4a-Figure 4h. atmospheric water harvesting performance of zwitterionic hydroxypropyl cellulose hydrogel sorbents. (Figure 4a) Static water vapor sorption-desorption curves for ZHPC-1, ZHPC-2, and ZHPC-3 / LiCl hydrogel sorbents at 30% relative humidity and 25 °C. Desorption conditions: 60 °C, 15% relative humidity. (Figure 4b) Static water vapor sorption-desorption curves of ZHPC-3 / LiCl hydrogel sorbents at 15%, 30%, and 60% relative humidity at 25 °C. Desorption conditions: 60 °C, 15% relative humidity. (Figure 4c) Heat flow profiles detailing the evaporation behavior of cellulose hydrogel and ZHPC-3 / LiCl hydrogel.10046-676W01; 8637 YU (Figure 4d) Static desorption curves of ZHPC-3 / LiCl hydrogel under various temperatures with a consistent water vapor pressure of 3.17 kPa. (Figure 4e) Cycling performance of ZHPC-3 / LiCl hydrogel over an extended period with repeated sorption-desorption cycles; sorption at 30% relative humidity and desorption at 60 °C. (Figure 4f) Static water vapor sorption-desorption curves of ZHPC-3 / LiCl hydrogel pre- and post-cycling. (Figure 4g) Water uptake and water collection at varying relative humidity levels. (Figure 4h) Cycling test for water collection using ZHPC-3 / LiCl hydrogel at 30% relative humidity.

[0055] Figure 5a-Figure 5j. Material properties and atmospheric water harvesting performance of zwitterionized hydroxybutyl-modified starch and zwitterionic hydroxybutyl-modified chitosan hydrogel sorbents. (Figure 5a- Figure 5e) depict the starch system (ZHBS) and (Figure 5f- Figure 5j) depict the chitosan system (ZHBC), with mirrored analyses. (Figure 5a, Figure 5f)JH NMR spectra show HBS / HBC, ZHBS / ZHBC-1, and ZHBS / ZHBC-2, including their chemical structures. (Figure 5b, Figure 5g) XRD patterns compare pristine substrates with ZHBS / ZHBC-1, illustrating structural transitions. (Figure 5c, Figure 5h) DSC heat flow profiles reveal phase transition behaviors across HBS / HBC, ZHBS / ZHBC-1, and ZHBS / ZHBC-2. (Figure 5d, Figure 5i) Static water vapor sorption-desorption curves at 15%, 30%, and 60% relative humidity at 25 °C, with desorption at 60 °C, 15% relative humidity, for ZHBS / ZHBC-1 LiCl hydrogels.

[0056] (Figure 5e, Figure 5j) Cycling performance over extended periods, with sorption at 30% relative humidity and desorption at 60 °C, for ZHBS / ZHBC-1 LiCl hydrogels.

[0057] Figure 6a-Figure 6f. Outdoor atmospheric water harvesting test. (Figure 6a) Display of a series of bottles containing large-volume 2 wt% zwitterionic hydroxypropyl cellulose solution, illustrating the scalability of the synthesis process. (Figure 6b) Water collection device setup. Scale bar: 10 cm. The inset at the top right shows the zwitterionic hydroxypropyl cellulose hydrogel sorbent, with a diameter of -15 cm and a thickness of -2 cm. The bottom right inset shows water droplets condensed on the device's cover. (Figure 6c) Displays the water content from sorption / desorption processes and the accumulated water collected from condensation at the top, with outdoor temperature and relative humidity data shown at the bottom. The light blue and red regions indicate the sorption and desorption phases, respectively. These measurements were taken on March 1st–6th, 2024, in Austin, Texas, USA. (Figure 6d) The photograph of the collected water. (Figure 6e) ICP-MS analysis detailing cation residues in the collected water. Lithium lacks a guideline level in drinking water. An estimated threshold of 0.70 mg / L is based on the EPA's oral reference dose of 20 pg / kg / day

[0044] , (Figure 6f) Comparative analysis of different materials based on key intrinsic properties essential for practical atmospheric water harvesting applications.10046-676W01; 8637 YU Figure 7. Main reaction equation of the hydroxypropylation of cellulose.

[0058] Figure 8. Schematic illustration of the phase transition mechanism of hydroxypropyl cellulose.

[0059] Figure 9a-Figure 9b. NMR results of hydroxypropyl cellulose with different hydroxypropyl substitution level. (Figure 9a)

[0060]

[0061] NMR spectra of HPCs with 25 mol / anhydroglucose unit, 15mol / anhydroglucose unit, and 40 mol / anhydroglucose unit propylene oxide treatment. (Figure 9b)13C NMR spectrum of hydroxypropyl cellulose with 15 mol / anhydroglucose unit treatment.

[0062] Figure 10. Reaction equation of the synthesis of zwitterionic agent.

[0063] Figure 11.lH NMR spectrum of zwitterionic agent 3-((3-chloropropyi)dimethylarnmonio)propane-l -sulfonate.

[0064] Figure 12a-Figure 12b. Reaction equations of the zwitterionization of cellulose. (Figure 12a) Main reaction. (Figure 12b) Side reaction.

[0065] Figure 13.JH NMR spectra of Zwitterionic hydroxypropyl celluloses.

[0066] Figure 14. Swelling ratios of Zwitterionic hydroxypropyl celluloses in LiCl solution. Figure 15. Optical images of hydroxypropyl cellulose and Zwitterionic hydroxypropyl celluloses before and after phase transition. The polymer solutions undergo phase transition after heating to their corresponding lower critical solution temperature. Scale bar: 1 cm.

[0067] Figure 16. Optical images of the as-synthesized hydrogel before and after phase transition.

[0068] Figure 17. Cross-section SEM images (left) and EDX mapping (right) of zwitterionic hydroxypropyl cellulose hydrogel. Scale bar: 200 pm (left) and 50 pm (right).

[0069] Figure 18. thermogravimetric analysis curves of cellulose / LiCl hydrogel.

[0070] Figure 19. thermogravi metric analysis curves of zwitterionic hydroxypropyl cellulose / LiCl hydrogels.

[0071] Figure 20. dynamic vapor sorption water vapor sorption curve of pristine cellulose at 15, 30, 60% relative humidity.

[0072] Figure 21. dynamic vapor sorption water vapor sorption curve of cellulose / LiCl hydrogel at 15, 30, 60% relative humidity.

[0073] Figure 22a-Figure 22b. Atmospheric water harvesting properties of hydroxypropyl cellulose / LiCl hydrogel. (Figure 22a) dynamic vapor sorption results of the hydrogel at 30% and 60% relative humidity. (Figure 22b) Themogravimetric analysis results of the hydrogel.

[0074] Figure 23. Sorption isotherm of zwitterionic hydroxypropyl cellulose hydrogel.

[0075] Figure 24a-Figure 24b. Optical images of zwitterionic hydroxypropyl cellulose hydrogel10046-676W01; 8637 YU on paper. (Figure 24a) Swollen gel after sorption and (Figure 24b) the wipe underneath. Scale bar: 2cm.

[0076] Figure 25a-Figure 25b. Water uptake of zwitterionic hydroxypropyl cellulose / CaCh hydrogel. (Figure 25a) Static vapor sorption test of zwitterionic hydroxypropyl cellulose / CaCh hydrogel. (Figure 25b) Themogravimetric analysis results of the hydrogel.

[0077] Figure 26a-Figure 26b. Desorption curves of zwitterionic hydroxypropyl cellulose hydrogels. Comparisons of desorption performance of zwitterionic hydroxypropyl cellulose hydrogels at (Figure 26a) 50 °C and (Figure 26b) 60 °C.

[0078] Figure 27. Indoor water collection system. Scale bar: 1 cm.

[0079] Figure 28A-Figure 28b. Water vapor sorption measurement setup. (Figure 28a) Schematic and (Figure 28b) photograph of the homemade water vapor sorption system.

[0080] Figure 29.

[0081]

[0082] NMR spectra of hydroxybutyl-modified starches.

[0083] Figure 30. Heat flow profiles of hydroxybutyl-modified starches with different hydroxybutyl substitutions.

[0084] Figure 31.1H NMR spectra of zwitterionized hydroxybutyl-modified starches.

[0085] Figure 32. Cross-section SEM images (left) and EDX mapping (right) of zwitterionized hydroxybutyl-modified starch hydrogel. Scale bar: 200 pm (left) and 50 pm (right).

[0086] Figure 33. dynamic vapor sorption water vapor sorption curve of pristine starch at 15, 30, 60% relative humidity.

[0087] Figure 34. Desorption curves of ZHBS-1 / LiCl hydrogels. Static desorption curves of ZHBS-1 / LiCl hydrogel under various temperatures with a consistent water vapor pressure of 3.17 kPa.

[0088] Figure 35. dynamic vapor sorption curves of ZHBS-1 / LiCl hydrogels before and after cycling.

[0089] Figure 36.

[0090]

[0091] NMR spectra of zwitterionic hydroxybutyl-modified chitosans.

[0092] Figure 37. Heat flow profiles of hydroxybutyl-modified chitosans with different hydroxybutyl substitutions.

[0093] Figure 38. Cross-section SEM images (left) and EDX mapping (right) of zwitterionic hydroxybutyl-modified chitosan hydrogel. Scale bar: 200 pm (left) and 50 pm (right).

[0094] Figure 39. dynamic vapor sorption water vapor sorption curve of pristine chitosan at 15, 30, 60% relative humidity.

[0095] Figure 40. Desorption curves of ZHBC-l / LiCl hydrogels. Static desorption curves of ZHBC-1 / LiCl hydrogel under various temperatures with a consistent water vapor pressure of 3.17 kPa.10046-676W01; 8637 YU Figure 41. dynamic vapor sorption curves of ZHBC-1 / LiCl hydrogels before and after cycling.

[0096] Figure 42a-Figure 42b. Comparison of atmospheric water harvesting properties between IPN and single network hydrogels for the starch system. (Figure 42a) Water uptake comparison at 30% relative humidity and (Figure 42b) desorption performance comparison.

[0097] Figure 43a-Figure 43b. Comparison of atmospheric water harvesting properties between IPN and single network hydrogels for the chitosan system. (Figure 43a) Water uptake comparison and (Figure 43b) desorption performance comparison.

[0098] Figure 44.1H NMR spectra of ZHPC-3 synthesized in large and small batches.

[0099] Figure 45. Water uptake comparison between small and large gels.

[0100] Figure 46. The relationship between the water price and the system lifetime.

[0101] Figure 47a-Figure 47b. Cross-section SEM images of gel thin film. Scale bar: 500 pm (Figure 47a) and 100 pm (Figure 47b).

[0102] Figure 48a-Figure 48b. Outdoor Water Harvesting with Gel Thin Film. (Figure 48a) Illustrates the arrangement of gel films within the water collection chamber. Each gel film has a thickness of ~0.5 mm and a diameter of -15 cm. (Figure 48b) Presents water yield from the sorption / desorption cycles and the total water collected through at the top, alongside the condensation outdoor temperature and relative humidity data at the bottom. These selected data were recorded on March 9- 10th, 2024, in Austin, Texas, USA. It is important to note that the study concluded at 8:00 am, accounting for the transition to daylight saving time at 3:00 am (previously 2:00 am) on March 11t.

[0103] Figure 49a-Figure 49b. Outdoor Water Har vesting with Gel Thin Film. (Figure 49a) Zwitterionized hydroxybutyl-modified starch measured from 9 / 287:00 to 9 / 29 7:00, and (Figure 49b) zwitterionic hydroxybutyl-modified chitosan measured from 9 / 29 7:00 to 9 / 307:00.

[0104] Figure 50a-Figure 50b. All-day 30% relative humidity water harvesting performance. (Figure 50a) Dual-cyclic operation using bulk hydrogel, and (Figure 50b) multi-cyclic operation using hydrogel films.

[0105] Figure 51a-Figure 51c. Photothermal properties and water absorption of photothermal zwitterionic hydroxypropyl cellulose sorbents. (Figure 51a) Solar spectrum absorbance of the sorbents. (Figure 51b) Comparison of water uptake between zwitterionic hydroxypropyl cellulose and photothermal zwitterionic hydroxypropyl cellulose sorbents. (Figure 51c) Infrared images of photothermal zwitterionic hydroxypropyl cellulose sorbents under varying sunlight intensities.

[0106] Figure 52a-Figure 52b. Impact of solvent recycling on zwitterionic agent synthesis.10046-676W01; 8637 YU (Figure 52a) Product yield after five recycling cycles. (Figure 52b)1H NMR spectra of the product from each cycle.

[0107] Figure 53. Schematic illustration of sorption-based atmospheric water harvesting.

[0108] Figure 54. Schematic illustration of hydrogel sorbents.

[0109] Figure 55. Hydrogel sorbents: towards material sustainability.

[0110] Figure 56. Biomass feedstocks and biomass polymers.

[0111] Figure 57. Polysaccharides represent a promising sorbent platform with extensive functionalization opportunities.

[0112] Figure 58. Enhancing desorption efficiency: thermoresponsive biomass.

[0113] Figure 59. Enhancing water update: zwitterionic biomass.

[0114] Figure 60. Design rationale of molecularly functionalized biomass hydrogels (MFBHs). Figure 61. Synthesis process of molecularly functionalized cellulose.

[0115] Figure 62a-Figure 62c. Characterizations of molecularly functionalized cellulose. (Figure 62a)1H-NMR analysis; (Figure 62b) swelling behavior; (Figure 62c) XRD patterns.

[0116] Figure 63a-Figure 63b. Water uptake of cellulose system. (Figure 63a) Water uptake of cellulose with different levels of zwitterionization. (Figure 63b) Water uptake at different RH levels.

[0117] Figure 64a-Figure 64c. Water release behavior of cellulose system. (Figure 64a) Water desorption curves at various temperatures. (Figure 64b) Phase transition temperatures of cellulose with different levels of zwitterionization. (Figure 64c) Evaporation profiles of cellulose and molecular functionalized cellulose hydrogels.

[0118] Figure 65a-Figure 65b.1H-NMR analysis of molecularly functionalized (Figure 65a) starch and (Figure 65b) chitosan.

[0119] Figure 66a-Figure 66b. Water update of molecularly functionalized (Figure 66a) starch and (Figure 66b) chitosan.

[0120] Figure 67a-Figure 67d. Desorption curves of (Figure 67a) starch and (Figure 67c) chitosan systems. Phase transition temperatures of (Figure 67b) starch and (Figure 67d) chitosan systems.

[0121] Figure 68a-Figure 68e. Outdoor atmospheric water harvesting test. (Figure 68a) Display- of a series of bottles containing large-volume 2 wt% ZHPC solution (Figure 68 b) Water collection device setup. Scale bar: 10 cm. The inset at the top right shows the ZHPC hydrogel sorbent, with a diameter of ~15 cm and a thickness of ~2 cm. The bottom right inset shows waterdroplets condensed on the device's cover. (Figure 68c) Displays the water content from sorption / desorption processes and the accumulated water collected from condensation at the top,10046-676W01; 8637 YU with outdoor temperature and RH data shown at the bottom (Figure 68d) The photograph of the collected water. (Figure 68e) ICP-MS analysis detailing cation residues in the collected water.

[0122] Figure 69a-Figure 69b. Outdoor atmospheric water harvesting test with gel thin film. (Figure 69a) Illustrates the arrangement of gel films within the water collection chamber. Each gel film has a thickness of ~0.5 mm and a diameter of ~1 cm. (Figure 69b) Presents water yield from the sorption / desorption cycles and the total water collected through at the top, alongside the condensation outdoor temperature and RH data at the bottom.

[0123] DETAILED DESCRIPTION

[0124] Before the present compositions, methods, and systems are disclosed and described, it is to be understood that the aspects described below are not limited to specific synthetic methods or specific reagents, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.

[0125] Also, throughout this specification, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which the disclosed matter pertains. The references disclosed are also individually and specifically incorporated by reference herein for the material contained in them that is discussed in the sentence in which the reference is relied upon.

[0126] General Definitions

[0127] In this specification and in the claims that follow, reference will be made to a number of terms, which shall be defined to have the following meanings.

[0128] Throughout the description and claims of tills specification the word “comprise” and other forms of the word, such as “comprising” and “comprises,” means including but not limited to, and is not intended to exclude, for example, other additives, components, integers, or steps. As used in the specification and in the claims, the term “comprising” can include the aspects “consisting of” and “consisting essentially of.”

[0129] As used in the description and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a composition” includes mixtures of two or more such compositions, reference, to “an agent” includes mixtures of two or more such agents, reference to “the component” includes mixtures of two or more such components, and the like.

[0130] “Optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where the event or circumstance10046-676W01; 8637 YU occurs and instances where it does not.

[0131] Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. By “about” is meant within 5% of the value, e.g., within 4, 3, 2, or 1% of the value. When such a range is expressed, another aspect includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0132] Throughout this disclosure, various aspects of the invention can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of die invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, a description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, 6 and any whole and partial increments therebetween. This applies regardless of the breadth of the range.

[0133] When the specific values are disclosed between two end values, it is understood that these end values can also be included.

[0134] For the terms “for example” and “such as,” and grammatical equivalences thereof, the phrase “and without limitation” is understood to follow unless explicitly stated otherwise. It is further understood that these phrases are not used in a restrictive sense, but for explanatory- purposes. “Exemplary” means “an example of” and is not intended to convey an indication of a preferred or ideal embodiment.

[0135] Values can be expressed herein as an “average” value. “Average” generally refers to the statistical mean value.

[0136] It is understood that throughout this specification the identifiers “first” and “second” are used solely to aid in distinguishing the various components and steps of the disclosed subject matter. The identifiers “first” and “second” are not intended to imply any particular order, amount, preference, or importance to the components or steps modified by these terms.

[0137] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0138] As used herein, the term "substantially" means that the subsequently described event or circumstance completely occurs or that the subsequently described event or circumstance10046-676W01; 8637 YU generally, typically, or approximately occurs.

[0139] Still further, the term “substantially” can, in some aspects, mean within 5%, e.g., within 4%, 3%, 2%, or 1%.

[0140] In other aspects, as used herein, the term “substantially free,” when used in the context of a composition or component of a composition that is substantially absent, is intended to refer to an amount that is then about 1 % by weight, e.g., less than about 0.5 % by weight, less than about 0.1 % by weight, less than about 0.05 % by weight, or less than about 0.01 % by weight of the stated material, based on the total weight of the composition.

[0141] The expressions “ambient temperature” and “room temperature” as used herein are understood in the art and refer generally to a temperature from about 20°C to about 35°C.

[0142] References in the specification and concluding claims to parts by weight of a particular element or component in a composition denotes the weight relationship between the element or component and any other elements or components in the composition or article for which a part by weight is expressed. Thus, in a mixture containing 2 parts by weight of component X and 5 parts by weight of component Y, components X and Y are present at a weight ratio of 2:5 and are present in such a ratio regardless of whether additional components are contained in the mixture.

[0143] A weight percent (wt.%) of a component, unless specifically stated to the contrary, is based on the total weight of the formulation or composition in which the component is included.

[0144] A volume percent (vol%) of a component, unless specifically stated to the contrary, is based on the total volume of the formulation or composition in which the component is included.

[0145] The term “or combinations thereof’ as used herein refers to all permutations and combinations of the listed items preceding the term. For example, “A, B, C, or combinations thereof’ is intended to include at least one of: A, B, C, AB, AC, BC, or ABC, and if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB.

[0146] Continuing with this example, expressly included are combinations that contain repeats of one or more item or term, such as BB, AAA, AB, BBC, AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context.

[0147] As used herein, “molecular weight” refers to number average molecular' weight as measured by ’H NMR spectroscopy, unless indicated otherwise.

[0148] As used herein, a “fluid” includes a liquid, a gas, a supercritical fluid, or a combination thereof.

[0149] As used herein the term “plurality” means 2 or more (e.g., 3 or more; 4 or more; 5 or more; 10 or more; 15 or more; 20 or more; 25 or more; 30 or more; 40 or more; 50 or more; 7510046-676W01; 8637 YU or more; 100 or more; 150 or more; 200 or more; 250 or more; 300 or more; 400 or more; 500 or more; 750 or more; 1000 or more; 1500 or more; 2000 or more; 2500 or more; 3000 or more; 4000 or more; or 5000 or more).

[0150] Chemical Definitions

[0151] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0152] The organic moieties mentioned when defining variable positions within the general formulae described herein (e.g., the term “halogen”) are collective terms for the individual substituents encompassed by the organic moiety.

[0153] The prefix Cn-Cmpreceding a group or moiety indicates, in each case, the possible number of carbon atoms in the group or moiety that follows. For example, the term " Cn-Cra" (or “Cn-m”) employed alone or in combination with other terms refers to a hydrocarbon group that may be straight-chain or branched, having n to m carbons. It is understood that the terms Cn-mand Cn-Cmcan be used interchangeably and just to show that the specific compound has between n to m carbons.

[0154] The term “ion,” as used herein, refers to any molecule, portion of a molecule, cluster of molecules, molecular complex, moiety, or atom that contains a charge (positive, negative, or both at the same time within one molecule, cluster of molecules, molecular complex, or moiety (e.g., zwitterions)) or that can be made to contain a charge. Methods for producing a charge in a molecule, portion of a molecule, cluster of molecules, molecular complex, moiety, or atom are disclosed herein and can be accomplished by methods known in the art, e.g., protonation, deprotonation, oxidation, reduction, alkylation, acetylation, esterification, de-esterification, hydrolysis, etc.

[0155] The term “anion” is a type of ion and is included within the meaning of the term “ion.” An “anion” is any molecule, portion of a molecule (e.g., zwitterion), cluster of molecules, molecular complex, moiety, or atom that contains a net negative charge or that can be made to contain a net negative charge. The term “anion precursor” is used herein to specifically refer to a molecule that can be converted to an anion via a chemical reaction (e.g., deprotonation).

[0156] The term “cation” is a type of ion and is included within the meaning of the term “ion.” A “cation” is any molecule, portion of a molecule (e.g., zwitterion), cluster of molecules, molecular complex, moiety, or atom, that contains a net positive charge or that can be made to contain a net positive charge. The term “cation precursor” is used herein to specifically refer to a molecule that can be converted to a cation via a chemical reaction (e.g., protonation or10046-676W01: 8637 YU alkylation).

[0157] " Zwiterionic" or "zwiterion" as used herein refers to a neutral molecule with a positive (or cationic) and a negative (or anionic) electrical charge at different locations within the same molecule.

[0158] As used herein, the term “substituted” means that a hydrogen atom is removed and replaced by a substituent. It is contemplated to include all permissible substituents of organic compounds. As used herein, the phrase "optionally substituted" means unsubstituted or substituted. It is to be understood that substitution at a given atom is limited by valency. In a broad aspect, the permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, and aromatic and nonaromatic substituents of organic compounds. Illustrative substituents include, for example, those described below. The permissible substituents can be one or more and the same or different for appropriate organic compounds. For purposes of tills disclosure, the heteroatoms, such as nitrogen, can have hydrogen substituents and / or any permissible substituents of organic compounds described herein which satisfy the valencies of the heteroatoms. This disclosure is not intended to be limited in any manner by the permissible substituents of organic compounds. Also, the terms “substitution” or “substituted with” include the implicit proviso that such substitution is in accordance with permitted valence of the substituted atom and the substituent, and that the substitution results in a stable compound, e.g., a compound that does not spontaneously undergo transformation such as by rearrangement, cyclization, elimination, etc. In still further aspects, it is understood that when the disclosure describes a group being substituted, it means that the group is substituted with one or more (i.e., 1, 2, 3, 4, or 5) groups as allowed by valence selected from alkyl, halogenated alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester, ether, halide, hydroxy, ketone, nitro, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, or thiol, as described below.

[0159] The term "compound," as used herein, is meant to include all stereoisomers, geometric isomers, tautomers, and isotopes of the structures depicted. Compounds herein identified by name or structure as one particular tautomeric form are intended to include other tautomeric forms unless otherwise specified.

[0160] Compounds provided herein can also include tautomeric forms. Tautomeric forms result from the swapping of a single bond with an adjacent double bond together with the concomitant migration of a proton. Tautomeric forms include prototropic tautomers, which are isomeric protonation states having the same empirical formula and total charge. Example prototropic tautomers include ketone - enol pairs, amide - imidic acid pairs, lactam - lactim pairs, enamine -10046-676W01; 8637 YU imine pairs, and annular forms where a proton can occupy two or more positions of a heterocyclic system, for example, HI- and 3H-imidazole, 1H-, 2H- and 4H-l,2,4-triazole, 1H- and 2H- isoindole, and 1H- and 2H-pyrazole. Tautomeric forms can be in equilibrium or stericaily locked into one form by appropriate substitution.

[0161] Compounds provided herein can also include all isotopes of atoms occurring in the intermediates or final compounds. Isotopes include those atoms having the same atomic number but different mass numbers. For example, isotopes of hydrogen include hydrogen, tritium, and deuterium.

[0162] Also provided herein are salts of the compounds described herein. It is understood that the disclosed salts can refer to derivatives of the disclosed compounds wherein the parent compound is modified by converting an existing acid or base moiety to its salt form. Examples of the salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. The salts of the compounds provided herein include the conventional non-toxic salts of the parent compound formed, for example, from non-toxic inorganic or organic acids. The salts of the compounds provided herein can be synthesized from the parent compound that contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or an organic solvent or in a mixture of the two. In various aspects, nonaqueous media like ether, ethyl acetate, alcohols (e.g., methanol, ethanol, isopropanol, or butanol), or acetonitrile (ACN) can be used.

[0163] As used herein, chemical structures that contain one or more stereocenters depicted with dashed and bold bonds are meant to indicate the absolute stereochemistry of the stereocenter(s) present in the chemical structure. As used herein, bonds symbolized by a simple line do not indicate a stereo-preference. Unless otherwise indicated to the contrary, chemical structures, which include one or more stereocenters, illustrated herein without indicating absolute or relative stereochemistry encompass all possible stereoisomeric forms of the compound (e.g., diastereomers and enantiomers) and mixtures thereof. Structures with a single bold or dashed line and at least one additional simple line encompass a single enantiomeric series of all possible diastereomers.

[0164] The terms for various functional groups as used herein are not intended to be limited to monovalent radicals and may include polyvalent radical groups as appropriate, such as divalent, trivalent, tetravalent, pentavalent, and hexavalent groups, and the like, based on the position and location of such groups in the compounds described herein as would be readily understood by10046-676W01: 8637 YU the skilled person.

[0165] “Z1,” “Z2,” “Z? and “Z4” are used herein as generic symbols to represent various specific substituents. These symbols can be any substituent, not limited to those disclosed herein, and when they are defined to be certain substituents in one instance, they can, in another instance, be defined as some other substituents.

[0166] A dash

[0167]

[0168] that is not between two letters or symbols is used to indicate a point of attachment for a substituent. For example, -(C=0)NH2 is attached through the carbon of the keto (C=O) group.

[0169] The term “aliphatic” as used herein refers to a non-aromatic hydrocarbon group and includes branched and unbranched, alkyl, alkenyl, or alkynyl groups.

[0170] As used herein, the term “alkyl” refers to saturated, straight-chained or branched saturated hydrocarbon moieties. Unless otherwise specified, C1-C24 (e.g., C1-C22, C1-C20, C1-C18, C1-C16, C1-C14, C1-C12, C1-C10, C1-C8, C1-C6, or C1-C4) alkyl groups are intended. Examples of alkyl groups include methyl, ethyl, propyl, 1-methyl-ethyl, butyl, 1 -methyl -propyl, 2-methyl-propyl, 1,1-dimethyl-ethyl, pentyl, 1 -methyl -butyl, 2-methyl-butyl, 3 -methyl -butyl, 2,2- dimethyl -propyl, 1-ethyl-propyl, hexyl, 1,1 -dimethyl -propyl, 1,2-dimethyl-propyl, 1 -methyl¬ pentyl, 2-methyl -pentyl, 3-methyl-pentyl, 4-methyl-pentyl, 1,1 -dimethyl -butyl, 1,2-dimethyl- butyl, 1,3-dimethyl-butyl, 2,2-dimethyl-butyl, 2,3-dimethyl-butyl, 3,3-dimethyl-butyl, 1 -ethylbutyl, 2-ethyl-butyl, 1,1,2-trimethyl -propyl, 1,2,2-trimethyl-propyl, 1-ethyl-l-methyl-propyl, 1-ethyl-2-methyl-propyI, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, and the like. Alkyl substituents may be unsubstituted or substituted with one or more chemical moieties. The alkyl group can be substituted with one or more groups including, but not limited to, hydroxyl, halogen, acyl, alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, aldehyde, amino, cyano, carboxylic acid, ester, ether, ketone, nitro, phosphonyl, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, or thiol, as described below, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied. It is further understood that throughout the specification, “alkyl” can also be referred to as a linking group of saturated hydrocarbons that are divalent radicals. In other words, in a broader description, the term “alkyls” also encompasses alkylenes. It is further understood that the term “alkyl” covers saturated hydrocarbons that are multivalent radicals.

[0171] 'Throughout the specification “alkyl” is generally used to refer to both unsubstituted alkyl groups and substituted alkyl groups; however, substituted alkyl groups are also specifically referred to herein by identifying the specific substituent(s) on the alkyl group. For example, the term “halogenated alkyl” specifically refers to an alkyl group that is substituted with one or more10046-676W01; 8637 YU halides (halogens; e.g., fluorine, chlorine, bromine, or iodine). The term “alkoxyalkyl” specifically refers to an alkyl group that is substituted with one or more alkoxy groups, as described below. The term “alkylamino” specifically refers to an alkyl group that is substituted with one or more amino groups, as described below, and the like. When “alkyl” is used in one instance and a specific term such as “alkyl alcohol” is used in another, it is not meant to imply that the term “alkyl” does not also refer to specific terms such as “alkylalcohol” and the like.

[0172] This practice is also used for other groups described herein. That is, while a term such as “cycloalkyl” refers to both unsubstituted and substituted cycloalkyl moieties, the substituted nioieties can, in addition, be specifically identified herein; for example, a particular' substituted cycloalkyl can be referred to as, e.g., an “alkylcycloalkyl.” Similarly, a substituted alkoxy can be specifically referred to as, e.g., a “halogenated alkoxy,” a particular substituted alkenyl can be, e.g., an “alkenylalcohol,” and the like. Again, the practice of using a general term, such as “cycloalkyl,” and a specific term, such as “alkylcycloalkyl,” is not meant to imply that the general term does not also include the specific term.

[0173] The term "heteroalkyl " refers to an alkyl group, which further includes at least one heteroatom (e.g., 1, 2, 3, or 4 heteroatoms) selected from oxygen, nitrogen, or sulfur within (i.e., inserted between adjacent carbon atoms of) and / or placed at one or more terminal position(s) of the parent chain. By way of example, a heteroCi -ealkyl (which may also be designated a Cu eheteroalkyl) group includes, but is not limited to, the following structures:

[0174]

[0175] As used herein, the term “alkenyl” refers to unsaturated, straight-chained, or branched hydrocarbon moieties containing a double bond. Unless otherwise specified, C2-C24 (e.g., C2-C22, C2-C20, C2-C18, C2-C16, C2-C14, C2-C12, C2-C10, C2-C8, C2-C6, or C2-C4) alkenyl groups are intended. Alkenyl groups may contain more than one unsaturated bond. Examples include ethenyl, 1 -propenyl, 2-propenyl, 1 -methylethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-l- propenyl, 2-methyl-l -propenyl, l-methyl-2-propenyl, 2-methyl-2-propenyl, 1 -pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-l-butenyl, 2-methyl- 1-butenyl, 3-methyl- 1-butenyl, l-methyl-2-butenyl, 2-methyl -2-butenyl, 3-methyl-2-butenyl, l-methyl-3-butenyl, 2-methyl-3-butenyl, 3-methyl-3-butenyl, 1,1 -dimethyl -2-propenyl, 1,2-dimethyl-l-propenyl, l,2-dimethyl-2-propenyl, 1 -ethyl- 1 -propenyl, 1-ethyl-2-propenyl, 1 -hexenyl, 2 -hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1 -methyl -1 -pentenyl, 2-methyl-l -pentenyl, 3-methyl- 1 -pentenyl, 4-methyl-l- pentenyl, l-methyl-2 -pentenyl, 2-methyl-2 -pentenyl, 3-methyl-2-pentenyl, 4-methyl-2-penienyl,10046-676W01; 8637 YU 1 -methyl- 3-pentenyl, 2-methy]-3-pentenyl, 3-methyl-3-pentenyl, 4-methyl-3-pentenyl, 1-methyl- 4-pentenyl, 2-methyl-4-pentenyl, 3-methyl-4-pentenyl, 4-methyl-4-pentenyl, 1 -dimethyl-2-butenyl, l,l-dimethyl-3-butenyl, 1,2-dimethyl-l -butenyl, l,2-dimethyl-2-butenyl, 1,2-dimethyl-3-butenyl, 1,3-dimethyl-l -butenyl, l,3-dimethyl-2-butenyl, l,3-dimethyl-3-butenyl, 2,2-dimethyl-3-butenyl, 2,3-dimethyl- 1 -butenyl, 2,3-dimethyl-2-butenyl, 2,3-dimethyl-3-butenyl, 3,3-dimethyl-l-butenyl, 3,3-dimethyl-2-butenyl, 1 -ethyl- 1 -butenyl, l-ethyl-2-butenyl, l-ethyl-3-butenyl, 2-ethyl-l-butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl, l,l,2-trimethyl-2-propenyl, 1-ethyl-l-methyl-2 -propenyl, l-ethyl-2 -methyl -1 -propenyl, and 1 -ethyl-2-methyl-2-propenyl. The term “vinyl” refers to a group having the structure -CH=CH2; 1 -propenyl refers to a group with the structure -CH=CH-CH3; and 2-propenyl refers to a group with the structure -CH2-CH=CH2. Asymmetric structures such as (Z^Z^C-CCZEZ4) are intended to include both the E and 7. isomers. This can be presumed in structural formulae herein wherein an asymmetric alkene is present, or it can be explicitly indicated by the bond symbol C=C. Alkenyl substituents may be unsubstituted or substituted with one or more chemical moieties. Examples of suitable substituents include, for example, alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, acyl, aldehyde, amino, cyano, carboxylic acid, ester, ether, halide, hydroxyl, ketone, nitro, phosphonyl, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, or thiol, as described below, provided that the substituents are sterically compatible and the rules of chemical bonding and strain energy are satisfied.

[0176] As used herein, the term “alkynyl” represents straight-chained or branched hydrocarbon moieties containing a triple bond. Unless otherwise specified, C2-C24(e.g., C2-C24, C2-C20, C2-Ci8, C2-C16, C2-C14, C2-C12, C2-C10, C2-C8, C2-C6, or C2-C4) alkynyl groups are intended.

[0177] Alkynyl groups may contain more than one unsaturated bond. Examples include (U-Ce-alkynyl, such as ethynyl, 1-propynyl, 2-propynyl (or propargyl), 1-butynyl, 2-butynyl, 3-butynyl, 1-methyl -2-propynyl, 1 -pentynyl, 2 -pentynyl, 3-pentynyl, 4-pentynyl, 3-methyl- 1-butynyl, 1-methyl -2-butynyl, l-methyl-3-butynyl, 2-methyl-3-butynyl, l,l-dimethyl-2-propynyl, l-ethyl-2-propynyl, 1 -hexynyl, 2 -hexynyl, 3-hexynyl, 4-hexynyl, 5-hexynyl, 3-methyl- 1 -pentynyl, 4- methyl-1 -pentynyl, l-methyl-2 -pentynyl, 4-methyl-2 -pentynyl, l-methyl-3-pentynyl, 2-methyl-3-pentynyl, 1 -methyl -4-pentynyl, 2-methyl-4-pentynyl, 3-methyl-4-pentynyl, l,l-dimethyl-2-butynyl, l,l-dimethyl-3-butynyl, l,2-dimethyl-3-butynyl, 2,2-dimethyl-3-butynyl, 3,3-dimethyl-1-butynyl, 1-ethyl-2-butynyl, l-ethyl-3-butynyl, 2-ethyl-3-butynyl, and 1 -ethyl- 1 -methyl -2-propynyl. Alkynyl substituents may be unsubstituted or substituted with one or more chemical moieties. Examples of suitable substituents include, for example, alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, acyl, aldehyde, amino, cyano, carboxylic acid, ester, ether, halide, hydroxyl,10046-676W01; 8637 YU ketone, nitro, phosphonyl, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, or thiol, as described below.

[0178] As used herein, the term “aryl,” as well as derivative terms such as aryloxy, refers to groups that include an aromatic carbocyclic group of from 3 to 50 carbon atoms. Aryl groups can include a single ring or multiple condensed rings. In some examples, aryl groups include C6-C10 aryl groups. Examples of aryl groups include, but are not limited to, benzene, phenyl, biphenyl, naphthyl, tetrahydronaphthyl, phenylcyclopropyl, phenoxybenzene, and indanyl. The term “aryl” also includes “heteroaryl,” which is defined as a group that contains an aromatic group that has at least one heteroatom incorporated within the ring of the aromatic group. Examples of heteroatoms include, but are not limited to, nitrogen, oxygen, sulfur, and phosphorus. The term “non-heteroaryl,” which is also included in the term “aryl,” defines a group that contains an aromatic group that does not contain a heteroatom. The aryl substituents may be unsubstituted or substituted with one or more chemical moieties. Examples of suitable substituents include, for example, alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, acyl, aldehyde, amino, cyano, carboxylic acid, ester, ether, halide, hydroxyl, ketone, nitro, phosphonyl, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, or thiol as described herein. The term “biaryl” is a specific type of aryl group and is included in the definition of aryl. Biaryl refers to two aryl groups that are bound together via a fused ring structure, as in naphthalene, or are attached via one or more carbon-carbon bonds, as in biphenyl.

[0179] The term “cycloalkyl” as used herein is a non-aromatic carbon-based ring composed of at least three carbon atoms. Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc. The term “heterocycloalkyl” is a cycloalkyl group as defined above where at least one of the carbon atoms of the ring is substituted with a heteroatom such as, but not limited to, nitrogen, oxygen, sulfur, or phosphorus. The cycloalkyl group and heterocycloalkyl group can be substituted or unsubstituted. The cycloalkyl group and heterocycloalkyl group can be substituted with one or more groups including, but not limited to, alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, acyl, aldehyde, amino, cyano, carboxylic acid, ester, ether, halide, hydroxyl, ketone, nitro, phosphonyl, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, or thiol as described herein.

[0180] The term “cycloalkenyl” as used herein is a non-aromatic carbon-based ring composed of at least three carbon atoms and containing at least one double bound, i.e., C=C. Examples of cycloalkenyl groups include, but are not limited to, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, cyclohexadienyl, and the like. The term “heterocycloalkenyl” is a type of cycloalkenyl group as defined above and is included within the meaning of the term10046-676W01; 8637 YU “cycloalkenyl,” where at least one of the carbon atoms of the ring is substituted with a heteroatom such as, but not limited to, nitrogen, oxygen, sulfur, or phosphorus. The cycloalkenyl group and heterocycloalkenyl group can be substituted or unsubstituted. The cycloalkenyl group and heterocycloalkenyl group can be substituted with one or more groups including, but not limited to, alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, acyl, aldehyde, amino, cyano, carboxylic acid, ester, ether, halide, hydroxyl, ketone, nitro, phosphonyl, silyl, sulfo-oxo, sulfonyl, sulfone, sulfoxide, or thiol as described herein.

[0181] The term “cyclic group” is used herein to refer to either aryl groups, non-aryl groups (z.e., cycloalkyl, heterocycloalkyl, cycloalkenyl, and heterocycloalkenyl groups), or both. Cyclic groups have one or more ring systems (e.g., monocyclic, bicyclic, tricyclic, polycyclic, etc.) that can be substituted or unsubstituted. A cyclic group can contain one or more aryl groups, one or more non-aryl groups, or one or more aryl groups and one or more non-aryl groups.

[0182] The term “acyl” as used herein is represented by the formula -C(O)Z1where Z1can be a hydrogen, hydroxyl, alkoxy, alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above. As used herein, the term “acyl” can be used interchangeably with “carbonyl.” Throughout this specification “C(O)” or “CO” is a shorthand notation for C=O.

[0183] The term “acetal” as used herein is represented by the formula (Z1Z2)C(=OZ3)(=OZ4), where Z1, Z2, Z3, and Z4can be, independently, a hydrogen, halogen, hydroxyl, alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0184] The term “alkanol” as used herein is represented by the formula Z1OH, where Z1can be an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0185] As used herein, the term “alkoxy” as used herein is an alkyl group bound through a single, terminal ether linkage; that is, an “alkoxy” group can be defined as to a group of the formula Z1-O-, where Z1is unsubstituted or substituted alkyl as defined above. Unless otherwise specified, alkoxy groups wherein Z1is a C1-C24 (e.g., C1-C22, C1-C20, C1-C18, C1-C16, C1-C14, Ci-C12, C1-C10, Ci-Cs, Ci-Ce, or C1-C4) alkyl group are intended. Examples include methoxy, ethoxy, propoxy, 1 -methyl-ethoxy, butoxy, 1 -methyl -propoxy, 2-methyl -propoxy, 1,1 -dimethyl- ethoxy, pentoxy, 1 -methyl -butyl oxy, 2-methyl-butoxy, 3-methyl-butoxy, 2,2-di-methyl-propoxy, 1 -ethyl -propoxy, hexoxy, 1,1-dimethyl-propoxy, 1,2-dimethyl-propoxy, 1-methyl-pentoxy, 2-methyl -pentoxy, 3-methyl -pentoxy, 4-methyl-penoxy, 1,1-dimethyl-butoxy, 1,2-dimethyl- butoxy, 1,3-dimethyl-butoxy, 2,2-dimethyl-butoxy, 2,3-dimethyl-butoxy, 3,3-dimethyl-butoxy,10046-676W01; 8637 YU 1 -ethyl -butoxy, 2 -ethylbutoxy, 1,1,2-trimethyl-propoxy, 1, 2, 2-trimethyl -propoxy, 1 -ethyl- 1-methyl -propoxy, and l-ethyl-2-methyl -propoxy.

[0186] The term “aldehyde” as used herein is represented by the formula -C(O)H. Throughout this specification “C(O)” is a shorthand notation for C=O.

[0187] The terms “amine” as used herein are represented by the formula — NR1R2, where R1and R2can each be substitution groups as described herein, such as hydrogen, an alkyl, halogenated alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0188] The term “amino” as used herein are represented by the formula — NZ1Z2Z3, where Z1, Z2, and / / can each be substitution group as described herein, such as hydrogen, an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloal kyl, or heterocycloalkenyl group described above.

[0189] The terms “amide” or “amido” as used herein are represented by the formula — C(O)NZlZ2, where Zland Z2can each be substitution group as described herein, such as hydrogen, an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0190] The term “anhydride” as used herein is represented by the formula Z‘C(O)OC(O)Z2where Z1and Z2, independently, can be an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0191] The term “cyclic anhydride” as used herein is represented by the formula:

[0192]

[0193] where Z1can be an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0194] The term “azide” as used herein is represented by the formula -N=N=N.

[0195] The term “carboxylic acid” as used herein is represented by the formula — C(())OH. A “carboxylate” or “carboxyl” group as used herein is represented by the formula — C(O)O •

[0196] As used herein, the term “carbamyl” refers to a group of formula -C(0)NIl2.

[0197] A “carbonate ester” group as used herein is represented by the formula Z!OC(O)OZ2. The term “cyano” as used herein is represented by the formula --CN.

[0198] The term “ester” as used herein is represented by the formula — OCiOiZ' or10046-676W01; 8637 YU — C(O)OZ1, where Z1can be an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0199] The term “ether” as used herein is represented by the formula Z’ OZk where Z1and Z2can be, independently, an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloal kenyl group described above.

[0200] The term “epoxy” or “epoxide” as used herein refers to a cyclic ether with a three atom ring and can represented by the formula:

[0201] 2^ O

[0202]

[0203] where Zl, Z2, Z3, and Z4can be, independently, an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above The term “ketone” as used herein is represented by the formula Z1C(0)Z2, where Z1and Z2can be, independently, an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0204] The term “halide” or “halogen” or “halo” as used herein refers to fluorine, chlorine, bromine, and iodine.

[0205] The term “hydroxyl” as used herein is represented by the formula — OH.

[0206] The term “nitro” as used herein is represented by the formula — NO2.

[0207] The term “phosphonyl” is used herein to refer to the phospho-oxo group represented by the formula — P(O)(OZ1)2, where Z1can be hydrogen, an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0208] The term “silyl” as used herein is represented by the formula — SiZ1Z2Z3, where Z1, Z2, and Z3can be, independently, hydrogen, alkyl, alkoxy, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0209] The term “sulfonyl” or “sulfone” is used herein to refer to the sulfo-oxo group represented by the formula — S(O)2Z1, where Z1can be hydrogen, an alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

[0210] The term “sulfide” as used herein comprises the formula

[0211]

[0212] The term “thiol” as used herein is represented by the formula — SH.

[0213] The term “sulfonylamino” or “sulfonamide,” as used herein, is represented by the formula -SlOfiNH-.

[0214] In general, the inclusion of the prefix “alk” in front of a substituent name indicates there10046-676W01; 8637 YU is an alkyl group (as defined herein) connecting the named substituent with the rest of the compound. For example, "alkaryl" (which is a subset of alkyl) refers to an alkyl group substituted by an aryl group, wherein the point of attachment is on the alkyl moiety and "alkheteroaryl" (which is a subset of "alkyl") refers to an alkyl group substituted by a heteroaryl group, wherein the point of attachment is on the alkyl moiety. The number of carbon atoms may be specified in the alkyl chain, the named substituent, or both. For example, C1-2alkC6aryl refers to a phenyl ring (which may be substituted) connected via a 1-2 carbon alkylene group.

[0215] Affixing the suffix ”-ene" to a group indicates the group is a polyvalent moiety, e.g., boned to two or more groups. Alkylene is the polyvalent moiety of alkyl, alkenylene is the divalent moiety of alkenyl, alkynylene is the divalent moiety of alkynyl, heteroalkylene is the divalent moiety of heteroalkyl, heteroalkenylene is the divalent moiety of heteroalkenyl, heteroalky nylene is the divalent moiety of heteroalkynyl, carbocyclylene is the divalent moiety of carbocyclyl, heterocyclylene is the divalent moiety of heterocyclyl, arylene is the divalent moiety of aryl, and heteroarylene is the divalent moiety of heteroaryl.

[0216] “R1,” “R2,” “R3,” “R“,” etc., where n is some integer, as used herein can, independently, possess one or more of the groups listed above. For example, if R1is a straight chain alkyl group, one of the hydrogen atoms of the alkyl group can optionally be substituted with a hydroxyl group, an alkoxy group, an amino group, an alkyl group, a halide, and the like. Depending upon the groups that are selected, a first group can be incorporated within a second group or, alternatively, the first group can be pendant (i.e., attached) to the second group. For example, with the phrase “an alkyl group comprising an amino group,” the amino group can be incorporated within the backbone of the alkyl group. Alternatively, the amino group can be attached to the backbone of the alkyl group. The nature of the group(s) that is (are) selected will determine if the first group is embedded or attached to the second group.

[0217] As used herein, Me refers to a methyl group; OMe refers to a methoxy group; and z-Pr refers to an isopropyl group.

[0218] As used herein, the designation of a polyvalent moiety without specifying the specific order of attachment is intended to cover all possible arrangements. By way of example, a compound that is represented by the formula:

[0219] A-X-B

[0220] wherein X is NHC(=O) embraces both

[0221] O O

[0222] J, B A. A.

[0223] N N B

[0224] H and H10046-676W01; 8637 YU As used herein, a chemical bond depicted: represents either a single, double, or triple bond, valency permitting. By way of example,

[0225]

[0226] and

[0227] An electron-withdrawing group is a functional group or atom that pulls electron density towards itself, away from other portions of the molecule, e.g., through resonance and / or inductive effects. Exemplary electron-withdrawing groups include F, Cl, Br, I, NO2, CN, SO2R, SO3R, SO2. NR2, C(O)R1a, C(O)OR, and C(0)NR2 (wherein R is H or an alkyl, aryl, heteroaryl, cycloalkyl, heterocyclyl group) as well as alkyl group substituted with one or more of those group.

[0228] An electron-donating group is a functional group or atom that pushes electron density away from itself towards other portions of the molecule, e.g., through resonance and / or inductive effects. Exemplary electron-donating groups include unsubstituted alkyl or aryl groups, OR and N(R)2, and alkyl groups substituted with one or more OR and N(R)2groups.

[0229] Unless stated to the contrary, a formula with chemical bonds shown only as solid lines and not as wedges or dashed lines contemplates each possible stereoisomer or mixture of stereoisomer (e.g., each enantiomer, each diastereomer, each meso compound, a racemic mixture, or scalemic mixture).

[0230] Compositions, Systems, and Methods

[0231] Disclosed herein are compositions, systems, and methods. For example, disclosed herein are molecularly functionalized biomass-derived hydrogels and methods of making and use thereof.

[0232] For example, disclosed herein are molecularly functionalized biomass-derived hydrogel, comprising a polysaccharide derived from a biomass functionalized with a plurality of thermoresponsive alkylations and a plurality of zwitterionic functionalizations.

[0233] The term “biomass,” as used herein, refers to living or dead biological material that can be used in one or more of the disclosed compositions, systems, or methods.

[0234] For example, the biomass can comprise carbohydrates, such as cellulose and cellulose derivatives, hemicelluloses, starch and modified starches, pectins, chitin, chitosan, gums / galactomannans, alginates / agar / carrageenans, oligosaccharides and / or monosaccharides; derivatives thereof; mixtures thereof; and / or breakdown products (e.g., metabolites) thereof. The biomass can be a native, modified, and / or derivatives version of any of the above.10046-676W01; 8637 YU For example, the “biomass” can comprise food waste. The term “food waste” as used herein includes, but is not limited to, any food or an inedible part of food removed from the food supply chain at any point such that it is not consumed by a human and / or animal.

[0235] In the disclosed compositions and methods the “biomass” can comprise any cellulosic, lignocellulosic, and / or chitinous biomass and can include materials comprising cellulose, starch, chitosan, and optionally hemicellulose, lignin, starch, oligosaccharides and / or monosaccharides, their mixtures, and breakdown products (e.g., metabolites). Biomass can also comprise additional components, such as protein and / or lipid. Biomass can be derived from a single source, or biomass can comprise a mixture derived from more than one source. Some specific examples of suitable biomasses that can be used in the disclosed methods include, but are not limited to, bioenergy crops, agricultural residues, municipal solid waste, industrial solid waste, sludge from paper manufacture, yard waste, wood, and forestry waste. Additional examples of suitable types of biomass include, but are not limited to, corn grain, corn cobs, crop residues such as corn husks, corn stover, grasses, wheat, wheat straw, hay, rice straw, switchgrass, waste paper, sugar cane bagasse, sorghum, soy, components obtained from milling of grains, trees (e.g., pine), branches, roots, leaves, wood chips, wood pulp, sawdust, shrubs and bushes, vegetables, fruits, flowers, animal manure, multi-component feed, and crustacean biomass ( / .<?., chitinous biomass).

[0236] Lignocellulosic biomass typically comprises of three major components: cellulose, hemicellulose, and lignin, along with some extractive materials (Sjostorm, E. Wood Chemistry: Fundamentals and Applications, 2nd ed„ 1993, New York.). Depending on the source, their relative compositions usually vary to certain extent.

[0237] Cellulose is the most abundant polymer on Earth and enormous effort has been put into understanding its structure, biosynthesis, function, and degradation (Stick, R. V. Carbohydrates - The Sweet Molecules of Life, 2001, Academic Press, New York.). Cellulose is a polysaccharide comprising a linear chain of several hundred to over ten thousand β(1→4) linked D-glucose units. The chains are hydrogen bonded either in parallel or anti-parallel manner which imparts more rigidity to the structure, and a subsequent packaging of bound-chains into microfibrils forms the ultimate building material of the nature.

[0238] Hemicellulose is the principal non-cellulosic polysaccharide in lignocellulosic biomass. Hemicellulose is a branched heteropolymer, consisting of different sugar monomers with 500- 3000 units. Hemicellulose is usually amorphous.

[0239] Lignin is the most complex naturally occurring high-molecular weight polymer (Hon, D. N. S.; Shiraishi, N., Eds., Wood and Cellulosic Chemistry, 2nded., 2001, Marcel Dekker, Inc.,10046-676W01; 8637 YU New York.). Lignin is relatively hydrophobic and aromatic in nature, but lacks a defined primary structure. Softwood lignin primarily comprises guaiacyl units, and hardwood lignin comprises both guaiacyl and syringyl units.

[0240] The lignocellulosic biomass can, in some examples, be chosen from softwood or hardwood. Cellulose content in both hardwood and softwood is 43 ± 2%. Typical hemicellulose content in wood is 28-35 wt%, depending on type of wood. Lignin content in hardwood is 18-25% while softwood may contain 25-35% of lignin.

[0241] Chitinous biomass can, in some examples, comprise an arthropod biomass, a fungi biomass, or a combination thereof. An arthropod biomass can, for example, comprise the exoskeleton of an arthropod chosen from shrimp, prawn, crayfish, crab, lobster, insect, and combinations thereof.

[0242] In some examples, the polysaccharide is derived from a sustainable biomass feedstock. In some examples, the polysaccharide comprises a carbohydrate. In some examples, a native carbohydrate, a modified carbohydrate, a derivative of a carbohydrate, a breakdown product (e.g., metabolite) of a carbohydrate, or a combination thereof.

[0243] In some examples, the polysaccharide derived comprises carbohydrates, such as cellulose, hemicelluloses, starch, pectins, chitin, chitosan, gums / galactomannans, alginates / agar / carrageenans; derivatives thereof; mixtures thereof; and / or breakdown products (e.g., metabolites) thereof. The biomass can be a native, modified, and / or derivatives version of any of the above.

[0244] In some examples, the polysaccharide comprises cellulose, starch, chitosan, or a combination thereof.

[0245] In some examples, the polysaccharide comprises cellulose. In some examples, the polysaccharide comprises starch. In some examples, the polysaccharide comprises chitosan.

[0246] In some examples, the plurality of thermoresponsive alkylations disrupt the hydrogen bond network of the polysaccharide to facilitate further modifications, and balance hydrophobic and hydrophilic elements to confer thermoresponsiveness, enabling the hydrophobic interaction at elevated temperatures to ease the release of water molecules.

[0247] The thermoresponsive group can, for example, be grafted side chains that can endow an otherwise water-soluble polymer (or polymer network) with LCST-type thermoresponsive phase behavior including N-alkyl amide motifs (for example, N-isopropyl, N-ethyl, N-propyl, N-cyclopropyl, and N, N-dialkyl amide functionalities), cyclic amide (lactam) motifs (for example, pyrrolidone and caprolactam functionalities), oligo(ethylene glycol) motifs (for example, pendant OEG chains of tunable ethyl ene-oxide length and end group), hydroxyalkyl motifs (for10046-676W01; 8637 YU example, hydroxypropyl and hydroxybutyl functionalities), tertiary amine motifs (for example, dialkylaminoalkyl functionalities), or a combination thereof.

[0248] In some examples, the plurality of thermoresponsive alkylations comprise N-alkyl amide motifs (for example, N -isopropyl, N-ethyl, N-propyl, N-cyclopropyl, and N, N-dialkyi amide functionalities), cyclic amide (lactam) motifs (for example, pyrrolidone and caprolactam functionalities), oligo(ethylene glycol) motifs (for example, pendant OEG chains of tunable ethylene-oxide length and end group), hydroxy alkyl motifs (for example, hydroxypropyl and hydroxybutyl functionalities), tertiary amine motifs (for example, dialkylaminoalkyl functionalities), or a combination thereof.

[0249] In some examples, the plurality of thermoresponsive alkylations comprise hydroxypropyl groups, hydroxybutyl groups, or a combination thereof.

[0250] In some examples, the polysaccharide comprises cellulose and the plurality of thermoresponsive alkylations comprise hydroxypropyl groups. In some examples, the polysaccharide comprises starch and the plurality of thermoresponsive alkylations comprise hydroxybutyl groups. In some examples, the polysaccharide comprises chitosan and the plurality of thermoresponsive alkylations comprise hydroxybutyl groups.

[0251] In some examples, the plurality of zwitterionic functionalizations are derived from a zwitterionic agent comprising sulfobetaines (quaternary ammonium paired with sulfonate), carboxybetaines (quaternary ammonium paired with carboxylate), phosphobetaines / phosphorylcholine-like groups (quaternary ammonium or phosphonium paired with phosphate, phosphonate, or related oxyanions), or a combination thereof.

[0252] In some examples, the plurality of zwitterionic functionalizations are derived from a zwitterionic agent comprising (3 -(( 3-chloropropyl)dimethylammonio)propane- 1 -sulfonate).

[0253] In some examples, the molecularly functionalized biomass-derived hydrogel further comprises a salt.

[0254] In some examples, the salt comprises a hydroscopic salt.

[0255] In some examples, the salt comprises a lithium salt, a calcium salt, a magnesium salt, a zinc salt, an aluminum salt, an iron salt, a copper salt, a sodium salt, a potassium salt, an ammonium salt, or a combination thereof.

[0256] In some examples, the salt comprises a chloride salt, a bromide salt, an iodide salt, a hydroxide salt, a carbonate salt, an acetate salt, a perchlorate salt, a sulfate salt, a nitrate salt, or a combination thereof.

[0257] In some examples, the salt comprises Lithium chloride (LiCl), lithium bromide (LiBr), lithium iodide (Lil), calcium chloride (CaCl2), calcium bromide (CaBr2), magnesium chloride10046-676W01; 8637 YU (MgCl2), magnesium bromide (MgBr2), zinc chloride (ZnCl2), aluminum chloride (AlCl3, typically as hydrates / complexes), ferric chloride (FeCl3), copper(II) chloride (CuCl2), sodium hydroxide (NaOH), potassium hydroxide (KOH), potassium carbonate (K2CO3), sodium carbonate (Na2CO3), potassium acetate (KOAc), sodium acetate (NaOAc), magnesium perchlorate (Mg(ClO4)2), calcium perchlorate (Ca(C104)2.), sodium perchlorate (NaClO4), potassium perchlorate (KCIO4), sodium sulfate (Na2SO4, notably as hydrates), magnesium sulfate (MgSO4, notably as hydrates), calcium nitrate (Ca(NO3)2), magnesium nitrate (Mg(NO3)2), zinc nitrate (Zn(NOs)2), ammonium nitrate (NH4NO3), ammonium chloride (NH4Cl), and ammonium sulfate ((NH4)2SO4).

[0258] In some examples, the salt comprises a lithium salt, a calcium salt, or a combination thereof. In some examples, the salt comprises LiCl, CaCl2, or a combination thereof.

[0259] In some examples, the molecularly functionalized biomass-derived hydrogel is crosslinked.

[0260] In some examples, the molecularly functionalized biomass-derived hydrogel is further derived from one or more crosslinking monomers.

[0261] In some examples, the molecularly functionalized biomass-derived hydrogel has a lower critical solution temperature of 10°C or more (e.g., 15°C or more, 20°C or more, 25°C or more, 30°C or more, 35°C or more, 40°C or more, 45°C or more, 50°C or more, 55°C or more, 60°C or more, 65°C or more, 70°C or more, or 75°C or more). In some examples, the molecularly functionalized biomass-derived hydrogel has a lower critical solution temperature of 30°C or more. In some examples, the molecularly functionalized biomass-derived hydrogel has a lower critical solution temperature of 80°C or less (e.g., 75°C or less, 70°C or less, 65 °C or less, 60°C or less, 55°C or less, 50°C or less, 45°C or less, 40°C or less, 35°C or less, 30°C or less, 25°C or less, 20°C or less, or 15°C or less). In some examples, the molecularly functionalized biomass- derived hydrogel has a lower critical solution temperature of 60°C or less. The lower critical solution temperature of the molecularly functionalized biomass-derived hydrogel can range from any of the minimum values described above to any of the maximum values described above. For example, the molecularly functionalized biomass-derived hydrogel has a lower critical solution temperature of from 10 to 80°C (e.g., from 10 to 45°C, from 45 to 80°C, from 10 to 30°C, from 30 to 50°C, from 50 to 80°C, from 10 to 20°C, from 20 to 30°C, from 30 to 40°C, from 40 to 50°C, from 50 to 60°C, from 60 to 70°C, from 70 to 80°C, from 10 to 70°C, from 10 to 60°C, from 10 to 40°C, from 10 to 30°C, from 20 to 80°C, from 30 to 80°C, from 40 to 80°C, from 60 to 80°C, from 20 to 70°C, or from 30 to 60°C). In some examples, the molecularly functionalized biomass-derived hydrogel has a lower critical solution temperature of from 30°C10046-676W01: 8637 YU to 60°C.

[0262] In some examples, the molecularly functionalized biomass-derived hydrogel exhibits enhanced water uptake under a range of relative humidity (RH) conditions (e.g., 5%-100%, such as from 15-60%), stabilizes hygroscopic salts, enables energy-efficient water release at moderate temperatures (~50-60°C), or a combination thereof.

[0263] In some examples, the molecularly functionalized biomass-derived hydrogel demonstrates high sorption-desorption cycling stability.

[0264] In some examples, the molecularly functionalized biomass-derived hydrogel shows a water uptake of 0.1 grams of water per gram of hydrogel (g / g) or more (e.g., 0.2 g / g or more, 0.3 g / g or more, 0.4 g / g or more, 0.5 g / g or more, 0.6 g / g or more, 0.7 g / g or more, 0.8 g / g or more, 0.9 g / g or more, 1 g / g or more, 1.25 g / g or more, 1.5 g / g or more, 1.75 g / g or more, 2 g / g or more, 2.25 g / g or more, 2.5 g / g or more, 3 g / g or more, 3.5 g / g or more, 4 g / g or more, 4.5 g / g or more, 5 g / g or more, 6 g / g or more, 7 g / g or more, 8 g / g or more, or 9 g / g or more) at 15-30% relative humidity (RH). In some examples, the molecularly functionalized biomass-derived hydrogel shows a water uptake of 10 grams of water per gram of hydrogel (g / g) or less (e.g., 9 g / g or less, 8 g / g or less, 7 g / g or less, 6 g / g or less, 5 g / g or less, 4.5 g / g or less, 4 g / g or less, 3.5 g / g or less, 3 g / g or less, 2.5 g / g or less, 2.25 g / g or less, 2 g / g or less, 1.75 g / g or less, 1.5 g / g or less, 1.25 g / g or less, 1 g / g or less, 0.9 g / g or less, 0.8 g / g or less, 0.7 g / g or less, 0.6 g / g or less, 0.5 g / g or less, 0.4 g / g or less, 0.3 g / g or less, or 0.2 g / g or less) at 15-30% relative humidity (RH). The water uptake of the molecularly functionalized biomass-derived hydrogel at 15-30% relative humidity (RH) can range from any of the minimum values described above to any of the maximum values described above. For examples, the molecularly functionalized biomass- derived hydrogel shows a water uptake of from 0.1 to 10 grams of water per gram of hydrogel (e.g., from 0.1 to 5 g / g, from 5 to 10 g / g, from 0.1 to 2 g / g, from 2 to 4 g / g, from 4 to 6 g / g, from 6 to 8 g / g, from 8 to 10 g / g, from 0.1 to 8 g / g, from 0.1 to 6 g / g, from 0.1 to 4 g / g, from 0.5 to 10 g / g, from 1 to 10 g / g, from 2 to 10 g / g, from 4 to 10 g / g, from 6 to 10 g / g, from 0.2 to 9 g / g, or from 0.5 to 8 g / g) at 15-30% relative humidity (RH). In some examples, the molecularly functionalized biomass-derived hydrogel shows a water uptake of from 0.86-1.32 g g-1at 15- 30% relative humidity (RH).

[0265] In some examples, the molecularly functionalized biomass-derived hydrogel has a water collection rate of 1 kg kg1day1or more in outdoor conditions (e.g., 2 kg kg1day!or more, 3 kg kg1day;or more, 4 kg kg;day!or more, 5 kg kg!day1or more, 6 kg kg1day;or more, 7 kg kg1day1or more, 8 kg ke1day ’ or more, 9 kg kg1day1or more, 10 kg kg1day1or more, 11 kg kg-1day-1or more, 12 kg kg-1day-1or more, 13 kg kg-1day-1or more, 14 kg kg-110046-676W01; 8637 YU day-1or more, 15 kg kg-1day-1or more, 20 kg kg-1day-1or more, 25 kg kg-1day-1or more, 30 kg kg-1day-1or more, 35 kg kg-1day-1or more, 40 kg kg-1day-1or more, or 45 kg kg-1day-1or more). In some examples, the molecularly functionalized biomass-derived hydrogel has a water collection rate of 14 kg kg-1day-1or more in outdoor conditions. In some examples, the molecularly functionalized biomass-derived hydrogel has a water collection rate of 50 kg kg1day1or less in outdoor conditions (e.g., 45 kg kg1day1or less, 40 kg kg1day1or less, 35 kg kg1day1or less, 30 kg kg-1day-1or less, 25 kg kg1day1or less, 20 kg kg1day1or less, 15 kg kg-1day-1or less, 14 kg kg-1day-1or less, 13 kg kg-1day-1or less, 12 kg kg-1day-1or less, 11 kg kg1day1or less, 10 kg kg1day1or less, 9 kg kg-1day-1or less, 8 kg kg1day1or less, 7 kg kg1day1or less, 6 kg kg1day1or less, 5 kg kg1day1or less, 4 kg kg1day1or less, 3 kg kg-1day-1or less, or 2 kg kg-1day-1or less). The water collection rate in outdoor conditions of the molecularly functionalized biomass-derived hydrogel can range from any of the minimum values described above to any of the maximum values described above. For example, the molecularly functionalized biomass-derived hydrogel can have a water collection rate of from 1 to 50 kg kg-1day1in outdoor conditions (e.g., from 1 to 25 kg kg1day-1, from 25 to 50 kg kg1day1, from 1 to 10 kg kg1day1, from 10 to 20 kg kg1day-1, from 20 to 30 kg kg1day1, from 30 to 40 kg kg1day-1, from 40 to 50 kg kg1day1, from 1 to 40 kg kg1day-1, from 1 to 30 kg kg-1day1, from 1 to 20 kg kg-1day-1, from 5 to 50 kg kg-1day-1, from 10 to 50 kg kg-1day-1, from 15 to 50 kg kg-1day-1, from 20 to 50 kg kg-1day-1, from 30 to 50 kg kg-1day-1, from 2 to 45 kg kg1day-1, or from 5 to 40 kg kg-1day-1). In some examples, the molecularly functionalized biomass-derived hydrogel can have a water collection rate of from 14 to 50 kg kg-1day-1in outdoor conditions.

[0266] Also disclosed herein are interpenetrating networks derived from any of the molecularly functionalized biomass-derived hydrogels disclosed herein.

[0267] Also disclosed herein are methods of making any of the molecularly functionalized biomass-derived hydrogels disclosed herein.

[0268] Also disclosed herein are methods of molecularly functionalizing a biomass-derived hydrogel, the methods comprising: performing alkylation of a polysaccharide derived from a biomass to thereby functionalize the polysaccharide with a plurality of thermoresponsive alkylations; and integrating zwitterionic groups into the polysaccharide to thereby functionalize the polysaccharide with a plurality of zwitterionic functionalizations. In some examples, the zwitterionic functionalization is performed after the alkylation.

[0269] In some examples, the zwitterionic functionalization comprises a plurality of zwitterionic functionalization steps.10046-676W01; 8637 YU In some examples, the alkylation is via an epoxide ring-opening reaction.

[0270] In some examples, the zwitterionization is via Williamson etherification.

[0271] In some examples, the method further comprises extracting the polysaccharide from the biomass.

[0272] In some examples, the molecularly functionalized biomass-derived hydrogel made by any of the methods disclosed herein comprises any of the molecularly functionalized biomass- derived hydrogels disclosed herein.

[0273] In some examples, the method is a cost-effective large-scale synthesis, for example via supercritical CO₂ processing and / or continuous flow chemistry.

[0274] Also disclosed herein are methods of use of any of the molecularly functionalized biomass-deri ved hydrogels disclosed herein and / or any of the interpenetrating networks disclosed herein.

[0275] In some examples, the method comprises using the molecularly functionalized biomass- derived hydrogel and / or the interpenetrating network for atmospheric water harvesting. In some examples, the method comprises passive or solar-assisted water recovery.

[0276] In some examples, the method comprises using the molecularly functionalized biomass- derived hydrogel and / or the interpenetrating network for humidity control in an enclosed space.

[0277] In some examples, the method comprises using the molecularly functionalized biomass- derived hydrogel and / or the interpenetrating network in a thermal management or passive cooling application.

[0278] In some examples, the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network in pharmaceutical and / or food packaging.

[0279] In some examples, the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network in water collection, water purification, water management, or a combination thereof.

[0280] In some examples, the method comprises using the molecularly functionalized biomass- derived hydrogel and / or the interpenetrating network in water capture, water logistics, process water, humidity control, humidity preservation, humidity packaging, building materials, HVAC integration, thermal management, cooling, gas drying, industrial separations, corrosion control, materials protection, or a combination thereof.

[0281] Also disclosed herein are articles of manufacture comprising any of the molecularly functionalized biomass-derived hydrogels disclosed herein and / or any of the interpenetrating networks disclosed herein.10046-676W01; 8637 YU In some examples, the article comprises an atmospheric water harvesting device, e.g., an indoor and / or outdoor atmospheric water harvesting device.

[0282] In some examples, the article comprises a portable water harvester, a self-sustaining irrigation system, an emergency drinking water device, or a combination thereof.

[0283] EXAMPLES

[0284] The following examples are set forth below to illustrate the methods and results according to the disclosed subject matter. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative methods and results. These examples are not intended to exclude equivalents and variations of the present invention which are apparent to one skilled in the art.

[0285] Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric. There are numerous variations and combinations of measurement conditions, e.g., component concentrations, temperatures, pressures and other measurement ranges and conditions that can be used to optimize the described process.

[0286] Example 1 - A general strategy for synthesizing molecularly functionalized biomass for atmospheric water harvesting

[0287] Described herein is a general strategy for synthesizing molecularly functionalized biomass hydrogels (MFBHs) as efficient atmospheric water harvesting (AWH) sorbents. The strategy involves a two-step molecular engineering approach that converts natural polysaccharides (such as cellulose, starch, and chitosan) into functional hydrogel sorbents by introducing thermoresponsive alkylation and zwitterionic functionalization. This modification enhances water uptake under low relative humidity (RH), stabilizes hygroscopic salts, and enables energy-efficient water release at moderate temperatures (~50-60°C). Unlike conventional synthetic polymer hydrogels, MFBHs utilize sustainable biomass feedstock, ensuring environmental friendliness and scalable production. The hydrogels demonstrate high sorption-desorption cycling stability, achieving water collection rates of up to 14.19 kg kg-1day1in outdoor conditions. The technology offers a sustainable and decentralized approach to water harvesting, particularly beneficial in arid and remote regions.

[0288] Features include, but are not limited to:

[0289] 1. A Generalizable Molecular Engineering Strategy -Presented herein is a universal approach applicable to multiple biomass-derived polysaccharides, enabling their transformation into highly efficient hydrogel sorbents.10046-676W01; 8637 YU 2. Sustainable and Scalable - Unlike traditional synthetic polymer sorbents, MFBHs leverage abundant biomass-based polysaccharides, reducing reliance on petroleum-derived materials while ensuring scalability.

[0290] 3. Enhanced Water Uptake - The integration of zwitterionic groups enhances hygroscopic salt retention, preventing leakage and increasing moisture absorption across a wide range of RH conditions (10%- 100%).

[0291] 4. Energy-Efficient Desorption - The thermoresponsive alkylation imparts a lower critical solution temperature (LCST), enabling efficient water release at mild heating (—50-60°C), significantly reducing energy consumption compared to existing AWH technologies.

[0292] 5. Robust Cycling Stability - Unlike salt-based composites prone to crystallization and degradation, MFBHs exhibit excellent mechanical integrity over multiple sorptiondesorption cycles.

[0293] 6. Versatile and Customizable - The methodology applies to various polysaccharides (cellulose, starch, and chitosan), making it a generalizable platform for sorbent development.

[0294] Problems solved include, but are not limited to:

[0295] 1. Water Scarcity - Provides a decentralized and sustainable solution for water generation, especially in regions with low RH where conventional condensation-based water harvesting methods fail.

[0296] 2. High Energy Costs - Reduces energy input for desorption by utilizing mild heating (e.g., solar energy), unlike conventional desiccant-based AWH systems requiring intensive heat input.

[0297] 3. Environmental Impact - Replaces petroleum-derived polymers with biodegradable, biomass-based alternatives, mitigating plastic pollution and reducing carbon footprint.

[0298] 4. Salt Leakage in Sorbents - Overcomes the salting-out effect seen in conventional salt-polymer hybrid sorbents, ensuring stable water storage and long-term functionality.

[0299] Benefits include, but are not limited to:

[0300] • Eco-Friendly and Sustainable - Uses renewable biomass feedstock rather than synthetic polymers.

[0301] • Broad RH Operability - Efficient water uptake across 15%-60% RH, outperforming conventional desiccants and hygroscopic MOFs.

[0302] • Low Energy Input for Water Release - Requires only 50-60°C for desorption, allowing passive or solar-assisted water recovery.10046-676W01; 8637 YU • Prevention of Salt Leakage - Zwitterionic groups stabilize hygroscopic salts within the hydrogel matrix, unlike traditional salt-polymer hybrids.

[0303] • High Outdoor Performance - Achieves 14.19 kg kg1day1in field tests, demonstrating real-world applicability.

[0304] • Generalized Strategy for Biomass Functionalization - Expands the range of raw materials beyond synthetic polymers and material-specific tailored approaches in traditional biomass utilization, unlocking new possibilities for sustainable material design.

[0305] Industrial production will require optimization of reaction conditions to ensure cost- effective large-scale synthesis, potentially via supercritical CO₂ processing or continuous flow chemistry.

[0306] This class of new sorbents could be potentially applied in many technologic areas where require absorption of polar molecules from air or multicomponent gas or moisture related applications. For examples,

[0307] 1. Humidity Control in Enclosed Spaces - Use in climate regulation for storage rooms, vehicles, and electronics protection.

[0308] 2. Passive Cooling Applications - Utilizing moisture absorption-desorption cycles for temperature regulation.

[0309] 3. Pharmaceutical and Food Packaging - Preventing spoilage through controlled humidity management.

[0310] Applications include, but are not limited to, water collection, water purification, and water management.

[0311] Example 2 - A General Strategy for Synthesizing Molecularly Functionalized Biomass for Atmospheric Water Harvesting

[0312] Water scarcity is a critical global issue, with billions lacking access to clean drinking water. Traditional water extraction methods, such as groundwater pumping, desalination, and rainwater harvesting, require substantial energy input and infrastructure, making them impractical for decentralized water supply, particularly in arid and remote regions. Atmospheric water harvesting (AWH) offers an alternative solution, but existing technologies face significant limitations in efficiency, operability, and sustainability.

[0313] Currently, synthetic polymer-based sorbents such as hydrogels are being developed to capture water from air. While these materials exhibit high water uptake, they often suffer from energy-intensive regeneration, limited long-term stability, and reliance on petroleum-based feedstocks, raising concerns about environmental impact and scalability. Additionally, traditional strategies for utilizing biomass in materials science have been material-specific and tailored,10046-676W01; 8637 YU following a select-and-combine approach, where individual biomass components are selectively modified to serve as adsorbents. However, such approaches lack generalizability and often require complex processing steps to optimize adsorption and desorption properties.

[0314] There is a pressing need for a generalizable and scalable strategy to transform abundant biomass resources into high-performance, energy-efficient water sorbents, overcoming the limitations of both synthetic polymer-based sorbents and traditional biomass utilization methods.

[0315] Presented herein is a universal molecular engineering strategy to functionalize biomass-based polysaccharides for high-performance atmospheric water harvesting. By introducing thermoresponsive alkylation and zwitterionic functionalization into biomass-derived polysaccharides (e.g., cellulose, starch, and chitosan), this approach enables:

[0316] • Enhanced water uptake across broad RH conditions (10%-100%) by stabilizing hygroscopic salts within the hydrogel matrix.

[0317] • Energy-efficient water release via thermoresponsive behavior, requiring only mild heating (~50-60°C) instead of intensive energy input.

[0318] • Superior cycling stability, preventing structural degradation and salt leakage, allowing for long-term, practical deployment.

[0319] • Scalable and sustainable production, utilizing abundant and biodegradable biomass feedstocks instead of synthetic petroleum -based polymers.

[0320] Field tests demonstrate water collection rates of up to 14.19 kg kg1day-1, significantly outperforming conventional hygroscopic materials while maintaining superior environmental sustainability.

[0321] Features include, but are not limited to:

[0322] • A generalizable molecular engineering strategy for biomass functionalization, applicable to various polysaccharides.

[0323] • High water uptake and low energy regeneration, making it highly efficient across diverse environmental conditions.

[0324] • Stable and reusable over multiple cycles, ensuring long-term operational reliability.

[0325] • Scalable and eco-friendly, enabling sustainable production and application.

[0326] Benefits include, but are not limited to:

[0327] • Sustainable and Biodegradable: Replaces petroleum-derived synthetic sorbents with environmentally friendly, biomass-based alternatives.

[0328] • Low Energy Consumption: Reduces the cost of water release by utilizing solar- assisted or passive heating.10046-676W01; 8637 YU • Decentralized and Off-Grid Capabilities: Enables water access in remote, arid regions without reliance on centralized infrastructure.

[0329] • Customizable for Different Humidity Conditions: Adaptable to varying climates through rational molecular design.

[0330] Markets include, but are not limited to:

[0331] • Atmospheric water harvesting and purification for water-scarce regions.

[0332] • Sustainable agriculture for irrigation and soil moisture control.

[0333] • Disaster relief and off-grid water supply for emergency response efforts.

[0334] • Industrial moisture control in storage, packaging, and climate-sensitive environments.

[0335] Example 3 - Molecularly functionalized biomass hydrogels for sustainable atmospheric water harvesting

[0336] Abstract. Atmospheric water harvesting (AWH) offers a promising pathway to alleviate global water scarcity, highlighting the need for environmentally responsible sorbent materials. In this context, the research herein introduces a universal strategy for transforming natural polysaccharides into effective hydrogel sorbents, demonstrated with cellulose, starch, and chitosan. The methodology unites alkylation to graft thermoresponsive groups, thereby enhancing water processability and enabling energy-efficient water release at lower temperatures, with the integration of zwitterionic groups to ensure stable and effective water sorption (Figure 1). The molecularly functionalized cellulose hydrogel, exemplifying the approach, shows favorable water uptake of 0.86-1.32 g g-1at 15–30% relative humidity (RH), along with efficient desorption, releasing 95% of captured water at 60 °C. Outdoor tests highlight the water production rate of up to 14.19 kg kg-1day-1by electrical heating. The proposed molecular engineering methodology, which expands the range of raw materials by leveraging abundant biomass feedstock, has the potential to advance sorbent production and scalable atmospheric water harvesting technologies, contributing to sustainable solutions.

[0337] Introduction. Global water scarcity poses a significant threat to human societies [1, 2], The UNICEF and World Health Organization report that one in three people worldwide lack access to safe drinking water [3], This challenge is central to the United Nations Sustainable Development Goal (SDG) 6, aiming to ensure universal water access and sustainable management by 2030 [4, 5], Given the disparity between population distribution and water availability, identifying universally accessible and decentralized water sources is crucial.

[0338] Atmospheric water, encompassing a vast reserve of over 13,000 cubic kilometers, offers a sustainable freshwater source [6], Exploiting this resource, sorption -based atmospheric water10046-676W01; 8637 YU harvesting (SAWH) has emerged as a viable solution, leveraging the moisture sorptiondesorption capacities of hygroscopic sorbents independent of geographic constraints [7-11].

[0339] The quest for efficient sorbent materials has led to notable advancements. Ideal sorbents are characterized by high water uptake, rapid sorption-desorption kinetics, and operational stability

[0012] . Material candidates in this field include metal organic frameworks (MOFs) [13, 14], salt-based composites [15-17], and hydrogels [18-21], each with distinct benefits. MOFs, for instance, facilitate fast water sorption-desorption, while salt-based composites excel in water uptake. Polymeric hydrogels, with their unique swelling properties and tunable polymer-water interactions, offer high water capacity and tailorable hygroscopicity and hydrability [22, 23]. However, the sustainability of the polymer matrix in these hydrogels is increasingly challenged, for example, often composed of petroleum-derived synthetic vinyl monomers like polyacrylamide, polyacrylic acid, and poly(N-isopropylacrylamide) [24, 25]. The extensive use of such polymers in various sectors is expected to escalate global polymer production, potentially accounting for 20% of global fossil fuel consumption by 2050, underscoring the profound environmental impact of plastics and polymer pollution worldwide

[0026] .

[0340] Natural biomass, particularly polysaccharides, represents a vast resource for functional polymers, constituting over 90% of the world's carbohydrate mass

[0027] . The functional groups on polysaccharides, predominantly hydroxyl groups on glucose units, offer opportunities for various functionalization

[0028] . However, their inherent properties present challenges in functioning as sorption-based atmospheric water harvesting sorbent materials. The dense molecular structure of many polysaccharides affects their hygroscopicity and hydrability, reducing moisture sorption efficiency. These characteristics can also make their processing more complex, often requiring specific solvents for hydrogel production

[0029] . Moreover, the incorporation of hygroscopic salts like lithium chloride (LiCl) and calcium chloride (CaCh) into the hydrogel matrix, though beneficial for water uptake, especially in arid conditions, can lead to reduced hydrability due to salting-out effect, potentially causing salt leakage and compromising water storage within the hydrogel [30, 31],

[0341] Herein, a universal strategy is proposed to molecularly functionalize natural polysaccharides, activating them as efficient sorption-based atmospheric water harvesting hydrogel sorbents (Figure 2). This process begins with alkylation, grafting thermoresponsive groups like hydroxypropyl (HP) or hydroxybutyl (HB), to improve water solubility and confer a lower critical solution temperature (LCST). The temperature-induced hydrophobic interactions facilitate the release of water molecules at lower desorption temperatures and potentially enable the use of low-grade heat sources in practical applications. Subsequently, the introduction of a10046-676W01; 8637 YU zwitterionic agent to the polysaccharide matrix addresses the salting-out issue. The salting-in effect of these zwitterionic groups increases swellability in the presence of salts, due to the dissociation of self-associations between opposite charges on the zwitterionic moiety upon pairing with salt ions. This approach enables the development of molecularly functionalized biomass hydrogels (MFBHs) as effective sorbents from readily available polysaccharides, such as cellulose, starch, and chitosan, all of which have been utilized to validate the versatility of the proposed methodology. The resulting molecularly functionalized cellulose / LiCl hydrogel demonstrates water uptake of 0.86 g g-1at 15%, 1.32 g g-1at 30%, and 2.18 g g-1at 60% relative humidity, respectively. Additionally, it can desorb 80% and 95%’ of absorbed water at 50 °C and 60 °C, respectively. Outdoor tests highlight the water production rate of up to 14.19 kg kg-1day-1, underscoring the practical potential of molecularly functionalized biomass hydrogels. This approach has the potential to advance sorbent development by expanding the range of raw material sources through the activation of earth-abundant biomass resources, thereby contributing to scalable and sustainable atmospheric water harvesting technologies.

[0342] Results

[0343] Preparation and characterization of zwitterionic hydroxypropyl cellulose (ZHPC). Extracted from plants, cellulose, one of the most abundant biomass feedstocks, comprises straight polymer chains interlinked by strong inter- / intramolecular hydrogen bonds [32, 33]. To tailor it for sorption-based atmospheric water harvesting functionality, cellulose is first subjected to hydroxypropylation via an epoxide ring-opening reaction with its hydroxyl groups (Figure 7). The grafted hydroxypropyl group plays dual roles: disrupting the hydrogen bond network to facilitate further modifications, and balancing hydrophobic and hydrophilic elements to confer thermoresponsiveness, enabling the hydrophobic interaction at elevated temperatures to ease the release of water molecules (Figure 8). Precision in the hydroxypropyl substitution level is crucial as it significantly influences the polymer's lower critical solution temperature and impacts subsequent modifications (Figure 9a-Figure 9b). Subsequently, zwitterionic agents (3-((3- chloropropyl)dimethylammonio)propane-l -sulfonate) are attached to the cellulose through Williamson etherification (Figure 10-Figure 12b). The hydroxypropylation and zwitterionization together culminate in the formation of zwitterionic hydroxypropyl cellulose (Figure 3a).

[0344] To achieve different levels of zwitterionization in the zwitterionic hydroxypropyl cellulose, multiple stages of zwitterionization are performed instead of increasing the zwiterionic agent concentration in a single stage, which would lead to more severe side reactions (Figure 12a-Figure 12b). For example, zwitterionic hydroxypropyl cellulose treated with a single stage of zwitterionization is designated as ZHPC-1.10046-676W01; 8637 YU The proton nuclear magnetic resonance (1H NMR) results in Figure 3b, showing peaks at 3.0 ppm (-N(CH3)2-), 2.8 ppm (-CH2SO3), and 1.0 ppm (-CH3 in the hydroxypropyl group), confirm the grafting of both zwitterionic and hydroxypropyl groups. The peaks of -N(CH3)2- (3.0 ppm) and Ci-H anhydroglucose (4.4 ppm) are used to calculate the degree of substitution (DS) of the zwitterionic groups in zwitterionic hydroxypropyl celluloses, revealing degree of substitution values of 0.3, 0.4, and 0.5 for ZHPC-1, ZHPC-2, and ZHPC-3, respectively (Figure 13). The Fourier-transform infrared spectroscopy (FTIR) spectrum (Figure 3c) shows a shift in the hydroxyl groups in cellulose from 3348 cm”1to 3410 cm”1in hydroxypropyl cellulose and zwitterionic hydroxypropyl cellulose, indicating weakened inter- / intramolecular H-bonds. The peak at 1034 cm"1in ZHPC-3, ascribed to the S=O group's symmetric stretching, further validates successful zwitterionization.

[0345] The crystallinity changes in cellulose post-hydroxypropylation are evidenced by the disappearance of characteristic crystalline peaks at 15.2°, 16.3°, 22.3°, 34.3° in the X-Ray diffraction (XRD) patterns (Figure 3d), corroborating the disruption of strong intermolecular interactions in cellulose.

[0346] Swelling tests in increasing LiCl concentrations show that the swelling ratio of pure cellulose hydrogel initially rises from 5.4 g g“!in 0 M to 5.7 g g”1in 2 M LiCl solution, then decreases to 1.2 g g”1as the salt concentration increases to 6 M, due to the salting-out effect and high environmental osmotic pressure. In contrast, ZHPC-3 hydrogel displays a peak swelling ratio of 11.4 g g"1in 5 M LiCl solution, surpassing cellulose and ZHPC-1 and ZHPC-2 hydrogels (Figure 14). This salt-responsive characteristic plays a pivotal role in atmospheric water harvesting by facilitating higher salt loading and increased swelling upon salt deliquescence under humid conditions, thereby improving water uptake.

[0347] Differential scanning calorimetry (DSC) test shows a shift in the endothermic peak from 44 °C of pure hydroxypropyl cellulose to 50 °C of ZHPC-3 (Figure 15). This peak, evident in the DSC heat flow profile, signifies the phase transition temperature, marking the energy required for disrupting polymer-water interactions. The transition temperature increase in ZHPC-3 is due to its enhanced hydrophilicity from the added zwitterionic groups.

[0348] Atmospheric water harvesting performance of zwitterionic hydroxypropyl celluloses.

[0349] The water vapor sorption-desorption performance of ZHPC-1, 2, and 3 is assessed through dynamic vapor sorption (DVS) testing, which hinges on LiCl deliquescence above -11 % relative humidity, leading to the storage of liquified LiCl solution within the porous gel network (Figure 17)

[0034] , In Figure 4a, the water uptake at 30% relative humidity for ZHPC-1 to ZHPC-3 shows an increase from 0.99 g g"1to 1.32 g g"1, respectively, outperforming the pristine cellulose,10046-676W01; 8637 YU cellulose / LiCl hydrogel, and hydroxypropyl cellulose / LiCl hydrogel. This enhanced performance is attributed to the improved salt loading and swelling behavior upon salt solution exposure post-zwitterionization (Figure 18-Figure 22b). Significantly, ZHPC-3 demonstrates a broad range of water sorption capacity, with 0.86 g g-1at 15% relative humidity and 2.18 g g-1at 60% relative humidity, underlining its versatility under varying humidity conditions (Figure 4b and Figure 23). The barely observed salt leakage in the fully swollen gel after -90% relative humidity sorption attests to its effective salt storage, enabled by the salting-in effect of the zwitterionic structure, which simultaneously prevents leakage, maximizes salt loading, and synergistically enhances water uptake (Figure 24a-Figure 24b). Notably, substituting LiCl with a more cost- effective option like CaCl2slightly undermines but still maintains competitive water uptake performance (Figure 25A-Figure 25b). During desorption, zwitterionic hydroxypropyl celluloses efficiently release 95% of absorbed water at 60 °C. However, ZHPC-3 exhibits slightly reduced water desorption at 50 °C relative to ZHPC-1 and 2, correlating with its higher phase transition temperature (Figure 26a-Figure 26b). DSC analysis in Figure 4c shows ZHPC-3's main water evaporation occurring at 49 °C, aligning with its phase transition temperature (Figure 3f). The distinct peak at 97 °C corresponds to the decomposition of LiCl hydrate (Figure 4c)

[0035] . For the cellulose / LiCl hydrogel, a higher evaporation peak at 55 °C is observed, and additionally, the milder peak of LiCl hydrate provides clear evidence of reduced salt loading due to the absence of zwitterionization functionalization. ZHPC-3's desorption efficacy at different temperatures reveals increased water release with elevated temperatures, most notably between 40 °C and 50 °C, which is influenced by the hydrophobic interaction occurring at 50 °C. Figure 4e and Figure 4f showcase ZHPC-3 ’s advantageous stability over 100 hours of cycling, maintaining consistent water uptake and kinetics, which confirms its material stability and durability.

[0350] An indoor atmospheric water harvesting device is employed to demonstrate ZHPC-3’s water extraction capability (Figure 27). Moisture capture is performed in a custom chamber at targeted relative humidity levels before each water collection test (Figure 28a-Figure 28b). As Figure 4g illustrates, ZHPC-3 consistently achieves advantageous water collection rates: 0.72 g g”1at -15% relative humidity, 1.13 g g-1at -30% relative humidity, and 1.87 g g-1at -60% relative humidity. The difference between water uptake and water collection is attributed to incomplete desorption at the selected temperature and system cooling limitations. The extended cycling tests in Figure 4h reveal an average water collection of 1.13 g g"1at -30% relative humidity, reinforcing its potential for effective water generation, zwitterionic hydroxypropyl cellulose’s favorable atmospheric water harvesting properties at various humidity levels,10046-676W01; 8637 YU compared to other cellulose-based sorbents (Table 1), along with its sustainable origins, positions it as a viable and eco-friendly option for future atmospheric water harvesting endeavors.

[0351] Universality of the molecular functionalization strategy. Extending the molecular functionalization technique initially validated with cellulose, further investigations are conducted with starch and chitosan, given their wide natural reserves and extensive use in both research and industry, highlighting the versatility of the proposed methodology. Starch, widely present in staple plants like corn, potatoes, and rice, is more hydrophilic than cellulose due to its a- 1,4 or 1,6-glycosidic linkages, which afford a looser structure with more accessible hydroxyl groups, in contrast to cellulose’s tightly packed linear structure linked by p- 1,4-glycosidic bonds

[0036] , This inherent structural difference in hydrophilicity necessitates tailored adjustments in the functionalization strategy, as the effectiveness of thermoresponsive groups relies on balancing hydrophilicity with hydrophobicity

[0037] . In this context, hydroxypropyl modified starch demonstrates insufficient hydrophobicity for tliermoresponsiveness. Conversely, hydroxybutyl groups, featuring longer alkyl chains, effectively enhance the overall hydrophobicity. Such a modification enables the tuning of the lower critical solution temperature in hydroxybutyl- modified starch (HBS), which can be varied with the degree of hydroxybutyl substitution (Figure 29 and Figure 30).

[0352] The1H NMR results depicted in Figure 5a confirm the successful functionalization of hydroxybutyl and zwitterionic groups, as evidenced by characteristic peaks at 3.1 ppm (-N(CH3)2-), 3.0 ppm ( -CH2SO3), and 0.9 ppm (-CH3 in the hydroxybutyl group). The degree of substitution for the zwitterionic group in one-stage and two-stage zwitterionized hydroxybutyl- modified starch (ZHBS-1 and ZHBS-2) is quantified at around 0.20 and 0.35, respectively (Figure 31). Pristine starch showcases Type-A crystalline peaks at 15.1°, 17.1°, 18.0°, and 22.8° in its XRD pattern, consistent with the characteristics of raw corn starch utilized in this study. Following the functionalization process, zwitterionized hydroxybutyl-modified starch undergoes a transformation to an amorphous structure, as evidenced in Figure 5b, suggesting a significant alteration in its molecular conformation towards a stretched state. DSC test reveals a lower critical solution temperature of ~60 °C for ZHBS-1, shifting from ~47 °C of hydroxybutyl- modified starch. Notably, ZHBS-2, lacking an endothermic peak, does not exhibit lower critical solution temperature behavior at elevated temperatures, suggesting a significant lower critical solution temperature alteration post-zwitterionization, more pronounced than in the cellulose system. This difference might stem from the lower substitution level of hydroxybutyl in starch compared to hydroxypropyl in cellulose, as hydro xybutyl's greater hydrophobicity necessitates less substitution to achieve a similar lower critical solution temperature as observed in the10046-676W01; 8637 YU zwitterionic hydroxypropyl cellulose system. Both systems, however, incorporate a comparable amount of zwitterionic groups, resulting in increased hydrophilicity. This increase is relatively subtle in the cellulose system but more significant in the starch system due to the sparser hydroxybutyl. Given that lower critical solution temperature depends on the balance between hydrophilic and hydrophobic forces, the rise in zwitterionic levels has a more pronounced effect on the lower critical solution temperature in the starch system.

[0353] ZHBS-1 is chosen for further experimentation to fabricate the zwitterionized hydroxybutyl-modified starch / LiCl hydrogel. This hybrid hydrogel showcases a substantial water uptake improvement, recording 0.56, 0.89, and 1.44 g g-1at 15, 30, and 60% relative humidity respectively (Figure 5d), a notable enhancement over pristine starch (Figure 33). The zwitterionized hydroxybutyl-modified starch / LiCl hydrogel efficiently releases over 90% of absorbed water at 60 °C, rendering it apt for practical applications (Figure 34). Indoor atmospheric water harvesting testing at 30% relative humidity sorption and 60 °C desorption, following the cellulose system setup, demonstrates the zwitterionized hydroxybutyl-modified starch / LiCl hydrogel's consistent performance across 20 cycles, with an average water delivery capacity of 0.80 g g“’ per cycle (Figure 5e and Figure 35).

[0354] Chitosan, derived from the deacetylation of chitin found in crustaceans and insects, is a linear amino polysaccharide composed of P-1, 4-linked D-glucosamine units

[0038] . Its structure mirrors that of cellulose but has a less ordered molecular arrangement due to the variable hydrogen bonding from amino and acetyl groups

[0039] . Similar to starch, hydroxybutyl groups are used for enabling thermoresponsiveness in hydroxybutyl-modified chitosan (HBC), possibly influenced by the differences in group functionality and chain configuration, necessitating a longer carbon chain for hydrophobic interactions compared to cellulose

[0040] , The adaptation of the functionalization method to chitosan is confirmed by the synthesis of zwitterionic hydroxybutyl-modified chitosan (ZHBC), as shown in Figure 5f, with the degree of substitution of the zwitterionic group in ZHBC-1 and ZHBC-2 at approximately 0.20 and 0.35, respectively. Grafting hydroxybutyl alters the crystallinity of pristine chitosan, transforming crystalline peaks at 11.1° and 21.1° to abroad peak at -20°, indicating zwitterionic hydroxybutyl-modified chitosan's amorphous structure (Figure 5g). As shown in Figure 5h, the phase transition behavior of hydroxybutyl-modified chitosan is at 45 °C, which is modifiable by adjusting hydroxybutyl substitution levels (Figure 36 and Figure 37). For ZHBC-1, the lower critical solution temperature increases to ~58 °C, while ZHBC-2, akin to the starch system, does not display lower critical solution temperature behavior within the tested temperature range, suggesting a uniform mechanism governing phase transitions in hydroxybutyl-modified systems based on the10046-676W01; 8637 YU balance between zwitterionic and hydroxybutyl groups. ZHBC-l / LiCl hydrogel showcases enhanced atmospheric water harvesting properties, with water uptake significantly improved to 0.68, 1.09, and 1.67 g g”!at 15, 30, and 60% relative humidity, respectively, outperforming pristine chitosan (Figure 5i and Figure 39). Additionally, it efficiently releases over 95% of absorbed water at 60 °C desorption (Figure 40) and maintains stable cycling over 100 hours (Figure 5 j and Figure 41), highlighting its potential for practical atmospheric water harvesting applications.

[0355] Further enhancements in atmospheric water harvesting properties for both starch and chitosan systems, especially in water uptake without compromising favorable desorption characteristics, can be achieved through the development of interpenetrating network hydrogels. This involves utilizing hydroxybutyl-modified starch and hydroxybutyl -modified chitosan variants with increased hydroxybutyl substitution to achieve a lower LCST (lower critical solution temperature), alongside ZHBS-2 and ZHBC-2, which feature elevated zwitterionic levels conducive to higher salt loading and enhanced swellability (Figure 42a-Figure 42b and Figure 43a-Figure 43b).

[0356] Outdoor atmospheric water harvesting test. The preceding discussions showcase the universality of the proposed molecular functionalization strategy to various natural polysaccharides. The real-world efficacy of the molecularly functionalized biomass hydrogels was assessed through outdoor atmospheric water harvesting test, selecting zwitterionic hydroxypropyl cellulose as the representative material. Given the aqueous nature of the zwitterionic hydroxypropyl cellulose synthesis process, inclusive of zwitterionized hydroxybutyl-modified starch and zwitterionic hydroxybutyl-modified chitosan, substantial quantities could potentially be produced by scaling up the reaction system, as demonstrated in Figure 6a, ’H NMR analysis confirms the molecular consistency of zwitterionic hydroxypropyl cellulose synthesized in scaling production (Figure 44). Bulk zwitterionic hydroxypropyl cellulose / LiCl hydrogels at the hundred-gram level show water uptake comparable to previous results, suggesting the possibility of upscale production (Figure 45).

[0357] The water harvesting setup, depicted in Figure 6b, includes a gel sorbent on a heating plate above a collection base, with a glass cover for condensation and a thermometer to monitor sorbent temperature. The system operates by exposing the sorbent to atmospheric moisture followed by heating under the cover to release and condense the water. Conducted in Austin, USA, the outdoor atmospheric water harvesting test utilized a dual-cycle operation daily from March 1stto 6th, 2024, to extract atmospheric water. Each cycle involved overnight sorption starting from 10:00 pm, continuing until 8:00 am the following day, succeeded by a 4–hour10046-676W01; 8637 YU desorption phase at 60 °C. Subsequently, a daytime stage was initiated at 12:00 pm and lasted until 10:00 pm, incorporating both sorption for 6 hours and a subsequent 4-hour desorption period. Water collection and corresponding ambient conditions are depicted in Figure 6c, totaling 726 mL of collected water as illustrated in Figure 6d, translating to a productivity rate of 1.44 kg kg-1day"1. Based on the outdoor performance, a techno-economic analysis of the water production — accounting for system and operational costs — indicates that the payback period for the water produced, relative to the price of bottled water, would be less than one year (Figure 46). Inductively coupled plasma mass spectrometry (ICP-MS) analysis of the collected water indicates metal ion concentrations significantly below WHO standards, with trace amount of Li+residue possibly resulting from cluster evaporation from the hydrogel, confirming the water's quality (Figure 6e) [41, 42]. Further strategies to achieve even lower residue levels in the desorption process could involve adopting encapsulation layers

[0043] . Reducing the dimensions of hydrogel sorbents significantly enhances kinetics due to the shorter water transport path. Such strategy allows for daily multi-cyclic operations, effectively harnessing atmospheric moisture and greatly elevating the water yield up to 14.19 kg kg”1day”1(Figure 48a-Figure 48b). With the favorable atmospheric water harvesting capabilities and practical viability, the molecularly functionalized biomass hydrogels prove to be effective sorbents for sustainable water production from the atmosphere (Figure 6f and Table 6).

[0358] Discussion. Atmospheric water harvesting technology offers a viable path to support SDG 6, aimed at ensuring the availability and sustainable management of water by 2030. This work employs natural polysaccharides in a two-step molecular functionalization process to develop environmentally responsible sorbents with high water uptake and ease of regeneration. Given that the raw materials can be extracted from abundant and renewable bio-based resources, a sustainable and continuous supply is ensured, reinforcing SDG 12’s commitment to sustainable management and efficient use of natural resources. In this strategy, the interplay between the thermoresponsive and zwitterionic groups is finely tuned to achieve balanced sorption¬ desorption characteristics of the sorbent. Demonstrated with cellulose, starch, and chitosan, which exhibit notable water uptake capacities — 1.32, 0.89, and 1.09 g g”1at 30% relative humidity, respectively, and are capable of desorbing over 90% of absorbed water at a moderate temperature of 60 °C. Moreover, the molecularly functionalized biomass hydrogels demonstrate practical effectiveness in outdoor daily dual-cyclic and multi-cyclic operations, achieving a clean water delivery rate of up to 14.19 kg kg”1day”1. This strategy not only demonstrates its efficiency but also underscores its universality and versatility, potentially expanding the range of raw material sources for sorbent materials, moving beyond the traditional, limited approach of10046-676W01; 8637 YU tailoring specific materials.

[0359] As moving toward scaling production of molecularly functionalized biomass hydrogels for practical implementation, some further improvements can potentially benefit the overall efficiency and sustainability. While this work primarily focuses on demonstrating the universality and intrinsic advantages of the molecular engineering methodology, additional optimizations to the material’s transport properties could potentially improve system performance. For instance, engineering pore hierarchies could further accelerate sorption-desorption kinetics

[0015] , while designing polymer composites could enhance thermal conductivity

[0045] , Additionally, integrating photothermal properties into molecularly functionalized biomass hydrogel sorbents could further enable the utilization of clean energy sources (Figure 51 a-Figure 51c). At the system level, device engineering approaches such as maximizing solar utilization

[0046] , incorporating multi-stage desorption strategies

[0047] , and improving cooling strategies

[0048] , as reported in other studies, could help fully leverage the sorbents’ potential and boost overall performance.

[0360] Parallelly, in pursuit of SDG 12’s objective for responsible production and consumption, adopting green synthesis practices that minimize environmental impacts is crucial. The synthesis of molecularly functionalized biomass hydrogels predominantly occurs in a benign aqueous environment without any strong acid or base residues. While the creation of zwitterionic agents does involve the use of organic solvent, the solvent can be responsibly managed through recycling practices to substantially reduce waste generation (Figure 52a-Figure 52b).

[0361] Additionally, the synthesis protocol demonstrated in this work serves as a proof of concept. By incorporating widely accepted industrial practices, such as enhanced mixing, supercritical CO2-mediated synthesis, closed-loop systems, and reagent recycling, there is considerable potential to optimize the production process. Further refinement of these process parameters could increase the efficiency of biomass functionalization reactions, thus minimizing the use of chemical agents and organic solvents.

[0362] In summary, this study introduces a general strategy to transform sustainable biomass resources into effective atmospheric water harvesting sorbents, primarily supporting SDG 6 and SDG 12, and contributing to other sustainability goals. By adapting existing industrial practices, it is envisioned that molecularly functionalized biomass hydrogels will advance toward practical implementation, offering potential to alleviate global water scarcity challenges in a sustainable and scalable way.

[0363] Methods

[0364] Materials and chemicals. Cellulose, starch, chitosan, NaOH (>98%), propylene oxide10046-676W01; 8637 YU (>99%), butane oxide (99%) and divinyl sulfone (>98%) were sourced from Sigma-Aldrich. Isopropanol (>99%) and 1,2-Dichloroethane (>99%) were obtained from Fisher Scientific. 3-(Dimethylamino)propyl chloride hydrochloride and 1,3-Propanesulfonate were acquired from Ambeed and Oakwood Chemical, respectively.

[0365] Alkylation of polysaccharides. For cellulose, a 5 wt% dispersion in isopropanol was first prepared, followed by the dropwise addition of 2.5 mol / anhydroglucose unit NaOH while stirring. After 2 hours at 40 °C, the alkalized cellulose was filtered under vacuum, washed until a 1:3 weight ratio with NaOH solution was achieved. The isopropanol used was recycled for future alkylation process. Propylene oxide (15-40 mol / anhydroglucose unit) was then introduced, reacting for 3.5 hours at 60 °C. The mixture was neutralized with acetic acid post-reaction, purified and dried to yield hydroxypropyl cellulose.

[0366] For starch and chitosan, starch was dispersed in a pH~13 NaOH solution and alkalized for 2 hours at 40 °C. Chitosan was dissolved in a 7 wt% KOH / 8 wt%> LiOH / 8 wt%> urea solution under stirring with a 2 wt% concentration. Butane oxide was then added (starch: 2-6 mol / anhydroglucose unit, chitosan: 16-28 mol / anhydroglucose unit), and the reaction proceeded for 24 hours at 40 °C for starch and 25 °C for chitosan respectively. The reactions were halted and neutralized with acetic acid, purified, and dried to obtain hydroxybutyl-modified starch and hydroxybutyl -modified chi tosan.

[0367] Zwitterionization of alkylated polysaccharides. Alkylated polysaccharides and 2.5 mol / anhydroglucose unit NaOH were dissolved in water (4 wt%, Solution A). Separately, 2M / anhydroglucose unit zwitterionic agent was dissolved into water to prepare a 50 wt% solution (Solution B). After alkalizing Solution A for 2 hours at 40 °C, Solution B was added drop wise, and the reaction continued for 12 hours at 60 °C. The final solution was neutralized, purified, and dried to produce ZHPC-1, ZHBS-1, and ZHBC-1. For preparation of ZHPC-2, ZHBS-2 and ZHBC-2, the same procedure was followed, using ZHPC-1, ZHBS-1 and ZHBC-1, respectively, as the initial reactants in place of the alkylated polysaccharide. This method was also applied in the preparation of ZHPC-3.

[0368] Synthesis of molecularly functionalized biomass hydrogels. In a typical synthesis, functionalized biomass was dissolved in a NaOH solution (pH ~ 12) at a concentration of 5 wt%. Divinyl sulfone was then added as a crosslinker, followed by thorough mixing and degassing to remove bubbles. The resulting solution was left to stand overnight for gelation, after which the formed gel was freeze-dried to obtain the molecularly functionalized biomass hydrogels.

[0369] Characterization. The molecular structure was elucidated using1H NMR (Agilent MR400 spectrometer) and13C NMR (Bruker Prodigy 500 spectrometer). FTIR spectra were10046-676W01; 8637 YU acquired with a Thermo Mattson Infinity Gold FTIR spectrometer, equipped with a liquid nitrogen-cooled narrow-band mercury cadmium telluride detector and a Ge crystal ATR cell. XRD analysis was performed on a Rigaku Miniflex 600 X-ray Diffractometer. Salt content was determined through thermogravimetric analysis (TGA) (PerkinElmer IGA 4000) under a 25 mi min”1airflow and a heating rate of 10 °C min”1. Ion concentrations in the collected water were quantified by ICP-MS (Agilent 7500ce). SEM imaging (FEI Quanta 650) provided insights into sample morphology. Phase transitions and evaporation profiles were investigated using a differential scanning calorimeter (TA Instrument DSC 250) at a constant scan rate of 2 °C min"1. Water sorption and desorption behaviors were measured with a dynamic vapor sorption instrument (Surface Measurement System DVS Adventure), with samples initially preheated to 90 °C under 0% relative humidity for 60 minutes, then stabilized at 25 °C for 30 minutes.

[0370] Supplementary Information

[0371] 51. Hydroxypropylation of cellulose. Hydroxypropyl cellulose (HPC) is synthesized by reacting alkali cellulose with propylene oxide at elevated temperatures and pressures, a process integral to modifying the physical and chemical properties of cellulose. The initial step involves treating cellulose with an alkaline solution, typically sodium hydroxide, which activates the cellulose by making the hydroxyl groups more reactive. This alkalization is critical for facilitating the subsequent reaction.

[0372] In the core of this reaction, propylene oxide acts as an etherifying agent and undergoes a ring-opening reaction with the activated hydroxyl groups of cellulose. This ring-opening occurs when the oxygen atom in the hydroxyl group nucleophilically attacks the less hindered carbon atom in the epoxide ring of propylene oxide, leading to the opening of the epoxide ring and the formation of a new ether linkage. This substitution predominantly targets the three reactive hydroxyl groups present on each anhydroglucose monomer unit of the cellulose chains.

[0373] Moreover, the secondary hydroxyl group formed in the side chain after the initial reaction remains reactive, allowing further reaction with additional propylene oxide molecules. This can result in the formation of side chains that incorporate more than one mole of propylene oxide, further increasing the degree of substitution. Such reactions extend the cellulose chain and introduce hydroxypropyl groups at various positions along the polymer backbone, thus enhancing the solubility and adaptability of hydroxypropyl cellulose for diverse applications.

[0374] 52. Phase transition mechanism of hydroxypropyl cellulose. The phase transition mechanism of hydroxypropyl cellulose from hydrophilic to hydrophobic involves a series of molecular interactions starting with the weakening of hydrogen bonds between the O-H groups of hydroxypropyl cellulose and water molecules. This leads to the dehydration of these groups,10046-676W01; 8637 YU which then self-assemble to form a network. Concurrently, the methyl and methylene groups in hydroxypropyl cellulose also undergo dehydration. This dehydration, coupled with the selfassembly of O-H groups, drives the hydroxypropyl cellulose molecules to become more hydrophobic. The process is further characterized by the diffusion and aggregation of the hydroxypropyl cellulose chains, which is facilitated by the hydrophobic interactions among the dehydrated groups. This sequence of events results in a significant structural reorganization of hydroxypropyl cellulose, marking its transition from a hydrophilic to a hydrophobic state [A1].

[0375] S3. Tailoring hydroxypropyl substitution level of hydroxypropyl cellulose. As shown in the molecular structure in Figure 9a, the three hydroxyl groups on the cellulose can be repeatedly substituted to have extended side chains that incorporate more than one mole of propylene oxide (PO). Hence, molar substitution (MS) is used herein to denote the average number of propylene oxide molecules added per anhydroglucose unit (AGU) while degree of substitution (DS) is used to denote the average number of cellulosic hydroxyl groups per anhydroglucose unit being substituted in the reaction.

[0376] NMR spectrum is useful in analyzing the structure of hydroxypropyl cellulose since the protons in different chemical environments will give rise to peaks at different magnetic field strengths, and the integrated area from one peak will denote the content of the related proton group, through which molar substitution can be calculated. Figure 9a shows the1H NMR spectrums of the synthesized hydroxypropyl cellulose with different molar substitution in D2O at 25 °C. The peak observed at 1.0 ppm can be ascribed to the methyl groups of the hydroxypropyl (HP) groups in hydroxypropyl cellulose, which are the C-9 protons. Broad peaks observed from 3.0 to 4.0 ppm can be ascribed to the methylene and methine protons excluding the C-l proton, which ascribes to the peak at 4.4 ppm. It occurs because C-l has -O-C-O- bonding while other ring carbons have -C-O- bonding [A2], Therefore, the molar substitution of hydroxypropyl cellulose can be calculated by using the following formula [A3]:

[0377] A 3MS

[0378] B + C ~ 3MS + 7

[0379] where A represents the integrated area from methyl protons; B represents the integrated area from methylene and methine protons excluding the C-l proton; C represents the integrated area from C-l proton in the backbone; MS represents the molar substitution of hydroxypropyl cellulose.

[0380] Although1H NMR spectrum is useful in calculating the molar substitution of hydroxypropyl cellulose, it cannot be used to calculate the degree of substitution due to the serious overlapping of proton signals, especially those assigned to the ring carbons (C-l to C-6). Instead,13C NMR spectrum can differentiate those carbons and thus can be used in the10046-676W01; 8637 YU calculation of degree of substitution. Figure 9b shows the13C NMR spectrum of the synthesized hydroxypropyl cellulose in DMS0-d6 at 25 °C with assigned peaks. Here Cn( n=1, 2, 3, 4, 5, 6) represents the unsubstituted ring carbon, while Cnsrepresents the ring carbon substituted by the hydroxypropyl group (C2s, Css, Ces) or the ring carbon adjacent to the substituted carbon (C1s, C4s). In detail, the occurrence of Ci and Cis are induced by the C-2 position with unsubstituted and substituted hydroxyl groups respectively, while the unsubstituted and substituted C-3 position results in the chemical shift of C4 and C Thus, degree of substitution of hydroxypropyl groups at C-2, C-3, and C-6 positions can be calculated individually by using the following formula:

[0381] DS (C - n) =

[0382]

[0383] Cn+Cns

[0384] where n equals 2, 3, and 6. The total degree of substitution can thus be obtained by the sum of degree of substitution at these three positions.

[0385] In experiments, the molar substitution of hydroxypropyl groups was controlled by using different propylene oxide concentrations, including 15 mol / anhydroglucose unit, 25 mol / anhydroglucose unit, and 40 mol / anhydroglucose unit, where mol / anhydroglucose unit means the mole of propylene oxide added per mole of cellulose anhydroglucose unit. It is calculated that molar substitution increases from 3.9 to 4.8 when propylene oxide concentration increases from 15 mol / anhydroglucose unit to 25 mol / anhydroglucose unit, and then decreases to 1.6 when propylene oxide concentration further increases to 40 mol / anhydroglucose unit. The initial increase trend of molar substitution could be ascribed to the higher possibility that propylene oxide molecules attack the cellulose due to the enhanced propylene oxide concentration. But when propylene oxide concentration increases to exceed a critical value, side reactions like the reaction between propylene oxide and water molecules can be more significant, and thus the molar substitution becomes lower [A4J.

[0386] Molar substitution of hydroxypropyl groups will not only affect the phase transition behavior, which is closely related to the water release performance but also affect the subsequent zwitterionization. Higher molar substitution of hydroxypropyl groups is beneficial to achieve a lower phase transition temperature and thus is favorable for water desorption. However, if the phase transition temperature is too low, the synthesized hydroxypropyl cellulose will conform like ultra-compact globules under the zwitterionization temperature (~60 °C), which can inhibit the contact between the zwitterionization agent and hydroxypropyl cellulose, and thus lower the reaction efficiency. Hence an appropriate value of molar substitution of hydroxypropyl groups should be selected. In this case, the phase transition behavior of the hydroxypropyl cellulose10046-676W01; 8637 YU with molar substitution of 4.8 is too dramatic that it will precipitate during zwitterionization, while the hydroxypropyl cellulose with molar substitution of 1.6 does not have phase transition before 80 °C, which will affect the water desorption. So, the hydroxypropyl cellulose with a molar substitution of 3.9 was selected. The!‘C NMR spectrum was also tested, which is shown in Figure 9b. The degree of substitution (C-2) is calculated to be about 0.2, degree of substitution (C-3) is about 0.3, and degree of substitution (C-6) is about 1, and thus the total degree of substitution is about 1.5. It has a phase transition temperature of about 45 °C, which can facilitate the water release in practical cases, and the phase transition is moderate that a homogeneous reaction system could be formed during zwitterionization.

[0387] S4. Synthesis of zwitterionic agent. The synthesis is based on a reported procedure [A5J.

[0388] 15.8 g of 3-(dimethylamino)propyl chloride hydrochloride was dissolved in 10 mL of water. To this solution, 10 mL of 40% w / v NaOH solution was added dropwise, and the mixture was stirred for 30 minutes. Following this, 3-(dimethylamino)propyl chloride was extracted using a separatory funnel. In the next step, the zwitterionic agent, 3-((3-chloropropyl)dimethylammonio)propane-1-sulfonate, was synthesized by reacting the isolated 3- (dimethylamino)propyl chloride with 18.3 g of 1,3-propanesulfonate in 100 mL. of 1,2-dichloroethane. The reaction was conducted at 70 °C for 6 hours. The resulting product, a white precipitate, was then washed with 1,2-di chloroethane and dried under vacuum. The yield of the synthesis was determined to be 94%.

[0389] The synthesis of 3-((3-chloropropyl)dimethylammonio)propane-l-sulfonate involves the ring-opening reaction of 1,3-propanesulfonate with the tertiary amine, 3-(dimethylamino)propyl chloride. This reaction is characterized by the nucleophilic attack of the nitrogen atom in the tertiary amine on the electrophilic sulfur atom of 1,3-propanesulfonate. The high electron density on the nitrogen atom and the electrophilic nature of the sulfur, enhanced by its adjacent oxygen atoms, facilitate this initial step. Following the nucleophilic attack, the sultone ring opens, leading directly to the formation of the zwitterionic agent.

[0390] S5. NMR result of zwitterionic agent.1H NMR result of zwitterionic agent is shown in Figure 11. The peak observed at 3.54 ppm corresponds to the hydrogens of the methylene groups present in the compound. In the region of 3.39-3.30 ppm, the peaks are attributed to the hydrogens of the methylene groups connected to the nitrogen atoms in the compound. A singlet peak at 2.97 ppm is indicative of the hydrogens of the methyl groups in the compound.

[0391] Additionally, the peak at 2.81 ppm corresponds to the hydrogens of the methylene groups attached to the sulfur atoms. Lastly, the peaks found in the range of 2.17-2.03 ppm are also associated with the hydrogens of the methylene groups in the compound.10046-676W01; 8637 YU S6. Zwiterionization of hydroxypropyl cellulose. The zwi (terionization of hydroxypropyl cellulose is achieved through a reaction with 3-((3-chloropropyl)dimethylammonio)propane-1-sulfonate, utilizing the Williamson etherification mechanism (Figure 12a-Figure 12b). In this process, the oxygen atom in the hydroxyl groups of hydroxypropyl cellulose acts as a nucleophile, targeting the electrophilic carbon bonded to the chloride ion, the leaving group, in the zwitterionic agent. This interaction facilitates the formation of an ether bond and the concurrent release of a chloride ion, thereby attaching the zwitterionic group to the hydroxypropyl cellulose backbone.

[0392] An important consideration in this synthesis is the balance of reaction conditions, especially due to the side reactions of hydrolysis and dimerization of the etherifying agent [A6], These side reactions become increasingly significant and can overshadow the main etherification reaction when the concentration of the zwitterionic agent is raised. Consequently, while increasing the degree of substitution of the zwitterionic group is desirable, simply augmenting the concentration of the zwitterionic agent can lead to undesirable side reactions.

[0393] To address this challenge, a strategy of multiple stages of zwitterionization is employed. This involves conducting the zwitterionization in several steps rather than a single, high-concentration reaction. By applying the zwitterionic agent in controlled, successive stages, it is possible to increase the degree of substitution of the zwitterionic group on hydroxypropyl cellulose effectively, while minimizing the occurrence of side reactions.

[0394] S7. Degree of substitution of zwitterionic group in zwitterionic hydroxypropyl celluloses.1H NMR spectrum is used to analyze the structure of zwitterionic hydroxypropyl cellulose and calculate the degree of substitution of the zwitterionic group (Z-DS), which is defined as the molar ratio of the zwitterionic substituent to anhydroglucose unit of the hydroxypropyl cellulose molecules. Figure 13 shows the

[0395]

[0396] NMR spectrums with assigned peaks of the synthesized hydroxypropyl cellulose and zwitterionic hydroxypropyl cellulose with different times of zwitterionization. Zwitterionic hydroxypropyl cellulose-n (n=l, 2, 3) denotes that the sample undergoes n rounds of zwitterionization, and thus has different degree of substitution of the zwitterionic group. Compared with hydroxypropyl cellulose, there are a couple of newly appearing peaks (a, b, c, d, e, f, g) in1H NMR spectrums of zwitterionic hydroxypropyl celluloses, which can be assigned to the peaks of the zwitterionic agent as described in S5. It indicates that zwitterionic agent is successfully grafted to the hydroxypropyl cellulose. Based on the discussion about the

[0397]

[0398] NMR spectrums of hydroxypropyl cellulose and zwitterionic agent in S3 and S5, the peak at 4.4 ppm is related with the C-l proton in hydroxypropyl cellulose, and the peak at 3.0 ppm is related to the protons of the methyl group in10046-676W01; 8637 YU zwitterionic agent (d position). Hence the degree of substitution of the zwitterionic group can be calculated using the following formula [A5]:

[0399] Id / 6

[0400] Z − DS =

[0401] -i

[0402] where Id represents the integrated area from the methyl group in zwitterionic agent; Ic-i represents the integrated area from C- 1 position in the backbone.

[0403] Thus, it can be calculated that the degree of substitution of the zwitterionic group of ZHPC-1 is about 0.3, degree of substitution of the zwitterionic group of ZHPC-2 is about 0.4, and the degree of substitution of the zwitterionic group of ZHPC-3 is about 0.5.

[0404] S8. Swelling ratios of zwitterionic hydroxypropyl cellulose hydrogels. The swelling ratios of zwitterionic hydroxypropyl cellulose hydrogels are determined by incubation in LiCl solutions of varying concentrations (Figure 14). Consistently across all samples, the swelling ratios increase with lower concentrations and reach a peak at 5 M LiCl solution. Notably, ZHPC-3 exhibits a higher swelling ratio compared to those with lower degree of substitution of zwitterionic groups. This underscores the significant role of zwitterionic moieties in augmenting swellability upon exposure to salt solutions, thereby enhancing salt loading and facilitating water transport during the sorption process.

[0405] S9. Phase transitions of hydroxypropyl cellulose and zwitterionic hydroxypropyl celluloses. Hydroxypropyl cellulose and zwitterionic hydroxypropyl cellulose polymer solutions are utilized to visualize the phase transition at elevated temperatures (Figure 15 -Figure 16). In Figure 15, the first row shows the solutions as transparent at room temperature. Upon heating to their respective lower critical solution temperatures, they turn opaque, a transformation depicted in the second row (Figure 15).

[0406] S10. SEM images of zwitterionic hydroxypropyl cellulose hydrogel. The scanning electron microscopy (SEM) images reveal that the zwitterionic hydroxypropyl cellulose hydrogel possesses a developed pore structure ranging from 10 pm to 100 pm (Figure 17). Such a porous structure is typically advantageous for the atmospheric water harvesting process, as it facilitates vapor and water transport within the network and enhances the hydrogel's water storage capacity. The salt is evenly distributed in the hydrogel skeleton without visible aggregation formed as evidence by the EDX mapping.

[0407] S11. Salt contents of cellulose / LiCl hydrogel. The salt content in cellulose / LiCl hydrogel is -13.3 wt% according to the thermogravimetric analysis (TGA) test (Figure 18). The low salt loading is mainly caused by the unfavorable swelling ratio of pristine cellulose gel in the salt solution.10046-676W01; 8637 YU S12. Salt contents of zwitterionic hydroxypropyl celluloses / LiCl hydrogel. The thermogravimetric analysis reveals the salt content in ZHPC-1, 2, 3 / LiCl hydrogels (Figure 19). Upon heating to 600 °C, the polymer network decomposes completely, leaving behind the mass of salt species. The remaining salt weight in the hydrogels varies, with 40.2 wt% in

[0408] ZHPC-1 / LiCl hydrogel and increasing to 50.2 wt% in ZHPC-3 / LiCl hydrogel, highlighting the effectiveness of zwitterionic groups in augmenting salt loading.

[0409] S13. Water uptake of pristine cellulose. The water uptake of pristine cellulose was evaluated using a dynamic vapor sorption system (Figure 20). It exhibits water uptake capacities of 0.04 g g-1at 15% relative humidity, 0.06 g g-1at 30% relative humidity, and 0.10 g g-1at 60% relative humidity. These results indicate that pristine cellulose demonstrates minimal hygroscopicity, as the strongly interacting intermolecular hydrogen bonds restrict both polymer chain mobility and water transport.

[0410] S14. Water uptake of cellulose / LiCl hydrogel. Compared to pristine cellulose, the cellulose / LiCl hydrogel exhibits a significantly improved water uptake, achieving 0.33 g g-1at 15% relative humidity, 0.52 g g-1at 30% relative humidity, and 0.95 g g-1at 60% relative humidity (Figure 21). This enhanced performance is primarily attributed to the hygroscopic nature of LiCl. Additionally, Li+ions contribute to weakening the intermolecular interactions within cellulose, thereby facilitating water transport [A7], However, the water uptake of the cellulose / LiCl hydrogel is still substantially lower than that of the functionalized cellulose hydrogel.

[0411] S15. Water uptake of hydroxypropyl cellulose / LiCl hydrogel. The hydroxypropyl cellulose / LiCl hydrogel was prepared to validate the effectiveness of zwitterionic groups (Figure 22a-Figure 22b). The hydrogel demonstrated water uptake values of 0.56 and 1.09 g g-1at 30% and 60% relative humidity, respectively, which are significantly lower than those of the zwitterionic hydroxypropyl cellulose hydrogel. Thermogravimetric analysis results revealed that the salt content in the hydroxypropyl cellulose / LiCl hydrogel is approximately 23 wt%. These findings confirm that the introduction of zwitterionic agents substantially enhances the salt loading and storage capacity, attributed to the salting -in effect.

[0412] S16. Sorption isotherm of zwitterionic hydroxypropyl cellulose hydrogel (Figure 23).

[0413] The water uptake observed in this study is higher than previous zwitterionic hydrogel [A8, A9], which is likely attributed to the synergistic factors related to material composition and processing techniques. Firstly, the high salt loading in the hydrogel (exceeding 50 wt%) significantly contributes to the water uptake due to the deliquescence nature of LiCl. Secondly, the freeze-drying process used in this study induces a highly porous structure, as evidenced by10046-676W01; 8637 YU SEM imaging (Figure 16). This porous architecture increases the effective surface area and facilitates the diffusion of water vapor into the hydrogel matrix. Thirdly, the hydrophilicity of the natural polymer backbone plays a pivotal role in enhancing water adsorption. Functional groups such as hydroxyl (-OH) and ether (C-O-C) present in the glucose units exhibit strong affinity for water molecules through hydrogen bonding. The hydration numbers, which quantify the average number of water molecules bound per functional group, further elucidate this behavior. For instance, hydroxyl groups have a hydration number of approximately 2, meaning each hydroxyl group can strongly bind with two water molecules, while ether groups also contribute significantly to hydrophilicity through their lone pairs of electrons [A10], This dense distribution of hydrophilic groups in the molecularly functionalized biomass hydrogel (MFBH) creates a favorable environment for water retention, surpassing the performance of simpler polymer backbones like PDMAPS with fewer active hydration sites.

[0414] S17. Salt storage ability of zwitterionic hydroxypropyl cellulose hydrogel. The hydrogel network acts as an efficient water reservoir, capable of storing absorbed water and simultaneously preventing salt leakage, thereby mitigating potential corrosion issues during its application. To verify the effectiveness of zwitterionic hydroxypropyl cellulose / LiCl in preventing salt leakage, the gel was placed on Kimtech paper both before and after moisture sorption to assess any water extraction from the swollen gel (Figure 24a-Figure 24b). Upon absorbing moisture at approximately 90% relative humidity, the gel exhibited almost no liquid leakage. This observation confirms that zwitterionic hydroxypropyl cellulose / LiCl effectively holds water and salt within the network during sorption, a result of its enhanced swelling in response to the salt solution. This characteristic is particularly advantageous for practical applications where leakage control is crucial.

[0415] S18. Water uptake of zwitterionic hydroxypropyl cellulose / CaCl2hydrogel. By substituting LiCl with the more cost-effective CaCh, a more economical sorbent is obtained. The water uptake of the zwitterionic hydroxypropyl cellulose / CaCh hydrogel, assessed using dynamic vapor sorption testing, is recorded as 0.51 g g-1at 15% relative humidity, 0.92 g g-1at 30% relative humidity, and 1.37 g g-iat 60% relative humidity (Figure 25a). By a thermogravimetric analysis test, the CaCh contents in hydrogel is confirmed to be 66 wt ’ (Figure 25b). The reason for the lower water uptake and higher weight percent of salts in the CaCh version compared to LiCl lies in CaCh’s larger molecular weight. Additionally, the divalent Ca2+ions can act as ionic crosslinkers, potentially restricting chain mobility and thereby affecting water transport within the hydrogel [All],10046-676W01; 8637 YU S19. Desorption performance of zwitterionic hydroxypropyl cellulose hydrogels.

[0416] Desorption performance is assessed using dynamic vapor sorption testing at various temperatures. As indicated in Figure 26a, the equilibrium water desorption amount for ZHPC-1 / LiCl hydrogel decreases from 90% to 85% in ZHPC-3 / LiCl hydrogel at 50 °C, while at 60 °C, both hydrogels desorb nearly the same amount of water. This variation is primarily due to the differences in hydrophilicity-to-hydrophobicity transition temperatures. ZHPC-1 undergoes a more complete transition at 50 °C, thereby facilitating greater water release.

[0417] S20. Indoor water collection device (Figure 27). In the described experiment, a gel film is placed on a controllable heat plate, adjusted by an external power source. To facilitate the efficient descent of water droplets along the collection channel, the condensing surface is angled at 45°. To enhance water collection, heating elements are installed on adjacent walls, slightly raising their temperatures to direct condensation to the desired cooler surface. In conditions of low ambient temperature, which favor condensation, the use of vertical heating elements may be unnecessary. Temperature monitoring and adjustment are conducted through thermocouples attached to the condensing surface and the reverse side of the heating plates. For water collection experiments, the assembly is sealed with a rubber gasket and steel clips to ensure integrity.

[0418] S21. Homemade water vapor sorption measurement setup. In summary, the homemade vapor sorption system comprises three main components: a relative humidity (RH) controller, a sorption testing chamber, and a hygrometer (Figure 28a-Figure 28b). To create airflows with specific relative humidity levels, supersaturated salt solutions are utilized. Dehydrated airflow is introduced into these solutions, typically using supersaturated LiCl and CH3CO2K and NaBr for generating -15%, 30%, and 60% relative humidity conditions, respectively. The testing chamber is securely sealed with a rubber ring, and a hygrometer is employed to continuously monitor the relative humidity and temperature inside the chamber.

[0419] S22. Atmospheric water harvesting performance comparison with reported cellulose-based sorbent. Atmospheric water harvesting performance comparison with reported cellulose- based sorbent is summarized in Table 1.10046-676W01; 8637 YU Table 1. Summary of water sorption performance of reported cellulose-based sorbents Materials Water uptake Ref.

[0420] 0.06 g / g@ 15% RH

[0421] cellulose fabric 0.09 g / g@30% RH [A12]

[0422] 0.31 g / g@60% RH

[0423] 0.49 g / g@25% RH

[0424] cellulose / PPy-Cl / E-CoCl2[A 13]

[0425] 1.07 g / g@65% RH

[0426] 0.73 g / g@33% RH

[0427] cellulose nanofiber / LiCl [A14]

[0428] 1.15 g / g@57% RH

[0429] 0.76 g / g@28% RH

[0430] nanofibrillated cellulose / LiCl [A15]

[0431] 1.13 g / g@65% RH

[0432] cellulose fabric / LiCl 0.3 g / g@ 30% RH [Al 6]

[0433] 0.9 g / g@23% RH

[0434] nanofibrillated cellulose / LiCl [A17]

[0435] 2.17 g / g@60% RH

[0436] 0.77 g / g@ 15% RH

[0437] cellulose nanocrystals / poly(acrylic acid) / LiCl 1.27 g / g@30% RH [A 18]

[0438] 2.29 g / g@60% RH

[0439] 0.5 g / g@ 15%RH

[0440] hydroxypropyl cellulose / LiCl [A19]

[0441] 0.8 g / g@30% RH

[0442] 0.45 g / g@30% RH PNIPAM / hydroxypropyl cellulose / E-LiCl 0.9 g / g@50% RH [A20]

[0443] 1.46 g / g@70%RH

[0444] 0.46 g / g@20% RH

[0445] corn stalk / LiCl 0.82 g / g@40% RH [A21J

[0446] 1.2 g / g@60% RH

[0447] 0.64 g / g@ 15%RH

[0448] KGM / hydroxypropyl cellulose / LiCl 0.96 g / g@30% RH [A22]

[0449] 1.53 g / g@60% RH

[0450] 0.81 g / g@40% RH

[0451] bacterial cellulose / CNT / loofah / CNT [A23]

[0452] 1.12 g / g@60% RH

[0453] 0.85 g / g@15% RH

[0454] zwitterionic hydroxypropyl cellulose / LiCl 1.32 g / g@30% RH This work

[0455]

[0456] 2.18 g / g@60% RH

[0457] S23. Tuning the lower critical solution temperatures of hydroxybutyl-modified starch.

[0458] Hydroxybutyl-modified starch is prepared by reacting starch with butane oxide (BO).

[0459] Hydroxybutyl-niodified starch with different molar substitution of hydroxybutyl (HB) groups and different phase transition temperatures can be obtained by using different butane oxide concentrations. Figure 29 shows the

[0460]

[0461] NMR spectrums of the synthesized hydroxybutyl- modified starch under butane oxide concentrations of 2 mol / anhydroglucose unit, 4 mol / anhydroglucose unit, and 6 mol / anhydroglucose unit, respectively. The singlet observed at10046-676W01; 8637 YU 0.75 ppm and the doublet observed at 1.20-1.44 ppm can be ascribed to the methyl group and methylene groups in the hydroxybutyl group respectively. The broad peak observed from 3.17 to 3.86 ppm can be ascribed to the methylene and methine protons excluding the C-l proton. The multiple peaks at 5.17-5.65 ppm are ascribed to the C-l proton, while such split can be explained by the two different kinds of C-l protons corresponding to the internal a- 1,4 and a- 1,6 linkages respectively [A24], Therefore, the molar substitution of hydroxybutyl-modified starch can be calculated by using the following formula [A2 J:

[0462] lCHJ3

[0463] MS =

[0464]

[0465] I,

[0466] where ICHS represents the integrated area from the methyl group in the hydroxybutyl group; Ic-i represents the integrated area from C-l position in the backbone.

[0467] Thus, it can be calculated that the molar substitution of hydroxybutyl-modified starch with 2 mol / anhydroglucose unit butane oxide concentration is about 0.28, the molar substitution of hydroxybutyl-modified starch with 4 mol / anhydroglucose unit butane oxide concentration is about 0.52, and the molar substitution of hydroxybutyl-modified starch with 6 mol / anhydroglucose unit butane oxide concentration is about 1.36. Correspondingly, their phase transition temperatures are 72 °C, 47 °C, and 37 °C, as shown in Figure 30.

[0468] S24. Degree of substitution of zwitterionic group in zwitterionized hydroxybutyl-modified starches. The calculation of degree of substitution of zwitterionic group (Z-DS) in zwitterionized hydroxybutyl-modified starch is quite similar' to what was done in the cellulose system, as explained in detail in S7. Figure 31 shows the1H NMR spectrums with assigned peaks of the hydroxybutyl-modified starch, and ZHBS-1, ZHBS-2 with one and two rounds of zwitterionization respectively. The newly appearing peaks (denoted as a-g) in zwitterionized hydroxybutyl-modified starch compared with hydroxybutyl-modified starch can be ascribed to the grafted zwitterionic agent. The peak at 3.1 ppm is related to the protons of the methyl group in zwitterionic agent (d position), while the peaks at 5.17-5.65 ppm are related to the C-1 position in the backbone. Hence the degree of substitution of the zwitterionic group can be calculated using the following formula:

[0469] / d / 6

[0470] Z - D S =

[0471]

[0472] Ic-i

[0473] where Id represents the integrated area from the methyl group in the zwitterionic agent; Ic-i represents the integrated area from C-l position in tlie backbone.

[0474] Thus, it can be calculated that the degree of substitution of the zwitterionic group of ZHBS-1 is about 0.2, and the degree of substitution of the zwitterionic group of ZHBS-2 is about 0.35.10046-676W01; 8637 YU S25. SEM images of zwitterionized hydroxybutyl-modified starch hydrogel. SEM images of zwitterionized hydroxybutyl-modified starch hydrogel are shown in Figure 32.

[0475] S26. Water uptake of pristine starch (Figure 33). The water uptake of pristine starch was evaluated using a dynamic vapor sorption system. It exhibits water uptake capacities of 0.07 g g”1at 15% relative humidity, 0.10 g g”1at 30% relative humidity, and 0.15 g g-1at 60% relative humidity.

[0476] S27. Desorption performance of zwitterionized hydroxybutyl-modified starch / LiCl hydrogel. Desorption performance of zwitterionized hydroxybutyl-modified starch / LiCl hydrogel is shown in Figure 34.

[0477] S28, Cycling performance of zwitterionized hydroxybutyl-modified starch / LiCl hydrogel. As shown in Figure 35, the sorption-desorption curves almost overlap before and after 20 cycling operations. This suggests that the atmospheric water harvesting properties do not change during the cycling test.

[0478] S29. Tuning the lower critical solution temperatures of hydroxybutyl-modified chitosans. Hydroxybutyl-modified chitosan can be obtained through the homogeneous reaction between chitosan and butane oxide (BO). Through changing butane oxide concentration, hydroxybutyl-modified chitosan with different molar substitution of hydroxybutyl groups and different phase transition temperatures can be obtained. Figure 36 shows the1H NMR spectrums of the synthesized hydroxybutyl-modified chitosan under butane oxide concentrations of 16 mol / anhydroglucose unit, 20 mol / anhydroglucose unit, and 28 mol / anhydroglucose unit, respectively. Similar to the discussion in S23, the peaks at 0.77 ppm and at 1.20-1.45 ppm are related to the methyl group and methylene groups in the hydroxybutyl group respectively. Broad peak observed from 3.20 ppm to 3.97 ppm and from 2.31 ppm to 2.88 ppm is related to the methylene and methine protons in the backbone excluding the C-l proton, which is related to the peak at 4.35 ppm. The peak at 1.90 ppm is related to the protons of N-acetyl glucosamine. Therefore, the molar substitution of hydroxybutyl-modified chitosan can be calculated using the following formula [A26]:

[0479] ^CH

[0480] MS = — —3 / 3

[0481]

[0482] ‘c-i

[0483] where ICH3represents the integrated area from the methyl group in the hydroxybutyl group; Ic-i represents the integrated area from C-l position in the backbone.

[0484] Thus, it can be calculated that the molar substitution of hydroxybutyl-modified chitosan with butane oxide concentration 16 mol / anhydroglucose unit is about 0.83, the molar substitution of hydroxybutyl-modified starch with butane oxide concentration 2010046-676W01; 8637 YU mol / anhydroglucose unit is about 1.05, and the molar substitution of hydroxy butyl -modified starch with butane oxide concentration 28 mol / anhydroglucose unit is about 1.53.

[0485] Correspondingly, their phase transition temperatures are 62 °C, 45 °C, and 35 °C based on Figure 37.

[0486] S30. SEM images of zwiterionic hydroxybutyl-modified chitosan hydrogel. SEM images of zwitterionic hydroxybutyl-modified chitosan hydrogel are shown in Figure 38.

[0487] 531. Water uptake of pristine chitosan (Figure 39). The water uptake of pristine chitosan was evaluated using a dynamic vapor sorption system. It exhibits water uptake capacities of 0.06 g g-1at 15% relative humidity, 0.10 g g-1at 30% relative humidity, and 0.16 g g-1at 60% relative humidity.

[0488] 532. Desorption performance of zwitterionic hydroxybutyl-modified chitosan / LiCl hydrogel. Desorption performance of zwitterionic hydroxybutyl-modified chitosan / LiCl hydrogel is shown in Figure 40.

[0489] 533. Cycling performance of zwitterionic hydroxybutyl-modified chitosan / LiCl hydrogel. As shown in Figure 41, the sorption-desorption curves almost overlap before and after 20 cycling operations. This suggests that the atmospheric water harvesting properties do not change during the cycling test.

[0490] 534. Interpenetrating network (IPN)ILiCl hydrogels for starch and chitosan system.

[0491] While the zwitterionized hydroxybutyl-modified starch / zwitterionic hydroxybutyl-modified chitosan- 1 / LiCl hydrogels demonstrate improved water uptake relative to their pristine counterparts, their performance in water uptake and desorption can be further optimized by incorporating interpenetrating polymer network (IPN) hydrogels. By integrating HBS__6 mol / anhydroglucose unit butane oxide and HBC 28 mol / anhydroglucose unit butane oxide into the zwitterionized hydroxybutyl-modified starch / ZHBC-2 solution, respectively, and subsequently undergoing a crosslinking process followed by salt impregnation, interpenetrating polymer network hydrogels are formed. The inclusion of HBS_6 mol / anhydroglucose unit butane oxide and HBC_28 mol / anhydroglucose unit butane oxide, characterized by a lower LCST (lower critical solution temperature) as previously discussed, aims to enhance water desorption efficiency. Additionally, zwitterionized hydroxybutyl-modified starch / ZHBC-2 serves as a structural framework within the hydrogel, maintaining the enhanced swelling properties and thereby augmenting water uptake.

[0492] As evidenced in Figure 42a and Figure 43a, the interpenetrating polymer network hydrogels exhibit water uptake values that are intermediate between those of the first and second zwitterionized hydrogels, achieving 1.16 g g-1for the starch system and 1.29 g g-1for the10046-676W01; 8637 YU chitosan system. Moreover, the interpenetrating polymer network hydrogels show superior desorption performance compared to the single-network hydrogels, with both systems capable of desorbing over 90% of the absorbed water, as shown in Figure 42b and Figure 43b.

[0493] 535. Structure comparison ofZHPC-3 synthesized in large and small batches.

[0494] Structure comparison of ZHPC-3 synthesized in large and small batches is shown in Figure 44.

[0495] 536. Water uptake comparison between small and large zwitterionic hydroxypropyl cellulose / LiCl hydrogels. Water uptake comparison between small and large zwitterionic hydroxypropyl cellulose / LiCl hydrogels is shown in Figure 45.

[0496] 537. Techno-economic analysis.

[0497] To assess the practical applicability of this system, a techno-economic analysis was conducted to explore the relationship between the water price (Pw,

[0498]

[0499] produced by this system and its lifetime (tjjfe, year) as shown in Figure 46. The water price is related with the system cost and the annual water production (Lyear). Since an electric heating plate is involved, operational cost (Co) which comes from the electricity consumption should be considered as part of the system cost besides the cost of sorbent and device component (Ct) as summarized in Table 2 and Table 3, and maintenance fee (Cm). The operational cost is calculated based on the electricity consumption per liter of water produced (EC) determined from the outdoor test (Figure 6c), annual water production, and the unit price of electricity (Pe) as shown in the following formulas:

[0500] „ „rheating ‘-desorption 301V * 40h

[0501] EC = 1.65 kWh / L

[0502] ‘-’water O. / 26n

[0503] 1.65kWh 53L 0.041$

[0504] Co= EC * Lyear* Pe= 1.65kWh / L * 53L / year * 0.041$ / kWh = 3.59 $ / year

[0505]

[0506] year kWh

[0507] where Seating is the power of the heating plate, tdesorption is the total desorption duration, and Lwater is the water produced during that outdoor test.

[0508] Thus, the water price can be calculated by the following formula:

[0509] _ Q + (Cm+ Co) * tufe

[0510]

[0511] j-year Htfe

[0512] By comparing the water price with the bottled water price in USA (0.335 $ / L) [A27], the payback time for the system is estimated to be about 0.88 years.10046-676W01; 8637 YU Table 2. The cost of chemicals in ZHPC-3

[0513] Chemicals Price ($ / kg) Cost in ZHPC-3 gel ($ / kg) Cellulose 0.56 0.19

[0514] 1,3-Propanesultone 1 3.27

[0515] Sodium hydroxide 0.6 0.64

[0516] 3-Chloro-N, N-dimethylpropan- 1 - 1 2.83

[0517] amine HC1

[0518] Propylene oxide 1.83 5.65

[0519] Lithium chloride 1.2 0.6

[0520]

[0521] Total 13.18

[0522] Price obtained from industry source.

[0523] In the typical synthesis of molecularly functionalized cellulose (ZHPC), the primary organic solvents--- 1,2-dichloroethane (DCE) and isopropanol (IPA)——serve as inert reaction media, facilitating the zwitterionic and alkylation steps, respectively. Both solvents are recycled within the synthesis protocol, as detailed in Methods and Section S4. This recycling minimizes solvent consumption, significantly reducing associated costs and environmental impact.

[0524] Consequently, the cost contribution of these solvents was excluded from the analysis.

[0525] Sodium hydroxide (NaOH) is employed in both the alkylation and zwitterionization processes as a reactant and catalyst. Post-reaction, the alkaline solution is neutralized to mitigate environmental impact. While NaOH recycling is not feasible at the current lab scale due to equipment constraints, industrial processes commonly incorporate effective recycling methods such as diffusion dialysis and crystallization, recovering up to 80% of the NaOH used [A28]. Additionally, advanced techniques like ion-exchange systems and membrane electrolysis offer further avenues for reagent recovery and reuse.

[0526] To enhance sustainability and reduce reagent consumption, adopting industrial practices, such as enhanced mixing technologies, are envisioned. High-shear mixing, ultrasonic mixing, and static mixers, widely used in polymer and chemical industries, can improve reaction kinetics and mass transfer, reducing the consumption of petrochemical reagents. By incorporating these industrial practices into the synthesis protocol, the process can become significantly more efficient and environmentally sustainable. These advancements align with the vision for scaling up the production of atmospheric water harvesting sorbent materials, making them both cost-effective and sustainable for practical applications.10046-676W01; 8637 YU Table 3. The cost of components in device

[0527] Maintenance fee Materials Cost ($) Lifespan (year)

[0528] ($ / year)

[0529] Acrylic glass 2.967 10 0.2967

[0530] Heating plate 5.714 5 1.1428

[0531] Acrylic glue 0.11 10 0.011

[0532] Sorbent 1.32 1 1.32

[0533]

[0534] Total 2.77

[0535] Table 4. Techno-economic analysis of the whole system

[0536] Variables Meaning Unit Value Notes

[0537] Total cost of Ct is estimated based on

[0538] ct$ 10.11

[0539] the system sorbent and device cost.

[0540] Cm is estimated based on the Maintenance

[0541] Cm $ / year 2.77 price of parts and the relevant fee

[0542] lifetime.

[0543] Co is estimated based on the Operational

[0544] Co $ / year 3.59 electricity consumption and cost

[0545] the electricity cost in Texas.

[0546] Lyettr is estimated based on the Annual water

[0547] Lyear L / year 53 water production in outdoor

[0548] productivity

[0549]

[0550] tests.

[0551] S38. Multi-cyclic operation for practical water production. Thin zwitterionic hydroxypropyl cellulose films are prepared by casting and gelation (Figure 47a-Figure 47b), with three films strategically placed within the harvester chamber, as depicted in Figure 48a. The reduced thickness significantly enhances kinetics by shortening the liquid transport pathway [A19, A29], Furthermore, the larger pores formed due to the slower cooling rate, compared to the bulk gel, help reduce vapor transport resistance. Multicyclic operations over 24 hours showcases the improved water delivery capability, with a cycle comprising a 2-hour sorption stage followed by a 1-hour desorption stage. This setup enables eight cycles in one day, resulting in the production rate up to 14.19 kg kg-1day-1, markedly surpassing the 1.44 kg kg-1day-1achieved with bulk gels. These results underscore the zwitterionic hydroxypropyl cellulose hydrogel’s vast practical potential through sorbent configuration design. The zwitterionized hydroxybutyl-modified starch and zwitterionic hydroxy butyl -modified chitosan gel films were also tested with similar approaches. The results validate their practical water extraction ability.

[0552] S39. Water harvesting in arid climates. Water harvesting in arid climates results are shown in Figure 50a-Figure 50b and Table 5.10046-676W01; 8637 YU Table 5. Comparison of the water harvesting capability in arid climates.

[0553] Nighttime Daytime

[0554] Daily water yield per relative relative

[0555] sorbent mass (g g1day4) humidity humidity

[0556] Nat Commun 13, 5406 (2022) 38%-65% 15%-65% 1.09

[0557] Energy 293, 130749 (2024) 35%-82% 25%-79% 0.26

[0558] ACS Cent. Sei. 5, 1699-1706 (2019) 30%-53% 14%-30% 0.7

[0559] Nat Water 1, 626-634 (2023) 10%-20% 5%-18% 0.114

[0560] Nat Commun 9, 1191 (2018) 26%-34% 12%-16% 0.19

[0561] Energy Environ. Sci., 14, 5979-5994

[0562] N / A 42%-70% 1.05

[0563] (2021)

[0564] Nat Commun 15, 7678 (2024) N / A 24%-33% 1.73

[0565] Device 2, 100441 (2024) N / A 19%-55% 1.66

[0566] 68%-90% 14%-30% 1.6

[0567] Dual-cyclic

[0568] -30% 0.78

[0569] This work

[0570] 32%-58% 28%-54% 8.3

[0571] Multicyclic

[0572]

[0573] -30% 7.12

[0574] S40. Comparison of different materials for atmospheric water harvesting. The zwiterionic hydroxypropyl cellulose hydrogel is compared with hygroscopic salts, MOFs, and synthetic polymer-based hydrogels in terms of water uptake, energetic ease of regeneration, cycling stability, material sustainability, and processibility, which are key parameters to evaluate their potential for practical atmospheric water harvesting applications. Desorption is a key stage where the absorbed water will be desorbed through heating. Sorbents with lower desorption temperature is energetically easier to release the absorbed water. In this case, the temperature to desorb 80% water uptake was used to measure the energetic ease of regeneration. Furthermore, sorbent is considered to have good sustainability when it can be produced in necessary quantities without depleting non-renewable resources and without disrupting the established steady-state equilibrium of the environment and key natural resource system (http: / / sustain.rutgers.edu / what_are_sustainable_niaterials). To evaluate the processibility, three factors are considered, which are ease of synthesis, scalability, and cost-effectiveness.

[0575] Hygroscopic salts show high water uptake, but also require high temperature to release most of water they absorbed [Al 6, A30, A31], The sluggish kinetics due to the passivation layer formed during deliquesce can further undermine their potential for practical applications [A32, A33J. Hygroscopic salts are generally considered to have lower processability due to their difficulty in shaping and the risk of device corrosion caused by uncontrolled liquefaction.

[0576] Therefore, the processability is rated as "medium." However, the production of hygroscopic salts, such as CaCb, is a well-established industrial process, and these salts can be widely sourced from industrial by-products or minerals, making their sustainability rating "good".10046-676W01; 8637 YU MOFs are a class of promising sorbents for atmospheric water harvesting possessing merits of low desorption temperature, long-term cyclability, ease of synthesis, and potentially low cost [ A34-A37], However, there is still potential to further enhance the water uptake capacity of MOFs. Additionally, recent attention has been drawn to toxicity assessments and green synthesis methods [A38, A39]. While some MOFs are derived from non-toxic reagents, given the diversity within the MOF family, their overall sustainability is rated as “medium”.

[0577] Synthetic hydrogels are superior in water uptake performance. To release most of the absorbed water, some of them require high temperature, while the thermoresponsive polymer-based hydrogels can be energetically easier to desorb water, and thus have a better performance [A40, A41J. With comprehensive consideration, it is given a 4. Synthetic polymers are not advantageous in terms of sustainability since many of the commonly used polymers are derived from petroleum. Besides, polymers suffering from salting-out effect (PNIPAM, etc.) typically have poor swelling ability, which may risk salt leakage under high relative humidity, and thus demonstrate a compromised cycling stability [A40, A42-A44], which reduce the overall rating of “cycling stability” to “medium”. Although incorporating zwitterionic polymer (PDMAPS, etc.) has been proved to be an efficient method to solve the problem, the monomer synthesis is relatively complicated and expensive with special gas environment and elongated reaction time in organic solvent required [A45-A47],

[0578] The MFHBs, featured by the co-existing of thermoresponsive group and zwitterionic group, demonstrates superior atmospheric water harvesting performance. Besides, the major raw materials (cellulose, starch, or chitosan) are abundant in nature, and the externally sourced chemical groups only account for starting from 33 wt%, showing sustainability advantages. Moreover, the fabrication of molecularly functionalized biomass hydrogels doesn’t involve special environment requirement, complicated reaction, high energy consumption, or expensive equipment and chemicals, making it advantageous in terms of processibility.10046-676W01; 8637 YU Table 6. Rating of hydrogel sorbents

[0579] molecularly

[0580] functionalized

[0581] Hygroscopic salt MOFs Synthetic hydrogels biomass

[0582] hydrogels

[0583] Water uptake 4 5 2 4

[0584] Energetic ease

[0585] 5 1 5 4 of regeneration

[0586] Cycling

[0587] Good Good Good Medium

[0588] stability

[0589] Material

[0590] Good Good Medium Medium

[0591] sustainability

[0592]

[0593] Processibility Good Medium Good Medium

[0594] *Good represents Score 5, and Medium represents Score 4.

[0595] Table 7. Evaluation matrix of water uptake

[0596] Water uptake at 30% relative

[0597] Score

[0598] humidity (g g-1)

[0599] 1 <0.5

[0600] 2 0.5 -0.8

[0601] 3 0.8-1.1

[0602] 4 1.1-1.4

[0603]

[0604] 5 >1.4

[0605] Table 8. Evaluation matrix of desorption temperature

[0606] Score Temperature to desorb 80% water uptake 1 >90

[0607] 2 80-90

[0608] 3 70-80

[0609] 4 60-70

[0610]

[0611] 5 <60

[0612] S41. Photothermal zwitterionic hydroxypropyl cellulose. Photothermal zwitterionic hydroxypropyl cellulose (P-ZHPC) hydrogels were prepared by incorporating active carbon into the precursor solution, in addition to the standard procedure described for zwitterionic hydroxypropyl cellulose in the Methods section. As shown in Figure 51a, photothermal zwitterionic hydroxypropyl cellulose exhibits high absorbance across the solar spectrum. Under 0.5, 1, and 1.5 sun radiation, the sorbents reach temperatures of 48°C, 60°C, and 69°C, respectively, demonstrating the feasibility of utilizing sunlight for photothermal heating.

[0613] Importantly, photothermal zwitterionic hydroxypropyl cellulose shows only a slight decrease in10046-676W01; 8637 YU water uptake compared to zwitterionic hydroxypropyl cellulose (Figure 51b), which is likely due to the addition of non-hygroscopic active carbon.

[0614] S42. Recycling of dichloro ethane in zwitterionic agent synthesis. Dichloroethane (DCE) is utilized as the solvent in the synthesis of zwitterionic agents due to its chemical inertness. Despite its widespread use across various industrial applications, such as pharmaceuticals and agrochemicals, managing dichloroethane responsibly is essential for adhering to green synthesis principles and achieving the broader SDG 12 goal of substantially reducing waste generation through prevention, reduction, recycling and reuse. Investigation into the recycling effects of dichloroethane on zwitterionic agent synthesis reveals that the yield remains stable at approximately 94% after five recycling cycles (Figure 52a). The consistency in molecular structure of the synthesized agent is maintained, as evidenced by consistent *H NMR spectra across cycles (Figure 52b). This stability is likely due to the product's insolubility in dichloroethane, which minimally affects the solvent’s properties. These findings underscore the synthesis process’s sustainability for molecularly functionalized biomass hydrogels.

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[0704] [A44] P. A. Kallenberger et al. Commun. Chem. 2018, 1, 28.

[0705] [A45] W. Guan et al. Proc. Natl. Acad. of Sci. 2023, 120, e2308969120.

[0706] [A46] P. Starck et al. Langmuir 2007, 23, 7587-7593.

[0707] [A47] D. Kratzer et al. Eur. J. Org. Chem. 2014, 2014, 8064-8071.

[0708] Example 4 - Molecularly functionalized biomass hydrogels for sustainable atmospheric water harvesting

[0709] Background. Sorption-based atmospheric water harvesting (SAWH) is illustrated schematically in Figure 53. Hydrogel sorbents can be used for SAWH due to the properties illustrated schematically in Figure 54.

[0710] However, traditional hydrogel sorbents are derived from petrochemicals and therefore represent certain concerns related to materials sustainability (Figure 55). To address this, biomass feedstock represent a readily available source of biomass polymers, but they typically have drawbacks such as poor hydrability, poor hygoscopicity, poor processability, etc. (Figure 56).

[0711] Polysaccharides represent a promising sorbent platform with extensive functionalization opportunities (Figure 57). Desorption efficiency can be enhanced via thermoresponsive biomass (Figure 58). Water uptake can be enhanced via zwitterionization (Figure 59).

[0712] Disclosed herein in a universal strategy for molecularly functionalized biomass hydrogels (MFBHs ) (Figure 60).

[0713] Results. Molecularly functionalized cellulose was prepared (Figure 61) and characterized (Figure 62a-Figure 62c). Water update properties of the cellulose system are shown in Figure 63a-Figure 63b. Water release behavior of the cellulose system are shown in Figure 64a-Figure 64c.

[0714] Similarly, molecularly functionalized starch and chitosan were prepared and characterized (Figure 65a-Figure 65b). Water uptake properties of the molecularly functionalized starch and chitosan are shown in Figure 66a-Figure 66b. Water release properties of the molecularly functionalized starch and chitosan are shown in Figure 67a-Figure 67d.10046-676W01; 8637 YU An outdoor atmospheric water harvesting test was performed, as shown in Figure 68a- Figure 68e.

[0715] Results of the outdoor atmospheric water harvesting test with gel thin films are shown in Figure 69a-Figure 69b.

[0716] Example 5 - From Scraps to Sips: Everyday Biomass produces Drinking Water from Thin Air

[0717] Discarded food scraps, stray branches, seashells and many other natural materials are key ingredients in a new system that can pull drinkable water out of thin air. This new “molecularly functionalized biomass hydrogels” system can convert a wide range of natural products into sorbents, materials that absorb liquids. By combining these sorbents with mild heat, galls of drinkable water can be harvested out of the atmosphere, even in dry conditions.

[0718] With this breakthrough, a universal molecular engineering strategy has been developed that allows diverse natural materials to be transformed into high-efficiency sorbents. This opens an entirely new way to think about sustainable water collection, marking a big step towards practical water harvesting systems for households and small community scale.

[0719] In field tests, 14.19 liters (3.75 gallons) ofclean water were generated per kilogram of sorbent daily. This exceeds most state-of-the-art sorbents, which have demonstrated practical performance of typically 1-5 L / kg / day. The high performance of the sorbents described herein was achieved by designing the sorbent film configuration and applying multi-cyclic operations.

[0720] This system represents a new way of designing sorbents. Instead of the traditional “select-and-combine” approach, which required picking specific materials for specific functions, this general molecular strategy makes it possible to turn almost any biomass into an efficient water harvester.

[0721] Unlike existing synthetic sorbents, which use petrochemicals and generally require high energy inputs, the biomass-based hydrogels described herein are biodegradable, scalable, and require minimal energy to release water. The secret lies in a two-step molecular engineering process that imparts hygroscopic properties and thermoresponsive behavior to any biomass-based polysaccharide, such as cellulose, starch, or chitosan.

[0722] At the end of the day, clean water access should be simple, sustainable, and scalable. The materials described herein provide a way to tap into nature’s most abundant resources and make water from air - anytime, anywhere.

[0723] The technology described herein is part of a quest to develop solutions for people lacking access to clean drinking water. Previously, water-generating hydrogels have been developed and10046-676W01; 8637 YU adapted for the driest conditions. Recently, an injectable water filtration system was created, and hydrogel technology has been applied to farming.

[0724] Scaling production and designing real-world device systems for commercialization, including portable water harvesters, self-sustaining irrigation systems, and emergency drinking water devices, are being worked on. Since the beginning, a focus has been on scalability and the ability to translate this technology into solutions that can help people around the world.

[0725] The biggest challenge in sustainable water harvesting is developing a solution that scales up efficiently and remains practical outside the lab. Since this hydrogel can be fabricated from widely available biomass and operates with minimal energy input, it has strong potential for large-scale production and deployment in off-grid communities, emergency relief efforts, and decentralized water systems.

[0726] EXEMPLARY ASPECTS

[0727] In view of the described compositions, devices, systems, and methods, herein below are described certain more particularly described aspects of the inventions. The particularly recited aspects should not, however, be interpreted to have any limiting effect on any different claims containing different or more general teachings described herein or that the “particular” aspects are somehow limited in some way other than the inherent meanings of the language and formulas literally used therein.

[0728] Example 1: A molecularly functionalized biomass-derived hydrogel, comprising a polysaccharide derived from a biomass functionalized with a plurality of thermoresponsive alkylations and a plurality of zwitterionic functionalizations.

[0729] Example 2: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly example 1, wherein the polysaccharide is derived from a sustainable biomass feedstock.

[0730] Example 3: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly example 1 or example 2, wherein the polysaccharide comprises a carbohydrate.

[0731] Example 4: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-3, wherein the polysaccharide comprises a native carbohydrate, a modified carbohydrate, a derivative of a carbohydrate, a breakdown product (e.g., metabolite) of a carbohydrate, or a combination thereof.

[0732] Example 5: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-4, wherein the polysaccharide comprises cellulose, hemicelluloses, starch, pectins, chitin, chitosan, gums / galactomannans,10046-676W01; 8637 YU alginates / agar / carrageenans; derivatives thereof; mixtures thereof; and / or breakdown products (e.g., metabolites) thereof.

[0733] Example 6: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-5, wherein the polysaccharide comprises cellulose, starch, chitosan, or a combination thereof.

[0734] Example 7: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-6, wherein the polysaccharide comprises cellulose.

[0735] Example 8: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-7, wherein the polysaccharide comprises starch.

[0736] Example 9: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-8, wherein the polysaccharide comprises chitosan.

[0737] Example 10: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-9, wherein the plurality of thermoresponsive alkylations disrupt the hydrogen bond network of the polysaccharide to facilitate further modifications, and balance hydrophobic and hydrophilic elements to confer thermoresponsiveness, enabling the hydrophobic interaction at elevated temperatures to ease the release of water molecules.

[0738] Example 11: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-10, wherein the plurality of thermoresponsive alkylations comprise N-alkyl amide motifs (for example, N-isopropyl, N-ethyl, N-propyl, N-cyclopropyl, and N, N-dialkyl amide functionalities), cyclic amide (lactam) motifs (for example, pyrrolidone and caprolactam functionalities), oligo(ethylene glycol) motifs (for example, pendant OEG chains of tunable ethylene-oxide length and end group), hydroxyalkyl motifs (for example, hydroxypropyl and hydroxybutyl functionalities), tertiary amine motifs (for example, dialkyl aminoalkyl functionalities), or a combination thereof.

[0739] Example 12: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-11, wherein the plurality of thermoresponsive alkylations comprise hydroxypropyl groups, hydroxybutyl groups, or a combination thereof.

[0740] Example 13: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-12, wherein the polysaccharide comprises cellulose and the plurality of thermoresponsive alkylations comprise hydroxypropyl groups.

[0741] Example 14: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-13, wherein the polysaccharide comprises starch and the plurality of thermoresponsive alkylations comprise hydroxybutyl groups.

[0742] Example 15: The molecularly functionalized biomass-derived hydrogel of any example10046-676W01; 8637 YU herein, particularly examples 1-14, wherein the polysaccharide comprises chitosan and the plurality of thermoresponsive alkylations comprise hydroxybutyl groups.

[0743] Example 16: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-15, wherein the plurality of zwitterionic functionalizations are derived from a zwitterionic agent comprising sulfobetaines (quaternary ammonium paired with sulfonate), carboxybetaines (quaternary ammonium paired with carboxylate), phosphobetaines / phosphorylcholine-like groups (quaternary ammonium or phosphonium paired with phosphate, phosphonate, or related oxyanions), or a combination thereof.

[0744] Example 17: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-16, wherein the plurality of zwitterionic functionalizations are derived from a zwitterionic agent comprising (3-((3-chloropropyl)dimethylammonio)propane-l-sulfonate).

[0745] Example 18: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-17, wherein the molecularly functionalized biomass-derived hydrogel further comprises a salt.

[0746] Example 19: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly example 18, wherein the salt comprises a hydroscopic salt.

[0747] Example 20: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly example 18 or example 19, wherein the salt comprises a lithium salt, a calcium salt, a magnesium salt, a zinc salt, an aluminum salt, an iron salt, a copper salt, a sodium salt, a potassium salt, an ammonium salt, or a combination thereof.

[0748] Example 21: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 18-20, wherein the salt comprises a chloride salt, a bromide salt, an iodide salt, a hydroxide salt, a carbonate salt, an acetate salt, a perchlorate salt, a sulfate salt, a nitrate salt, or a combination thereof.

[0749] Example 22: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 18-21, wherein the salt comprises Lithium chloride (LiCl), lithium bromide (LiBr), lithium iodide (Lil), calcium chloride (CaCl₂), calcium bromide (CaBr₂), magnesium chloride (MgCl₂), magnesium bromide (MgBr₂), zinc chloride (ZnCl₂), aluminum chloride (AlCl₃, typically as hydrates / complexes), ferric chloride (FeCl₃), copper(II) chloride (CuCl₂), sodium hydroxide (NaOH), potassium hydroxide (KOH), potassium carbonate (K₂CO₃), sodium carbonate (Na₂CO₃), potassium acetate (KOAc), sodium acetate (NaOAc), magnesium perchlorate (Mg(ClO₄)₂), calcium perchlorate (Ca(ClO₄)₂), sodium perchlorate (NaClO₄), potassium perchlorate (KClO₄), sodium sulfate (Na₂SO₄, notably as hydrates), magnesium10046-676W01; 8637 YU sulfate (MgSO₄, notably as hydrates), calcium nitrate (Ca(NO₃)₂), magnesium nitrate (Mg(NO₃)₂), zinc nitrate (Zn(NO₃)₂), ammonium nitrate (NH₄NO₃), ammonium chloride (NH₄Cl), and ammonium sulfate ((NH₄)₂SO₄).

[0750] Example 23: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 18-22, wherein the salt comprises a lithium salt, a calcium salt, or a combination thereof.

[0751] Example 24: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 18-23, wherein the salt comprises LiCl, CaCl₂, or a combination thereof.

[0752] Example 25: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-24, wherein the molecularly functionalized biomass-derived hydrogel is crosslinked.

[0753] Example 26: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-25, wherein the molecularly functionalized biomass-derived hydrogel is further derived from one or more crosslinking monomers.

[0754] Example 27: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-26, wherein the molecularly functionalized biomass-derived hydrogel has a lower critical solution temperature of from 10 to 80°C, such as from 30 to 60°C.

[0755] Example 28: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-27, wherein the molecularly functionalized biomass-derived hydrogel exhibits enhanced water uptake under a range of relative humidity (RH) conditions (e.g., 5%-100%, such as from 15-60%), stabilizes hygroscopic salts, enables energy-efficient water release at moderate temperatures (~50-60°C), or a combination thereof.

[0756] Example 29: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-28, wherein the molecularly functionalized biomass-derived hydrogel demonstrates high sorption-desorption cycling stability.

[0757] Example 30: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-29, wherein the molecularly functionalized biomass-derived hydrogel shows a water uptake of from 0.1 to 10 grams of water per gram of hydrogel, such as from 0.86-1.32 g g”!, at 15—30% relative humidity (RH).

[0758] Example 31: The molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-30, wherein the molecularly functionalized biomass-derived hydrogel has a water collection rate of from 1 to 50 kg kg-1day-1in outdoor conditions, such as 14 kg kg-1day-1or more.10046-676W01; 8637 YU Example 32: An interpenetrating network derived from the molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-31.

[0759] Example 33: A method of making the molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-31.

[0760] Example 34: A method of molecularly functionalizing a biomass-derived hydrogel, the method comprising: performing alkylation of a polysaccharide derived from a biomass to thereby functionalize the polysaccharide with a plurality of thermoresponsive alkylations; and integrating zwitterionic groups into the polysaccharide to thereby functionalize the polysaccharide with a plurality of zwitterionic functionalizations.

[0761] Example 35: The method of any example herein, particularly example 34, wherein the zwitterionic functionalization is performed after the alkylation.

[0762] Example 36: The method of any example herein, particularly example 34 or example 35, wherein the zwitterionic functionalization comprises a plurality of zwitterionic functionalization steps.

[0763] Example 37: The method of any example herein, particularly examples 34-36, wherein the alkylation is via an epoxide ring-opening reaction.

[0764] Example 38: The method of any example herein, particularly examples 34-37, wherein the zwitterionization is via Williamson etherification.

[0765] Example 39: The method of any example herein, particularly examples 34-38, wherein the method further comprises extracting the polysaccharide from the biomass.

[0766] Example 40: The method of any example herein, particularly examples 34-39, wherein the molecularly functionalized biomass-derived hydrogel made by the method comprises the molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-31.

[0767] Example 41: The method of any example herein, particularly examples 33-40, wherein the method is a cost-effective large-scale synthesis, for example via supercritical CO₂ processing and / or continuous flow chemistry.

[0768] Example 42: A method of use of the molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-31 and / or the interpenetrating network of any example herein, particularly example 32.

[0769] Example 43: The method of any example herein, particularly example 42, wherein the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network for atmospheric water harvesting.

[0770] Example 44: The method of any example herein, particularly example 43, wherein the10046-676W01; 8637 YU method comprises passive or solar-assisted water recovery.

[0771] Example 45: The method of any example herein, particularly examples 42-44, wherein the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network for humidity control in an enclosed space.

[0772] Example 46: The method of any example herein, particularly examples 42-45, wherein the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network in a thermal management or passive cooling application.

[0773] Example 47: The method of any example herein, particularly examples 42-46, wherein the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network in pharmaceutical and / or food packaging.

[0774] Example 48: The method of any example herein, particularly examples 42-47, wherein the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network in water collection, water purification, water management, or a combination thereof.

[0775] Example 49: The method of any example herein, particularly examples 42-48, wherein the method comprises using the molecularly functionalized biomass-derived hydrogel and / or the interpenetrating network in water capture, water logistics, process water, humidity control, humidity preservation, humidity packaging, building materials, HVAC integration, thermal management, cooling, gas drying, industrial separations, corrosion control, materials protection, or a combination thereof.

[0776] Example 50: An article of manufacture comprising the molecularly functionalized biomass-derived hydrogel of any example herein, particularly examples 1-31 and / or the interpenetrating network of any example herein, particularly example 32.

[0777] Example 51: The article of any example herein, particularly example 50, wherein the article comprises an atmospheric water harvesting device, e.g., an indoor and / or outdoor atmospheric water harvesting device.

[0778] Example 52: The article of any example herein, particularly example 50 or example 51, wherein the article comprises a portable water harvester, a self-sustaining irrigation system, an emergency drinking water device, or a combination thereof.

[0779] Other advantages which are obvious and which are inherent to the invention will be evident to one skilled in the art. It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments10046-676W01; 8637 YU may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

[0780] The compositions, systems, and methods of the appended claims are not limited in scope by the specific compositions, system, and methods described herein, which are intended as illustrations of a few aspects of the claims and any methods that are functionally equivalent are intended to fall within the scope of the claims. Various modifications of the compositions, systems, and methods in addition to those shown and described herein are intended to fall within the scope of the appended claims. Further, while only certain representative composition elements, system elements, and method steps disclosed herein are specifically described, other combinations of the composition elements, system elements, and method steps also are intended to fall within the scope of the appended claims, even if not specifically recited. Thus, a combination of steps, elements, components, or constituents may be explicitly mentioned herein or less, however, other combinations of steps, elements, components, and constituents are included, even though not explicitly stated.

Claims

10046-676W01; 8637 YU CLAIMSWhat is claimed:

1. A molecularly functionalized biomass-derived hydrogel, comprising a polysaccharide derived from a biomass functionalized with a plurality of thermoresponsi ve alkylations and a plurality of zwitterionic functionalizations.

2. The molecularly functionalized biomass-derived hydrogel of claim 1, wherein the polysaccharide is derived from a sustainable biomass feedstock.

3. The molecularly functionalized biomass-derived hydrogel of claim 1 or claim 2, wherein the polysaccharide comprises a carbohydrate.

4. The molecularly functionalized biomass-derived hydrogel of any one of claims 1-3, wherein the polysaccharide comprises cellulose, starch, chitosan, or a combination thereof.

5. The molecularly functionalized biomass-derived hydrogel of any one of claims 1-4, wherein the plurality of thermoresponsive alkylations disrupt the hydrogen bond network of the polysaccharide to facilitate further modifications, and balance hydrophobic and hydrophilic elements to confer thermoresponsiveness, enabling the hydrophobic interaction at elevated temperatures to ease the release of water molecules.

6. The molecularly functionalized biomass-derived hydrogel of any one of claims 1-5, wherein the plurality of thermoresponsive alkylations comprise hydroxypropyl groups, hydroxybutyl groups, or a combination thereof.

7. The molecularly functionalized biomass-derived hydrogel of any one of claims 1-6, wherein the plurality of zwitterionic functionalizations are derived from a zwitterionic agent comprising (3-((3-chloropropyl)dimethylammonio)propane-l -sulfonate).

8. The molecularly functionalized biomass-derived hydrogel of any one of claims 1-7, wherein the molecularly functionalized biomass-derived hydrogel further comprises a salt.

9. The molecularly functionalized biomass-derived hydrogel of claim 8, wherein the salt comprises a hydroscopic salt.

10. The molecularly functionalized biomass-derived hydrogel of any one of claims 1-9, wherein the molecularly functionalized biomass-derived hydrogel has a lower critical solution temperature of from 10 to 80°C, such as from 30 to 60°C.

11. The molecularly functionalized biomass-derived hydrogel of any one of claims 1-10, wherein the molecularly functionalized biomass-derived hydrogel exhibits enhanced water10046-676W01; 8637 YU uptake under a range of relative humidity (RH) conditions (e.g., 5%-100%, such as from 15-60%), stabilizes hygroscopic salts, enables energy-efficient water release at moderate temperatures (~50-60°C), or a combination thereof.

12. The molecularly functionalized biomass-derived hydrogel of any one of claims 1-11, wherein the molecularly functionalized biomass-derived hydrogel demonstrates high sorption¬ desorption cycling stability.

13. The molecularly functionalized biomass-derived hydrogel of any one of claims 1-12, wherein the molecularly functionalized biomass-derived hydrogel shows a water uptake of from 0.1 to 10 grams of water per gram of hydrogel, such as from 0.86-1.32 g g-1, at 15-30% relative humidity (RH).

14. The molecularly functionalized biomass-derived hydrogel of any one of claims 1-13, wherein the molecularly functionalized biomass-derived hydrogel has a water collection rate of from 1 to 50 kg kg1day4in outdoor conditions, such as 14 kg kg4day4or more.

15. An interpenetrating network derived from the molecularly functionalized biomass-derived hydrogel of any one of claims 1-14.

16. A method of making the molecularly functionalized biomass-derived hydrogel of any one of claims 1-14.

17. A method of molecularly functionalizing a biomass-derived hydrogel, the method comprising:performing alkylation of a polysaccharide derived from a biomass to thereby functionalize the polysaccharide with a plurality of thermoresponsive alkylations; and integrating zwitterionic groups into the polysaccharide to thereby functionalize the polysaccharide with a plurality of zwitterionic functionalizations.

18. The method of claim 17, wherein the zwitterionic functionalization is performed after the alkylation.

19. The method of claim 17 or claim 18, wherein the zwitterionic functionalization comprises a plurality of zwitterionic functionalization steps.

20. A method of use of the molecularly functionalized biomass-derived hydrogel of any one of claims 1-14 and / or the interpenetrating network of claim 15.

21. An article of manufacture comprising the molecularly functionalized biomass-derived hydrogel of any one of claims 1-14 and / or the interpenetrating network of claim 15.

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