A method and application of bamboo deconstruction and gel construction based on a catalytic ternary eutectic solvent system

Abstract

This invention provides an integrated method and application for the deconstruction and gel construction of moso bamboo based on a catalytic ternary eutectic solvent system. The method includes the following steps: mixing moso bamboo powder with a catalytic ternary eutectic solvent, pretreating, and separating the solid and liquid components to obtain a pretreated liquid and a solid residue; washing and drying the solid residue, followed by semi-simultaneous saccharification and fermentation to obtain bioethanol; mixing the pretreated liquid, acrylic acid, ethylene glycol, zinc chloride, a crosslinking agent, and a photoinitiator, prepolymerizing, and curing under ultraviolet light to obtain a eutectic gel. This invention utilizes a catalytic ternary eutectic solvent system to achieve integrated deconstruction of moso bamboo, saccharification and fermentation of cellulose residue to produce ethanol, and gel construction with the pretreated liquid. The resulting gel exhibits excellent mechanical properties, self-healing properties, bioadhesion, environmental stability, ultraviolet shielding properties, excellent strain sensing characteristics, and long-term cycling stability, showing broad application prospects in cutting-edge fields such as flexible electronics, biomedicine, and intelligent sensors.

Description

Technical Field

[0001] This invention belongs to the field of biomass refining, specifically relating to an integrated method and application of bamboo deconstruction and gel construction based on a catalytic ternary eutectic solvent system. Background Technology

[0002] Currently, global energy demand is projected to grow by over 28% by 2040, and the problems of fossil fuel depletion and carbon emissions urgently need to be addressed. Therefore, using renewable biomass to replace fossil fuels, fuels, and energy sources to solve current environmental problems is a hot research topic. Moso bamboo, as a rapidly growing and abundant natural lignocellulose raw material, has three main components (cellulose, hemicellulose, and lignin) all with significant utilization value. However, the dense cell wall structure and complex lignin-carbohydrate complex of moso bamboo constitute a strong natural anti-destruction barrier, making it difficult to achieve its gentle and efficient value conversion using conventional solvents and chemical methods.

[0003] To overcome this bottleneck, eutectic solvents (DES), as a green and designable solvent system, can remove most of the lignin and hemicellulose during pretreatment, while retaining cellulose. Although DES shows great promise in biomass pretreatment, its biocatalytic compatibility and efficiency in the decomposition of lignocellulose still need improvement. For example, in the traditional single-method DES treatment of bamboo, the limited catalytic capacity, insufficient permeability, and insufficient reaction selectivity of the solvent itself often necessitate harsh conditions such as high temperature and long processing times. To further enhance decomposition, researchers have also attempted to introduce external catalysts (inorganic acids). However, such methods typically face problems such as difficult catalyst recovery, strong corrosiveness to equipment, and poor compatibility with the DES system, and may even introduce impurities, affecting the purity and performance of the final gel product.

[0004] In summary, the fundamental flaw in both single DES and simple catalyst composites lies in the failure of existing technologies to successfully construct a novel DES system that integrates efficient dissolution and precise catalysis. However, current research largely focuses on solid cellulose obtained from biomass treatment with DES, while the DES pretreatment liquid, rich in lignin and other active components, is often discarded as a byproduct. This not only wastes resources but also increases the burden on subsequent wastewater treatment. In fact, this pretreatment liquid itself possesses the potential to directly construct functional materials. Bio-based gels, as bio-based functional materials with a three-dimensional network structure, show broad application prospects in biomedicine, flexible electronics, synthetic chemistry, and environmental fields. Currently, commercial gel production often involves harsh conditions such as high temperatures and strong acids / bases, leading to high energy consumption, environmental pollution, and poor product biocompatibility.

[0005] Therefore, there is an urgent need in this field for an innovative solvent system and resource utilization strategy, and a new biomass refining technology that can not only efficiently and selectively decompose bamboo, but also directly utilize the active components after decomposition at high value. Summary of the Invention

[0006] This invention aims to overcome the core limitations of existing technologies, such as the low efficiency of single DES and the poor compatibility and complex processes of introducing external catalysts. It creatively proposes an integrated method and application for the deconstruction and gelation of moso bamboo based on a catalytic ternary eutectic solvent system. This invention utilizes a catalytic ternary eutectic solvent system to achieve the integrated deconstruction of moso bamboo, saccharification and fermentation of cellulose residue to produce ethanol, and gelation of the pretreatment solution.

[0007] The core idea of ​​this invention lies in constructing a ternary eutectic solvent (DES) system with tetrabutylammonium chloride (TBAC) as the hydrogen bond acceptor, lactic acid (LA) as the hydrogen bond donor, and p-toluenesulfonic acid (PTSA), which has both hydrogen bond donor and catalytic functions, as key components. In this system, PTSA, as a strong acidic organic catalyst, can catalyze the in-situ and highly efficient cleavage of lignin-carbohydrate complexes (LCC bonds) in the cell walls of moso bamboo, significantly weakening its dense structure, thereby achieving efficient deconstruction of moso bamboo under mild conditions. The pretreated solution obtained after deconstruction is itself rich in active components derived from moso bamboo and can be directly used as the core raw material for preparing bio-based gels without any separation or purification steps. Ultimately, this invention achieves a short-process, high-efficiency conversion from moso bamboo raw materials to eutectic gel products through a catalytic solvent system and a single core reaction step, truly realizing the efficient deconstruction and high-value utilization of biomass, and fully embodying the concepts of green chemistry and atom economy.

[0008] The technical solution of the present invention is as follows:

[0009] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system includes the following steps:

[0010] (1) Mix bamboo powder with a catalytic ternary eutectic solvent, pretreat, and separate solid and liquid to obtain pretreated liquid and solid residue;

[0011] (2) After washing and drying, the solid residue is fermented by semi-synchronous saccharification to obtain bioethanol;

[0012] (3) Mix the pretreatment liquid, acrylic acid, ethylene glycol, zinc chloride, crosslinking agent and photoinitiator, prepolymerize and cure with ultraviolet light to obtain eutectic gel.

[0013] According to a preferred embodiment of the present invention, in step (1), the method for preparing the bamboo powder includes the following steps: washing, drying, slicing, crushing, screening, and drying bamboo to obtain bamboo powder with a particle size of 40-60 mesh.

[0014] According to a preferred embodiment of the present invention, in step (1), the preparation method of the catalytic ternary eutectic solvent includes the following steps: mixing tetrabutylammonium chloride (TBAC), lactic acid (LA) and p-toluenesulfonic acid (PTSA), and reacting them to obtain the catalytic ternary eutectic solvent.

[0015] Preferably, the molar ratio of tetrabutylammonium chloride (TBAC), lactic acid (LA), and p-toluenesulfonic acid (PTSA) is 1:2:0.06-0.1.

[0016] Preferably, the reaction temperature is 50-80℃, the reaction time is 30-60 min, and the reaction is carried out under stirring conditions.

[0017] According to a preferred embodiment of the present invention, in step (1), the mass ratio of bamboo powder to catalytic ternary eutectic solvent is 1:10-20.

[0018] According to a preferred embodiment of the present invention, in step (1), the pretreatment temperature is 60-100 °C, the pretreatment time is 10-30 minutes, and the pretreatment is carried out under stirring conditions.

[0019] According to the present invention, in step (2), the semi-synchronous saccharification and fermentation can be carried out using existing methods.

[0020] According to a preferred embodiment of the present invention, in step (3), the mass ratio of pretreatment liquid to acrylic acid is 0.3-1:1-4; the mass ratio of acrylic acid, ethylene glycol, and zinc chloride is 1-4:0.3-1:0.4-0.6; and the mass ratio of acrylic acid, crosslinking agent, and photoinitiator is 1-4:0.4-0.8:0.01-0.05.

[0021] According to a preferred embodiment of the present invention, in step (3), the crosslinking agent is polyethylene glycol diacrylate (PEGDA).

[0022] According to a preferred embodiment of the present invention, in step (3), the photoinitiator is 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone.

[0023] According to a preferred embodiment of the present invention, in step (3), the prepolymer reaction conditions are as follows: stirring at 70-80°C for 2-4 hours until a homogeneous prepolymer solution is formed.

[0024] According to a preferred embodiment of the present invention, in step (3), the ultraviolet curing time is 5-20 minutes.

[0025] A eutectic gel was prepared by the method described above.

[0026] Applications of the aforementioned eutectic gels in flexible electronics, biomedicine, or smart sensor devices.

[0027] Technical features and beneficial effects of the present invention:

[0028] Compared with existing technologies, this invention achieves the co-production of ethanol and eutectic gel by synthesizing a DES system that integrates solvent and catalyst, resulting in the following breakthrough and beneficial effects:

[0029] (1) DES system integrating solvent and catalyst: This invention uses PTSA with catalytic function to synthesize DES, creating a catalytic eutectic solvent system. This homogeneous catalytic system at the microscopic level makes the reaction more thorough and uniform, greatly improving the accessibility and conversion efficiency of bamboo components.

[0030] (2) Efficient deconstruction under mild conditions: The ternary DES can efficiently and selectively break the lignin-carbohydrate complex bond in moso bamboo under mild conditions, thereby selectively and efficiently deconstructing moso bamboo, achieving efficient removal of lignin and hemicellulose, maximizing the preservation of the natural degree of polymerization and integrity of cellulose, and significantly reducing the pretreatment reaction temperature and time.

[0031] (3) Improved process economy and atom economy: In-situ preparation of gel from pretreatment liquid significantly shortens the process and reduces equipment investment and energy consumption. The entire process does not generate chlorine-containing or toxic waste, significantly reducing emissions of waste gas, wastewater, and solid waste, lowering environmental treatment costs, and embodying the core concept of green chemistry. At the same time, the cellulose component separated in the process can be semi-simultaneously saccharified and fermented to produce ethanol, greatly improving the atom economy of the entire biomass refining process and bringing significant economic and environmental benefits to the enterprise.

[0032] (4) Excellent comprehensive performance: The tensile strain reaches 747%, the compressive strength reaches 954 kPa, and the toughness reaches 2123 kJ / m³. This is mainly attributed to the lignin nanoparticles in the pretreatment solution acting as physical cross-linking points in the gel network, effectively hindering the slippage of polymer chains. This gel not only has excellent self-healing ability (healing efficiency of 86% after 72 hours) and significant bioadhesion (adhesion strength to pigskin reaches 20.81 kPa), but also exhibits extremely strong environmental stability, maintaining flexibility even at extremely low temperatures of -70℃, and possessing complete ultraviolet shielding performance (transmittance in the 200-360 nm band is close to 0). With its excellent strain sensing characteristics (sensitivity factor 1.31, response time 1.16 s) and long-term cycling stability, this material has broad application prospects in cutting-edge fields such as flexible electronics, biomedicine, and smart sensor devices.

[0033] (5) The preparation method of this invention, as a whole, achieves its excellent effect through the combined action of various conditions. PTSA, as a component of DES, not only participates in the construction of the gel network mechanism, but also achieves precise targeted breaking of the LCC bond of moso bamboo due to its strong protic acid properties, realizing efficient deconstruction of moso bamboo in a shorter time (10-30 min). Without PTSA, the removal rate of lignin and hemicellulose is not high, resulting in a serious lack of deconstruction efficiency, which leads to low lignin and hemicellulose content in the pretreatment solution, affecting the performance of the eutectic gel. Changing the molar ratio of TBAC, LA and PTSA can adjust the catalytic intensity, affect the deconstruction of moso bamboo, and directly affect the subsequent ethanol conversion rate. If choline chloride is used to replace TBAC, the deconstruction ability will decrease significantly, the removal rate of hemicellulose and lignin will decrease, and the tensile strain of the resulting gel will drop sharply from 747% to 142%, proving the irreplaceable role of TBAC in constructing an efficient deconstruction system. The mass ratio of moso bamboo powder to DES is controlled between 1:10-20 to ensure that the material is fully wetted and maintains efficient reaction. DES not only acts as a solvent but also participates in gel formation, imparting antifreeze properties and inhibiting ice crystal growth. Zinc chloride, as a conductive salt, provides ion transport channels, enhancing the ionic conductivity of the gel, and simultaneously forms coordination interactions with polymer chains, contributing to improved network density and mechanical stability. With increasing pretreatment solution dosage, the mechanical strength of the gel initially increases and then decreases. A suitable amount of lignin acts as a rigid reinforcing phase, but excessive amounts can lead to gel embrittlement and brittle fracture. Omitting acrylic acid or PEGDA will prevent the formation of a stable three-dimensional network, resulting in a fluid-like product or one with extremely low strength, making it unsuitable for molding. Ethylene glycol, along with the DES component in the pretreatment solution, plays a plasticizing role; its omission will cause the gel to lose flexibility at low temperatures. Attached Figure Description

[0034] Figure 1 These are mechanical property diagrams of the eutectic gel prepared in the examples; where (a)-(b) are tensile strain diagrams, (c)-(d) are Young's modulus and toughness diagrams, and (e)-(f) are compressive strain diagrams; (a), (c), and (e) show the relationship between the mechanical properties of the eutectic gel and the mass of the pretreatment solution, and (b), (d), and (f) show the relationship between the mechanical properties of the eutectic gel and the mass of ethylene glycol.

[0035] Figure 2 The graph shows the sensing performance of the eutectic gel prepared in Example 1; where (a) is the resistance change at different strains (25~100%), (b) is the resistance change at different stretching rates (100~400 mm / min), (c)-(e) is the resistance change after 400 stretches at 100% strain, and (f) is the response time test graph.

[0036] Figure 3These are the sensing performance diagrams of the eutectic gel prepared in Example 1; wherein, (a)-(c) are resistance change diagrams of wrist, elbow and finger movements detected by the eutectic gel strain sensor, (d) is the GF diagram of the eutectic gel strain sensor, and (e)~(f) are resistance change diagrams of running and walking monitored by the eutectic gel strain sensor.

[0037] Figure 4 These are bioelectrode images of the eutectic gel prepared in Example 1; where (a)-(b) are electromyography signal images, (c)-(e) are electrocardiogram signal images, and (f)-(g) are carotid artery signal images. Detailed Implementation

[0038] The present invention will now be described in detail. Before proceeding with the description, it should be understood that the terminology used in this specification and the appended claims should not be construed as limited to its general or dictionary meaning, but rather should be interpreted according to the meaning and concept corresponding to the technical aspects of the invention, based on the principle that the inventors are allowed to appropriately define the terms for the best interpretation. Therefore, the description presented herein is merely an illustrative example of preferred embodiments and is not intended to limit the scope of the invention. It should be understood that other equivalents or modifications can be obtained from it without departing from the spirit and scope of the invention.

[0039] The following embodiments are merely examples of implementation schemes of the present invention and do not constitute any limitation on the present invention. Those skilled in the art will understand that any modifications that do not depart from the spirit and concept of the present invention fall within the protection scope of the present invention.

[0040] Example 1

[0041] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system includes the following steps:

[0042] (1) Raw material preparation: Take fresh bamboo with a growth cycle of 3 years, wash it repeatedly with deionized water to remove impurities such as mud and sand attached to the surface, dry it, slice it and crush it with a pulverizer, screen and collect bamboo powder with a particle size of 40-60 mesh, dry it in an oven at 60℃ to constant weight to obtain bamboo powder with a particle size of 40-60 mesh.

[0043] (2) Preparation of eutectic solvent (DES): Weigh tetrabutylammonium chloride (TBAC), lactic acid (LA) and p-toluenesulfonic acid (PTSA) to a molar ratio of 1:2:0.06 and mix them. Place the mixture in a constant temperature magnetic stirring water bath at 80℃ and stir continuously for 30 min until a homogeneous, clear, and transparent liquid is formed to obtain a catalytic ternary eutectic solvent, which is then sealed and stored for later use.

[0044] (3) DES treatment: The bamboo powder obtained above is mixed with the DES solvent prepared in step (2) at a solid-liquid mass ratio of 1:20. The mixture is placed in a constant temperature oil bath at 80°C and mechanically stirred for 30 minutes.

[0045] (4) Post-treatment: After the reaction, the mixture was cooled to room temperature and centrifuged. The resulting solid slurry and DES filtrate containing lignin, sugars, and other dissolved substances were separated, which was the pretreatment solution (labeled PL4). The solid phase was repeatedly washed with a mixed solution of ethanol and water (volume ratio 1:9) until the pH of the washing water was neutral. The washed solid was dried in an oven at 60 °C to constant weight to obtain a cellulose-rich solid residue, which was labeled C. 80-30-0.06 .

[0046] For solid residue C 80-30-0.06 The components were analyzed, and the solid residue rate was 42.95%, the lignin removal rate was 84.10%, and the hemicellulose removal rate was 87.29%.

[0047] For solid residue C 80-30-0.06 X-ray diffraction analysis revealed that its crystallinity was 57.75%, which was significantly higher than that of untreated bamboo raw material (44.70%).

[0048] For solid residue C 80-30-0.06 Semi-simultaneous saccharification and fermentation experiments were conducted. Solid residue, cellulase, and water were mixed thoroughly (mass ratio of solid residue, cellulase, and water: 1:0.02:10), and the temperature was set at 50 °C for 24 h of enzymatic hydrolysis. The temperature was then lowered to 40 °C, and brewer's yeast (mass ratio of brewer's yeast to solid residue: 0.1:100) was added, followed by fermentation for 72 hours. Solid impurities in the fermentation broth were removed by centrifugation, and the ethanol concentration was determined by high-performance liquid chromatography (HPLC). The ethanol yield was calculated as: Ethanol yield (%) = (Actual ethanol yield / Theoretical ethanol yield) × 100%. The ethanol yield reached 95.04%.

[0049] (5) Preparation of eutectic gel: Take 0.5 g of pretreatment solution PL4 obtained in step (4), 4 g of acrylic acid, 5.5 g of catalytic ternary eutectic solvent prepared by method in step (2), 0.5 g of ethylene glycol, 0.5 g of zinc chloride, 0.6 g of crosslinking agent polyethylene glycol diacrylate (PEGDA) (number average molecular weight Mn≈700) and 25 mg of photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (Irgacure 2959) into a reagent bottle. Place the mixture on a constant temperature magnetic stirrer at 75 ℃ and stir at 500 rpm for 2 h until a homogeneous prepolymer solution is formed. Then, pour the prepolymer solution into a mold and irradiate it under ultraviolet light for 10 minutes to obtain a transparent bio-based gel (PL4). 4-0.5 EG 0.5 ).

[0050] The PL obtained in this embodiment 4-0.5 EG 0.5 The eutectic gel underwent systematic testing and demonstrated excellent overall performance.

[0051] In terms of mechanical properties: such as Figure 1 As shown, the tensile strain reaches 747%, the tensile stress is 574 kPa, the compressive strength is 954 kPa, the Young's modulus is 57 kPa, and the toughness is as high as 2123 kJ / m³.

[0052] In terms of functional features:

[0053] Self-healing: The prepared gel strip was cut in half, dividing it into two completely independent parts. The cut surfaces were then brought back into contact and placed in a constant temperature and humidity chamber (25°C, 50% relative humidity). After 72 hours, the strip was removed and subjected to a tensile test. Healing efficiency = (fracture energy of the healed strip / fracture energy of the original strip) × 100%. The healing efficiency after 72 hours was 86%, demonstrating excellent self-healing ability.

[0054] Wide temperature range adaptability: The specimen was placed in a programmed cooling chamber and cooled to -70°C at a certain rate (5°C / min) and held at that temperature. Bending, torsion, or knotting tests were then performed directly at -70°C to observe whether the specimen became brittle. It maintained its flexibility at -70°C, demonstrating wide temperature range adaptability.

[0055] UV shielding performance: A thin film of gel with a thickness of approximately 1-2 mm was attached to a cuvette holder. Light transmittance curves were measured in the 200-800 nm wavelength range. The transmittance in the 200-360 nm band approached zero, indicating complete UV shielding performance.

[0056] Adhesion performance: The gel was applied to the surface of pigskin, a certain load (1 kg weight) was applied, and the mixture was left to stand for a certain time (10 min) to ensure close contact. The adhesion force was measured at a speed of 60 mm / min. Adhesion strength = maximum shear force / contact area. The adhesion strength of the pigskin was 20.81 kPa, demonstrating significant adhesion performance.

[0057] These properties indicate that this gel material has significant application potential in cutting-edge fields such as flexible electronics, biomedicine, and intelligent sensing.

[0058] Example 2

[0059] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that: in step (3) DES treatment, the reaction temperature is increased from 80 ℃ to 100 ℃; other steps and conditions are the same as in Example 1.

[0060] The solid residue C obtained in step (4) 100-30-0.06 The components were analyzed, and the solid residue rate was 40.29%, the lignin removal rate was 86.28%, and the hemicellulose removal rate was 95.23%.

[0061] The solid residue C obtained in step (4) 100-30-0.06 X-ray diffraction analysis showed that its crystallinity was 58.71%, which was significantly higher than that of untreated bamboo raw material (44.70%).

[0062] The solid residue C obtained in step (4) 100-30-0.06 A semi-synchronous saccharification and fermentation experiment was conducted according to the method in Example 1, and the ethanol yield reached 98.28% after 72 hours.

[0063] Conclusion: Increasing the DES treatment temperature helps to enhance its catalytic decomposition efficiency, thereby simultaneously increasing the yield of cellulosic ethanol.

[0064] Example 3

[0065] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system, as described in Example 1, except that: in step (3) DES treatment, the reaction time is reduced from 30 min to 20 min; other steps and conditions are the same as in Example 1.

[0066] The solid residue C obtained in step (4) 80-20-0.06 The components were analyzed, and the solid residue rate was 43.34%, the lignin removal rate was 80.49%, and the hemicellulose removal rate was 85.53%.

[0067] The solid residue C obtained in step (4) 80-20-0.06X-ray diffraction analysis revealed that its crystallinity was 56.34%, which was significantly higher than that of untreated bamboo raw material (44.70%).

[0068] The solid residue C obtained in step (4) 80-20-0.06 A semi-synchronous saccharification and fermentation experiment was conducted according to the method in Example 1, and the ethanol yield reached 92.62% after 72 hours.

[0069] Conclusion: Shortening the reaction time of DES treatment will reduce catalytic deconstruction efficiency and ethanol yield.

[0070] Example 4

[0071] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that the molar ratio of TBAC, LA and PTSA in step (2) is adjusted from 1:2:0.06 to 1:2:0.1; other steps and conditions are the same as in Example 1.

[0072] The solid residue C obtained in step (4) 80-30-0.1 Analysis showed that the solid residue rate was 40.96%, the lignin removal rate was 78.37%, and the hemicellulose removal rate was 92.17%.

[0073] The solid residue C obtained in step (4) 80-30-0.1 X-ray diffraction analysis revealed that its crystallinity was 62.14%, which was significantly higher than that of untreated bamboo raw material (44.70%).

[0074] The solid residue C obtained in step (4) 80-30-0.1 A semi-synchronous saccharification and fermentation experiment was conducted according to the method in Example 1, and the ethanol yield reached 97.53% after 72 hours.

[0075] Conclusion: Adjusting the molar ratio of DES feedstock can effectively change its catalytic decomposition ability, thereby achieving characteristic regulation of the degree of decomposition of bamboo tissue and the yield of cellulose ethanol.

[0076] Example 5

[0077] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that the amount of pretreatment solution PL4 in step (5) is adjusted from 0.5g to 0.8g, while the amount of ethylene glycol remains at 0.5g; other steps and conditions are the same as in Example 1. A transparent bio-based gel (PL4) is obtained. 4-0.8 EG 0.5 ).

[0078] The PL obtained in this embodiment 4-0.8 EG 0.5 The eutectic gel underwent systematic testing and demonstrated excellent overall performance.

[0079] In terms of mechanical properties: such as Figure 1 As shown, the tensile strain reaches 581%, the tensile stress is 330 kPa, the compressive strength reaches 573 kPa, and the toughness is as high as 883 kJ / m. 3 Young's modulus is 46 kPa.

[0080] In terms of functional features:

[0081] Adhesion performance was tested according to the method in Example 1, and the adhesion strength of the pigskin was 15.4 kPa.

[0082] Conclusion: The quality of the pretreatment solution affects the mechanical and adhesive properties of the gel. The stress and compressive strength of the gel initially increase and then decrease with increasing pretreatment solution quality (0.5g pretreatment solution is the optimal condition). This is because lignin in the pretreatment solution, as rigid nanoparticles dispersed in the gel network, acts as physical cross-linking points, hindering polymer chain slippage and thus improving mechanical strength. However, excessive lignin may lead to gel embrittlement, resulting in decreased mechanical strength. Furthermore, the adhesive strength of the gel also initially increases and then decreases with increasing pretreatment solution quality. This is because lignin, as a rigid component in the pretreatment solution, increases cross-linking density and improves the modulus of the eutectic gel; however, excessive lignin may induce brittle fracture and reduce dynamic adhesive stability. Therefore, a suitable pretreatment solution quality improves the mechanical strength and adhesive properties of the eutectic gel.

[0083] Example 6

[0084] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that the amount of pretreatment solution PL4 in step (5) is adjusted from 0.5g to 1g, while the amount of ethylene glycol remains at 0.5g; other steps and conditions are the same as in Example 1. A transparent bio-based gel (PL4) is obtained. 4-1 EG 0.5 ).

[0085] The PL obtained in this embodiment 4-1 EG 0.5 The eutectic gel underwent systematic testing and demonstrated excellent overall performance.

[0086] In terms of mechanical properties: such as Figure 1 As shown, the tensile strain reaches 696%, the tensile stress is 280 kPa, the compressive strength reaches 295 kPa, and the toughness reaches 792 kJ / m. 3 Young's modulus is 28 kPa.

[0087] In terms of functional features:

[0088] Adhesion performance was tested according to the method in Example 1. The adhesion strength of the pigskin was 11 kPa, which shows significant adhesion performance.

[0089] Conclusion: The quality of the pretreatment solution affects the mechanical and adhesive properties of the gel. The stress and compressive strength of the gel initially increase and then decrease with increasing pretreatment solution quality. This is because lignin in the pretreatment solution, acting as rigid nanoparticles dispersed in the gel network, serves as physical cross-linking points, hindering polymer chain slippage and thus improving mechanical strength. However, excessive lignin may lead to gel embrittlement, resulting in decreased mechanical strength. Furthermore, the adhesive strength of the gel also initially increases and then decreases with increasing pretreatment solution quality. This is because lignin, as a rigid component, increases cross-linking density and enhances the modulus of the eutectic gel; however, excessive lignin may induce brittle fracture and reduce dynamic adhesive stability. Therefore, a suitable pretreatment solution quality improves the mechanical strength and adhesive properties of the eutectic gel.

[0090] Example 7

[0091] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that the amount of ethylene glycol in step (5) is adjusted from 0.5g to 0.8g, and the amount of pretreatment solution PL4 is kept at 0.5g; other steps and conditions are the same as in Example 1. A transparent bio-based gel (PL4) is obtained. 4-0.5 EG 0.8 ).

[0092] The PL obtained in this embodiment 4-0.5 EG 0.8 The eutectic gel underwent systematic testing and demonstrated excellent overall performance.

[0093] In terms of mechanical properties: such as Figure 1 As shown, the tensile strain reaches 585%, the tensile stress is 399 kPa, the compressive strength reaches 574 kPa, and the toughness is as high as 974 kJ / m. 3 Young's modulus is 57 kPa.

[0094] In terms of functional features:

[0095] Adhesion performance was tested according to the method in Example 1, and the adhesion strength of the pigskin was 17.2 kPa.

[0096] Conclusion: The mass of ethylene glycol affects the mechanical and adhesive properties of the gel. The stress and compressive strength of the gel initially increase and then decrease with increasing ethylene glycol mass. This is because while increasing ethylene glycol mass enhances the gel's flexibility, excessive amounts lead to insufficient strength, resulting in reduced stress. Furthermore, the adhesive strength of the gel also initially increases and then decreases with increasing ethylene glycol mass. This is because an appropriate amount of ethylene glycol strengthens the internal network of the gel, thereby improving the adhesive properties of the eutectic gel; however, excessive ethylene glycol reduces dynamic adhesive stability. Therefore, a suitable mass of ethylene glycol improves the mechanical strength and adhesive properties of the eutectic gel.

[0097] Example 8

[0098] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that the amount of pretreatment solution PL4 in step (5) is adjusted from 0.5g to 0.3g; other steps and conditions are the same as in Example 1. A transparent bio-based gel (PL4) is obtained. 4-0.3 EG 0.5 ).

[0099] The PL obtained in this embodiment 4-0.3 EG 0.5 The eutectic gel was subjected to systematic testing.

[0100] In terms of mechanical properties: such as Figure 1 As shown, the tensile strain reaches 538%, the tensile stress is 512 kPa, the compressive strength reaches 546 kPa, and the toughness is as high as 1298 kJ / m. 3 Young's modulus is 81 kPa.

[0101] In terms of functional features:

[0102] Adhesion performance was tested according to the method in Example 1, and the adhesion strength of the pigskin was 8.3 kPa.

[0103] Conclusion: The reduced amount of pretreatment solution indicates insufficient lignin content, which serves as a rigid filler and physical cross-linking point, leading to a decrease in the mechanical toughness and adhesion properties of the gel.

[0104] Example 9

[0105] A method for integrated deconstruction and gel construction of moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that the amount of ethylene glycol in step (5) is adjusted from 0.5g to 0.3g; other steps and conditions are the same as in Example 1. A transparent bio-based gel (PL) is obtained. 4-0.5 EG 0.3 ).

[0106] The PL obtained in this embodiment 4-0.5EG 0.3 The eutectic gel was subjected to systematic testing.

[0107] In terms of mechanical properties: such as Figure 1 As shown, the tensile strain reaches 433%, the tensile stress is 519 kPa, the compressive strength is 584 kPa, and the toughness is as high as 1122 kJ / m. 3 Young's modulus is 80 kPa.

[0108] In terms of functional features:

[0109] Adhesion properties were tested according to the method in Example 1, and the adhesion strength of the pigskin was 6.9 kPa.

[0110] Conclusion: The reduction of ethylene glycol significantly decreased the hydrogen bonding interactions and plasticizing effect within the gel, thereby reducing the cohesive strength and adhesion properties of the gel.

[0111] Example 10

[0112] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that the amount of ethylene glycol in step (5) is adjusted from 0.5g to 1g; other steps and conditions are the same as in Example 1. A transparent bio-based gel (PL) is obtained. 4-0.5 EG1).

[0113] The PL obtained in this embodiment 4-0.5 Systematic testing was conducted on EG1 eutectic gel.

[0114] In terms of mechanical properties: such as Figure 1 As shown, the tensile strain reaches 622%, the tensile stress is 244 kPa, the compressive strength reaches 473 kPa, and the toughness is as high as 751 kJ / m. 3 Young's modulus is 31 kPa.

[0115] In terms of functional features:

[0116] Adhesion performance was tested according to the method in Example 1, and the adhesion strength of the pigskin was 8.3 kPa.

[0117] Conclusion: The mass of ethylene glycol affects the mechanical and adhesive properties of the gel. The stress and compressive strength of the gel initially increase and then decrease with increasing ethylene glycol mass. This is because while increasing ethylene glycol mass enhances the gel's flexibility, excessive amounts lead to insufficient strength, resulting in reduced stress. Furthermore, the adhesive strength of the gel also initially increases and then decreases with increasing ethylene glycol mass. This is because an appropriate amount of ethylene glycol strengthens the internal network of the gel, thereby improving the adhesive properties of the eutectic gel; however, excessive ethylene glycol reduces dynamic adhesive stability. Therefore, a suitable mass of ethylene glycol improves the mechanical strength and adhesive properties of the eutectic gel.

[0118] Comparative Example 1

[0119] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that p-toluenesulfonic acid (PTSA) is not added in step (2); the other steps and conditions are the same as in Example 1.

[0120] The solid residue obtained in step (4) was analyzed and found to have a solid residue rate of 68.29%, a lignin removal rate of 46.50%, and a hemicellulose removal rate of 52.12%.

[0121] X-ray diffraction analysis of the solid residue obtained in step (4) showed that its crystallinity was 47.73%, which was slightly higher than that of the untreated bamboo raw material (44.70%).

[0122] The solid residue obtained in step (4) was subjected to a semi-synchronous saccharification and fermentation experiment according to the method of Example 1, and the ethanol yield was 58.61% after 72 hours.

[0123] Conclusion: Without the PTSA catalytic component, the deconstruction efficiency of the DES system is significantly reduced, making it difficult to achieve efficient separation and conversion of each component.

[0124] Comparative Example 2

[0125] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that: in step (2), the same molar amount of choline chloride is used instead of TBAC; other steps and conditions are the same as in Example 1.

[0126] The composition of the solid residue obtained in step (4) was analyzed. The solid residue rate was 61.50%, the lignin removal rate was 52.42%, and the hemicellulose removal rate was 60.18%.

[0127] X-ray diffraction analysis of the solid residue obtained in step (4) showed that its crystallinity was 53.77%, which was higher than that of the untreated bamboo raw material (44.70%).

[0128] The solid residue obtained in step (4) was subjected to a semi-synchronous saccharification and fermentation experiment according to the method of Example 1, and the ethanol yield was 67.61% after 72 hours.

[0129] The gel obtained in this comparative example was systematically tested, and its overall performance was unsatisfactory.

[0130] In terms of mechanical properties: the tensile strain is only 142%, the tensile stress is 68 kPa, the compressive strength is 205 kPa, and the toughness is 384 kJ / m³.

[0131] In terms of functional features:

[0132] The self-healing performance was tested according to the method in Example 1. The self-healing ability was limited, with a healing efficiency of only 48% after 72 hours.

[0133] The wide temperature range adaptability was tested according to the method in Example 1. The low temperature adaptability was insufficient, and it became significantly hardened and brittle at -20°C.

[0134] The UV shielding performance was tested according to the method in Example 1. The UV shielding performance was poor, with an average transmittance of >35% in the 200-360 nm band.

[0135] The adhesion properties were tested according to the method in Example 1. The adhesion properties were weak, with a pigskin adhesion strength of 4.92 kPa.

[0136] Conclusion: Replacing TBAC with choline chloride significantly reduced the destructive ability of the DES system, demonstrating the irreplaceable role of TBAC in constructing efficient destructive systems. The underlying reason for the poor overall performance of this eutectic gel can be attributed to the chemical composition and structural defects of the precursor treatment solution. Specifically, the insufficient content of lignin and hemicellulose in the treatment solution, and their failure to form effective chemical crosslinks with the gel matrix, are key factors leading to the comprehensive limitation of the material's mechanical properties, functional characteristics, and application performance.

[0137] Comparative Example 3

[0138] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that p-toluenesulfonic acid (PTSA) is not added in step (2), but the same molar amount of PTSA is added only in step (5); the other steps and conditions are the same as in Example 1.

[0139] The gel has a tensile strain of 210% and a toughness of only 320 KJ / m³.

[0140] Conclusion: PTSA must be included in the pretreatment as a component of DES in order to achieve efficient targeted breaking of LCC bonds.

[0141] Comparative Example 4

[0142] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that zinc chloride is not added in step (5); the other steps and conditions are the same as in Example 1.

[0143] Systematic testing of the gel obtained in this comparative example revealed unsatisfactory overall performance. The gel exhibited a tensile strain of 142% and a tensile stress of 68 kPa; its toughness was 384 kJ / m³; and it significantly hardened and became brittle at -20°C. The gel possessed only basic mechanical properties, and its conductivity would be less than 1 mS / cm, making it unsuitable for sensitive sensing applications.

[0144] Comparative Example 5

[0145] An integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system is described in Example 1, except that: in step (5), prepolymerization is carried out at 40 °C; other steps and conditions are the same as in Example 1.

[0146] Systematic testing of the gel obtained in this comparative example revealed unsatisfactory overall performance. The macromolecules in the pretreatment solution could not be uniformly dispersed, leading to microscopic defects inside the cured gel and a reduction in tensile strength of more than 40%.

[0147] Experimental Example 1

[0148] Sensor testing:

[0149] The change in relative resistance under specific behavior was measured using a digital source meter (Keithley 2450, USA). The change in relative resistance of the sample was calculated using the formula: ΔR = (R - R0) × 100%, where R0 and R are the initial resistance and the real-time resistance under specific strain, respectively. The test samples were eutectic gels prepared in Example 1 and Comparative Example 2.

[0150] The eutectic gel prepared in Example 1 was subjected to tensile cycles at different strains (25-100%) and a fixed tensile speed (60 mm / min) to test its sensing performance. The test results are as follows: Figure 2 (a) is shown. PL 4-0.5 EG 0.5 Eutectic sensors can detect minute deformations (25%~100%), thanks to the excellent flexibility and elasticity of eutectic gels.

[0151] The eutectic gel prepared in Example 1 was subjected to tensile cycles at a fixed strain (100%) and different tensile speeds (100~400 mm / min) to test its sensing performance. The test results are as follows: Figure 2 As shown in (b), at tensile rates of 100~400 mm / min, the resistance change and strain are well synchronized, with no hysteresis or signal fluctuation.

[0152] The eutectic gel prepared in Example 1 was subjected to 400 tensile cycles at a fixed strain (100%) and a fixed tensile speed (400 mm / min). The test results are as follows: Figure 2 As shown in (c)-(e). PL 4-0.5 EG 0.5The eutectic gel sensor exhibits significant cyclic stability and fatigue resistance, indicating its suitability for long-term continuous monitoring environments. After 400 cycles, its performance retention rate is >95%, demonstrating excellent long-term cyclic stability. In contrast, the eutectic gel prepared in Comparative Example 2 retains approximately 79% of its performance after 400 cycles, showing inferior long-term cyclic stability compared to this invention.

[0153] The response time of the eutectic gel prepared in Example 1 was tested. A momentary small strain (10% stretch) was applied to the eutectic gel using a universal tensile testing machine, while its resistance change was monitored in real time using a digital multimeter. The time required from the application of strain to the sensor's electrical signal reaching a stable change value was measured. Figure 2 As shown in (f), Example 1 exhibits excellent real-time sensing capability with a response time of only 1.16 s. This data is significantly better than the 3.4 s of Comparative Example 2. The results indicate that the eutectic gel prepared in this invention possesses timely responsiveness and excellent sensitivity, enabling more accurate and real-time feedback of minute deformation signals in human activity monitoring or wearable electronic devices, demonstrating superior strain sensing characteristics.

[0154] The eutectic gel prepared in Example 1 was attached to the surfaces of the wrist, elbow, and fingers, and its sensing performance during wrist, elbow, and finger movements was tested. Figure 3 As shown in (a)-(c), PL 4-0.5 EG 0.5 Eutectic gels can detect the resistance signals generated by strain during wrist, elbow, and finger movements. By monitoring changes in resistance signals in real time, eutectic gel sensors can accurately identify the type of movement by detecting differences in joint bending deformation caused by different human activities and combining signal analysis and pattern recognition technologies.

[0155] The relationship between tensile strain and relative electrical resistance of the eutectic gel prepared in Example 1 is as follows: Figure 3 As shown in (d), the sensitivity factor is 1.31, exhibiting excellent strain sensing characteristics. In contrast, the sensitivity factor of the eutectic gel prepared in Comparative Example 2 is 1.05, indicating lower sensitivity than that of the present invention.

[0156] The eutectic gel prepared in Example 1 was applied to the knee surface, and its sensing performance was tested during running and walking. Figure 3 (e)-(f) shown, PL 4-0.5 EG 0.5 Eutectic gels can monitor the flexion and extension of the knee joint in real time during running and walking, and simultaneously capture its amplitude and frequency characteristics.

[0157] These properties indicate that this gel material has significant application potential in cutting-edge fields such as flexible electronics, biomedicine, and intelligent sensing.

[0158] Experimental Example 2

[0159] The multi-channel physiological signal acquisition system is also used to record electrocardiogram (ECG) and electromyogram (EMG) signals under specific behaviors. The PL prepared in Example 1... 4-0.5 EG 0.5 Bioelectrodes made of eutectic gel are fixed to human skin and joints, and changes in human physiological signals are observed through a signal acquisition system.

[0160] PL 4-0.5 EG 0.5 Bioelectrodes were fixed to the arm to test electromyographic signals under relaxed and different grip strength conditions. Figure 4 As shown in (a)-(b), this system can clearly distinguish between the relaxation and tension phases of muscles, and the bioelectrode can be stably applied to the high-precision acquisition of electromyographic signals.

[0161] PL 4-0.5 EG 0.5 Bioelectrodes are attached to the surface of the human body to monitor electrocardiogram (ECG) signals. Because atrial activation signals are weak (low P wave amplitude), traditional electrodes struggle to accurately detect them. However, if... Figure 4 From (c) to (e), we can see that PL 4-0.5 EG 0.5 The electrode can record ECG waveforms completely (including P, Q, R, S and T waves), proving that the electrode material has high sensitivity to weak physiological signals and can be stably applied to high-precision acquisition of ECG signals.

[0162] PL4- 0.5 EG 0.5 Bioelectrodes are fixed to the carotid artery to test carotid artery signals, such as... Figure 4 (f)-(g) successfully acquired the dynamic signal of the carotid artery, indicating that the bioelectrode can be stably applied to the high-precision acquisition of pulse signals, providing a reliable tool for multimodal physiological monitoring of the human body.

[0163] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for integrated deconstruction and gel construction of moso bamboo based on a catalytic ternary eutectic solvent system, comprising the following steps: (1) Mix bamboo powder with a catalytic ternary eutectic solvent, pretreat, and separate solid and liquid to obtain pretreated liquid and solid residue; (2) After washing and drying, the solid residue is fermented by semi-synchronous saccharification to obtain bioethanol; (3) Mix the pretreatment liquid, acrylic acid, ethylene glycol, zinc chloride, crosslinking agent and photoinitiator, prepolymerize and cure with ultraviolet light to obtain eutectic gel.

2. The integrated method for deconstruction and gel construction of moso bamboo based on a catalytic ternary eutectic solvent system according to claim 1, characterized in that, In step (1), the preparation method of the bamboo powder includes the following steps: bamboo is washed, dried, sliced, crushed, screened and dried to obtain bamboo powder with a particle size of 40-60 mesh.

3. The integrated method for deconstruction and gel construction of moso bamboo based on a catalytic ternary eutectic solvent system according to claim 1, characterized in that, In step (1), the preparation method of the catalytic ternary eutectic solvent includes the following steps: mixing tetrabutylammonium chloride (TBAC), lactic acid (LA) and p-toluenesulfonic acid (PTSA), and reacting them to obtain the catalytic ternary eutectic solvent.

4. The integrated method for deconstruction and gel construction of moso bamboo based on a catalytic ternary eutectic solvent system according to claim 3, characterized in that, The molar ratio of tetrabutylammonium chloride (TBAC), lactic acid (LA), and p-toluenesulfonic acid (PTSA) is 1:2:0.06-0.1; preferably, the reaction temperature is 50-80℃, the reaction time is 30-60 min, and the reaction is carried out under stirring conditions.

5. The integrated method for deconstructing and gelling moso bamboo based on a catalytic ternary eutectic solvent system according to claim 1, characterized in that, In step (1), the mass ratio of bamboo powder to catalytic ternary eutectic solvent is 1:10-20.

6. The integrated method for deconstruction and gel construction of moso bamboo based on a catalytic ternary eutectic solvent system according to claim 1, characterized in that, In step (1), the pretreatment temperature is 60-100 ℃, the pretreatment time is 10-30 minutes, and the pretreatment is carried out under stirring conditions.

7. The integrated method for deconstruction and gel construction of moso bamboo based on a catalytic ternary eutectic solvent system according to claim 1, characterized in that, In step (3), the mass ratio of pretreatment liquid to acrylic acid is 0.3-1:1-4; the mass ratio of acrylic acid, ethylene glycol and zinc chloride is 1-4:0.3-1:0.4-0.6; and the mass ratio of acrylic acid, crosslinking agent and photoinitiator is 1-4:0.4-0.8:0.01-0.

05.

8. The integrated method for deconstruction and gel construction of moso bamboo based on a catalytic ternary eutectic solvent system according to claim 1, characterized in that, Step (3) includes one or more of the following conditions: i. The crosslinking agent is polyethylene glycol diacrylate (PEGDA). ii. The photoinitiator is 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone; iii. The prepolymerization reaction conditions are as follows: stir at 70-80℃ for 2-4 hours until a homogeneous prepolymer solution is formed; iv. UV curing time is 5-20 minutes.

9. A eutectic gel prepared by the method according to any one of claims 1-8.

10. The application of the eutectic gel as described in claim 9 in flexible electronics, biomedical or smart sensor devices.

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