Fluorine-free superhydrophobic surfaces, methods for their manufacture and use

Abstract

The present disclosure relates to a superhydrophobic material and / or surface comprising a shrinkable polymer substrate and at least one polysiloxane layer, the material and / or surface comprising microscale wrinkles and nanoscale features forming a hierarchical structure, the method of manufacture and use of which are also disclosed herein.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 260,371, filed August 18, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to surface engineering, and in particular to fluorine-free superhydrophobic surfaces, and methods of making and using same. [Background technology]

[0003] Surface contamination plays a major role in the transmission and spread of pathogens. Whether in healthcare, food supply chains, or public spaces, the risk of pathogens being transmitted through fomites has been widely demonstrated. In healthcare systems, healthcare-associated infections (HAIs) are a major risk. For example, a serious threat is posed by carbapenem-resistant Enterobacteriaceae (CRE), a family of pathogens resistant to almost all antibiotics. It is estimated that the transmission of pathogens by healthcare workers, either through direct contact with infected patients or indirectly by touching contaminated surfaces in patient areas, accounts for 20-40% of HAIs. This highlights the importance of designing anti-adhesive surfaces that resist contamination or biofouling. Although many efforts have been made to address this issue, the proposed solutions face numerous limitations, including very costly manufacturing methods, environmentally unfriendly materials, or incompatibility with high-contact applications.

[0004] To achieve anti-adhesion, researchers' goal is to create superhydrophobic surfaces characterized by contact angles >150° and sliding angles <10°. Strategies for fabrication are often biomimetic, such as physical modifications to impart roughness inspired by the multiscale textures found on lotus leaves and butterfly wings. This increase in roughness provides the basis for the Cassie-Baxter or Wenzel wetting regime. Conventional techniques for achieving roughness include etching, electrochemical deposition, templating, spray coating, application of nanoparticles such as gold or silica, and sol-gel processes. To faithfully reproduce the lotus effect, researchers typically use a series of these modifications to introduce hierarchical structures. 1~3 By implementing a multi-step approach, both micro- and nano-scale features are established on the surface, which can be used for biofouling prevention. 1,4,5 Although these techniques have proven successful, it is often difficult to produce these surfaces on a large scale due to manufacturing constraints and the prohibitive cost of the reagents involved.

[0005] As an alternative, chemical modification can be used to reduce the surface free energy (SFE) of the fabricated surfaces by using techniques such as chemical vapor deposition (CVD), liquid phase deposition (LPD), plasma, self-assembly, and solution immersion. These approaches often utilize silane molecules to form single or multilayer coatings that reduce the SFE and can be combined with physical modification to exhibit superhydrophobicity. The silane molecules used have reactive functional groups such as chlorine, which facilitate self-assembled coatings by surface-initiated condensation reactions, allowing ease and control of fabrication. In many cases, fluorocarbons such as those found in trichloro(1H,1H,2H,2H-perfluorooctyl)silane (TPFS) and 1H,1H,2H,2H-perfluorodecyltrichlorosilane (PFDTS) constitute the backbone of these chemicals. However, these chemicals carry potentially serious environmental risks. Long-term studies have demonstrated that long-chain (C9-C20 Due to the documented toxic effects in mammals of fluorocarbons and their precursors, as well as the persistence of these and shorter chain fluorocarbons in the environment leading to bioaccumulation in plants, animals, and humans, research has turned towards more environmentally friendly remediation strategies.

[0006] The growth of polysiloxane nanostructures resulting in superhydrophobicity was first investigated by Artus et al. in 2006 and offers a more environmentally friendly approach. 6 By utilizing trichlorosilane molecules with short, one or two carbon chains and no fluorine groups, coatings were achieved through both CVD and LPD. 7~9 These structures represent a promising route for inducing surface roughness, leading to superhydrophobicity and self-cleaning properties, which have been more recently established for three-carbon chain trichlorosilanes as well. 10,11 There are few reports on the pathogen adhesion prevention properties of these surfaces, which may be due to the conflicting results seen. For example, when coated on glass, polysiloxane nanofilament and rod structures behaved differently in static versus dynamic conditions based on the type of bacteria tested. 12 Studies have demonstrated that effectiveness also varies with the structure of the coating and is dependent on humidity levels, temperature, and substrate.

[0007] Lubricants have been used to address the pathogen adhesion prevention challenges faced by polysiloxane structured surfaces. When combined with a silicone oil lubricant layer to mimic the slippery properties of the pouchelia plant, polysiloxane nanofilaments have been shown to prevent bacterial adhesion and inhibit thrombosis on medical devices such as catheters and splints. Slippery liquid-infused surfaces (LIS) are an outstanding engineered surface modification method with self-cleaning properties. Lubricants are added to chemically or structurally modified surfaces that are designed to retain a lubricant layer. LIS have demonstrated biofouling prevention in many applications in confined spaces or under flow with bacteria, viruses, and complex biological fluids. However, these surfaces are limited by the nature of liquid infusion, as direct contact with the surface would transfer residual lubricant and therefore cannot be used on high-touch surfaces. In addition, many of the lubricants used are highly volatile, making them impractical to perform on outdoor surfaces. Summary of the Invention

[0008] The present disclosure provides a material comprising a shrinkable polymer substrate and at least one polysiloxane layer on a surface of the substrate, the material comprising microscale wrinkles and nanoscale features forming a hierarchical structure on a surface of the material, the material exhibiting superhydrophobicity.

[0009] In some embodiments, the material comprises at least one polysiloxane layer on each of a plurality of surfaces of the substrate.

[0010] In some embodiments, the shrinkable polymer substrate comprises polystyrene, polyolefins, polyethylene, polypropylene, and other shrinkable polymers, or combinations and copolymers thereof.

[0011] In some embodiments, the shrinkable polymeric substrate is a polyolefin.

[0012] In some embodiments, the shrinkable polymeric substrate is biaxially stretched.

[0013] In some embodiments, the nanoscale features comprise filament-shaped and / or rod-shaped structures.

[0014] In some embodiments, the at least one polysiloxane layer forms the nanoscale features.

[0015] In some embodiments, the at least one polysiloxane layer is formed using a silane.

[0016] In some embodiments, the at least one polysiloxane layer is formed using one or more compounds of formula II. [ka] [In the formula, R 1 , R 2 , and R 3 are each independently a hydrolyzable group, R 4 is C 1~6 It is alkyl.

[0017] In some embodiments, the at least one polysiloxane layer is formed using n-propyltrichlorosilane.

[0018] In some embodiments, the at least one polysiloxane layer is not formed using a fluorosilane.

[0019] In some embodiments, the material has a static water contact angle of greater than about 150°, about 151°, about 152°, about 153°, about 155°, about 165°, about 170°, or about 175°.

[0020] In some embodiments, the material has a water slide angle of less than about 5°, In some embodiments, the material has a water slide angle of less than about 1°.

[0021] In some embodiments, the material has anti-bacterial or anti-fouling properties.

[0022] In some embodiments, the material exhibits anti-fouling properties to biological fluids.

[0023] In some embodiments, the material exhibits blood-repellent properties.

[0024] In some embodiments, the material exhibits anti-fouling properties against liquids containing biological species.

[0025] In some embodiments, the material exhibits anti-adhesive properties against bacteria and biofilm formation.

[0026] The present disclosure also provides devices or articles comprising the materials disclosed herein.

[0027] In some embodiments, the material is present on a surface of the device or article, hi some embodiments, the material forms a surface of the device or article.

[0028] The present disclosure also provides a method for producing a material having a hierarchically structured surface, the method comprising: a) providing a shrinkable polymeric substrate; b) activating a surface layer of said substrate by oxidation; c) depositing at least one polysiloxane layer on said activated surface layer at a substantially constant relative humidity; and d) treating said substrate under conditions to form microscale wrinkles and nanoscale features to obtain said material; wherein the material exhibits superhydrophobicity.

[0029] The present disclosure also provides a method for producing a material having a hierarchically structured surface, the method comprising: a) activating a surface layer of a shrinkable polymer substrate by oxidation; b) depositing at least one polysiloxane layer on said activated surface layer at a substantially constant relative humidity; and c) treating said substrate under conditions to form microscale wrinkles and nanoscale features to obtain said material; wherein the material exhibits superhydrophobicity.

[0030] According to another aspect of the present disclosure, there is provided herein a method for producing a material having a hierarchically structured surface, the method comprising: a) activating the shrinkable polymer substrate by oxidation; b) depositing at least one polysiloxane layer onto said shrinkable polymeric substrate at a substantially constant relative humidity; and c) treating said substrate under conditions to form microscale wrinkles and nanoscale features to obtain said material; wherein the material exhibits superhydrophobicity.

[0031] In some embodiments, activating a surface layer of the substrate comprises introducing hydroxyl groups into or onto the substrate.

[0032] In some embodiments, activating the surface layer of the substrate comprises a plasma treatment.

[0033] In some embodiments, the plasma treatment is for a time period from about 30 seconds to about 10 minutes, or from about 2 minutes to about 7 minutes, or from about 3 minutes to about 5 minutes.

[0034] In some embodiments, the shrinkable polymer substrate provided in step a) is biaxially stretched. In some embodiments, the method further comprises biaxially stretching the shrinkable polymer substrate. In some embodiments, the biaxial stretching of the shrinkable polymer substrate is prior to the activation.

[0035] In some embodiments, the shrinkable polymer substrate comprises polystyrene, polyolefins, polyethylene, polypropylene, and other shrinkable polymers, or combinations and copolymers thereof, hi some embodiments, the shrinkable polymer substrate is a polyolefin.

[0036] In some embodiments, the relative humidity is substantially maintained between about 45% and about 65%, or between about 50% and about 60%, or about 55%.

[0037] In some embodiments, the relative humidity is substantially maintained for about 4 hours to about 30 hours, or about 5 hours to about 24 hours, or about 6 hours. In some embodiments, the relative humidity is substantially maintained for the time period during which the at least one polysiloxane layer is deposited. In some embodiments, the at least one polysiloxane layer is formed using n-propyltrichlorosilane.

[0038] In some embodiments, the micro-scale wrinkles and nano-scale features are formed by heat shrinking the substrate.

[0039] Other features and advantages of the present disclosure will become apparent from the following detailed description. However, it should be understood that the detailed description and specific examples, while showing embodiments of the present disclosure, are given for illustrative purposes only, and the claims should not be limited by these embodiments, but should be accorded the broadest interpretation consistent with the entire specification.

[0040] Certain embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. [Brief description of the drawings]

[0041] [Figure 1]FIG. 1 shows the hierarchical superhydrophobic n-PTCS surface in an exemplary embodiment of the present disclosure: a) Fabrication process using a customized humidity chamber; b) SEM images of planar and hierarchical samples at ideal incubation time of 6 hours (scale bars represent 40 μm in left image, 100 μm in right image, and 4 μm in both inset images); c) Side-SEM image of the hierarchical surface shown in b) - the untreated end of the sample was imaged using a 45° tilted stub and a 45° tilt of the stub to obtain the side-view image (scale bar represents 100 μm). [Diagram 2] FIG. 2 shows a comparison of contact angle and sliding angle for 3 and 5 minutes of plasma treatment in an exemplary embodiment of the present disclosure (error bars indicate standard deviation for contact angle). [Diagram 3] FIG. 3 shows characterization and optimization of hierarchical PO surfaces in an exemplary embodiment of the present disclosure: a) Optimization of incubation with n-PTCS characterized using contact angle and sliding angle data - contact angle measurements were performed using 2 μL droplets while sliding angle measurements were performed using 5 μL droplets unless otherwise noted (error bars represent standard deviation calculated over a minimum of three replicate measurements); b) Time-lapse images of a water droplet bouncing on a hierarchical surface - A 5 μL water droplet, when dropped from a height of approximately 10 mm, exhibits two bounces with decreasing height; c) Temperature stability testing of hierarchical n-PTCS surfaces stored at -20°C and 37°C for 24 hours, with contact angle and sliding angle measurements taken before and after storage to assess performance; d) Ethanol stability of hierarchical n-PTCS immersed in 100% ethanol for 1.5 hours, with contact angle measurements taken before and after incubation; e) Sonication stability testing in ethanol using contact angle data for hierarchical surfaces subjected to a series of sonication treatments in ethanol; f) Long-term stability of surfaces stored at room temperature in Petri dishes was tested 3, 4, and 5 months after manufacture, with no change in contact angle and sliding angle observed. [Figure 4]FIG. 4 shows SEM images of flat and contracted samples at various incubation times in an exemplary embodiment of the present disclosure (scale bars are 10 μm in the large image and 1 μm in the inset image). [Diagram 5] FIG. 5 shows the characterization of contact angles and sliding angles of flat and shrink samples with silicone oils of various densities in accordance with an exemplary embodiment of the present disclosure. [Figure 6] FIG. 6 shows the evaluation of blood adhesion resistance of layered n-PTCS surfaces in an exemplary embodiment of the present disclosure: a) Summary of comparison of contact angle and sliding angle measurements for water and blood; b) Optical images of residues left by 5 μL droplets of citrated human whole blood droplets introduced to the surface for the indicated times; c) Quantitative evaluation of blood drop staining of sample images shown in b) evaluated using ImageJ to obtain integrated concentration values ​​- significant reduction was calculated using two-way ANOVA test and demonstrated across multiple groups, here indicated as ** (P=0.01), *** (P=0.001), and **** (P=0.0001). Error bars represent standard deviation; d) Relative absorbance values ​​from whole blood staining normalized to the planar PO of the control condition - Optical images of sample surfaces are shown above each condition on the plot. Significance was tested with one-way ANOVA, here indicated as ** (P=0.01), *** (P=0.001), and **** (P=0.0001). [Figure 7]Figure 7 shows the evaluation of the bacterial adhesion prevention of hierarchical n-PTCS surfaces in an exemplary embodiment of the present disclosure: a) Fluorescence images of the surfaces after bacterial transfer from the counter stamp, using surfaces stamped with E. coli K-12 tagged with green fluorescent protein, captured using an Amersham Typhoon imaging system; b) Quantitative evaluation of the fluorescence images using intensity / area (values ​​were calculated using ImageJ software); c) Direct quantification of bacteria transferred from the counter stamp from seeding bacterial samples from each condition and growing them overnight (plots use logarithmic scale) - error bars represent standard error of the mean. Significance was evaluated using one-way ANOVA test and is indicated here with ** (P=0.01) and *** (P=0.001). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] I. Definition Unless otherwise indicated, the definitions and embodiments set forth in this and other sections are intended to be applicable to all embodiments and aspects of the disclosure described herein where they are appropriate, as would be understood by one of ordinary skill in the art. 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.

[0043] In understanding the scope of the present disclosure, the term "comprising" and its derivatives, as used herein, are intended to be open-ended terms that specify the presence of the stated features, elements, components, groups, integers, and / or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers, and / or steps. The above also applies to words of similar meaning, such as the terms "including," "having," and their derivatives. The term "consisting" and its derivatives, as used herein, are intended to be open-ended terms that specify the presence of the stated features, elements, components, groups, integers, and / or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers, and / or steps. The term "consisting essentially of," as used herein, is intended to define the presence of recited features, elements, components, groups, integers, and / or steps, as well as the presence of elements, components, groups, integers, and / or steps that do not materially affect the basic and novel characteristic(s) of the features, elements, components, groups, integers, and / or steps.

[0044] Terms of degree such as "substantially," "about," and "approximately," as used herein, refer to a reasonable amount of deviation from the modified term such that the end result is not significantly altered. These terms of degree should be interpreted as including at least ±5% deviation from the modified term, if this deviation does not negate the meaning of the word it modifies. In addition, all ranges given herein include the endpoints of the range and any intermediate points of the range, whether or not expressly stated.

[0045] As used in this disclosure, the singular forms "a," "an," and "the" include plural references unless the content clearly dictates otherwise.

[0046] In embodiments that include an "additional" or "second" component, the second component, as that term is used herein, is chemically distinct from the other components or the first component. A "third" component is distinct from the other components, the first component, and the second component, and further recited or "additional" components are similarly distinct.

[0047] The term "and / or" as used herein means that the listed items are present or utilized either individually or in any combination. In effect, the term means that "at least one" or "one or more" of the listed items are present or utilized.

[0048] The abbreviation "e.g., " comes from the Latin exempli gratia, and is used herein to indicate non-limiting examples. Thus, the abbreviation "e.g., " is synonymous with the term "for example." The word "or" is intended to include "and" unless the context clearly indicates otherwise.

[0049] The term "room temperature" as used herein means a temperature within the range of about 20°C to about 25°C.

[0050] The term "crisping" as used herein means any process for creating wrinkles in a material.

[0051] The term "wrinkles" as used herein means micro- to nano-scale folds.

[0052] The term "hierarchical structure" as used herein refers to both microscale and nanoscale structural features. For example, a hierarchical structure on a surface of a material refers to microscale and nanoscale structural features on the surface of the material.

[0053] The term "superhydrophobic" as used herein with respect to materials means a material that exhibits extremely hydrophobic properties (low wettability to water and other polar liquids). Superhydrophobic materials, such as those with very high water contact angles, such as greater than 150°, are often considered "self-cleaning" materials because polar contaminants typically bead up and roll off the surface.

[0054] The terms "shape memory polymer," "shrinkable polymer," and "heat shrinkable polymer," as used herein, refer to pre-stretched polymeric materials.

[0055] The term "alkyl," as used herein, whether used alone or as part of another group, refers to a saturated straight or branched chain alkyl group, i.e., a saturated carbon chain containing a substituent at one of its termini. The number of possible carbon atoms in a referenced alkyl group is indicated by the numerical prefix "C n1~n2 For example, C 1~6 The term alkyl refers to alkyl groups having 1, 2, 3, 4, 5, or 6 carbon atoms.

[0056] The term "halo" as used herein means a halogen atom and includes F, Cl, Br, and I.

[0057] The term "hydroxyl" as used herein refers to the functional group OH.

[0058] The term "suitable" as used herein means that the selection of a particular compound or condition will depend on the specific synthetic operation being performed and the type of molecule(s) being converted, but said selection is well within the skill of one of ordinary skill in the art. All process / method steps described herein should be performed under conditions that allow the reaction to proceed to a sufficient extent to provide the indicated product. One of ordinary skill in the art will understand that all reaction conditions, including, for example, reaction solvent, reaction time, reaction temperature, reaction pressure, reactant ratios, and whether the reaction should be performed under anhydrous or inert atmosphere, can be varied to optimize the yield of the desired product, and it is within the skill of one of ordinary skill in the art to do so.

[0059] It is understood that any element defined herein as included may be expressly excluded, such as any particular compound or method step, whether implicitly or explicitly defined herein, by conditional or negative limitation.

[0060] II. Compositions and Methods of the Disclosure Disclosed herein is a fluorine- or lubricant-free flexible hierarchical surface coating, which is created by using a simple and inexpensive fluorine-free method to fabricate a superhydrophobic anti-biofouling surface with a wrinkled topography that achieves comparable performance to lubricant-infused surfaces. This was achieved by combining nanostructuring of polysiloxanes and wrinkling of thermoplastic polymers to obtain a hierarchical and stable surface.

[0061] In embodiments herein, these hierarchical surfaces were fabricated by growing polysiloxane nanoscale features, such as n-propyltrichlorosilane (n-PTCS) nanostructures via CVD processing on a thin thermoplastic material, such as a shape memory polymer substrate, such as polyolefin (PO), and then heat shrinking to wrinkle the hard n-PTCS nanostructured layer, producing microscale wrinkles with integrated n-PTCS nanostructures.

[0062] The developed surfaces and / or coatings have demonstrated superhydrophobicity for anti-adhesion of liquids and pathogens, as well as anti-biofouling properties without the use of lubricants. These hierarchical surfaces have demonstrated a significant reduction in bacterial transmission, indicating their potential as antimicrobial coatings to mitigate the spread of infectious diseases, as well as a significant reduction in blood staining after incubation with human whole blood, with the advantage of being lubricant-free for use in high-touch and outdoor environments. Thus, the final product is a fluorine-free, flexible, superhydrophobic, anti-biofouling surface with a demonstrated ability to repel bacteria and complex biological fluids such as human whole blood.

[0063] Taking advantage of this simple, low-cost and environmentally safe fabrication method, herein, flexible superhydrophobic hierarchical surfaces with strong anti-fouling properties are fabricated based on their anti-fouling properties against pathogens and their stability in cleaning agents such as ethanol, which can be used in high-touch, outdoor environments in general, as well as in the medical and food industries. The application of these surfaces in longer-term biomedical applications such as catheters and implants, and as cell culture platforms are also possible.

[0064] Thus, provided herein is a material comprising a shrinkable polymer substrate and at least one polysiloxane layer, said material comprising microscale wrinkles and nanoscale features forming a hierarchical structure, and said material exhibiting superhydrophobicity.

[0065] Also provided herein is a material comprising a shrinkable polymer substrate and at least one polysiloxane layer on a surface layer of the substrate, the material comprising microscale wrinkles and nanoscale features forming a hierarchical structure on a surface of the material, and the material exhibits superhydrophobicity.

[0066] In some embodiments, the material comprises at least one polysiloxane layer on each of a plurality of surfaces of the substrate.

[0067] In some embodiments, the shrinkable polymer substrate comprises polystyrene, polyolefins, polyethylene, polypropylene, and other shrinkable polymers, or combinations and copolymers thereof. In some embodiments, the shrinkable polymer substrate is a polyolefin. In some embodiments, the substrate is a thin flexible film of a polyolefin.

[0068] In some embodiments, the shrinkable polymeric substrate is biaxially stretched.

[0069] In some embodiments, the micro-scale wrinkles are created from wrinkling the surface layer of the shrinkable polymer substrate.

[0070] In some embodiments, the nanoscale features comprise filament-shaped and / or rod-shaped structures.

[0071] In some embodiments, the at least one polysiloxane layer forms the nanoscale features.

[0072] In some embodiments, the at least one polysiloxane layer is formed using a silane.

[0073] In some embodiments, the at least one polysiloxane layer is formed using one or more compounds of formula II. [ka] [In the formula, R 1 , R 2 , and R 3 are each independently a hydrolyzable group, X is a single bond, and R 4 is C 1~6 It is alkyl.

[0074] In some embodiments, the at least one polysiloxane layer is formed using one or more compounds of formula II. [ka] [In the formula, R 1 , R 2 , and R 3 are each independently a hydrolyzable group, R 4 is C 1~6 It is alkyl.

[0075] The hydrolyzable group can be any suitable hydrolyzable group, the selection of which can be made by one of ordinary skill in the art. In some embodiments, R, R 2 , and R 3 are independently halo. In some embodiments, R, R 2 , and R 3 are all Cl.

[0076] In some embodiments, R 4 is C 1~6 In some embodiments, R 4 is C 1~3 It is an alkyl.

[0077] In some embodiments, the at least one polysiloxane layer is formed using a silane. Suitable examples of the silane include, but are not limited to, trichloro(methyl)silane, trichloro(ethyl)silane, and / or n-propyltrichlorosilane. In some embodiments, the at least one polysiloxane layer is formed using n-propyltrichlorosilane.

[0078] In some embodiments, the at least one polysiloxane layer is not formed using a fluorosilane.

[0079] In some embodiments, the material has a static water contact angle of greater than about 150°, about 150°, about 151°, about 152°, about 153°, about 155°, about 165°, about 170°, or about 175°. In some embodiments, the material has a static water contact angle of between about 150° and about 165°.

[0080] In some embodiments, the material has a water slide angle of less than about 5°, less than about 4°, less than about 3°, less than about 2°, or less than about 1°, in some embodiments, the material has a water slide angle of less than about 1°.

[0081] In some embodiments, it has been observed that when these materials with hierarchical surfaces are contacted with blood or bacterial contaminants, their superhydrophobicity can be transformed into better biofouling resistance, hi some embodiments, the materials have antibacterial or antifouling properties.

[0082] In some embodiments, the material exhibits anti-adhesive properties to water. In some embodiments, the material exhibits anti-adhesive properties to biological fluids. In some embodiments, the biological fluids are selected from the group consisting of whole blood, plasma, serum, sweat, feces, urine, saliva, tears, vaginal fluid, prostatic fluid, gingival fluid, amniotic fluid, intraocular fluid, cerebrospinal fluid, semen, sputum, peritoneal fluid, pus, nasopharengal fluid, wound exudate, aqueous humor, vitreous fluid, bile, earwax, endolymph, perilymph, gastric fluid, mucus, peritoneal fluid, pleural fluid, sebum, vomit, and combinations thereof.

[0083] In some embodiments, the material exhibits anti-fouling properties against blood. In some embodiments, blood fouling is reduced by about 93%. In some embodiments, blood fouling is determined by incubating the material in blood for about 20 minutes, then placing the material in deionized water and shaking the material in the water for about 30 minutes to allow the blood fouled on the surface to mix into the water, after which the material is removed from the water and the absorbance value of the water is measured to determine the change in the amount of blood (e.g., hemoglobin) present on each surface.

[0084] In some embodiments, the material exhibits anti-fouling properties against liquids containing biological species. In some embodiments, the biological species include microorganisms such as bacteria, fungi, viruses, or diseased cells, parasitized cells, cancer cells, foreign cells, stem cells, and infected cells. In some embodiments, the biological species also included biological species components such as cell organelles, cell fragments, proteins, nucleic acid vesicles, nanoparticles, biofilms, and biofilm components.

[0085] In some embodiments, the material exhibits anti-adhesive properties against bacteria and biofilm formation. In some embodiments, the surface exhibits anti-adhesive properties against bacteria and biofilm formation. In some embodiments, the bacteria is selected from one or more species of Gram-negative bacteria or Gram-positive bacteria. In some embodiments, the bacteria is selected from one or more species of Escherichia coli, Streptococcus species, Helicobacter pylori, Clostridium species, and Neisseria meningitidis. In some embodiments, the bacteria is selected from the group consisting of Escherichia coli, Salmonella typhimurium, Helicobacter pylori, Pseudomonas aerugenosa, Neisseria meningitidis, Klebsiella aerogenes, Shigella sonnei, Brevundimonas diminuta, Hafnia alvei, Yersinia ruckeri, Actinobacillus actinomycetemcomitans, Achromobacter xylosoxidans, Moraxella osloensis, and the like. The gram-negative bacteria is selected from one or more of the following: Acinetobacter osloensis, Acinetobacter lwoffi, and Serratia fonticola.In some embodiments, the bacterium is a gram-positive bacterium selected from one or more of Listeria monocytogenes, Bacillus subtilis, Clostridium difficile, Staphylococcus aureus, Enterococcus faecalis, Streptococcus pyogenes, Mycoplasma capricolum, Streptomyces violaceoruber, Corynebacterium diphtheria, and Nocardia farcinica. In some embodiments, the bacterium is Escherichia coli. In some embodiments, bacterial adhesion is reduced by about 97.5%.

[0086] According to another aspect, a device or article is provided comprising the material described herein. In some embodiments, the device or article is selected from any medical and laboratory device, personal protective equipment, and medical device. In some embodiments, the device or article is selected from a cannula, a connector, a catheter, a catheter, a clamp, a skin hook, a cuff, a retractor, a shunt, a needle, a capillary tube, an endotracheal tube, a ventilator, a ventilator tube, a drug delivery carrier, a syringe, a microscope slide, a plate, a film, a laboratory work surface, a well, a well plate, a petri dish, a tile, a jar, a flask, a beaker, a vial, a test tube, a tube connector, a column, a container, a cuvette, a bottle, a drum, a vat, a tank, a dental tool, a dental implant, a biosensor, a bioelectrode, an endoscope, a mesh, a wound dressing, a vascular graft, and combinations thereof. In some embodiments, the device or article is selected from any article with a high-risk surface in a hospital environment (e.g., surgical and medical equipment), food packaging (e.g., packaging for meat, produce, etc.), high-touch surfaces in public places (e.g., door handles, elevator buttons, etc.), or wearable articles (e.g., gloves, watches, etc.). In some embodiments, the device is a catheter or implant. In some embodiments, the device is used for cell culture.

[0087] In some embodiments, the material is present on a surface of the device or article. In some embodiments, the material is used to modify the surface of a device or article, such as a preformed device or article, including but not limited to any of the devices or articles listed above. In some embodiments, the material forms the surface of the device or article.

[0088] According to another aspect of the present disclosure, there is provided herein a method for producing a material having a hierarchically structured surface, the method comprising: a) obtaining a shrinkable polymeric substrate; b) activating said substrate by oxidation of a surface layer; c) depositing at least one polysiloxane layer on said surface at a substantially constant relative humidity; and d) treating the material to form micro-scale wrinkles; and the resulting surface exhibits superhydrophobicity.

[0089] According to another aspect of the present disclosure, there is provided herein a method for producing a material having a hierarchically structured surface, the method comprising: a) activating the shrinkable polymer substrate by oxidation; b) depositing at least one polysiloxane layer onto said shrinkable polymeric substrate at a substantially constant relative humidity; and c) treating said substrate under conditions to form microscale wrinkles and nanoscale features to obtain said material; wherein the material exhibits superhydrophobicity.

[0090] According to another aspect of the present disclosure, there is provided herein a method for producing a material having a hierarchically structured surface, the method comprising: a) providing a shrinkable polymeric substrate; b) activating a surface layer of said substrate by oxidation; c) depositing at least one polysiloxane layer on said activated surface layer at a substantially constant relative humidity; and d) treating said substrate under conditions to form microscale wrinkles and nanoscale features to obtain said material; wherein the material exhibits superhydrophobicity.

[0091] According to another aspect of the present disclosure, there is provided herein a method for producing a material having a hierarchically structured surface, the method comprising: a) activating a surface layer of a shrinkable polymer substrate by oxidation; b) depositing at least one polysiloxane layer on said activated surface layer at a substantially constant relative humidity; and c) treating said substrate under conditions to form microscale wrinkles and nanoscale features to obtain said material; wherein the material exhibits superhydrophobicity.

[0092] In some embodiments, activating the substrate comprises introducing hydroxyl groups into or onto the substrate.

[0093] In some embodiments, activating the substrate comprises a plasma treatment, hi some embodiments, activating the substrate comprises an oxygen plasma treatment.

[0094] In some embodiments, the plasma treatment is for a time period from about 30 seconds to about 10 minutes, or from about 2 minutes to about 7 minutes, or from about 3 minutes to about 5 minutes.

[0095] In some embodiments, the shrinkable polymer substrate is biaxially stretched. In some embodiments, the method further comprises biaxially stretching the shrinkable polymer substrate prior to activation.

[0096] In some embodiments, the shrinkable polymer substrate comprises polystyrene, polyolefins, polyethylene, polypropylene, and other shrinkable polymers, or combinations and copolymers thereof. Shrinkable polymers include, but are not limited to, polystyrene or polyolefins. For example, the terms "shape memory polymer," "shrinkable polymer," and "heat shrinkable polymer" can refer to a polymer that shrinks by subjecting the polymer to a temperature above its glass transition temperature. In some embodiments, the shrinkable polymer substrate comprises polystyrene, polyolefins, polyethylene, polypropylene, or combinations and copolymers thereof. In some embodiments, the shrinkable polymer substrate is a polyolefin.

[0097] In some embodiments, the relative humidity is substantially maintained between about 45% and about 65%, or between about 50% and about 60%, or about 55%.

[0098] In some embodiments, the relative humidity is substantially maintained for about 4 hours to about 30 hours, or about 5 hours to about 24 hours, or about 6 hours, In some embodiments, the relative humidity is substantially maintained for the time period during which the at least one polysiloxane layer is deposited.

[0099] In some embodiments, the at least one polysiloxane layer is formed using n-propyltrichlorosilane.

[0100] In some embodiments, the wrinkles are formed using a suitable wrinkling process known in the art. In some embodiments, the wrinkling process is any process that creates a microstructure in the material. In some embodiments, the wrinkling process includes exposing a compliant substrate modified with a hard skin layer to an in-plane compressive strain, or when the substrate is subjected to removal of a tensile strain. Wrinkles are formed as a result of a mismatch in the elastic modulus of the hard layer and the deformable substrate. In some embodiments, the microscale wrinkles are formed by heat shrinking the material. In some embodiments, heat shrinking is performed at a temperature of about 100° C. to about 200° C., about 120° C. to about 160° C., or about 140° C. to about 150° C., or about 145° C. In some embodiments, the heat shrinking is performed for about 1 minute to about 15 minutes, or about 5 minutes to about 12 minutes, or about 10 minutes.

[0101] In some embodiments, the method may be used to modify the surface of a device or article, such as a preformed device or article, including but not limited to any of the devices or articles listed above, hi some embodiments, the device or article comprises the shrinkable polymeric substrate.

[0102] In some embodiments, the method further comprises applying the substrate onto a surface of a device or article after depositing the at least one polysiloxane layer on the activated surface layer. In some embodiments, the substrate is wrapped onto at least a portion of the device or article after step c). In some embodiments, step d) is performed after wrapping to form a seal between the device or article and the material.

[0103] In some embodiments, the materials are placed on a wide variety of surfaces, such as high-risk surfaces in hospital environments (e.g., surgical and medical equipment), food packaging (e.g., packaging for meat, produce, etc.), high-touch surfaces in public places (e.g., door handles, elevator buttons, etc.), or wearable articles (e.g., gloves, watches, etc.). EXAMPLES

[0104] The following non-limiting examples illustrate the present application.

[0105] method

[0106] Reagents. n-Propyltrichlorosilane (98%) was purchased from Thermo Fisher Scientific (Whitby, Ontario, Canada). Sodium bromide (99%) and silicone oils of various viscosities (10, 20, 50, 100, 350, and 1000 cSt) were purchased from Sigma-Aldrich (Oakville, Ontario, Canada). Ethanol (absolute) was purchased from Greenfield (Brampton, Ontario, Canada). Deionized water was used to prepare solutions. E. coli K-12 MG1655 transfected with pUA66-GadB green fluorescent protein was kindly provided by Dr. Eric Brown. LB broth powder was purchased from Thermo Fisher Scientific (Whitby, ON). Agar was purchased from Bio-Rad. Kanamycin was purchased from Sigma-Aldrich (Oakville, ON). Human venous whole blood was collected from healthy donors into sodium citrate-containing tubes by qualified phlebotomists. All donors provided written informed consent prior to donation. All procedures were approved by the McMaster University Research Ethics Board.

[0107] Substrate preparation. Polyolefin (Cryovac D-955) was cut to the desired substrate size and shape. Each substrate was washed with deionized water and ethanol, followed by drying with nitrogen gas. The surface of each substrate was activated with hydroxyl groups using oxygen plasma treatment (Plasma Etch PE-100 Benchtop Plasma Etching System, Carson City, Nevada) for 3 or 5 minutes.

[0108] Growth of nanostructures. After plasma treatment, the substrates were coated with n-PTCS nanostructures. First, the samples were placed inside a closed chamber for a humidity stabilization period of 2 hours. The relative humidity was controlled using a supersaturated sodium bromide solution contained in the bottom of the chamber. After the desired RH (approximately 55%) was obtained, n-PTCS was added to the chamber through a closed rubber stopper. Surface-initiated polymerization was allowed to proceed for various times (6 hours, 12 hours, 18 hours, and 24 hours) at room temperature.

[0109] Hierarchical Surface. After coating, some samples were further modified using a heat treatment. The substrate was placed on a silicon wafer in a preheated oven at 145°C for 10 minutes to induce wrinkles, resulting in a hierarchical surface.

[0110] Lubricant-treated surfaces. For testing of the lubricant-treated condition, substrates already coated with n-PTCS nanostructures, some heat-shrunk and some not, were further treated with silicone oils of various viscosities (10, 20, 50, 100, 350, and 100 cSt). Lubricant was added to the substrates and incubated for 2 hours, followed by holding the substrates vertically for 24 hours to remove excess oil. To minimize further loss of lubricant, the surfaces in this condition were tested immediately after preparation.

[0111] Sliding and Contact Angle Measurements. Preliminary properties of each sample were analyzed using water contact angle and sliding angle measurements to determine the wettability of the surface. Contact angle measurements of samples were performed using a drop shape analyzer (Kruss DSA30S, Matthews, North Carolina). A 2 μL drop of water was dispensed from a needle and the sessile contact angle was measured using the instrument software. Sliding angle measurements were performed using a calibrated digital goniometer level (ROK, Exeter, UK). A 5 μL drop was pipetted onto the sample and the level was slowly tilted until the drop began to move. For high performance surfaces, the drop often slid across the surface and no tilt was required to move it. Such samples were assigned a sliding angle of 1°. If the drop did not move beyond 90°, a sliding angle of 90° was assigned. For both contact angle and sliding angle, measurements were repeated a minimum of three times across the surface and the mean ± standard deviation was reported.

[0112] Scanning electron microscopy (SEM). To visualize the nanostructures formed on the surface, an electron microscope (JEOL JSM-7000F, FEI Magellan 400) had to be used. Samples were prepared as described above, cut to size, mounted on stubs using carbon tape and nickel paste, and subsequently coated with 10 nm of platinum using a sputter coater (Polaron model E1500, Polaron Equipment Ltd., Watford, Hertfordshire). SEM images were collected from the top view, with the stub tilted at 45°, and also from the side for some samples.

[0113] Stability Testing. Several stability tests were performed on the hierarchical n-PTCS surfaces. To evaluate the effect of temperature, the surfaces were stored at -20°C and 37°C for 24 hours. Contact angle and sliding angle measurements were performed before and after incubation. The ethanol resistance ability of the surfaces was tested by incubating the surfaces in 100% ethanol for 1.5 hours and the performance was evaluated using contact angle. To check the stability of the surfaces with ethanol washing, the hierarchical surfaces were subjected to a series of washings in ethanol with ultrasound. 7 mL of ethanol was added to a 15 mL Falcon tube and the hierarchical surfaces were immersed. After ultrasonic treatment for 5, 10 and 15 minutes, contact angle and sliding angle measurements were performed. ASTM scratch testing was performed using an Elcometer 1542 Crosshatch Adhesion Tester. The surface was scored twice with a cutter wheel at a 90° angle to each other, and after the debris was brushed off, an adhesive tape was applied to the surface and peeled off at 180° from the surface. The performance was evaluated by comparison with standard documents. To evaluate the stability over time, the surfaces were stored at room temperature in Petri dishes and the contact angle and sliding angle measurements were carried out after 3, 4 and 5 months.

[0114] Whole Blood Drop Experiments. Small squares (approximately 5 mm x 5 mm) were cut from larger samples, placed in a Petri dish, and moistened using a Kimwipe moistened with DI water. A 5 μL drop of citrated whole blood was placed on the surface of each sample. The drop was gently blotted from the surface with a Kimwipe® at time intervals of 1 minute, 5 minutes, 10 minutes, and 15 minutes. Care was taken not to spread the liquid over the entire surface. Optical images of the surface were taken using constant illumination and distance from the sample. The integrated density of the intensity in these images was quantified using ImageJ software. Images were first cropped to ensure equal areas of interest. The images were background subtracted, then converted to 8-bit, and finally thresholded from 0 to 227. The integrated density of these images was then calculated by the software. Standard deviations are reported along with the mean of these values, calculated from a minimum of three replicates for each condition. A two-way ANOVA was performed to determine significance.

[0115] Whole Blood Staining Assay. Samples were cut into 1 cm x 1 cm squares and fixed to the bottom of a 24-well plate using double-sided tape. 500 μL of citrated whole blood was pipetted into each well and incubated for 20 minutes. After incubation, the surfaces were carefully removed from the wells, and the tape was removed to ensure that the untreated surface of the samples was completely free of blood. Samples were optically imaged and then placed into a new well plate with wells containing 700 μL of DI water. The wells were shaken at 100 RPM for 30 minutes using a shaker (VWR Incubating Mini Shaker, Troemner, LLC, Thorofare, NJ) to detach any blood that had been attached to the surface. The surfaces were then removed and 200 μL of the solution was pipetted into a new 96-well plate. Absorbance values ​​were read at 450 nm using a plate reader (Synergy Neo2, BioTek, Winooski, Vermont). Relative absorbance values ​​were calculated relative to the control sample, plain PO. Values ​​were reported as means with standard deviations obtained using a minimum of three replicates. Significance was determined using one-way ANOVA.

[0116] Bacterial attachment experiments. Surfaces were cut to size (approximately 15 mm in diameter) and washed with 70% ethanol before use. 250 mL of LB broth was mixed with 125 μL of kanamycin to make 50 μg / mL LB-Kan medium. A single bacterial colony was picked using a pipette tip and inoculated into the liquid medium, and the culture was incubated overnight at 37°C with shaking at 220 RPM. The overnight culture was divided into four replicate samples of 50 mL and centrifuged at 4×g for 10 minutes. The supernatant was then discarded and the pellet was resuspended in 1 mL of fresh LB-Kan medium to make a concentrated cell suspension for use in the experiments. Agar plugs were made by adding 300 mL of water to 9 g of agar to make a 3% agar mixture, which was autoclaved and poured into polystyrene petri dishes to solidify. The agar plates were stored at 4°C until use. Prior to starting the experimental procedure, agar plugs were cut to size to fit the test surfaces (approximately 15 mm in diameter). Bacteria were introduced to the plugs by adding 20 μL of cell suspension, which was then gently spread across the agar with a pipette tip and incubated for 5 minutes. Test surfaces were stamped with these plugs and placed between two glass plates. Surfaces were imaged using an Amersham Typhoon imaging system (GE). An unstamped surface was used as a control for background fluorescence. Images were analyzed using ImageJ software and fluorescence intensity was used to measure bacterial transfer to the surface. Standard error of the mean was calculated for these samples with five replicates for each condition. Significance calculations were performed using one-way ANOVA.

[0117] To directly quantify the number of bacteria transferred to the surface, the above protocol was modified slightly. Overnight grown bacterial cultures were cultured at approximately 5.7×10 7CFU / mL and used in place of concentrated cell suspension. The surfaces were stamped as described above and then mixed into 5 mL of LB-Kan medium. Bacterial transfer to the surfaces was measured by plating media from each stamped sample at various dilutions. In this case, 20 μL of media from the sample was mixed with 180 μL of PBS in a 96-well plate, with two replicate wells per sample. Dilutions up to 10-5 were made for each sample. 100 μL of sample was plated in triplicate using a cell spreader and incubated overnight (37°C). Plates were imaged using a ChemiDoc MP (BioRad) imaging system with Blot / UV / Stain-Free Sample Tray and Fluorescein settings. Images were analyzed using the Cell Counter plugin of ImageJ software. Standard error of the mean was calculated for the samples and significance was determined using one-way ANOVA.

[0118] Results and Discussion

[0119] Fabrication and characterization of polysiloxane hierarchical surfaces. The hierarchical n-PTCS surfaces were fabricated using a three-step method. First, planar PO substrates (cut to the desired size and shape) were activated by oxygen plasma treatment for 3 minutes. Next, a customized humidity chamber was used to grow n-PTCS nanostructures on the PO surface (using chemical vapor deposition for 6-24 hours). The substrates were first placed in the customized humidity chamber for 2 hours to stabilize the humidity at about 55% relative humidity (RH), followed by the addition of n-PTCS through a rubber stopper. Finally, the coated surface was subjected to a heat treatment at 145°C for 10 minutes to achieve wrinkle processing (Figure 1). As a substrate, biaxially oriented polyolefin, a widely available heat-shrinkable polymer film, was chosen to ensure scalability. Figure 2 shows the optimization of the 3-minute activation time to promote the condensation reaction. The growth time of n-PTCS was varied to optimize the structure of the hierarchical coating for maximum anti-adhesion properties (Figure 3).

[0120] Each type of surface was characterized by measuring the contact angle and sliding angle (Figure 3a) and visualized using a scanning electron microscope (SEM) (Figures 1b, 1c). The n-PTCS treated surfaces exhibited water contact angles >150° in both planar and hierarchical conditions, while water sliding angles varied widely for the planar surfaces but were consistently measured to be <15° for the shrunken surfaces. Based on these results, the hierarchical surface after 6 hours of incubation was selected as the best performing surface (contact angle: 153° and sliding angle: <1°) with the shortest growth period. Over the course of these measurements, the planar n-PTCS surface performed similarly to the hierarchical n-PTCS, but surface durability was greatly improved by the structural hierarchy. Touching the planar n-PTCS surface using light pressure often resulted in significant residue transfer from the surface. In addition, slight differences in coating thickness resulted in water droplets remaining on the planar n-PTCS surface during sliding angle measurements. None of these shortcomings were observed with the hierarchical n-PTCS. For hierarchical n-PTCS surfaces, a 5 μL water droplet was observed to bounce or slide across the surface, demonstrating superhydrophobicity (Figure 3b). Using slow motion recording of this phenomenon, the droplet was seen to bounce twice on the surface, with the first bounce reaching a height of approximately 0.5 cm. n-PTCS nanostructures were visible on the surface using a microscope before heat treatment and became integrated with wrinkles after the heat shrink process (Figures 1b, 1c). On planar surfaces, variations in the density of nanostructures were observed, but the shrink sample shows wrinkles across the surface at all time points (Figure 4). The n-PTCS nanostructures include both filamentous and rod-like structures that in some cases resemble volcanoes. 13n-PTCS nanostructures on PO are observed with diameters ranging from hundreds of nanometers to, in rare cases, over 1 μm. This variability is seen to some extent across individual surfaces and even across different growth times. The structures grown for 24 hours appear more filamentary with diameters of about 200 nm, while growing the structures for 6 hours results in more rod-like structures with diameters up to 1 μm (Figure 4). The bidirectional microscale wrinkles created by shrinkage also showed some variability across growth times, but all wrinkles were on the micrometer scale, including those created by 6 hours of growth (Figure 4).

[0121] Environmental and physical tests were also performed to test the stability of these surfaces. The hierarchical n-PTCS surfaces exposed to -20°C or 37°C environments for 24 hours showed no change in the measured contact and sliding angles (Figure 3c). They were also incubated in 100% ethanol for 1.5 hours. Again, these surfaces maintained stable superhydrophobicity with no significant change in contact or sliding angles (Figure 3d). The surfaces were also sonicated in 100% ethanol for increasing durations up to 15 minutes without any significant loss in superhydrophobic properties (Figure 3e). The ASTM International Standard Scratch Test was performed on the hierarchical n-PTCS surfaces, which classifies adhesion strength from 0 to 5B, with 5B indicating ideal adhesion. A classification of 4B was measured for the hierarchical n-PTCS, indicating that acceptable adhesion of the n-PTCS coating was achieved. Finally, long-term stability tests were performed on the hierarchical n-PTCS, and no degradation in contact angle and sliding angle was observed after 3, 4, and 5 months (Figure 3f). All these results support the use of these hierarchical n-PTCS surfaces for high-touch and variable environment applications.

[0122] Reduced Blood Adhesion for Biofouling Prevention. To evaluate the performance of the hierarchical n-PTCS surfaces in the presence of complex biological fluids, a preliminary characterization was performed using citrated whole blood to evaluate whether blood would adhere to the surface. In this experiment, a lubricant-treated hierarchical n-PTCS surface was also included as a control to compare the performance of the lubricant-free approach with that of liquid-infused surfaces known to have excellent anti-adhesion and anti-biofouling properties. Previous studies have demonstrated the effectiveness of silicone oil as a lubricant for nanofilament coatings, and to prepare a suitable comparison of the hierarchical surfaces, 10 cSt, 20 cSt, 50 cSt, 100 cSt, 350 cSt, and 1000 cSt silicone oils were investigated as lubricants for these surfaces. 100 cSt silicone oil was selected as the ideal viscosity based on the sliding angles in both planar and contracted samples, and when added to the hierarchical n-PTCS, it exhibited a water sliding angle of 5° and a water contact angle of 104° (Figure 5).

[0123] The contact angle of citrated whole blood on the hierarchical n-PTCS surface (140°) was significantly higher than that of the planar or shrink PO surfaces (Figure 6a). This significantly exceeds the blood contact angle measured on the lubricant-treated surfaces, while being comparable to that of the planar n-PTCS surface. A drop staining test was also performed by incubating the surfaces in a humidity chamber for 15 minutes. The hierarchical n-PTCS surfaces remained visibly clean after the staining test, especially compared to the planar and shrink PO controls (Figure 6b). To quantify these results, the integrated concentration of intensity in the images of each surface was measured. The trends in the intensity measurements were consistent with the visual assessment, indicating that the hierarchical n-PTCS surfaces significantly outperformed the control conditions at all time points (Figure 6c). The planar n-PTCS surface retained visible staining even after 5 minutes of incubation with blood, highlighting the advantage of structural hierarchy in anti-biofouling properties. The performance of the lubricant-free hierarchical n-PTCS surfaces was comparable to both planar and hierarchical lubricated surfaces, demonstrating that this hierarchical approach successfully eliminated the need for lubricants by performing comparable to these surfaces.

[0124] Further staining tests were also performed. In this test, the surface was incubated in citrated whole blood for 20 minutes, then gently removed and the untreated side of the sample wiped clean. The surface was then placed in a well filled with DI water and shaken for 30 minutes to remove any blood that had adhered to the surface. Measurements of the relative absorbance of these wells again show the resistance of the hierarchical surface to staining by a significant reduction between the flat or contracted PO and the hierarchical n-PTCS surfaces (Figure 6d). As with the droplet experiments, the performance of the hierarchical n-PTCS was comparable to the lubricant-treated surfaces, with no significant difference between the flat or hierarchical lubricant-treated n-PTCS. This successful reduction in staining of the surface indicates a high performance beyond visual cleanliness. Since biofilms are known to be promoted by fibrinogen deposited by surface contamination with blood, the reduction in blood adhesion minimizes the possibility of biofilm formation by bacterial species. This feature is particularly important for surfaces located in healthcare facilities that are regularly contaminated with blood and at the same time pose a risk of pathogen exposure.

[0125] Prevention of pathogen transfer to high-touch surfaces. To evaluate the pathogen adhesion prevention of these surfaces, an experiment was designed to mimic pathogen transfer to high-touch surfaces. The surfaces were examined for their ability to prevent bacterial adhesion using E. coli K-12, a bacterium transfected with green fluorescent protein. E. coli is a robust and widely available Gram-negative bacterium, and laboratory-maintained strains such as K-12 have been documented to persist on surfaces due to adherent mutations. Bacterial adhesion was quantified by first stamping the surfaces with agar plugs contaminated with E. coli, followed by measuring the fluorescence intensity on the surfaces (Figure 7a). The n-PTCS hierarchical surfaces showed a 1.6 log (97.5%) reduction in bacterial load compared to planar PO, demonstrating the ability of these surfaces to resist bacterial transfer (Figure 7b). To compare the performance of the lubricant-free surfaces with their corresponding lubricant-treated surfaces, the same series of samples used in the blood adhesion test were prepared and evaluated. Similar to the performance in complex biological fluids, no significant difference was noted between the lubricant-treated conditions and the hierarchical n-PTCS. Further experiments were performed to examine the amount of viable growing bacteria transferred to the surface by the contaminated stamp. In this case, as shown in FIG. 7c, the hierarchical n-PTCS surface exhibited a 1.2 log reduction (93%) compared to the control group. A reduction of 87% was observed between the planar PO and the hierarchical n-PTCS, while no significant difference was observed between the lubricant-treated planar n-PTCS or the lubricant-treated hierarchical n-PTCS and our ideal hierarchical n-PTCS. Taken together, these results indicate a significant resistance to surface contamination by using the developed lubricant-free and fluorine-free hierarchical surfaces. Not only this, but the results also show no significant difference between the hierarchical n-PTCS surface and its lubricant-treated hierarchical analog. As seen in FIG. 7b, the hierarchical n-PTCS surface outperformed the lubricant-treated planar n-PTCS surface (planar n-PTCS + lubricant) in this contact assay.This performance is consistent with previous hierarchical surfaces fabricated with heat-shrinkable surfaces, which showed a 20-fold reduction in fluorescent signal using the same experimental design, but were fabricated using a fluorosilane coating. 1 In addition, these surfaces perform in agreement with previous studies using polysiloxane nanostructures that showed a significant reduction in bacterial adhesion to glass slides coated with n-PTCS and infiltrated with silicone oil lubricant. 11 .

[0126] Although the present disclosure has been described with reference to examples, it should be understood that the claims should not be limited by the embodiments described in the examples, but should be accorded the broadest interpretation consistent with the specification as a whole.

[0127] All publications, patents, and patent applications are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference in its entirety. In the event that a term in this disclosure is found to be differently defined in a document incorporated by reference herein, the definition provided herein shall be construed as the definition of said term. References (1)Imani, SM; Maclachlan, R.; Rachwalski, K.; Chan, Y.; Lee, B.; McInnes, M.; Grandfield, K.; 454-465. https: / / doi.org / 10.1021 / acsnano.9b06287. (2)Lee, E.; Lee, K. H. Facile Fabrication of Superhydrophobic Surfaces with Hierarchical Structures. Sci. Rep. 2018, 8 (1), 4101. https: / / doi.org / 10.1038 / s41598-018-22501-8. (3)Hassan, L. B.; Saadi, N. S.; Karabacak, T. Hierarchically Rough Superhydrophobic Copper Sheets Fabricated by a Sandblasting and Hot Water Treatment Process. Int. J. Adv. Manuf. Technol. 2017, 93 (1-4), 1107-1114. https: / / doi.org / 10.1007 / s00170-017-0584-7. (4)Imani, S. M.; Maclachlan, R.; Chan, Y.; Shakeri, A.; Soleymani, L.; Didar, T. F. Hierarchical Structures, with Submillimeter Patterns, Micrometer Wrinkles, and Nanoscale Decorations, Suppress Biofouling and Enable Rapid Droplet Digitization. Small 2020, 16 (50), 1-9. https: / / doi.org / 10.1002 / smll.202004886. (5)Jiang, R.; Hao, L.; Song, L.; Tian, L.; Fan, Y.; Zhao, J.; Liu, C.; Ming, W.; Ren, L. Lotus-Leaf-Inspired Hierarchical Structured Surface with Non-Fouling and Mechanical Bactericidal Performances. Chem. Eng. J. 2020, 398. https: / / doi.org / 10.1016 / j.cej.2020.125609. (6)Artus, G. R. J.; Jung, S.; Zimmermann, J.; Gautschi, H. P.; Marquardt, K.; Seeger, S. Silicone Nanofilaments and Their Application as Superhydrophobic Coatings. Adv. Mater. 2006, 18 (20), 2758-2762. https: / / doi.org / 10.1002 / adma.200502030. (7)Jin, M.; Li, S.; Wang, J.; Liao, M.; Zhao, Y. Controllable Fabrication of Organosilane Nano-Architectured Surfaces with Tunable Wettability. Appl. Surf. Sci. 2012, 258 (19), 7552-7555. https: / / doi.org / 10.1016 / j.apsusc.2012.04.084. (8)Stojanovic, A.; Olveira, S.; Fischer, M.; Seeger, S. Polysiloxane Nanotubes. Chem. Mater. 2013, 25 (14), 2787-2792. https: / / doi.org / 10.1021 / cm400851k. (9)Zimmermann, J.; Artus, G. R. J.; Seeger, S. Superhydrophobic Silicone Nanofilament Coatings. J. Adhes. Sci. Technol. 2008, 22 (3-4), 251-263. https: / / doi.org / 10.1163 / 156856108X305165. (10)Kasapgil, E.; Anac, I.; Erbil, H. Y. Transparent, Fluorine-Free, Heat-Resistant, Water Repellent Coating by Infusing Slippery Silicone Oil on Polysiloxane Nanofilament Layers Prepared by Gas Phase Reaction of n-Propyltrichlorosilane and Methyltrichlorosilane. Colloids Surfaces A Physicochem. Eng. Asp. 2019, 560 (September 2018), 223-232. https: / / doi.org / 10.1016 / j.colsurfa.2018.09.064. (11)Kasapgil, E.; Badv, M.; Cantu, C. A.; Rahmani, S.; Yildirim Erbil, H.; Sakir, I. A.; Weitz, J. I.; Hosseini-Doust, Z.; Didar, T. F. Polysiloxane Nanofilaments Infused with Silicone Oil Prevent Bacterial Adhesion and Suppress Thrombosis on Intranasal Splints. ACS Biomater. Sci. Eng. 2021, 7 (2), 541-552. https: / / doi.org / 10.1021 / acsbiomaterials.0c01487. (12)Meier, M.; Dubois, V.; Seeger, S. Reduced Bacterial Colonisation on Surfaces Coated with Silicone Nanostructures. Appl. Surf. Sci. 2018, 459 (July), 505-511. https: / / doi.org / 10.1016 / j.apsusc.2018.08.003. (13)Artus, G. R. J.; Olveira, S.; Patra, D.; Seeger, S. Directed In Situ Shaping of Complex Nano- and Microstructures during Chemical Synthesis. Macromol. - Rapid Commun. 2017, 38 (4), 1-9. https: / / doi.org / 10.1002 / marc.201600558. (14) Li, B.; Cao, Y. P.; Feng, X. Q.; Gao, H. Mechanics of Morphological Instabilities and Surface Wrinkling in Soft Materials: A Review. Soft Matter 2012, 8 (21), 5728-5745. https: / / doi.org / 10.1039 / c2sm00011c.

Claims

1. A material comprising a shrinkable polymer substrate and at least one polysiloxane layer on a surface layer of the substrate, the material comprising microscale wrinkles and nanoscale features that form a hierarchical structure on a surface of the material, and the material exhibits superhydrophobicity.

2. the shrinkable polymer substrate comprises at least one selected from the group consisting of polystyrene, polyolefins, polyethylene, polypropylene, and other shrinkable polymers, or combinations and copolymers thereof; Preferably wherein said shrinkable polymer substrate is a polyolefin, and optionally said shrinkable polymer substrate is biaxially oriented. The material of claim 1.

3. The material of claim 1 , wherein the nanoscale features comprise filament-shaped and / or rod-shaped structures.

4. the at least one polysiloxane layer forms the nanoscale features; wherein optionally, said at least one polysiloxane layer is formed using a silane. The material of claim 1.

5. 10. The material of claim 1, wherein the at least one polysiloxane layer is formed using one or more compounds of formula II: 【Chemical 1】 [In the formula, R １ , R ２ , and R ３ are each independently a hydrolyzable group, and R ４ is C １～６ It is alkyl.

6. 10. The material of claim 1, wherein the at least one polysiloxane layer is formed using n-propyltrichlorosilane or the at least one polysiloxane layer is not formed using a fluorosilane.

7. The material has a static water contact angle of 150° to 165°, wherein optionally, the material has a water slide angle of less than 1°. The material of claim 1.

8. have antibacterial or antifouling properties, or exhibiting anti-adhesion properties to biological fluids, preferably blood, or exhibiting anti-fouling properties against liquids containing biological species, or exhibit anti-adhesion properties against bacteria and biofilm formation; The material of claim 1.

9. A device or article comprising the material of any one of claims 1 to 8, wherein the material is on a surface of the device or article.

10. 1. A method for producing a material having a surface with a hierarchical structure, the method comprising: a) activating the shrinkable polymer substrate by oxidation; b) depositing at least one polysiloxane layer onto said shrinkable polymer substrate at a substantially constant relative humidity; and c) treating said substrate under conditions to form microscale wrinkles and nanoscale features to obtain a material; wherein the material exhibits superhydrophobicity.

11. activating the substrate comprises introducing hydroxyl groups into or on the substrate; wherein optionally, activating the substrate comprises plasma treatment for a time period of from 30 seconds to 10 minutes, or from 2 minutes to 7 minutes, or from 3 minutes to 5 minutes. The method of claim 10.

12. the shrinkable polymer substrate provided in step a) is biaxially stretched, and optionally the method further comprises biaxially stretching the substrate prior to said activation; wherein optionally, said shrinkable polymer substrate is a polyolefin. The method of claim 10.

13. 11. The method of claim 10, wherein the relative humidity is maintained at 45% to 65%, or 50% to 60%, or 55% for 4 hours to 30 hours, or 5 hours to 24 hours, or 6 hours.

14. The method of claim 10, wherein the at least one polysiloxane layer is formed using n-propyltrichlorosilane.

15. The method of any one of claims 10 to 14, wherein the micro-scale wrinkles are formed by heat shrinking the material.

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