Fabrication of super water repellent silver flake/copolymer blend films and their potential as smart fabrics

Abstract

A facile technique is demonstrated for the fabrication of super water repellent co‐polymer blend‐silver composite films from fatty acid surface functionalized fine silver flakes. Initially, high concentrations of surface functionalized silver flakes were dispersed in poly(vinyl chloride‐co‐vinyl acetate‐co‐vinyl alcohol) copolymer in solution to form electrically conducting adhesives/paints (ECAs) with a bulk resistivity of ∼3 × 10−5 Ω cm. The solvent‐borne ECAs were then blended with a water‐dispersed perfluoromethacrylate copolymer (Zonyl 8740) using a simple solvent‐inversion process to obtain super water‐repellent colloidal copolymer blend‐silver emulsions. The colloidal emulsions could be spray‐deposited on a number of fibrous substrates including fabrics and paper. A particular example is demonstrated herein by spray‐depositing these emulsions onto molten paraffin wax‐based laminates (60°C), which were partially impregnated into fabrics to fabricate highly water repellent, flexible, and thermoresponsive fabrics. A paraffin wax/polyolefin blend base film was used for the purpose. The surface topology of the superhydrophobic copolymer/silver composite films displayed fractal‐like hierarchical structures ideal for self‐cleaning hydrophobicity. On relatively low‐absorbent permeable porous surfaces such as cellulosic films (paper) impregnated with wax/polyolefin films, self‐cleaning ability of the coatings was maintained even for temperatures at which paraffin wax component of the laminated film was molten indicated by low‐water roll‐off angles. Hence, the composites have excellent compatibility with organic phase change materials such as paraffin wax and wax/polyolefin blends, and they can be used to fabricate nonwetting, thermoregulated, and electroactive fabrics. Antimicrobial properties of silver offer additional advantages for potential biomedical applications. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

Chemically Resistant, Electric Conductive, and Superhydrophobic Coatings

“…[48] In order to test the long-term stability of coatings to acidic or basic fluids, the prepared coatings were immersed into the aqueous solutions of acidic (pH 2) and basic (pH 14) nature. [48] In order to test the long-term stability of coatings to acidic or basic fluids, the prepared coatings were immersed into the aqueous solutions of acidic (pH 2) and basic (pH 14) nature.…”

“…[11,12] In general, practicability, scalability, and good chemical and mechanical stability of superhydrophobic coatings are required for their practical use, but multifunctionality of superhydrophobic coatings has been a new focus of academic and industrial interest. Thanks to such interest of making superhydrophobic surfaces smarter by adding some functionalities, recent studies show fabrication of superhydrophobic surfaces with added functionalities such as optical transparency, [13] antimicrobial activity, [14] magnetism, [15,16] and electrical conductivity, etc. [17] For example, superhydrophobic surfaces combined with electric conductivity are known as promising candidates for smart textiles, [18] nonwetting electromagnetic interference shielding, [19] and electrode materials.…”

Surfaces with Extreme Wettability Ranges for Biomedical Applications

“…Distinct classes of materials have been employed to produce superhydrophobic surfaces that mimic the structure of lotus leaves, such as natural polymers [32,33]; synthetic polymers [34][35][36]; synthetic organic, inorganic, or hybridized organic-inorganic materials [37][38][39][40][41]; and metals [42][43][44].…”

Smart polymer nanocomposite water and oil repellent coatings for aluminum

“…Fabrication of multifunctional super-hydrophobic fi lms and coatings is gaining more and more academic and industrial interest due to a combination of liquid repellency with other properties such as electrical conductivity [1][2][3][4][5][6][7][8] , magnetic activity [9][10][11][12][13][14] , transparency [15][16][17][18][19] , antimicrobial properties [20][21][22][23][24][25] , strong substrate adhesion [26,27] , mechanical robustness [27][28][29][30][31][32] , icing prevention [33][34][35][36][37][38][39][40][41][42][43] and self-healing [44] . As such, multifunctional liquid repellent fi lms and coatings can be used in many applications including corrosion prevention, electromagnetic shielding, biomedical technologies, lab-on-a-chip, solid state and electrochemical batteries, membrane science, exterior/interior paint and coatings industry to name a...…”

“…The nanocomposites remain electrically conductive at all times even after conversion into super-hydrophobic state, maintaining an electrical conductivity of 25 S/m. The developed coatings can have applications in corrosion protection for metal surfaces, conductive electrode materials for electrochemical energy conversion devices and lab-on-a-chip systems.Fabrication of multifunctional super-hydrophobic fi lms and coatings is gaining more and more academic and industrial interest due to a combination of liquid repellency with other properties such as electrical conductivity [1][2][3][4][5][6][7][8] , magnetic activity [9-14] , transparency [15][16][17][18][19] , antimicrobial properties [20][21][22][23][24][25] , strong substrate adhesion [26,27] , mechanical robustness [27-32] , icing prevention [33-43] and self-healing [44] . As such, multifunctional liquid repellent fi lms and coatings can be used in many applications including corrosion prevention, electromagnetic shielding, biomedical technologies, lab-on-a-chip, solid state and electrochemical batteries, membrane science, exterior/interior paint and coatings industry to name a few.…”