title: Highly water-absorbing silk yarn with interpenetrating network via in situ polymerization.
abstract: Silk was modified via in situ polymerization of two monomers acrylamide and sodium acrylate by swelling in an effective LiBr dissolution system. Swelling of natural silks in LiBr solutions of low concentration was clearly observed under optical microscope, and their conformational changes were revealed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Dissolution tests and FTIR spectra of these modified silks suggested the presence of interpenetrating network of polyacrylamide and poly(sodium acrylate) in the silk yarns. These modified silks exhibited superior water absorption to that of raw silk and greatly improved mechanical properties in both dry and wet states. These novel modified silks also showed low cytotoxicity towards skin keratinocytes, having potential applications in biomedical textiles. This modification method by in situ polymerization after swelling in LiBr provides a new route to highly enhance the properties and performance of silk for various applications.
authors.affiliation: Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Ka I
authors.initials: KI
authors.lastname: Lee
authors.affiliation: Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Xia
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Ka-Fu
authors.initials: KF
authors.lastname: Yung
authors.affiliation: Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. Electronic address: tcfeib@polyu.edu.hk.
authors.forename: Bin
authors.initials: B
authors.lastname: Fei
mesh_terms: D065966:Absorption, Physicochemical; D001965:Bromides / Q000494:pharmacology; D005349:Fibroins / Q000737:chemistry* / Q000633:toxicity; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects; D018020:Lithium Compounds / Q000494:pharmacology; D055595:Mechanical Phenomena; D055503:Protein Multimerization / Q000187:drug effects; D020836:Protein Structure, Quaternary; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D001965:Bromides; D018020:Lithium Compounds; D014867:Water; C040949:lithium bromide; D005349:Fibroins
keywords: In situ polymerization; Silk; Water absorption