Carboxymethyl cellulose gels immobilized Ag/AgCl-ZnO nanoparticles for improving sunlight-catalyzed antibacterial performance.

Antibacterial sodium carboxymethyl cellulose (CMC) gels were prepared via immobilizing ZnO and/or Ag/AgCl in situ to inhibit the aggregation of nano-photocatalyst. Epichlorohydrin was used as a crosslinking agent to prepare CMC gel, simultaneously introducing chlorine-containing branch chains as Cl reservoir to deposit AgCl. The composite gels presented pH responsive swelling properties, with the minimum swelling ratio at pH 8 and pH 4 for CMC gels containing Ag/AgCl and ZnO, respectively. Zn2+ release from the nanocomposite gels was much greater in acidic than in neutral. Photocatalytic degradation constants of methyl orange by the composite gels under sunlight were greater than UV irradiation. Ag/AgCl loaded gel showed a degradation rate of 71.3 % under sunlight for 1 h, with a rate constant approximately 10.2 times higher than ZnO loaded gel. Extract liquids with the gel content below 0.33 mg/mL were noncytotoxicity. The nanocomposite gels presented good bactericidal rate against E. coli and S. aureus under sunlight for 6 h, comparatively to those in dark for 24 h. Bacteriostatic activity of Ag/AgCl loaded gel under sunlight for 6 h was much greater than that in dark for 24 h. The biocompatible nanocomposite gels with sunlight-catalyzed antibacterial activity would broaden the application of CMC gels.

Silver-based nanocomposite for fabricating high performance value-added cotton.

Cotton is one of the most important cellulose fibers, but the absence of antimicrobial capacity along with the self-cleaning, UV protection and electric conductivity often frustrates its wider applications in many fields. Nanotechnology has provided new insights into the development of functional nanomaterials with unique chemical and physical properties. Silver has been effectively incorporated into the cotton fabrics as the antimicrobial agents due to the strong inhibitory and antimicrobial effects on a broad spectrum of bacteria, fungi and virus with low toxicity to human being. In this review, a variety of strategies have been summarized to load silver on cotton fabrics in situ or ex situ and to fabricate high performance value-added cotton fabrics with self-cleaning, UV protection, electric conductivity and antimicrobial capability depending on the synthesis of silver coating or silver-based nanocomposite coating.