Zhiming Jiang

N-halamine-bonded cotton fabric with antimicrobial and easy-care properties

N-halamine precursor 2,2,6,6-tetramethyl piperidinol (TMP), a hindered amine light stabilizer, was bonded onto cotton fabric by using 1,2,3,4-butanetetracarboxylic acid (BTCA) as a crosslinking agent. A variety of treating conditions including TMP concentration, curing temperature and time, and catalyst were studied. The treated fabrics were characterized using FTIR spectra and scanning electron microscope (SEM). The cotton fabric treated with TMP precursor could be rendered biocidal upon exposure to dilute household bleach. The chlorinated cotton swatches showed great efficacy and inactivated 100 % of Staphylococcus aureus with 7.1 log reduction with 5 min of contact and 83.25 % of E. coli O157:H7 at 10 min of contact. In addition, the wrinkle recovery angle of the treated cotton fabrics increased from 229 ° of untreated cotton fabrics to 253 °. This study provided a practical finishing process to produce cotton fabrics with easy care and antibacterial functionalities at the same time.

Antimicrobial modification of cotton by reactive triclosan derivative

Abstract4-(4-chloro-6-(5-chloro-2-(2,4-dichloro-phenoxy)phenoxy)-1,3,5-triazin-2-ylamino)-benzenesulfonic acid sodium (CPTB), an antimicrobial agent, was synthesized from cyanuric chloride, sulfanilic acid and triclosan. The synthesized compound was coated on cotton fabrics by covalent bonds through a reactive dyeing process. The cotton fabrics coated with CPTB were characterized by FTIR and SEM. The antimicrobial properties against S. aureus and E. coli O157:H7 and the breaking strength of the treated cotton fabrics were examined before and after chlorination. The unchlorinated coated fabrics containing triclosan inactivated 95.88 % of S. aureus and 79.65 % of E. coli O157:H7 within 30 min, while the chlorinated coated samples enhanced the efficacy significantly and inactivated all S. aureus and E. coli O157:H7 within 10 min. The novel coating process in this study only caused a small degree of breaking strength loss compared with traditional pad-dry-cure coating. Washing tests and UV light tests showed that CPTB attached to cotton fabrics was very stable toward repeated washing and UVA irradiation.

Development and characterisation of antibacterial suture functionalised with N-halamines

Braided and biodegradable polyglycolide suture was antibacterially functionalised with N-halamines via layer-by-layer assembly technique. Multilayers of chitosan (polycation) and poly-sodium-p-styrenesulfonate (polyanion) were successfully coated via electrostatic assembly, followed by top layer of chitosan on polyglycolide suture. Upon chlorination of coated suture with dilute sodium hypochlorite solution, the amino groups of chitosan were transformed into N-halamine structures. The transformation was assessed by iodometric/thiosulfate titration, Fourier transform infrared spectroscopy and differential scanning calorimeter analysis. The surface morphology of coated suture was observed by scanning electron microscope and atomic force microscope. Chlorine loading, antibacterial efficacy and tensile strength of chlorinated sutures treated with two different molecular weights of chitosan were compared and evaluated. A general trend of linear increase in chlorine loadings of sutures with the increase in number of layers and solution concentration was found. The chlorinated suture with high molecular weight chitosan coating completely inactivated both Escherichia coli O157:H7 and Staphylococcus aureus bacteria within 15 min of contact time. The 3T3 mouse fibroblasts in vitro cell cytocompatibility studies demonstrated that antibacterial sutures have fairly good biocompatibility.

N-halamine modified polyester fabrics: Preparation and biocidal functions

A cyclic N-halamine precursor, 1-glycidyl-s-triazine-2,4,6-trione (GTT), was synthesized and grafted onto polyester fibers. The tricarbimide rings could be transferred to N-halamine structure upon exposure to dilute sodium hypochlorite solution. Structural and surface characterizations of the polyester (PET) fabrics treated with GTT were accomplished using FT-IR, SEM, and DSC. The antimicrobial efficacy test showed that the N-halamine modified PET could inactivate 6-log of Staphylococcus aureus (Gram-positive) and E. coli O157:H7 (Gram-negative) within 10 min of contact time. The antimicrobial fabrics exhibited good durability and stability to washing and storage.

N-halamines as antimicrobial textile finishes

N-halamines have shown great potential in antibacterial products, and the development of N-halamine antibacterial textiles has drawn much attention from academic, health care, and industry researchers. This chapter covers advances in antibacterial textiles using various kinds of N-halamine compounds, which were attached to textile fibers chemically or physically. N-halamines can be used alone or combined with other antibacterial agents, such as quaternary ammonium salts and titanium dioxide, to produce biocidal textiles. Some studies also focused on the manufacturing of antimicrobial fibers with N-halamines via electrospinning.

Water repellent treatment of cotton fabrics by electron beam irradiation

In this study, traditional dip-pad-cure (DPC) process and electron beam (EB) irradiation were used to graft cotton fabrics with fluorine containing chemical, 1H,1H,2H,2H-perfluorooctyl acrylate (PFA). The grafted cotton fabrics were characterized by FT-IR and SEM. The water repellent properties were measured by contact angle, hydrostatic pressure, and spry test. It was found that there was no significant difference between the grafted cotton fabrics with DPC and EB methods, and the treated fabrics showed good water-resistant properties. The grafted cotton fabrics also showed good washing stability. By measuring the bending rigidity and bending hysteresis, it was found that the cotton fabrics grafted with PFA became softer than untreated samples.