Durable Antibacterial Cotton Fabrics Containing Stable Acyclic N-Halamine Groups

Abstract

Inexpensive and commercially available methylene-bis-acrylamide (MBA) was covalently bonded onto the cotton fabrics by an effective catalytic solid-state reaction in water. The as-prepared MBA grafted cotton fabric (cotton-MBA) was characterized by field emission scanning electron microscopy image and Fourier transform infrared spectroscopy spectra. After a facile chlorination in diluted NaOCl solution, the amide functional groups in cotton-MBA were converted to N-halamine ones and durable antibacterial cotton fabric containing stable noncyclic N-halamine groups (cotton–MBA–Cl) was achieved. Antimicrobial testing showed that the cotton–MBA–Cl could effectively inactivate 5.78 × 107 CFU/mL of S. aureus and 7.58 × 108 CFU/mL of E. coli O157:H7 completely within 1 min of contact time. Washing durability testing indicated that the oxidative chlorine percentage of the cotton–MBA–Cl decreased from 0.43% to 0.06% after 50 washing cycles and was recovered to 0.30% via a simple rechlorination. It means that the N-halamine antimicrobial groups and the covalent bonds between MBA and cotton are very resistant to washing. Storage stability testing showed that the oxidative chlorine percentage of the cotton–MBA–Cl decreased from 0.43% to 0.32% after 30 day’s storage under room temperature, indicating that N-halamine functional groups are stable. Furthermore, it was found that the grafting and chlorination processes did not have any obvious bad effect on the tensile strength of cotton fabrics due to the mild grafting and chlorination conditions.

Synthesis of Multi‐Functionalized N–Cl Hydantoin Polyurethane for Chemical Warfare Agent Decomposition with High N–Cl Stability

“…Moreover, the electron‐donating methyl groups on hydantoin can help to stabilize N‐Cl form . Several researches have also paid their attention on the stability of N‐Cl as described in Supporting Information 1 . Based on the previous literature, the N‐Cl groups seem to be quite stable and have long enough shelter time before usage.…”

“…[37,38] Several researches have also paid their attention on the stability of N-Cl as described in Supporting Information 1. [14][15][16][29][30][31][32][33][34][39][40][41][42][43][44][45] Based on the previous literature, the N-Cl groups seem to be quite stable and have long enough shelter time before usage. However, it has been worthwhile to check that the active N-Cl concentration was around 0.5-1 wt% in most of them, which might be good enough in biocidal applications.…”

Medical textiles

“…The agents used were inexpensive and readily available commercially, treatment was mild and did not cause damage to the cotton, it was highly effective against both gram þ ve and gram-ve bacteria and it was rechargeable. Antimicrobial testing showed that the treated cotton inactivated 5.78 Â 10 7 CFU/mL of S. aureus and 7.58 Â 10 8 CFU/mL of the serotype of E. Coli named E. coli O157:H7 completely within 1 minute of contact, and following 50 wash cycles, although the remaining oxidative chlorine fell from 0.43% to 0.06%, it was able to be recovered to 0.30% via a simple re-chlorination using dilute NaOCl [252]. Similarly good results have been achieved by UV-photo-initiated thiolene click chemistry to apply the halamine precursor [253,254].…”

“…It was also claimed that the applied nano-composite finish of nano-titanium dioxide/methylene blue exhibited light-activated antiviral properties as measured using the bacteriophage X174 specified in ASTM F1671/1671M-13 as a surrogate for Hepatitis B virus, Hepatitis C virus and HIV [8] and it is considered to be an excellent choice for the testing of barrier materials [273]. This work [8] is alone in making claims for antiviral action by a fabric alongside it providing an antiviral barrier and it is disappointing that the test regimes applied to the N-halamines, which should be expected to be able to demonstrate antiviral effectiveness, did not include the antiviral test regime [247,248,[250][251][252]. Antiviral finishing and testing are topics worthy of much more attention by textile research groups; in the absence of antiviral finishing treatments or antiviral fibres, reliance must otherwise be placed solely upon the barrier aspect, resulting in a continuing slide towards single-use barrier fabrics, masks and respirators for viral protection, the consequential financial and environmental costs and the well-known high risks of supply-chain failure under the stresses of epidemic events.…”

Performance on Antibacterial Finishes for Textile Applications

“…The N-X bond is reduced during killing microbes by N-halamine agents with an advantage of reversibility of antimicrobial function. Halogenating agent like dilute solution of bleaching solution can recover the biocidal activity as illustrated in Figure 1; [3,4]. This pronounced recharging of antimicrobial functionality separate them from other classes of biocidal agents.…”