Design And Synthesis Of Antibacterial Finishing Agents And Its Application On Fabrics

The porous structure of the textile easily absorbs sweat and sebum of the human body,providing a suitable growing environment for the microorganisms.Pathogenic microorganisms cause many problems,such as human diseases,food spoilage,and clothing plaque.With the improvement of living standards,people's additional functional requirements for textiles are getting higher and higher.Therefore,antimicrobial finished textiles that meet the requirements of comfort and health have become hot research topics.People have put forward stricter requirements for antimicrobial finishing agents and finishing processes.High-efficiency,broad-spectrum,durable antimicrobial,safe,no toxic and no skin-irritated antibacterial characteristic are the trend of future development of textiles.In this paper,three kinds of antimicrobial finishing agents were designed and synthesized,and their chemical structures are confirmed by FTIR and ~1H-NMR.A facile and ecofriendly finishing technique to fabricate durable antimicrobial cotton fabrics using antimicrobial finishing agents by a dipping–padding–drying process.By contrasting the antibacterial activity,mechanical properties,moisture permeability and other properties before and after finishing,studies indicate that antibacterial fabrics have high-efficiency antibacterial activity with well-preserved physical properties,no toxicity and no skin irritation.The research also modify the polyvinyl alcohol nanofibers with the two reactive antimicrobial finishing agents,and explored its antibacterial activity in the last chapter.Firstly,the reactive antibacterial finishing agents trichloro-triazine-based quaternary ammonium salts with different carbon chain lengths(CQAS-Cn,n=8,10,12,14,16,18)are designed and synthesized,and their chemical structures are confirmed by nuclear magnetic resonance(~1HNMR).This paper also research the minimum inhibitory concentration(MIC)of antibacterial finishing agents(CQAS-Cn)with different carbon chain lengths,and textile's antibacterial activities with different concentrations of antibacterial finishing liquid.Exploring the antibacterial rate of the modified cotton textiles by live bacterial counting method,the results show that the antibacterial finishing agent with a chain length of 16 carbons(CQAS-C16)has the lowest MIC(E.coli:4?g/mL,S.aureus:1?g/mL),but the cotton fabrics finished with the chain length of 14 carbons(CQAS-C14)have the best antibacterial activity.In order to explore the feasibility of CQAS-C14 as an antibacterial finishing agent on cotton textiles,CQAS-C14 is chemically bonded to the surface of cotton textile that was confirmed by FTIR and XPS.The surface and cross section of cotton textiles are observed by SEM,which shows that the finishing process does not cause damage to the fiber.According to the relevant national standards,the results show that modified cotton textiles remain the original properties of cotton textiles,such as air permeability,moisture permeability,breaking strength,breaking elongation,tear strength and bursting strength.After washing 50 times,the antibacterial rates against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)are86.8%and 99.9%,respectively.Animal skin irritation experiments and animal oral toxicity tests of CQAS-C14 indicate no irritation and no toxicity.The antibacterial mechanism of CQAS-C14 is explored by proteomic analysis,and shows that CQAS-C14 causes the lack of various enzymes in E.coli by affecting ribosomes and the synthesis of proteins,so that the growth of bacteria is inhibited and the bactericidal effect is achieved.In conclusion,CQAS-C14 is an efficient,stable and safe antibacterial finishing agent.Secondly,a pH-responsive antibacterial finishing agent(IGua-Boc)is designed and synthesized.FTIR and XPS are used to confirm that IGua-Boc is chemically bonded to the surface of cotton fabrics,and the Boc-group is taken off after acid treatment.The raw cotton fabrics and the cotton fabric finished with the IGua-Boc have no antibacterial activity,while the cotton with the IGua-Boc after acid-treating has strong antibacterial activity;even at low concentration of IGua-Boc finishing solution(1 wt%).The antibacterial rate against E.coli and S.aureus are over 99.9%after acid-treating(pH=1)for 2 h.Finally,the reactive isocyanate quaternary ammonium salts(IQAS)and zwitterions(ISB)are designed and synthesized,and apply them on PVA nanofiber substrates.The chemical structures of IQAS and ISB are confirmed by FTIR and HNMR.The relation between the concentration of IQAS antibacterial finishing agent and the antibacterial rate of PVA/IQAS is explored.It shows that the PVA prepared by the concentration of IQAS finishing solution which is more than 10 g/L could obtain antibacterial rate against E.coli and S.aureus were over 99.9%.We find that the surface of PVA/IQAS adhered to a large number of bacteria,and the surface of PVA/IQAS/ISB shows almost no bacteria,and the antifouling property of PVA/IQAS/ISB is obtained.Furthmore,the double-finished PVA/IQAS/ISB also retains the non-toxic.