Preparation And Properties Of Regenerated Cellulose Copper-based Antibacterial Fiber

As a renewable and biodegradable material,cellulose fibers are known as“breathable fibers”due to the soft and smooth characteristics,moisture absorption,favourable dyeing and others.Because cellulose fibers do not have antibacterial activity,the fiber textiles will inevitably suffer from microbial invasion,which not only affects its performance,but also damages human health.In order to effectively block the transmission of bacteria,fungi and other microorganisms,it is extremely urgent to develop novel cellulose fiber materials with antibacterial properties.In this work,we used the TEMPO/Na Cl O/Na Br system to selectively oxidize the hydroxyl group at C₆ position of cellulose fibers to carboxyl group,which laid a foundation for subsequent graft of copper-thiosemicarbazone complexes.Secondly,thiosemicarbazone ligands were prepared by condensation reaction of aldehydes containing different substituents.Then,the ligands were coordinated with copper chloride.Finally,the copper-thiosemicarbazone complexes were conjugated with oxidation-cellulose fibers.The structures and properties of the fibers were analyzed by scanning electron microscope,Fourier transform infrared spectrometer and X-ray energy spectrometer,and the antibacterial properties were also evaluated.After selective oxidation by TEMPO/Na Cl O/Na Cl,the hydroxyl group at C₆ position of cellulose fiber is selectively oxidized into carboxyl group,and the surface of the oxidative cellulose fiber appears with streaks and cracks.In addition,the crystal diffraction peaks decrease with the increase concentration of the oxidants,and the mechanical properties of fibers concurrently decrease.After conjugating copper-thiosemicarbazone complexes,stable amide bonds were formed by condensation reaction.The surface of grafted cellulose fibers has an adhesion film layer,which is relatively flat and smooth compared with the oxidative cellulose fibers.Besides,the mechanical properties and thermal stabilities are also slightly improved.These grafted cellulose fibers have no antibacterial effects on gram-negative bacteria(E.coli),but have prominent antibacterial properties against gram-positive bacteria(Staphylococcus aureus and Bacillus subtilis).Therefore,copper-thiosemicarbazone complexes grafted cellulose fibers are regenerated cellulose-based materials with excellent antibacterial activity,which not only improve the economic values of original cellulose fibers,but also expand the application of cellulose-based materials in the fields of household textiles and health care.