Study On Preparation Of Antibacterial Natural Fiber Materials By Surface Modification

Cotton,as the most widely used natural fibers,has attracted much attention because of its breathable,soft,and degradable nature.With the development of surface science and composite technology,more and more cotton fibers have been investigated for functionalization so as to give versatile applications,including super hydrophobicity / superoleophobicity,UV protection,flame retardation,and electrical conductivity.In order to improve the biological properties of the cotton fiber,the cotton fiber may be surfacemodified or chemically modified by using a stable covalent bond between the cellulose.The development of new antibacterial cotton fabrics with excellent antibacterial activity,antibacterial durability,remarkable washing durability and improved stability of nanosilver on the fiber surface are the main research directions.In this paper,the surface of cotton fibers and various materials are modified by the insertion reaction of diarylcarbene,and combined with nano silver(Ag NPs)to impart antibacterial properties without changing the overall properties of the material.Due to the short synthetic route and mild reaction conditions,it provides a new idea for polymer modification and functionalization.Two types of nanosilver-cotton fabric composites were designed and prepared by using cotton fiber as the matrix material and loading nanosilver on the surface.One method is based on amino-substituted diazomethane,which introduces an amino group on the surface of cotton fibers by a heated carbene insertion reaction to obtain amino-modified cotton fibers.After amidation,a thioethermodified cotton fiber is prepared by loading a thioether group on the surface of the cotton fiber.The other is based on the methylthio-substituted diazomethane,and the methylthio group is directly introduced into the surface of the cotton fiber by a carbene insertion reaction to obtain a methylthio-modified cotton.Then,the modified cotton is coordinated with the nanosilver by solvent impregnation to obtain a corresponding nanosilver-cotton fabric composite material,which imparts excellent antibacterial properties to the cotton fiber.In summary,cotton fibers with amino groups and thioether groups were prepared,and the binding ability of three types of cotton fibers with hydroxyl,amino and thioether groups with nanosilver were compared.The antibacterial properties of three types of nanosilver-cotton fiber materials were also evaluated.Moreover,the obtained thioether carbene can not only modify cotton,but also can be used to modify materials such as cotton cloth,filter cloth,and non-woven fabric.This expands the application range of carbene surface modification technology and provides theoretical guidance for the preparation of new antibacterial cotton.