The Preparation And Application Study Of Chitosan And Its Derivatives Composites

Chitosan(CS),also known as deacetyl chitin,is obtained by deacetylation of chitin which is widely existing in nature.Since its good biocompatibility,safety and degradability,it has been widely used in medicine,food,chemical industry and many other fields.In this paper,nano-silver solution was prepared and applied to the antibacterial finishing of cotton fabric.CS was modified to improve water solubility.Then the dyeing properties of tea polyphenols on silk fabrics coated with modified CS were investigated by using modified CS to improve the theoretical basis for the functional modification of CS.And this improves the theoretical basis for the functional modification of CS.In this paper,the chitosan-Ag-Nano-particles(CS-AgNPs)was prepared by liquid-phase chemical reduction with CS as protective agent and glucose as reducing agent.The effects of different experimental conditions on the preparation of silver nanoparticles were investigated.The composite was characterized by scanning electron microscope(SEM),particle size measurement,Ultraviolet visible spectrum(UV-Vis),infrared spectroscopy(FT-IR)and X-ray diffraction(XRD).The stability and antibacterial properties of CS-AgNPs solution were studied.The results showed that the size distribution of CS-AgNPs was uniform and the stability was good.The minimum inhibitory concentrations for Escherichia coli and Staphylococcus aureus were 12mg/L and 10 mg/L,respectively.The antibacterial finishing process of cotton fabric with CS-AgNPs solution was discussed in this paper.The structure and properties of the finished cotton fabric were also studied.The optimum finishing process was showed as follow:the cotton was treated with O.Olmol/L silver nitrate with the finishing temperature 90? and the finishing time 4h.SEM diagram showed that the silver nanoparticles were successfully loaded on the finished cotton fabric and the coated cotton had excellent antibacterial and washing resistance.The bacteriostasis rates of Escherichia coli and Staphylococcus aureus were both above 99%.The bacteriostatic rate could be maintained about 90%after 50 standard washing cycles.After finishing,the mechanical properties of cotton fabric were improved,and the water absorption and moisture permeability decreased.The technological conditions of CS modified by sodium periodate oxidation were discussed by comparison of spectral method and aldehyde titration method.On this basis,we prepared dialdehyde chitosan(DACS).The DACS was coated on the silk and the dyeing properties of finished silk fabric were studied.The results showed that,after modification,aldehyde groups appeared on CS which improving the water solubility and the dyeing performance of tea polyphenols was improved after DACS was finished on silk fabric.In order to study the adsorption process of tea polyphenols dyeingon silk fabric,an adsorption model was confirm after fitting the experimental results.