Cotton Fabric Surface Polymerization Modification And Its Finishing By Anisotropic Silver Nanoparticles

Cotton fabric functional modification is an important method to give the fabric special properties and increase its added value. Among a lot of modification methods, the surface polymerization modification attracted special attention because it can impart the fabric durable functional properties.In this study, the functional monomers were firstly grafted onto the surface of the cotton fabric by the activators regenerated by electron transfer atom transfer radical polymerization(AGRET-ATRP)method, then the cotton fabric was treated with anisotropic silver nanoparticles. This finishing approach gives cotton fabric bright colors, good UV resistant property as well as excellent antibacterial property.First of all, the 2-bromo isobutyryl bromide were introduced onto surface of the cotton fabric to produce the macroinitiator, then the macroinitiator initiated ARGET-ATRP reaction in a water /ethanol medium by using the Cu Br2 / pentamethyl diethylenetriamine(PMDETA) and vitamin C(Vc)as the catalyst system and the functional monomer 2-(Dimethylamino)ethyl methacrylate(DMAEMA)was grafted onto the cotton surface, and quaternized modified cotton fabric was prepared by further quaternization. The influence of various factors on the grafting ratio was explored, and the results showed that grafting ratio was affected by the concentration of CuBr2 and DMAEMA, the ratio of CuBr2/ PMDETA and CuBr2/Vc, the reaction temperature(T) and reaction time(t). What’s more, the grafting ratio of the cotton fabric can be controlled easily by changing the polymerization conditions.Fourier transform infrared spectroscopy(FTIR) proved that the monomers were successful polymerized onto the fabric surface, scanning electron microscopy(SEM) showed that the polymer wrapped in cotton fiber surface and formed a thin film. The antibacterial properties of quaternizedmodified cotton fabric was tested by colony counting method, the results showed that quaternized modified cotton fabric have excellent and durable antibacterial effect against Staphylococcus aureus.Secondly, anisotropic silver nanoparticles that have different colors were synthesized by a chemical reduction method. This study explored and discussed the effects of polyvinylpyrrolidone(PVP), the sodium citrate(TSC), the hydrogen peroxide(H2O2) and the sodium borohydride(NaBH4) in the reduction process and analyzes their roles and influences on the color,particle size and electric potential of anisotropic silver nanoparticles. The results showed that PVP,TSC, H2O2, NaBH4 play the different roles during the production of the anisotropic silver nanoparticles. Ideal anisotropic silver nanoparticles can be prepared by changing the dosage of reagents. UV visible light spectrum(UV-vis) and transmission electron microscope(TEM) showed that the anisotropic silver nanoparticles have different colors and different shapes.Finally, the quaternized modified cotton fabrics were dyed with the anisotropic silver nanoparticles, the anisotropic silver nanoparticals could be absorbed on the surface of quaternized modified cotton fabric by electrostatic attraction. Different color depth could be got by adjusting the silver concentration and the graft ratio of the fabrics. This finishing method not only gives cotton fabric bright color, but also gives it excellent UV resist performance. In addition, the antibacterial properties of the fabric are further improved. This research can provide a new idea for the functionalization of cellulose.