Graphene Oxide/polysaccharide Microcapsules And Their Application In Slow And Controlled Release Antibacterial Textiles

The advantages of layer-by-layer self-assembly technology are flexible design,simple process and mild conditions.In recent years,layer-by-layer self-assembly technology has been widely used in medicine,agriculture,food,textile and other fields,and the technology has gradually become mature.In the process of preparing microcapsules by this technology,the wall materials are alternately assembled on the microcapsule template particles through interaction force,and finally the template is removed.Natural polysaccharides are used as wall materials to make microcapsules more green and environmentally friendly.GO in the wall materials can improve microcapsules mechanical properties and near-infrared laser(NIR)responsiveness.In this paper,Ca(NO₃)₂·4H₂O and Na₂CO₃ were used as raw materials,Poly(styrene sulfonic acid)sodium salt(PSS)was used as regulator.The optimal process for template preparation was that the PSS molecular weight was 70 K,the concentration was 1.0 mg/m L,the mixing time of three solutions was 10 s,and the standing time was30 min.The microcapsule template was spherical aragonite,with good morphology,uniform size,size of 5?8?m,and good thermal stability.Sodium alginate,chitosan,hyaluronic acid and GO were used as wall materials to prepare natural polysaccharide microcapsules and GO hybrid microcapsules.we can see that the microcapsules have complete structure and obvious hollow structure,and the size is 5?8?m by depth-of-field microscope,SEM and TEM.EDS and FTIR show the distribution of microcapsule elements and all components have formed microcapsules.TG and DTG show that the two microcapsules have strong thermal stability.The adsorption and release behaviors of the two microcapsules were studied by using dye model(Rhodamine B).The results showed that when the dye concentration was 2.0 mg/m L and the microcapsule mass was 5 mg,the adsorption capacity of natural polysaccharide microcapsules reached307.37 mg/m L and GO hybrid microcapsules reached 207.72 mg/m L.Moreover,the adsorption of dyes by the two microcapsules accords with the pseudo-second-order adsorption kinetic model and Langmuir adsorption isotherm model.The natural polysaccharide microcapsules released Rhodamine B at pH=5.8,which was higher than pH=7.4,but showed no response to NIR,while GO hybrid microcapsules showed stimulus response to both pH and NIR.The antibacterial drug ciprofloxacin was embedded in microcapsules to characterize its release behavior,and then the embedded drug microcapsules were coated on the surface of cotton fabric to prepare antibacterial fabric.The antibacterial effect was tested by plate diffusion method.The two kinds of blank microcapsules had certain antibacterial effects on Escherichia coli and Staphylococcus aureus,and the antibacterial effect was obvious after embedding ciprofloxacin,and the antibacterial effect of ciprofloxacin-GO microcapsule cotton fabric was further improved under NIR irradiation.