Study on the grafting of chitosan–gelatin microcapsules onto cotton fabrics and its antibacterial effect

In this work, patchouli oil embedded chitosan–gelatin microcapsules were prepared by the complex coacervation method. Their surface and morphology were characterized by scanning electron microscopy (SEM), showing that the microcapsules were with a regular spherical shape in the range of 1 and 20 μm. In the thermal stability analysis, the microcapsules were stable below 190 °C, which indicated the fabrics finish can be conducted at 160 °C. The encapsulation efficiency (EE) and loading capacity (LC) of the microcapsules were calculated as 50.69% and 30.31%, respectively. Then, the microcapsules were grafted onto cotton fabrics using 2D resin (dimethyloldihydroxyethylene urea, DMDHEU) as the crosslinking reagent. SEM showed that the microcapsules were not only grafted on the surface of the fabrics, but also inserted in the spacing of the fibers. In addition, the formation of ether bonds between 2D resin and hydroxyl groups of cotton and/or hydroxyl groups of the microcapsules was identified by Fourier transform infrared spectroscopy (FTIR). Finally, the antibacterial rate of the fabrics for Staphylococcus aureus and Escherichia coli were about 65% even after being washed 25 times, suggesting its potential application in many fields such as antibacterial mask, bacteriostatic sheet and health-care clothes.