▎ 摘　　要

Graphene-doped ZnO nanoplates (G-ZNPs) were incorporated as a reinforcing material into polyvinyl alcohol (PVA) to prepare nanocomposite PVA/G-ZNP hydrogels through a cyclic freezing-thawing method. The mechanical properties, water content, gel fraction, swelling ratio, dye absorption, water contact angle, thermal stability, and antibacterial properties were explored. In addition, the nanocomposites were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The tensile strengths of the hydrogels increased from 1.9 to 2.2MPa when the G-ZNP content ranged from 0 to 0.3 phr. The mechanical properties of the xerogels (obtained from freeze drying the hydrogels for 24 and 48 h) were the same as those of the hydrogels. Increasing the G-ZNP content improved the swelling ratio and dye absorption capacity because of the higher porosity, and the maximum ratio and capacity were reached when the G-ZNP content was 0.4 phr. The contact angle increased with addition of G-ZNP because of the more compact structures of the nanocomposite PVA/G-ZNP hydrogels and the lower surface roughnesses. The results of FTIR analyses showed that PVA underwent coordination reactions and hydrogen bonding with the G-ZNPs, and these synergistically enhanced the tensile strength of the PVA. The results of XRD analyses showed that with an increase in the G-ZNP content, the crystallinity of the xerogels first decreased and then increased. When the G-ZNP content was 0.3 phr, the crystallinity was the lowest, implying that at a content greater than 0.3 phr, the G-ZNP nanomaterials would not be well dispersed. Moreover, EDS analyses showed that the G-ZNPs were relatively uniformly dispersed in PVA hydrogels at a content of 0.3 phr. SEM analyses showed that incorporation of a small amount of G-ZNPs changed the microscopic morphology of the gels, and the three-dimensional network structure of the nanocomposite gels became dense. In addition, G-ZNPs enhanced the antibacterial and dye absorption abilities of the hydrogels.