We investigated the effects of silica(SiO₂) and clay nanoparticles on the tensile properties of poly(vinyl alcohol) (PVA) hydrogels containing borax. Clay/PVA/borax hydrogels possessed comparatively high tensile strength even at low concentrations of clay, but the mechanical performance drastically became worse at high concentrations. On the contrary, the tensile strength of SiO₂/PVA/borax hydrogels increased with increasing SiO₂ concentrations under high elongation. In these hydrogels, multiple crosslinking such as physical interactions between clay and PVA, complexations between PVA (or SiO₂) and borate, microcrystals of PVA produced a tough polymer network. Besides, the synergistic effects of clay and SiO₂ nanoparticles on the mechanical performance of the PVA/borax hydrogels were confirmed, i.e., both extensibility and modulus were largely improved compared to clay/PVA/borax or SiO₂/PVA/borax hydrogels. Synchrotron small-angle X-ray scattering analysis revealed that the addition of both clay and SiO₂ nanoparticles suppressed inhomogeneities in the composite gel.

我们研究了二氧化硅 (SiO ₂ ) 和粘土纳米颗粒对含硼砂的聚乙烯醇 (PVA) 水凝胶拉伸性能的影响。粘土/PVA/硼砂水凝胶即使在低粘土浓度下也具有相对较高的拉伸强度，但在高浓度下机械性能急剧变差。相反，在高伸长率下，SiO ₂ /PVA/硼砂水凝胶的拉伸强度随着SiO ₂浓度的增加而增加。在这些水凝胶中，粘土和 PVA 之间的物理相互作用、PVA（或 SiO ₂）和硼酸盐之间的复合、PVA微晶等多重交联产生了坚韧的聚合物网络。此外，粘土和SiO ₂的协同作用纳米颗粒对 PVA/硼砂水凝胶的机械性能的影响得到证实，即与粘土/PVA/硼砂或 SiO ₂ /PVA/硼砂水凝胶相比，其延展性和模量都有很大提高。同步加速器小角 X 射线散射分析表明，粘土和 SiO ₂纳米颗粒的添加抑制了复合凝胶中的不均匀性。