Effects of addition of silica nanospheres on mechanical properties of clay/sodium polyacrylate hydrogels

In this study, we investigated the effect of the addition of silica (SiO2) nanospheres on the mechanical properties of clay/PAAS hydrogels. Consequently, the addition of SiO2 nanospheres to the clay/PAAS hydrogels remarkably enhanced mechanical performance such as tensile strength and extensibility. Interestingly, quartz crystal microbalance (QCM) and Fourier transform infrared spectroscopy (FT-IR) measurements reveal that SiO2 nanospheres do not adhere to any other constituents despite the improvement of mechanical performance. Additionally, synchrotron small-angle X-ray scattering (SAXS) analysis reveals that clay platelets comparatively disperse in the clay/SiO2/PAAS hydrogels. We conclude from these results that the mechanical performance enhanced by the addition of SiO2 nanospheres may come from the increase in the number of PAAS molecules adsorbed on clay particles arising from the electrostatic repulsion between SiO2 and PAAS.

Automated summary

The addition of SiO2 nanospheres to clay/PAAS hydrogels significantly enhances mechanical performance such as tensile strength and extensibility, without adhering to other constituents. SAXS analysis reveals that clay platelets disperse comparatively in the hydrogels.