Preparation and performance of nanocomposite hydrogels based on different clay-Qingsong Zhang

To look for economic substitute of Laponite, two kinds of clay minerals purchased in China were chosen to prepare nanocomposite hydrogels. Structure, morphology, temperature-sensitivity and swelling behavior were investigated by XRD, SEM, DSC and gravimetric method. In comparison with hydrogel cross-linked by
Laponite XLG, the hydrogel with hectorite (Lvjie trademark) or montmorillonite (G-105) as cross-linker exhibited higher swelling ratios as well as faster response rate. In the case of temperature-sensitivity, the volume phase transition temperature (VPTT) of the hydrogels cross-linked by hectorite (Lvjie trademark) and montmorillonite (G-105) was 31–33 °C, slightly different from hydrogels with Laponite XLG. The hydrogel with montmorillonite (G-105) was brown and fragile. The hectorite (Lvjie trademark) appeared as optimal substitute of Laponite in hydrogels because the prepared hydrogel exhibited high swelling ratio, rapid response rate, excellent thermal responsibility, good dispersion in hydrogel matrix and high storage modulus.