Polyacrylamide-based inorganic hybrid flocculants with self-degradable property

Polyacrylamide (PAM)-based inorganic hybrid materials are of great potential as flocculants in soil-liquid separation. Herein, we reported the design of inorganic soil-TiO2-PAM hybrid materials using a unique process, which involved coating of titanium dioxide (TiO2) nanoparticles on the surface of inorganic soils and subsequent polymerization of acrylamide (AM) on these nanoparticles under visible light. Inorganic soils including kaolin, bentonite, montmorillonite and diatomaceous earth were used to control the volume and to reduce the cost, and the TiO2 nanoparticles accelerated PAM degradation. The nanoparticles initiated AM polymerization directly under visible light, thus providing a facile strategy for the synthesis of new organic-inorganic hybrid flocculants. The obtained hybrid materials were characterized using Fourier transform infrared spectroscopy and transmission electron microscopy. The degradation of PAM initiated by UV irradiation exceeded 24% in 2 h, depending on its initial concentration.