Tuning morphology and mechanical property of polyacrylamide/Laponite/titania dual nanocomposite hydrogels by titania

Abstract

The tough polyacrylamide/Laponite/titania (TiO2) dual nanocomposite (NC) hydrogel was fabricated byin situradical polymerization of acrylamide (AAm) in the dispersion of Laponite and TiO2. TiO2nanoparticles were prepared by sol‐gel method and used as both the inorganic filler and multi‐functional crosslinking agent. The morphology of hydrogel was tuned as functions of the sodium hydroxide (NaOH) concentration and the ratio of Ti (mmol) to clay (g) (mmol Ti/g clay). SEM and HR‐TEM morphologies revealed that Laponite and TiO2tended to form a uniform and regular microstructure like peasecod in poly(acrylamide) (PAAm) matrix due to the synergistic effect between electrostatic interaction and covalent interaction when the concentration of NaOH used in TiO2hydrosol increased to 1 × 10−1mol/L. This homogeneous microstructure enhanced mechanical properties of hydrogel. The compression strength, modulus and fracture energy reached 2,107 kPa, 247 kPa, and 1,837 J/m2, respectively. The gels exhibited excellent fatigue resistance and good UV protective performance. It might have potential application in optical materials, wound dressing materials and tissue engineering scaffolds. POLYM. COMPOS., 40:E466–E475, 2019. © 2018 Society of Plastics Engineers