Construction and tribological properties of poly acrylic acid-poly(3-(methacryloylamino)propyl) dimethyl(3-sulfopropyl)ammonium hydroxide hydrogel coatings embedded with SiO2 nanoparticles on Ti6Al4V substrate

The development of highly effective bio-lubricant coatings for arthritis treatment is extremely demanded. Herein, inspired by the efficient lubrication of articular cartilage, acrylic acid (AA) with (3-(methacryloylamino) propyl) dimethyl (3-sulfopropyl) ammonium hydroxide (MPDSAH) hydrogel coatings containing nanoparticles on Ti6Al4V substrate were designed and fabricated via UV grafting technology. SiO 2 and SiO 2 grafted with PAA polymer brushes (SiO 2 -g-PAA) were separately doped into the PAA-PMPDSAH hydrogel. The PAA-PMPDSAH/SiO 2 -g-PAA exhibits good tensile and compressive properties compared with PAA-PMPDSAH/SiO 2 hydrogel, with an enhancement of 183.4% in tensile modulus and 60.8% in compressive modulus. The PAA-PMPDSAH/SiO 2 -g-PAA hydrogel coatings exhibit a low wear volume, 2.9 ± 0.16 × 10 6 μm 3 , representing a decline of 32.1% and 61.3% compared with the PAA-PMPDSAH and PAA-PMPDSAH/SiO 2 hydrogel coatings, respectively. The antiwear performance has obviously improved. The hydrophilic PAA polymer brushes prevent the agglomeration of nanoparticles and promote homogeneously dispersion within the hydrogel. The three-dimensional crosslinked network structure of hydrogel effectively protects the structural integrity of the polymer brushes, thereby facilitating enduring lubrication properties. This work provides a strategy for promising artificial joint lubrication in biomedical fields.