Host-guest self-assembly grafts into silica sub-surface for shear-stable interfaces
Yizhe Liu, Yang Wu, Zishuai Wu, Keling Hu, Meirong Cai, Xiaowei Pei, Wenbo Sheng, Feng Zhou
Abstract
Aqueous lubrication materials are important in biological systems, but mimicking their properties outside of biological systems is challenging. Here, driven by obtaining shear-stable interfaces that mimic the articular cartilage, a “grafting-into” strategy is developed that allows host-guest self-assembly chemistry going deep into the sub-surface. Adamantane-terminal hydrophilic polymers can recognize β-cyclodextrins (CDs) embedded in silica sol network films through host-guest interaction and thus graft into the sub-surface. The introduction of the silica sol layer results in the promotion of surface load-bearing capacity by 300% while maintaining an ultra-low friction coefficient (∼0.006) and robust anti-fogging/anti-algae performances due to surface super-hydrophilicity. Based on noncovalent host-guest interactions, these characteristic functions can be recovered once the surface is worn. In addition, the method is universal and can realize photo-controllable reversible friction with an azobenzene-terminal hydrophilic polymer. This work presents an approach to prepare high-bearing supramolecular aqueous lubrication materials.