Borate driven heterogeneous networks for porous elastomers with improved tribological and mechanical performances

Porous polydimethylsiloxane (PDMS) elastomers produced using conventional phase separation methods often suffer from limited tribological and mechanical properties. In this study, we present a general approach for the fabrication of porous elastomers with borate-driven heterogeneous networks, which leverage the borate at the two-phase boundary to stabilize the phases, without the need for additives such as surfactants. Pure porous elastomers are created by removing the alcoholysis phases, with precisely controllable pore structure and mechanical performance. Interestingly, under saltwater lubrication, an atypical corrosion-lubrication phenomenon occurs on the porous elastomers, reducing the friction coefficient and wear rate by over 95 and 90%, respectively. Additionally, unique mechanical advantages, such as 1250% of stretch, were predictively imparted to the elastomers by various boric acid functional groups. Our method is generally applicable to various PDMS systems and offers a novel approach for designing pure porous materials for water-lubricated components and flexible sensors.