Spreading of Dynamically Crosslinked Polydimethylsiloxane Drops

Abstract

Dynamically crosslinked polymer networks, characterized by non-permanent bonds, offer unique viscoelastic properties that can be used for various applications such as self-healing coatings and reusable adhesives. This study investigates the spreading behavior of a silicone polymer network with dynamic imine bonds, focusing on the relationship between material properties and spreading dynamics. We prepare polydimethylsiloxane (PDMS) networks with varied rheological properties by adjusting the ratio of amine and aldehyde groups and curing conditions. The spreading of PDMS spherical drops is investigated on surfaces with different surface energies, with the process quantified by measuring the contact length and height over time. Our findings reveal that higher modulus spheres spread more slowly, and that the spreading length increases more on high energy surfaces. This research could provide insights for developing coatings and adhesives with tunable properties by studying the interaction between transiently-crosslinked polymers and substrates during spreading.