Understanding and Controlling Polymer-Porous Solid Interactions for Polymer Upcycling*

Recent reports have shown that metal-functionalized high surface area porous materials can catalyze the deconstruction of various polymers. To enable efficient and selective polymer upcycling reactions, it is critical to understand and control the interactions between polymers and porous catalyst materials. In this presentation, I will describe our collaborative efforts to understand these interactions by modifying silica-based porous solids with atomic layer deposition (ALD). Based on capillary rise infiltration measurement of polyethylene and polystyrene into ALD-modified porous solids and calorimetry characterization of hexane and benzene adsorption onto such porous solids, we show that there is a strong correlation between the polymer-solid interfacial energy and the heat of gas adsorption. This trend is rationalized by calculating the interaction energy between small molecules and surfaces using density functional theory (DFT) calculations. Moreover, coarse-grained (CG) simulations also corroborate that the monotonic decreasing relationship between the polymer melt-solid interfacial tension and the solid-gas heat of adsorption. These new insights potentially provides guidelines on designing new catalyst materials for efficient polymer upcycling reactions.