(751d) Burn-Dry: Aerogel Fabrication By Polymer-Assisted Rapid Thermal Annealing

Aerogels, comprised of a microporous solid in which the dispersed phase is a gas, are desired for a broad range of emerging applications, such as super insulation and energy-saving. These rising needs highlight the importance of developing a simpler, scalable strategy for aerogel fabrication that by-passes uneconomical steps, including long thermal treatments, etching, and freeze-drying. In this work, we leverage rapid thermal annealing (RTA) to fabricate reduced graphene oxide (rGO) aerogel as a new “burn-dry” method that is more efficient and potentially applicable to various materials. The RTA is a classic method in the semiconductor industry to dope silicon by heating up wafers high temperatures (over 1000 °C) at a very fast rate (up to ~150 °C/s). Unlike extensive research on semiconductors, applications of RTA to polymers are less explored, perhaps because the thermophysical properties of polymers under such high heating rates are not well understood. Polymer-assisted RTA can be considered as a burn-dry, as opposed to freeze-drying, which freezes structure by quenching and removing solvent with tedious steps. In contrast, polymer-assisted RTA quickly burns polymer away, thereby preventing molecular rearrangement to freeze the structure. We hypothesize that the very fast heating rates of RTA can kinetically arrest the co-continuous structures to template a model hard material, rGO. This simple, fast, energy-efficient technique has already been employed in the semiconductor and solar cell industry, making it versatile, highly scalable, and economically viable. This presentation will discuss the relationship between heating rate and phase separation kinetics of a model polymer blend with rGO and resulting morphology.