UC Davis

Developing novel, energy-saving, and facile approaches to constructing high-performance aerogels is still challenging. Aerogels are most commonly produced by freeze-drying and supercritical drying that require expensive specialty equipment or ambient drying lengthily of solvent exchange precursors. Here, we report a compensation strategy using acrylamide as an assisting solute to enable the construction of conductive polymer aerogels by simple vacuum drying of frozen solids of aqueous poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS). In this approach, the acrylamide crystal sublimates slowly at an elevated temperature (80 or 110 °C) to maintain the porous structure of PEDOT/PSS in the solid-state during water evaporation. By tuning PEDOT/PSS to acrylamide weight ratios and drying temperatures, aerogels were produced with low density (6.3–21.6 mg/cm3), high porosity (>99 %), and low shrinkage (5.3 %). Additionally, acrylamide increases the electrical conductivity of PEDOT/PSS by three orders of magnitude (from 0.01 to 81.1 S/m). Morphology and physical properties are further analyzed to reveal aerogel formation and the conductivity enhancement mechanism. These aerogels are then applied as water-induced electric generators for green energy harvesting. The current work provides an alternative and simplified approach to rapidly fabricating various nanomaterial-based aerogels, replacing the slower and more expensive freeze-drying and supercritical drying.