Compensation strategy for constructing high-performance aerogels using acrylamide-assisted vacuum drying and their use as water-induced electrical generators

Developing novel, energy-saving, and facile approaches to constructing high-performance aerogels is still chal-lenging. 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 degrees 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 mech-anism. 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.

Automated summary

In this study, high-performance aerogels were constructed using acrylamide as an assisting solute. By simple vacuum drying, aerogels with low density, high porosity, and low shrinkage were fabricated. The addition of acrylamide significantly increased the electrical conductivity of the aerogels.