Polyimide (PI) aerogel has surfaced in research and development
as a result of its heat resistance, flame retardancy, and low dielectric
constant. However, it is still a challenge to reduce the thermal conductivity
while improving its mechanical strength and retaining hydrophobicity.
Herein, the PI/thermoplastic polyurethane (TPU) composite aerogel
was synthesized by coupling TPU with PI via a novel method of chemical
imidization combined with freeze-drying technology. With this technique,
PI aerogel with excellent comprehensive performance is produced. Interestingly,
the volume shrinkage of the composite aerogel decreased from 24.14
to 5.47%, which leads to low density (0.095 g/cm3) and
elevated porosity (92.4%). In addition, strong mechanical strength
(1.29 MPa) and high hydrophobicity (123.6°) were achieved. More
importantly, PI/TPU composite aerogel demonstrated a low thermal conductivity
of 29.51 mW m–1 K–1 at ambient
temperature. Therefore, PI/TPU composite aerogel can be a promising
material for hydrophobic and thermal insulation applications.
Carbon aerogel (CA) based materials have multiple advantages, including high porosity, tunable molecular structures, and environmental compatibility. Increasing interest, which has focused on CAs as electrocatalysts for sustainable applications including oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and CO2 reduction reaction (CO2RR) has recently been raised. However, a systematic review covering the most recent progress to boost CA-based electrocatalysts for ORR/OER/HER/CO2RR is now absent. To eliminate the gap, this critical review provides a timely and comprehensive summarization of the applications, synthesis methods, and principles. Furthermore, prospects for emerging synthesis, screening, and construction methods are outlined.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.