Hydrophobic Phenolic/Silica Hybrid Aerogels for Thermal Insulation: Effect of Methyl Modification Method.

ABSTRACT: Hydrophobic phenolic/silica hybrid aerogels were synthesized via different methyl modification methods including in situ polymerization (RA-IS), surface grafting (RA-SG), and vapor deposition (RA-VD). All the methods achieved good hydrophobicity, with a water contact angle around 140°, and the hydrophobic mechanisms were clarified. RA-IS possesses the highest specific surface area and nanopore volume, and the lowest bulk density. Therefore, it exhibits much lower thermal conductivity (32.2 mW·m^-1·K^-1) at 25 °C than RA-SG, RA-VD and other reported phenolic/silica hybrid aerogels. The compression strength (3.3 MPa) and Young's modulus (19.2 MPa) of RA-IS are higher than those of its state-of-the-art counterparts. The methyl groups in RA-IS are linked in the matrix by a

SUBMITTER: Nie M 

PROVIDER: S-EPMC12841154 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature