The preparation of hydrophobic alginate-based fibrous aerogel and its oil absorption property

In order to obtain hydrophobic alginate-based fibrous aerogel, sodium alginate (SA) and acrylamide (AM) as raw materials, methyltrimethoxysilane (MTMS) as surface modification agent. And, hydrophobic alginate-based fibrous aerogel was prepared by soaking sodium alginate / polyacrylamide (PAM) composite hydrogel with methyltrimethoxysilane / ethyl orthosilicate (TEOS) / ethanol mixture. The samples were systematically characterized by SEM, FT-IR, DSC, and so on. The results manifested that the hydrophobic groups successfully introduced into the aerogel, made aerogel possess hydrophobicity, Ca²⁺ was uniformly dispersed in the aerogel by Ca²⁺ slow-release crosslinking method. The prepared aerogel showed macroporous and mesoporous microstructure. The bulk density was 0.026 g/cm³, specific surface area was 80 m²/g, the average mesoporous size was 13.18 nm, the average macropore size was 2.25 µm, the total pore area was 39 m²/g, the porosity was 95.6% and the single point total pore volume was 0.528 cm³/g. The hydrophobic alginate-based fibrous aerogel had excellent oil absorption, the adsorption capacity was 65 times as much as its own weight.