Hydrophobic and oleophilic 3D weft-knitted spacer fabrics coated by silica aerogels with five different concentrations

Abstract

Silica aerogels were made from tetraethylorthosilicate by the sol-gel method and coated on the 3D weft-knitted spacer fabrics (WKSFs) to compare the interaction of the silica aerogel coating with five various concentrations. SEM, FTIR-ATR, surface roughness, surface energy, and BET analysis were used to observe and characterize the surface morphology, molecular interaction, surface changes, surface tension, and specific surface area of fabric samples or sorbents. Consequently, this study investigated the wettability, oil absorption capacity, oil retention capacity, and reusability of untreated and treated 3D WKSF sorbents. The outcomes exposed the excellent hydrophobic and oleophilic properties of all treated 3D WKSF sorbents, showing a greater water contact angle of 145.1 ± 0.42°, and an oil absorption and retention capacity of (7.87 ± 0.09 g/g and 7.53 ± 0.06 g/g) and (89.98 ± 0.79% and 92.48 ± 0.56%) for vegetable oil and engine oil, respectively, with notable reusability, most particularly for sorbent 5, due to the higher silica aerogel add-on %, pore diameter, and pore volume. The findings verified that the chemical composition and fabric structure played an important role in the tremendous hydrophobic and oleophilic behavior. The statistical study on specific surface area, pore diameter, pore volume, surface roughness, water contact angle, oil contact angle, oil absorption capacity, and oil retention capacity also revealed that treated fabrics performed significantly ( p < 0.05) in hydrophobic and oleophilic features at the 0.05 level. Hence, these fabrics can be used in industrial usages that need hydrophobic and oleophilic qualities.