Textile clothing coated with silica aerogels has the potential of thermal insulation performance for heating and cooling. This work investigated the thermal isolation properties of untreated and treated three-layered weft-knitted spacer fabrics with different thicknesses (2 mm, 3 mm, and 4 mm) by using silica aerogels. Three samples of spacer fabrics (300GSM, 350GSM, 540GSM) were coated with nanoporous silica aerogel at a 26°C temperature and then kept for aging, exchanging the solvent, surface modification. The characteristics, for example, thermal resistance, thermal conductivity, yarn arrangement angle, porosity, and air permeability of spacer fabric samples, were investigated. Scanning electron microscopy analysis and Fourier transform infrared spectroscopy–attenuated total reflection test were conducted to explore the surface morphology and surface changes initiated by the silica coating. The experimental results indicated that the treated weft-knitted spacer fabrics with 350GSM have a higher thermal resistance of 0.09131 m2 K W−1, higher porosity ratio, higher air permeability, higher arrangement angle, and lower density. The statistical analysis also verified the significant performance (p = 0.000) of treated fabric samples at the 0.05 level.

The interest in multifunctional textile materials has been increased due to the health and safety measures of living beings, especially in severe conditions. Therefore, this study investigated the hydrophobicity, oil sorption capacity, and bending properties of untreated or uncoated and treated or coated 3D weft-knitted spacer fabric samples (92% polyester/8% spandex), i.e. sample 1, sample 2, and sample 3, having thicknesses of 2 mm (300 gm−2), 3 mm (350 gm−2), and 4 mm (540 gm−2), with silica aerogels (SAs) through the sol-gel method. SEM, FTIR-ATR, and surface roughness test of fabric samples were analyzed to comprehend the influence of SAs. The experimental results revealed the excellent hydrophobicity and oleophilicity of all the treated 3D weft-knitted spacer fabric samples, providing a higher water contact angle (CA) 142 ± 0.84° and an oil sorption capacity 7.51 ± 0.08g/g and 6.88 ± 0.06g/g for vegetable oil and engine oil, especially of sample 2 owing to the most silica particles. The statistical analysis also demonstrated a significant performance (P < 0.05) of treated spacer fabric samples at the 0.05 level. Thus, these fabrics are suitable for an industrial application of hydrophobic and oleophilic properties.

With increasing industrial development, frequent oil spillages in water; therefore, it is imperative and challenging to develop absorbents materials that are eco-efficiency, cost-effective, and pollution prevention. In this study, sorbents obtained from Lignin incorporated with Polypropylene in different levels loading 0, 10, 20 % wt using thermally induced phase separation Technique (TIPS). The Polypropylene/Lignin blend monoliths were fabricated and compared in terms of morphological, thermal, and wetting characterizations. The successfully blending of different lignin concentrations with preserved the chemical structure of the polymer was confirmed by FTIR analysis. Thermogravimetric tests displayed that the existence of Lignin has changed the onset temperature (Tonset) of the blending sorbents, decreasing as the loading of Lignin is increased. The contact angle measurement showed a decrease in the hydrophobicity of sorbents with increasing lignin loading, Polypropylene/Lignin blend monoliths showed better absorption toward oils (soybean – engine) as compared to Polypropylene itself. PP10L showed an improvement in the oil sorption capacity around 2 times compared to the Polypropylene. These excellent features make Polypropylene/Lignin blend monoliths more competitive promising candidates than commercial absorbent.

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.