Superhydrophobic Solution Blow Spinning PTFE–SiO2 Composite Membranes for Enhanced Liquid–Liquid Extraction

Abstract

An ultrafine-fibrous polytetrafluoroethylene (PTFE)–SiO2 membrane was successfully fabricated using the solution blow spinning (SBS) method. This membrane demonstrated superhydrophobicity (water contact angle > 150°) and oleophilicity (ethyl acetate contact angle = 0°) compared to a commercial PTFE membrane. Additionally, the SBS PTFE–SiO2 membrane exhibited a high porosity of 83% compared to 55% in the commercial PTFE membrane. When used for membrane-assisted extraction, the PTFE–SiO2 membrane exhibited a higher caffeine transport rate (3.84 × 10−7 m s−1) than the commercial PTFE membrane (2.18 × 10−7 m s−1). The addition of SiO2 nanoparticles provided better hydrophobicity and higher phase stability during membrane-assisted solvent extraction. Given the excellent thermal and chemical stability of PTFE–SiO2, this type of membrane shows potential for high-value solvent extraction and stable long-term operation with no emulsion generation. The SBS method offers a promising alternative for the sustainable fabrication of PTFE membranes on a larger scale without the need for organic solvents or lubricants.