Chitin-augmented wetting resistance and water-in-oil emulsion separation performance of silane-modified polyketone membrane

The utilization of membrane technology for separating water-in-oil (W/O) emulsions necessitates a membrane possessing high hydrophobic properties. However, the use of naturally hydrophobic membrane materials, such as polyvinylidene fluoride, is undesirable due to the persistence of fluorine-containing compounds in the environment. Polyketone (PK) membranes present a potential alternative, but their inherent hydrophilic properties can hinder the W/O emulsion separation process. To address this issue, hydrophobic modification of PK membranes can improve their performance in separating W/O emulsion. Natural hydrophobic materials like chitin offer a more sustainable alternative compared to synthetic materials. Chitin was introduced onto the membrane surface along with hexadecyltrimethoxysilane (HDTMS) subsequent to the initial reaction of the PK membrane with tetraethyl orthosilicate (TEOS). Comparative analysis revealed that the mixed chitin and HDTMS modification resulted in the lowest surface wettability compared to membrane modification using only TEOS, HDTMS, and chitin. Examination of membrane performance through toluene emulsion separation demonstrated increased permeability after modification, with permeate toluene purity over 99.8 %. Additionally, the chitin and silanemodified PK membrane exhibited a two-fold increase in filtration process permeability, indicating outstanding fouling resistance. These findings underscore the potential of natural compounds in imparting desired hydrophobic properties to membranes while minimizing reliance on synthetic materials.