Preparation of superoleophobic coalescence filter materials based on a two-step process and oil mist filtration performance optimization

Abstract

Coalescence filter elements composed of fibrous materials can effectively remove oil mist from gas stream. Recent studies have demonstrated that wettability is a critical factor influencing the coalescence filtration performance of filter media. Superoleophobic materials have attracted attention from researchers due to their remarkable oil-repellent properties. In this study, glass fiber materials were used as the substrate, and a home-made modified solution was applied using a combined two-step process of immersion and spraying to produce superoleophobic filter media with a contact angle exceeding 150° for DEHS droplets, other structural parameters of the filter media were not altered. Furthermore, the modified superoleophobic filter media prepared by the two-step process were compared to filter media modified by using different methods. The results show that the filter media prepared by the two-step process show excellent and stable superoleophobicity. After incorporating a strip-patterned treatment, the filtration efficiency for oil mist particles larger than 40 nm was improved from 89.13 % to 94.77 %, while the steady-state pressure drop was reduced by 46.59 % compared to the oleophilic substrate.