Improving the Wetting Properties of PDMS/PVA-PEG Hydrophilic Sponges through the Addition of Wetting Agents

The optimization stage of the PDMS/PVA-PEG hydrophilic sponge has been prepared to increase water absorption, through the addition of wetting agents including bentonite, silicon oil, silica gel, and sodium hydrogen carbonate. The bentonite is purified by magnetic separation with a montmorillonite (MMT) content of approximately 33,17%. Silicon oil has hydrophilic properties due to the high surface energy of silicon dioxide, while silica gel is an adsorbent that will produce high silanol groups, and NaHCO3 is used to expand pores when releasing CO2. PDMS/PVA-PEG hydrophilic sponges were prepared with various ratios (w/w) PDMS: silicone oil: silica gel: NaHCO3: sponge). The sponge synthesis process is conducted by heating at a temperature of 110oC for 4 hours. The hydrophilic sponge composite incorporated bentonite in a ratio of 1:1 (w/w) to obtain VB1 sponge, VB2 sponge, and VB3 sponge have contact angle values 37.0 degrees, 56.6 degrees, and 58.8 degrees, respectively. NaHCO3 can increase the pore of the sponge, therefore the condition can increase the hydrophilicity. The contact angle of V1 sponge is 45.2 degrees, while VB1 is 37.0 degrees, which indicates that bentonite can enhance hydrophilic properties. Excellent wetting properties will imply good dewatering properties for hydrocarbon fuel refining.