Preparation of Polyethylene Glycol Monoliths by Thermally Induced Phase Separation Method: Detailed Characterization Study and Investigation of Application

Polyethylene glycol (PEG) monoliths were prepared by thermally induced phase separation method (TIPS). Determining the solvent and non‐solvent is important for phase separation and morphological control of monoliths. Both single solvents (toluene, ethanol (EtOH), dimethyl sulfoxide (DMSO)) and solvent mixtures (EtOH:DMSO (1:1), EtOH: hexane (2:1), and EtOH: hexane (1:1)) were successful in performing phase separation. The porosity of the monoliths ranged up to 81%. The change in the polymer concentration and solvent ratio affected the monolith morphology. The monoliths have an average pore area of 0.59–1.62 μm 2 , average skeleton area of 0.30–0.97 μm 2 , with corresponding average pore and skeleton radius ranging from 1.57–2.29 μm and 1.65–2.50 μm, respectively. Nitrogen adsorption–desorption isotherms showed the monolith prepared using EtOH + hexane (2:1) had a large specific surface area of 53.8 m 2 /g. Crystallinity of the monoliths obtained from XRD data was consistent with the DSC. It was determined that a monolith can carry 85 times its own weight. The cloud point was found by visual turbidity method and the values varied between 25°C and 35°C. The “D distance” indicating the solvent quality was calculated using Hansen solubility parameters. Some of the monoliths were able to effectively absorb oils up to 3–3.5 times their own weight.