Dhameri Sulaiman, Imam Ibrahim A, Abbas Usman, Stallings Jason, Ewah Odianosen, Shao Qing, Chwatko Malgorzata
Chemical and Materials Engineering Department, Pigman College of Engineering, University of Kentucky, Lexington, Kentucky 40506, United States.
ACS Omega. 2025 Aug 13;10(33):38112-38121. doi: 10.1021/acsomega.5c05469. eCollection 2025 Aug 26.
The upper critical solution temperature (UCST) of binary polymer-solvent blends can create porous structures for many applications, including filtration. This study investigates how UCST can be tuned in a non-aqueous system of polystyrene and terpineol. The addition of small molecules, γ-valerolactone, oleic acid, and limonene, was tested to modify the terpineol-polystyrene phase separation temperature. The resulting porous structures were studied to determine the pore size, porosity, water flux, and rejection of test molecules to better understand the impact of the additives on both the processing temperature and porous materials' properties. The study found that the hydrogen bond propensity and miscibility of the additives significantly affected the UCST. A change of over 35 °C was observed when the additive concentration varied from 0 to 15 wt %, and the transition temperature increased or decreased depending on the additive solvent strength. The surface pore diameter was significantly altered, but the bulk pore diameter remained similar in all cases with the exception of oleic acid. The addition of small-molecule addives offers a way to control the UCST by tunning addities' solubilities and hydrogen bonding abilities in similar blends, toward lower energy use porous film synthesis.
二元聚合物 - 溶剂共混物的上临界溶液温度（UCST）可为包括过滤在内的许多应用创造多孔结构。本研究探讨了如何在聚苯乙烯和松油醇的非水体系中调节UCST。测试了添加小分子γ - 戊内酯、油酸和柠檬烯对松油醇 - 聚苯乙烯相分离温度的影响。对所得多孔结构进行了研究，以确定孔径、孔隙率、水通量和对测试分子的截留率，从而更好地了解添加剂对加工温度和多孔材料性能的影响。研究发现，添加剂的氢键倾向和混溶性对UCST有显著影响。当添加剂浓度从0 wt%变化到15 wt%时，观察到超过35°C的变化，且转变温度根据添加剂的溶剂强度而升高或降低。表面孔径有显著改变，但除油酸外，所有情况下的整体孔径保持相似。添加小分子添加剂提供了一种通过调节添加剂在类似共混物中的溶解度和氢键能力来控制UCST的方法，以实现低能耗多孔膜的合成。
