Zhou Yiding, Zhu Mengze, Sun Yuanyuan, Zhu Yun, Zhang Shengmiao
Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
ACS Macro Lett. 2023 Mar 21;12(3):302-307. doi: 10.1021/acsmacrolett.2c00712. Epub 2023 Feb 13.
Emulsion-templated porous polymers have attracted broad attention due to their great application prospects in many fields. However, scaling up the emulsion-templated technique from the lab to industrial production remains a great challenge, especially for systems involving an oil-in-water (o/w) emulsion template that is used normally for preparing hydrophilic porous polymers. These systems require large amounts of organic solvents to be the internal phase (i.e., major phase) of the emulsion templates, which causes a significant environmental impact and cost. Herein, a water-in-water (w/w) emulsion-templated technique is presented to prepare porous hydrophilic polymers. The w/w emulsion is prepared by mixing a PEG aqueous solution and a dextran aqueous solution with cellulose nanocrystals (CNCs) as a stabilizer. With varying the mass ratio of dextran/PEG in the range of 1/2 to 8/1, a series of dextran-rich-phase-in-PEG-rich-phase (dextran/PEG) emulsions are obtained. Subsequently, monomers, such as acrylamide, acrylic acid, and/or 2-acrylamido-2-methylpropanesulfonic acid, are introduced to the emulsions to fabricate porous hydrophilic polymers. These polymers have an open-cell structure like those of o/w emulsion-templated polymers. The system developed herein is an environmentally friendly, low cost, and universal emulsion-templated method toward porous hydrophilic polymers, which avoids the defects caused by the presence of large amounts of organic solvents in an o/w emulsion-templating method and can be moved from the lab to industrial-scale production.
乳液模板法制备的多孔聚合物因其在许多领域的巨大应用前景而受到广泛关注。然而，将乳液模板技术从实验室规模扩大到工业生产仍然是一个巨大的挑战，特别是对于涉及水包油（o/w）乳液模板的体系，该模板通常用于制备亲水性多孔聚合物。这些体系需要大量有机溶剂作为乳液模板的内相（即主要相），这会对环境造成重大影响并增加成本。在此，我们提出了一种水包水（w/w）乳液模板技术来制备多孔亲水性聚合物。通过将聚乙二醇（PEG）水溶液和葡聚糖水溶液与纤维素纳米晶体（CNCs）作为稳定剂混合来制备w/w乳液。在葡聚糖/PEG的质量比在1/2至8/1范围内变化时，可获得一系列富含葡聚糖相在富含PEG相中的（葡聚糖/PEG）乳液。随后，将丙烯酰胺、丙烯酸和/或2-丙烯酰胺基-2-甲基丙烷磺酸等单体引入乳液中，以制备多孔亲水性聚合物。这些聚合物具有与o/w乳液模板聚合物类似的开孔结构。本文开发的体系是一种环境友好、低成本且通用的制备多孔亲水性聚合物的乳液模板法，它避免了o/w乳液模板法中大量有机溶剂存在所导致的缺陷，并且可以从实验室规模扩大到工业规模生产。
