Application of a new thermodynamic model to the swelling behaviour of poly(N-isopropylacrylamide) gels in aqueous solutions of alcohols

新的热力学模型在醇水溶液中聚（N-异丙基丙烯酰胺）凝胶溶胀行为的应用

• 批准号: 272101716
• 负责人: Professor Dr. Jörg Kreßler, since 4/2016
• 金额: --
• 依托单位: Arbeitsbereich Physikalische und Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/272101716?language=en
• 关键词: Application; new; thermodynamic; model; swelling

Three dimensional cross linked poly (N-isopropylacrylamide) (PNIPAM) forms non-ionic and thermo-sensitive hydrogels that have been experimentally studied very thoroughly. Cooling the gel there is a transition from a shrunken to a strongly swollen state at approximately 32°C. Because of the convenient transition temperature these hydrogels have found a wide range of medical applications, including controlled drug delivery systems, artificial blood vessels and muscles as well as contact lenses. In the classical swelling theory a gel is an infinitely large cross-linked polymer molecule that encages the solvent molecules. A new model is based on swelling equilibria and permits many cross-linked polymer molecules that encage different amounts of solvent. Until now, this model was applied only to the swelling behaviour of PNIPAM in pure water using a simple expression for the Helmholtz energy. Here, this expression is to be improved by incorporation of chemical association models. Furthermore, the model is to be extended to the case of two solvents (in detail: swelling of PNIPAM in mixtures of water and an alcohol). In this, the main goal is the calculation of the swelling degree as function of the temperature and of the composition of the solvent mixture.

三维交联聚（N-异丙基丙烯酰胺）（PNIPAM）形成非离子和热敏水凝胶，已通过实验进行了非常彻底的研究。冷却凝胶时，大约 32°C 时凝胶会从收缩状态转变为强烈溶胀状态。由于转变温度方便，这些水凝胶具有广泛的医疗应用，包括受控药物输送系统、人造血管和肌肉以及隐形眼镜。在经典溶胀理论中，凝胶是包围溶剂分子的无限大的交联聚合物分子。一种新模型基于溶胀平衡，允许许多交联聚合物分子容纳不同量的溶剂。到目前为止，该模型仅使用亥姆霍兹能量的简单表达式应用于纯水中 PNIPAM 的溶胀行为。在这里，这种表达将通过结合化学缔合模型来改进。此外，该模型将扩展到两种溶剂的情况（具体来说：PNIPAM 在水和酒精的混合物中溶胀）。在此，主要目标是计算作为温度和溶剂混合物组成的函数的溶胀度。