Abstract Polymer membranes are critically important to the advancement of next generation technologies in energy devices, water purification, and industrial separations. Understanding relationships between membrane structure, physical properties, and transport phenomena is critical to developing next-generation membranes for applications that require the selective transport of neutral and ionic molecules. Fractional free volume (FFV) is one critical membrane characteristic in dense polymer membranes as it forms the pathways for molecular transport. Here, we investigate the impact of varied FFV on the transport of methanol, sodium acetate, and their mixture in a series of polyethylene glycol diacrylate (PEGDA, n = 13) membranes prepared with a range of FFV. Membranes are fabricated by UV-photopolymerization where FFV is varied through control of the water content in pre-polymerization solutions. Water uptake of fabricated membranes is characterized as a proxy for the varying FFV. Solute permeabilities are measured in custom-built diffusion cells for methanol, sodium acetate and their mixture with downstream receiver cell solute concentrations measured via in situ attenuated total reflectance Fourier transform infrared (ATR FTIR) spectroscopy. Membrane permeability varied by up to a factor of 6 as the prepolymerization water content, and thereby FFV, of the membranes was varied. Furthermore, distinct, and increasing, differences in the magnitude of extracted permeabilities between single solute and combined solute experiments are observed as the FFV increases and these differences are attributed to a combination of assisted and competitive transport.

中文翻译：

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甲醇和醋酸钠在不同自由体积分数的聚（乙二醇）二丙烯酸酯膜中的多组分传输

摘要 聚合物膜对于能源设备、水净化和工业分离等下一代技术的进步至关重要。了解膜结构、物理特性和传输现象之间的关系对于为需要选择性传输中性和离子分子的应用开发下一代膜至关重要。自由体积分数 (FFV) 是致密聚合物膜中的一项关键膜特性，因为它形成了分子传输的途径。在这里，我们研究了不同 FFV 对甲醇、乙酸钠及其混合物在一系列用一系列 FFV 制备的聚乙二醇二丙烯酸酯 (PEGDA, n = 13) 膜中的传输的影响。膜是通过紫外线光聚合制造的，其中 FFV 通过控制预聚合溶液中的水含量来改变。制成的膜的吸水量被表征为变化的 FFV 的代表。溶质渗透率在甲醇、醋酸钠及其混合物的定制扩散池中测量，下游接收池溶质浓度通过原位衰减全反射傅里叶变换红外 (ATR FTIR) 光谱测量。随着预聚合水含量的变化，膜渗透率的变化高达 6 倍，因此膜的 FFV 发生变化。此外，明显且不断增加，