Guo Hukang, Li Fupeng, Shui Xuerong, Wang Jianyu, Fang Chuanjie, Zhu Liping
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, P.R. China.
MOE Engineering Research Center of Membrane and Water Treatment Technology, Zhejiang University, Hangzhou 310058, P.R. China.
ACS Appl Mater Interfaces. 2023 Aug 2;15(30):37077-37085. doi: 10.1021/acsami.3c07440. Epub 2023 Jul 21.
Organic solvent nanofiltration (OSN) technology shows reduced energy consumption by almost 90% with great potential in achieving low-carbon separation applications. Polyamide nanofilms with controlled intrinsic and extrinsic structures (e.g., thickness and porosity) are important for achieving such a goal but are technically challenging. Herein, ultrathin polyamide nanofilms with controlled microporosity and morphology were synthesized via a molecular layer deposition method for OSN. The key is that the polyamide synthesis is controlled in a homogenous organic phase, rather than an interface, not only involving no monomer kinetic diffusion but also broadening the applicability of amine monomers. The particular nonplanar and rigid amine monomers were superbly used to increase microporosity and the nanofilm was linearly controlled at the nanometer scale to decrease thickness. The composite membrane with the polyamide nanofilms as separation layers displayed highly superior performance to current counterparts. The ethanol and methanol permeances were up to 5.5 and 14.6 L m h bar, respectively, but the molecular weight cutoff was tailored as low as 300 Da. Such separation performance remained almost unchanged during a long-term operation. This work demonstrates a promising alternative that could synergistically control the physicochemical structures of ultrathin selective layers to fabricate high-performance OSN membranes for efficient separations.
有机溶剂纳滤（OSN）技术显示出能耗降低了近90%，在实现低碳分离应用方面具有巨大潜力。具有可控的内在和外在结构（如厚度和孔隙率）的聚酰胺纳米膜对于实现这一目标很重要，但在技术上具有挑战性。在此，通过分子层沉积法合成了具有可控微孔率和形态的超薄聚酰胺纳米膜用于有机溶剂纳滤。关键在于聚酰胺的合成是在均相有机相中控制的，而不是在界面处，这不仅不涉及单体动力学扩散，还拓宽了胺单体的适用性。特别的非平面刚性胺单体被出色地用于增加微孔率，并且纳米膜在纳米尺度上被线性控制以减小厚度。以聚酰胺纳米膜作为分离层的复合膜表现出比目前同类产品优越得多的性能。乙醇和甲醇的渗透率分别高达5.5和14.6 L m h bar，但截留分子量被调整至低至300 Da。在长期运行过程中，这种分离性能几乎保持不变。这项工作展示了一种有前景的替代方案，它可以协同控制超薄选择性层的物理化学结构，以制造用于高效分离的高性能有机溶剂纳滤膜。
