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用于精确分子筛分的超薄膜中的大环孔排列策略
作者:小柯机器人 发布时间:2022/9/3 14:48:33

英国帝国理工大学Livingston, Andrew G.团队报道了用于精确分子筛分的超薄膜中的大环孔排列策略。相关研究成果发表在2022年8月31日出版的国际知名学术期刊《自然》。

聚合物膜广泛用于分离过程,包括脱盐、有机溶剂纳米过滤和原油分馏。然而,由于聚合物中定义不清的空隙的分子波动,亚纳米孔的直接证据和控制其尺寸的可行方法仍然具有挑战性。具有固有空腔的大环可能会解决这一挑战。然而,具有不可区分反应性的未官能化大环在数百纳米厚的膜中趋向于无序堆积,阻碍了空腔互连和通孔的形成。

该文中,研究人员合成了具有不同反应性的选择性官能化大环,这些大环优先排列以在超薄纳米膜上形成定义良好的孔。通过将纳米膜厚度减小到几纳米,增强了有序结构。这种定向结构使纳米膜表面的亚纳米级大环孔能够直接可视化,其尺寸通过改变大环特性来适应ngstrm精度。与无序膜相比,对齐的大环膜具有两倍的甲醇渗透性和更高的选择性。在高值分离中,例如通过富集大麻酚油,实现了一个数量级的乙醇运输,比商业最先进的膜高出三倍。

该方法为在聚合物膜中创建亚纳米通道提供了一种可行的策略,并证明了它们在精确分子分离方面的潜力。

附:英文原文

Title: Aligned macrocycle pores in ultrathin films for accurate molecular sieving

Author: Jiang, Zhiwei, Dong, Ruijiao, Evans, Austin M., Biere, Niklas, Ebrahim, Mahmood A., Li, Siyao, Anselmetti, Dario, Dichtel, William R., Livingston, Andrew G.

Issue&Volume: 2022-08-31

Abstract: Polymer membranes are widely used in separation processes including desalination1, organic solvent nanofiltration2,3 and crude oil fractionation4,5. Nevertheless, direct evidence of subnanometre pores and a feasible method of manipulating their size is still challenging because of the molecular fluctuations of poorly defined voids in polymers6. Macrocycles with intrinsic cavities could potentially tackle this challenge. However, unfunctionalized macrocycles with indistinguishable reactivities tend towards disordered packing in films hundreds of nanometres thick7,8,9, hindering cavity interconnection and formation of through-pores. Here, we synthesized selectively functionalized macrocycles with differentiated reactivities that preferentially aligned to create well-defined pores across an ultrathin nanofilm. The ordered structure was enhanced by reducing the nanofilm thickness down to several nanometres. This orientated architecture enabled direct visualization of subnanometre macrocycle pores in the nanofilm surfaces, with the size tailored to ngstrm precision by varying the macrocycle identity. Aligned macrocycle membranes provided twice the methanol permeance and higher selectivity compared to disordered counterparts. Used in high-value separations, exemplified here by enriching cannabidiol oil, they achieved one order of magnitude faster ethanol transport and threefold higher enrichment than commercial state-of-the-art membranes. This approach offers a feasible strategy for creating subnanometre channels in polymer membranes, and demonstrates their potential for accurate molecular separations.

DOI: 10.1038/s41586-022-05032-1

Source: https://www.nature.com/articles/s41586-022-05032-1

期刊信息

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:42.778
官方网址:http://www.nature.com/