regulation of reaction kinetics

反应动力学调节
  • 文章类型: Journal Article
    微观结构的精确操纵(孔径,自由体积分配,和自由体积元素的连通性),膜的厚度和机械特性对于促进在化学工业中复杂的分子筛分应用中有效利用自立膜具有至关重要的意义。在这一贡献中,我们首先报道了两种创新的酯连接共价有机骨架(COF)膜的合成,通过选择植物衍生的鞣花酸和槲皮素酚类单体以及对苯二甲酰氯作为结构单元而产生。这两种自立的微观结构的优化,通过应用三种不同的界面电场系统,系统地实现了植物衍生的COF膜:电中性(不含表面活性剂),正电(带正电荷的表面活性剂)和负电(带负电荷的表面活性剂)。观察到带正电荷的系统促进了膜形成速率的创纪录增加,与在电中性和负电荷条件下形成的膜相比,产生具有均匀孔径和增强的柔性的更致密的膜。这种改进主要归因于库仑力和表面活性剂在正己烷/水界面处的均匀取向。此外,确定了相关性,其中表面活性剂的烷基链长度的增加导致更均匀的孔径和COF膜的分子量截止值(MWCO)的降低,这归因于疏水性微环境的形成,导致存在较少的水分子。当表面活性剂链长持续增加时,膜孔径增加。所得的COF膜表现出前所未有的高透水性组合,对小分子具有卓越的筛分能力,强大的机械强度,化学稳健性和耐氯性,为有前途的膜分离科学和技术。本文受版权保护。保留所有权利。
    The precise manipulation of the microstructure (pore size, free volume distribution, and connectivity of the free-volume elements), thickness, and mechanical characteristics of membranes holds paramount significance in facilitating the effective utilization of self-standing membranes. In this contribution, the synthesis of two innovative ester-linked covalent-organic framework (COF) membranes is first reported, which are generated through the selection of plant-derived ellagic acid and quercetin phenolic monomers in conjunction with terephthaloyl chloride as a building block. The optimization of the microstructure of these two COF membranes is systematically achieved through the application of three different interfacial electric field systems: electric neutrality, positive electricity, and negative electricity. It is observed that the positively charged system facilitates a record increase in the rate of membrane formation, resulting in a denser membrane with a uniform pore size and enhanced flexibility. In addition, a correlation is identified wherein an increase in the alkyl chain length of the surfactants leads to a more uniform pore size and a decrease in the molecular weight cutoff of the COF membrane. The resulting COF membrane exhibits an unprecedented combination of high water permeance, superior sieving capability, robust mechanical strength, chemical robustness for promising membrane-based separation science and technology.
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  • 文章类型: Journal Article
    具有快速制备的高度柔性和坚固的自支撑共价有机骨架(COF)膜对于实现精确分离是重要的,但在技术上具有挑战性。在这一贡献中,我们首先报告了一种新颖的基于亚胺的2D软共价有机框架(SCOF)膜,该膜具有226.9cm2的大面积,通过巧妙地选择醛柔性接头和三角形结构单元。基于在水/二氯甲烷(DCM)界面构建的十二烷基硫酸钠(SDS)分子通道,快速形成软2D共价有机框架膜(约5分钟),这是创纪录的快速SCOF膜形成,比文献报道的快72倍。MD模拟和DFT计算阐明了动态,自组装SDS分子通道促进胺单体在本体中更快、更均匀的转移,从而形成具有更均匀孔隙的软2D自立式COF膜。形成的SCOF膜对小分子表现出极好的筛分能力,在(I)强碱性(5mol/LNaOH)中的稳健性,(二)酸(0.1mol/LHCl),和(III)各种有机溶液,和足够的灵活性,具有2000m-1的大曲率,用于膜分离科学技术。本文受版权保护。保留所有权利。
    Highly flexible and robust self-standing covalent organic framework (COF) membranes with rapid preparation are important but technically challenging for achieving precise separation. Herein , a novel imine-based 2D soft covalent organic framework (SCOF) membrane with a large area of 226.9 cm2 , via ingeniously selecting an aldehyde flexible linker and a trigonal building block, is reported. The soft 2D covalent organic framework membrane is rapidly formed (≈5 min) based on the sodium dodecyl sulfate (SDS) molecular channel constructed at the water/dichloromethane (DCM) interface, which is the record-fast SCOF membrane formation and 72 times faster than that in the reported literature. MD simulation and DFT calculation elucidate that the dynamic, self-assembled SDS molecular channel facilitates faster and more homogeneous transfer of amine monomers in the bulk, thereby forming a soft 2D self-standing COF membrane with more uniform pores. The formed SCOF membrane exhibits superb sieving capability for small molecules, robustness in strong alkaline (5 mol L-1 NaOH), acid (0.1 mol L-1 HCl), and various organic solutions, and sufficient flexibility with a large curvature of 2000 m-1 for membrane-based separation science and technology.
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