porous liquid

多孔液体
  • 文章类型: Journal Article
    III型多孔液体(PL)由分散在尺寸排除的液相中的多孔固体颗粒组成,并且作为用于诸如气体分离的应用的新型介质吸引了很多关注。然而,颗粒大小等基本变量对其物理性质的影响目前在很大程度上是未知的。在这里,我们研究了基于固体Al(OH)(富马酸酯)(一种微孔金属有机骨架,MOF)粒径为60nm,200-600nm,或800-1000分散在液体聚二甲基硅氧烷(PDMS)。检查的性质包括分散体的物理稳定性,粘度,总CO2吸收,和二氧化碳吸收动力学。不出所料,物理稳定性和粘度均随粒径的增加而降低。出乎意料的是,总重量气体吸收也随颗粒大小而变化,对最大的粒子来说是最大的,我们将其归因于具有较低相对含量的表面结合的FMA配体的较大颗粒。考虑了气体吸收动力学数据的各种模型,特别是吸附反应模型,如伪一级,伪二阶,还有Elovich的模特.与纯PDMS相比,显示了一级动力学,所有PLs最符合Elovich模型,证实它们的摄取机制比简单液体更复杂。吸附扩散模型,特别是韦伯和莫里斯的内部模型和博伊德的模型,也被应用,这揭示了一个三步过程,其中通过表面层的扩散和粒子内扩散的组合是限速的。气体吸收速率遵循PDMS Type III porous liquids (PLs) consist of porous solid particles dispersed in a size-excluded liquid phase and are attracting much attention as novel media for applications such as gas separation. However, the effects of fundamental variables such as particle size on their physical properties are currently largely unknown. Here we study the effects of particle size in a series of porous liquids based on solid Al(OH)(fumarate) (a microporous metal-organic framework, MOF) with particle sizes of 60 nm, 200-600 nm, or 800-1000 dispersed in liquid polydimethylsiloxane (PDMS). Properties examined include physical stability of the dispersion, viscosity, total CO2 uptake, and kinetics of CO2 uptake. As expected, both physical stability and viscosity decreased with increasing particle size. Unexpectedly, total gravimetric gas uptake also varied with particle size, being greatest for the largest particles, which we ascribe to larger particles having a lower relative content of surface-bound FMA ligands. Various models for the gas uptake kinetic data were considered, specifically adsorption reaction models such as pseudo-first-order, pseudo-second-order, and Elovich models. In contrast to pure PDMS, which showed first-order kinetics, all PLs fit best to the Elovich model confirming that their uptake mechanism is more complex than for a simple liquid. Adsorption diffusion models, specifically Weber and Morris\' intraparticle model and Boyd\'s model, were also applied which revealed a three-step process in which a combination of diffusion through a surface layer and intraparticle diffusion were rate-limiting. The rate of gas uptake follows the order PDMS < PL1 < PL2 < PL3, showing that the porous liquids take up gas more rapidly than does PDMS and that this rate increases with particle size. Overall, the study suggests that for high gas uptake and fast uptake kinetics, large particles may be preferred. Also, the fact that large particles resulted in low viscosity may be advantageous in reducing the pumping energy needed in flow separation systems. Therefore, the work suggests that finding ways to stabilize PLs with large particles against phase separation could be advantageous for optimizing the properties of PLs toward applications.
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  • 文章类型: Journal Article
    本文对气态SO2在不同温度条件下在II型多孔液体中的包封进行了理论分子模拟研究。该系统由分散在二氯甲烷中的笼状隐托烷-111分子组成,并使用分子动力学的原子模型进行描述。在整个模拟过程中,气态SO2倾向于几乎完全占据cryptophane-111腔。在300K和283K下进行计算,并获得了在每种情况下发现的不同吸附的一些见解。还研究了不同系统尺寸的模拟。通过在模拟盒中插入SO2气泡,还采用了类似实验的方法。最后,还对cryptophane-111和气态SO2的径向分布函数进行了评估。从获得的结果来看,提到了使用多孔液体对SO2进行可再生分离和存储方法的可行性。
    A theoretical molecular simulation study of the encapsulation of gaseous SO2 at different temperature conditions in a type II porous liquid is presented here. The system is composed of cage cryptophane-111 molecules that are dispersed in dichloromethane, and it is described using an atomistic modelling of molecular dynamics. Gaseous SO2 tended to almost fully occupy cryptophane-111 cavities throughout the simulation. Calculations were performed at 300 K and 283 K, and some insights into the different adsorption found in each case were obtained. Simulations with different system sizes were also studied. An experimental-like approach was also employed by inserting a SO2 bubble in the simulation box. Finally, an evaluation of the radial distribution function of cryptophane-111 and gaseous SO2 was also performed. From the results obtained, the feasibility of a renewable separation and storage method for SO2 using porous liquids is mentioned.
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  • 文章类型: Journal Article
    多孔液体是在各种领域中表现出独特性质的多孔材料。在这里,我们开发了一种通过化学修饰的环糊精液化合成I型多孔液体的方法。利用傅里叶变换红外光谱(FTIR)对环糊精多孔液体进行了表征,NMR,基质辅助激光解吸电离飞行时间质谱(MALDI-TOFMS),圆二色性(CD),和紫外可见光谱。测得的γ-环糊精多孔液体的离子电导率是其反应物的500倍,这被发现是对于I型多孔液体具有如此高的电导率的第一个实例。更重要的是,实验证明γ-环糊精多孔液体对水中嘧啶核苷具有优异的手性识别能力,计算模拟进一步证实了这一点。此外,通过从外消旋核苷和γ-环糊精多孔液体的混合物中方便地提取,提取的核苷的对映体过量高达84.81%。新型环糊精多孔液体的巨大特性可以在许多领域带来机遇,包括手性分离材料的制备,开发新的药物筛选机制,手性响应材料的构建。
    Porous liquids are porous materials that have exhibited unique properties in various fields. Herein, we developed a method to synthesize the type I porous liquids via liquefaction of cyclodextrins by chemical modification. The cyclodextrin porous liquids were characterized by Fourier-transform infrared (FTIR) spectroscopy, NMR, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), circular dichroism (CD), and UV-vis spectroscopy. The measured ionic conductivity of the γ-cyclodextrin porous liquid was 500 times as great as that of its reactants, which was found to be the first instance with such great conductivity for a type I porous liquid. What is more, the γ-cyclodextrin porous liquid had been demonstrated experimentally to have outstanding chiral recognition ability toward pyrimidine nucleosides in water, which was further confirmed by computational simulations. Additionally, enantiomeric excess of the extracted nucleoside was achieved up to 84.81% by convenient extraction from the mixture of racemic nucleosides and γ-cyclodextrin porous liquid. The great features of the novel cyclodextrin porous liquids could bring opportunities in many fields, including the preparation of chiral separation materials, development of new drug screening mechanisms, and construction of chiral response materials.
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  • 文章类型: Journal Article
    II型多孔液体被证明是有希望的多孔材料。然而,多孔宿主的类别非常有限。这里,据报道,多孔主体金属有机多面体(MOP-18)可构建II型多孔液体。将MOP-18溶解在15-冠-5中作为单独的笼(5nm)。分子动力学模拟和实验重量分析CO2溶解度测试均表明,MOP-18在多孔液体中的内腔未被15-crown-5占据,并且可以进入CO2。因此,制备的多孔液体显示出增强的气体溶解度。此外,将制备的多孔液体包封到氧化石墨烯(GO)纳米砂中,以形成GO负载的多孔液体膜(GO-SPLM)。由于MOP-18单元笼在多孔液体中的空腔减少了气体扩散屏障,GO-SPLM显著提高了气体的渗透性。
    Type II porous liquids are demonstrated to be promise porous materials. However, the category of porous hosts is very limited. Here, a porous host metal-organic polyhedra (MOP-18) is reported to construct type II porous liquids. MOP-18 is dissolved into 15-crown-5 as an individual cage (5 nm). Both the molecular dynamics simulations and experimental gravimetric CO2 solubility test indicate that the inner cavity of MOP-18 in porous liquids is unoccupied by 15-crown-5 and is accessible to CO2 . Thus, the prepared porous liquids show enhanced gas solubility. Furthermore, the prepared porous liquid is encapsulated into graphene oxide (GO) nanoslits to form a GO-supported porous liquid membrane (GO-SPLM). Owing to the empty cavity of MOP-18 unit cages in porous liquids that reduces the gas diffusion barrier, GO-SPLM significantly enhances the permeability of gas.
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  • 文章类型: Journal Article
    固体多孔材料,像沸石,由于它们的多孔性,它们已经被广泛地用于各种领域,例如尺寸和形状选择性吸收/分离和催化。然而,很少有液体材料表现出永久的孔隙率。多孔液体是一种结合了流动性和永久孔隙率特性的新型材料。它们在气体分离等许多领域都有潜在的应用,储存和运输。在这里,我们报道了一种基于硅沸石-1制备的新型1型多孔液体。该多孔液体的孔径由正电子湮没寿命光谱(PALS)测定,二氧化碳容量由智能重量分析仪(IGA)测定。这种多孔液体的独特性能可以促进其在气体储存和运输等许多领域的应用。
    Solid porous materials, like zeolites, have been widely used in a variety of fields such as size-and-shape-selective absorption/separation and catalysis because of their porosity. However, there are few liquid materials that exhibit permanent porosity. Porous liquids are a novel material that combine the properties of fluidity and permanent porosity. They have potential applications in many fields such as gas separation, storage and transport. Herein, we report a novel Type 1 porous liquid prepared based on silicalite-1. The pore size of this porous liquid was determined by positron annihilation lifetime spectroscopy (PALS), and the CO2 capacities were determined by the intelligent gravimetric analyzer (IGA). The unique properties of this porous liquid can promote its application in many fields such as gas storage and transport.
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