渗透蒸发

Abstract(#br)Recently much endeavor has been devoted to improving pervaporation performances of polydimethylsiloxane (PDMS) membranes for organic aqueous solutions by doping hydrophobic porous particles. However, the strategy generally promotes water permeation as well, which is contrary to the separation purpose but has not caused researchers' attention.

Abstract(#br)Bio-butanol is an important aspect for development of renewable energy. Currently, it remains challenging for developing highly permeable and selective composite membranes to efficiently recover butanol produced in biomass fermentation process. In this work, we fabricated polydimethylsiloxane (PDMS) into thin and defect-free composite membranes by using porous PVDF as the substrate. The formation of PDMS membrane layer was finely controlled by optimizing the substrate pore size and casting solution viscosity.

Abstract(#br)High separation performance and superior mechanical properties of the membranes are both of critical importance for membrane modules to achieve high efficiency and long-term stability. Herein, a series of mixed matrix membranes (MMMs) with brick-and-mortar architecture are prepared by incorporating two-dimensional zeolitic imidazolate framework-L (ZIF-L) nanosheets into polydimethylsiloxane (PDMS) matrix for separating alcohols (ethanol, n -propanol or n -butanol) from aqueous solution.

摘要\n本研究借助密度泛函理论计算，基于溶液扩散机制，初步构思了一种独特的MOF封端纳米管结构。然后，制备了新型ZIF-8封端埃洛石纳米管( ZHNTs )，并将其嵌入到聚二甲基硅氧烷( PDMS )本体中，实现了正丁醇渗透汽化的混合基质膜( MMMs )。该膜的显著特点是ZHNTs中的HNT管腔( φ25 nm )为首次通过封盖ZIF-8层筛选的渗透剂提供了精致的扩散通道。同时，ZIF-8层在ZHNTs外表面的紧密连接为分子渗透创造了相对连续的途径。正如预期的那样，ZHNTs的嵌入显著提高了膜的分离性能。令人印象深刻的是，在1 wt %正丁醇水溶液的分离中，40℃时，所得膜的分离因子高达61.3 (比PDMS对照膜高58.7 % )，通量可比683 g m-2 h-1 (是PDMS对照膜的2.43倍)。此外，ZHNTs的存在赋予膜良好的界面相容性、力学性能和长期稳定性。本研究可能对合理设计用于发酵液生物燃料回收的高性能MMMs有所启示。

摘要\n亲水金属有机骨架( MOFs )和疏水聚二甲基硅氧烷( PDMS )之间的界面相容性通过表面活性剂和聚合物包裹等超分子修饰而不被有效调和。下面我们报道一种共价交联策略来加强MOFs ~ PDMS界面。三甲氧基硅烷( TMS )修饰锆MOFs ( UiO-66 - NH2 )，可进一步与硅醇终止的PDMS反应，增强UiO-66 ~ PDMS界面相容性。高含量的UiO-66 - TMS (最高可达50 wt % )负载到PDMS中，保持了较好的成膜能力、机械性能和渗透汽化选择性，但与原UiO-66 - NH2相比，即使在较低的负载量( 10 wt % )下，膜的强度和分离性能都有所下降。在保持选择性的前提下，混合基质膜在乙醇-水混合脱水中的通量得到了很大的提高。在40℃下连续2次渗透蒸发，可从稀进料中高效生产浓乙醇(等效通量为2234 g / m2 h，渗透液中乙醇质量分数为53 wt % )，且具有共价增强界面的膜在连续运行100 h时性能稳定。

摘要\n联苯基共价三嗪骨架( CTF )粒子作为一类新型的有机多孔材料，被掺入聚二甲基硅氧烷( PDMS )中，制备了用于正丁醇( n- BtOH )回收的高性能渗透汽化膜。增加CTF的负载量显著提高了膜的通量和分离因子。这是由于CTF的强疏水性、高孔性和介孔结构为n- BtOH提供了高透水性和择优性的通道，重要的是，与其他报道的含常规微孔粒子的PDMS基混合基质膜相比，CTF / PDMS ( CTF / PDMS )膜具有更高的通量和更好的分离因子。提高进料温度和n- BtOH浓度进一步增强了渗透汽化性能。因此，将含12.5 wt % CTF的CTF / PDMS膜与4 wt %的n- BtOH进料液在60℃下操作时，n- BtOH的回收率最高(总渗透通量2816±118 g m-2 h-1，分离因子62.8±1.5，渗透n- BtOH浓度71.5±2.7 wt % )。

Abstract\n\t\t\t\t\n\t\t\t\t\tThe syntheses of siloxane-grafted poly(amide-imide) and polyamide were carried out by a macromonomer method, in order to develop a highly permeable and durable membrane material for pervaporation. A novel compound, 3,5-bis(4-aminophenoxy)benzyloxypropyl-terminated polydimethylsiloxane (\n\t\t\t\t\t\tBAPB-\n\t\t\t\t\t\tPDMS), was synthesized as a macromonomer.

Effect of Concentration Polarization on The Pervaporation of Aqueous Chlorinated-Organic SolutionPolydimethylsiloxane;Concentration Polarization;Pervaporation;Resistance-in-series;Separation Factor;The pervaporation experiments of aqueous solutions of trichloroethylene (TCE) and chlorobenzene (CB) through the silicone rubber (polydimethylsiloxane, PDMS) membrane were carried out and the effect of concentration polarization on the separation characteristics was investigated. The resistance-in-series model was used to explain the boundary layer resistance.

Pervaporation of Butanol from their Aqueous Solution using a PDMS-Zeolite Composite Membranen-Butanol;Pervaporation;PDMS-Zeolite;Zeolite Membrane;Pervaporation is known to be a low energy consumption process since it needs only an electric power to maintain the permeate side in vacuum. Also, the pervaporation is an environmentally clean technology because it does not use the third material such as an entrainer for either an azeotropic distillation or an extractive distillation.

Pervaporative Recovery of Bio-butanol through Dense- and Composite-type PDMS Membranesbio-Butanol;polydimethylsiolxane;pervaporation;composite;membrane;recovery;Bio-butanol recovery by pervaporation was performed with dense and composite polydimethylsiloxane (PDMS) membranes. The pervaporative behavior of the membranes was investigated as a function of operation temperature $(20{\\sim}40^{\\circ}C)$ and membrane thickness $(100{\\sim}1{\\mu}m)$ using a series of aqueous BtOH model solutions $(1{\\sim}5wt%)$.