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Zeolite Membrane

Arturo Barjola, Jorge Escorihuela, Andreu Andrio, Enrique Giménez, Vicente Compañ
The zeolitic imidazolate frameworks (ZIFs) ZIF-8, ZIF-67, and a Zn/Co bimetallic mixture (ZMix) were synthesized and used as fillers in the preparation of composite sulfonated poly(ether ether ketone) (SPEEK) membranes. The presence of the ZIFs in the polymeric matrix enhanced proton transport relative to that observed for SPEEK or ZIFs alone. The real and imaginary parts of the complex conductivity were obtained by electrochemical impedance spectroscopy (EIS), and the temperature and frequency dependence of the real part of the conductivity were analyzed...
December 13, 2018: Nanomaterials
Derrick S Dlamini, Bhekie B Mamba, Jianxin Li
This review looks into the efforts made towards commercializing nano-enable flat sheet membranes as well as the challenges that need to be overcome. There is a question mark on the argument that the nano-pores of the fillers play a significant role in the performance of the membrane. Non porous nanomaterials have been reported to cause in increase in water flux, yet there are still articles that credit the nano-pores of the nanomaterials for improved membrane performance. There are two points that are important to highlight: (1) the nanoparticles, e...
November 29, 2018: Science of the Total Environment
Palmira Tavolaro, Silvia Catalano, Adalgisa Tavolaro
This paper deals with the design and manufacture of pure and hybrid synthetic (Mixed Matrix Membranes, MMMs) zeolite scaffolds (containing various amount of zeolite crystals dispersed in a polymeric matrix) to obtain new biomaterials. These scaffolds can potentially be used in the field of translational medicine to obtain innovative results to address tumorigenesis mechanisms with the promotion of an effort to deal with technical methods and information. Since olive oil has beneficial effects in healthy human cells and slows down and/or inhibits cell growth, the aim of this work was to monitor the protective and beneficial antitumor effects of olive oil in a new solid formulation (Spread Bio-Oil) on cancer cell cultured on zeolite scaffolds...
December 4, 2018: Food and Chemical Toxicology
Zishu Cao, Shixuan Zeng, Zhi Xu, Antonios Arvanitis, Shaowei Yang, Xuehong Gu, Junhang Dong
The tremendous potential of zeolite membranes for efficient molecular separation via size-exclusion effects is highly desired by the energy and chemical industries, but its practical realization has been hindered by nonselective permeation through intercrystalline spaces and high resistance to intracrystalline diffusion in the conventional zeolite membranes of randomly oriented polycrystalline structures. Here, we report the synthesis of ZSM-5 zeolite nanosheets with very large aspect ratios and nanometer-scale thickness in the preferred straight channel direction...
November 2018: Science Advances
Qisong Xu, Kang Zhang, Jianwen Jiang
The need to understand and describe permeation through membranes has driven the development of many well-established transport models. The modelling parameters such as solubility, diffusivity and permeability represent the intrinsic nature of molecular interactions between membrane and permeants. In this study, we report a simulation and analysis methodology for liquid permeation. Based on a single simulation of liquid sorption process into a membrane, the solubility and diffusivity are estimated simultaneously, then the permeability is predicted by the solution-diffusion model...
November 21, 2018: Journal of Physical Chemistry. B
Zahir Razzaz, Denis Rodrigue
In this work, hollow fiber porous nanocomposite membranes were successfully prepared by the incorporation of a porous nanoparticle (zeolite 5A) into a blend of linear low-density polyethylene (LLDPE)/low-density polyethylene (LDPE) combined with azodicarbonamide as a chemical blowing agent (CBA). Processing was performed via continuous extrusion using a twin-screw extruder coupled with a calendaring system. The process was firstly optimized in terms of extrusion and post-extrusion conditions, as well as formulation to obtain a good cellular structure (uniform cell size distribution and high cell density)...
November 17, 2018: Materials
Stefan Beisl, Sílvia Monteiro, Ricardo Santos, Ana Sofia Figueiredo, María Guadalupe Sánchez-Loredo, Maria Amélia Lemos, Francisco Lemos, Miguel Minhalma, Maria Norberta de Pinho
The present work addresses the synthesis of nanofiltration composite membranes with bactericide properties. The cellulose acetate based membranes with polyvinylpyrrolidone coated silver nanoparticles, silver ion-exchanged β-zeolite and β-zeolite are casted by the phase inversion technique and subjected to an annealing post-treatment. They are characterized in terms of the nanofiltration permeation performance and antibacterial properties. The incorporation of silver nanoparticles produces a threefold increase in the membrane hydraulic permeability when compared to the silver-free membranes and the incorporation of silver ion loaded zeolite resulted in a 56...
November 5, 2018: Water Research
Sheng Zhou, Yanying Wei, Libo Li, Yifan Duan, Qianqian Hou, Lili Zhang, Liang-Xin Ding, Jian Xue, Haihui Wang, Jürgen Caro
Metal-organic framework (MOF) membranes show great promise for propene/propane separation, yet a sharp molecular sieving has not been achieved due to their inherent linker mobility. Here, zeolitic imidazolate framework ZIF-8-type membranes with suppressed linker mobility are prepared by a fast current-driven synthesis (FCDS) strategy within 20 min, showing sharpened molecular sieving for propene/propane separation with a separation factor above 300. During membrane synthesis, the direct current promotes the metal ions and ligands to assemble into inborn-distorted and stiffer frameworks with ZIF-8_Cm (a newly discovered polymorph of ZIF-8) accounting for 60 to 70% of the membrane composition...
October 2018: Science Advances
Fereshteh Rashidi, Johannes Leisen, Seok-Jhin Kim, Ali A Rownaghi, Christopher W Jones, Sankar Nair
New membrane-based molecular separation processes are an essential part of the strategy for sustainable chemical production. A large literature on "hybrid" or "mixed-matrix" membranes exists, in which nanoparticles of a higher-performance porous material are dispersed in a polymeric matrix to boost performance. We demonstrate that the hybrid membrane concept can be redefined to achieve much higher performance if the membrane matrix and the dispersed phase are both nanoporous crystalline materials, with no polymeric phase...
November 6, 2018: Angewandte Chemie
Jun Yong Chan, Huacheng Zhang, Yada Nolvachai, Yaoxin Hu, Haijin Zhu, Maria Forsyth, Qinfen Gu, David Hoke, Xiwang Zhang, Philip Marriot, Huanting Wang
Homochiral metal organic framework (MOF) has gained much attention owing to its excellent chiral properties for chiral separation. However, the fabrication of high-quality homochiral MOF membranes remains a challenge due to the difficulty in controlling growth of MOF membranes with chiral functionalities. Herein we report a homochiral zeolitic imidazolate framework-8 (ZIF-8) membrane for efficient chiral separation. The membrane is synthesized by incorporating a natural amino acid, L-histidine (L-His), into ZIF-8's framework...
October 29, 2018: Angewandte Chemie
Michael Z Hu, Chaiwat Engtrakul, Brian L Bischoff, Mi Lu, Mussie Alemseghed
Surface wettability-tailored porous ceramic/metallic membranes (in the tubular and planar disc form) were prepared and studied for both vapor-phase separation and liquid pervaporative separations of water-ethanol mixtures. Superhydrophobic nanoceramic membranes demonstrated more selective permeation of ethanol (relative to water) by cross-flow pervaporation of liquid ethanol⁻water mixture (10 wt % ethanol feed at 80 °C). In addition, both superhydrophilic and superhydrophobic membranes were tested for the vapor-phase separations of water⁻ethanol mixtures...
October 12, 2018: Membranes
Sun-Jie Xu, Qian Shen, Gui-E Chen, Zhen-Liang Xu
Organic solvent nanofiltration (OSN) membranes are always troubled by the "trade-off" effect between solvent flux and solute rejection. Hence, a rapid, convenient, and effective way to synthesize novel β-cyclodextrin-enhanced zeolite imidazole framework-8 (β-CD@ZIF-8) nanoparticles was first proposed and the nanoparticles were doped into both selective layer and poly( m -phenylene isophthalamide) support for fabricating thin-film nanocomposite membranes. Transmission/scanning electron microscopy images and X-ray photoelectron spectroscopy results demonstrate the successful synthesis of β-CD@ZIF-8...
September 30, 2018: ACS Omega
Hasan Irvani, Mojtaba Nakhaei Pour, Ali Vahidi, Somayeh Arezoomandan, Hosein Shojaee-Farah Abady
Toluene is a colorless and flammab1le liquid with the same solubilizing capacity as benzene that is in many cases used as an alternative to benzene, because of the uncertainty of being carcinogens. Workers can be exposed to toluene by breathing the chemical. To avoid inhalation and dermal effects caused by exposure to toluene, solutions such as adsorption, thermal oxidation, membrane separation and photocatalytic processes are applied. In this study, removal of toluene vapors with modified natural zeolite and titanium dioxide nanoparticles was discussed...
July 2018: Medical Gas Research
Changlong Zou, Li-Chiang Lin
Molecular dynamics simulations are employed to demonstrate the potential of zeolite nanosheets as pervaporation membranes for ethanol extraction. Our results show that zeolite nanosheets can provide orders of magnitude higher fluxes compared to currently available membranes and achieve outstanding separation factors. The dominant role of membrane surfaces in determining the separation performance is also identified and explored at an atomic level. Developing nanosheet membranes with hydrophobic surfaces and/or with a minimal surface silanol density represents the keys to enable highly selective separation processes...
November 22, 2018: Chemical Communications: Chem Comm
Ravi C Dutta, Suresh K Bhatia
We use atomistic simulations of CH4 , H2 and CO2 transport to elucidate the effect of internal interfacial barriers on gas transport within nanoscale zeolite crystals of different morphology; such barriers are shown here to have critical significance for the performance of ultrathin membranes and nanoscale mixed matrix composite membranes for gas separation. These interfacial resistances are seen to be confined to a narrow region within the zeolite, adjacent to the phase boundary, and are distinct from the external fluid phase resistance...
November 7, 2018: Physical Chemistry Chemical Physics: PCCP
Paul J Dauenhauer, Omar A Abdelrahman
Confinement of hydrocarbons in nanoscale pockets and pores provides tunable capability for controlling molecules in catalysts, sorbents, and membranes for reaction and separation applications. While computation of the enthalpic interactions of hydrocarbons in confined spaces has improved, understanding and predicting the entropy of confined molecules remains a challenge. Here we show, using a set of nine aluminosilicate zeolite frameworks with broad variation in pore and cavity structure, that the entropy of adsorption can be predicted as a linear combination of rotational and translational entropy...
September 26, 2018: ACS Central Science
Jorge Escorihuela, Óscar Sahuquillo, Abel García-Bernabé, Enrique Giménez, Vicente Compañ
The preparation and characterization of composite polybenzimidazole (PBI) membranes containing zeolitic imidazolate framework 8 (ZIF-8) and zeolitic imidazolate framework 67 (ZIF-67) is reported. The phosphoric acid doped composite membranes display proton conductivity values that increase with increasing temperatures, maintaining their conductivity under anhydrous conditions. The addition of ZIF to the polymeric matrix enhances proton transport relative to the values observed for PBI and ZIFs alone. For example, the proton conductivity of PBI@ZIF-8 reaches 3...
September 29, 2018: Nanomaterials
Abdelaziz Elgamouz, Najib Tijani
The data presented in this article are generated as part of the research article entitled "from a naturally occurring material (clay mineral) to the production of porous ceramic membranes" (Elgamouz and Tijani, 2018) [1]. This article describe how clays as very abundant versatile materials that have many properties not available in pure materials namely, silica, alumina and zirconia can be used for the preparation of ceramic membranes (Karaborni et al., 1996; Oun et al., 2017; Hollanders et al., 2016; de Oliveira Henriques et al...
August 2018: Data in Brief
Xiaotong Zhang, Ying Yan
Catalytic combustion of isopropanol in the structured fixed-bed reactor was investigated over Co-ZSM-5 zeolite membrane catalysts. Firstly, ZSM-5 zeolite membrane catalysts with different Si/Al ratios were coated onto the surface of stainless steel fibres via secondary growth method and wet lay-up paper-making method. Then, cobalt oxides were loaded onto the zeolite membranes by impregnation method. The performance of catalytic combustion of isopropanol was conducted over the prepared zeolite membrane catalysts, and the experimental results showed that the catalyst with infinite Si/Al ratio has the highest catalytic activity for the combustion with the lowest T 90 of isopropanol (285°C)...
August 2018: Royal Society Open Science
Gokay Avci, Sadiye Velioglu, Seda Keskin
Metal organic frameworks (MOFs) have emerged as great adsorbent and membrane candidates for separation of CO2 /H2 mixtures. The main challenge is the existence of thousands of MOFs, which requires computational screening methods to identify the best materials prior to experimental efforts. In this study, we performed high-throughput computational screening of MOFs to examine their adsorbent and membrane performances for CO2 /H2 separation. Grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations were used to compute various adsorbent and membrane performance metrics of 3857 MOFs...
October 3, 2018: ACS Applied Materials & Interfaces
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