Advanced Membranes and Porous Materials Center

science and, Saudi Arabia

Advanced Membranes and Porous Materials Center

science and, Saudi Arabia

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Yave W.,Helmholtz Center Geesthacht | Car A.,Helmholtz Center Geesthacht | Wind J.,Max Planck Institute for Polymer Research | Peinemann K.-V.,Helmholtz Center Geesthacht | Peinemann K.-V.,Advanced Membranes and Porous Materials Center
Nanotechnology | Year: 2010

Miniaturization and manipulation of materials at nanometer scale are key challenges in nanoscience and nanotechnology. In membrane science and technology, the fabrication of ultra-thin polymer films (defect-free) on square meter scale with uniform thickness (<100 nm) is crucial. By using a tailor-made polymer and by controlling the nanofabrication conditions, we developed and manufactured defect-free ultra-thin film membranes with unmatched carbon dioxide permeances, i.e. >5 m3 (STP) m-2 h -1 bar-1. The permeances are extremely high, because the membranes are made from a CO2 philic polymer material and they are only a few tens of nanometers thin. Thus, these thin film membranes have potential application in the treatment of large gas streams under low pressure like, e.g., carbon dioxide separation from flue gas. © 2010 IOP Publishing Ltd.


Zhu Y.,Advanced Membranes and Porous Materials Center | He J.,Nanyang Technological University | Shang C.,Fudan University | Miao X.,King Abdullah University of Science and Technology | And 4 more authors.
Journal of the American Chemical Society | Year: 2014

A Boerdijk-Coxeter-Bernal (BCB) helix is made of linearly stacked regular tetrahedra (tetrahelix). As such, it is chiral without nontrivial translational or rotational symmetries. We demonstrate here an example of the chiral BCB structure made of totally symmetrical gold atoms, created in nanowires by direct chemical synthesis. Detailed study by high-resolution electron microscopy illustrates their elegant chiral structure and the unique one-dimensional "pseudo-periodicity". The BCB-type atomic packing mode is proposed to be a result of the competition and compromise between the lattice and surface energy. © 2014 American Chemical Society.


Marques D.S.,King Abdullah University of Science and Technology | Vainio U.,German Electron Synchrotron | Chaparro N.M.,King Abdullah University of Science and Technology | Calo V.M.,King Abdullah University of Science and Technology | And 4 more authors.
Soft Matter | Year: 2013

Membranes with exceptional pore regularity and high porosity were obtained from block copolymer solutions. We demonstrate by small-angle X-ray scattering that the order which gives rise to the pore morphology is already incipient in the casting solution. Hexagonal order was confirmed in PS-b-P4VP 175k-b-65k solutions in DMF/THF/dioxane with concentrations as high as 24 wt%, while lamellar structures were obtained in more concentrated solutions in DMF or DMF/dioxane. The change in order has been understood with the support of dissipative particle dynamic modeling. © 2013 The Royal Society of Chemistry.


Hilke R.,Advanced Membranes and Porous Materials Center | Pradeep N.,Advanced Membranes and Porous Materials Center | Behzad A.R.,Imaging and Characterization Laboratory | Nunes S.P.,King Abdullah University of Science and Technology | Peinemann K.-V.,Advanced Membranes and Porous Materials Center
Journal of Membrane Science | Year: 2014

We manufactured the first time block copolymer dual-layer hollow fiber membranes and dual layer flat sheet membranes manufactured by double solution casting and phase inversion in water. The support porous layer was based on polystyrene and the selective layer with isopores was formed by micelle assembly of polystyrene-. b-poly-4-vinyl pyridine. The dual layers had an excellent interfacial adhesion and pore interconnectivity. The dual membranes showed pH response behavior like single layer block copolymer membranes with a low flux for pH values less than 3, a fast increase between pH4 and pH6 and a constant high flux level for pH values above 7. The dry/wet spinning process was optimized to produce dual layer hollow fiber membranes with polystyrene internal support layer and a shell block copolymer selective layer. © 2014 Elsevier B.V.


Khalilpour R.,University of Sydney | Abbas A.,University of Sydney | Lai Z.,Advanced Membranes and Porous Materials Center | Pinnau I.,Advanced Membranes and Porous Materials Center
Chemical Engineering Research and Design | Year: 2013

This paper analysed the performance of a membrane system over key design/operation parameters. A computation methodology is developed to solve the model of hollow fibre membrane systems for multicomponent gas feeds. The model represented by a nonlinear differential algebraic equation system is solved via a combination of backward differentiation and Gauss-Seidel methods. Natural gas sweetening problem is investigated as a case study. Model parametric analyses of variables, namely feed gas quality, pressure, area, selectivity and permeance, resulted in better understanding of operating and design optima. Particularly, high selectivities and/or permeabilities are shown not to be necessary targets for optimal operation. Rather, a medium selectivity (<60 in the given example) combined with medium permeance (∼300-500×10-10mol/sm2Pa in the given case study) is more advantageous. This model-based membrane systems engineering approach is proposed for the synthesis of efficient and cost-effective multi-stage membrane networks. © 2012 The Institution of Chemical Engineers.


Alshehri A.,Advanced Membranes and Porous Materials Center | Khalilpour R.,University of Sydney | Abbas A.,University of Sydney | Lai Z.,Advanced Membranes and Porous Materials Center
Energy Procedia | Year: 2013

This study proposes a strategy for optimal design of hollow fiber membrane networks for post combustion carbon capture from power plant multicomponent flue gas. A mathematical model describing multicomponent gas permeation through a separation membrane was customized into the flowsheet modeling package ASPEN PLUS. An N-stage membrane network superstructure was defined considering all possible flowsheeting configurations. An optimization formulation was then developed and solved using an objective function that minimizes the costs associated with operating and capital expenses. For a case study of flue gas feed flow rate of 298 m3/s with 13% CO2 and under defined economic parameters, the optimization resulted in the synthesis of a membrane network structure consisting of two stages in series. This optimal design was found while also considering feed and permeate pressures as well as recycle ratios between stages. The cost of carbon capture for this optimal membrane network is estimated to be $28 per tonne of CO2 captured, considering a membrane permeance of 1000 GPU and membrane selectivity of 50. Following this approach, a reduction in capture cost to less than $20 per tonne CO2 captured is possible if membranes with permeance of 2000 GPU and selectivity higher than 70 materialize. © 2013 The Author.


Alezi D.,Advanced Membranes and Porous Materials Center | Belmabkhout Y.,Advanced Membranes and Porous Materials Center | Suyetin M.,Advanced Membranes and Porous Materials Center | Bhatt P.M.,Advanced Membranes and Porous Materials Center | And 7 more authors.
Journal of the American Chemical Society | Year: 2015

The molecular building block approach was employed effectively to construct a series of novel isoreticular, highly porous and stable, aluminum-based metal-organic frameworks with soc topology. From this platform, three compounds were experimentally isolated and fully characterized: namely, the parent Al-soc-MOF-1 and its naphthalene and anthracene analogues. Al-soc-MOF-1 exhibits outstanding gravimetric methane uptake (total and working capacity). It is shown experimentally, for the first time, that the Al-soc-MOF platform can address the challenging Department of Energy dual target of 0.5 g/g (gravimetric) and 264 cm3 (STP)/cm3 (volumetric) methane storage. Furthermore, Al-soc-MOF exhibited the highest total gravimetric and volumetric uptake for carbon dioxide and the utmost total and deliverable uptake for oxygen at relatively high pressures among all microporous MOFs. In order to correlate the MOF pore structure and functionality to the gas storage properties, to better understand the structure-property relationship, we performed a molecular simulation study and evaluated the methane storage performance of the Al-soc-MOF platform using diverse organic linkers. It was found that shortening the parent Al-soc-MOF-1 linker resulted in a noticeable enhancement in the working volumetric capacity at specific temperatures and pressures with amply conserved gravimetric uptake/working capacity. In contrast, further expansion of the organic linker (branches and/or core) led to isostructural Al-soc-MOFs with enhanced gravimetric uptake but noticeably lower volumetric capacity. The collective experimental and simulation studies indicated that the parent Al-soc-MOF-1 exhibits the best compromise between the volumetric and gravimetric total and working uptakes under a wide range of pressure and temperature conditions. © 2015 American Chemical Society.


Khalilpour R.,University of Sydney | Abbas A.,University of Sydney | Lai Z.,Advanced Membranes and Porous Materials Center | Pinnau I.,Advanced Membranes and Porous Materials Center
AIChE Journal | Year: 2012

The modeling and optimal design/operation of gas membranes for postcombustion carbon capture (PCC) is presented. A systematic methodology is presented for analysis of membrane systems considering multicomponent flue gas with CO 2 as target component. Simplifying assumptions is avoided by namely multicomponent flue gas represented by CO 2/N 2 binary mixture or considering the co/countercurrent flow pattern of hollow-fiber membrane system as mixed flow. Optimal regions of flue gas pressures and membrane area were found within which a technoeconomical process system design could be carried out. High selectivity was found to not necessarily have notable impact on PCC membrane performance, rather, a medium selectivity combined with medium or high permeance could be more advantageous. © 2011 American Institute of Chemical Engineers (AIChE).


News Article | February 21, 2017
Site: www.eurekalert.org

Researchers at KAUST have developed a method for fine-scale imaging of metal-organic frameworks (MOFs), three-dimensional structures made up of metal ions connected by organic ligands. MOFs are useful for gas storage and separation because they can be designed to have precise pore sizes of molecular dimensions and large void spaces (porosity) within their frameworks. Typically, high-resolution transmission electron microscopy (HRTEM) is used to visualize structures with atomic resolution; however, this method is unsuitable for observing MOFs because the electron beams destroy their structures. "To thoroughly understand the performance of metal-organic frameworks in various applications, we need to know their structures at the atomic level because their macroscopic behavior is determined by their microscopic structure," explained KAUST Associate Professor of Chemical Science Yu Han. By visualizing these structures, researchers can uncover important clues about how these materials self-assemble to create their trademark pores. Several members of the University's Advanced Membranes and Porous Materials Center, including Han's research scientist and first author of the paper, Yihan Zhu, Associate Professor of Chemical and Biological Engineering Zhiping Lai and Professor of Chemical and Biological Engineering and Director of the Center Ingo Pinnau, joined forces with the University's Imaging and Characterization Core Lab and with colleagues from Gatan, Lawrence Berkeley National Laboratory and others in China. Their collaboration resulted in an adaptation of HRTEM using state-of-the-art direct-detection electron-counting cameras. The high sensitivity of these detectors enabled them to acquire images with an electron dose low enough that it does not damage the structure of MOFs, allowing the group to produce high-resolution images of their atomic structures. The team applied their method to ZIF-8, a MOF comprising zinc ions connected by organic 2-methylimidazole linkers. They were able to image its structure with a resolution of 0.21 nanometers (one nanometer is one billionth of a meter), a resolution high enough to image the individual columns of zinc atoms and organic linkers. This helped the researchers to reveal the surface and interfacial structures of ZIF-8 crystals. "The results unraveled that porosity generated at the interfaces of ZIF-8 crystals is different from the intrinsic porosity of ZIF-8, which influences how gas molecules transport in ZIF-8 crystals," explained Han.


Researchers at KAUST have developed a method for fine-scale imaging of metal-organic frameworks (MOFs), three-dimensional structures made up of metal ions connected by organic ligands. MOFs are useful for gas storage and separation because they can be designed to have precise pore sizes of molecular dimensions and large void spaces (porosity) within their frameworks. Typically, high-resolution transmission electron microscopy (HRTEM) is used to visualize structures with atomic resolution; however, this method is unsuitable for observing MOFs because the electron beams destroy their structures. "To thoroughly understand the performance of metal-organic frameworks in various applications, we need to know their structures at the atomic level because their macroscopic behavior is determined by their microscopic structure," explained KAUST Associate Professor of Chemical Science Yu Han. By visualizing these structures, researchers can uncover important clues about how these materials self-assemble to create their trademark pores. Several members of the University's Advanced Membranes and Porous Materials Center, including Han's research scientist and first author of the paper, Yihan Zhu, Associate Professor of Chemical and Biological Engineering Zhiping Lai and Professor of Chemical and Biological Engineering and Director of the Center Ingo Pinnau, joined forces with the University's Imaging and Characterization Core Lab and with colleagues from Gatan, Lawrence Berkeley National Laboratory and others in China. Their collaboration resulted in an adaptation of HRTEM using state-of-the-art direct-detection electron-counting cameras1. The high sensitivity of these detectors enabled them to acquire images with an electron dose low enough that it does not damage the structure of MOFs, allowing the group to produce high-resolution images of their atomic structures. The team applied their method to ZIF-8, a MOF comprising zinc ions connected by organic 2-methylimidazole linkers. They were able to image its structure with a resolution of 0.21 nanometers (one nanometer is one billionth of a meter), a resolution high enough to image the individual columns of zinc atoms and organic linkers. This helped the researchers to reveal the surface and interfacial structures of ZIF-8 crystals. "The results unraveled that porosity generated at the interfaces of ZIF-8 crystals is different from the intrinsic porosity of ZIF-8, which influences how gas molecules transport in ZIF-8 crystals," explained Han. Explore further: Tweaking the structure of metal-organic frameworks could transform the capacity to use methane as a fuel More information: Unravelling surface and interfacial structures of a metal-organic framework by transmission electron microscopy. Nature Materials, advance online publication, 20 February 2017. dx.doi.org/10.1038/nmat4852

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