CO2 Adsorption in Metal-Organic Framework Mg-MOF-74
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MEMS Technology for Physiologically Integrated Devices
A BioMEMS Review: MEMS Technology for Physiologically Integrated Devices AMY C. RICHARDS GRAYSON, REBECCA S. SHAWGO, AUDREY M. JOHNSON, NOLAN T. FLYNN, YAWEN LI, MICHAEL J. CIMA, AND ROBERT LANGER Invited Paper MEMS devices are manufactured using similar microfabrica- I. INTRODUCTION tion techniques as those used to create integrated circuits. They often, however, have moving components that allow physical Microelectromechanical systems (MEMS) devices are or analytical functions to be performed by the device. Although manufactured using similar microfabrication techniques as MEMS can be aseptically fabricated and hermetically sealed, those used to create integrated circuits. They often have biocompatibility of the component materials is a key issue for moving components that allow a physical or analytical MEMS used in vivo. Interest in MEMS for biological applications function to be performed by the device in addition to (BioMEMS) is growing rapidly, with opportunities in areas such as biosensors, pacemakers, immunoisolation capsules, and drug their electrical functions. Microfabrication of silicon-based delivery. The key to many of these applications lies in the lever- structures is usually achieved by repeating sequences of aging of features unique to MEMS (for example, analyte sensitivity, photolithography, etching, and deposition steps in order to electrical responsiveness, temporal control, and feature sizes produce the desired configuration of features, such as traces similar to cells and organelles) for maximum impact. In this paper, (thin metal wires), vias (interlayer connections), reservoirs, we focus on how the biological integration of MEMS and other valves, or membranes, in a layer-by-layer fashion. The implantable devices can be improved through the application of microfabrication technology and concepts. -
A Density Functional Theory Study of Hydrogen Adsorption in MOF-5
17974 J. Phys. Chem. B 2005, 109, 17974-17983 A Density Functional Theory Study of Hydrogen Adsorption in MOF-5 Tim Mueller and Gerbrand Ceder* Department of Materials Science and Engineering, Massachusetts Institute of Technology, Building 13-5056, 77 Massachusetts AVenue, Cambridge, Massachusetts 02139 ReceiVed: March 8, 2005; In Final Form: August 3, 2005 Ab initio molecular dynamics in the generalized gradient approximation to density functional theory and ground-state relaxations are used to study the interaction between molecular hydrogen and the metal-organic framework with formula unit Zn4O(O2C-C6H4-CO2)3. Five symmetrically unique adsorption sites are identified, and calculations indicate that the sites with the strongest interaction with hydrogen are located near the Zn4O clusters. Twenty total adsorption sites are found around each Zn4O cluster, but after 16 of these are populated, the interaction energy at the remaining four sites falls off significantly. The adsorption of hydrogen on the pore walls creates an attractive potential well for hydrogen in the center of the pore. The effect of the framework on the physical structure and electronic structure of the organic linker is calculated, suggesting ways by which the interaction between the framework and hydrogen could be modified. Introduction ogies can be synthesized using a variety of organic linkers, One of the major obstacles to the widespread adoption of providing the ability to tailor the nature and size of the pores. hydrogen as a fuel is the lack of a way to store hydrogen with Several frameworks have been experimentally investigated for sufficient gravimetric and volumetric densities to be economi- their abilities to store hydrogen, but to date none are able to do cally practical. -
Surface Science 675 (2018) 26–35
Surface Science 675 (2018) 26–35 Contents lists available at ScienceDirect Surface Science journal homepage: www.elsevier.com/locate/susc Molecular and dissociative adsorption of DMMP, Sarin and Soman on dry T and wet TiO2(110) using density functional theory ⁎ Yenny Cardona Quintero, Ramanathan Nagarajan Natick Soldier Research, Development & Engineering Center, 15 General Greene Avenue, Natick, MA 01760, United States ARTICLE INFO ABSTRACT Keywords: Titania, among the metal oxides, has shown promising characteristics for the adsorption and decontamination of Adsorption of nerve agents on TiO2 chemical warfare nerve agents, due to its high stability and rapid decomposition rates. In this study, the ad- Molecular and dissociative adsorption sorption energy and geometry of the nerve agents Sarin and Soman, and their simulant dimethyl methyl Dry and hydrated TiO2 phosphonate (DMMP) on TiO2 rutile (110) surface were calculated using density functional theory. The mole- Slab model of TiO 2 cular and dissociative adsorption of the agents and simulant on dry as well as wet metal oxide surfaces were DFT calculations of adsorption energy considered. For the wet system, computations were done for the cases of both molecularly adsorbed water Nerve agent dissociation mechanisms Nerve agent and simulant comparison (hydrated conformation) and dissociatively adsorbed water (hydroxylated conformation). DFT calculations show that dissociative adsorption of the agents and simulant is preferred over molecular adsorption for both dry and wet TiO2. The dissociative adsorption on hydrated TiO2 shows higher stability among the different configura- tions considered. The dissociative structure of DMMP on hydrated TiO2 (the most stable one) was identified as the dissociation of a methyl group and its adsorption on the TiO2 surface. -
Study of Gases Permeation in Necklace-Shaped Dimethylsiloxane Polymers Bearing POSS Cages
Article Study of Gases Permeation in Necklace-Shaped Dimethylsiloxane Polymers Bearing POSS Cages Roman Selyanchyn 1,*, Shigenori Fujikawa 1,2,3,4, Naohiro Katsuta 5, Kazuya Suwa 6 and Masashi Kunitake 5,* 1 WPI International Institute for Carbon-Neutral Energy Research (WPI-I2CNER) Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan; [email protected] 2 NanoMembrane Technologies Inc., 4-1, Kyudai-Shimachi, Nishi-ku, Fukuoka 819-0388, Japan 3 Center for Molecular Systems (CMS), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan 4 Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, 4259 Nagatsutacho, Midori-ku, Yokohama 226-8503, Japan 5 Faculty of Advanced Science and Technology, Kumamoto University,2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan; [email protected] 6 JNC Petrochemical Corporation, Ichihara Research Center; 5-1 Goikagan, Ichihara, Chiba 290-8551, Japan; [email protected] * Correspondence: [email protected] (R.S.); [email protected] (M.K.); Tel.: +81-92-802-6877 (R.S.); +81-96-342-3673 (M.K.) Received: 26 February 2019; Accepted: 11 April 2019; Published: 16 April 2019 Abstract: The transport of small gases (H2, CO2, N2, O2) through a series of novel membranes based on necklace-shaped inorganic polymers (DMS@POSS), in which a polyhedral oligomeric silsesquioxane (POSS) cage unit and soft chains of oligo-dimethyl siloxane (DMS) were alternately connected, was investigated. The influence of the DMS chain length and crosslinking density of the DMS@POSS on membrane properties were studied. -
ADSORPTION KINETICS of N2O on NATURAL ZEOLITES Rosario
Rev. Int. Contam. Ambie. 32 (2) 237-242, 2016 DOI: 10.20937/RICA.2016.32.02.09 ADSORPTION KINETICS OF N2O ON NATURAL ZEOLITES Rosario HERNÁNDEZ HUESCA1, Jesús PÉREZ ARCOS1, Diana VARGAS HERNÁNDEZ1,2* and María Ana PÉREZ CRUZ1 1 Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, 18 Sur y Avenida San Claudio, Edificio 105I-103, Ciudad Universitaria, Puebla, México, C.P. 72570 2 Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora. Calle Rosales y Bulevar Luis Encinas S/N, Hermosillo, Sonora, México, C.P. 83000 * Autor para correspondencia: [email protected] (Received March 2015; accepted October 2015) Key words: adsorption rate, erionite, mordenite, clinoptilolite ABSTRACT The adsorption kinetics of pure N2O on natural zeolites of the erionite (ZAPS), morde- nite (ZNT), and clinoptilolite (ZSL) types has been measured in the temperature range of 0-100 ºC using a glass, high-vacuum volumetric system. The adsorption capacities of N2O on the ZNT and ZSL samples were lower than that on ZAPS. This result can be due to the limiting volume of the micropores of these zeolites and to the quantity of cations available per unit mass of the dehydrated zeolites (cationic density). It was found that the adsorbed amount and the adsorption rate diminish with increasing tem- perature. This behavior allows us to deduce that the adsorption process of N2O is not of the activated type and that it is not influenced by kinetic effects. It was established that the adsorption of N2O on ZAPS can be effected most efficiently at ambient tem- perature, whereas the use of ZSL could be recommended at 100 ºC. -
Adsorption and Desorption Performance and Mechanism Of
molecules Article Adsorption and Desorption Performance and Mechanism of Tetracycline Hydrochloride by Activated Carbon-Based Adsorbents Derived from Sugar Cane Bagasse Activated with ZnCl2 Yixin Cai 1,2, Liming Liu 1,2, Huafeng Tian 1,*, Zhennai Yang 1,* and Xiaogang Luo 1,2,3,* 1 Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology & Business University (BTBU), Beijing 100048, China; [email protected] (Y.C.); [email protected] (L.L.) 2 School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, LiuFang Campus, No.206, Guanggu 1st road, Donghu New & High Technology Development Zone, Wuhan 430205, Hubei Province, China 3 School of Materials Science and Engineering, Zhengzhou University, No.100 Science Avenue, Zhengzhou 450001, Henan Province, China * Correspondence: [email protected] (H.T.); [email protected] (Z.Y.); [email protected] or [email protected] (X.L.); Tel.: +86-139-8627-0668 (X.L.) Received: 4 November 2019; Accepted: 9 December 2019; Published: 11 December 2019 Abstract: Adsorption and desorption behaviors of tetracycline hydrochloride by activated carbon-based adsorbents derived from sugar cane bagasse modified with ZnCl2 were investigated. The activated carbon was tested by SEM, EDX, BET, XRD, FTIR, and XPS. This activated carbon 2 1 exhibited a high BET surface area of 831 m g− with the average pore diameter and pore volume 3 1 reaching 2.52 nm and 0.45 m g− , respectively. The batch experimental results can be described by Freundlich equation, pseudo-second-order kinetics, and the intraparticle diffusion model, 1 while the maximum adsorption capacity reached 239.6 mg g− under 318 K. -
Molecular Valves for Controlling Gas Phase Transport Made from Discrete Ångström-Sized Pores in Graphene
Molecular valves for controlling gas phase transport made from discrete ångström-sized pores in graphene The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Wang, Luda, Lee W. Drahushuk, Lauren Cantley, Steven P. Koenig, Xinghui Liu, John Pellegrino, Michael S. Strano, and J. Scott Bunch. “Molecular Valves for Controlling Gas Phase Transport Made from Discrete ångström-Sized Pores in Graphene.” Nature Nanotechnology 10, no. 9 (August 3, 2015): 785–90. As Published http://dx.doi.org/10.1038/nnano.2015.158 Publisher Nature Publishing Group Version Original manuscript Citable link http://hdl.handle.net/1721.1/101263 Terms of Use Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Molecular Valves for Controlling Gas Phase Transport Made from Discrete Angstrom-Sized Pores in Graphene Luda Wang1,7, Lee W. Drahushuk2, Lauren Cantley3, Steven P. Koenig4,5, Xinghui Liu1, John Pellegrino1, Michael S. Strano2, and J. Scott Bunch3,6* 1 University of Colorado, Department of Mechanical Engineering, Boulder, CO 80309 USA 2 Massachusetts Institute of Technology, Department of Chemical Engineering, Cambridge, MA 02139 USA 3Boston University, Department of Mechanical Engineering, Boston, MA 02215 USA 4 National University of Singapore, Department of Physics, 117542 Singapore 5National University of Singapore, Center for Advance 2D Materials and Graphene Research Centre, 117546 Singapore 6Boston University, Division of Materials Science and Engineering, Brookline, MA 02446 USA 7 Massachusetts Institute of Technology, Department of Mechanical Engineering, Cambridge, MA 02139 USA (current address) *e-mail: [email protected] An ability to precisely regulate the quantity and location of molecular flux is of value in applications such as nanoscale 3D printing, catalysis, and sensor design1-4. -
High Purity/Recovery Separation of Propylene from Propyne Using Anion Pillared Metal-Organic Framework: Application of Vacuum Swing Adsorption (VSA)
energies Article High Purity/Recovery Separation of Propylene from Propyne Using Anion Pillared Metal-Organic Framework: Application of Vacuum Swing Adsorption (VSA) Majeda Khraisheh 1, Fares AlMomani 1,* and Gavin Walker 2 1 Department of Chemical Engineering, College of Engineering, Qatar University, Doha P.O. Box 2713, Qatar; [email protected] 2 Department of Chemical Sciences, SSPC, Bernal Institute, University of Limerick, V94 T9PX Limerick, Ireland; [email protected] * Correspondence: [email protected]; Tel.: +974-4403-4140 Abstract: Propylene is one of the world’s most important basic olefin raw material used in the produc- tion of a vast array of polymers and other chemicals. The need for high purity grade of propylene is essential and traditionally achieved by the very energy-intensive cryogenic separation. In this study, 2− a pillared inorganic anion SIF6 was used as a highly selective C3H4 due to the square grid pyrazine- based structure. Single gas adsorption revealed a very high C3H4 uptake value (3.32, 3.12, 2.97 and 2.43 mmol·g−1 at 300, 320, 340 and 360 K, respectively). The values for propylene for the same tempera- tures were 2.73, 2.64, 2.31 and 1.84 mmol·g−1, respectively. Experimental results were obtained for the two gases fitted using Langmuir and Toth models. The former had a varied degree of representation of the system with a better presentation of the adsorption of the propylene compared to the propyne system. The Toth model regression offered a better fit of the experimental data over the entire range of pressures. -
Nanoparticle Size Effect on Water Vapour Adsorption by Hydroxyapatite
nanomaterials Article Nanoparticle Size Effect on Water Vapour Adsorption by Hydroxyapatite Urszula Szałaj 1,2,*, Anna Swiderska-´ Sroda´ 1, Agnieszka Chodara 1,2, Stanisław Gierlotka 1 and Witold Łojkowski 1 1 Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland 2 Faculty of Materials Engineering, Warsaw University of Technology, Wołoska 41, 02-507 Warsaw, Poland * Correspondence: [email protected]; Tel.: +48-22-876-04-31 Received: 12 June 2019; Accepted: 10 July 2019; Published: 12 July 2019 Abstract: Handling and properties of nanoparticles strongly depend on processes that take place on their surface. Specific surface area and adsorption capacity strongly increase as the nanoparticle size decreases. A crucial factor is adsorption of water from ambient atmosphere. Considering the ever-growing number of hydroxyapatite nanoparticles applications, we decided to investigate how the size of nanoparticles and the changes in relative air humidity affect adsorption of water on their surface. Hydroxyapatite nanoparticles of two sizes: 10 and 40 nm, were tested. It was found that the nanoparticle size has a strong effect on the kinetics and efficiency of water adsorption. For the same value of water activity, the quantity of water adsorbed on the surface of 10 nm nano-hydroxyapatite was five times greater than that adsorbed on the 40 nm. Based on the adsorption isotherm fitting method, it was found that a multilayer physical adsorption mechanism was active. The number of adsorbed water layers at constant humidity strongly depends on particles size and reaches even 23 layers for the 10 nm particles. The amount of water adsorbed on these particles was surprisingly high, comparable to the amount of water absorbed by the commonly used moisture-sorbent silica gel. -
Theoretical and Experimental Insights Into the Mechanism for Gas Separation Through Nanochannels in 2D Laminar Mxene Membranes
processes Article Theoretical and Experimental Insights into the Mechanism for Gas Separation through Nanochannels in 2D Laminar MXene Membranes Yun Jin 1, Yiyi Fan 1, Xiuxia Meng 1, Weimin Zhang 1,*, Bo Meng 1, Naitao Yang 1,* and Shaomin Liu 2,* 1 School of Chemical Engineering, Shandong University of Technology, Zibo 255049, China; [email protected] (Y.J.); [email protected] (Y.F.); [email protected] (X.M.); [email protected] (B.M.) 2 Department of Chemical Engineering, Curtin University, Perth 6102, Australia * Correspondence: [email protected] (W.Z.); [email protected] (N.Y.); [email protected] (S.L.) Received: 4 September 2019; Accepted: 10 October 2019; Published: 15 October 2019 Abstract: Clarifying the mechanism for the gas transportation in the emerging 2D materials-based membranes plays an important role on the design and performance optimization. In this work, the corresponding studies were conducted experimentally and theoretically. To this end, we measured the gas permeances of hydrogen and nitrogen from their mixture through the supported MXene lamellar membrane. Knudsen diffusion and molecular sieving through straight and tortuous nanochannels were proposed to elucidate the gas transport mechanism. The average pore diameter of 5.05 Å in straight nanochannels was calculated by linear regression in the Knudsen diffusion model. 1 The activation energy for H2 transport in molecular sieving model was calculated to be 20.54 kJ mol− . From the model, we can predict that the gas permeance of hydrogen (with smaller kinetic diameter) is contributed from both Knudsen diffusion and molecular sieving mechanism, but the permeance of larger molecular gases like nitrogen is sourced from Knudsen diffusion. -
Analytical Prediction of Gas Permeation Through Graphene Nanopores of Varying Sizes: Understanding Transitions Across Multiple Transport Regimes
Analytical Prediction of Gas Permeation through Graphene Nanopores of Varying Sizes: Understanding Transitions across Multiple Transport Regimes Zhe Yuan†, Rahul Prasanna Misra†, Ananth Govind Rajan‡, Michael S. Strano†, and Daniel Blankschtein†∗ † Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA ‡ Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544, USA *E-mail: [email protected] 1 Abstract Nanoporous graphene is a promising candidate material for gas separation membranes, due to its atomic thickness and low cross-membrane transport resistance. The mechanisms of gas permeation through graphene nanopores, in both the large and small pore size limits, have been reported in the literature. However, mechanistic insights into the crossover from the small pore size limit to the large pore size limit are still lacking. In this study, we develop a comprehensive theoretical framework to predict gas permeance through graphene nanopores having a wide range of diameters using analytical equations. We formulate the transport kinetics associated with the direct impingement from the bulk and with the surface diffusion from the adsorption layer on graphene, and then combine them to predict the overall gas permeation rate using a reaction network model. We also utilize molecular dynamics simulations to validate and calibrate our theoretical model. We show that the rates of both the direct impingement and the surface diffusion pathways need to be corrected using different multiplicative factors, which are functions of temperature, gas kinetic diameter, and pore diameter. Further, we find a minor spillover pathway that originates from the surface adsorption layer, but is not included in our theoretical model. -
Separation of Xylene Isomers Through Multiple Metal Site Interactions in Metal−Organic Frameworks † ○ † ○ † # † † Miguel I
Article Cite This: J. Am. Chem. Soc. 2018, 140, 3412−3422 pubs.acs.org/JACS Separation of Xylene Isomers through Multiple Metal Site Interactions in Metal−Organic Frameworks † ○ † ○ † # † † Miguel I. Gonzalez, , Matthew T. Kapelewski, , Eric D. Bloch, , Phillip J. Milner, Douglas A. Reed, § † ∇ † § ∥ † ‡ ⊥ Matthew R. Hudson, Jarad A. Mason, , Gokhan Barin, Craig M. Brown, , and Jeffrey R. Long*, , , † ‡ Department of Chemistry, and Department of Chemical Engineering, University of California, Berkeley, California 94720, United States § Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States ∥ Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States ⊥ Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States *S Supporting Information fi ABSTRACT: Puri cation of the C8 alkylaromatics o-xylene, m- xylene, p-xylene, and ethylbenzene remains among the most challenging industrial separations, due to the similar shapes, boiling points, and polarities of these molecules. Herein, we report the − 4− evaluation of the metal organic frameworks Co2(dobdc) (dobdc = 2,5-dioxido-1,4-benzenedicarboxylate) and Co2(m-dobdc) (m- dobdc4− = 4,6-dioxido-1,3-benzenedicarboxylate) for the separa- tion of xylene isomers using single-component adsorption isotherms and multicomponent breakthrough measurements. Remarkably, Co2(dobdc) distinguishes among all four molecules, with binding affinities that follow the trend o-xylene > ethyl- benzene > m-xylene > p-xylene. Multicomponent liquid-phase adsorption measurements further demonstrate that Co2(dobdc) maintains this selectivity over a wide range of concentrations. Structural characterization by single-crystal X-ray diffraction reveals that both frameworks facilitate the separation through the extent of interaction between each C8 guest molecule with two adjacent cobalt(II) centers, as well as the ability of each isomer to pack within the framework pores.