Organic-inorganic Nanocomposite Membranes from Highly Ordered Mesoporous Thin Films for Solubility-based Separations PDF Download

Author: Suk Joon Yoo
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Solubility-based membrane separation, in which the more soluble species preferentially permeates across the membrane, has attracted considerable recent attention due to both economic and environmental concerns. This solubility-selective mode is particularly attractive over a diffusivity-selective mode in applications in which the heavier species are present in dilute concentrations. Examples include the recovery of volatile organic components (VOCs) from effluent streams and the removal of higher hydrocarbons from natural gas. Recently, nanocomposites have shown great promise as possible membrane materials for solubility-selective separations. The chemical derivatization of inorganic mesoporous substrates has been explored to synthesize organic-inorganic nanocomposite membranes. The most exciting feature of this approach is that it enables the rational engineering of membrane nano-architecture with independent control over the free volume and chemistry to create membranes with highly customizable permselectivity properties. In this study, we synthesized the organic-inorganic nanocomposite membranes by decorating the surfaces of commercially available mesoporous alumina substrates, and surfactant-templated highly ordered mesoporous silicate thin films placed on commercially available macroporous inorganic substrates, with a selective organic material that is physically or chemically anchored to the porous surfaces. Hyperbranched melamine-based dendrimers, with nanometer dimension and chemical composition designed to target certain components, were used as filling agents. We evaluated these membranes for several environmentally relevant separations, such as the recovery of the higher hydrocarbon from air and the removal of trace VOCs from air or water, while exploring the impact of organic oligomer size, chemistry, and surface coverage, as well as substrate pore size and structure, on membrane performance. First, we did a model study to verify the feasibility of dendrimer growth inside mesopores by using ordered mesoporous silica. Alumina-ordered mesoporous silica (alumina-OMS) hybrid membranes were prepared as new inorganic porous substrates. Finally, we synthesized dendrimer-ceramic nanocomposite membranes by growing several generations of melamine-based dendrimers with diverse functional groups directly off the commercial alumina membranes. Composite membranes show very high propane/nitrogen selectivity up to 70.

Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 1006

View

Book Description

Author: Seung Uk Yeu
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
Over the past few decades there has been great interest in exploring alternatives to conventional separation methods due to their high cost and energy requirements. Membranes offer a potentially attractive alternative as they potentially address both of these points. The overarching theme of this dissertation is to design nanocomposite membranes for processes where existing separation schemes are inadequate. This dissertation focuses on three challenges: 1) designing organic-inorganic hybrid membranes for reverse-selective removal of alkanes from light gases, 2) defect-free inorganic nanocomposite membranes that have uniform pores, and 3) nanocomposite membranes for minimizing protein fouling in microfiltration applications. Reverse-selective gas separations that preferentially permeate larger/heavier molecular species based on their greater solubility have attracted considerable recent attention due to both economic and environmental concerns. In this study, dendrimer-ceramic hybrid membranes showed exceptionally high propane/nitrogen selectivities. This result was ascribed to the presence of stable residual solvent that affects the solubility of hydrocarbon species. Mesoporous silica-ceramic nanocomposite membranes have been fabricated to provide defectless mesoporous membranes. As mesoporous silica is iteratively synthesized in the ceramic macropores, the coating method and the surfactant removal step significantly affected permeance and selectivity. It was also shown that support layers can cause a lower selectivity than Knudsen limit. Membrane fouling which results from deposition and nonspecific adsorption of proteins on the membrane surface is irreversible in nature, and results in a significant decrease in the membrane performance. To address this problem, two approaches were explored: 1) control of the surface chemistry tethering alumina membranes with organic components and 2) development of a novel photocatalytic membrane that exhibits hydrophilicity and can be easily regenerated. Both approaches can offer a viable route to the synthesis of attractive membranes, in that 1) the density of protein-resistant organic groups such as PEG is controllable by changing scaffolds or synthesis conditions and 2) the photocatalytic nanocomposite membranes can open the way for a new regeneration method that is environmentally benign.

Author: Wanqin Jin
Publisher: World Scientific
ISBN: 1786342936
Category : Technology & Engineering
Languages : en
Pages : 312

View

Book Description
This book gives comprehensive information on the design, preparation and application of organic-inorganic composite membranes that are used for molecular separation. Various membrane types with different materials are highlighted, including polymer/ceramic composite membranes, mixed matrix membranes, metal-organic frameworks membranes and graphene-based membranes. Physical and chemical properties, morphologies, interfacial behaviors, transport characteristics and separation performance of the organic-inorganic composite membranes are thoroughly discussed based on advanced characterization techniques.Meanwhile, the book contains several typical applications of the membranes in fields such as bio-fuels production, organic compounds recovery, solvent dehydration, carbon dioxide capture and others. In addition, large-scale production and industrial implementation of the organic-inorganic composite membranes are briefly introduced.

Author: Parveen Kumar
Publisher:
ISBN:
Category :
Languages : en
Pages : 250

View

Book Description
Ordered mesoporous films and membranes refer to materials in a thin layer geometry possessing pore diameters in the 2-50 nm range. Their extremely high surface areas (up to ~ 1000 m2/g) and precise tuning of pore sizes are among the many desirable properties that have made such thin films and membranes a focus of great attention for emerging applications in the synthesis of nanomaterials and separation membranes. Ordered mesoporous silica films are highly promising hosts to grow semiconductor nanoparticles with fine-tuned size if the film thickness, pore size and orientation can be controlled. This important potential use of ordered mesoporous silica materials is one major focus area of this dissertation. Ordered mesoporous silica thin films can also be grown as membrane layers on poroussupports possessing three-dimensionally interconnected pore structures. The investigation of ordered mesoporous silica membranes modified by amine groups for CO2 separation is another major focus area of this work. Potential application of these membranes is to capture CO2 from flue gas which is a critical step preceding a variety of CO2 sequestration approaches to curb its atmospheric emissions. We systematically investigated the effect of pore size and pore symmetry on the growth of CdS nanoparticles inside the functionalized ordered mesoporous silica hosts. The 2D hexagonal mesoporous silica, SBA-15 possessing 4-22 nm pores and 3D cubic SBA-16 with 5 nm pores was employed to investigate the effect of pore size and pore symmetry on the microstructure of resulting CdS nanoparticles. As the pore size of SBA-15 increased, an increase in the average size of the CdS nanocrystals was observed. The pore size distributions of the CdS/SBA-15 and CdS/SBA-16 composites suggested that CdS nanoparticles nucleated primarily in the micropores of SBA-15 and SBA-16 hosts. Furthermore, SBA-16 possessing smaller pores as compared to SBA-15 resulted in larger crystal sizes of CdS nanoparticles. These results provided new important insights into the mechanism of initial growth of CdS nanoparticles inside the pores of mesoporous silica hosts possessing different pore symmetries. Ordered mesoporous MCM-48 membranes possessing a cubic pore structure were prepared by solution growth method on -alumina supports. The surfactant was removed by calcination and Soxhlet extraction. The best quality membranes were obtained when the surfactant was removed by extraction. The membranes prepared on asymmetric - alumina supports displayed higher gas permeance (N2 permeance> 2x 10-7 mol/m2.s. Pa) than those fabricated on symmetric supports (N2 permeance

Author: Andrew Livingston
Publisher: Newnes
ISBN: 9780444537447
Category : Science
Languages : en
Pages : 0

View

Book Description
Separation of molecules present in organic solvents by membrane (nano)filtration has great potential in industries ranging from refining to fine chemical and pharmaceutical synthesis and is currently an area of intensive studies. This will be the first concise reference book offering a critical analysis on this topic. Nanofiltration, is a pressure driven membrane process used to remove solutes with molecular weight in the range of 200-1,000 g mol-1 typically from aqueous streams. A recent innovation is the extension of nanofiltration processes to organic solvents an emerging technology referred to as Organic Solvent Nanofiltration (OSN). Separation of molecules present in organic solvents by nanofiltration has great potential in various processes such as petroleum refining, fine chemical and pharmaceutical synthesis, catalyst recycle, enrichment of aromatics etc. This book summarizes the developments in the field of OSN. It describes materials and methods used for the preparation of organic solvent stable membranes. Various techniques for manufacturing of OSN membranes, their physico-chemical and performance related characterization and membrane transport mechanisms will be discussed and critically evaluated. A summary of the commercially available OSN membranes, their separation properties and manufacturers will also be presented. Finally a detailed overview of the OSN applications in various industrial and laboratory scale processes as well as their future prospective will be presented. Complete coverage of the field of organic Solvent Nanofiltration: theory and industrial applications Provides all you want to know in this fast developing application of membranes in industrial filtration and water purification Applications of membranes - summary of the existing applications and proposed new applications; review and critical analysis of the data on currently available OSN membranes. The benefit of this feature to the users is outlined in the comment of one referee: "I use these types of books as an instant reference, resource and fact checker when I am writing or researching topics in membrane technology. I also read the content carefully to keep myself at the state-of-the-art in the technology. R&D is an expensive and time consuming endeavor so anything learned from the literature is valuable when it helps to guide my efforts". Contains a large number of diagrams /figures (60 approx) which offer graphical explanations of the processes and the mechanisms underlying the processess provides practical and easy to understand examples of practical applications. The user can easily adapt these to his/her specific application Worked examples 15 (approx) Guide the reader through the various parameters, and show the reader the effect of these parameters in the overall design of the process Includes multimedia content, videos and active tables and diagrams Enable the user to add his/her own data and conditions and get results relevant to his/her situation. Tables (25 approx) Provides review and critical analysis of the data on currently available OSN membranes Glossary Summary of the main terms used in OSN

Author:
Publisher:
ISBN:
Category : Chemistry, Technical
Languages : en
Pages : 460

View

Book Description

Author: Pei Sean Goh
Publisher: Elsevier
ISBN: 0128194073
Category : Technology & Engineering
Languages : en
Pages : 312

View

Book Description
The development of a new class of nanocomposite membranes has served as one of the most prominent strategies to address the intrinsic limitations of conventionally used polymeric and inorganic membranes. Nanocomposite membranes consist of nanosized inorganic nanomaterials that are incorporated into the structure of continuous polymer matrices. Owing to the exceptional properties exhibited by the nanomaterials, the resultant nanocomposite membranes demonstrate higher selectivity and permeability that surpass the Robeson upper boundary limit. Nanocomposite Membranes for Gas Separation provides a comprehensive review of the advances made in the development and application of gas separation nanocomposite membranes. In particular, the book covers the focuses on the fabrication, modification, characterization and applications of nanocomposite membranes for gas separation. It is an important reference source both for materials scientists, environmental engineers and chemical engineers who are looking to understand how nanocomposite membranes are being used to create better techniques for gas separation. Provides detailed insights in the fabrication, modification, characterization and applications of nanocomposite membranes for gas separation Shows how nanotechnology is being used to address current limitations of the development of polymeric and inorganic membranes for gas separation, including low separation performance in terms of permeability and selectivity Explores the potential of nanocomposite membranes to help create more effective gas separation techniques

Author: Klaus-Viktor Peinemann
Publisher: John Wiley & Sons
ISBN: 9783527631414
Category : Technology & Engineering
Languages : en
Pages : 251

View

Book Description
This ready reference on Membrane Technologies for Water Treatment, is an invaluable source detailing sustainable, emerging processes, to provide clean, energy saving and cost effective alternatives to conventional processes. The editors are internationally renowned leaders in the field, who have put together a first-class team of authors from academia and industry to present a highly approach to the subject. The book is an instrumental tool for Process Engineers, Chemical Engineers, Process Control Technicians, Water Chemists, Environmental Chemists, Materials Scientists and Patent Lawyers.

Author: Theodor Schneller
Publisher: Springer Science & Business Media
ISBN: 3211993118
Category : Technology & Engineering
Languages : en
Pages : 801

View

Book Description
This is the first text to cover all aspects of solution processed functional oxide thin-films. Chemical Solution Deposition (CSD) comprises all solution based thin- film deposition techniques, which involve chemical reactions of precursors during the formation of the oxide films, i. e. sol-gel type routes, metallo-organic decomposition routes, hybrid routes, etc. While the development of sol-gel type processes for optical coatings on glass by silicon dioxide and titanium dioxide dates from the mid-20th century, the first CSD derived electronic oxide thin films, such as lead zirconate titanate, were prepared in the 1980’s. Since then CSD has emerged as a highly flexible and cost-effective technique for the fabrication of a very wide variety of functional oxide thin films. Application areas include, for example, integrated dielectric capacitors, ferroelectric random access memories, pyroelectric infrared detectors, piezoelectric micro-electromechanical systems, antireflective coatings, optical filters, conducting-, transparent conducting-, and superconducting layers, luminescent coatings, gas sensors, thin film solid-oxide fuel cells, and photoelectrocatalytic solar cells. In the appendix detailed “cooking recipes” for selected material systems are offered.