Synthesis and Characterization of Ordered Mesoporous Silica Films on Oxidized Silicon Substrates

Synthesis and Characterization of Ordered Mesoporous Silica Films on Oxidized Silicon Substrates PDF Author: David Jacques Picciotto
Publisher:
ISBN:
Category :
Languages : en
Pages : 236

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Book Description
The fabrication of advanced electronic devices that operate on quantum effects requires the patterning of semiconductors on the scale of 50 A, which cannot be achieved by any of the currently available patterning technologies. This project pursued a novel approach: the fabrication of a self-assembling template which would allow the deposition of ordered arrays of germanium dots on silicon substrates, on length scales permitting the operation of quantum devices at room temperature. The template is the mesoporous silicate MCM-41, discovered by researchers at Mobil Chemical Corp. This material consists of highly ordered, two-dimensional, hexagonal arrays of very uniform pores in silicon dioxide, with diameters tunable from 20 A to over 100 A. If pore arrays of this material can be grown as thin films on silicon substrates, with the pores oriented normal to the substrate surface, the resulting structure will provide a template for the deposition of germanium dots. Germanium can then be deposited through the pores in the film and onto the silicon substrates by chemical or physical vapor deposition. The template film can then be etched away, leaving a hexagonally ordered array of germanium dots on the silicon substrate. Mesoporous silica films were grown on oxidized silicon substrates by acidic synthesis. The substrates were first patterned by optical lithography to produce vertical features with dimensions of the order of microns. The substrates were then coated with hydrophobic polymer monolayers to alter their surface energy. This monolayer was selectively removed from the horizontal surfaces of some of the substrates, leaving it only on the vertical surfaces of the patterned features. It was thought that the difference in surface energy between horizontal and vertical surfaces would induce the pores to align along the vertical surfaces.

Synthesis and Characterization of Ordered Mesoporous Silica Films on Oxidized Silicon Substrates

Synthesis and Characterization of Ordered Mesoporous Silica Films on Oxidized Silicon Substrates PDF Author: David Jacques Picciotto
Publisher:
ISBN:
Category :
Languages : en
Pages : 236

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Book Description
The fabrication of advanced electronic devices that operate on quantum effects requires the patterning of semiconductors on the scale of 50 A, which cannot be achieved by any of the currently available patterning technologies. This project pursued a novel approach: the fabrication of a self-assembling template which would allow the deposition of ordered arrays of germanium dots on silicon substrates, on length scales permitting the operation of quantum devices at room temperature. The template is the mesoporous silicate MCM-41, discovered by researchers at Mobil Chemical Corp. This material consists of highly ordered, two-dimensional, hexagonal arrays of very uniform pores in silicon dioxide, with diameters tunable from 20 A to over 100 A. If pore arrays of this material can be grown as thin films on silicon substrates, with the pores oriented normal to the substrate surface, the resulting structure will provide a template for the deposition of germanium dots. Germanium can then be deposited through the pores in the film and onto the silicon substrates by chemical or physical vapor deposition. The template film can then be etched away, leaving a hexagonally ordered array of germanium dots on the silicon substrate. Mesoporous silica films were grown on oxidized silicon substrates by acidic synthesis. The substrates were first patterned by optical lithography to produce vertical features with dimensions of the order of microns. The substrates were then coated with hydrophobic polymer monolayers to alter their surface energy. This monolayer was selectively removed from the horizontal surfaces of some of the substrates, leaving it only on the vertical surfaces of the patterned features. It was thought that the difference in surface energy between horizontal and vertical surfaces would induce the pores to align along the vertical surfaces.

Nanocasting

Nanocasting PDF Author: An-Hui Lu
Publisher: Royal Society of Chemistry
ISBN: 0854041885
Category : Science
Languages : en
Pages : 279

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Book Description
Nanostructured materials with tailored properties are regarded as a fundamental element in the development of future science and technology. Research is still ongoing into the nanosized construction elements required to create functional solids. The recently developed technique, nanocasting, has great advantage over others in terms of the synthesis of special nanostructured materials by the careful choice of suitable elements and nanoengineering steps. This new book summarizes the recent developments in nanocasting, including the principles of nanocasting, syntheses of novel nanostructured materials, characterization methods, detailed synthetic recipes and further possible development in this area. The book focuses on the synthesis of porous solids from the viewpoint of methodology and introduces the science of nanocasting from fundamental principles to their use in synthesis of various materials. It starts by outlining the principles of nanocasting, requirements to the templates and precursors and the tools needed to probe matter at the nanoscale level. It describes how to synthesize nano structured porous solids with defined characteristics and finally discusses the functionalization and application of porous solids. Special attention is given to new developments in this field and future perspectives. A useful appendix covering the detailed synthetic recipes of various templates including porous silica, porous carbon and colloidal spheres is included which will be invaluable to researchers wanting to follow and reproduce nanocast materials. Topics covered in the book include: * inorganic chemistry * organic chemistry * solution chemistry * sol-gel and interface science * acid-base equilibria * electrochemistry * biochemistry * confined synthesis The book gives readers not only an overview of nanocasting technology, but also sufficient information and knowledge for those wanting to prepare various nanostructured materials without needing to search the available literature.

Nanoporous Materials: Science And Engineering

Nanoporous Materials: Science And Engineering PDF Author: G Q Max Lu
Publisher: World Scientific
ISBN: 178326179X
Category : Technology & Engineering
Languages : en
Pages : 911

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Book Description
Porous materials are of scientific and technological importance because of the presence of voids of controllable dimensions at the atomic, molecular, and nanometer scales, enabling them to discriminate and interact with molecules and clusters. Interestingly the big deal about this class of materials is about the “nothingness” within — the pore space. International Union of Pure and Applied Chemistry (IUPAC) classifies porous materials into three categories — micropores of less than 2 nm in diameter, mesopores between 2 and 50 nm, and macropores of greater than 50 nm. In this book, nanoporous materials are defined as those porous materials with pore diameters less than 100 nm.Over the last decade, there has been an ever increasing interest and research effort in the synthesis, characterization, functionalization, molecular modeling and design of nanoporous materials. The main challenges in research include the fundamental understanding of structure-property relations and tailor-design of nanostructures for specific properties and applications. Research efforts in this field have been driven by the rapid growing emerging applications such as biosensor, drug delivery, gas separation, energy storage and fuel cell technology, nanocatalysis and photonics. These applications offer exciting new opportunities for scientists to develop new strategies and techniques for the synthesis and applications of these materials.This book provides a series of systematic reviews of the recent developments in nanoporous materials. It covers the following topics: (1) synthesis, processing, characterization and property evaluation; (2) functionalization by physical and/or chemical treatments; (3) experimental and computational studies on fundamental properties, such as catalytic effects, transport and adsorption, molecular sieving and biosorption; (4) applications, including photonic devices, catalysis, environmental pollution control, biological molecules separation and isolation, sensors, membranes, hydrogen and energy storage, etc./a

Ordered Porous Solids

Ordered Porous Solids PDF Author: Valentin Valtchev
Publisher: Elsevier
ISBN: 0080932452
Category : Science
Languages : en
Pages : 813

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Book Description
The developments in the area of ordered nanoporous solids have moved beyond the traditional catalytic and separation uses and given rise to a wide variety of new applications in different branches of chemistry, physics, material science, etc. The activity in this area is due to the outstanding properties of nanoporous materials that have attracted the attention of researchers from different communities. However, recent achievements in a specific field often remain out of the focus of collaborating communities. This work summarizes the latest developments and prospects in the area of ordered porous solids, including synthetic layered materials (clays), microporous zeolite-type materials, ordered mesoporous solids, metal-organic-framework compounds (MOFs), carbon, etc. All aspects, from synthesis via comprehensive characterization to the advanced applications of ordered porous materials, are presented. The chapters are written by leading experts in their respective fields with an emphasis on recent progress and the state of the art. - Summarizes the latest developments in the field of ordered nanoporous solids - Presents state-of-the-art coverage of applications related to porous solids - Incorporates 28 contributions from experts across the disciplines

Oxide Materials at the Two-Dimensional Limit

Oxide Materials at the Two-Dimensional Limit PDF Author: Falko P. Netzer
Publisher: Springer
ISBN: 3319283324
Category : Technology & Engineering
Languages : en
Pages : 403

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Book Description
This book summarizes the current knowledge of two-dimensional oxide materials. The fundamental properties of 2-D oxide systems are explored in terms of atomic structure, electronic behavior and surface chemistry. The concept of polarity in determining the stability of 2-D oxide layers is examined, charge transfer effects in ultrathin oxide films are reviewed as well as the role of defects in 2-D oxide films. The novel structure concepts that apply in oxide systems of low dimensionality are addressed, and a chapter giving an overview of state-of-the-art theoretical methods for electronic structure determination of nanostructured oxides is included. Special emphasis is given to a balanced view from the experimental and the theoretical side. Two-dimensional materials, and 2-D oxides in particular, have outstanding behavior due to dimensionality and proximity effects. Several chapters treat prototypical model systems as illustrative examples to discuss the peculiar physical and chemical properties of 2-D oxide systems. The chapters are written by renowned experts in the field.

Mesoporous Zeolites

Mesoporous Zeolites PDF Author: Javier García-Martínez
Publisher: John Wiley & Sons
ISBN: 3527335749
Category : Technology & Engineering
Languages : en
Pages : 608

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Book Description
Authored by a top-level team of both academic and industrial researchers in the field, this is an up-to-date review of mesoporous zeolites. The leading experts cover novel preparation methods that allow for a purpose-oriented fine-tuning of zeolite properties, as well as the related materials, discussing the specific characterization methods and the applications in close relation to each individual preparation approach. The result is a self-contained treatment of the different classes of mesoporous zeolites. With its academic insights and practical relevance this is a comprehensive handbook for researchers in the field and related areas, as well as for developers from the chemical industry.

Modern Inorganic Synthetic Chemistry

Modern Inorganic Synthetic Chemistry PDF Author: Ruren Xu
Publisher: Elsevier
ISBN: 0444635955
Category : Science
Languages : en
Pages : 810

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Book Description
Modern Inorganic Synthetic Chemistry, Second Edition captures, in five distinct sections, the latest advancements in inorganic synthetic chemistry, providing materials chemists, chemical engineers, and materials scientists with a valuable reference source to help them advance their research efforts and achieve breakthroughs. Section one includes six chapters centering on synthetic chemistry under specific conditions, such as high-temperature, low-temperature and cryogenic, hydrothermal and solvothermal, high-pressure, photochemical and fusion conditions. Section two focuses on the synthesis and related chemistry problems of highly distinct categories of inorganic compounds, including superheavy elements, coordination compounds and coordination polymers, cluster compounds, organometallic compounds, inorganic polymers, and nonstoichiometric compounds. Section three elaborates on the synthetic chemistry of five important classes of inorganic functional materials, namely, ordered porous materials, carbon materials, advanced ceramic materials, host-guest materials, and hierarchically structured materials. Section four consists of four chapters where the synthesis of functional inorganic aggregates is discussed, giving special attention to the growth of single crystals, assembly of nanomaterials, and preparation of amorphous materials and membranes. The new edition's biggest highlight is Section five where the frontier in inorganic synthetic chemistry is reviewed by focusing on biomimetic synthesis and rationally designed synthesis. - Focuses on the chemistry of inorganic synthesis, assembly, and organization of wide-ranging inorganic systems - Covers all major methodologies of inorganic synthesis - Provides state-of-the-art synthetic methods - Includes real examples in the organization of complex inorganic functional materials - Contains more than 4000 references that are all highly reflective of the latest advancement in inorganic synthetic chemistry - Presents a comprehensive coverage of the key issues involved in modern inorganic synthetic chemistry as written by experts in the field

International Aerospace Abstracts

International Aerospace Abstracts PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 974

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Book Description


Book of Abstracts

Book of Abstracts PDF Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 778

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Book Description


Characterization of Pharmaceutical Nano- and Microsystems

Characterization of Pharmaceutical Nano- and Microsystems PDF Author: Leena Peltonen
Publisher: John Wiley & Sons
ISBN: 1119414040
Category : Science
Languages : en
Pages : 410

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Book Description
Learn about the analytical tools used to characterize particulate drug delivery systems with this comprehensive overview Edited by a leading expert in the field, Characterization of Pharmaceutical Nano- and Microsystems provides a complete description of the analytical techniques used to characterize particulate drug systems on the micro- and nanoscale. The book offers readers a full understanding of the basic physicochemical characteristics, material properties and differences between micro- and nanosystems. It explains how and why greater experience and more reliable measurement techniques are required as particle size shrinks, and the measured phenomena grow weaker. Characterization of Pharmaceutical Nano- and Microsystems deals with a wide variety of topics relevant to chemical and solid-state analysis of drug delivery systems, including drug release, permeation, cell interaction, and safety. It is a complete resource for those interested in the development and manufacture of new medicines, the drug development process, and the translation of those drugs into life-enriching and lifesaving medicines. Characterization of Pharmaceutical Nano- and Microsystems covers all of the following topics: An introduction to the analytical tools applied to determine particle size, morphology, and shape Common chemical approaches to drug system characterization A description of solid-state characterization of drug systems Drug release and permeation studies Toxicity and safety issues The interaction of drug particles with cells Perfect for pharmaceutical chemists and engineers, as well as all other industry professionals and researchers who deal with drug delivery systems on a regular basis, Characterization of Pharmaceutical Nano- and Microsystems also belongs on bookshelves of interested students and faculty who interact with this topic.