scholarly journals Inorganic-Organic Composites by Sol-Gel Techniques

1989 ◽  
Vol 171 ◽  
Author(s):  
Helmut Schmidt
Keyword(s):  
Functional Properties ◽  
Structural Modification ◽  
Sol Gel ◽  
Surface Hardness ◽  
Structural And Functional Properties ◽  
Sol Gel Process ◽  
Polymeric Chains ◽  
Organically Modified ◽  
Structural Surface ◽  
Inorganic Organic Polymers

ABSTRACTThe sol-gel process opens the possibility of combining inorganic and organic units to new hybrid polymers. Organic units can be used for structural modification of the inorganic backbone, for creating new functions within an inorganic network and for building up organic polymeric chains. The materials show interesting perspectives with respect to structural (surface hardness, strength) and functional properties (e. g. diffusion, photocuring, incorporation of dyes, optical properties). A review over structural and functional properties of sol-gel derived inorganic-organic polymers (ORMOCERs = organically modified ceramics) is given.

scholarly journals Chemistry And Applications Of Inorganic-Organic Polymers (Organically Modified Silicates)

1986 ◽  
Vol 73 ◽  
Author(s):  
H. Schmidt ◽  
B. Seiferling
Keyword(s):  
Sol Gel ◽  
Inorganic Materials ◽  
Organic Polymers ◽  
Polymeric Networks ◽  
Organically Modified Silicates ◽  
Sol Gel Process ◽  
Organically Modified ◽  
Polycondensation Process ◽  
Application Potential ◽  
Inorganic Organic Polymers

ABSTRACTThe combination of inorganic polymeric networks with organic components leads to inorganic-organic polymers. A convenient method for the introduction of organic radials into an inorganic backbone is the use of organosubstituted silico esters in a polycondensation process. This leads to≡Si-O-Si≡ network containing materials, so-called organically modified silicates (ORMOSILs). For the synthesis of the inorganic backbone, in opposition to the high temperature preparation of non-metallic inorganic materials like ceramics, “soft chemistry” methods have to be applied in order to preserve organic groupings to be incorporated. Therefore, the sol-gel process is a suitable technique [1–5]. A review over basic synthesis principles and chemical methods, their effect on special material properties and the application potential will be given.

Influence of Coumarin Dyes on the Laser Performance of Pyrromethene and Perylene Dyes Co-Doped into ORMOSILs

2007 ◽  
Vol 336-338 ◽  
pp. 574-576
Author(s):  
Hua Rong ◽  
Chun Fang Ye ◽  
Yu Yang ◽  
Guo Dong Qian ◽  
Zhi Yu Wang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Laser Wavelength ◽  
Laser Dyes ◽  
Co Doping ◽  
Organically Modified Silicates ◽  
Sol Gel Process ◽  
Organically Modified ◽  
Transfer Mechanisms ◽  
Co Doped ◽  
Coumarin Dyes

Laser dyes perylene red (p-red) or pyrromethene 567 (p567) were co-doped with coumarin 440 (C440) or coumarin 500 (C500) into MTES- and VTES-derived organically modified silicates (ORMOSILs) by sol-gel process. The effects of coumarin dye concentration on the laser performances of p-red and p567 were investigated. The results from laser efficiency measurements illustrated that at optimized coumarin concentration, the slope efficiency of co-doped p-red increased by a factor of 2 while that of co-doped p567 increased marginally. It was also found that by co-doping coumarin, the laser wavelength of p-red blue shifted and the laser thresholds for p567 and p-red could be reduced. The energy transfer mechanisms involved were also discussed.

Structural and functional properties of sol-gel synthesized and microwave heated Pb0.8 Co0.2-zLazTiO3 (z = 0.05–0.2) nanoparticles

2018 ◽  
Vol 44 (16) ◽  
pp. 19408-19420 ◽  
Author(s):  
N. Suresh Kumar ◽  
R. Padma Suvarna ◽  
K. Chandra Babu Naidu ◽  
G. Ranjith Kumar ◽  
S. Ramesh
Keyword(s):  
Functional Properties ◽  
Sol Gel ◽  
Structural And Functional Properties

Effect of Praseodymium Species on the Structural and Functional Properties of Nanocrystalline BiFeO3 Powders and Thin Films

2012 ◽  
Vol 1454 ◽  
pp. 39-44
Author(s):  
Gina Montes Albino ◽  
Marco Gálvez-Saldaña ◽  
Oscar Perales-Pérez
Keyword(s):  
Thin Films ◽  
Crystallite Size ◽  
Functional Properties ◽  
Doping Level ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ferroelectric Behavior ◽  
Structural And Functional Properties

ABSTRACTThe present study addressed the effect of the incorporation of Praseodymium species in the BiFeO3(BFO) structure on the corresponding structural and functional properties of powders and films. The level of the doping species varied from 0 at% to 4 at%. BFO powders and thin films were synthesized by a sol-gel method, where glycol was aggregated to the main solvent to increase the viscosity of the precursor solutions and promote their adhesion onto platinum substrates. The development of the host BFO structure was confirmed by XRD analyses of samples annealed at 700°C for one hour (powders) or 500°C for 2 hours (thin films), in air. The average crystallite size varied from 37 nm to 41 nm and 28nm to 40nm for powders and thin films, respectively, due to the increase of the doping level. The incorporation of specific dopant species played an important role in the ferromagnetic and ferroelectric behavior in the material.

Microencapsulation of Oil in Organically Modified Silicate Glass by Sol-Gel Process

2002 ◽  
Vol 726 ◽  
Author(s):  
Sang I. Seok ◽  
Bok Y. Ahn ◽  
Joo H. Kim ◽  
Tae S. Suh
Keyword(s):  
Controlled Release ◽  
Sol Gel ◽  
Microemulsion System ◽  
Processing Parameter ◽  
Active Core ◽  
Spherical Silica ◽  
Sol Gel Process ◽  
Organically Modified ◽  
Oil Mixtures ◽  
Silica Precursor

AbstractMicroencapsulation provides protection and sustained or controlled release of active core agents. The sol-gel process has opened up a new way for encapsulating oil droplets within an inorganic capsule. Silica microcapsules were prepared in silica precursor-oil mixtures/NH4OH water microemulsion system. In this step, the formation of capsules incorporating oil depended strongly on the type of silica precursor. A spherical silica microsheres were only obtained when oligomer, synthesized by the hydrolysis and co-condensation of equiweight of TEOS (tetraethylorthosilicate) and MTMS (methyltrimethoxysilane), was used as the wall materials. The particles size of silica microcapsules was in the range of 1 ∼ 100 μm, depending on processing parameter such as a shear rate and O/W ratio etc. In controlled release system, the shell porosity is important to give an appropriate permeability, corresponding to the release rate. The pore structure, responsible for permeability, was adjusted by doping alkyl silane, and investigated with nitrogen sorption measurement.

Effect of Ca and Ag doping on the functional properties of BiFeO3 nanocrystalline powders and films

2014 ◽  
Vol 1675 ◽  
pp. 105-111 ◽  
Author(s):  
Gina Montes Albino ◽  
Oscar Perales-Pérez ◽  
Boris Renteria-Beleño ◽  
Yarilyn Cedeño-Mattei
Keyword(s):  
Thin Films ◽  
Functional Properties ◽  
Bismuth Ferrite ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Nitrogen Atmosphere ◽  
Nanocrystalline Powders ◽  
Systematic Evaluation ◽  
Gel Method ◽  
Structural And Functional Properties

ABSTRACTThe present work addresses the systematic evaluation of the influence of the incorporation of dopant species (Ca+2, Ag+1) on the structural and functional properties of bismuth ferrite (BFO) nanocrystalline powders and films. Pure and doped BFO powders and thin films were synthesized by a modified sol-gel method. The concentration of the doping species varied from 0 up to 7 at %. The development of the host BFO structure was confirmed by XRD analyses of samples annealed at 700°C for one hour in air and nitrogen atmosphere. Thicknesses of films varied between 80 and 200 nm, depending on the concentration of Ca+2 species. Doped BFO exhibited a magnetic behavior that turned from paramagnetic into ferrimagnetic with the increase of Ca+2 concentrations.

scholarly journals Structural and Functional Properties of Fluorinated Silica Hybrid Barrier Layers on Flexible Polymeric Foil

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 573
Author(s):  
Kamila Startek ◽  
Anna Szczurek ◽  
Thi Ngoc Lam Tran ◽  
Justyna Krzak ◽  
Alicja Bachmatiuk ◽  
...  
Keyword(s):  
Functional Properties ◽  
Sol Gel ◽  
Thermomechanical Analysis ◽  
Silica Network ◽  
Silica Coatings ◽  
Structural And Functional Properties ◽  
Microscopic Studies ◽  
Fluorinated Carbon ◽  
Scratch Tests ◽  
Inorganic Structure

The reported work was focused on sol–gel-derived organically modified and fluorinated silica coatings deposited on elastic polymeric foil. The structure and topography of the coatings were tested by infrared spectroscopy and microscopic studies. The functional properties were determined using thermal analysis, surface analysis, and oxygen permeability tests. The barrier feature of the investigated materials against oxygen was correlated with the properties of the coatings. The hybrid (organic–inorganic) structure of the coatings was proven, demonstrating the presence of a silica network modified with alkyl and fluoroalkyl groups since precursors with the isooctyl group or different lengths of the fluoroalkyl chains were used for the syntheses. The coatings were free of defects and had a smooth surface except for the sample containing the longest fluoroalkyl chain (perfluorododecyl group), which showed a wrinkle-like surface. The hydrophobic character of the coatings increased, whereas the oxygen permeation coefficient values decreased (reaching a fourfold lower coefficient in comparison to the bare substrate) with a higher content of the fluorinated carbon atoms in the structure. The results were enriched by the information from the thermomechanical analysis as well as nanoindentation and scratch tests giving values of the glass transition temperature, thermal expansion coefficient, coatings adhesion, and hardness of the investigated systems.

scholarly journals A Comparison of Different A-, A-B-, and B-Site Incorporated in (Ba0.5Sr0.5)TiO3 on Photocatalytic Application

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Tassanee Tubchareon ◽  
Rachan Klaysri ◽  
Piyasan Praserthdam
Keyword(s):  
Methylene Blue ◽  
Structural Modification ◽  
Oxygen Vacancies ◽  
Sol Gel ◽  
Lattice Oxygen ◽  
Photocatalytic Decolorization ◽  
Chemisorbed Oxygen ◽  
Photocatalytic Application ◽  
Sol Gel Process ◽  
A Site

The structural modification of Ba0.5Sr0.5TiO3 (BST) nanocatalyst was successfully synthesized via sol-gel process. The BST catalyst was modified by A-site (A-BST), A-B-site (A-B-BST), and B-site (B-BST) in order to investigate the effect of structurally modified BST catalyst for photocatalytic decolorization of methylene blue. The structurally modified BST catalysts can increase the nonradiation energy such as phonon energy compared to that of BST one. The partial incorporation of the A-BST catalyst was evidenced by the higher-ordered structure by increasing number of Ti4+ ions and the lattice oxygen. The A-B-BST and A-BST catalysts were given more electron-transfer in the TiO6 than that of BST and B-BST catalysts, respectively. The A-B-BST catalyst promoted the oxidation of the lattice oxygen by holes capturing to form the chemisorbed oxygen, presenting the highest photobleaching activity of methylene blue. On the other hand, more oxygen vacancies recombination of BST catalyst compared to that of structurally modified BST catalysts presented the reduction of photocatalytic activity.

scholarly journals Organically Modified Silicates by the Sol-Gel Process

1984 ◽  
Vol 32 ◽  
Author(s):  
H. Schmidt
Keyword(s):  
Sol Gel ◽  
New Materials ◽  
Organic Components ◽  
Organically Modified Silicates ◽  
Sol Gel Process ◽  
Inorganic As ◽  
Organically Modified ◽  
General Aspects

ABSTRACTThe introduction of organic groups into inorganic networks by the sol-gel process opens the possibility for the preparation of new materials, and typical properties resulting from inorganic as well as from organic components may be combined. Some general aspects and different examples of material developments are reviewed.

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