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.

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.

Structure-Related Mechanical Properties of Ormosils by SOL-GEL Process

1992 ◽  
Vol 271 ◽  
Author(s):  
Yi Hu ◽  
John D. Mackenzie
Keyword(s):  
Mechanical Properties ◽  
Reaction Temperature ◽  
Fracture Strength ◽  
Modulus Of Elasticity ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Polydimethyl Siloxane ◽  
Organically Modified Silicates ◽  
Sol Gel Process ◽  
Organically Modified

ABSTRACTThe mechanical properties corresponding to the different structures of organically modified silicates (Ormosils) prepared by the sol-gel process were studied. Tetraethoxysilane (TEOS) and polydimethyl siloxane (PDMS) were used as the inorganic and polymeric components, respectively. Large variations in the microstructure of the Ormosils were found by changing the reaction temperature, and the content of PDMS, acid catalyst (HCI),and water. The structure of the Ormosils and the mechanical properties were correlated by the edge connectivity. Modulus of elasticity and fracture strength were used to study their relations Ormosils structures.

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.

Prospects for Chemical Control and Engineering of Organically Modified Ceramics

1998 ◽  
Vol 550 ◽  
Author(s):  
Stephen E. Rankin ◽  
Alon V. McCormick
Keyword(s):  
Material Properties ◽  
Chemical Control ◽  
Sol Gel ◽  
Polymer Structure ◽  
New Materials ◽  
Reliable Model ◽  
Organically Modified ◽  
Silicon Alkoxides ◽  
Simple Pair ◽  
Kinetics Of

AbstractHydrolytic polycondensation of silicon alkoxides and organically modified alkoxides shows promise as a route to new materials for medicine. Mathematical models of this polymerization accelerate the development of these materials and processes for their production. With a reliable model, one can rapidly explore a wide variety of options for controlling material properties. Here we describe a model for kinetics of sol-gel copolymerization of a simple pair of ethoxysilanes: (CH3)3Si(OC2H5) and (CH3)2Si(OC2H5)2. We then describe how reactor configuration alone can be used to control of polymer structure by choosing how to mix the reactants. An example is shown of maximizing homogeneity at any reactor residence time of interest in the model copolymer system by using the time of addition of the faster-reacting monomer.

Synthesis of long ZrTiO4 fibers by a sol–gel process free of organic components

2003 ◽  
Vol 13 (5) ◽  
pp. 1127-1131 ◽  
Author(s):  
Qifang Lu ◽  
Dairong Chen ◽  
Xiuling Jiao
Keyword(s):  
Sol Gel ◽  
Organic Components ◽  
Sol Gel Process

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.

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