High Glass Content Non-Shrinking Sol-Gel Composites via Silicic Acid Esters

1992 ◽  
Vol 274 ◽  
Author(s):  
Mark W. Ellsworth ◽  
Bruce M. Novak
Keyword(s):  
Silicic Acid ◽  
Sol Gel ◽  
Glass Content ◽  
Design And Synthesis ◽  
Wide Range ◽  
Sol Gel Process ◽  
Organic Composites ◽  
Acid Esters

ABSTRACTThe application of the sol-gel process for the formation. of inorganic-organic composites has received a great deal of attention in recent years. We have focused our efforts in this area toward the development of simultaneous polymerization/sol-gel reactions for the developement of inorganic-organic composites with a wide range of polymers. Further research in this area has led to the design and synthesis of tetraalkoxysilanes, and more recently, poly(silicic acid esters) possessing polymerizable alkoxides for the synthesis of non-shrinking sol-gel composites.

Organic–inorganic hybrids having a talc-like structure as suitable hosts to guest a wide range of species

2018 ◽  
Vol 47 (9) ◽  
pp. 2925-2932 ◽  
Author(s):  
J. Brendlé
Keyword(s):  
Hybrid Materials ◽  
Sol Gel ◽  
Step Method ◽  
Mild Conditions ◽  
Condensation Reactions ◽  
Wide Range ◽  
Sol Gel Process ◽  
Hydrolysis And Condensation ◽  
One Step

The sol–gel process involving hydrolysis and condensation reactions is an attractive way to form siloxane based hybrid materials since it is a one-step method performed under mild conditions.

Synthesis of Photosensitive Organic-Inorganic Hybrid Polymers via Anhydrous Sol-Gel Process for Integrated Optics

2003 ◽  
Vol 780 ◽  
Author(s):  
Xinshi Luo ◽  
Congji Zha ◽  
Barry Luther-Davies
Keyword(s):  
Low Cost ◽  
Sol Gel ◽  
Optical Loss ◽  
Hybrid Polymer ◽  
Optical Losses ◽  
Hybrid Polymers ◽  
Inorganic Hybrid ◽  
Wide Range ◽  
Integrated Optical ◽  
Sol Gel Process

AbstractPhotosensitive organic-inorganic hybrid polymers were synthesised for integrated optical and optoelectronic devices by a non-hydrous sol-gel process of hydrolysis/condensation of 3-methacryloxypropyltrimethoxysilane (MPS), diphenyldimethoxysilane (DPhDMS), and zirconium isopropoxide (TPZ) with boric acid under anhydrous conditions. The methacryl groups of MPS are UVpolymerizable, which are suitable for low cost fabrication of waveguides with a “UV write/develop” process. The incorporation of DPhDMS and TPZ was found useful in reducing the optical loss and in enhancing the thermostability of the polymer. The refractive index of the hybrid polymer is tuneable from 1.4950 to 1.5360 by variation of the ratio among MPS, DPhDMS and TPZ. Optical characterisation showed that the material has low optical losses at the telecommunications windows (0.16 dB/cm at 1310 nm and 0.4 dB/cm at 1550nm). The hybrid polymer also showed a low birefringence (1.2×10-4), a large thermo-optic (TO) coefficient (-2.77 ×10-4), and an outstanding linearity of dn/dT in a wide range of temperature (from 25 °C to 200 °C). Waveguides forming ability for the hybrid polymer with UV imprinting was also demonstrated.

Recyclable (Fe3O4-NaYF4:Yb,Tm)@TiO2 nanocomposites with near-infrared enhanced photocatalytic activity

2018 ◽  
Vol 47 (5) ◽  
pp. 1666-1673 ◽  
Author(s):  
Yan Lv ◽  
Lin Yue ◽  
Qian Li ◽  
Baoyi Shao ◽  
Sen Zhao ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Self Assembly ◽  
Near Infrared ◽  
Sol Gel ◽  
Design And Synthesis ◽  
Sol Gel Process

Herein, the design and synthesis of a multifunctional (Fe3O4-NaYF4:Yb,Tm)@TiO2 photocatalyst through a facile sol–gel process combined with electrostatic self-assembly has been reported.

scholarly journals Sol-gel Silica Nanoparticles in Medicine: A Natural Choice. Design, Synthesis and Products

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2021 ◽  
Author(s):  
M. Clara Gonçalves
Keyword(s):  
Silica Nanoparticles ◽  
Human Life ◽  
Sol Gel ◽  
Sio2 Nanoparticles ◽  
Short Review ◽  
Biomimetic Synthesis ◽  
Medical Applications ◽  
Gene Target ◽  
Wide Range ◽  
Sol Gel Process

Silica is one of the most abundant minerals in the Earth’s crust, and over time it has been introduced first into human life and later into engineering. Silica is present in the food chain and in the human body. As a biomaterial, silica is widely used in dentistry, orthopedics, and dermatology. Recently amorphous sol-gel SiO2 nanoparticles (NPs) have appeared as nanocarriers in a wide range of medical applications, namely in drug/gene target delivery and imaging diagnosis, where they stand out for their high biocompatibility, hydrophilicity, enormous flexibility for surface modification with a high payload capacity, and prolonged blood circulation time. The sol-gel process is an extremely versatile bottom-up methodology used in the synthesis of silica NPs, offering a great variety of chemical possibilities, such as high homogeneity and purity, along with full scale pH processing. By introducing organic functional groups or surfactants during the sol-gel process, ORMOSIL NPs or mesoporous NPs are produced. Colloidal route, biomimetic synthesis, solution route and template synthesis (the main sol-gel methods to produce monosized silica nanoparticles) are compared and discussed. This short review goes over some of the emerging approaches in the field of non-porous sol-gel silica NPs aiming at medical applications, centered on the syntheses processes used.

Partially Hydrolyzed Alkoxysilanes as Precursors for Silica Aerogels

1988 ◽  
Vol 121 ◽  
Author(s):  
T. M. Tillotson ◽  
L. W. Hrubesh ◽  
I. M. Thomas
Keyword(s):  
Sol Gel ◽  
Silica Aerogels ◽  
Low Density ◽  
Density Range ◽  
Moist Air ◽  
Wide Range ◽  
Sol Gel Process ◽  
Hydrolysis Of ◽  
Highly Porous ◽  
Controlled Hydrolysis

ABSTRACTThe classical sol-gel process for synthesizing SiO2 aerogels involves the hydrolysis/condensation of tetraethyoxysilane (TEOS) and/or teramethyoxysilane (TMOS) to produce a gel which can then be super-critically extracted to a low density, highly porous aerogel glass. Controlled hydrolysis of TEOS and TMOS leads to partially hydrolyzed compounds that can be subsequently water processed to form silica aerogels in the density range from .020 to .500 gms/cc. The partially hydrolyzed compounds are stable when sealed from moist air and can be stored for future use.We discuss the controlled conditions used to obtain these compounds and present data that characterize their structure. We detail the procedures for preparing the wide range of aerogel densities. We also report on their use as an adhesive.

Investigation of Aluminum Content on the Properties of Sol-Gel-Derived Zinc Oxide Thin Films

2007 ◽  
Vol 561-565 ◽  
pp. 1173-1176
Author(s):  
Shu Wen Xue ◽  
Xiao Tao Zu
Keyword(s):  
Sol Gel ◽  
Optical Transmittance ◽  
Atomic Ratio ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Al Content ◽  
Glass Substrates ◽  
Wide Range ◽  
Sol Gel Process

This paper reports that ZnO:Al films were deposited onto glass substrates by sol-gel process. Al/Zn atomic ratio varied in a wide range from 0 ~ 20%. The structural and optical properties were investigated by X-ray diffraction (XRD) and optical transmittance, respectively. X-ray photoemission spectroscopy (XPS) was used to investigate the elemental compositions. XRD results showed that ZnO films remained c-axis-orientated when Al/Zn atomic ratio was below 20% and the grain size decreased with increasing Al content. The optical transmittance showed that the optical bandgap of ZnO films blueshifted with increasing Al/Zn atomic ratio from 0-20%. XPS measurements showed that the binding energy of O1s increased with increasing Al content.

scholarly journals Wood Protective Coatings Prepared with Silanes Based on Fatty Acids

2020 ◽  
Vol 2 (1) ◽  
pp. 24
Author(s):  
Karol Szubert
Keyword(s):  
Wood Surface ◽  
Protective Coatings ◽  
Sol Gel ◽  
Barrier Properties ◽  
Hybrid Coatings ◽  
Organic Layer ◽  
Atmospheric Conditions ◽  
Fatty Acid Derivatives ◽  
Wide Range ◽  
Sol Gel Process

Wood is one of the most important materials in the construction industry. Because of its organic constitution, it is slowly destroyed by the long-term impacts of water, oxygen and light under atmospheric conditions and, hence, needs to be sufficiently protected. Appropriate protection of wood leads to it having longer life and, hence, a huge reduction in maintenance costs. There are several methods to protect wood, either by its chemical modification or by its surface treatment. Unfortunately, many of the wood preservatives that have been used so far are highly toxic to humans and, hence, much attention has been paid to the development of nontoxic materials/methods for the protection of wood. Recently, several reports have been published on the use of inorganic–organic hybrid coatings for the protection of wood substrates. The sol–gel process to generate hybrid coatings is quite versatile and even allows room temperature deposition of hybrid inorganic–organic films on a wide range of substrates, including wood. Wood surface modification with multifunctional alkoxysilanes by the sol–gel process is one promising method to improve and provide new properties for wood materials. The advantage of the sol–gel process is that it allows deposition of a thin inorganic–organic layer on various substrates as a result of controlled hydrolysis and polycondensation of alkoxysilanes. The sol–gel coatings created on the wood surface provide barrier properties, moisture control and repellency properties. In this communication we present new trialkoxysilanes synthesised from fatty acid derivatives and their application in wood protective coatings.

scholarly journals Synthesis of Core–Double Shell Nylon-ZnO/Polypyrrole Electrospun Nanofibers

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2241
Author(s):  
Mihaela Beregoi ◽  
Nicoleta Preda ◽  
Andreea Costas ◽  
Monica Enculescu ◽  
Raluca Negrea ◽  
...  
Keyword(s):  
Sol Gel ◽  
Electrospun Nanofibers ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Zno Film ◽  
X Ray ◽  
Wide Range ◽  
Sol Gel Process ◽  
Sol Gel Synthesis ◽  
Inorganic Layers

Core–double shell nylon-ZnO/polypyrrole electrospun nanofibers were fabricated by combining three straightforward methods (electrospinning, sol–gel synthesis and electrodeposition). The hybrid fibrous organic–inorganic nanocomposite was obtained starting from freestanding nylon 6/6 nanofibers obtained through electrospinning. Nylon meshes were functionalized with a very thin, continuous ZnO film by a sol–gel process and thermally treated in order to increase its crystallinity. Further, the ZnO coated networks were used as a working electrode for the electrochemical deposition of a very thin, homogenous polypyrrole layer. X-ray diffraction measurements were employed for characterizing the ZnO structures while spectroscopic techniques such as FTIR and Raman were employed for describing the polypyrrole layer. An elemental analysis was performed through X-ray microanalysis, confirming the expected double shell structure. A detailed micromorphological characterization through FESEM and TEM assays evidenced the deposition of both organic and inorganic layers. Highly transparent, flexible due to the presence of the polymer core and embedding a semiconducting heterojunction, such materials can be easily tailored and integrated in functional platforms with a wide range of applications.

Thick-Film CO2 Sensors Based on NASICON Synthesized by a Sol-Gel Process

2007 ◽  
Vol 544-545 ◽  
pp. 925-928 ◽  
Author(s):  
Han Ji Kim ◽  
Jung Woon Choi ◽  
Shin Do Kim ◽  
Kwang Soo Yoo
Keyword(s):  
Thick Film ◽  
High Purity ◽  
Electromotive Force ◽  
Screen Printing ◽  
Sol Gel ◽  
Volume Ratio ◽  
Ionic Conductor ◽  
Sensing Properties ◽  
Wide Range ◽  
Sol Gel Process

Thick-film CO2 sensors were fabricated using a sodium super ionic conductor (NASICON: Na1+xZr2SixP3-xO12) with a series of Li2CO3-BaCO3 auxiliary phases. The powder of a precursor of NASICON with high purity was synthesized by a sol-gel process. Using the NASICON paste, an electrolyte was prepared on the alumina substrate through screen printing and then sintered at 1000°C for 5 hours. The resulted NASICON thick film was characterized by XRD and FESEM. Within a wide range of CO2 volume ratio concentration from 1,000 to 10,000 ppm, the output of the sensor showed a good electromotive force (EMF) response that was very close to the theoretical value. The sensor attached with a binary carbonate auxiliary phase Li2CO3-BaCO3 (1:2) showed fairly good CO2 sensing properties at 470°C.

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