Macroporous Materials with Uniform Pores by Emulsion Templating

1997 ◽  
Vol 497 ◽  
Author(s):  
A. Imhof ◽  
D. J. Pine
Keyword(s):  
Colloidal Crystal ◽  
Sol Gel ◽  
Ordered Structure ◽  
Left Behind ◽  
Ordered Arrays ◽  
Emulsion Droplets ◽  
Sol Gel Process ◽  
Uniform Droplets ◽  
Emulsion Templating ◽  
Regular Arrays

ABSTRACTA method was developed for the production of macroporous oxide materials by using the droplets of a nonaqueous emulsion as the templates around which material is deposited through a sol-gel process. Moreover, uniform pores arranged in regular arrays can be obtained by starting with an emulsion of uniform droplets. These droplets first self-assemble into a colloidal crystal after which gelation of the suspending sol-gel mixture captures the ordered structure. After drying and calcination pellets are obtained which contain ordered arrays of spherical pores left behind by the emulsion droplets. The method can be used to make uniform pores in the range from 0.05–5 micrometers in many different materials. We demonstrate the process for titania, silica, and zirconia.

In Vitro Culture of Osteoblasts with Three Dimensionally Ordered Macroporous Sol-Gel Bioactive Glass (3DOM-BG) Particles

2005 ◽  
Vol 284-286 ◽  
pp. 655-658 ◽  
Author(s):  
Kai Zhang ◽  
Newell R. Washburn ◽  
Joseph M. Antonucci ◽  
Carl G. Simon
Keyword(s):  
Body Fluid ◽  
Colloidal Crystal ◽  
Sol Gel ◽  
Molar Fraction ◽  
Bioactive Glasses ◽  
Templating Method ◽  
Sol Gel Process ◽  
Colloidal Crystal Templating ◽  
Ordered Macroporous

Three dimensionally ordered macroporous sol-gel bioactive glasses (3DOM-BGs)are a type of biomaterial that is both bioactive and resorbable. In this study, 80 % SiO2 – 20 % CaO (molar fraction) 3DOM-BG particles were prepared using a colloidal crystal templating method via a sol-gel process. The as-prepared 3DOM-BG particles can quickly convert to a calcium-deficient, bone-like apatite after soaking in a simulated body fluid (SBF). MC3T3-E1 osteoblastic cells were cultured in the presence of 3DOM-BG particles. Preliminary results from cell studies showed that 3DOM-BG particles are not cytotoxic and are compatible with MC3T3-E1 osteoblast-like cells in vitro.

Preparation of ZrO2 Micro Beads by Sol-Gel Method

2012 ◽  
Vol 512-515 ◽  
pp. 269-274
Author(s):  
S.C. Hao ◽  
X.Y. Zhao ◽  
J.T. Ma ◽  
X.W. Zhou ◽  
T.X Liang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Nitrate Solution ◽  
Spherical Shape ◽  
Ammonia Solution ◽  
Liquid Droplets ◽  
X Ray Diffraction ◽  
Dispersion Method ◽  
Ammonia Gas ◽  
Sol Gel Process ◽  
Uniform Droplets

ZrO2 micro beads are widely used as abrasive media in many areas. This paper introduces a sol-gel process for preparation of ZrO2 micro beads. First, zirconium nitrate solution and urea were mixed to prepare the sol, then the sol was converted to uniform droplets by vibrating dispersion method. The droplets were emitted from the nozzles into an ammonia solution. Along the way from the nozzle to ammonia solution, the liquid droplets first form spherical shape by their surface tension in air, and were then surface-hardened through ammonia gas. The microspheres complete gelation in the ammonia solution. The gel spheres were treated successively by aging, washing, drying, calcination and sintering to yield ZrO2 ceramic micro beads. The crystal structure of micro beads was examined by X-ray diffraction (XRD). The microstructure of the micro beads was observed by scanning electron microscopy (SEM). The results indicate that the sol-gel process can be used to prepare ZrO2 ceramic micro beads with good sphericity and uniform distribution of diameter.

Neurotransmitter release mechanisms and microtubules

1983 ◽  
Vol 218 (1211) ◽  
pp. 253-258 ◽  
Keyword(s):  
Neurotransmitter Release ◽  
Synaptic Vesicles ◽  
Ordered Structure ◽  
Presynaptic Membrane ◽  
Vesicle Membrane ◽  
Ordered Arrays ◽  
The Central Nervous System ◽  
Active Zones ◽  
Dense Projections ◽  
Regular Arrays

The morphological mechanisms involved in translocation of the synaptic vesicle to the presynaptic membrane, release of transmitter from the vesicle and recycling of the vesicle membrane are still far from understood. However, there is strong evidence that vesicles move along the surfaces of a specific set of highly labile presynaptic microtubules that direct the vesicles to the active zones. These microtubules are focused in a precise geometrical array, which is in register with and in contact with presynaptic dense projections of the central nervous system synapse or presynaptic dense bars of the motor endplate. These dense complexes constitute the presynaptic grid or active zones. The regular arrays of dense projections or bars are in turn coincident with rings or chains of synaptic vesicles mobilized at release sites on the presynaptic membrane (having arrived at these precise points by microtubule translocation). Thus it is suggested that the presynaptic microtubules not only translocate synaptic vesicles, but because of their ordered arrays determine, in ontogeny, the ordered structure of the presynaptic grid.

The crystallization of thin-film ceramics

1992 ◽  
Vol 50 (1) ◽  
pp. 338-339
Author(s):  
J.M. Schwartz ◽  
L.F. Francis ◽  
L.D. Schmidt ◽  
P.S. Schabes-Retchkiman
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Sol Gel ◽  
Processing Route ◽  
Small Areas ◽  
Ceramic Thin Films ◽  
Complex Shapes ◽  
Sol Gel Process ◽  
Ceramic Precursors ◽  
Crystalline Ceramic

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.

Epitaxial Growth of Sr0.3Ba0.7Nb2O6 Thin Films Prepared by Sol-Gel Process

1999 ◽  
Vol 606 ◽  
Author(s):  
Keishi Nishio ◽  
Jirawat Thongrueng ◽  
Yuichi Watanabe ◽  
Toshio Tsuchiya
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Epitaxial Growth ◽  
Raw Materials ◽  
Substrate Surface ◽  
Sol Gel ◽  
Tungsten Bronze ◽  
Monomethyl Ether ◽  
Tetragonal Tungsten Bronze ◽  
Sol Gel Process

AbstructWe succeeded in the preparation of strontium-barium niobate (Sr0.3Ba0.7Nb2O6 : SBN30)that have a tetragonal tungsten bronze type structure thin films on SrTiO3 (100), STO, or La doped SrTiO3 (100), LSTO, single crystal substrates by a spin coating process. LSTO substrate can be used for electrode. A homogeneous coating solution was prepared with Sr and Ba acetates and Nb(OEt)5 as raw materials, and acetic acid and diethylene glycol monomethyl ether as solvents. The coating thin films were sintered at temperature from 700 to 1000°C for 10 min in air. It was confirmed that the thin films on STO substrate sintered above 700°C were in the epitaxial growth because the 16 diffraction spots were observed on the pole figure using (121) reflection. The <130> and <310> direction of the thin film on STO were oriented with the c-axis in parallel to the substrate surface. However, the diffraction spots of thin film on LSTO substrate sintered at 700°C were corresponds to the expected pattern for (110).

UV Curable Organic-Inorganic Hybrid Materials

2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang
Keyword(s):  
Hybrid Materials ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Solution Ph ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Degradation Temperature ◽  
Sol Gel Process ◽  
The Stability ◽  
Thermal Degradation Temperature

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥

Halogenation of ORMOSIL: A Promising Rout for Tailoring Optical Absorptions

2003 ◽  
Vol 771 ◽  
Author(s):  
Amir Fardad ◽  
Wei Liang ◽  
Yadong Zhang ◽  
Bryson Case ◽  
Shibin Jiang ◽  
...  
Keyword(s):  
Process Parameters ◽  
Sol Gel ◽  
Fiber Amplifiers ◽  
Grignard Reaction ◽  
Coupling Loss ◽  
Beam Splitters ◽  
Silicon Technology ◽  
Sol Gel Process ◽  
Propagation Losses ◽  
Signal Intensities

AbstractFluorinated and photo-imageable precursors are synthesized through a Barbier-Grignard reaction for 1550-nm window. The precursors are used for the sol-gel process of integrated optic components for silica-on-silicon technology. Material compositions and process parameters are optimized to achieve internal absorptions >0.1 dB/cm and propagation losses of about 0.5 dB/cm at 1550 nm. Compact 1×16 Beam splitters are designed and fabricated which exhibit >0.3 dB power uniformity, >0.1 dB PDL and 1.5 dB coupling loss. By hybrid integration of the passive splitters and in-house fiber amplifiers, amplifying splitters are demonstrated at various signal intensities.

Preparation and properties of a long time durable superhydrophilic titanium dioxide film obtained by a sol-gel process

2017 ◽  
Vol 59 (1) ◽  
pp. 81-85
Author(s):  
Jianjun Zhang ◽  
Hao Zeng ◽  
Chun Liu ◽  
Chao Li ◽  
Sude Ma ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Sol Gel ◽  
Titanium Dioxide Film ◽  
Sol Gel Process ◽  
Long Time ◽  
Dioxide Film
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