Physical-Chemical Properties of TiO2 Membranes Controlled By Sol-Gel Processing

1988 ◽  
Vol 132 ◽  
Author(s):  
Qunyin Xu ◽  
Marc A. Anderson
Keyword(s):  
Primary Particle ◽  
Sol Gel ◽  
Chemical Properties ◽  
Primary Particle Size ◽  
Chemical Processes ◽  
Gel Structure ◽  
Physical Chemical ◽  
Membrane Porosity ◽  
Gel Processing ◽  
Alkoxide Precursors

ABSTRACTParticulate TiO2 membranes have been prepared by sol-gel techniques from alkoxide precursors. The degree of aggregation, which is controlled by physical chemical processes during sol preparation influences the gelling volume and gel structure. While three types of gel structures have been proposed, the porosity of the final membrane seems to be little affected by these hydrogel structures. Firing temperature is a much more critical parameter. It is concluded that the primary particle size determines the final membrane porosity in this TiO2 system.

Sol-gel processing of PbTiO3 and Pb(Zr0.52Ti0.48)O3 fibers

1992 ◽  
Vol 7 (4) ◽  
pp. 992-996 ◽  
Author(s):  
Ulagaraj Selvaraj ◽  
A.V. Prasadarao ◽  
Sridhar Komarneni ◽  
Keith Brooks ◽  
Stewart Kurtz
Keyword(s):  
Heat Treatment ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Heat Treated ◽  
Viscous Solutions ◽  
Gel Processing ◽  
Alkoxide Precursors

Homogeneous and stoichiometric PbTiO3 and PbZr0.52Ti0.48O3 gel fibers were drawn from viscous solutions prepared by sol-gel processing of alkoxide precursors. The fibrous gels on heating at 450 and 600 °C, respectively, formed the well-crystallized phases of PbTiO3 and PbZr0.52Ti0.48O3. Fibers heat treated at 700 °C are a few centimeters long and 50 to 150 μm in diameter. PbZr0.52Ti0.48O3 fibers subjected to heat treatment at 700 °C for 1 h consisted of fully dense submicron grains (0.15 to 0.2 μm). However, PbTiO3 fibers under analogous conditions showed a few micropores with grains of ∼0.1 μm. Dielectric constants of these PbTiO3 and PbZr0.52Ti0.48O3 fibers were approximately 300 and 800, respectively.

Preparation and Properties of Porous Apatite-Wollastonite Bioactive Glass-Ceramic

2007 ◽  
Vol 330-332 ◽  
pp. 169-172 ◽  
Author(s):  
Ming Xue ◽  
Jun Ou ◽  
Da Li Zhou ◽  
Dange Feng ◽  
Wei Zhong Yang ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Stromal Cells ◽  
Glass Ceramic ◽  
Sol Gel ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Polymer Foam ◽  
Physical Chemical ◽  
Sol Gel Process ◽  
Precursor Powders

The porous apatite-wollastonite bioactive glass-ceramic (AW-GG) was made from nano-precursor powders derived from sol-gel process, and shaped by dipping method with polymer foam. The physical-chemical properties, bioactivity and biocompatibility of the materials were studied by means of TG, XRD, SEM, TEM and so on. The bioactivity was investigated in simulated body fluid (SBF) and the biocompatibility was evaluated by co-culturing with marrow stromal cells (MSCs). The result shows that: the particle size of the AW precursor powders is 40~100nm; porous AW GC has three-dimensional pored structure with 300~500um macropores and 2~5um micropores; the materials possess high bioactivity and biocompatibility. Porous AW GC may therefore have great potential application as bone tissue engineering scaffold.

Inorganic-organic Hybrid Materials (ORMOCERs) for Multilayer Technology – Passivation and Dielectric Behavior

2001 ◽  
Vol 665 ◽  
Author(s):  
R. Houbertz ◽  
L. Fröhlich ◽  
J. Schulz ◽  
M. Popall
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Dielectric Behavior ◽  
Good Resolution ◽  
Physical And Chemical Properties ◽  
Coating Technology ◽  
Organic Hybrid ◽  
Physical And Chemical ◽  
Gel Processing ◽  
And Chemical Properties

ABSTRACTInorganic-organic hybrid polymers (ORMOCER®s) have been synthesized by sol-gel processing. The materials can be functionalized such that their physical and chemical properties can be reproducibly tailored towards the desired application, i.e., electronics, optics (passives/actives) or passivation technology. Besides, the materials which show negative resist behavior, can be patterned by UV exposure with good resolution. The materials are well-suited for thin and thick film technology using conventional coating technology, applied in multi-layer technology. We here particularly focus on materials for passivation against environmental influences, which additionally exhibit very good dielectric properties.

scholarly journals Development of resin-based bioactive endodontic cements with glycerol salicylate and calcium silicate

2020 ◽  
Vol 61 (1) ◽  
pp. 69-76
Author(s):  
Rafaela Cassaro Pistorello ◽  
Gabriela De Souza Balbinot ◽  
Vicente Castelo Branco Leitune ◽  
Fabricio Mezzomo Collares
Keyword(s):  
Calcium Silicate ◽  
Methyl Salicylate ◽  
Setting Time ◽  
Sol Gel ◽  
Chemical Properties ◽  
Distilled Water ◽  
Physical Chemical ◽  
Time Flow

Introduction: The combination of sol-gel derived calcium silicate particles and glycerol salicylate resins may enhance the pyhisico-chemical properties contribute to the understanding of the interaction between these materials. This study aims to evaluate the physical-chemical properties of resin-based bioactive endodontic cements with glycerol salicylate resins and calcium silicate particles. Materials and methods: Calcium silicate was produced by the sol-gel route, while the resin was produced by mixing 60wt% glycerol salicylate, 30wt% methyl salicylate and 10wt% distilled water. Calcium silicate was added in three different concentrations, 50, 40 and 25% by weight. The cement was tested for setting time, flow, radiopacity and pH. Results: The 50:50 group shows the time of 15min8s while the 75:25 shows the time of 256min13s (p

Crystallization of barium titanate thin films synthesized via sol-gel processing

1995 ◽  
Vol 53 ◽  
pp. 258-259
Author(s):  
M. C. Gust ◽  
N. D. Evans ◽  
M. L. Mecartney
Keyword(s):  
Thin Films ◽  
Barium Titanate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Independent Films ◽  
X Ray ◽  
Fine Grained ◽  
Diffraction Patterns ◽  
Gel Processing ◽  
Alkoxide Precursors

Sol-gel processing of oxide thin films offers the potential to generate different microstructures by varying process parameters such as water of hydrolysis, chemical precursor, or substrate. For this work, barium titanate (BaTiO3) thin films were prepared by the sol-gel method in order to try and generate different microstructures for dielectric measurements. However, for BaTiOs prepared using alkoxide precursors, the final microstructures of the films were found to be almost process independent. Films using different precursors, different substrates, and different amounts of water of hydrolysis all showed similar TEM microstructures. All the films after final heat treatment were polycrystalline, nanoporous, and randomly oriented BaTiO3; they were also fine-grained, with an average uniform grain size of 25-50 nm (Fig. 1). This fine-grained microstructure has also been observed in other studies of sol-gel derived BaTiO3 thin films. In addition to BaTiO3, electron diffraction patterns showed the presence of trace amounts of rutile TiO2 that were not observed by x-ray diffraction (XRD).

New insight in the role of modifying ligands in the sol-gel processing of metal alkoxide precursors: A possibility to approach new classes of materials

2006 ◽  
Vol 40 (2-3) ◽  
pp. 163-179 ◽  
Author(s):  
Vadim G. Kessler ◽  
Gerald I. Spijksma ◽  
Gulaim A. Seisenbaeva ◽  
Sebastian Håkansson ◽  
Dave H. A. Blank ◽  
...  
Keyword(s):  
Sol Gel ◽  
Metal Alkoxide ◽  
Gel Processing ◽  
Alkoxide Precursors

scholarly journals Grinding efficiency increase through physical – chemical processes control in “tool-billet” contact

2016 ◽  
Vol 1 (5) ◽  
pp. 24-29
Author(s):  
Борис Бржозовский ◽  
Boris Brzhozovskiy ◽  
Андрей Славин ◽  
Andrey Slavin
Keyword(s):  
Process Control ◽  
Chemical Process ◽  
Chemical Properties ◽  
Chemical Processes ◽  
Grinding Process ◽  
Physical Chemical ◽  
Efficiency Increase ◽  
Grinding Efficiency ◽  
The Impact ◽  
Chemical Process Control

The ways to increase grinding effectiveness by means of physical –chemical process control in a “disk-billet” contact are considered. The impact of physical-chemical properties of cutting emulsion (CE) upon grinding basic indices is shown. The hierarchical threshold structure of a grinding process based on a neuronet model allowing automating the machining techniques designing is offered.

New Chemistry for the Sol-Gel Process: Acetone as a New Condensation Reagent

1992 ◽  
Vol 271 ◽  
Author(s):  
Subhash C. Goel ◽  
Michael Y. Chiang ◽  
Patrick C. Gibbons ◽  
William E. Buhro
Keyword(s):  
Aldol Condensation ◽  
Sol Gel ◽  
Metal Alkoxide ◽  
Sol Gel Process ◽  
New Process ◽  
Gel Processing ◽  
Alkoxide Precursors

ABSTRACTA nonhydrolytic sol-gel process that uses acetone as the condensation reagent is described. In the new process, the hydrocarbon soluble Zn(OCEt3)2 is converted to a rigid, transparent gel and then to ZnO by an aldol-condensation-elimination sequence. The chemical pathway for the transformation has been established, and differs completely from the pathway for the conventional hydrolytic sol-gel processing of alkoxide precursors. The new, nonhydrolytic strategy may prove applicable to a variety of metal-alkoxide systems.

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