Cyanate Ester Resin/Silica subnanocomposites and their superiority over nanocomposites due to fundamental role of constrained interfacial dynamics

Abstract The study of nanostructure, thermal and relaxation properties (by HAADF-STEM, EDXS, DMA and DSC), combined with the calculations of interparticle distances and interfacial areas, has been performed for a series of the hybrid Cyanate Ester Resin (CER)/Si02 polymer composites with 0.01 to 10 wt.% Si02 units introduced via a sol-gel process. The absence of clusterization, arising only subnanometric Si02 nodes and their quasi-regular distribution within the amorphous matrix, with the shortest distances between nodes, provided their exceptional positive impact on the matrix properties at ultra-low Si02 contents of 0.03-0.1 wt.%. The superiority of these subnanocomposites over the nanocomposites was determined by the role of constrained interfacial dynamics over the whole matrix.

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Sol-Gel Process form Heterometallic Alkoxides to Incorporate Alkaline- and Rare Earths in Alumina for automotive Applications

MRS Proceedings ◽

10.1557/proc-431-331 ◽

1996 ◽

Vol 431 ◽

Author(s):

C. K. Narula

Keyword(s):

Elevated Temperatures ◽

Sol Gel ◽

Automotive Applications ◽

Automotive Catalysts ◽

Heterometallic Alkoxides ◽

Sol Gel Process ◽

Alkaline Earths ◽

Cost Of Materials ◽

Gel Processing

AbstractThe high cost of materials prepared by sol-gel processing and the loss of useful surface properties at elevated temperature has prevented the application of sol-gel processed materials in automotive exhaust reduction catalyst formulations. In this report, we briefly describe the important developments needed in the next generation automotive catalysts and the role of sol-gel processed materials. We will also discuss the application of heterometallic alkoxides as sol-gel precursors to achieve the molecular distribution of lanthanides and alkaline earths in alumina matrices needed for the stabilization of alumina based materials at elevated temperatures.

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Synthesis and characterization of benzoxazine resin-SiO2 hybrids by sol-gel process: The role of benzoxazine-functional silane coupling agent

Polymer ◽

10.1016/j.polymer.2011.04.044 ◽

2011 ◽

Vol 52 (13) ◽

pp. 2757-2763 ◽

Cited By ~ 39

Author(s):

Tarek Agag ◽

Tsutomu Takeichi

Keyword(s):

Coupling Agent ◽

Silane Coupling Agent ◽

Sol Gel ◽

Synthesis And Characterization ◽

Sol Gel Process ◽

Silane Coupling

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Leaching Behavior of Edta In A Silica Sol-Gel Matrix

MRS Proceedings ◽

10.1557/proc-346-323 ◽

1994 ◽

Vol 346 ◽

Cited By ~ 1

Author(s):

Kris S. Oka ◽

J.D. Mackenzie

Keyword(s):

Pore Volume ◽

Sol Gel ◽

Silica Matrix ◽

Silica Gels ◽

Volume Distribution ◽

Leaching Behavior ◽

Sol Gel Process ◽

The Matrix ◽

Physical Changes ◽

Hydrolysis Of

ABSTRACTEthylene diamine tetra-acetic acid (EDTA) doped silica gels were made by the sol-gel process for the potential application as a filter for heavy metal ions in wastewater. The behavior of the organic molecule in the matrix was studied by investigating the percentage of EDTA leached out with a variation in the timing of addition of the EDTA molecule into the starting silica gel solution. Leach tests using water as the medium were performed for 2, 12 and 24 hours in order to determine the amount of EDTA trapped in the pores or in the matrix. A minimum amount of EDTA leached from the gels was detected in the samples to which EDTA was added 4 hours after initial hydrolysis of TEOS. This result was correlated to having a greater percentage of pore volume in the range of 15–20 Å, which was further substantiated with density measurements. The physical changes in the silica matrix altering the pore volume distribution were attributed to the addition of the water into which the EDTA molecule was initially dissolved.

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Drug Loaded Porous Hydroxyapatite and Its In Vitro Release

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.284-286.423 ◽

2005 ◽

Vol 284-286 ◽

pp. 423-426 ◽

Cited By ~ 2

Author(s):

Y. Kim ◽

B.G. Song ◽

Soo Ryong Kim ◽

Kwang Jin Kim

Keyword(s):

Mesoporous Silica ◽

Body Fluid ◽

Sol Gel ◽

In Vitro Release ◽

Controlled Drug Delivery ◽

Porous Hydroxyapatite ◽

Sol Gel Process ◽

The Matrix ◽

Vitro Release

Porous hydroxyapatite coated with mesoporous silica has been utilized as the matrix for controlled drug delivery. TEM observation confirms the pore size of mesoporous silica scatters about 50 Å. Porous hydroxyapatite was coated with mesoporous silica via sol-gel process. Ibuprofen and was loaded into the pores of mesoporous silica, and controlled release profiles were studied by soaking the samples in a simulated body fluid using a UV-VIS spectrophotometer.

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The role of uranium(VI) in the ThO2UO3 SolGel process

Journal of Colloid and Interface Science ◽

10.1016/0021-9797(80)90503-2 ◽

1980 ◽

Vol 78 (1) ◽

pp. 155-162 ◽

Cited By ~ 1

Author(s):

Param H Tewari ◽

Allan B Campbell

Keyword(s):

Sol Gel ◽

Sol Gel Process

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Sol-gel Elaboration of Porous Oxide Coatings as Interphase in SiC/SiC Ceramic Matrix Composites

MRS Proceedings ◽

10.1557/proc-775-p3.24 ◽

2003 ◽

Vol 775 ◽

Author(s):

M. Verdenelli ◽

S. Parola ◽

F. Chassagneux ◽

S. Jacques ◽

H. Vincent ◽

...

Keyword(s):

Electron Microscopy ◽

Sol Gel ◽

Ceramic Matrix Composites ◽

Matrix Composites ◽

X Ray Diffraction ◽

Brittle Behavior ◽

Transmission Electron ◽

Sol Gel Process ◽

The Matrix ◽

Mesoporous Oxide

AbstractCombinations of meso-, macro- and microporous coatings with a chemical composition of 90%Al2O3-10%SiO2 were elaborated on SiC Hi-Nicalon fibers using the sol-gel process. They were evaluated as porous interphase for the reinforcement of CMC. The mesoporous oxide, in contact with the fiber, allows cracks deviation whereas the macroporous one, in contact with the matrix, avoids the gaseous infiltration of the mesopores during the SiC CVD matrix process. It also prevents from oxygen diffusion during high temperature under air. The characterization of the composites was performed by SEM (scanning electron microscopy), TEM (transmission electron microscopy), X-ray diffraction, and EDS (energy dispersive spectrometry). TEM evidenced the porosity gradient as expected. A tensile test on the composites revealed brittle behavior (fracture) and no fiber debonding was observed.

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Dual role of the reactant MOH (M=Li, Na or K) in the growth of ZnO quantum dots under a sol–gel process: promoter and inhibitor

RSC Advances ◽

10.1039/c6ra06660g ◽

2016 ◽

Vol 6 (55) ◽

pp. 50173-50179 ◽

Cited By ~ 2

Author(s):

Song Li ◽

Song Ye ◽

Tianhua Liu ◽

Zhuang Guo ◽

Huiyun Wang ◽

...

Keyword(s):

Quantum Dots ◽

Sol Gel ◽

Dual Role ◽

Synthesis Process ◽

Sol Gel Process ◽

Zno Quantum Dots ◽

Sol Gel Synthesis

ZnO quantum dots (QDs) with tunable size and photoluminescence can be achieved simply by controlling their growth during the sol–gel synthesis process.

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Two-photon controlled sol–gel condensation for the microfabrication of silica based microstructures. The role of photoacids and photobases

RSC Advances ◽

10.1039/c7ra08608c ◽

2017 ◽

Vol 7 (74) ◽

pp. 46615-46620 ◽

Cited By ~ 4

Author(s):

J. Kustra ◽

E. Martin ◽

D. Chateau ◽

F. Lerouge ◽

C. Monnereau ◽

...

Keyword(s):

Laser Beam ◽

Focal Point ◽

Sol Gel ◽

Ph Changes ◽

Two Photon ◽

Photon Excitation ◽

Sol Gel Process ◽

And Control ◽

Two Photon Excitation

Two-photon excitation of photobases is used to induce pH changes and control the condensation step of the sol–gel process at the focal point of a laser beam in a confocal configuration.

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Sol–Gel Encapsulation of ZnAl Alloy Powder with Alumina Shell

Coatings ◽

10.3390/coatings11111389 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1389

Author(s):

David Svetlizky ◽

Noam Eliaz

Keyword(s):

Sol Gel ◽

Self Healing ◽

Matrix Composites ◽

Self Assembled Monolayer ◽

Air Atmosphere ◽

Custom Made ◽

Sol Gel Process ◽

The Matrix ◽

Core Powder ◽

Directed Energy

Additive manufacturing (AM), for example, directed energy deposition (DED), may allow the processing of self-healing metal–matrix composites (SHMMCs). The sealing of cracks in these SHMMCs would be achieved via the melting of micro-encapsulated low melting point particulates (LMPPs), incorporated into the material during AM, by heat treatment of the part during service. Zn-Al alloys are good candidates to serve as LMPPs, for example, when the matrix of the MMC is made of an aluminum alloy. However, such powders should first be encapsulated by a thermal and diffusion barrier. Here, we propose a sol–gel process for encapsulation of a custom-made ZA-8 (Zn92Al8, wt.%) core powder in a ceramic alumina (Al2O3) shell. We first modify the surface of the ZA-8 powder with (12-phosphonododecyl)phosphonic acid (Di-PA) hydrophobic self-assembled monolayer (SAM) in order to prevent extensive hydrogen evolution and formation of non-uniform and porous oxide/hydroxide surface layers during the sol–gel process. Calcination for 1 h at 500 °C is found to be insufficient for complete boehmite-to-γ(Al2O3) phase transformation. Thermal stability tests in an air-atmosphere furnace at 600 °C for 1 h result in melting, distortion, and sintering into a brittle sponge (aggregate) of the as-atomized powder. In contrast, the core/shell powder is not sintered and preserves its spherical morphology, with no apparent “leaks” of the ZA-8 core alloy out of the ceramic encapsulation.

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