Control of Hierarchically Ordered Positive and Negative Replicas of Wood Cellular Structures by Surfactant-Directed Sol-Gel Mineralization

2002 ◽  
Vol 726 ◽  
Author(s):  
Yongsoon Shin ◽  
Jun Liu ◽  
Li-Qiong Wang ◽  
Jeong Ho Chang ◽  
William D. Samuels ◽  
...  
Keyword(s):  
Silicic Acid ◽  
Cell Walls ◽  
Cellular Structure ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Silica Particles ◽  
Low Ph ◽  
Cellular Structures ◽  
Inner Surface

AbstractWe here report the synthesis of ordered ceramic materials with hierarchy produced by an in-situ mineralization of ordered wood cellular structures with surfactant-templated sol-gel at different pH. At low pH, a silicic acid is coated onto inner surface of wood cellular structure and it penetrates into pores left, where degraded lignin and hemicellulose are leached out, to form a positive replica, while at high pH the precipitating silica particles due to fast condensation clog the cells and pit structures to form a negative replica of wood. The calcined monoliths produced in different pHs contain ordered wood cellular structures, multi-layered cell walls, pits, vessels well-preserved with positive or negative contrasts, respectively. The surfactant-templated mineralization produces ordered hexagonal nanopores with 20Å in the cell walls after calcination.

Silica and Silane Coupling Agent for in Situ Reinforcement of Acrylonitrile-Butadiene Rubber

1999 ◽  
Vol 72 (1) ◽  
pp. 119-129 ◽  
Author(s):  
K. Murakami ◽  
S. Osanai ◽  
M. Shigekuni ◽  
S. Iio ◽  
H. Tanahashi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Silica Particles ◽  
Butadiene Rubber ◽  
Acrylonitrile Butadiene Rubber ◽  
In Situ Silica ◽  
Transmission Electron ◽  
Dispersion Agent ◽  
The Relationship

Abstract In situ silica reinforcement for the acrylonitrile-butadiene rubber (NBR) vulcanizates, which were premixed with a conventional silica (VN-3) and γ-mercaptopropyltrimethoxysilane (γ-MPS), was achieved by the sol-gel reaction of tetraethoxysilane (TEOS) using ethylenediamine. It was observed that the reinforcement efficiency tended to increase with the increase of mechanically premixed conventional silica. From the observations of transmission electron microscopy and scanning electron microscopy, the simultaneous use of VN-3 and γ-MPS was found to promote the formation of large silica particles and clusters with a relatively good dispersion by the sol-gel reaction of TEOS in the NBR vulcanizate. The results of hysteresis measurements supported this promotion. It was considered to be due to the surface modification of VN-3 by the sol-gel reaction of TEOS and the presence of γ-MPS which worked as a dispersion agent for silica particles. The relationship between the mechanical properties and the morphology of the in situ silica filled vulcanizates is discussed.

In situ formed silica particles in rubber vulcanizate by the sol-gel method

Polymer ◽  
1997 ◽  
Vol 38 (17) ◽  
pp. 4417-4423 ◽  
Author(s):  
Yuko Ikeda ◽  
Shinzo Kohjiya
Keyword(s):  
Sol Gel ◽  
Silica Particles ◽  
Gel Method ◽  
Sol Gel Method ◽  
Rubber Vulcanizate

Fabrication of teardrop-shaped silica particles in polyelectrolyte diluted solution through in situ sol–gel process

2011 ◽  
Vol 58 (3) ◽  
pp. 651-655 ◽  
Author(s):  
LinYong Song ◽  
ChunLei Lin ◽  
Lan Wang ◽  
HaiLin Sheng ◽  
YiFeng Zhou ◽  
...  
Keyword(s):  
Sol Gel ◽  
Silica Particles ◽  
Sol Gel Process ◽  
Diluted Solution

Improvement of mechanical performance of solution styrene butadiene rubber by controlling the concentration and the size of in situ derived sol–gel silica particles

RSC Advances ◽  
2016 ◽  
Vol 6 (40) ◽  
pp. 33643-33655 ◽  
Author(s):  
V. Sankar Raman ◽  
A. Das ◽  
K. W. Stöckelhuber ◽  
S. B. Eshwaran ◽  
J. Chanda ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Sol Gel ◽  
Silica Particles ◽  
Polymer Chains ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Styrene Butadiene ◽  
Elastomeric Composites ◽  
Alkoxide Route

The silica particles generated from alkoxide route are grown onto the styrene butadiene polymer chains and offer a direct rubber to filler interaction. As a result, superior mechanical performance of the elastomeric composites can be realised.

In Situ Filling of Silica onto “Green” Natural Rubber by the Sol—Gel Process

2001 ◽  
Vol 74 (1) ◽  
pp. 16-27 ◽  
Author(s):  
S. Kohjiya ◽  
K. Murakami ◽  
S. Iio ◽  
T. Tanahashi ◽  
Y. Ikeda
Keyword(s):  
Natural Rubber ◽  
Silica Surface ◽  
Sol Gel ◽  
Renewable Resource ◽  
Crosslinking Density ◽  
Silica Particles ◽  
Rubber Matrix ◽  
In Situ Silica ◽  
Silica Composite

Abstract The sol—gel reaction of tetraethoxysilane produced the fine and well-dispersed in situ silica particles in the “green” natural rubber (NR) matrix before curing. This new method was developed for a NR/silica composite material, and a good reinforcement effect of in situ silica was observed on the NR vulcanizate. The method is expected to be an industrially practical technique. The in situ silica did not much inhibit the accelerated sulfur curing. Thus, it is estimated that the concentration of silanol groups on the in situ silica surface was smaller than those on the conventional silica surface. The silica—silica interaction of in situ silica seems to be weaker to result in better dispersion in the rubber matrix compared with the conventional silica. Atomic force microscopy suggested that the wettability of NR onto in situ silica was higher than that onto conventional silica. The hardness, modulus at 50% elongation and the storage modulus at room temperature of in situ silica-filled NR vulcanizate were smaller than those of conventional silica-filled NR vulcanizate, although the crosslinking density of the former was larger than that of the latter and their silica contents were comparable. These unique characteristics of in situ silica-filled vulcanizate seem to be ascribed to the fine and well-dispersed in situ silica particles in the NR matrix. These observations suggest that NR (a renewable resource)/in situ silica composite has much potential as an ecologically “green” material in the rubber industry.

Durability of Wood-PMMA Composite

2010 ◽  
Vol 26-28 ◽  
pp. 830-834 ◽  
Author(s):  
Jian Li ◽  
Yong Feng Li ◽  
Xin Meng ◽  
Yi Xing Liu
Keyword(s):  
Cell Walls ◽  
Cellular Structure ◽  
In Situ Polymerization ◽  
Untreated Wood ◽  
Acid Resistance ◽  
Water Repellency ◽  
Decay Resistance ◽  
Chemical Combination ◽  
Pmma Polymer

Wood-PMMA composite was manufactured by impregnating methyl methacralyte (MMA) monomers into wood porous structure, followed by in-situ polymerization through catalyst-thermal treatment. The structure was simply analyzed by SEM and FTIR, and its durability was also examined. The results indicate that PMMA polymer generated in wood cellular structure, and interacted with wood cell walls, resulting in chemical combination between them. The durability involving dimensional stability, water repellency, decay resistance as well as acid resistance was whole improved over untreated wood. Such composite enhancing wood values can be used as structural furniture material and traffic material.

Synthesis of TEOS-Based Silica Spherical Particles by Sol-Gel Process

2013 ◽  
Vol 773 ◽  
pp. 606-610
Author(s):  
Jing Li ◽  
Hong Qi Zhang ◽  
Wei Xue
Keyword(s):  
Sol Gel ◽  
Silica Particles ◽  
Electron Cloud ◽  
Polymerization Rate ◽  
Spherical Particles ◽  
Condensation Polymerization ◽  
Spherical Silica ◽  
Sol Gel Process ◽  
Spherical Silica Particles

Spherical silica particles, with mean sizes about 1.2 μm, were prepared through TEOS sol-gel process catalyzed by ammonia. The silica particles have a smooth surface and a small specific surface area, 3.4 m2/g. The sol-gel process was monitored by React IRTMusing an in-situ technique. Based on the measurements, mechanism of TEOS hydrolyzation and succedent condensation polymerization was inferred. With the adding of ammonia, OH-anion attacks Si atomic nucleus directly and makes it showing negative electricity. Therefore the electron cloud shifts to the OR group on the other side. This weakens the Si-O bond and results in the removal of the OR group. Furthermore, silanol, generated from TEOS hydrolyzation, attracts Si-OR or other Si-OH around; thereby resulting rapid dehydration or dealcohol between molecular. So the condensation polymerization rate is elevated, and Si-O-Si bond comes into being. Lastly, cross-linking reaction among Si-O-Si bonds forms the particle.

In-Situ Study of NiO Growth on Textured Nickel Tape Using Environmental Scanning Electron Microscope (ESEM) and Hot Stage

2001 ◽  
Vol 7 (S2) ◽  
pp. 1276-1277
Author(s):  
Y. Akin ◽  
R.E. Goddard ◽  
W. Sigmund ◽  
Y.S. Hascicek
Keyword(s):  
Buffer Layer ◽  
Lattice Mismatch ◽  
Sol Gel ◽  
Surface Oxidation ◽  
Dip Coating ◽  
Buffer Layers ◽  
Superconducting Film ◽  
Environmental Scanning ◽  
Cold Rolling And Annealing

Deposition of highly textured ReBa2Cu3O7−δ (RBCO) films on metallic substrates requires a buffer layer to prevent chemical reactions, reduce lattice mismatch between metallic substrate and superconducting film layer, and to prevent diffusion of metal atoms into the superconductor film. Nickel tapes are bi-axially textured by cold rolling and annealing at appropriate temperature (RABiTS) for epitaxial growth of YBa2Cu3O7−δ (YBCO) films. As buffer layers, several oxide thin films and then YBCO were coated on bi-axially textured nickel tapes by dip coating sol-gel process. Biaxially oriented NiO on the cube-textured nickel tape by a process named Surface-Oxidation- Epitaxy (SEO) has been introduced as an alternative buffer layer. in this work we have studied in situ growth of nickel oxide by ESEM and hot stage.Representative cold rolled nickel tape (99.999%) was annealed in an electric furnace under 4% hydrogen-96% argon gas mixture at 1050°C to get bi-axially textured nickel tape.

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