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Online since: April 2018
Authors: Michal Stanek, Martin Ovsik, Vojtech Senkerik
The cross-linking reaction, which predominates at high irradiation doses, results in the association of the polymer molecules into a network structure.
Radiation cross-linking creates changes in the PA6 structure by creating 3D net.
Beta radiation gradually penetrates more deeply into the PA6 structure through the surface layer.
Gehring, With Radiation Crosslinking of Engineering Plastics into the Next Millennium, Radiation Physics and Chemistry 57 (3) (2000), 361-365
Radiation Physics and Chemistry 97 (2014), 165-171
Radiation cross-linking creates changes in the PA6 structure by creating 3D net.
Beta radiation gradually penetrates more deeply into the PA6 structure through the surface layer.
Gehring, With Radiation Crosslinking of Engineering Plastics into the Next Millennium, Radiation Physics and Chemistry 57 (3) (2000), 361-365
Radiation Physics and Chemistry 97 (2014), 165-171
Online since: November 2015
Authors: Ulrike Schirmer, Andrea Osburg
Finger-Institute for Building Material Engineering, Chair of Building Chemistry and Polymer Materials, Coudraystraße 11 A, 99423 Weimar, Germany
aulrike.schirmer@uni-weimar.de, bandrea.osburg@uni-weimar.de
Keywords: cement, non-ionic stabilized polymer dispersions, particles, pore solution, attractive and repulsive forces, adsorption, zeta potential, turbidity
Abstract.
In partially hydrolyzed polyvinyl alcohol a small amount of acetyl group remains in structure.
(a) (b) Figure 2: Zeta potentials of the three model polymer dispersions in their original constitution (a); schematic layer structure of a PVOH stabilized polymer particle in water (b) Furthermore the dilution with pore solution of cement paste to a solid content of 20 %, which orientated on the ratio of water to polymer in a modified cement paste (w/c = 0.6 and p/c = 0.15) showed, that the presence of oppositely charged ions caused a charge reversal (Fig. 3).
(a) (b) Figure 3: Zeta potentials of the model polymer dispersions in cement paste pore solution (a); schematic layer structure of a PVOH stabilized polymer particle in cement paste pore solution (b) The effects of a stepwise titration of the two polyvinyl alcohols and the model polymer dispersions to cement suspensions (15 minutes after mixing) are shown in Figure 4.
[6] Ullmann´s Encyclopedia of Industrial Chemistry, A21 – Plastics, Properties and Testing of Polyvinyl Compounds, Wiley-VCH Verlag, Weinheim, 1992.
In partially hydrolyzed polyvinyl alcohol a small amount of acetyl group remains in structure.
(a) (b) Figure 2: Zeta potentials of the three model polymer dispersions in their original constitution (a); schematic layer structure of a PVOH stabilized polymer particle in water (b) Furthermore the dilution with pore solution of cement paste to a solid content of 20 %, which orientated on the ratio of water to polymer in a modified cement paste (w/c = 0.6 and p/c = 0.15) showed, that the presence of oppositely charged ions caused a charge reversal (Fig. 3).
(a) (b) Figure 3: Zeta potentials of the model polymer dispersions in cement paste pore solution (a); schematic layer structure of a PVOH stabilized polymer particle in cement paste pore solution (b) The effects of a stepwise titration of the two polyvinyl alcohols and the model polymer dispersions to cement suspensions (15 minutes after mixing) are shown in Figure 4.
[6] Ullmann´s Encyclopedia of Industrial Chemistry, A21 – Plastics, Properties and Testing of Polyvinyl Compounds, Wiley-VCH Verlag, Weinheim, 1992.
Online since: July 2017
Authors: Harald Rennhofer, Gerhard Sinn, Miriam M. Unterlass, Josef Wendrinsky, Helga C. Lichtenegger, Ursula Windberger, Gerald Singer
Lichtenegger1,g *
1 University of Natural Resources and Life Sciences Vienna, Institute of Physics and Material Sciences, Peter-Jordan-Straße 82, 1190 Vienna, Austria
2 Technische Universität Wien, Institute of Materials Chemistry,
Getreidemarkt 9/BC/02, 1060 Vienna, Austria
3 Medical University of Vienna, Division of Decentralized Biomedical Facilities,
Borschkegasse 8a, 1090 Vienna, Austria
agerald.singer@boku.ac.at, bharald.rennhofer@boku.ac.at, cgerhard.sinn@boku.ac.at, dmiriam.unterlass@tuwien.ac.at, ejosef.wendrinsky@aon.at, fursula.windberger@meduniwien.ac.at, ghelga.lichtenegger@boku.ac.at
Keywords: Carbon fiber reinforced polymer (CFRP), carbon nanotubes (CNT), dispersion, three-roll mill (TRM), high performance polymer, mechanical reinforcement, nanofiller, hierarchical composite
Abstract.
Carbon fiber reinforced polymers (CFRP) consist of high strength, high modulus carbon fibers with graphitic structure embedded in a polymer matrix.
However, CFRPs exhibit anisotropic properties due to the nature of fibers and their laminated structure.
Only extrusion and calendering are reported as non-destructive methods relating to the structure of dispersed CNTs and additionally both techniques can be used in industrial scale.
Galiotis, Carbon nanotube-polymer composites: Chemistry, processing, mechanical and electrical properties, Progress in Polymer Science 35 (2010) 357–401
Carbon fiber reinforced polymers (CFRP) consist of high strength, high modulus carbon fibers with graphitic structure embedded in a polymer matrix.
However, CFRPs exhibit anisotropic properties due to the nature of fibers and their laminated structure.
Only extrusion and calendering are reported as non-destructive methods relating to the structure of dispersed CNTs and additionally both techniques can be used in industrial scale.
Galiotis, Carbon nanotube-polymer composites: Chemistry, processing, mechanical and electrical properties, Progress in Polymer Science 35 (2010) 357–401
Online since: November 2011
Authors: Ke Fa Cen, Chong Du, Jun Hu Zhou, Jun Cheng, Lin Ye, Jian Zhong Liu, Yu Jie Yu
Cheng Jun [22-23] studied different effects on improving the CWS property made from Shenmu coal by employing microwave, thermal heat and pore fractal structures.
Effect of blending various coals on the properties of coal water slurry, Journal of Fuel Chemistry and Technology 2004,10 [8] Wu Guo-guang; Wang Xiao-chun; Liu Jiong-tian; Research on the ability of making slurry with NSF as additive for CWS and its effect, Journal of China University of Mining & Technology [J], 2005, 34(6): pp.703–706
Study of the matching performance between additive of coal water slurry and coal molecular structure.
Journal of Fuel Chemistry and Technology [J], 1996, 24(2): pp.174–180
Effects of pore fractal structures of ultrafine coal water slurries on rheological behaviors and combustion dynamics, Fuel 2008(87),pp.2620-2627
Effect of blending various coals on the properties of coal water slurry, Journal of Fuel Chemistry and Technology 2004,10 [8] Wu Guo-guang; Wang Xiao-chun; Liu Jiong-tian; Research on the ability of making slurry with NSF as additive for CWS and its effect, Journal of China University of Mining & Technology [J], 2005, 34(6): pp.703–706
Study of the matching performance between additive of coal water slurry and coal molecular structure.
Journal of Fuel Chemistry and Technology [J], 1996, 24(2): pp.174–180
Effects of pore fractal structures of ultrafine coal water slurries on rheological behaviors and combustion dynamics, Fuel 2008(87),pp.2620-2627
Online since: March 2015
Authors: Ning Wang, Teng Luo
Analysis of Carbon Emission Reduction Potential by Clean Coal Technology in China
Teng Luo1, Ning Wang2,*
1 Beijing Research Institute of Coal Chemistry, China Coal Research Institute, Beijing China
2 School of Environment, Tsinghua University, Beijing, China
* Corresponding author.
It is predicted that coal will continue to play a leading role in the energy structure of China for a long time [2].
In the current international context, where low carbon emissions are vigorously advocated, the coal-based energy consumption structure poses a severe challenge for realizing the goal of carbon emission reductions in China.
Sources: China Coal Transportation & Sale Society, China Electricity Council, and National Bureau of Statistics Fig. 2 China's coal consumption structure since 2000 Analysis shows that about 80% of coal in China is used for direct combustion, and the annual CO2 emissions account for 90% of the total amount of CO2 emissions.
(2) Steady development of modern coal chemical industry The modern coal chemical industry mainly produces clean energy and petroleum-based substitute oil, and forms a new integrated industry of “coal-oil-chemistry-electricity” combined with energy and chemical engineering technologies (see Fig. 3).
It is predicted that coal will continue to play a leading role in the energy structure of China for a long time [2].
In the current international context, where low carbon emissions are vigorously advocated, the coal-based energy consumption structure poses a severe challenge for realizing the goal of carbon emission reductions in China.
Sources: China Coal Transportation & Sale Society, China Electricity Council, and National Bureau of Statistics Fig. 2 China's coal consumption structure since 2000 Analysis shows that about 80% of coal in China is used for direct combustion, and the annual CO2 emissions account for 90% of the total amount of CO2 emissions.
(2) Steady development of modern coal chemical industry The modern coal chemical industry mainly produces clean energy and petroleum-based substitute oil, and forms a new integrated industry of “coal-oil-chemistry-electricity” combined with energy and chemical engineering technologies (see Fig. 3).
Online since: April 2015
Authors: Wen Tao Wang, Jian Huang, Bing Tao Tang, Jin Jing Qiu, Shu Fen Zhang
After treated with crosslinking agen, the crosslinking reaction took place between dye and dye, the polymeric web structure was formed on the PP, the dye was absorbed on surface of PP by van der Waal’s forces, see the Scheme 6.
The dyed PP was fast to soaping owing to polymeric web structure and van der Waal’s forces, but the dyed PP became almost white after rub fastness test,this clearly indicates that, during the dyeing and crosslinking-fixing process, the polymeric web structure and van der Waal’s forces could not just mechanically hold the crosslinking polymeric dye on the fiber.
Burkinshaw, A greener approach to cotton dyeings with excellent wash fastness, Green Chemistry, 4 (2002) 47-52
Witkamp, Excellent dye fixation on cotton dyed in supercritical carbon dioxide using fluorotriazine reactive dyes, Green Chemistry, 7 (2005) 609-616
The dyed PP was fast to soaping owing to polymeric web structure and van der Waal’s forces, but the dyed PP became almost white after rub fastness test,this clearly indicates that, during the dyeing and crosslinking-fixing process, the polymeric web structure and van der Waal’s forces could not just mechanically hold the crosslinking polymeric dye on the fiber.
Burkinshaw, A greener approach to cotton dyeings with excellent wash fastness, Green Chemistry, 4 (2002) 47-52
Witkamp, Excellent dye fixation on cotton dyed in supercritical carbon dioxide using fluorotriazine reactive dyes, Green Chemistry, 7 (2005) 609-616
Online since: November 2019
Authors: Hanan Alkazaali, Raad Sh. Alnayli
The structure, morphology, size, and hence properties of nanoparticles will differ for different media including solvent and surfactant [8].
Ag nanoparticle with polycrystalline structure was established by (JCPDS card No. 04-0783).
Which evidences the presence of implanted silver particles with fcc structure of their internal region in agreement with the EXAFS result.
Nanochemistry: A chemical approach to nanomaterials, The Royal Society of Chemistry, UK; pp v-ix, (2005)
Organic Chemistry 2nd.
Ag nanoparticle with polycrystalline structure was established by (JCPDS card No. 04-0783).
Which evidences the presence of implanted silver particles with fcc structure of their internal region in agreement with the EXAFS result.
Nanochemistry: A chemical approach to nanomaterials, The Royal Society of Chemistry, UK; pp v-ix, (2005)
Organic Chemistry 2nd.
Online since: June 2006
Authors: N. Al-Jufairi
Box 317 Doha / Qatar
E-mail, najlh2000@yahoo.com; naljufairi@qu.edu.qa
Keywords: Titania, Sol-gel, Nano-structure.
The coating films are always crystallined in the anatase structure with circular particles in nanometer size.
The structure of such materials can be defined by chemical means [2].
The statistics results indicate that films are always crystallined in anatase structure with circular particles in nanometer size.
Scherer: Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing, Academic Press, Inc.
The coating films are always crystallined in the anatase structure with circular particles in nanometer size.
The structure of such materials can be defined by chemical means [2].
The statistics results indicate that films are always crystallined in anatase structure with circular particles in nanometer size.
Scherer: Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing, Academic Press, Inc.
Online since: February 2013
Authors: Hong Yan Li, Yang Liu
Research Progress on the Extraction, Purification and Pharmacological Action of Flavonoids in Trollius Chinensis Bunge
Hongyan Lia,Yang Liub*
(School of chemical and pharmaceutical engineering, Jilin Institute of Chemical Technology, 45 Chengde road, Longtan District, 132022 Jilin, Republic of China)
aemail:lhylx521@126.com bemail: liuyang84@126.com
Keywords: Trollius Chinensis Bunge; flavonoids; pharmacological actions; progress
Abstract: Trollius Chinensis Bunge, a kind of Ranunculaceae plants, has been widely used in pharmacology, pharmaceutical chemistry, pharmacy and clinical.
The Structure and Distribution of the Flavonoids in Plants [J].Plant Research, 2000, 113: 287-299
The Structure and Distribution of the Flavonoids in Plants [J].Plant Research, 2000, 113: 287-299
Online since: May 2004
Authors: Bilge Saruhan, Uwe Schulz, Christoph Leyens
Magnetoplumbite structure through its interlocking grain morphology and unique
crystal structure provides essentially a sintering resistant, low thermal conductive layer, but also
imparts a catalytic layer to reduce the environmentally harmful substances produced during
propulsion and increase the catalytic performance.
Atmospheric chemistry of nitrogen oxides causing air pollution and acid rain [3] European norms for automobiles are sharpened enormously in the last five years.
Complex structure of these compounds makes it difficult to realize as coatings by conventional methods.
Results and Discussion La-Hexaluminates forms highly defective magnetoplumbite crystal structure.
Such a structure consists of [AlO16]+ spinel blocks intercalated by mirror planes of composition [LaAlO3]0.
Atmospheric chemistry of nitrogen oxides causing air pollution and acid rain [3] European norms for automobiles are sharpened enormously in the last five years.
Complex structure of these compounds makes it difficult to realize as coatings by conventional methods.
Results and Discussion La-Hexaluminates forms highly defective magnetoplumbite crystal structure.
Such a structure consists of [AlO16]+ spinel blocks intercalated by mirror planes of composition [LaAlO3]0.