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Volume 45, Issue 4
Displaying 1-5 of 5 articles from this issue
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Influence of Oxidation, Reduction and Surfactants to Dispersibility of Carbon BlackToshihide KUWAHARA, Seishirô ITO1972 Volume 45 Issue 4 Pages 181-188
Published: April 30, 1972
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSThe purpose of this paper is to investigate about the changes of the surface properties (specific gravity, surface area, pH and functional group such as carboxyl group on the surface) by oxidation and reduction of carbon blacks, and also about the influence of these surface treatments and addition of various surfactants to the dispersibility of carbon blacks in water. Measurements are made about the sedimentation volume, _??_- potential and adsorption in various conditions and the following results are obtained :
1) Oxidation of carbon black by nitric acid increases the amount of specific gravity, surface area and carboxyl group, and decreases the pH value. However, reduction of carbon black by lithium aluminum hydride, gives quite reverse results.
2) It was found that the oxidation of carbon black causes nice dispersion in pure water, but reduction of carbon black of furnace type results in floatation on water.
3) The best dispersion state of all carbon blacks was obtained by addition of anionic surfactant.
4) The amount of adsorption of surfactant on carbon black was influenced by the kind and amount of functional groups on the surface of carbon blacks.View full abstractDownload PDF (1020K) -
“Jack-in-the-Box” EffectKatsuo AKAGANE, G.G. ALLAN1972 Volume 45 Issue 4 Pages 189-193
Published: April 30, 1972
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSCellulose pulp fibers are multilamellar and contain pores which range in size from 4 to 300Å. Futhermore, polyelectrolytes can develop charges within the macromolecules when subjected to pH changes in their environments.
It follows that if cellulose fibers, impregnated with a solution of polyelectrolyte, such as polyethyleneimine (PEI) at a given pH value, are washed at a lower pH, a sudden increase in the dimensions of the PEI macromolecules will occur as the pH of their environment decreases. As a result of this expansion, some of the macromolecules within the fibers will become greater in size than their containing pore.
They will be “irreversibly” stuck within these pores like a compressed “jack-in-the-box” until they are released by a suitable change in the environmental pH controlling their molecular size.
If the polymers have colors, the fibers can be spontaneously dyed as the polymers are adsorbed. Therefore, a protein was converted to the dye polymer by treating with a reactive dye. Thus, α-cellulose pulp fibers, impregnated with an aqueous solution of dye polymer gave maximum adsorption of the polymer at its isoelectric point because the protein macromolecule was in its smallest form at this pH. Conversly washed with water which has been adjusted to different pH values, maximum dye polymer elution was secured at the isoelectric point.View full abstractDownload PDF (533K) -
Hiroyuki SAIJYO1972 Volume 45 Issue 4 Pages 194-200
Published: April 30, 1972
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (1073K) -
Minoru IWAO1972 Volume 45 Issue 4 Pages 201-213
Published: April 30, 1972
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (1693K) -
Toshihiro MURAYAMA1972 Volume 45 Issue 4 Pages 214-226
Published: April 30, 1972
Released on J-STAGE: November 20, 2012
JOURNAL FREE ACCESSDownload PDF (3213K)
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