1987 Fiscal Year Final Research Report Summary
Studies on the mechanism for the specific adsorption of metal ions by chitin derivatives
| Project/Area Number |
61460210
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
高分子物性
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| Research Institution | Hokkaido University |
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Principal Investigator |
IZUMI Yosahinobu Faculty of Science, Hokkaido University, 理学部, 助手 (30002158)
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| Co-Investigator(Kenkyū-buntansha) |
KANEKO Motozo Faculty of Science, Hokkaido University, 理学部, 名誉教授 (10000720)
TOKURA Seiichi Faculty of Science, Hokkaido University, 理学部, 教授 (40000806)
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| Project Period (FY) |
1986 – 1987
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| Keywords | CM-chitin / Effect of CM-chitin concentration / Effext of salt / Dynamic light scattering / X-ray small-angle scattering / Gelation / Polyelectrolyte solution / EXAFS |
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| Research Abstract |
1. Dynamic light scattering measurements were performed to clarify the action of chitintoward Ca ion through the difference between the effect of Ca ion and that of Na ion on the conformation of CM-chition molecule and through the compatison of the effect of salt on CM-chitin molecule with that on CM-cellulose whose structure resembles that of chitin. It is shown that there is no difference between the action of Ca ion and that of Na ion at least in the semi-dilute solution
2. X-ray small-angle scattering measurements were performed to clarify the adsorption mechanism of metal ions toward CM-chitin in the semi-dilute solution. We examined the q dependence of the scattering Law S(q) and its variation with the concentration of CM-chitin and addition of salt. It is show that the effects of CM-chitin and in salt concentration screen the Coulomb interactions and modify the structure of the solutions but there is a strong difference in the q dependence. The variation of concentration has a considerable effect on the correlation length whereas the addition of salt has an inverse effect on it. The former behavior agrees with the theoretical prediction whereas the latter does not agree. The disagerrment is explained in terms of the correlation length in the short range. The addition of ferric ions in CM-chitin solution showed a drastic effect, i.e., a gelation in which the intermolecular cross-linkings are formed
3. The present experiments were still preliminary and a more systematic study containing EXAFS measurements of the influence of CM-chitin concentrations, degree of substitution, and addition of simple electrolyte has now been staeted to deduce to a more detailed picture of the specific adsorption mechanism of metal ions by CM-chitin.
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