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International Agrophysics
publisher:Institute of Agrophysics
Polish Academy of Sciences
Lublin, Poland
ISSN: 0236-8722

vol. 16, nr. 2 (2002)

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Influence of a cyclodextrin on soil wettability
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Józefaciuk G.1, Hajnos M.1, Muranyi A.2
1 Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, P.O. Box 201, 20-290 Lublin 27, Poland
2 Research Institute for Soil Science and Agricultural Chemistry, Hungarian Academy of Sciences Herman Ottó 15, 1022 Budapest, Hungary

vol. 16 (2002), nr. 2, pp. 111-118
abstract The effect of various doses of the randomly methylated b-cyclodextrin on changes in surface free energy and wettability of a natural, and a humic acid enriched, loessial soil Orthic Luvisol was studied. A thin column wicking technique was used to determine the horizontal migration velocity vs. time depen- dence in the sample beds for a range of liquids of various surface tensions (surface free energies). From the latter dependencies the surface free energy and its components (water contact angles, works of adhesion and force of interparticle interaction via water layer) were estimated for the studied materials. The dispersive component of the surface free energy was least affected by the added cyclodextrin, however for the natural soil this markedly increased after the highest (2.5%w/w) cyclodextrin addition. The polar, acid-base component decreased in general with the cyclodextrin dose increase. The contribution of the electron-donor interactions to the polar surface free energy com- ponent decreased after low cyclodextrin doses (0.1 and 0.5%) and increased after the highest (2.5%) dose. Generally, the opposite tendency was noted for the electron-acceptor contribution. The wettability of the soil decreased at low cyclodextrin concentration and increased again at the highest load. The increase in the cyclodextrin concentration decreased the effective radius of the soil bed which caused an increase in the average force of in- teraction between soil particles via water layer, despite the simul- taneous decrease of adhesion forces of water to the soil.
keywords cyclodextrin, soil, surface free energy, wetta- bility