Resumo

MORONTA, D; MARTIN-LANDROVE, M; GAGO, C  e  PARDEY, A.J. Proposition of two layered ionic structures, with xy disorder but z-ordered, in a quasi-liquid system. Rev. mex. fis. [online]. 2006, vol.52, suppl.3, pp.208-210. ISSN 0035-001X.

Boundary layers at the liquid-solid interface of increasing concentrations of CuSO4 aqueous solutions in contact with glass have been studied. An orderly sequence of Cu²⁺ - SO²₄ - Cu²⁺- SO^2-₄ solvated ionic sub-layers parallel to the glass are formed, being the first one electrostatically anchored to the surface. Cu²⁺ EPR line intensity, and NMR proton relaxation T₂ studies show outstanding similarities, which can be explained by the presence of different stages of ionic organization with the concentration, at the semi-liquid boundary layers. At a critical concentration C_m, two stable local layers (of two sub-layers each) of ions are proposed to be present. In them, the ions in the xy, parallel to the wall plane are randomly distributed, but with the proposed order in z perpendicular to the wall axis.

Palavras-chave : Boundary layers; EPR; NMR; ionic order; magnetic ordering; CuSO4.

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