Abstract

Comprehensive adsorption and spectral studies are performed for the interaction between caffeic acid and pyrogenic alumina in aqueous solutions. It is shown that sorption begins at pH >2.5 and reaches its maximum values in a neutral medium. The sorption isotherm of caffeic acid is the H-type isotherm characteristic of chemisorption. It is found that adsorption proceeds according to two mechanisms simultaneously: due to interaction between the surface groups of the sorbent and (a) the carboxyl group of caffeic acid or (b) the ortho-hydroxyl group of the acid to form a chelate complex, the relative fraction of which grows along with the pH of the solution.

中文翻译：

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水溶液中热解氧化铝对咖啡酸的吸附

摘要

对水溶液中咖啡酸和热解氧化铝之间的相互作用进行了全面的吸附和光谱研究。结果表明，吸附在 pH > 2.5 时开始，并在中性介质中达到最大值。咖啡酸的吸附等温线是化学吸附的 H 型等温线。发现吸附同时根据两种机制进行：由于吸附剂的表面基团与 (a) 咖啡酸的羧基或 (b) 酸的邻羟基相互作用形成螯合物，其相对分数随着溶液的 pH 值而增加。