Adsorption of salicylic acid on bentonite and kaolin and release experiments
Adsorption of salicylic acid on bentonite and kaolin and release experiments
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DOI：
10.1016/j.clay.2006.07.008
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发表时间：
2007-04-01
影响因子：
5.6
通讯作者：
Tateo, F.
中科院分区：
文献类型：
--
作者：
Bonina, F. P.;Giannossi, M. L.;Tateo, F.
这项工作研究了两种商业粘土，一种膨润土和一种高岭土，以及一种铁-水杨酸盐复合体之间的相互作用。用含Fe(III)0.0176 M和水杨酸0.0253 M的水溶液进行吸附实验，用化学分析、粉末X射线衍射、热分析对天然粘土和处理后的粘土样品进行了表征。膨润土对水杨酸的吸附随时间的变化与水杨酸的吸附百分数呈一级动力学关系。在最初的12小时内，反应速度减慢。反应在2天后完全结束，在接下来的4天内，膨润土中水杨酸的浓度与其渐近值8.0%保持不变。高岭土对水杨酸的吸附动力学表明，处理4d后开始缓慢吸附，19d后基本结束。水杨酸的吸附量为最终络合物的5.5%。测定了膨润土和高岭土在0.2N的Na+、K+、Mg2+和Ca2+溶液中吸附的水杨酸的释放情况。用Franz型扩散池测定了含Fe(III)-水杨酸的膨润土在醋酸纤维素膜上的水杨酸释放速率：水杨酸开始缓慢释放，然后是快速释放阶段，23h后释放的水杨酸浓度可以认为是恒定的，解吸的药物是膨润土吸附的1.4%。即使水杨酸的解吸量不是很高，膨润土-水杨酸盐复合体也可以通过逐渐释放而适合应用。(C)2006 Elsevier B.V.，所有比赛已预订。
The work deals the interactions between two commercial clays, a bentonite and a kaolin, and an iron-salicylate complex. Adsorption experiments were accomplished using a water solution containing Fe(III) 0.0176 M and salicylic acid 0.0253 M. Natural and treated clay samples were characterized by chemical analyses, powder X-ray diffraction, thermal analyses. The time dependence of salicylic acid adsorption by bentonite follows first-order kinetics, with respect to the percentage of salicylic acid adsorbed. in the first 12 h; afterwards the reaction slows down. The reaction is completely exhausted after 2 days and during the next 4 days the concentration of salicylic acid in bentonite does not change from its asymptotic value of 8.0%. The adsorption kinetics of salicylic acid by kaolin highlights a slow adsorption beginning after the fourth day of treatment, and finished after 19 days. The amount of salicylic acid adsorbed was 5.5% of the final complex. The release of salicylic acid adsorbed by bentonite and kaolin was tested in 0.2 N solutions of Na+, K+, Mg2+, and Ca2+. Salicylic acid release rates from Fe(III)-salicylate-containing bentonite were also measured through cellulose acetate membranes by means of Franz-type diffusion cells: an initial slow release of salicylic acid was followed by a fast release phase; after 23 h the concentration of salicylic acid released can be considered constant and the drug desorbed was 1.4% of the amount adsorbed by the bentonite. Even if the desorbed amount of salicylic acid is not very high, the bentonite-salicylate complex could be suitable for an application by gradual release. (c) 2006 Elsevier B.V. All fights reserved.