Gasser M S
Hot Labs Centre, Atomic Energy Authority, P.Code 13759, Cairo, Egypt. mona
Colloids Surf B Biointerfaces. 2009 Oct 1;73(1):103-9. doi: 10.1016/j.colsurfb.2009.05.005. Epub 2009 May 14.
ZnFe- and MgFe-LDHs were prepared by the anion exchange method, with the aim of adsorption of the ascorbic acid from the aqueous solutions by ion exchange process between anionic derivatives in LDH (Cl) and the anionic vitamin. This leads to successful intercalation of the vitamin into gallery space of LDH that offers a new route to safe preservation of bioactivity as well as controlled release. The prepared LDHs were characterized by XRD, TG-DTA and FT-IR spectroscopy. Adsorption of the ascorbic acid by the LDH under investigation was studied in terms of pH value, amount of LDH, contact time, VC (ascorbate) concentration and chemical composition of the host materials. The results indicate the relatively fast adsorption of the anionic vitamin by ZnFe-LDH-Cl and MgFe-Cl-LDH; reaches the equilibrium in 60 min. The shapes of the adsorption isotherms suggest specific interaction and high affinity. The batch kinetics of ascorbic acid adsorption onto ZnFe-Cl and MgFe-Cl-LDHs were studied. Furthermore, their release behaviors are also examined by spontaneous deintercalation with carbonate anion.
通过阴离子交换法制备了锌铁和镁铁层状双氢氧化物（LDHs），目的是通过LDH（Cl）中的阴离子衍生物与阴离子维生素之间的离子交换过程，从水溶液中吸附抗坏血酸。这导致维生素成功插入LDH的层间空间，为生物活性的安全保存以及控释提供了一条新途径。通过X射线衍射（XRD）、热重-差示热分析（TG-DTA）和傅里叶变换红外光谱（FT-IR）对制备的LDHs进行了表征。从pH值、LDH用量、接触时间、VC（抗坏血酸盐）浓度和主体材料的化学成分等方面研究了所研究的LDH对抗坏血酸的吸附。结果表明，锌铁-LDH-Cl和镁铁-Cl-LDH对阴离子维生素的吸附相对较快；在60分钟内达到平衡。吸附等温线的形状表明存在特定相互作用和高亲和力。研究了抗坏血酸在锌铁-Cl和镁铁-Cl-LDHs上的间歇吸附动力学。此外，还通过与碳酸根阴离子的自发脱插层研究了它们的释放行为。
