Experimental investigations of amino acid-layered double hydroxide complexes: Glutamate-hydrotalcite
Experimental investigations of amino acid-layered double hydroxide complexes: Glutamate-hydrotalcite
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DOI：
10.1021/cm052107x
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发表时间：
2006-04
影响因子：
8.6
通讯作者：
M. Reinholdt;R. Kirkpatrick
中科院分区：
文献类型：
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作者：
M. Reinholdt;R. Kirkpatrick
插入氨基酸谷氨酸 (GA) 的水滑石 (HT) 的 XRD、TGA−DTA、成分分析和 13C NMR 数据提供了合成 pH、合成温度和水合状态对 GA−HT 复合物结构和组成影响的详细图片。在 50 至 70 °C 的温度和接近 10 的 pH 值（pH 范围 8−12）下，GA 最有效地融入 HT 中间层，并且大部分 GA 吸附在 HT 颗粒表面。 1H−13C CP-MAS NMR 谱表明，GA-2 阴离子的相对丰度随着 pH 值的增加而增加，表明在 100% 相对湿度 (RH) 下，外表面的 GA 出现在表面液膜中。对于在 pH 10 下合成的样品，实际 GA-2:GA-1 比率接近 1，仅使用 13C MAS NMR 测定富含 13C 的样品。在低相对湿度下，层间 GA 与各层平行；在 79% RH 时，它的长轴与各层成一个大角度，而在 100% RH 时，低 2θ 值时会出现宽底反射……
XRD, TGA−DTA, compositional analyses, and 13C NMR data for hydrotalcite (HT) intercalated with the amino acid glutamic acid (GA) provide a detailed picture of the effects of synthesis pH, synthesis temperature, and hydration state on the structure and composition of the GA−HT complexes. GA is most effectively incorporated into HT interlayers at temperatures between 50 and 70 °C and pH values near 10 (pH range 8−12), and much of the GA is adsorbed on HT particle surfaces. 1H−13C CP-MAS NMR spectra show that the relative abundance of GA-2 anions increases with increasing pH and suggest that at 100% relative humidity (RH), the GA on exterior surfaces occurs in a surface fluid film. The actual GA-2:GA-1 ratio, which is close to 1 for a sample synthesized at pH 10, is determined only for a 13C-enriched sample using 13C MAS NMR. At low RH, interlayer GA lies parallel to the layers; at 79% RH, it occurs with its long axis at a high angle to the layers, and at 100% RH, the broad basal reflection at low 2θ values ...