Iyi Nobuo, Ebina Yasuo, Sasaki Takayoshi
National Institute for Materials Science, Ibaraki, Japan.
Langmuir. 2008 May 20;24(10):5591-8. doi: 10.1021/la800302w. Epub 2008 Apr 29.
LDH hybrids were synthesized from Cl (-)MgAl-LDHs by anion exchange with short-chain alkyl carboxylate intercalants: C n H 2 n+1 COO (-) ( n = 0-3). Among them, LDH3 (LDH with Mg/Al = 3) hybrids containing acetate ( n = 1) and propionate ( n = 2) exhibited swelling behavior in water. The action of water on acetate-LDH3 (AcO-LDH3) and propionate-LDH3 (PrO-LDH3) led to semitransparent suspensions via a viscous gel state. From the X-ray diffraction profiles of the gels, only a broad feature was observed by the loss of the sharp reflections. The reflections reappeared for the films obtained by drying the gel, indicating the restacking of the LDH nanosheets into the original stacked structure. Observation using atomic force microscopy revealed delaminated nanosheets with a thickness of 1.1-1.5 nm with the same morphological features as the starting LDHs. XRD measurement and AFM observation supported the formation of unilamellar LDH sheets. Semitransparent self-standing LDH films were obtained by peeling off the films formed on a PE (polyethylene) substrate by drying the colloidal suspension thereon. The thickness of the obtained flexible films ranged from 10 to 25 microm, and they could be anion exchanged with inorganic and organic anions in the film state.
CₙH₂ₙ₊₁COO⁻（n = 0 - 3）与Cl⁻MgAl - LDHs进行阴离子交换合成了LDH杂化物。其中，含有乙酸根（n = 1）和丙酸根（n = 2）的LDH3（Mg/Al = 3的LDH）杂化物在水中表现出溶胀行为。水对乙酸根 - LDH3（AcO - LDH3）和丙酸根 - LDH3（PrO - LDH3）的作用通过粘性凝胶态导致形成半透明悬浮液。从凝胶的X射线衍射图谱中，由于尖锐反射的消失仅观察到一个宽峰。对于通过干燥凝胶获得的薄膜，反射重新出现，表明LDH纳米片重新堆叠成原始的堆叠结构。使用原子力显微镜观察发现，分层的纳米片厚度为1.1 - 1.5 nm，具有与起始LDH相同的形态特征。XRD测量和AFM观察支持了单层LDH片的形成。通过剥离在PE（聚乙烯）基板上干燥胶体悬浮液形成的薄膜，获得了半透明的自立式LDH薄膜。所得柔性薄膜的厚度范围为10至25微米，并且它们可以在薄膜状态下与无机和有机阴离子进行阴离子交换。
