Organic-inorganic hybrid supramolecular gels of surfactant-encapsulated polyoxometalates.
Organic-inorganic hybrid supramolecular gels of surfactant-encapsulated polyoxometalates.
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DOI：
10.1021/la901869t
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发表时间：
2009-07
期刊：
影响因子：
--
通讯作者：
Yinglin Wang;Wen Li;Lixin Wu
中科院分区：
文献类型：
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作者：
Yinglin Wang;Wen Li;Lixin Wu
采用含两个烷基链的铵盐表面活性剂包封一系列多金属氧酸盐簇，制备了一种有机和无机组分协同自组装的新型杂化超分子凝胶。在我们使用的一般有机溶剂中，一些表面活性剂包封的POM （SEP）配合物很容易与非极性溶剂凝胶。从凝胶到溶液的临界胶凝浓度和转变温度的结果表明，适当的烷基链密度、烷基链长度和POM的形状有利于制备稳定的SEP凝胶。此外，极化光学显微镜和扫描电镜图像证实，POM的形状影响凝胶相中sep、条纹和球体的聚集形态。x射线衍射结果表明，所有凝胶态的sep都具有相似的层状聚集结构，内部有POM层，两侧有烷基链双层层屏蔽非极性溶剂。溶剂效应、静电和偶极相互作用的结合被认为是造成SEP凝胶的原因。
A new type of hybrid supramolecular gel derived from a synergetic self-assembling of organic and inorganic components has been prepared through encapsulating a series of polyoxometalate (POM) clusters with ammonium surfactants bearing two alkyl chains. Among the general organic solvents we employed, some of surfactant-encapsulated POM (SEP) complexes readily gel with nonpolar solvents. Proper alkyl chain density, alkyl chain length, and shape of POM are proven to be favorable for fabricating stable SEP gels based on the results of critical gelation concentration and transition temperature from gel to solution. In addition, the shape of POM influences the aggregation morphologies of SEPs, stripes and spheres in gel phases, as confirmed by polarizing optical microscopic and scanning electron microscopic images. X-ray diffractions reveal that all the SEPs in gel states possess similar lamellar aggregation structures with POM layer inside and alkyl chain bilayers shielding from the nonpolar solvent on both sides. The combination of solvent effect, electrostatic, and dipole interaction is thought to be responsible for the formation of SEP gels.