ULTRATHIN LAYERS AND SUPRAMOLECULAR ARCHITECTURE OF ISOPENTYLCELLULOSE
ULTRATHIN LAYERS AND SUPRAMOLECULAR ARCHITECTURE OF ISOPENTYLCELLULOSE
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异戊纤维素的超薄层和超分子结构
DOI：
10.1021/ma00108a059
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发表时间：
1995
期刊：
影响因子：
5.5
通讯作者：
S. Satija
中科院分区：
文献类型：
--
作者：
M. Schaub;C. Fakirov;A. Schmidt;Günter Lieser;G. Wenz;G. Wegner;P. Albouy;Hong Wu;M. Foster;C. Majrkzak;S. Satija
描述了用朗缪尔-布洛杰特技术组装的三-O-异戊基纤维素多层膜的表征。通过X射线反射对超薄膜的分析证实，薄膜的整体质量是均匀的，但没有显示任何布拉格反射。然而，用中子反射法研究了一种交替的多层样品的超结构，发现了一种完美的周期性层状结构。研究了异戊基纤维素醚的取代度对多层膜形成和结构的影响。部分取代的异戊基纤维素多层膜表现出由双层组成的周期性薄膜结构。薄膜的完好性不受残馀羟基的影响。用电子衍射法研究了三氧异戊基纤维素多层膜的面内结构。纤维素醚形成三重对称的螺旋，螺旋轴取向优先平行于浸渍方向。在退火后，得到了层状结构的三维晶膜，其中的链被堆积在一个单斜晶胞中。层状超结构中直径小于10A/分子的纤维素衍生物的直径非常小，并且通过Langmuir-Blodgett技术获得了非常完美和均匀取向的多层膜，这增加了分子架构师对合理构建超分子结构感兴趣的工具箱。
The characterization of multilayers from tri-O-isopentyl cellulose assembled by the Langmuir-Blodgett technique is described. The analysis of ultrathin films by X-ray reflection confirmed a homogeneous overall film quality but did not show any Bragg reflection. However, investigation of a superstructure in terms of an alternating multilayer sample from deuterated and nondeuterated isopentylcellulose ethers by neutron reflection revealed a perfectly periodic layer structure. The influence of the degree of substitution of the isopentylcellulose ethers on the formation and structure of multilayers was investigated as well. Multilayers of partially substituted isopentylcellulose exhibit a periodical film structure composed of double layers. The perfection of the films is not influenced by the residual OH functions. The in-plane structure of tri-O-isopentylcellulose multilayers was investigated by electron diffraction in transmission geometry. The cellulose ether forms a helix of 3-fold symmetry, and the helix axes are preferentially oriented parallel to the dipping direction. Upon annealing a three-dimensional crystalline film of layered structure is obtained in which the chains are packed in a monoclinic unit cell. The very small diameter of the cellulose derivatives of less than 10 A/molecule in the layered superstructures and the observation that very perfect and homogeneously oriented multilayers are obtained by the Langmuir-Blodgett technique augment the toolbox of molecular architects interested in the rational construction of supramolecular architectures.