Wang Yonghui, Wang Xinlong, Hu Changwen
Institute of Polyoxometalate Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, People's Republic of China.
J Colloid Interface Sci. 2002 May 15;249(2):307-15. doi: 10.1006/jcis.2002.8295.
Ultrathin multilayer films of two lanthanide polyoxometalates (LPOMs), K(17)[Eu(P(2)W(17)O(61))(2)] (EPW) and K(13)[Eu(SiW(11)O(39))(2)] (ESW), and poly(allylamine hydrochloride) (PAH) have been prepared by layer-by-layer self-assembly from dilute aqueous solutions. UV-vis spectroscopy and ellipsometry respectively show that the absorbance values at characteristic wavelengths and the thicknesses of the multilayer films increase linearly with the number of LPOM/PAH bilayers, suggesting that the deposition process is linear and highly reproducible from layer to layer. Average thicknesses of ca. 3.4 and 2.4 nm were determined for the EPW/PAH and ESW/PAH bilayers by ellipsometry, respectively. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) images provide the surface morphology of the LPOM/PAH films, indicating that the film surface is relatively uniform and smooth. The photoluminescent properties of these films have also been investigated by fluorescence spectroscopy. The LPOM/PAH multilayer film has a good thermal stability as shown by UV-vis, X-ray photoelectron, and fluorescence spectra.
通过从稀水溶液中逐层自组装制备了两种镧系多金属氧酸盐（LPOMs），即K(17)[Eu(P(2)W(17)O(61))(2)]（EPW）和K(13)[Eu(SiW(11)O(39))(2)]（ESW）与聚（烯丙胺盐酸盐）（PAH）的超薄多层膜。紫外可见光谱和椭偏仪分别表明，多层膜在特征波长处的吸光度值和厚度随LPOM/PAH双层数线性增加，这表明沉积过程是线性的，并且层与层之间具有高度可重复性。通过椭偏仪分别测定EPW/PAH和ESW/PAH双层的平均厚度约为3.4和2.4 nm。此外，扫描电子显微镜（SEM）和原子力显微镜（AFM）图像提供了LPOM/PAH膜的表面形貌，表明膜表面相对均匀且光滑。还通过荧光光谱研究了这些膜的光致发光特性。紫外可见光谱、X射线光电子能谱和荧光光谱表明，LPOM/PAH多层膜具有良好的热稳定性。
