Das Soma, Raychaudhuri A K
DST Unit for Nanosciences, S. N. Bose National Center for Basic Sciences, JD Block, Sector-III, Salt Lake, Kolkata 700098, India.
J Nanosci Nanotechnol. 2009 Sep;9(9):5362-6. doi: 10.1166/jnn.2009.1111.
In this paper, we report synthesis of atomically smooth Ni-arachidate films using Langmuir-Blodgett technique. The interaction between arachidic acid monolayer and nickel ion has been investigated as a function of subphase pH by measuring the compression isotherms at the air/water interface. As the pH is increased, the compressible liquid (L2) phase is observed over a smaller range of surface pressure (pi) and area/mol (A) until at high enough pH the L2 phase is altogether absent. A further increase in pH does not result in any additional change in the isotherm. This is a general trend observed for all bivalent cations but the disappearance of L2 phase occurs at different pH values for different ions. The atomically smooth monolayers are deposited when the pressure is beyond the L2 phase (typically approximately 35 mN/m). Along with the isotherms, monolayer of nickel arachidate deposited on mica, were studied thoroughly using Atomic force Microscopy. Atomic force microscope images show atomically smooth and defect free surface of nickel arachidate transferred on mica substrate. The images allow proper determination of the lattice vectors.
在本文中，我们报道了使用朗缪尔-布洛杰特技术合成原子级光滑的花生酸镍薄膜。通过测量空气/水界面的压缩等温线，研究了花生酸单分子层与镍离子之间的相互作用随亚相pH值的变化。随着pH值升高，可压缩液相（L2）相在较小的表面压力（π）和面积/摩尔（A）范围内被观察到，直到在足够高的pH值下L2相完全消失。pH值的进一步升高不会导致等温线的任何额外变化。这是所有二价阳离子都观察到的普遍趋势，但不同离子的L2相消失发生在不同的pH值。当压力超过L2相（通常约为35 mN/m）时，原子级光滑的单分子层就会沉积下来。除了等温线，还使用原子力显微镜对沉积在云母上的花生酸镍单分子层进行了深入研究。原子力显微镜图像显示了转移到云母基底上的花生酸镍的原子级光滑且无缺陷的表面。这些图像能够准确确定晶格矢量。
