Institut für Chemie und Biochemie, Physikalische und Theoretische Chemie, Freie Universität Berlin , Takustraße 3, D-14195 Berlin, Germany.
ACS Nano. 2016 Mar 22;10(3):3525-35. doi: 10.1021/acsnano.5b07782. Epub 2016 Mar 3.
In light of the importance of nanostructured surfaces for a variety of technological applications, the quest for simple and reliable preparation methods of ordered, nanometer ranged structures is ongoing. Herein, a versatile method to prepare ordered, non-close-packed arrangements of nanoparticles on centimeter sized surfaces by self-assembly is described using monodisperse (118-162 nm Ø), amino-functionalized silica nanoparticles as an exploratory example. It is shown that the arrangement of the particles is governed by the interplay between the electrostatic repulsion between the particles and the interaction between particles and surfaces. The latter is tuned by the properties of the particles such as their surface roughness as well as the chemistry of the linkage. Weak dispersive interactions between amino groups and gold surfaces are compared to a covalent amide linkage of the amino groups with carboxylic acid functionalized self-assembled monolayers. It was shown that the order of the former systems may suffer from capillary forces between particles during the drying process, while the covalently bonded systems do not. In turn, covalently bonded systems can be dried quickly, while the van der Waals bonded systems require a slow drying process to minimize aggregation. These highly ordered structures can be used as templates for the formation of a second, ordered, non-close-packed layer of nanoparticles exemplified for larger polystyrene particles (Ø 368 ± 14 nm), which highlights the prospect of this approach as a simple preparation method for ordered arrays of nanoparticles with tunable properties.
鉴于纳米结构表面在各种技术应用中的重要性，人们一直在寻求简单可靠的制备有序纳米结构的方法。在此，我们描述了一种利用单分散（118-162nmØ）、氨基功能化的二氧化硅纳米颗粒作为探索性示例，在厘米级表面上通过自组装制备有序、非密堆积纳米颗粒排列的通用方法。结果表明，颗粒的排列受颗粒间静电排斥和颗粒与表面间相互作用的共同影响。后者可以通过颗粒的性质（如表面粗糙度以及连接的化学性质）进行调节。与氨基与金表面的弱色散相互作用相比，我们比较了氨基与羧酸功能化自组装单层的酰胺键的共价键合。结果表明，前者体系的有序性可能会在干燥过程中受到颗粒间的毛细作用力的影响，而后者则不会。反过来，共价键合体系可以快速干燥，而范德华键合体系需要缓慢干燥以最小化聚集。这些高度有序的结构可用作形成第二有序、非密堆积层纳米颗粒的模板，例如较大的聚苯乙烯颗粒（Ø 368 ± 14nm），这突出了该方法作为一种具有可调性质的纳米颗粒有序排列的简单制备方法的前景。
