Lee Lay-Theng, Leite Carlos A P, Galembeck Fernando
Instituto de Química, Universidade Estadual de Campinas, P. O. Box 6154, 13084-971 Campinas, SP, Brazil.
Langmuir. 2004 May 25;20(11):4430-5. doi: 10.1021/la049806t.
In this paper, we present an alternative approach for controlled nanoparticle organization on a solid substrate by applying dewetting patterns of charged polymer solutions as a templating system. Thin films of charged polymer solutions dewet a solid substrate to form complex dewetting patterns that depend on the polymer charge density. These patterns, ranging from polygonal networks to elongated structures that are stabilized by viscous forces during dewetting, serve as potential templates for two-dimensional nanoparticle organization on a solid substrate. Thus, while nanoparticles dried in pure water undergo self-assembly to form close-packed arrays, addition of charged polymer in the dispersion leads to the formation of open structures that are directed by the dewetting patterns of the polymer solution. In this study, we focus on the application of elongated structures resulting from dewetting of high-charge-density polymer solutions to align nanoparticles of silica and gold into long chains that are several micrometers in length. The particle ordering process is a two-step mechanism: an initial confinement of the nanoparticles in the dewetting structures and self-assembly of the particles within these structures upon further drying by lateral capillary attractions.
在本文中，我们提出了一种通过应用带电聚合物溶液的去湿图案作为模板系统，在固体基底上实现可控纳米粒子组装的替代方法。带电聚合物溶液的薄膜在固体基底上发生去湿，形成依赖于聚合物电荷密度的复杂去湿图案。这些图案，从多边形网络到在去湿过程中由粘性力稳定的细长结构，可作为在固体基底上进行二维纳米粒子组装的潜在模板。因此，当在纯水中干燥的纳米粒子进行自组装形成密排阵列时，在分散体中添加带电聚合物会导致形成由聚合物溶液的去湿图案引导的开放结构。在本研究中，我们专注于高电荷密度聚合物溶液去湿产生的细长结构的应用，以将二氧化硅和金纳米粒子排列成长度达数微米的长链。粒子排列过程是一个两步机制：纳米粒子最初被限制在去湿结构中，然后在进一步干燥时通过横向毛细管吸引力在这些结构内进行自组装。
