NER: Polymer Nanowires Synthesized on a Flat Surface Via a Surfactant Template

纳米材料提供了许多潜在的技术应用，因为与传统的大尺度类似物相比，这些材料固有的不同寻常的性质。导电聚合物是纳米尺度合成的主要目标，因为它们的导电性由于高度取向的形态而大大增强。在这个方案中，PI首次表明，在吸附表面活性剂模板的情况下，在高度有序的热解石墨(HOPG)和云母上氧化合成了半径几乎均匀的取向聚苯胺(PANI)纳米线。他们也用聚吡咯合成了类似的结构，但不是按顺序合成的。合成结构的尺寸随衬底的不同而不同。如果能确定一种方法来制造半径几乎均匀的导电纳米线，使其中心到中心的距离是规则的和可控的，那么这将在许多领域产生重大影响，特别是在微电子行业。使他们取得这些进展的重要技术发现是，表面活性物质的吸附单层可以在固-液界面形成非常独特的结构。结构的类型从亲水性表面上的圆柱形、球状和平坦的双层到疏水表面上的半圆柱形、半球状和单分子层。利用其他人的工作结果，他们能够选择特定的表面活性剂结构作为图案化模板。他们的实验取得了成功，在吸附半圆柱体的特定情况下，所得到的薄膜对于某些聚合物和表面也具有看起来像半圆柱体的形态。填充物的尺寸被测量到直径在50到100纳米之间，长达150微米。这一令人兴奋的新发现和这项赠款中描述的工作都在过去4个月内完成。尽管AFM显微照片清楚地支持了他们的说法，但他们对一些关键问题的理解并不完整。例如，结构在尺寸(高度和宽度)上明显不同，这取决于所使用的基材和单体。导线合并；最重要的问题之一是了解这些导线合并的原因，并确定如果可能的话，减少或阻止合并的方法。他们对这些纳米线的性质几乎一无所知，包括它们的导电性，显然这些纳米线的性质是极其重要的。这笔赠款将使他们能够探索所有这些问题，并帮助他们实现最终目标，即在非常大的长度范围内合成沿一个方向定向的完全分散的纳米线。

Nanoscale materials offer many potential technological applications due to the unusual properties inherent in these materials compared to their traditional macroscale analogues. Conducting polymers are prime targets for nanoscale synthesis as their conductivity is greatly enhanced by highly oriented morphologies. In this proposal, The PI's show for the first time that oriented polyaniline (PANI) nanowires, with almost uniform radii, have been oxidatively synthesized on highly ordered pyrolytic graphite (HOPG) and on mica using anadsorbed surfactant template. They have also synthesized similar structures, but not as ordered, using polypyrrole. The dimensions of the synthesized structure vary depending on the substrate. If a way can be determined to produce conducting nanowires with almost uniform radii so that their center-to-center distances are regular and controllable, then this would have substantial impact in many areas, particularly in the microelectronics industry.The important technological discovery that has allowed them to make these advances is the fact that adsorbed monolayers of surfactant can form very unique structures at the solid-liquid interface. The type of structures range from cylinders, spheres and flat bilayers on hydrophilic surfaces, to half cylinders, half spheres and monolayers on hydrophobic surfaces. Using the results of work done by others, they were able to choose a specific surfactant structure as a patterning template. Their experiments have been successful, in the specific case of adsorbed half-cylinders the resulting film also has what appears to be a half-cylinder morphology for certain polymers and surfaces. The dimensions of the fillers have been measured to be between 50 and 100 nm in diameter, and as long as 150 microns.This exciting new discovery and the work described in this grant have all been completed over the last 4 months. Although AFM micrographs clearly support their claims, their understanding of some critical issues is not complete. For example, the structures vary significantly in dimension (height and width) depending on the substrate and monomer that is used. The wires coalesce; one of the most important issues is to understand why these wires coalesce, and determine, if possible, a way to reduce or arrest coalescence. They know almost nothing about the properties of these nanowires, including their conductivity, and clearly the properties of the wires is extremely important. This grant will enable them to explore all of these issues and help them to achieve the ultimate goal, the synthesis of fully dispersed nanowires oriented in one direction over very large length scales.