Linear and Side-Functionalized Macromolecular Adsorbates for Enhanced Versatility in the Self-Assembly at Surfaces

提案编号：CBET：0731168主要研究者：G. Kane Jennings大学/机构：范德比尔特大学线性和侧功能化高分子吸附剂用于增强表面自组装的多功能性本项目将开发两类巯基封端的高分子吸附剂，用于在金属表面自组装具有独特性能的分子厚膜。一类硫醇由具有各种末端的线性聚亚甲基组成，所述末端包括烷基、全氟烷基和甲氧基封端的低聚（乙二醇）基团。另一类由聚亚甲基系链组成，其含有无规分布的官能侧链，包括羧酸、酯和非极性基团，沿着烷基末端。这些新的大分子吸附物将通过多同系化制备，这是一种高度受控的聚合，产生几乎单分散的长链醇，其具有受控的长度和侧链组成，可以转化为硫醇，以使其能够在不同的金属表面上化学吸附。这些独特的吸附物将被研究应用于超快速和敏感的pH响应薄膜和3-D单层模板的图案化和捕获和取向的一个关键的完整的膜蛋白。智力优势。该项目将产生两类新的硫醇吸附物，并将展示如何将对结构和组成的精确大分子控制与分子自组装相结合，以制备创新的新材料。线性类的吸附物，预计将产生最厚和最保护类的单层膜尚未制备，并将用于制备模板蚀刻，沉积，和生物分子截留和取向。分支类的吸附物应该能够定制的单层结晶度和开放的响应膜领域的单层的新应用。对这些长链吸附物组装的研究将对吸附物-吸附物相互作用的作用产生基本的了解，包括氢键和静电排斥，以及分子膜形成过程中的溶剂-吸附物相互作用。我们期望从这些吸附物制备的薄膜定义新的稳定性标准，阻隔性能和多功能性，同时呈现技术上重要的表面，可以选择为低能量或生物惰性。更广泛的影响。 所提出的薄膜在化学传感器、防腐蚀或蚀刻的保护性屏障层以及促进表面蛋白质取向的独特模板中具有关键应用。 响应于局部pH的膜可用于在被固定化酶或其他受体结合时发出分析物化合物存在的信号。 对于感测的商业相关性，膜必须表现出大的、快速的和尖锐的响应。 由于它们的疏水性、薄度和定制的组成，所提出的具有稀羧基侧基的膜应该产生迄今为止制备的任何有机膜的最大、最快和最尖锐的pH响应。 这种高性能将为这些单分子膜在化学传感器中的商业开发创造机会，其中pH响应用作转导信号。 该项目将研究与研究生和本科教育以及推广到K-12学生相结合。PI是学校和大学一级的获奖教师，他将从这项研究中开发模块和案例研究，以影响他每年教的~100名新生，~30名大三学生和~20名研究生。对自组装和薄膜感兴趣的本科生将被引导到进一步的分子课程，包括PI自己的化学工程课程的分子方面，以及该项目每年资助的两个本科生研究职位。PI正在开发一个纳米技术课程，他将通过范德比尔特的天才教育暑期学院（SAGE）于2007年7月教授高中生和大三学生，并在每年夏天继续。这项研究的例子将提供动手设计项目，以提高这些聪明的年轻学生的分子直觉。此外，PI将继续通过校园NSF资助的教师研究经验计划，每年夏天在他的小组中接待一名高中教师

Proposal Number: CBET: 0731168 Principal Investigator: G. Kane JenningsUniversity/Institution: Vanderbilt UniversityTitle: Linear and Side-Functionalized Macromolecular Adsorbates for Enhanced Versatility in the Self-Assembly at Surfaces This project will develop two classes of thiol-terminated macromolecular adsorbates for self-assembly of molecularly thick films with unique properties onto metal surfaces. One class of thiols consists of linear polymethylene with various termini, including alkyl, perfluoroalkyl, and methoxy-terminated oligo(ethylene glycol) groups. Another class consists of a polymethylene tether that contains randomly distributed functional side chains, including carboxylic acid, ester, and nonpolar groups, along with alkyl termini. These novel macromolecular adsorbates will be prepared by polyhomologation, a highly controlled polymerization that yields nearly monodisperse, long-chain alcohols with controlled length and side chain composition that can be converted to thiols to enable chemisorption at different metal surfaces. These unique adsorbates will be investigated for applications in ultra-fast and -sensitive pH-responsive thin films and 3-D monolayer templates for patterning and for entrapment and orientation of a key integral membrane protein. Intellectual Merit. The project will generate two new classes of thiol adsorbates and will demonstrate how precise macromolecular control over architecture and composition can be combined with molecular self-assembly to prepare innovative new materials. The linear class of adsorbates is expected to yield the thickest and most protective class of monolayer films yet prepared and will be used to prepare templates for etching, deposition, and biomolecule entrapment and orientation. The branched class of adsorbates should enable a tailoring of monolayer crystallinity and open new applications for monolayers in areas of responsive films. A study into the assembly of these long-chain adsorbates will yield fundamental insight into the roles of adsorbate-adsorbate interactions, including hydrogen bonding and electrostatic repulsion, and solvent-adsorbate interactions during molecular film formation. We expect the films prepared from these adsorbates to define new standards of stability, barrier performance, and versatility while presenting technologically important surfaces that can be selected as either low-energy or biologically inert. Broader Impacts. The proposed films are primed for key applications in chemical sensors, protective barrier layers against corrosion or etching, and unique templates to promote protein orientation at surfaces. Films that respond to local pH are useful in signaling the presence of analyte compounds when bound by immobilized enzymes or other receptors. For commercial relevance in sensing, the film must exhibit a large, rapid, and sharp response. Due to their hydrophobicity, thinness, and tailored composition, the proposed films with dilute carboxyl side groups should yield the largest, fastest, and sharpest response to pH of any organic film prepared to date. Such high performance would create opportunities for commercial development of these monolayers in chemical sensors where a pH response serves as the transduction signal. The project will integrate research with graduate and undergraduate education as well as outreach to K-12 students. The PI is an award-winning teacher at the School and University levels, and he will develop modules and case studies from this research to impact the ~100 freshmen, ~30 juniors, and ~20 graduate students he teaches each year. Undergraduate students who show interest in self-assembly and thin films will be steered toward further molecular-based coursework, including the PI's own Molecular Aspects of Chemical Engineering course, as well as the two undergraduate research positions funded per year within the project. The PI is developing a course on Nanotechnology that he will teach to high school sophomores and juniors through the Summer Academy for Gifted Education (SAGE) at Vanderbilt in July of 2007 and continuing each summer. Examples from this research will provide hands-on design projects to enhance the molecular intuition of these bright young students. In addition, the PI will continue to host a high school teacher in his group each summer through the on-campus NSF-funded Research Experiences for Teachers program