New Syntheses of Hyperbranched Ultrathin Grafts

这一提议将利用非特异性分子识别、响应表面和多价性来使嫁接更快、更有效。该化学将利用接枝化学在有机和无机基质上制备功能性、超薄、超支化的接枝。要制备的功能界面都将以共价键组装。这些共价组装体将来自已知的反应-缩合反应，如酰胺化反应和催化反应，如由炔烃和叠氮化物生成三氮唑。这种接枝将含有官能团，可以用光谱探针进一步修饰，这样形成的界面将有助于改性聚烯烃和金属氧化物等常见材料的物理和化学性质。这项提议的智力影响是，它将展示如何以有用的合成方式利用多价性的已知优势、分子识别原理和大分子体系的响应特性。这项拟议的工作将使用弱分子间相互作用，如氢键，将试剂和催化剂定位在界面上。这种试剂的本地化将通过增加参与成键的试剂的相对浓度来促进接枝。这种效果将使嫁接变得更简单、更实用，并减少试剂的浪费。如果这项研究成功，这项研究将导致功能表面可以设计成便于智能地自己嫁接。这项提议更广泛的影响是它对本科生和研究生的科学培训和教育的影响。通常情况下，每年会有2-3名来自德克萨斯农工大学及其他地方的本科生参加，其中一些在夏季，另一些在学年。这些本科生将与2-3名研究生并肩工作。所有学生都将在研究中扮演个人和创造性的角色，所有人都将在地方、地区和国家会议上参与出版物和演讲。

This proposal will employ nonspecific molecular recognition, responsive surfaces and polyvalency to make grafting faster and more efficient. The chemistry will employ graft-on-a-graft chemistry to prepared functional, ultrathin, hyperbranched grafts on both organic and inorganic substrates. The functional interfaces to be prepared will all be assembled with covalent bonds. These covalent assemblies will be derived from known reactions - condensation reactions like amidation and catalytic reactions like triazole formation from alkynes and azides. Such grafts will contain functional groups that can be further modified with spectroscopic probes and the interfaces so formed will be useful in modification of the physical and chemical properties of common materials like polyolefins and metal oxides. The intellectual impact of this proposal is that it will demonstrate ways to use the known advantages of polyvalency, the principles of molecular recognition and the responsive character of macromolecular systems in a useful synthetic way. The proposed work will use weak intermolecular interactions like hydrogen bonding to localize reagents and catalysts at interfaces. Such localization of reagents will facilitate grafting by increasing the relative concentrations of the reagents involved in bond formation. Such effects will make grafting simpler, more practical and less wasteful in terms of reagents. If successful, this research will lead to functional surfaces can be designed so as to intelligently facilitate their own grafting. The broader impact of this proposal is its effect on the scientific training and education of students at both the undergraduate and graduate level. Typically 2-3 undergraduates from Texas A&M and outside will be involved each year, some in the summer and some during the school year. These undergraduates will work side-by-side with 2-3 graduate students. All students will have individual and creative roles in the research and all will participate in publications and presentations at local, regional and national meetings.