Assembling Dendritic and Branched Molecules at Interfaces

该项目解决了具有各种功能化核心和分支的树枝状和分支分子的界面状态，如两亲性单枝分子，分支圆盘和超支化聚合物。 该项目的最终目标是了解新型树枝状和支化分子的化学结构-界面组织-界面性质之间的基本关系，这些分子具有可变的形状和对称性，支化的程度和性质，可变的两亲性平衡和锚定能力。 对于这样的分子，表面锚定可以发生在明确定义的单个或多个点。 这种锚定应该使表面上的分子稳定，但仍然允许外壳具有足够的流动性，以形成具有外部官能团的有组织的纳米组装体。 对于这样的组装，单子叶植物壳的末端基团完全暴露于外部相互作用。 在进一步发展这一概念，以前探索的选择将扩大，包括新类型的分子：盘，杆，和发夹分支的两亲物，具有锚定焦点的单枝，杂臂星形聚合物，官能化超支化，和磷有机树枝状聚合物。这项研究将解决几个重要的问题：化学成分和形状持久的核心和灵活的分支的对称性如何影响界面力的平衡？ 什么是在空气-水界面和固体表面形成稳定有序单分子膜的最佳平衡？ 表面锚定是如何受到树枝状结构的影响？ 线性大分子的化学和静电驱动的自组装原理如何在复杂的分支大分子中发挥作用？更广泛的影响包括促进PI小组与美国科学和工程部门的其他研究人员之间的密切合作，法国，韩国，乌克兰。这项合作涉及来自亚利桑那大学、CNRS图卢兹、延世大学、首尔和基辅高分子化学研究所的聚合物化学家，以及来自美国能源部艾姆斯实验室和橡树岭国家实验室的软物质物理学家。与工业实验室的持续合作将加强这一活动，并将为研究生带来宝贵的经验。通过密集的外部合作，拟议的研究计划将使博士学位。学生成为成熟的，国际知名的研究人员熟悉尖端的基础和应用研究。 PI将通过几个招聘/保留计划，包括“学习和赚取计划”（即，招收大一材料学生），大一荣誉计划，妇女在科学和工程计划，BS/MS计划（招收高年级学生研究生课程），和REU计划。PI将继续强调招收妇女和少数民族学生，这是他相当成功的一个领域。 考虑到他的研究小组目前的组成，PI预计在未来三年内，他的学生中超过50%将是女性。 这将显着增加该群体的代表性，目前该群体不超过工程学院所有学生的15%。

The project addresses interfacial state of dendritic and branched molecules with various functionalized cores and branches such as amphiphilic monodendrons, branched discs, and hyperbranched polymers. The ultimate goal of this project is to understand the basic relationships in chemical architecture-interfacial organization-interfacial properties of novel dendritic and branched molecules with variable shape and symmetry of cores, degree and nature of branching, variable amphiphilic balance, and anchoring ability. For such molecules, surface anchoring can occur at well-defined single or multiple points. This anchoring should stabilize molecules on a surface but still allow enough mobility for the outer shell to form organized nanoassemblies with external functional groups. For such assembly, terminal groups of monodendron shell are completely exposed to external interactions. In further developing this concept, the previously explored selection will be expanded by including new types of molecules: disc-, rod-, and hair-pin branched amphiphiles, monodendrons with anchoring focal point, hetero-armed star-polymers, functionalized hyperbranches, and phosphor-organic dendrimers. This research will address several important questions: How does the chemical composition and symmetry of shape-persistent cores and flexible branches affect the balance of interfacial forces? What is an optimal balance for the formation of stable organized monolayers at the air-water interface and a solid surface? How is surface anchoring affected by the dendritic architecture? How do principles of chemically and electrostatically-driven self-assembly known for linear macromolecules, work in complex branched macromolecules? A broader impact includes fostering an intensive partnership between the PI's group and other researchers from science and engineering departments in the U.S., France, Korea, and Ukraine. This collaboration involves polymer chemists from University of Arizona, CNRS Toulouse, Yonsei University, Seoul, and the Institute of Macromolecular Chemistry, Kiev, as well as soft matter physicists from the DOE Ames Lab and Oak Ridge National Lab. Continuing collaboration with industrial labs will enhance this activity and will bring invaluable experience for graduate students. Through intensive external collaboration, the proposed research program will enable Ph.D. students to become mature, internationally aware researchers familiar with cutting-edge basic and applied research. The PI will focus his efforts to increase the number of students pursuing advanced degrees in science and engineering by working with several recruiting/retention programs, including "Learn and Earn Program" (i.e., recruiting freshman materials students), Freshman Honors Program, Women in Science and Engineering Program, BS/MS Program (recruitment of senior students to graduate program), and REU programs. The PI will continue his emphasis on recruiting women and minority students, an area in which he has been quite successful. Given the current composition of his research group, the PI expects that more than 50% of his students graduating within next three years will be women. This will be a significant increase in representation for the group that currently does not exceed 15% of all students in the engineering college.