Mixed Rod-Coil Polymer Brushes Tailored for Controlled Surface Topography

专为受控表面形貌而定制的混合棒线圈聚合物刷

• 批准号: 1905403
• 负责人: Yu Zhong
• 金额: $ 75万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905403&HistoricalAwards=false
• 关键词: Mixed; Rod; Coil; Polymer; Brushes

PART 1: NON-TECHNICAL SUMMARY: Polymers are long molecules that make up the many kinds of coatings, fabrics and plastics we use. Some polymers can be flexible and soft. Other polymers can be long and stiff. By combining stiff and flexible polymers in a single system formed on a surface, we have learned that we can make nanoscale spiky brush-like surfaces using careful temperature control and coating methods. The PI and his group plan to better understand this surface formation process by making new combinations of soft and stiff polymers, by using advanced tools to study their organization, and by employing computers to model the structure and to predict their behavior. This new way of making surfaces opens up many interesting applications. For example, the surface mimics the protein spikes present on virus surfaces that are used by nature to identify target cells, take part in the entry into the cell, and also to prevent identification by antibodies. These materials can be used to study the behavior of cells on topics ranging from how they work to the behavior of the immune system. Because the spikes are vertically aligned, they may also act as nanowires, so they can be used in energy production and storage systems like solar cells and batteries. Finally, these spikes may be piezoelectric, i.e. they could convert electrical energy to motion (or sound) and motion to electrical energy. This research program will also serve as a mechanism to teach students about polymers and materials science, create globally aware graduate students, and expose students to a collaborative environment. Graduate students will be able to work with the research groups of our collaborators as parts of teams and to take part in exchange visits. Lessons learned from these research programs will be used to teach K-12 students and to be applied in high school teachers' workshops. PART 2: TECHNICAL SUMMARY:Coil polymer brushes synthesized using living radical polymerization methods will be combined with rod brushes with high persistence lengths grown from surfaces made using a variety of living and pseudo-living chemistries. Phase separation aided by solvent processing and guided by nanolithography will be used to control in-plane structure. A variety of chemical and process methods will be used to limit macroscopic phase separation and thereby direct assembly of topographical and chemical structures. Brush growth will employ new, chemically tailored brush initiators for single chain and binary chain growth to form rod-coil mixed brush pairings. To direct brush structure and rod-coil phase separation, brush initiators will be patterned at length scales of a few 10s of nanometers using state-of-the-art lithography methods to control spacing of the brush spikes. Brush organization will be compared to computational predictions which will be used to guide both brush design and selection and to anticipate the resulting physical structure and aid characterization studies. Characterization of the brushes will be made using a selection of analytical methods including grazing incidence (GI) SAXS and WAXS, neutron reflectivity and resonant soft X-ray scattering (RSoXS) measurements. Studies of the conductivity and piezoelectric character of the rod-coil brush films will aid in our understanding of the mixed brush structure. Through collaborations, studies of these materials as cell membrane substrates, for targeted biomolecular binding, as piezoelectric and as conducting materials with unusual transport pathways, will also provide information about key length scales and rod-brush organization. .This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

第一部分： 非技术性总结：聚合物是长分子，构成了我们使用的多种涂料、织物和塑料。一些聚合物可以是柔性和柔软的。其他聚合物可以是长的和硬的。通过将刚性和柔性聚合物结合在一个表面上形成的单一系统中，我们已经了解到，我们可以使用仔细的温度控制和涂层方法来制造纳米级的尖锐刷状表面。PI和他的团队计划通过制造软聚合物和硬聚合物的新组合、使用先进工具研究其组织以及使用计算机对结构进行建模并预测其行为来更好地了解这种表面形成过程。这种制作曲面的新方法开辟了许多有趣的应用。例如，该表面模拟病毒表面上存在的蛋白质刺突，这些蛋白质刺突在自然界中用于识别靶细胞，参与进入细胞，并且还用于防止抗体识别。这些材料可用于研究细胞的行为，从它们如何工作到免疫系统的行为。由于尖峰是垂直排列的，它们也可以充当纳米线，因此它们可以用于太阳能电池和电池等能源生产和存储系统。最后，这些尖峰可以是压电的，即它们可以将电能转换为运动（或声音），并将运动转换为电能。该研究计划还将作为一种机制，向学生传授聚合物和材料科学，培养具有全球意识的研究生，并使学生接触到协作环境。研究生将能够与我们的合作者的研究小组作为团队的一部分，并参加交流访问。从这些研究项目中吸取的经验教训将用于教授K-12学生，并应用于高中教师研讨会。第二部分： 技术总结：使用活性自由基聚合方法合成的卷曲聚合物刷将与从使用各种活性和伪活性化学物质制成的表面生长的具有高持久性长度的棒刷组合。溶剂处理辅助和纳米光刻引导的相分离将用于控制面内结构。将使用各种化学和工艺方法来限制宏观相分离，从而直接组装形貌和化学结构。刷增长将采用新的，化学定制的刷引发剂的单链和二元链的增长，形成棒-线圈混合刷配对。为了直接刷结构和棒-线圈相分离，将使用最先进的光刻方法以几十纳米的长度尺度图案化刷引发剂以控制刷尖的间距。将刷子组织与计算预测进行比较，计算预测将用于指导刷子设计和选择，并预测产生的物理结构和辅助表征研究。刷子的表征将使用一系列分析方法，包括掠入射（GI）SAXS和WAXS，中子反射率和共振软X射线散射（RSoXS）测量。对棒-线圈刷膜的导电性和压电特性的研究将有助于我们对混合刷结构的理解。通过合作，研究这些材料作为细胞膜基底，用于靶向生物分子结合，作为压电材料和具有不寻常运输途径的导电材料，还将提供有关关键长度尺度和杆刷组织的信息。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Using Liquid Crystals to Probe the Organization of Helical Polypeptide Brushes Induced by Solvent Pretreatment

利用液晶探测溶剂预处理诱导的螺旋多肽刷的组织

• DOI: 10.1021/acs.macromol.1c01125
• 发表时间: 2021
• 期刊: Macromolecules
• 影响因子: 5.5
• 作者: Tsuei, Michael;Tran, Hai;Roh, Sangchul;Ober, Christopher K.;Abbott, Nicholas L.
• 通讯作者: Abbott, Nicholas L.