Patterned Polymer Brushes as the Basis of Shape Selected Molecular Objects

图案化聚合物刷作为选定分子物体形状的基础

• 批准号: 1105253
• 负责人: Christopher Ober
• 金额: $ 58万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1105253&HistoricalAwards=false
• 关键词: Patterned; Polymer; Brushes; Basis; Shape

TECHNICAL SUMMARY:This research program will examine the synthesis, characterization and lithographic processing of "grown from" di- and triblock copolymer brushes. By combining brush growth and self-assembly with precision patterning a variety of new polymer micro- and nanostructures will be created that are not easily produced by other means. A key aspect of the proposed research is a focus on immiscible block segment combinations that react in opposite ways to the radiation used during lithographic patterning. By using one phase that crosslinks and one that is scissioned (and easily removed), new periodic structures, porous materials, brush membranes, nanosheets and nanoribbons will be formed. Through brush growth the composition and height will be set and through patterning lateral size and shape will be determined. Advanced patterning methods will initially include electron beam techniques and will subsequently involve deep UV processes. In order to speed evaluation of brush architecture and its effect on pattern formation, the use of initiator density gradients and brush segment size gradients will be employed. Mixed brushes, binary brushes and block copolymer brushes consisting of crosslinkable and scissionable segments will be investigated. Characterization of the brushes before and after patterning will be made using a variety of analytical tools including X-ray reflectometry, grazing incidence (GI) SAXS and WAXS, neutron reflectivity and near edge X-ray absorption fine structure (NEXAFS) measurements. Each technique will provide information about the internal or surface organization of the material and will aid our understanding of the structures produced. Neutron reflectivity in particular will provide information about the brush chain conformation as the brush undergoes the patterning process. Several model systems will be investigated to better understand the process limitations and the possible architectures that can be produced from these brushes. Mixed gradient brushes, supported membranes and untethered nanosheets and nanoribbons will be explored. It is anticipated that applications for these brushes will include new membranes for water purification, nanochannels for small-scale fluidic devices and new nanopatterned strucures from brush gradients. NON-TECHNICAL SUMMARY:Polymer brushes are ideal structures to interface the surface of a material with its environment. Like many natural surfaces, polymer chains extend from a surface and provide an organic coating with functional groups that can be modified or used in a number of applications. Along with systematic synthesis and characterization of these materials, there are prospects for making brush surfaces with gradient controlled properties, nanosheets with the ability to wrap drugs and other useful materials for later release, new membranes for water purification to help better improve drinking water in arid regions and nanochannels that will enable transport of fluids in small devices such as sensors. The research program will act as a mechanism to engage undergraduates in polymer science and materials research. Graduate students will serve as mentors and role models to these young students, while at the same time gaining supervisory skills. Graduate students will have an opportunity to work with the research groups of our collaborators and to take part in exchange visits. Undergraduates from Cornell will take part during the academic year while REU students from other schools with an emphasis on underrepresented students will participate in research during the summer months. Cornell undergraduates taking part in this program will be encouraged to take internships at the companies and university labs we will interact with. Lessons learned from these research programs will be factored into programs in which the PI and graduate student volunteers interact with high school teachers. Patterned brushes make interesting visual aids because hydrophobic brushes can repel water. Sample brushes on substrates will be made available to interested teachers the PI will meet at teacher workshops offered by Cornell.

技术摘要：该研究计划将研究“由”二嵌段和三嵌段共聚物刷“生长”的合成、表征和光刻加工。通过将刷子生长和自组装与精密图案相结合，将创建各种新的聚合物微米和纳米结构，这是其他方法不易生产的。拟议研究的一个关键方面是关注不混溶的块段组合，这些组合以与光刻图案化过程中使用的辐射相反的方式发生反应。通过使用一种可交联的相和一种可分裂（且易于去除）的相，将形成新的周期性结构、多孔材料、刷膜、纳米片和纳米带。通过画笔生长，将设置构图和高度，并通过图案化确定横向尺寸和形状。先进的图案化方法最初将包括电子束技术，随后将涉及深紫外工艺。为了加速评估刷子结构及其对图案形成的影响，将采用引发剂密度梯度和刷子段尺寸梯度。将研究由可交联和可断裂链段组成的混合刷、二元刷和嵌段共聚物刷。将使用各种分析工具对图案化前后的刷子进行表征，包括 X 射线反射计、掠入射 (GI) SAXS 和 WAXS、中子反射率和近边缘 X 射线吸收精细结构 (NEXAFS) 测量。每种技术都将提供有关材料内部或表面组织的信息，并有助于我们理解所产生的结构。当刷子经历图案化过程时，中子反射率尤其会提供有关刷子链构象的信息。将研究几个模型系统，以更好地了解工艺限制以及可以从这些画笔产生的可能架构。将探索混合梯度刷、支撑膜以及不受束缚的纳米片和纳米带。预计这些刷子的应用将包括用于水净化的新型膜、用于小型流体装置的纳米通道以及来自刷子梯度的新型纳米图案结构。非技术摘要：聚合物刷是连接材料表面与其环境的理想结构。 与许多天然表面一样，聚合物链从表面延伸并提供带有官能团的有机涂层，该官能团可以在多种应用中进行改性或使用。 除了这些材料的系统合成和表征之外，还有望制造具有梯度控制特性的刷子表面、能够包裹药物和其他有用材料以便稍后释放的纳米片、用于水净化的新膜以帮助更好地改善干旱地区的饮用水，以及使传感器等小型设备中的流体传输成为可能的纳米通道。该研究计划将作为一种机制，吸引本科生参与聚合物科学和材料研究。研究生将成为这些年轻学生的导师和榜样，同时获得监督技能。研究生将有机会与我们合作者的研究小组合作并参加交流访问。康奈尔大学的本科生将在学年期间参与研究，而其他学校的 REU 学生（重点是代表性不足的学生）将在夏季参与研究。我们将鼓励参加该计划的康奈尔大学本科生在我们将与之互动的公司和大学实验室实习。从这些研究项目中吸取的经验教训将被纳入 PI 和研究生志愿者与高中教师互动的项目中。有图案的刷子可以成为有趣的视觉辅助工具，因为疏水性刷子可以防水。 PI 将在康奈尔大学举办的教师研讨会上与感兴趣的教师见面，向感兴趣的教师提供基材上的刷子样本。