Precision Monolayer Chemistry on Amorphous Materials

在化学系大分子，超分子和纳米化学（MSN）计划的支持下，普渡大学的Shelley Claridge正在研究基本过程，这些过程可以精确控制技术上重要的非晶材料的表面化学。如果能更好地理解这些过程，就能设计和制造具有明确化学指令的表面，这些指令适用于从组装太阳能转换材料到支撑细胞生长以修复损伤的材料等过程。在该项目中，将使用专用显微镜监测一类表面反应的进展，这些显微镜能够在单个分子的尺度上成像。这些信息与包括荧光显微镜在内的大规模实验技术相结合，提供了反应过程的分子到宏观视图。 作为该项目的一部分，克拉里奇博士正在与她的研究小组的研究生和少数民族服务的本科院校合作，开发一系列教育经验和资源，帮助本科生分析和交流科学发现，作为他们未来科学事业的基础。 该项目利用已知在石墨和其他二维材料上组装的功能性烷基二乙炔的条纹相，作为使无定形弹性体材料（如聚二甲基硅氧烷（PDMS））表面官能化的基础，所述无定形弹性体材料表现出显著的纳米级异质性。在这种策略中，二乙炔单体组装在石墨上，通过紫外光照射进行光聚合，然后使用硅氢加成反应共价转移到PDMS表面，硅氢加成反应是PDMS固化的基础。该项目的前两个目的是了解二乙炔单体结构和条纹相单层聚合效率之间的关系，并了解PDMS组分结构（乙烯基官能基聚合物和交联剂中的氢化硅烷基基团）和与条纹聚二乙炔层的反应性之间的关系。该过程的最后阶段基于其控制各向同性和各向异性颗粒吸附的能力来表征PDMS上的单层的功能。对条纹相聚二乙炔聚合反应、转移反应和表面功能的理解和控制，有可能使表面带有嵌入式化学指令，用于可穿戴电子产品、色谱和细胞培养等应用。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

With support from the Macromolecular, Supramolecular, and Nanochemistry (MSN) Program in the Division of Chemistry, Shelley Claridge at Purdue University is studying fundamental processes that allow precise control over the surface chemistry of technologically important amorphous materials. If better understood, these processes could enable design and fabrication of surfaces with well-defined chemical instructions for processes ranging from the assembly of materials for solar energy conversion to materials that scaffold the growth of cells to repair injuries. In this project, the progress of a class of surface reactions will be monitored using specialized microscopes that enable imaging at the scale of individual molecules. This information is integrated with larger-scale experimental techniques including fluorescence microscopy, providing a molecular-to-a macroscopic view of the reaction progress. As part of this project, Dr. Claridge is working with graduate students in her research group and with minority-serving undergraduate institutions to develop a series of educational experiences and resources that help undergraduate students analyze and communicate scientific findings, as a foundation for their future careers in science. This project utilizes striped phases of functional alkyl diacetylenes known to assemble on graphite and other two-dimensional materials as a basis for functionalizing the surface of amorphous elastomeric materials such as polydimethylsiloxane (PDMS) that exhibit substantial nanoscale heterogeneity. In this strategy, the diacetylene monomers are assembled on graphite, photo-polymerized by irradiation with ultraviolet light, then covalently transferred to the PDMS surface using the hydrosilylation reaction that is the basis for PDMS curing. The first two aims of this project are to understand the relationship between diacetylene monomer structure and striped phase monolayer polymerization efficiency, and to understand the relationship between PDMS component structure (vinyl-functional base polymer and hydrosilyl groups in crosslinker) and reactivity with the striped polydiacetylene layer. The final stage of the process characterizes the function of monolayers on PDMS based on their ability to control isotropic and anisotropic particle adsorption. Understanding and control of the striped phase polydiacetylene polymerization reaction, transfer reaction, and surface functionality has to the potential to lead to surfaces that carry embedded chemical instructions for applications including wearable electronics, chromatography, and cell culture.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.