RUI: Physico-Chemical Characterization and Processing of Nanocomposite Polymers for Microfluidic Applications.

聚合物-无机杂化材料代表了聚合物材料领域的一个重要发展，因为它有可能根据不同的化学成分和无机成分的百分比来定制这些材料的物理性质。这项本科院校研究（RUI）提案涉及几个领域的智力价值。本研究的主要技术目标是了解多面体低聚硅氧烷（POSS）基纳米复合聚合物材料在氧化或还原等离子体环境下的基本物理化学表面特性，以及它们在高温或紫外线照射下的长期稳定性。第二个目标是确定等离子体修饰的poss基聚合物是否可以用作改进的聚合物微流控装置的涂层材料。基于poss的聚合物表面的空间和化学成分的等离子体控制将使用远程等离子体处理工具来实现，并且将使用表面分析技术的组合来研究性能，包括x射线光电子能谱（XPS），原子和横向力显微镜（AFM/LFM），扫描电子显微镜（SEM）和接触角测量。基于pmma的微流体器件的测试设计已经完成，基于poss的薄膜将被沉积在这些器件上，以确定使用等离子体表面修饰的电渗流（EOF）特性的变化。表面的空间控制将通过微制造的阴影掩膜来完成，允许亲水性/疏水性梯度被图案化到微流体通道中。EOF和流体流动测量将与弗吉尼亚大学合作进行，以确定流体流动是否可以通过微流体结构内的空间调制表面来控制。进一步的目标是设计和开发一种集成的检测方法，使用紫外-可见吸收光谱法，利用PMMA的低吸收边缘，与微流控设备中通常使用的玻璃基板相比。与本提案更广泛影响相关的最终目标是在高度跨学科的研究环境中对本科研究生和高中科学教师进行科学培训。该项目将在项目期间培训6至10名本科生研究人员和3名高中化学、物理或生物教师。在这两种情况下，本项目将向本科化学和物理学生以及中学教师介绍结构-性质关系的材料科学问题。学生和老师都将接触到表面分析技术，真空科学，高分子材料表征和加工，以及微流体技术和科学。该项目的参与者还将通过直接的实验室接触与弗吉尼亚大学的研究生和博士后研究人员互动，以体验研究机构的研究。这些活动有助于广泛地影响从高中到研究生阶段的未来科学家队伍。

Hybrid polymer-inorganic materials represent an important development in the polymermaterials field due to the ability to potentially tailor the physical properties of these materialswith varying chemical composition and percentage of the inorganic component. This Research atUndergraduate Institutions (RUI) proposal addresses several areas of intellectual merit. Theprimary technical objective of this study is to understand the fundamental physicochemicalsurface properties of polyhedral oligomeric silsesquioxane (POSS)-based nanocompositepolymer materials when modified by oxidizing or reducing plasma environments, and their longtermstability at elevated temperatures or with ultraviolet light exposure. A second objective is todetermine whether plasma-modified POSS-based polymers can be used as a coating material forimproved polymer microfluidic devices. Plasma control of the spatial and chemical compositionof the POSS-based polymer surface will be achieved using a remote plasma treatment tool andthe properties will be studied using a combination of surface analysis techniques including x-rayphotoelectron spectroscopy (XPS), atomic and lateral force microscopy (AFM/LFM), scanningelectron microscopy (SEM), and contact angle measurements. Test designs for PMMA-basedmicrofluidic devices have been fabricated, and POSS-based thin films will be deposited ontothese to determine the change in electroosmotic flow (EOF) characteristics using plasma surfacemodification. Spatial control of the surface will be accomplished through a microfabricatedshadow mask allowing for a hydrophilic / hydrophobic gradient to be patterned into themicrofluidic channel. EOF and fluid flow measurements will be made in collaboration with theUniversity of Virginia to determine whether fluid flow can be controlled through a spatiallymodulated surface within a microfluidic structure. A further objective is to design and developan integrated detection methodology for microfluidic devices using ultraviolet-visible absorptionspectroscopy taking advantage of the lower absorption edge of PMMA compared to the glasssubstrates typically used in microfluidic devices.A final objective related to the broader impacts of this proposal is the scientific training ofundergraduate research students and high school science teachers in a highly interdisciplinaryresearch environment. This project will involve the training of six to ten undergraduateresearchers and three high school chemistry, physics or biology teachers over the duration of theprogram. In both cases, this project will introduce undergraduate chemistry and physics studentsand secondary school teachers to the materials science issues of structure-property relationships.Both students and teachers will be exposed to surface analytical techniques, vacuum science,polymer materials characterization and processing, and microfluidic technology and science. Theparticipants in this program will also interact with graduate students and post-doctoralresearchers at the University of Virginia through direct laboratory exposure in order toexperience research at a research institution. These activities help serve to broadly impact thepipeline of future scientists from the high school through the graduate level.