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

点击翻译按钮获取中文摘要

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.