Dynamics of Phase Separating Thin Film Blends

9974366组分拟议的研究将重点放在相分离薄膜混合的动力学上。这些研究旨在通过测量空气/聚合物和聚合物/基材界面上的润湿层生长、润湿层下方的相形态、磁区粗化、表面粗糙度以及湿相和非湿相之间的粗糙度，来全面了解薄膜动力学。为了探索基本原理，动力学将作为材料参数(包括分子量和组成)、工艺相关变量(包括薄膜厚度和温度)以及衬底表面能的函数进行研究。为了测试通用行为，除了共聚共混物之外，还将研究一系列模型共混体系，包括具有较低临界溶液温度和较高临界溶液温度的共混物。为了直接测试相分离和润湿之间的相互作用，将使用原子力显微镜直接成像润湿相选择性刻蚀后的近表面形貌。将使用低能量、正反冲光谱、LE-FRES和中子反射率来跟踪润湿层的生长。此外，还将开发LE-FRES用于横向不均匀样品的分析。为了量化横向相组成和可能的弯曲界面处的界面宽度，将在内部开发分析性透射电子显微镜，并将与NIST合作进行近边X射线吸收精细结构光谱。除了均匀的衬底，研究的目标将是控制侧向轮廓研究，润湿性能将使用接触角测角仪和原子力显微镜进行测量。拟议研究的一个重要组成部分是将模型系统的基础研究扩展到涉及离聚体附着力促进剂和图案化介电材料的先进材料。拟议的聚合物薄膜和涂层研究将提供基本的科学理解，可能影响健康(例如隐形眼镜、薄膜)和微电子(例如介电和抗蚀剂)领域的先进技术应用。本科生(每年4人)将在暑假期间继续与公立高中教师一起参加研究计划。

9974366CompostoThe proposed research will focus on the dynamics of phase separating thin film blends. These studies aim to develop a comprehensive understanding of thin film kinetics by measuring the wetting layer growth at both the air / polymer and polymer / substrate interfaces, phase morphology immediately beneath the wetting layer, domain coarsening, surface roughness, and the roughness between the wet and non-wet phases. To probe underlying principles, dynamics will be studied as a function of materials parameters including molecular weight and composition, process dependent variables including film thickness and temperature, and substrate surface energy. To test for universal behavior, a range of model blend systems will be investigated including blends with a lower critical solution temperature and an upper critical solution temperature, in addition to copolymer blends. To directly test the interplay between phase separation and wetting, AFM will be used to directly image the near-surface morphology after selective etching of the wetting phase. Wetting layer growth will be followed using low-energy, forward recoil spectrometry, LE-FRES, and neutron reflectivity. Furthermore, LE-FRES will be developed for the analysis of laterally non-uniform samples. To quantify lateral phase composition and possibly the interfacial width at curved interfaces, analytical TEM will be developed in-house and near edge x-ray adsorption fine structure spectroscopy will be performed in collaboration with NIST. In addition to homogeneous substrates, studies will aim to control lateral profiling studies, wetting properties will be measured using a contact angle goniometer and AFM. An important component of the proposed research is to extend fundamental studies on model systems to advanced materials involving ionomer adhesion promoters and patterned dielectric materials.The proposed research on polymer films and coatings will provide fundamental scientific understanding that could impact advanced technological applications in the health (e.g. contact lenses, membranes) and microelectronics (e.g. dielectrics and resists) fields. Undergraduates (4/year) will continue to participate in the research program, along with public high-school teachers during the summer.