Dynamics of Phase Separating Thin Film Blends

9974366 Composto拟议的研究将集中在相分离薄膜共混物的动力学。 这些研究的目的是通过测量在空气/聚合物和聚合物/基材界面的润湿层生长，润湿层下面的相形态，域粗化，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的函数进行研究，包括分子量和成分，工艺相关变量，包括膜厚度和温度，以及基板表面能。 为了测试通用行为，将研究一系列模型共混物系统，包括具有较低临界溶解温度和较高临界溶解温度的共混物以及共聚物共混物。 为了直接测试相分离和润湿之间的相互作用，AFM将用于在润湿相的选择性蚀刻之后直接对近表面形态进行成像。 润湿层的生长将使用低能量，前向反冲光谱，LE-FRES，和中子反射率。 此外，LE-FRES将被开发用于横向非均匀样品的分析。 为了量化弯曲界面处的横向相组成和可能的界面宽度，将在内部开发分析TEM，并与NIST合作进行近边缘X射线吸收精细结构光谱。 除了均匀的基材外，研究还旨在控制横向轮廓研究，将使用接触角测角仪和AFM测量润湿性能。 该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物粘合促进剂和图案化介电材料的先进材料。该研究将提供对聚合物薄膜和涂层的基础科学理解，可能会影响健康（例如隐形眼镜，膜）和微电子（例如光刻胶和抗蚀剂）领域的先进技术应用。 本科生（4/年）将继续参加研究计划，沿着公立高中教师在夏季。

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.