Engineering Research Equipment Grant: Low Angle Light Scattering Photometer

技术摘要：通过本研究设备拨款，低角度光散射光度计将有助于为一些研究项目提供所需的信息。其中包括：1)准确测定新型光刻胶聚合物的分子量和分子量分布。这些聚合物用于硅片上集成电路的生产，其性能受其分子量的影响。共聚物在电子轰击下发生高产量的断链反应，其结构、分子量和分布都将得到优化。ii)聚合物-聚合物混合物中的相容性和扩散研究。相容性混合物的可用性应扩大热塑性塑料的性能和可加工性的范围。研究了相分离曲线（温度变化）对两种聚合物相互扩散的影响。iii)聚合物与溶剂相互作用参数的测定。在一项正在进行的微凝胶性质研究中，低角度光散射光度计提供了亲水凝胶膨胀特性中起主要作用的分子量和相互作用参数的信息。胶体颗粒的聚集及其与陶瓷加工的关系。认为溶液衍生材料的固相性能取决于其在固相中的聚集状态。聚集动力学、溶胶-凝胶转化、组成和聚合物添加剂的影响都可以通过总强度散射间接监测，这是对目前正在研究的其他技术的补充。创新/创造力：光度计的用途之一是表征新的光刻胶系统。其目的是生产具有增强灵敏度，分辨率和耐蚀刻性的新系统，而不会失去聚甲基丙烯酸甲酯（标准光刻胶）多年来所显示的附着力，耐用性，可重复性和多功能性的固有优势。在相容性聚合物-聚合物混合物领域，若干实验室正在进行扩散系数测量方面的重大努力。然而，关于扩散的聚合物分子的大小，很少或根本没有收集到信息。用光散射光度计获得的互补总强度测量将提供迄今无法获得的尺寸和扩散系数之间的重要浓度。聚合物-溶剂相互作用对凝胶和微凝胶的溶胀特性起着至关重要的作用，聚合物-溶剂相互作用的表征可以很容易地从总强度散射的齐姆图中确定。这些信息是开发凝胶和微凝胶性质分类的一般框架的重要组成部分。最后，在胶体悬浮液领域，利用总散射光强度来监测聚合物添加剂对悬浮液稳定性、氧化铝涂层（如二氧化硅）沉积和醇盐凝胶溶胶-凝胶转化的影响。

Technical Abstract: By means of this research equipment grant, a low angle light scattering photometer will help provide needed information in a number of research projects. Some of these include: i) Accurate determination of molecular weight and molecular weight distribution of novel photoresist polymers. These polymers are used in the production of integrated circuits on silicon chips and their properties are affected by their molecular weight. Copolymers which undergo chain scission with high yields when bombarded by electrons will be optimized with regard to their structure, molecular weight, and distribution. ii) A study of the compatibility and diffusion in polymer-polymer mixtures. The availability of compatible mixtures should wident the range of the properties and processability of thermoplastics. The effect of the approach to the phase separation curve (by temperature changes) on the interdiffusion of the two polymers is examined. iii) Determination of the interaction parameters of polymers with solvents. In a study of the properties of microgels underway, the low angle light scattering photometer provides information on both molecular weights and interaction parameters that play a major role in the swelling properties of hydrophilic gels. iv) Aggregation of colloidal particles and its relevance to ceramic processing. It is believed that the solid state properties of solution derived materials depend on the state of aggregation in the solution phase. Aggregation kinetics, sol-gel transformation, the effect of composition and polymer additives can all be indirectly monitored by total intensity scattering which complement other techniques being presently pursued. Innovation/Creativity: One of the uses of the photometer is the characterization of new photoresist systems. The aim is to produce new systems with enhanced sensitivity, resolution, and etch resistance without losing the inherent advantages of adhesion, durability, reproducibility, and versatility which poly(methyl methacrylate) (the standard photoresist) has shown over the years. In the area of compatible polymer-polymer mixtures, major efforts are being undertaken in a number of laboratories in the measurements of diffusion coefficients. Very little or no information is being gathered, however, on the size of the diffusing polymer molecules. Complementary total intensity measurements to be obtained with the light scattering photometer will provide important concentrations between size and diffusion coefficient hitherto unavailable. The characterization of polymer-solvent interaction which plays a crucial role in the swelling characteristics of gels and microgels can be readily determined from a Zimm-plot of total intensity scattering. This information is an important ingredient in developing a general framework for the classification of the properties of gels and microgels. Finally in the area of colloidal suspensions, total scattered light intensity is used to monitor the effect of polymer additives on the stability of the suspensions, the deposition of a coating (e.g. silica) on alumina and the sol-gel transformation of alkoxide gels.