Career Program: Extensional Rheology of Polymer Solutions and Melts: Impact Processing

建议编号：9624293 PI：科林这个病房是一个综合的职业发展计划，旨在培养初中、高中、本科生和研究生在复杂流体的流变行为领域，并进行聚合物拉伸流变学的研究。这项研究将涉及四种不同的拉伸流变仪。这些流变仪将用于研究聚合物溶液在一定温度范围内的拉伸性能。这项研究的重点是确定表征粘弹性流体行为所需的性质。它将解决一系列问题，例如经历大Henky应变的聚合物的分子构象和稳态拉伸粘度是什么，以及现有的本构方程是否足以描述粘弹性流体的剪切和无剪切材料函数。这些信息对于许多聚合物加工操作，包括纤维纺丝、吹塑成型和注塑成型，以及各种其他现象，包括湍流减阻、射流稳定性、防雾和在多孔介质中流动，都是至关重要的。已经制定了一项雄心勃勃的教育计划。将进行演示，向学生介绍流变学和材料在日常使用中的行为之间的关系。例如，橡皮筋的弹性，粘弹性流体(如蛋糕面糊和炒鸡蛋)中的魏森伯格效应，洗发水的模胀，以及蛋黄酱和番茄酱中产生的屈服应力。PI计划与高中生合作开发科学博览会项目，并计划为对食品生物材料、胶体、乳液、泡沫、聚合物熔体、聚合物溶液、弹性体、复合材料、蜡和金属的流变学感兴趣的本科生和研究生开发一门跨学科课程和实验室经验。

ABSTRACT Proposal Number: 9624293 PI: Koelling This ward is for an integrated career development plan to educate junior high, senior high, undergraduate, and graduate students in the field of rheolgical behavior of complex fluids and conduct research on the extensional rheology of polymers. The research will involve four different extensional rheometers. These rheometers will be used to study the extensional properties of polymer solutions over a range a range of temperatures. This research is focused on determining the properties necessary to characterize the behavior of viscoelastic fluids. It will address a range of issues such as what is the molecular conformation and steady-state extensional viscosity of a polymer undergoing large Henky strains and whether existing constitutive equations are adequate for describing shear and shear-free material functions of viscoelastic fluids. This information is of fundamental importance to many polymer processing operations including fiber spinning, blow molding, and injection molding and in a variety of other phenomena including turbulent drag reduction, jet stability, anti-misting and flow through porous media. An ambitious educational plan has been formulated. Demonstrations will be developed to introduce students to the relationship between rheology and the behavior of materials in everyday use. Examples include elasticity of rubber bands, Weissenberg effects in viscoelastic fluids such as cake batter and scrambled eggs, die swell with shampoos and yield stresses developed in mayonnaise and ketchup. The PI plans to work with high school students in developing science fair projects and also plans to develop an interdisciplinary course and laboratory experience for both undergraduate and graduate students interested in the rheology of foods bio-materials, colloids, emulsions, foams, polymer melts, polymer solutions, elastomers, composites, waxes and metals.