A rotational magnetic-bearing rheometer for soft-materials characterization

一个最先进的旋转流变仪与磁浮轴承寻求提供流变学数据表征微观结构的水凝胶，分散体，溶液和纳米复合材料。该仪器使这些精致的材料进行精确的剪切变形，在稳定和振荡的强迫下，在控制应变速率和应变幅度的大范围内，在精确控制的温度下，提供剪切粘度和弹性模量。这些数据将用于推进纳米颗粒在水凝胶中传输的基本理论模型；例如，从测量的剪切模量中，我们可以了解到控制孔隙度和排水特性的交联密度。粘弹性特性也需要作为水凝胶动力学理论模型的输入数据和参数，这在生物传感器中很重要。该仪器将用于测试和验证内部微流变仪器，并为解释水凝胶-胶体复合材料的新型电声和光镊微电泳实验提供数据。最后，该仪器将用于确定废水污泥的剪切模量，为建立电渗透脱水预测理论模型提供关键信息；反过来，这种模式将有助于将节能的加拿大脱水处理技术推向全球水处理市场。该流变仪将通过加强基础和应用研究项目，促进能源、环境和人类健康应用，包括分子分离、干燥和消毒、微流体驱动、药物输送、纳米颗粒表征和生物传感，从而使加拿大的研究企业受益。

A state-of-the-art rotational rheometer with magnetically floating bearings is sought to furnish rheological data for characterizing the microstructure of hydrogels, dispersions, solutions, and nano-composites. The instrument subjects these delicate materials to precise shear deformations, furnishing the shear viscosity and elastic modulus under steady and oscillatory forcing, over a wide range of controlled strain rate and strain amplitudes, at a precisely controlled temperature. The data will be used to advance fundamental theoretical models of nanoparticle transport in hydrogels; e.g., from the measured shear modulus, we learn the cross-link density, which controls porosity and draining properties. The visco-elastic characteristics are also required as input data and parameters for theoretical models of hydrogel dynamics, which are important in biosensors. The instrument will be used to test and validate in-house microrheological instrumentation, and to furnish data to interpret novel electroacoustic and optical-tweezers microelectrophoresis experiments on hydrogel-colloid composites. Finally, the instrument will be used to ascertain the shear modulus of waste-water sludge, providing critical information with which to build a predictive theoretical model of electroosmotic dewatering; in turn, this model will help place an energy-efficient Canadian dewatering treatment technology in the global water-treatment market. The rheometer will benefit the Canadian research enterprise by strengthening a fundamental and applied research program that advances energy, environmental, and human health applications, including molecular separations, drying and disinfection, micro-fluidic actuation, drug delivery, nanoparticle characterization, and biosensing.