Porcar L, Pozzo D, Langenbucher G, Moyer J, Butler P D
National Institute of Standards and Technology, Center for Neutron Research, Gaithersburg, Maryland 20899, USA.
Rev Sci Instrum. 2011 Aug;82(8):083902. doi: 10.1063/1.3609863.
We describe the design and operation of a modified commercial rheometer to simultaneously perform rheological measurements and structural studies by small angle neutron scattering (SANS). The apparatus uses a Couette geometry shear cell allowing two of the three scattering planes to be observed by performing experiments in either the radial or tangential geometries. The device enables small angle neutron scattering patterns to be obtained simultaneously with a wide variety of rheological measurements such as stress/strain flow curves, oscillatory deformations, and creep, recovery and relaxation tests, from -20 °C to 150 °C, for samples with viscosities varying by several orders of magnitude. We give a brief report of recent experiments performed on a dispersion of acicular nanoparticles and biopolymer network under stress demonstrating the utility of such measurements. This device has been developed at the National Institute of Standards and Technology's Center for Neutron Research (NCNR) and made available to the complex fluids community as part of the standard sample environment equipment.
我们描述了一种经过改进的商用流变仪的设计与操作，该流变仪能够通过小角中子散射（SANS）同时进行流变学测量和结构研究。该仪器采用库埃特几何形状的剪切池，通过在径向或切向几何形状中进行实验，可以观察到三个散射平面中的两个。该装置能够在 -20°C 至 150°C 的温度范围内，针对粘度变化达几个数量级的样品，同时获得小角中子散射图案以及各种流变学测量结果，如应力/应变流动曲线、振荡变形以及蠕变、恢复和松弛测试。我们简要报告了近期对针状纳米颗粒和生物聚合物网络在应力作用下的分散体进行的实验，证明了此类测量的实用性。该装置由美国国家标准与技术研究院中子研究中心（NCNR）开发，并作为标准样品环境设备的一部分提供给复杂流体研究领域。
