Determination of the shear modulus of colloidal solids with high accuracy
Determination of the shear modulus of colloidal solids with high accuracy
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DOI：
10.1051/jp3:1994139
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发表时间：
1994-03
期刊：
影响因子：
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通讯作者：
T. Palberg;Johannes Kottal;Tobias Loga;H. Hecht;E. Simnacher;F. Falcoz;P. Leiderer
中科院分区：
文献类型：
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作者：
T. Palberg;Johannes Kottal;Tobias Loga;H. Hecht;E. Simnacher;F. Falcoz;P. Leiderer
我们报告高精度和精密度测量的胶体固体的剪切模量形成的单分散带电乳胶球包含在电解质水溶液中。采用标准的结晶技术和最近报道的先进的去离子方法，在精确控制低体积分数~ P0.003和盐浓度~ c，w ~ 2 ~mol l~ 1的条件下制备了透明的体心立方晶体样品。在实验条件不变的情况下，通过控制凝固和进一步剪切处理，制备了不同形貌的样品。用各种静态光散射方法分析了它们的结构、织构和形貌。本文介绍了一种新的、无损的、时间分辨的静态光散射技术，用于检测圆柱形样品内激发的共振扭转振动。从谱图中计算了剪切模量与电解质浓度的关系，并对几种样品的形貌进行了比较。第一次实现了足够高的rewlution，以清楚地区分样品的形态和实验参数的影响。我们讨论了这种高精度测量胶体晶体剪切模量的新方法在广泛的有趣实验中的可能应用。
We report high accuracy and precision measurements of the shear modulus of colloidal solids formed from monodisperse charged latex spheres contained in an aqueous electrolyte. Standard preparational techniques as well as a recently reported advanced deionization method are applied to prepare transparent, bcc-crystalline samples at precisely controlled low volume fractions ~P 0.003 and salt concentration~ c, w 2 ~mol l~ ' The experimental parameters are found to be e~tremely stable if certain precautious mea~ures are taken. At constant experimental conditions samples of different morphologies are prepared via controlled solidifica- tion and further shear proces~ing. Their ,tructure, texture and morphology are analysed by various ~tatic light ~cattering methods. A new, non destructive, time resolved static light scattering technique is u~ed to detect the resonant torsional vibrations excited within a cylindrical sample. Shear moduli in dependence on the concentration of excess electrolyte are calculated from the rewnance spectra and compared for ~everal sample morphologies. For the first time a sufficiently high rewlution is achieved to clearly discriminate between the influence of the morphology of the sample and of the experimental parameters. We discuss the possible application~ of this new approach of'high accuracy shear modulus measurements in colloidal crystal~ to a wide range of interesting experiments.