Direct visualization of flow-induced microstructure in dense colloidal gels by confocal laser scanning microscopy

被引:55
|
作者
Varadan, P [1 ]
Solomon, MJ [1 ]
机构
[1] Univ Michigan, Dept Chem Engn, Ann Arbor, MI 48109 USA
关键词
D O I
10.1122/1.1579689
中图分类号
O3 [力学];
学科分类号
08 ; 0801 ;
摘要
Unconstrained uniaxial compression (or squeeze flow) of high volume fraction gels of fluorescent silica particles of diameter 832 nm results in the formation of voids (at phi = 0.26) and cracks (at phi = 0.40) that are of scale 10-100 mum. This evidence of inhomogeneous material deformation was obtained by direction visualization of three-dimensional structure by confocal laser scanning microscopy. Flow-induced void and crack microstructures are quantified by locating all particle centroids with quantitative image processing, by performing Voronoi volume tessellation with computational geometry and by analyzing the particle number density fluctuations as a function of averaging volume. Average short-range real space structural measures, such as the pair correlation function, are little changed by the flow. However, the probability distribution of excess normalized Voronoi polyhedra volume is profoundly extended by squeeze flow, particularly at large polyhedra volumes. Comparison of the Voronoi polyhedra volume distributions and particle bond distributions. indicates that: (1) in the low 0 gel, large flow-induced voids are formed by the reorganization of the existing quiescent voids without significant effect on the local structure; and (2) in the high 0 gel, cracks are formed by reorganization of the local structure itself. Analysis of the number density. fluctuations shows that the gels respond to applied squeeze flow deformation with structural distortion on the length scale of 5-10 particle diameters. (C) 2003 The Society of Rheology.
引用
收藏
页码:943 / 968
页数:26
相关论文
共 50 条
  • [21] Diffusion of macromolecules in polymer solutions and gels: A laser scanning confocal microscopy study
    Burke, MD
    Park, JO
    Srinivasarao, M
    Khan, SA
    MACROMOLECULES, 2000, 33 (20) : 7500 - 7507
  • [22] Confocal laser scanning microscopy for optical measurement of the microstructure of surfaces and layers
    Kapitza, HG
    TECHNISCHES MESSEN, 1996, 63 (04): : 136 - 141
  • [23] Microstructure of buckwheat and barley during malting observed by confocal scanning laser microscopy and scanning electron microscopy
    Wijngaard, H. H.
    Renzetti, S.
    Arendt, E. K.
    JOURNAL OF THE INSTITUTE OF BREWING, 2007, 113 (01) : 34 - 41
  • [24] Characterization of coating microstructure using laser scanning confocal microscopy.
    Sung, LP
    Nadal, ME
    Stutzman, P
    McKnight, ME
    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 2000, 220 : U350 - U350
  • [25] Inhomogeneous distribution of charged colloidal particles studied by confocal laser scanning microscopy
    Ito, K
    Yoshida, H
    COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 2000, 174 (1-2) : 55 - 77
  • [26] Direct Visualization of Reversible Switching of Micropatterned Polyelectrolyte Brushes on Gold Surfaces Using Laser Scanning Confocal Microscopy
    Dai, Xiaowen
    Zhou, Feng
    Khan, Neelam
    Huck, Wilhelm T. S.
    Kaminski, Clemens F.
    LANGMUIR, 2008, 24 (22) : 13182 - 13185
  • [27] Visualization of filler network in silicone rubber with confocal laser-scanning microscopy
    Liu, Min
    Kang, Ming
    Mou, Yongren
    Chen, Kexu
    Sun, Rong
    RSC ADVANCES, 2017, 7 (84): : 53578 - 53586
  • [28] Visualization of nuclear pore complex and its distribution by confocal laser scanning microscopy
    Kubitscheck, U
    Kues, T
    Peters, R
    CONFOCAL MICROSCOPY, 1999, 307 : 207 - 230
  • [29] Visualization of carbon nanotubes dispersion in composite by using confocal laser scanning microscopy
    Danko, Martin (martin.danko@savba.sk), 1600, Elsevier Ltd (79):
  • [30] Visualization and quantification of polymer distribution in microcapsules by confocal laser scanning microscopy (CLSM)
    Lamprecht, A
    Schäfer, UF
    Lehr, CM
    INTERNATIONAL JOURNAL OF PHARMACEUTICS, 2000, 196 (02) : 223 - 226