Translational and rotational dynamics of colloidal rods by direct visualization with confocal microscopy

@article{citeulike:1683144, abstract = {We report an experimental method to characterize the dynamics of colloidal rods by measuring their rotation and translation in three dimensions with confocal microscopy. The method relies on solvent viscosification to retard dynamics to time scales that are compatible with 3D confocal optical microscopy. Because the method yields a full three-dimensional characterization of rod displacement and orientation, it is applicable to situations in which complex, anisotropic dynamics emerge. Examples include behavior in liquid crystal phases with both orientational and positional order, suspensions subjected to applied fields such as shear flow or sedimentation, and the emerging area of anisotropic particle dynamics. We demonstrate the performance of the method by quantifying the Brownian motion of fluorescent poly(methyl methacrylate) rods (aspect ratio, L/D=3.1 and 7.0) grafted with poly(dimethylsiloxane) stabilizer. The rods are dispersed at dilute concentration in a solvent mixture of viscosity 2.0 Pa[thin space]s. Rod translational and rotational diffusivities are extracted from the measured translational mean square displacement of the centroid positions and of the rod unit vector u(t), respectively. Rod orientational dynamics are characterized relative to both their azimuthal and polar angles. Probability distributions for the translation and rotation in the frame of rod are computed from the measurements. Experimental values obtained agree well with theory available for the dynamics of isolated rods.}, author = {Mukhija, Deshpremy and Solomon, Michael J. }, citeulike-article-id = {1683144}, doi = {10.1016/j.jcis.2007.05.055}, journal = {Journal of Colloid and Interface Science}, keywords = {colloidal, diffusion, microscopy, rotation}, month = {October}, number = {1}, pages = {98--106}, posted-at = {2008-05-11 00:08:56}, priority = {4}, title = {Translational and rotational dynamics of colloidal rods by direct visualization with confocal microscopy}, url = {http://dx.doi.org/10.1016/j.jcis.2007.05.055}, volume = {314}, year = {2007} }

TY - JOUR ID - citeulike:1683144 L3 - citeulike-article-id:1683144 TI - Translational and rotational dynamics of colloidal rods by direct visualization with confocal microscopy JF - Journal of Colloid and Interface Science VL - 314 IS - 1 SP - 98 EP - 106 N2 - We report an experimental method to characterize the dynamics of colloidal rods by measuring their rotation and translation in three dimensions with confocal microscopy. The method relies on solvent viscosification to retard dynamics to time scales that are compatible with 3D confocal optical microscopy. Because the method yields a full three-dimensional characterization of rod displacement and orientation, it is applicable to situations in which complex, anisotropic dynamics emerge. Examples include behavior in liquid crystal phases with both orientational and positional order, suspensions subjected to applied fields such as shear flow or sedimentation, and the emerging area of anisotropic particle dynamics. We demonstrate the performance of the method by quantifying the Brownian motion of fluorescent poly(methyl methacrylate) rods (aspect ratio, L/D=3.1 and 7.0) grafted with poly(dimethylsiloxane) stabilizer. The rods are dispersed at dilute concentration in a solvent mixture of viscosity 2.0 Pa[thin space]s. Rod translational and rotational diffusivities are extracted from the measured translational mean square displacement of the centroid positions and of the rod unit vector u(t), respectively. Rod orientational dynamics are characterized relative to both their azimuthal and polar angles. Probability distributions for the translation and rotation in the frame of rod are computed from the measurements. Experimental values obtained agree well with theory available for the dynamics of isolated rods. KW - colloidal KW - diffusion KW - microscopy KW - rotation AU - Mukhija, Deshpremy AU - Solomon, Michael PY - 2007/10/01/ UR - http://dx.doi.org/10.1016/j.jcis.2007.05.055 ER -