There has been strong experimental evidence that molecules of some dyes in an anisotropic solvent, nematic liquid crystal, form aggregates. We present a detailed experimental analysis of the light-induced director reorientation (DR) in a dye-doped nematic liquid crystal (known as the Jánossy effect) and a theoretical model of its strong enhancement based on the aggregates' interaction. The DR transition is found to be very different from the Frederiks effect.
View Article and Find Full Text PDFHere we report a study of chain formation and the magnetic anisotropy induced by them in suspensions of slightly anisotropic FeO nanoparticles in water and in aqueous VO suspensions. An investigation into the magnetization of the fluid and frozen suspensions, the application of dynamic light scattering techniques and the observation of the magnetic anisotropy in the frozen magnetically aligned samples allowed us to confirm the existence of chains of FeO in both suspensions. Our study shows that the magneto-induced anisotropy appearing in magnetic fields in colloids with FeO particles is mainly due to many particle (chain) magneto-induced anisotropy, but not due to single particle magneto-induced anisotropy connected with particle shape anisotropy.
View Article and Find Full Text PDFEur Phys J E Soft Matter
March 2016
A light-induced Soret effect accompanied by photoinduced adsorption of pigment nanoparticles is described in organic solvents. We report an unexpected inversion of the nanoparticle flux which is directed along the temperarture gradient at short exposures to the light and switches against the gradient at longer exposures. This change of flux direction is due to light-induced adsorption of the nanocrystals onto the substrates of the cell.
View Article and Find Full Text PDFAll breast cancer patients presenting preoperatively at the Dr. W.W.
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