Localized Liquid Secretion from a Photopatterned Liquid-Crystal Polymer Skin
Liquid-releasing artificial skins are made from films made of a smectic liquid-crystal polymer network (LCN) photopolymerized in the presence of a photoactive azobenzene chromophore and a liquid-crystal porogen. The nonreactive porogen phase separates during the polymerization process, and the polymer forms a spongy polymer network filled with liquid. The liquid is excreted from the film when exposed to UV light upon conversion of trans-azobenzene to its cis isomer. Here, localized liquid secretion at preset positions at the polymer film is described. The design principle is based on creating a hybrid molecular architecture with both smectic and nonordered isotropic alignments in a continuo…
Dispersion of magnetic susceptibility in a suspension of flexible ferromagnetic rods
Abstract The properties of suspensions of magnetosomes extracted from magnetotactic bacteria are investigated. By using dynamic light scattering and measuring the dispersion of magnetic susceptibility it is shown that sonicated samples with broken magnetosome chains have qualitatively different behavior in comparison with native samples. This is explained by the presence of flexible chains of magnetosomes in non-sonicated samples which have the qualitative features of magnetic susceptibility predicted by the model of flexible magnetic rods.