13C/1H/2H ss-NMR on deuterated samples provide strong experimental evidence for the most probable monomer connectivity, π–π stacking, and the water dynamics in polydopamine.

Magnetite nanoparticles are of great importance in nanotechnology and nanomedicine and have found manifold applications. Here, the effect of coating of magnetite nanoparticles with organic stabilizers, such as O-phosphoryl ethanolamine, glycerol phosphate, phospho-l-ascorbic acid, phospho-d,l-serine, glycolic acid, lactic acid, d,l-malic acid, and d,l-mandelic acid was studied. Remarkably, this procedure led to an improvement of saturation magnetization in three cases rather than to an unfavorable decrease as usually observed. Detailed X-ray powder diffraction investigations revealed that changes in the average crystallite occurred in the coating process. Surprisingly, changes of the average crystallite sizes in either direction were further observed, when the exposure time to the stabilizer was increased. These results imply a new mechanism for the well-known coating of magnetite nanoparticles with stabilizers. Instead of the hitherto accepted simple anchoring of the stabilizers to the magnetite nanoparticle surfaces, a more complex recrystallization mechanism is likely, wherein partial re-dispersion of magnetite moieties from the nanoparticles and re-deposition are involved. The results can help producers and users of magnetite nanoparticles to obtain optimal results in the production of core shell magnetite nanoparticles.

No abstract

A low‐viscosity, solvent‐free process for the fabrication of thin silicone films for dielectric elastomer actuators is presented. Octamethylcyclotetrasiloxane and specially designed co‐monomers that function as cross‐linkers are pre‐polymerized to a liquid of low viscosity. This liquid is used to prepare thin films, which are then fully polymerized to a highly transparent, cross‐linked elastomer. The mechanical and electromechanical properties of the films are easily tuned by altering the amount of cross‐linker co‐monomer used.

The H-bonding driven supramolecular architectures, catemers or cyclic hexamers, of some tripodand triols were investigated using single crystal X-ray diffraction. The influence of the polar groups in the construction of the lattice of tripodands with 1,3,5-tris(1,3-dioxan-2-yl)benzene cores was pointed out by comparing the crystal structures of the derivatives with hydroxyl or methyl groups at the ends of the pendant arms.