We present birefringence and fluorescence confocal microscopy studies of melamine particles in a liquid-crystalline host solvent. The liquid crystal has a cholesteric phase at room temperature with a helical pitch that can be modified by changing the composition. The pitch employed here is always less than the particle diameter (3 microm). We demonstrate via birefringence that the mesogens preferentially anchor flat at the melamine surface. Via studies in a sample cell with aligning surfaces we show that although the particles form chains in a nematic liquid crystal they organize in 2D plates in a cholesteric. Fluorescence confocal microscopy and particle location analysis are used to determine the radial distribution function and to evaluate the particle aggregation number as a function of pitch length. We discuss possible explanations for the self-organization.

We present a simple method for preparing large quantities of micrometer-sized core−shell silica rods, via needle-like akaganeíte (β-FeOOH) template particles. The preparation of the akaganeíte needles by aging ferric chloride solutions at elevated temperature is explored in order to find improved conditions for the formation of well-dispersed high-aspect-ratio needles. The influence of reaction conditions on irreversible bundling of the needles, yield, and the particle size distribution are reported and discussed. Subsequent coating of the template particles with silica leads to core−shell rods with an aspect ratio (A = L/D) that decreases with shell thickness. This facilitates control over the final aspect ratio and is accompanied by a decrease in the polydispersity. The composition of these core−shell particles offers various possibilities in terms of modifying the particle properties, which we demonstrate by preparing fluorescent particles and hollow silica rods while outlining other interesting options. We also include some optical microscopy images illustrating particle behavior and ordering under gravity, in a homogeneous magnetic field and at the interfaces of phase-separated binary liquids.

A SiC way to split water: Illuminated p‐type 4H‐SiC, as a photocathode short‐circuited to Pt, was found to split water (see picture). The hydrogen generated is stored to a considerable extent in the solid.

Bicontinuous interfacially jammed emulsion gels, in short 'bijels', rely on a trapped layer of colloidal particles for their stability. These structures have traditionally been created using spherical colloidal particles. Here we show for the first time the use of rod-shape particles to stabilize bijels. We show that domain size decreases more rapidly with particle concentration in the case of rods compared to spheres. Large-scale analysis and detailed examination of images show that the packing fraction of rods is much higher than expected, in part, due to the role of 'flippers'.

Ein p‐Halbleiter bestehend aus 4H‐SiC ist bei Lichteinstrahlung zur Wasserspaltung befähigt, wenn er als Photokathode mit einer Pt‐Anode kurzgeschlossen wird. Der erzeugte Wasserstoff wird zu einem beträchtlichen Teil im Festkörper gespeichert.