Porous hydrogel scaffolds are ideal candidates for mimicking cellular microenvironments, regarding both structural and mechanical aspects. We present a novel strategy to use uniquely designed ceramic networks as templates for generating hydrogels with a network of interconnected pores in the form of microchannels. The advantages of this new approach are the high and guaranteed interconnectivity of the microchannels, as well as the possibility to produce channels with diameters smaller than 7 μm. Neither of these assets can be ensured with other established techniques. Experiments using the polyacrylamide substrates produced with our approach have shown that the migration of human pathogenic Acanthamoeba castellanii trophozoites is manipulated by the microchannel structure in the hydrogels. The parasites can even be captured inside the microchannel network and removed from their incubation medium by the porous polyacrylamide, indicating the huge potential of our new technique for medical, pharmaceutical, and tissue engineering applications.

A [2]rotaxane shuttle for (light‐driven) proton transport has been designed and synthesized. The rotaxane contains a macrocyclic ring that carries a pyridine nitrogen atom as a basic center to bind and to transport a proton. The axis includes an amide binding site for the macrocycle and a positive charge in close vicinity. Upon protonation of the pyridine nitrogen atom, the hydrogen bond is broken and Coulomb repulsion between the protonated pyridine and the permanent positive charge in the axis pushes the protonated macrocycle to the other end of the axis. By variation of the pH the ring can shuttle to and fro. Its locations on the axis were determined by NMR spectroscopy.

A 0‐3 nanocomposite of CdSe (crystalline nanoparticles) and Cr2Se3 (amorphous matrix) was synthesized via a soft chemical approach and characterized by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). Particularly the transformation of the 0‐3 composite is explored in situ under electron beam irradiation and thermal annealing inside the TEM. In situ electron beam irradiation removed exclusively the CdSe nanoparticles and generated a porous Cr2Se3 matrix with a slightly increased crystallinity. The highly localized beam heating and knock‐on effect are attributed to the origin of the in situ irradiation transformation. During the in situ thermal annealing process of the 0‐3 nanocomposite CdSe particles are eliminated and crystalline nano‐ and microparticles of Cr2Se3 are generated. Also the formation of chromium enriched crystallites is observed. All of these in situ results are compared with conventional ex situ methods and discussed in terms of the different mechanisms associated with electron beam interaction and size effects of the nanocomposite.

The noncovalent binding of spiropyran to candle-soot-covered surfaces is investigated for wettability switching using a coating procedure realized with a drop casting process of using 0.001 mol/L spiropyran in a 5 : 1 toluene-acetone mixture. Scanning electron microscopy images reveal a resulting surface with spiropyran flakes in the candle soot. A reversible switching with UV light and blue or green light is achieved, starting from an initial contact angle of 130 ∘ ± 9.68 ∘ . The highest contact angle difference is 41 ∘ and reversibility has been shown for several switching cycles. Hence, our methods provide an easy-to-use strategy to generate surfaces with switchable wettability.

The properties of rotaxanes and their constituents, ring and axle, sometimes do not differ much from one another resulting in tedious workup. In the case of a rotaxane designed to shuttle protons across a biological membrane (3-4 nm), molecular weight, shape, and functional groups of axle and rotaxane are similar. But when the macrocyclic ring of the rotaxane carries a fluorous residue, the fluorous effect distinguishes the rotaxane from the axle because the latter carries no fluorine atoms. This concept has been exploited to synthesize a [2]rotaxane in which the macrocyclic ring is protonable and the axle contains a permanent positive charge. Upon protonation/deprotonation of the macrocycle, a shuttling process is induced, which can lead to the transport of protons.