Tim Tjardts

ZIF-8 provides accessible channel to small molecules like hydrogen to pass through the pores to interact at the CuO:Al surface. The interaction strength of VOCs with ZIF-8 is defined by the electronic polarizability of tested VOCs.

3D hydrogels are the state-of-the-art cell scaffold materials for ex vivo cultivation and tissue engineering. Different cell and tissue types have natural environments of different mechanics, chemistries or porosities, which cannot all be satisfied by standard hydrogels. In traditional hydrogel manufacturing these properties are dependent on another. In this study new scaffold materials named Aerohydrogels of ultra-low density are created by initiated chemical vapor deposition on sacrificial tetrapodal ZnO scaffolds. This novel fabrication process enabled the independent tuning of mechanics, porosity, surface chemistry and electrical conductivity. While the stiffness can be tuned based on the crosslinking, the surface chemistry can be chosen based on selected precursors and the porosity based on the sacrificial scaffold. Aerohydrogels with lower crosslinking resulted in a lower stiffness and better applicability towards muscle cells. In multilayer Aerohydrogels electrical conductivity was incorporated into the scaffold leading to an improved cell environment. Furthermore, the ultra-low density of the scaffold allowed the stimulated beating of the scaffolds containing C2C12 cells as well as the self-contraction of iPSC-derived cardiomyocytes. With Aerohydrogels next-generation tailored cell scaffolds for any cell-type are possible, addressing emerging challenges in drug testing, tissue engineering, bioelectronics and soft robotics.

Detection and degradation monitoring of micro- and nano-sized PVC via PIERS on Ag NF-TiO ₂ platform under continuous UV irradiation.

This study investigates the potential of Selective Laser Melting (SLM) to tailor the surface characteristics of Ti6Al4V directly during fabrication, eliminating the need for post-processing treatments potentially for dental implants. By adjusting the Volumetric Energy Density (VED) through controlled variations in the laser scanning speed, we achieved customized surface textures at both the micro- and nanoscale levels. SLM samples fabricated at moderate VED levels (50–100 W·mm³/s) exhibited optimized dual-scale surface roughness—a macro-roughness of up to 25.5–27.6 µm and micro-roughness of as low as 58.8–64.2 nm—resulting in significantly enhanced hydrophilicity, with water contact angles (WCAs) decreasing to ~62°, compared to ~80° on a standard grade 5 machined Ti6Al4V plate. The XPS analysis revealed that the surface oxygen content remains relatively stable at low VED values, with no significant increase. The surface topography plays a significant role in influencing the WCA, particularly when the VED values are low (below 200 W·mm³/s) during SLM, indicating the dominant effect of surface morphology over chemistry in these conditions. Biological assays using osteoblast-like MG-63 cells demonstrated that these as-built SLM surfaces supported a 1.5-fold-higher proliferation and improved cytoskeletal organization relative to the control, confirming the enhanced early cellular responses. These results highlight the capability of SLM to engineer bioactive implant surfaces through process-controlled morphology and chemistry, presenting a promising strategy for the next generation of dental implants suitable for immediate placement and osseointegration.

A setup consisting of two atmospheric plasma sources is used for the combined synthesis and passivation of nanoparticles. The silicon nanoparticles synthesized in the first source are analyzed for their chemical composition, morphology, and photoluminescence. The particles are then treated with a second plasma to induce surface passivation. The passivation process of the particles is monitored in real time using in situ infrared absorption spectroscopy. The results indicate that this treatment induces methylation of the silicon nanocrystals, which is further supported by XPS analysis. This surface passivation shifts the maximum of the photoluminescent signal to blue in the visible spectral region. Further optimization of the reported nanoparticle passivation process can provide a flexible tool for tuning nanoparticle properties.

Mixed metal oxide (MMO) nanoparticles (NPs) are hybrids consisting of two or more nanoscale metal oxides. Advantages of MMO NPs over single metal oxides include improved catalytic activity, enhanced electrical and magnetic properties, and increased thermal stability due to the synergy of the different oxide components. This study presents a novel fabrication route for TiO₂‐CeO₂ NPs enriched with oxygen vacancies using a Haberland‐type gas aggregation cluster source. The NPs, deposited from different segmented Ti/Ce targets under varying O₂ addition, were examined with respect to final composition, morphology, and Ti, Ce surface oxidation states. Particle formation mechanisms are proposed for the observed morphologies. Additionally, available O₂ during deposition and its impact on the formation of defective sites were investigated. Defective sites in TiO₂‐CeO₂ NPs were analyzed using transfer to X‐ray photoelectron spectroscopy and transmission electron microscopy without contact to ambient oxygen. The incorporation of Ce to the target exhibits synergistic effects on the synthesis process. Segmented Ti/Ce targets enable the deposition of a broad range of mixed oxide NPs with diverse compositions and morphologies at considerably enhanced deposition rates, which is vital for practical applications. The presented fabrication approach is expected to be applicable for a broad variety of MMO NPs.