The combination of a polydopamine interface, solvothermal seeding of Pd(OAc)2, and ALD Al2O3 overcoat enables the formation of evenly-coated, ultralow Pd loading Ni foam monolith materials.

The major factor influencing the behavior of microbes growing in liquids in space is microgravity. We recently measured the transcriptomic response of the Gram-positive bacterium Bacillus subtilis to the microgravity environment inside the International Space Station (ISS) in spaceflight hardware called Biological Research in Canisters-Petri Dish Fixation Units (BRIC-PDFUs). In two separate experiments in the ISS, dubbed BRIC-21 and BRIC-23, we grew multiple replicates of the same B. subtilis strain in the same hardware, growth medium, and temperature with matching ground control samples (npj Micrograv. 5:1.2019, doi: 10.1038/s41526-018-0061-0). In both experiments we observed similar responses of the transcriptome to spaceflight. However, we also noted that the liquid cultures assumed a different configuration in microgravity (a toroidal shape) compared with the ground control samples (a flat disc shape), leading us to question whether the transcriptome differences we observed were a direct result of microgravity, or a secondary result of the different liquid geometries of the samples affecting, for example, oxygen availability. To mitigate the influence of microgravity on liquid geometry in BRIC canisters, we have designed an insert to replace the standard 60-mm Petri dish in BRIC-PDFU or BRIC-LED sample compartments. In this design, liquid cultures are expected to assume a more disk-like configuration regardless of gravity or its absence. We have: (i) constructed a prototype device by 3D printing; (ii) evaluated different starting materials, treatments, and coatings for their wettability (i.e., hydrophilicity) using contact angle measurements; (iii) confirmed that the device performs as designed by drop-tower testing and; (iv) performed material biocompatibility studies using liquid cultures of Bacillus subtilis and Staphylococcus aureus bacteria. Future microgravity testing of the device in the ISS is planned.

The synthesis, characterization, and thermogravimetric analysis of tris(N,N′-di-isopropylacetamidinate)molybdenum(III), Mo-(iPr-AMD) 3 , are reported. Mo(iPr-AMD) 3 is a rare example of a homoleptic mononuclear complex of molybdenum(III) and fills a longstanding gap in the literature of transition metal(III) trisamidinate complexes. Thermogravimetric analysis (TGA) reveals excellent volatilization at elevated temperatures, pointing to potential applications as a vapor phase precursor for higher temperature atomic layer deposition (ALD), or chemical vapor deposition (CVD) growth of Mo-based materials. The measured TGA temperature window was 200−314 °C for samples in the 3−20 mg range. To validate the utility of Mo(iPr-AMD) 3 , we demonstrate aerosol-assisted CVD growth of MoO 3 from benzonitrile solutions of Mo(iPr-AMD) 3 at 500 °C using compressed air as the carrier gas. The resulting films are characterized by X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy. We further demonstrate the potential for ALD growth at 200 °C with a Mo(iPr-AMD) 3 /Ar purge/300 W O 2 plasma/Ar purge sequence, yielding ultrathin films which retain a nitride/oxynitride component. Our results highlight the broad scope utility and potential of Mo(iPr-AMD) 3 as a stable, high-temperature precursor for both CVD and ALD processes.

Chemical vapor deposition (CVD), is an attractive method for the growth of two-dimensional (2D) materials such as transition metal dichalcogenides (TMDCs). However, it is an inherently wasteful process; the majority of chemical precursors end up in the waste stream and their corrosive nature deteriorates reactor components. While exploring the thermal CVD growth of ZrS 2 , the resulting corrosion build up on the downstream stainless-steel (SS) reactor components was collected and studied. Characterization of this material confirmed the presence of nanoplates composed of evenly distributed elements that constitute SS along with Cl, S, and trace Zr from the precursors. The material proved remarkably active as a photo-Fenton type catalyst for the aqueous degradation of methylene blue. Harvesting and upcycling this overlooked nanomaterial will reduce waste and concomitantly add value and enhance the sustainability of the overall TMDC fabrication process.

5-Aminosalicylic acid (5-ASA) is a first-line defense drug used to treat mild cases of inflammatory bowel disease. When administered orally, the active pharmaceutical ingredient is released throughout the gastrointestinal tract relieving chronic inflammation. However, delayed and targeted released systems for 5-ASA to achieve optimal dose volumes in acidic environments remain a challenge. Here, we demonstrate the application of atomic layer deposition (ALD) as a technique to synthesize nanoscale coatings on 5-ASA to control its release in acidic media. ALD Al 2 O 3 (38.0 nm) and ZnO (24.7 nm) films were deposited on 1 g batch powders of 5-ASA in a rotatory thermal ALD system. Fourier transform infrared spectroscopy, scanning electron microscopy, and scanning/transmission electron microscopy establish the interfacial chemistry and conformal nature of ALD coating over the 5-ASA particles. While Al 2 O 3 forms a sharp interface with 5-ASA, ZnO appears to diffuse inside 5-ASA. The release of 5-ASA is studied in a pH 4 solution via UV−vis spectroscopy. Dynamic stirring, mimicking gut peristalsis, causes mechanical attrition of the Al 2 O 3 -coated particles, thereby releasing 5-ASA. However, under static conditions lasting 5000 s, the Al 2 O 3 -coated particles release only 17.5% 5-ASA compared to 100% release with the ZnO coating. Quartz crystal microbalance-based etch studies confirm the stability of Al 2 O 3 in pH 4 media, where the ZnO films etch 41× faster than Al 2 O 3 . Such results are significant in achieving a nanoscale coating-based drug delivery system for 5-ASA with controlled release in acidic environments.