Impressively Printing Patterns of Gold and Silver Nanoparticles.

The optical and chemical properties of gold and silver nanoparticles make them useful for many applications, including surface enhanced spectroscopy-based biosensors, photostable colorants, enhanced photovoltaics, and nanoscale optical elements. We report a simple technique to generate patterns of gold and silver nanoparticles with controlled shape and shape-dependent optical properties using metal stamps to impress them onto a glass substrate or flexible polymers. The pressure flattens the nanoparticles, converting initially spherical nanoparticles into discs with reduced height and increased diameter.

Two halide-containing cesium manganese vanadates: synthesis, characterization, and magnetic properties.

Two new halide-containing cesium manganese vanadates have been synthesized by a high-temperature (580 °C) hydrothermal synthetic method from aqueous brine solutions. One compound, CsMn(VO)Cl, (1) was prepared using a mixed cesium hydroxide/chloride mineralizer, and crystallizes in the polar noncentrosymmetric space group Cmm2, with a = 16.7820(8) Å, b = 8.

Highly Conductive and Transparent Reduced Graphene Oxide Nanoscale Films via Thermal Conversion of Polymer-Encapsulated Graphene Oxide Sheets.

Despite noteworthy progress in the fabrication of large-area graphene sheetlike nanomaterials, the vapor-based processing still requires sophisticated equipment and a multistage handling of the material. An alternative approach to manufacturing functional graphene-based films includes the employment of graphene oxide (GO) micrometer-scale sheets as precursors. However, search for a scalable manufacturing technique for the production of high-quality GO nanoscale films with high uniformity and high electrical conductivity is still continuing.

One-Pot Hydrothermal Synthesis of Tb(GeO)O(OH) and KTbGeO: Preparation of a Stable Terbium(4+) Complex.

Two terbium germanates have been synthesized via high-temperature and high-pressure hydrothermal synthesis with 20 M KOH as a mineralizer using TbO as a starting material. Tb(GeO)O(OH) crystallizes in trigonal space group R3̅, is built up of isolated GeO units, and contains a complex arrangement of terbium oxide polyhedra. KTbGeO is a terbium(4+) pyrogermanate that is isostructural with KZrGeO and displays a rare stable Tb oxidation state in the solid state.

Three Unique Barium Manganese Vanadates from High-Temperature Hydrothermal Brines.

Three new barium manganese vanadates, all containing hexagonal barium chloride layers interpenetrated by [VO] groups, were synthesized using a high-temperature (580 °C) hydrothermal method. Two of the compounds were prepared from a mixed BaCl/Ba(OH) mineralizer, and the third compound was prepared from BaCl mineralizer. An interesting structural similarity exists between two of the compounds, BaMn(VO)(OH)Cl and BaMn(VO)(VO)O(OH)Cl.

Tuning Localized Surface Plasmon Resonance Wavelengths of Silver Nanoparticles by Mechanical Deformation.

We describe a simple technique to alter the shape of silver nanoparticles (AgNPs) by rolling a glass tube over them to mechanically compress them. The resulting shape change in turn induces a red-shift in the localized surface plasmon resonance (LSPR) scattering spectrum and exposes new surface area. The flattened particles were characterized by optical and electron microscopy, single nanoparticle scattering spectroscopy, and surface enhanced Raman spectroscopy (SERS).

Computational and experimental characterizations of silver nanoparticle-apolipoprotein biocorona.

With the advancement of nanotoxicology and nanomedicine, it has been realized that nanoparticles (NPs) interact readily with biomolecular species and other chemical and organic matter to result in biocorona formation. The field of the environmental health and safety of nanotechnology, or NanoEHS, is currently lacking significant molecular-resolution data, and we set out to characterize biocorona formation through electron microscopy imaging and circular dichroism spectroscopy that inspired a novel approach for molecular dynamics (MD) simulations of protein-NP interactions. In our present study, we developed a novel GPU-optimized coarse-grained MD simulation methodology for the study of biocorona formation, a first in the field.

Probing hydrogen bond energies by mass spectrometry.

Mass spectrometry with desorption electrospray ionization (DESI) is demonstrated to be useful for probing the strength of hydrogen bonding, exemplified by various complexes of benzothiazoles and carboxylic acids in the solid state. Efficiencies for fragmentation of the complexes, quantified by collision-induced dissociation (CID) technology, correspond well with energies of the hydrogen bonds of O-H···N and N-H···O bridging each pair of benzothiazole and carboxylic acid. Linear correlations (with correlation factors of 0.