Purposefully Designed Surfactants for Facile and Controllable Gold Colloidal Nanocrystal Synthesis.

Three new cationic surfactants--cetyl-bis(2-dimethylaminoethyl)ether bromide (CBDEB), dodecyl-bis(2-dimethylaminoethyl)ether bromide (DBDEB), and -hexyl-bis(2-dimethylaminoethyl)ether bromide (HBDEB)-have been designed herein using a simple and tailorable synthesis route. CBDEB and DBDEB, the 16- and 12-carbon chain surfactants, demonstrate facile, rapid, and controllable aqueous syntheses of gold nanoparticles (AuNPs) as dual-action reducing and capping agents. The synthesis strategy, using only surfactant and HAuCl salt, and 4 min of heating at 80 °C, results in spherical AuNPs (average diameters of 13.

Laser-induced sound pinging for the rapid determination of total sugar or sweetener content in commercial beverages.

We recently reported on fixed-path length laser-induced sound pinging (FPL-LISP) as a rapid photoacoustic technique employing an inexpensive benchtop tattoo-removal laser for reliably determining the speed of sound in low-volume fluids. In this contribution, we demonstrate the capacity of FPL-LISP to analyze representative commercial beverages for their natural or artificial sweetener contents. As a benchmark, the speed of sound was determined for solutions of sugars (glucose, fructose, sucrose), mock high fructose corn syrup (HFCS-55), and 12 household sweeteners (culinary sugars, syrups, honey, molasses) across the concentration range of 1-20% w/v in water, simulating the typical sweetener range found in commercial soft drinks.

Combined Small-Angle Neutron Scattering, Diffusion NMR, and Molecular Dynamics Study of a Eutectogel: Illuminating the Dynamical Behavior of Glyceline Confined in Bacterial Cellulose Gels.

A deep eutectic solvent (DES) entrapped in a bacterial cellulose (BC) network gives rise to a gelatin-like, self-supported material termed a bacterial cellulose eutectogel (BCEG). Although this novel material holds potential for numerous industrial, environmental, energy, or medical applications, little is known about the structural features or dynamical behavior within a eutectogel. In this work, we employ X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and small-angle neutron scattering (SANS) to probe the structural and diffusive behavior of the prevailing DES glyceline (1:2 molar ratio of choline chloride:glycerol) confined within bacterial cellulose.

On the non-innocence of the imidazolium cation in a rapid microwave synthesis of oleylamine-capped gold nanoparticles in an ionic liquid.

We report a very fast (10-30 s) microwave method to prepare oleylamine-capped, monodisperse ca. 8-11 nm gold nanoparticles in an ionic liquid. A pyrrolidinium-based ionic liquid proved an excellent medium for the task whereas, despite their popularity in nanosynthesis, imidazolium ionic liquids gave no colloidally-stable gold nanoparticles in an otherwise identical reaction.

Ionic Liquid Anion Controlled Nanoscale Gold Morphology Grown at a Liquid Interface.

Two different ionic liquids comprising the tetrabutylphosphonium cation ([P]) paired with the strongly coordinating anions 6-aminocaproate ([6-AC]) or taurinate ([tau]) were prepared and employed in an aqueous/organic liquid bilayer system to generate nanoscale gold by Au(OH) photoreduction. Generally, as the concentration of ionic liquid in the organic phase was increased, the resulting quasi-spherical gold nanoparticles were smaller in size and presented less aggregation, leading to marked increases in the catalytic efficiency for 4-nitrophenol reduction using borohydride. The diffusion of the ionic liquids across the liquid/liquid interface was also investigated, revealing partition coefficients of 6.

Ionic Liquids Can Permanently Modify Porous Silicon Surface Chemistry.

To develop ionic liquid/porous silicon (IL/pSi) microarrays we have contact pin-printed 20 hydrophobic and hydrophilic ionic liquids onto as-prepared, hydrogen-passivated porous silicon (ap-pSi) and then determined the individual IL spot size, shape and associated pSi surface chemistry. The results reveal that the hydrophobic ionic liquids oxidize the ap-pSi slightly. In contrast, the hydrophilic ionic liquids lead to heavily oxidized pSi (i.