Publications by authors named "Brian van Devener"

This study presents in situ observations of studtite (UOO(HO)·2HO) crystal growth utilizing liquid phase transmission electron microscopy (LP-TEM). Studtite was precipitated from a uranyl nitrate hexahydrate solution using hydrogen peroxide formed by the radiolysis of water in the TEM electron beam. The hydrogen peroxide (HO) concentration, directly controlled by the electron beam current, was varied to create local environments of low and high concentrations to compare the impact of the supersaturation ratio on the nucleation and growth mechanisms of studtite particles.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the challenges of electronic tuning in heterogeneous catalysis when using organic ligands that strongly bind to catalyst surfaces, specifically focusing on gold nanoparticles under 2 nm in size.
  • Gold nanoparticles are synthesized using two types of ligands: triphenylphosphine (TPP), which donates electrons, and triphenylmethyl mercaptan (TPMT), which withdraws electrons, highlighting differences in catalytic activity.
  • Experiments show that TPP-bound nanoparticles are active for all tested reactions, while TPMT-bound ones lose activity for resazurin reduction, demonstrating how the choice of ligands can influence the catalytic behavior of gold nanoparticles.
View Article and Find Full Text PDF

While bound organic ligands provide steric protection against aggregation for metallic nanoparticles in solution, they can block a large fraction of the surface atoms which are needed for binding in catalysis and sensing applications. In this work, highly accessible Au nanoparticles ligated with bis(diphenylphosphine) molecules are synthesized and characterized in solution. Characterization is performed using high angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), ultraviolet-visible (UV-Vis) spectroscopy, and fluorescence chemisorption experiments.

View Article and Find Full Text PDF

Since silver ion is known for its antimicrobial function, most of the research has focused mainly on toxicity effects rather than the role of silver ion in general biology and the behind mechanism of actions of silver ion in mammalian cells. Moreover, a conventional in vitro approach to estimate the effects of silver ion on cells does not provide information about the biochemical changes and might accompany artifacts due to invasive and destructive sample preparation processes. In the present study, in-situ real time approaches were applied to evaluate the impact of silver ion (0.

View Article and Find Full Text PDF

The concentration of extracellular vesicles (EVs) is an essential attribute of biofluids and EV preparations. EV concentration in body fluids was correlated with health status. The abundance of EV secreted by cultured cells into growth medium is vital in signaling studies, tissue and disease models, and biomanufacturing of acellular therapeutic secretome.

View Article and Find Full Text PDF

Various polymers used in controlled release applications exhibit solution-based thermal responses. Unfortunately, very few characterization and imaging techniques permit resolution of individual polymers during their thermally-triggered phase transitions. Here, we demonstrate the use of temperature-ramp liquid-cell transmission electron microscopy (LCTEM) for real-time evaluation of the solution and interfacial behavior of elastinlike polypeptides (ELPs) and their self-assembled nanostructures over a temperature range incorporating their intrinsic lower critical solution temperatures (LCSTs).

View Article and Find Full Text PDF

The effects of collision energy (Ecol) and five different modes of H2CO+ vibration on the title reaction have been studied over the center-of-mass Ecol range from 0.1 to 3.2 eV, including measurements of product ion recoil velocity distributions.

View Article and Find Full Text PDF

The effects of collision energy (E(col)) and six different H(2)CO(+) vibrational states on the title reaction have been studied over the center-of-mass E(col) range from 0.1 to 2.6 eV, including measurements of product ion recoil velocity distributions.

View Article and Find Full Text PDF

We report the effects of collision energy (Ecol) and five different H2CO+ vibrational modes on the reaction of H2CO+ with C2D4 over the center-of-mass E(col) range from 0.1 to 2.1 eV.

View Article and Find Full Text PDF