Category Chemistry/Nanotechnology

1. (Schematic diagram of mushroom-shaped structure fabrication)
2. SEM image of mushroom-shaped structure
3. Image of superomniphobic property of different types of liquid

Scientists have developed a fabrication technology that can inexpensively produce surfaces capable of repelling liquids, including water and oil. The team used the photofluidization of azobenzene molecule-containing polymers to generate a superomniphobic surface which can be applied for developing stain-free fabrics, non-biofouling medical tubing, and corrosion-free surfaces. Mushroom-shaped surface textures, also called doubly re-entrant structures, are known to be the most effective surface structure that enhances resistance against liquid invasion, thereby exhibiting superior superomniphobic property.

However, the exist...

Electrotunable nanoplasmonic liquid mirror. Nature Materials, 2017; DOI: 10.1038/nmat4969

By finely tuning the distance between nanoparticles in a single layer, researchers have made a filter that can change between a mirror and a window. The development could help scientists create special materials whose optical properties can be changed in real time. These materials could then be used for applications from tuneable optical filters to miniature chemical sensors. Creating a ‘tuneable’ material has been a challenge because of the tiny scales involved. In order to tune the optical properties of a single layer of nanoparticles – which are only tens of nanometres in size each – the space between them needs to be set precisely and uniformly.

To form the layer, the team from Imperial College Lo...

Representative HAADF images and particle size distributions for the unsupported AuPd-PVP sol in the fresh (A to C) and after a CH4 oxidation reaction (D to F). CREDIT Graham J. Hutchings and Christopher J. Kiely

Liquid methanol is widely used as a feedstock for other chemicals and also has considerable potential as an alternative fuel source. However, converting methane—the primary component of abundant natural gas—into methanol is currently achieved by an indirect process which requires high heat and pressure. Now researchers have discovered a new approach that allows the direct conversion of methane to methanol utilizing molecular oxygen under much milder reaction conditions.

A team has used colloidal gold-palladium (Au-Pd) nanoparticles to directly oxidize methane to methanol with h...

Various configurations of oxygen adsorption with corresponding energies. (a) Sulphur, molybdenum, and oxygen are represented by yellow, blue, and red spheres, respectively. The sulphur vacancy site is represented by the cross. (b) Nudged elastic band calculation of the energy barrier for migration of an oxygen molecule towards a sulphur vacancy and respective trapping. The energy barrier, measured from the starting point, is 56 meV. The calculation was performed in the spin-averaged state. (c) Calculated ionization levels for relevant defects (all energies are in eV). VBM and CBM refer to the valence band maximum and conduction band minima, respectively. (d) Representation of the charge density of the trapped electrons at sulfur vacancies.

National University of Singapore (NUS) researchers...