Light-induced contraction and extension of single macromolecules on a modified graphite surface.

Synthetic rigid-rod polymers incorporating multiple azobenzene photoswitches in the backbone were deposited from solution onto a monolayer of octadecylamine covering the basal plane of graphite. Large contractions and extensions of the single macromolecules on the surface were induced by irradiation with UV and visible light, respectively, as visualized by scanning force microscopy. Upon contraction, the single polymer chains form more compact nanostructures and also may move across the surface, resembling a crawling movement.

Microwave-induced nanoscale zero-valent iron degradation of perchloroethylene and pentachlorophenol.

Unlabelled: Microwave (MW) is applied to enhance perchloroethylene (PCE) or pentachlorophenol (PCP) removal using zero-valent iron (ZVI; Fe(0)) as the dielectric medium. ZVI has a much higher dielectric loss factor (39.5) than other media; it is capable of absorbing MW radiation rapidly to speed up the release of electrons, leading to rises of the ZVI particle surface temperature.

Enhanced degradation of chlorobenzene in aqueous solution using microwave-induced zero-valent iron and copper particles.

Microwaves were applied to reduce the activation energy of chlorobenzene in aqueous solution and enhance its removal using nanoscale zero-valent iron (Fe0) or zero-valent copper (Cu0) particles as dielectric media. When Fe0 and Cu0 particles absorb microwave energy, the electrical potential difference causes the metal electrons to rotate faster, thus producing more heat. The microwave-irradiated metal particles reduced the chlorobenzene activation energy by 6.