Hierarchical ZnO microarchitectures assembled by ultrathin nanosheets: hydrothermal synthesis and enhanced photocatalytic activity. A simple and economical route to fabricate three-dimensional hierarchical ZnO microarchitectures has been developed by a team of Chinese scientists. The ZnO is assembled into a flowerlike morphology by many interleaving nanosheets which have ultrathin thickness of about 5 nm. The ZnO ‘flowers’ have high surface-to-volume ratio and a large population of unconventional (0001) surface planes. The team behind the research claim that this type of hierarchical ZnO microarchitectures display a strong structure-induced enhancement of photocatalytic performance and show a significantly improved photocatalytic activity over other monomorphological ZnO, such as ZnO nanoparticles, nanorods, and nanosheets. (J. Mater. Chem., 2011, Advance Article DOI:10.1039/C0JM03390A)
Photo-induced molecular alignment of trisazobenzene derivatives. Small-molecular trisazobenzene derivatives with a latent liquid-crystalline phase undergo a molecular realignment when exposed to linearly polarized visible light. These structures are unusually stable compared to structures based on other small-molecular organic compounds say the team behind the research. This phenomenon combines relatively short holographic writing times with small molecules in the fabrication of stable volume gratings. (J. Mater. Chem., 2011, Advance Article DOI:10.1039/C0JM03477K)
Restructuring of exponentially growing polyelectrolyte multilayer films induced by salt concentration variations after film deposition. In this hot paper a team of scientists based in France investigate films that experience changes in osmotic pressure through ionic strength changes of the contacting solution. The applied stresses lead often to the formation of holes. The team say that two types of holes are found: spherical holes formed by a direct increase or decrease of the ionic strength and non-spherical holes resembling cracks which appear after an increase followed by a decrease sequence of the ionic strength. (J. Mater. Chem., 2011, Advance Article DOI:10.1039/C0JM03457F)
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