Chem Commun (Camb)
December 2009
A novel design strategy that extends metal-organic frameworks (MOFs) into tractable metallo-polymers was successfully explored by incorporating a homologous series of alkyl side chains to an organic linker, in which drastic solid to solid transformation is also observed.
View Article and Find Full Text PDFDespite nearly three decades of materials development, the transport properties in the 'metallic state' of the so-called conducting polymers are still not typical of conventional metals. The hallmark of metallic resistivity--a monotonic decrease in resistivity with temperature--has not been obtained at temperatures over the full range below room temperature; and a frequency dependent conductivity, sigma(omega), typical of metals has also not been observed. In contrast, the low-temperature behaviour of 'metallic' polymers has, in all previous cases, exhibited an increase in resistivity as temperature is further decreased, as a result of disorder-induced localization of the charge carriers.
View Article and Find Full Text PDFWe demonstrate that the mesophase morphology of the layered photorefractive polymers has a substantial influence on the photorefractive properties, especially in reflection grating geometries with a minimal grating spacing. The layered morphology of the photoconductive polymers based on poly(p-phenyleneterephthalate) (PPT) with pendent carbazole (CZ) groups can be efficiently controlled by changing their molecular weight. Photorefractive composites based on PPT-CZ polymers with different chromophores, diethylaminodicyanostyrene (DDCST) or piperidinodicyanostyrene (PDCST), show anisotropic morphology induced by the squeezing flow during sample preparation.
View Article and Find Full Text PDFJ Colloid Interface Sci
August 2005
The electrorheological (ER) properties of poly(2-dodecyloxyaniline) (PDOA) suspensions in silicone oil were investigated. The ER behavior of such suspensions of polyaniline particles depends on the type of stabilizer and doping or dedoping level. Here we report on the ER behavior of particles of a substituted polyaniline with long alkyl pendants.
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