145609-79-6Relevant articles and documents
Low Temperature Thermochromic Polydiacetylenes: Design, Colorimetric Properties, and Nanofiber Formation
Park, In Sung,Park, Hye Jin,Jeong, Woomin,Nam, Jihye,Kang, Youngjong,Shin, Kayeong,Chung, Hoeil,Kim, Jong-Man
, p. 1270 - 1278 (2016/03/25)
Owing to their stimulus responsive color changing properties, polydiacetylenes (PDAs) have been extensively investigated as colorimetric sensors. Thermochromic properties of PDAs have been the central focus of a number of investigations that were aimed not only at gaining a fundamental understanding of the physical basis of the color change but also at developing practical applications as temperature sensors. The thermochromic transition temperature of a PDA polymer is closely related to the melting point of the corresponding diacetylene (DA) monomer. In addition, the majority of PDAs described to date undergo a blue-to-red color change above room temperature because PDAs are generally derived from DA monomers that have melting points above room temperature. In the current study, we developed a series of low temperature colorimetric PDAs that were designed based on the reasoning that removal of the sources for strong headgroup interactions would lower the melting points of the corresponding DA monomers. This strategy was used to design and fabrication of PDA sensors that display color transitions in the range of 5-30°C. Moreover, the thermochromic transition temperatures of the PDAs were found to decrease by ca. 10°C when the alkyl chain length in the DA monomer is truncated by two methylene units. The results of FTIR and Raman spectroscopic analyses suggest that the PDA alkyl chain adopts an all-trans conformation in the blue-phase and some gauche forms exist in the alkyl chain in the red-phase PDA. Finally, the new PDAs are stable up to 300°C, and their processable nature enables them to be fabricated in nanofiber forms by employing an anodized aluminum oxide (AAO) membrane as a template.
Improvements in or relating to contrast agents
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, (2008/06/13)
Ultrasound contrast agents having microbubbles of gas or a gas precursor encapsulated by non-proteinaceous crosslinked or polymerised amphiphilic moieties, e.g. in the form of micelles, exhibit good stability in vivo upon administration and may if desired
Contrast agents
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, (2008/06/13)
The invention relates to diagnostic ultrasound contrast agents comprising vesicles comprising an amphiphilic phospholipid material capable of formation of gas-containing vesicles wherein the vesicles contain gas which comprises sulphur hexafluoride. The contrast agents and vesicles exhibit good stability in vivo upon administration and may if desired incorporate biodegradable linkages so as to possess particularly desired levels of biodegradability.