- Design and synthesis of polydiacetylenes, and their low temperature irreversible thermochromic properties
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A thermochromic material that show irreversible color change at or below freezing temperatures has potential utility as a temperature indicator for frozen food and meat products, therefore, the goods transporters and customers would easily recognize when the goods exposed to high temperatures during their storage and delivery. In this study, we have successfully synthesized and used polydiacetylenes functionalized with glycol ester groups as a thermochromic dye, which show irreversible thermochromic behavior at below freezing temperatures. The photochromic and thermochromic properties of diacetylenes were investigated in the solid state, and color-transition temperatures for poly(DCDA-EGME), poly(DCDA-DGME) and poly(DCDA-TGME) were found to be 2, ?10 and ?16 °C, respectively. Moreover, we prepared a paper test strip and used as a warning indicator for deep freeze products.
- Mergu, Naveen,Son, Young-A.
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- Polydiacetylene paper-based colorimetric sensor array for vapor phase detection and identification of volatile organic compounds
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Detection and identification of VOCs in their vapor phase is essential for safety and quality assessment. In this work, a novel platform of a paper-based polydiacetylene (PDA) colorimetric sensor array is prepared from eight diacetylene monomers, six of which are amphiphilic and the other two are bolaamphiphilic. To fabricate the sensors, monomers are coated onto a filter paper surface using the drop-casting technique and converted to PDAs by UV irradiation. The PDA sensors show solvent induced irreversible color transition upon exposure to VOC vapors. When combined into a sensing array, the color change pattern as measured by RGB values and statistically analyzed by principal component analysis (PCA) is capable of distinguishing 18 distinct VOCs in the vapor phase. The PCA score and loading plots also allow the reduction of the sensing elements in the array from eight to three PDAs that are capable of classifying 18 VOCs. Utilizing an array containing only two PDAs, various types of automotive fuels including gasoline, gasohol and diesel are successfully classified. The Royal Society of Chemistry 2012.
- Eaidkong, Thichamporn,Mungkarndee, Radeemada,Phollookin, Chaiwat,Tumcharern, Gamonwarn,Sukwattanasinitt, Mongkol,Wacharasindhu, Sumrit
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experimental part
p. 5970 - 5977
(2012/06/18)
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- POLYFLUORINE-SUBSTITUTED ALKYNES AND ALKADIYNOIC ACIDS II. SYNTHESIS OF ω-HYDROPOLYFLUOROALKYNES AND ALKADIYNOIC ACIDS BASED ON THEM
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The reaction of propargylaluminum sesquibromide with 7-monohydroperfluoroheptanal and methyl 7-monohydroperfluoroheptanoate in THF results in the formation of 1,3,3,4,10-pentahydroperfluoro-1-decyn-4-ol and 4-propargyl-1,3,3,4,10-pentahydroperfluoro-1-decyn-4-ol. 3-(Trihydroperfluoroalkoxy)-1-propynes were obtained from the alcohol-telomers and propargyl chloride.The corresponding mercury compounds, triazoles, diacetylenic alcohols, and carboxylic and hydroxamic acids were synthesized from the two types of alkynes.The acids are inhibitors of 5- and 15-lipoxygenases.
- Radchenko, O. A.,Proshakova, E. V.,Kotlinskaya, A. N.,Il'chenko, A. Ya.
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p. 1281 - 1290
(2007/10/02)
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- Diacetylenic Liquid Crystalline Diesters
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Diesters of 10,12-docosadiyne-1,22-dionic acid with 4-hydroxy-4'methoxybiphenyl (I), 4-hydroxy-4'-methoxyazoxybenzene (II), and 4-hydroxy-4'-methoxy(2,2'-dimethyl) azoxybenzene have been prepared.The diester I displayed high sensitivity to light and u.v. irradiation while it was not mesomorphic.In contrants, diesters II and III were nematic while displaying considerably less radiation sensitivity.A suggested reason for this difference in behavior is the difference in the molecular packing of the corresponding crystal.The differnce in the mesomorphic behavior between II and III is explained in terms of mesogen broadening and distortion of the mesogen molecule of III by the methyl substituents.Keywords: diacethylenic diesters, synthesis of, liquid crystalline order
- Ozcayir, Y.,Blumstein, A.
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p. 237 - 246
(2007/10/02)
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- Diacetylenic Liquid Crystalline Polymers II: Derivatives of 10,12-Docosadiyne-1,22-Dioic Acid
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Polymers of 10,12-docosadiyne-1,22-dioic acid with different mesogenic groups have been prepared.The mesogenic groups were diphenyl (Polymer I); p-diphenylazoxy (Polymer II); 2,2'-dimethyldiphenylazoxy (Polymer III); 2-methyldiphenylazomethine (Polymer IV) and α-methylstilbene (Polymer V).All polymers crystallized extensively at room temperature, but only polymers I and V displayed an enantiotropic smectic mesophase.The X-ray diffractograms were consistent with a smectic H mesophase for both polymers.Polymers I and V differed also from polymers II-IV by enhanced reactivity of the diacetylenic moiety.A model for chain packing consistent with the X-ray diffraction pattern of the crystalline and the smectic phase is proposed.Keywords: diacetylenic polyesters, synthesis of, liquid crystalline order
- Ozcayir, Y.,Asrar, J.,Clough, S. B.,Blumstein, A.
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p. 167 - 178
(2007/10/02)
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