- Effect of Varying Alkyl Chain Length on Thermal Decomposition Temperature of Zinc(II) Xanthates and its Impact on Curing of Epoxy Resin
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Linear and branched zinc(II) xanthates with varying alkyl chain length were synthesized and characterized by 1H NMR, 13C NMR, and IR spectroscopy, as well as elemental analysis. Zinc sulfide as the final decomposition product upon thermal annealing of zinc(II) xanthates was confirmed by XRD analysis. Cure time for epoxy resin composite at various temperatures was analyzed employing zinc(II) xanthates (5 % mass) as latent cure catalysts. XRD investigation of the cured epoxy resin including zinc(II) xanthates upon thermal annealing revealed the presence of ZnS in-situ in the composite matrix, indicating the in-situ thermal decomposition of zinc(II) xanthates as probable mechanism for curing. Thermogravimetric analysis was performed to investigate the thermal decomposition temperature trend of zinc(II) xanthates. A parallel trend was observed correlating the thermal decomposition temperature trend of zinc(II) xanthates and the order of curing catalytic efficiency utilizing zinc(II) xanthates. In the case of linear alkylzinc(II) xanthates with an increase in the alkyl chain length, both thermal decomposition temperature and the cure time were enhanced. In contrast, in case of branched alkyl chain zinc(II) xanthates with increasing alkyl chain length show decreasing thermal decomposition temperature as well as cure time.
- Vagvala, Tarun Chand,Pandey, Shyam Sudhir,Krishnamurthy, Suvratha,Hayase, Shuzi
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- Synthesis, X-ray Single-Crystal Structural Characterization, and Thermal Analysis of Bis(O-alkylxanthato)Cd(II) and Bis(O-alkylxanthato)Zn(II) Complexes Used as Precursors for Cadmium and Zinc Sulfide Thin Films
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This work investigates tuning of the molecular structure of a series of O-alkylxanthato zinc and cadmium precursor complexes to enhance production of ZnS and CdS materials. The structures of several bis(O-alkylxanthato) cadmium(II) complexes (8-13) and bis(O-alkyl xanthato)zinc(II) complexes (18 and 19) are reported based on single crystal X-ray diffraction data. CdS and ZnS films were produced by the spin-coating of these metal complexes followed by their thermal decomposition to the corresponding metal sulfides. Thin films of CdS were deposited by spin-coating the bis(O-alkylxanthato) cadmium(II) precursors (7-13) on glass substrates, followed by annealing at 300 °C for 60 min. Thin films of ZnS were deposited by spin-coating bis(O-alkylxanthato) zinc(II) (14-20), followed by annealing at 200 °C for 60 min. The molecular complexes and solid state materials are characterized using a range of techniques including single-crystal X-ray diffraction, pXRD, EDS and XPS, DSC and TGA, UV-vis and PL spectroscopies, and electron microscopy. These techniques provided information on the influence of alkyl chain length on the thermal conditions required to fabricate metal sulfide films as well as film properties such as film quality, and morphology. For example, the obtained crystallite size of metal sulfide films formed is correlated to the hydrocarbon chain length of xanthate ligands in the precursor. The behavior of the complexes under thermal stress was therefore studied in detail. DTA and TGA profiles explain the relationship between hydrocarbon chain length, decomposition temperatures, and the energies required for decomposition. A higher decomposition temperature for complexes with longer hydrocarbon chains is observed compared to complexes with shorter hydrocarbon chains. Band-gap energies calculated from the optical absorption spectra alongside steady state and time-resolved photoluminescence studies are reported for CdS films.
- Bakly, Ali A.K.,Collison, David,Ahumada-Lazo, Ruben,Binks, David J.,Smith, Matthew,Raftery, James,Whitehead, George F. S.,O'Brien, Paul,Lewis, David J.
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supporting information
p. 7573 - 7583
(2021/05/26)
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- Preparation method of xanthate
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The invention discloses a preparation method of xanthate. According to the preparation method, tetrahydrofuran is taken as the reaction medium, monohydric alcohol or dihydric alcohol and caustic alkali carry out reactions at a temperature of 0 to 30 DEG C, finally desolvation is performed to obtain high purity xanthate, and the yield is high. The obtained xanthate has the advantages of little odor, higher purity, and higher yield, and is especially suitable for being used to prepare high grade xanthate with a carbon chain having a carbon number of 6 or more, ethyl xanthate, and dixanthate.
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Paragraph 0049; 0050; 0057; 0058; 0065; 0066; 0071; 0073
(2016/10/07)
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- In situ synthesis of pbs nanocrystals in polymer thin films from lead(II) xanthate and dithiocarbamate complexes: Evidence for size and morphology control
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Lead sulfide has been grown from single molecular precursors within a polymer matrix to form networks of PbS nanocrystals. These materials are model systems for the processing of polymer-nanoparticle layers for flexible hybrid photovoltaic devices. Processing is achieved by spin coating a solution containing the precursor and polymer onto a substrate, followed by heating of the film to decompose the precursor. The effect of precursor chemistry has been explored using lead(II) dithiocarbamates, their 1,10-phen adducts, and lead(II) xanthates with different alkyl chain lengths (butyl, hexyl, and octyl). The xanthates were found to be more promising precursors giving control over nanocrystal size and shape on variation of the alkyl chain length. The lead(II) octyl xanthate complex causes anisotropic growth, forming PbS nanowires within the polymer matrix.
- Lewis, Edward A.,McNaughter, Paul D.,Yin, Zhongjie,Chen, Yiqiang,Brent, Jack R.,Saah, Selina A.,Raftery, James,Awudza, Johannes A. M.,Malik, M. Azad,Obrien, Paul,Haigh, Sarah J.
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p. 2127 - 2136
(2015/04/14)
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