کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1443385 | 1509455 | 2009 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
A comparative investigation between poly(1-ethynylpyrene) and poly(1,6-(3-ethynylpyrenylene)): Influence of the structure on the thermal, optical, electrochemical properties and conductivity
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
بیومتریال
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
A comparative investigation between trans-poly(1-ethynylpyrene) (trans-PEP) obtained chemically and poly(1,6-(3-ethynylpyrenylene) (E-PEP) prepared electrochemically was carried out. Thermal and optical properties of the polymers were studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and absorption spectroscopy. Electrochemical properties were evaluated by cyclic voltamperometry, in a 0.1 M Et4NClO4/THF solution at 10 mV/s, using a Pt disc as working electrode and Ag/AgCl as reference electrode. On the other hand, the conductivity of both polymers was measured in pressed pellet. Trans-PEP (T10 = 369 °C) showed a higher thermal stability than its homologue E-PEP (T10 = 256 °C). DSC of the polymers showed that trans-PEP exhibits a softening point at 330 °C, whereas E-PEP does it at 117 °C. Absorption spectra of the polymers revealed that trans-PEP exhibits two absorption bands at λ = 336 nm and λ = 580 nm due to the pyrene moieties and the highly conjugated polyacetylene main chain, respectively. By contrast, E-PEP showed only an absorption band at λ = 358 nm followed by a tail, which reveals that this polymer possesses a lower degree of conjugation. Molecular modelling performed in short segments of these polymers confirmed this hypothesis. Regarding the electrochemical properties, trans-PEP showed an anodic peak at 1500 mV and a conductivity value Ï = 2.7 Ã 10â2 S/cm, whereas E-PEP exhibited an anodic oxidation peak at 1670 mV and Ï = 8.4 Ã 10â2 S/cm.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Synthetic Metals - Volume 159, Issues 7â8, April 2009, Pages 659-665
Journal: Synthetic Metals - Volume 159, Issues 7â8, April 2009, Pages 659-665
نویسندگان
Juan Manuel Reyna-González, Martha Aguilar-MartÃnez, Alberto GarcÃa-Concha, Celso Palomar, Ernesto Rivera,