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The application of a new barbitoric acid based dye (5-[(3,5-dicarboxyphenyl)azo]-barbituric acid) for the fabrication of dye sensitized solar cell is demonstrated. Simply, a mixture of multi-walled carbon nanotubes and the dye, mixed under ultrasonication, is used as a photosensitive agent of photoanode. Carbon nanotubes addition to the photoanode activates the dye to function as the sensitive element of the cell. Electrochemical impedance spectroscopy was employed for the extraction of electrochemical parameters of the cells. According to the I/V curves the essential indexes of the solar cell including: current density at short circuit condition (Jsc), voltage at open circuit condition (Voc), fill factor (FF) and photon to current conversion efficiency (PCE) are improved in the presence of carbon nanotubes. Carbon nanotubes interaction with the dye not only improves the dye absorbance efficiency but also increases the absorbance wavelength range in the visible region. This is assigned to efficient interaction of carbon nanotubes with the dye adsorbed on TiO2. At the optimized condition, the essential indexes of Jsc, Voc, FF and PCE% of dye/carbon nanotubes-based solar cell are 3.5 ± 0.3 (mA cm−2), 0.65 ± 0.05 V, 0.77 ± 0.07 and 1.75 ± 0.1, respectively. [ABSTRACT FROM AUTHOR]

This paper reports experiments on grafting of a new polymerizable monomer onto organophilic montmorillonite. The monomer, 5-methacryloyloxy-1,4:36- D-anhydrosorbitol (MAS), was synthesized by reacting methacryloyl chloride and isosorbide in the presence of Et3N as base. Then, Cloisite 20A was reacted with vinyltrichlorosilane to replace the edge hydroxyl groups of the clay with a vinyl moiety. Because the reaction liberates HCl, it was performed in the presence of sodium hydrogen carbonate to prevent the exchange of quaternary alkylammonium cations with H+ ions. Only the silanol groups on the edge of the clay react with vinyltrichlorosilane. After the reaction, the product maintained the same basal spacing as the precursor. The radical polymerization of the product with MAS as a vinyl monomer led to chemical grafting of the polymer onto the montmorillonite surface. The homopolymer formed during polymerization was separated from the grafted organoclay by Soxhlet extraction. Chemical grafting of the polymer onto Cloisite 20A was confirmed using infrared spectroscopy. The prepared nanocomposite materials and the grafted nanoparticles were studied using X-ray diffraction and scanning and transmission electron microscopy. Exfoliated nanocomposite was obtained for 1 wt% clay loadings. The nanocomposites were studied using thermogravimetric and dynamic mechanical analyses. Improved thermal properties were observed for nanocomposites with 1-5 wt% clay content. © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]