Sharif Digital Repository

Three new chromophores based on the triphenylamine (MM, DM, DN) with various novel electron withdrawing anchoring groups have been synthesized for use in dye-sensitized solar cells (DSSCs). The sensitizers were characterized by 1H and 13C NMR, Mass, UV–Vis, and electrochemical analysis. The HOMO and LUMO electron distributions of the sensitizers were calculated using density functional theory on a B3LYP level for geometry optimization. The DSSC device based on DM dye showed the best photovoltaic performance among MM and DN dyes: maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 98 %, short circuit current (JSC) of 4.58 mA/cm2, open circuit voltage (VOC) of... 

The effect of electrostatic field on the aggregation rate and aggregate size of asphaltene particles precipitated from three different crude oil samples suspended in a mixture of toluene and n-heptane (a model oil) was investigated. An electrode-embedded glass micro-model utilizing a high-voltage direct current power supply was utilized in this study. The asphaltene particle size and the rate of aggregation under the electric field were monitored using a high-resolution optical microscope and the average aggregate size for asphaltene particles was estimated using image processing software. To investigate the effects of structural parameters on asphaltene aggregation rate, aggregate size and... 

Here, we report the synthesis and characterization of a binuclear Co(ii) complex (Co2(2py)2Cl4) with two dinaphtho-diazacrown ether macrocyclic ligands, bearing two pyridine arms as a colourimetric and fluorescent sensor for detecting different xylene isomers as well as acting as a catalyst for the oxidation of o- and m-xylene under vacuum at room temperature. Chromogenic detection occurred when Co2(2py)2Cl4 was exposed to the xylene isomers, wherein the original blue colour of the complex changed to green and green-blue in the presence of o- and m-xylene, respectively. Meanwhile, no colour change was observed in the presence of the p-xylene isomer. Fluorescence spectroscopy revealed that... 

A novel glucose biosensor based on chromophore (silver nanoparticles) decolorizing for the photometric determination of glucose was developed. Silver nanoparticles are directly synthesized in the sol-gel matrix by a one-step method based on the reduction of the inorganic precursor AgNO3 and were used for the preparation, characterization and calibration of a highly sensitive and cost-effective localized surface plasmon resonance-based glucose biosensor. In the presence of glucose oxidase (GOx) and due to the enzyme-substrate (glucose) reaction, H2O2 was produced and silver nanoparticles in the sol-gel glass have the ability for the decomposition of hydrogen peroxide. Due to the degradation...