S.R. Majid

FTIR Studies of plasticized poly(vinyl alcohol)-chitosan blend doped With NH4NO3 polymer electrolyte membrane

Fourier transform infrared (FTIR) spectroscopy studies of poly(vinyl alcohol) (PVA), and chitosan polymer blend doped with ammonium nitrate (NH(4)NO(3)) salt and plasticized with ethylene carbonate (EC) have been performed with emphasis on the shift of the carboxamide, amine and hydroxyl bands. 1% acetic acid solution was used as the solvent. It is observed from the chitosan film spectrum that evidence of polymer-solvent interaction can be observed from the shifting of the carboxamide band at 1660 cm(-1) and the amine band at 1591 cm(-1) to 1650 and 1557 cm(-1) respectively and the shift of the hydroxyl band from 3377 to 3354 cm(-1). The hydroxyl band in the spectrum of PVA powder is observed at 3354 cm(-1) and is observed at 3343 cm(-1) in the spectrum of the PVA film. On addition of NH(4)NO(3) up to 30 wt.%, the carboxamide, amine and hydroxyl bands shifted from 1650, 1557 and 3354 cm(-1) to 1642, 1541 and 3348 cm(-1) indicating that the chitosan has complexed with the salt. In the PVA-NH(4)NO(3) spectrum, the hydroxyl band has shifted from 3343 to 3272 cm(-1) on addition of salt from 10 to 30 wt.%. EC acts as a plasticizing agent since there is no shift in the bands as observed in the spectrum of PVA-chitosan-EC films. The mechanism of ion migration is proposed for the plasticized and unplasticized PVA-chitosan-NH(4)NO(3) systems. In the spectrum of PVA-chitosan-NH(4)NO(3)-EC complex, the doublet CO stretching in EC is observed in the vicinity 1800 and 1700. This indicates that there is some interaction between the salt and EC.

TiO2/Chitosan-NH4I(+I2)-BMII-Based Dye-Sensitized Solar Cells with Anthocyanin Dyes Extracted from Black Rice and Red Cabbage

Dye sensitized solar cells (DSSCs) were fabricated using anthocyanin dye and polymer electrolyte with ammonium iodide (NH4I) salt. The study was designed to focus on increasing the efficiency of the DSSC. DSSC using 26.9 wt. % chitosan-22 wt. % NH4I(

Performance of Dye-Sensitized Solar Cells with (PVDF-HFP)-KI-EC-PC Electrolyte and Different Dye Materials

A plasticized polymer electrolyte system composed of PVDF-HFP, potassium iodide (KI), and equal weight of ethylene carbonate (EC) and propylene carbonate (PC) has been used in a dye-sensitized solar cell (DSSC). The electrolyte with the composition 40 wt. % PVDF-HFP-10 wt. % KI-50 wt. % (EC

Conductivity studies on chitosan/PEO blends with LiTFSI salt

Chitosan/PEO-LiTFSI films have been prepared by the solution cast technique. The highest conductivity at room temperature was 1.4 × 10−6 Scm−1 and the activation energy was 0.47 eV for chitosan/PEO blends containing 30 wt.% LiTFSI salts. The conductivity of the samples is dependent on the number of mobile ions.

From crab shell to solar cell: a gel polymer electrolyte based on N-phthaloylchitosan and its application in dye-sensitized solar cells

Chitosan, a biopolymer derived from crab shells which is insoluble in common organic solvents has been converted to the organosoluble N-phthaloylchitosan (PhCh) by reaction with phthalic anhydride in dimethylformamide (DMF). The formation and structure of PhCh was confirmed by the characteristic peaks of phthalimido and aromatic groups observed at 719, 1708 and 1772 cm−1 and two sets of peaks centered at 3.0 and 7.5 ppm obtained from FTIR and 1H NMR analyses respectively. Gel polymer electrolytes consisting of PhCh, ethylene carbonate (EC), and DMF with various amounts of tetrapropylammonium iodide (TPAI) and iodine were prepared. The interaction behavior between polymer–plasticizer–salt was thoroughly investigated using FTIR spectroscopy. The gel polymer electrolyte consisting of PhCh : EC : DMF : TPAI : I2 in a weight ratio (g) of 0.1 : 0.3 : 0.3 : 0.12 : 0.012 showed the highest conductivity of 5.46 × 10−3 S cm−1 at room temperature and exhibited the best performance in DSSCs with efficiency of 5.0%, with JSC of 12.72 mA cm−2, VOC of 0.60 V and fill factor of 0.66.

Green synthesis of in situ electrodeposited rGO/MnO2 nanocomposite for high energy density supercapacitors.

This paper presents the preparation of in situ electrodeposited rGO/MnO2 nanocomposite as a binder-free electrode for supercapacitor application. The work describes and evaluates the performance of prepared electrode via green and facile electrodeposition technique of in situ rGO/MnO2-glucose carbon nanocomposites. The carbon content in the composite electrode increased after GO and D (+) glucose solution has been added in the deposition electrolyte. This study found that a suitable concentration of D (+) glucose in the deposition electrolyte can slow down the nucleation process of MnO2 particles and lead to uniform and ultrathin nanoflakes structure. The optimize electrode exhibited low transfer resistance and resulted on excellent electrochemical performance in three electrolyte systems viz. Na2SO4, KOH and KOH/K3Fe(CN)6 redox electrolytes. The optimum energy density and power density were 1851 Whkg−1 and 68 kWkg−1 at current density of 20 Ag−1 in mixed KOH/K3Fe(CN)6 electrolyte.

Characterizations of Chitosan-Based Polymer Electrolyte Photovoltaic Cells

The membranes 55 wt.% chitosan-45 wt.% , 33 wt.% chitosan-27 wt.% -40 wt.% EC, and 27.5 wt.% chitosan-22.5 wt.% -50 wt.% buthyl-methyl-imidazolium-iodide (BMII) exhibit conductivity of , , and S , respectively, at room temperature. These membranes have been used in the fabrication of solid-state solar cells with configuration ITO//polymer electrolyte membrane/ITO. It is observed that the short-circuit current density increases with conductivity of the electrolyte. The use of anthocyanin pigment obtained by solvent extraction from black rice and betalain from the callus of Celosia plumosa also helps to increase the short-circuit current.

Ion-Conducting Membranes Based on Gelatin and Containing LiI/I-2 for Electrochromic Devices

Ionic conducting membranes of gelatin plasticized with glycerol and containing LiI/I2 have been obtained and characterized by X-ray diffraction measurements, UV-Vis-NIR spectroscopy, thermal analysis and impedance spectroscopy. The transparent (80–90% in the visible range) membranes showed ionic conductivity value of 5 × 10−5 S/cm at room temperature, which increased to 3 × 10−3 S/cm at 80°C. All the ionic conductivity measurements as a function of temperature showed VTF dependence and activation energy of 8 kJ/mol. These samples also showed low glass transition temperature of −76°C. Moreover the samples were predominantly amorphous. The membranes applied to small electrochromic devices showed 20% of color change from colored to bleached states during more than 70 cronoamperometric cycles.

Conductivity studies on plasticised PEO/chitosan proton conducting polymer electrolyte

Abstract The effect of ethylene sulphite (ES) content on the conductivity, morphology and nature of polymer electrolytes based on polyethylene oxide (PEO) and chitosan blend doped with ammonium nitrate (NH4NO3) has been analysed in this study. The films produced by the solution cast technique were kept in a desiccator filled with silica gel before characterisation. The sample (23·8 wt-%PEO+35·7 wt-% chitosan)–39·7 wt-%NH4 NO3–0·8 wt-%ES exhibited the highest room temperature conductivity of the order 10–4 s cm–1. The conductivity–temperature relationship was found to obey Arrhenius rule. The activation energy for the highest conducting sample is 0·02 eV. From Jonschers universal power law, the trend of exponent s v. temperature showed that the conduction mechanism of the ions in the highest conducting sample can be explained by the quantum mechanical tunnelling (QMT) model. Scanning electron microscopy (SEM) revealed that surfaces of samples containing ES are porous.

Transference number and structural analysis of proton conducting polymer electrolyte based on poly(ϵ-caprolactone)

Abstract Poly(ϵ-caprolactone) (PCL) is used as the polymer host to dissociate ammonium thiocyanate (NH4SCN). Free standing solid polymer electrolytes of varied weight ratios are prepared by solution casting technique with tetrahydrofuran as solvents. Impedance measurement shows the highest ionic conductivity achieved at room temperature is 1·01×10−4 S cm−1 for PCL incorporated with 26 wt-% NH4SCN. In transference number analysis, the total ionic transference number is calculated to be 0·966 using blocking electrode cell configuration. The value of t+ is evaluated to be 0·21 using reversible electrode cell configuration. The ohmic portion of steady state current indicates the existence of mobile ion pairs or higher aggregates. In X-ray diffraction analysis, crystalline peaks were deconvoluted from the continuous halo with high goodness of fit. The degree of crystallinity as a function of salt concentration is estimated and is in exact agreement with ionic conductivity variation, concluding that accommodation of salt into the polymer matrix depresses the crystalline phase of PCL.