NOWADAYS, FABRICATION OF SUPERCAPACITORS OR ELECTROCHEMICAL CAPACITORS (ECS) BY USING FLEXIBLE MATERIAL BECAUSE OF ITS EASY TRANSPORTABILITY, WEARABLE, LOW WEIGHT AND BULK IS CONSIDERED [1]. IN THIS STUDY, SUPER CAPACITORS WERE ASSEM- BLED BY ENTANGLING ALKALINE POLYVINYL ALCOHOL AND POTASSIUM HYDROXIDE (PVA-KOH) IN THE PRESENCE AND ABSENCE OF POTASSIUM IODIDE (KI) AS GEL ELECTROLYTES BETWEEN NANOSILVER FLEXIBLE ELECTRODES (NSFES).THE NSFES WAS PREPARED WITH CHEMICAL DEPOSITION OF NANOSILVER PARTICLES ONTO PAPER SUBSTRATE VIA INKJET PRINTING METHOD [2]. THE GEL ELECTROLYTES WAS PREPARED BY A SOLUTIONCASTING METHOD, WHERE NSFES AS CURRENT COLLECTORS AND THE GEL ELECTROLYTES WERE USED AS BOTH SEPARATOR AND ELECTROLYTE [3]. THEN, ELECTROCHEMICAL PROPERTIES OF SUPER-CAPACITOR WERE INVESTIGATED BY CYCLIC VOLTAMMETRY AND GALVANOSTATE CHARGE-DISCHARGE TECHNIQUES.THE ELECTROCHEMICAL CELL USED WAS EQUIPPED WITH NSFES AS WORKING ELECTRODES AND AN AUXILIARY ELECTRODE, A SATURATED CALOMEL ELECTRODE (SCE) AS A REFERENCE ELECTRODE. FINALLY, THE EFFECT OF KI PRESENCE ON THE SUPER CAPACITOR CAPACITY WAS STUDIED. THE KI CONCENTRATION FOR ACHIEVING A GOOD CAPACITY WAS OPTIMIZED AND THE BEHAVIOR OF SUPERCAPACITOR AT DIFFERENT SCAN RATES WAS EVALUATED. ACCORDING TO RESULTS, SPECIFIC CAPACITANCE 0.22FG-1 OBTAINED BY USING GALVANOSTATE CHARGE-DISCHARGE TECHNIQUE. THIS TOLERABLE CAPACITANCE OBTAINED BY KI PRESENCE IN ELECTROLYTE. INDEED, KI ACTS AS A MEDIATED-REDOX AND INCREASE PSEUDOCAPACITANCES OF SUPERCAPACITOR BY FARADIC REACTIONS. OPTIMUM CONCENTRATION 0.072M EARND FOR KI IN ELECTROLYTE. THE STUDY OF SUPERCAPACITOR AT DIFFERENT SCAN RATES FROM 5-35 MVS-1 EXHIBITS A PLOT OF PEAK HEIGHT (IP) AGAINST SQUARE ROOT OF SCAN RATE (V1/2), WHICH WAS FOUND TO BE LINEAR, SUGGESTING THAT AT SUFFICIENT OVER POTENTIAL THE PROCESS IS DIFFUSION RATHER THAN SURFACE CONTROLLED. ENERGY DENSITY AND POWER DENSITY FOR THE SUPER CAPACITOR IN PRESENCE 0.072M KI OBTAINED 0.8´10-6 WH KG-1 AND 17W KG-1, RESPECTIVELY.

BACKGROUND: SINCE DYE-SENSITIZED SOLAR CELL (DSSC) WAS INVENTED BY PROF GRATZEL IN 1991, THIS TYPE OF PHOTOVOLTAIC DEVICE HAS BEEN ATTRACTED GREAT ATTENTION DUE TO ITS LOW-COST MATERIALS AND EASY FABRICATION. BECAUSE OF USING LIQUID ELECTROLYTES; THE STABILITY OF DSSC HAS BEEN AFFECTED BY SOLVENT EVAPORATION AND LEAKAGE OF LIQUID ELECTROLYTE, SO REPLACEMENT OF LIQUID ELECTROLYTE BY A POLYMER GEL ELECTROLYTE HAS BEEN PROPOSED FOR OVERCOMING THESE PROBLEMS. BIOPOLYMERS HAVE RECEIVED MORE ATTENTION BECAUSE OF THEIR VARIETY ABUNDANCE IN NATURE, NO TOXICITY AND BIODEGRADABILITY [1, 2] IN COMPARISON TO CHEMICAL POLYMERS. IN THIS WORK WE HAVE USED CHITOSAN AS A BIOPOLYMER IN COMPOSITION OF ELECTROLYTE FOR DSSC AND THE PERFORMANCE OF THE CELL HAS BEEN INVESTIGATED.METHOD: DSSCS WHICH WAS FABRICATED IN THIS WORK INCLUDE A POROUS NANO CRYSTALLINE TIO2 FILM SENSITIZED BY N719 ON SUBSTRATE OF FLUORINE-DOPED SNO2 AS PHOTOANODE, I- AND I3- COUPLE IN CHITOSAN SOLUTION AS ELECTROLYTE AND PLATINIZED FTO AS CATHODE. I3- COMES FROM THE REACTION OF I- WITH I2, SO 0.362 GR OF NH4I AND 0.127 GR OF I2 WAS DISSOLVED IN 25 ML ACETONITRILE, 20 ML OF THIS SOLUTION WERE ADDED TO 25 ML CHITOSAN SOLUTION (FOR PREPARING CHITOSAN SOLUTION 1 GR OF CHITOSAN WAS DISSOLVED IN 100 ML ACETIC ACID 1%) DROP BY DROP. THE FINAL SOLUTION (NH4I 0.044 M AND I2 0.0089 M) WAS USED FOR FABRICATION OF DSSC. CURRENT DENSITYVOLTAGE CURVE OF THE CELL WAS OBTAINED BY POTENTIOSTAT GALVANOSTAT EQUIPMENT UNDER ILLUMINATION OF LIGHT INTENSITY CORRESPONDING TO 100W/CM2.RESULT: THE CHITOSAN GEL ELECTROLYTE DSSC SHOWED EFFICIENCY OF 0.76% WITH SHORT - CIRCUIT DENSITY (JSC) OF 2.03MA/CM2 OPEN CIRCUIT VOLTAGE (VOC) OF 0.66 V AND FILL FACTOR OF 0.56.CONCLUSION: STABILITY AND LONG TERM OPERATION OF THE DSSCS ARE FUTURE CRISIS FOR COMMERCIALIZATION OF THESES PHOTOVOLTAIC DEVICE. AS THE EFFICIENCY OBTAINED WITH SOLID STATE ELECTROLYTES ARE LOW FOR LARGE SCALE PRODUCTION OF DSSCS, UTILIZATION OF GEL ELECTROLYTE IS PROPOSED AS A STRATEGIES FOR COMMERCIALIZATION OF DSSCS. FOR THIS PURPOSE, A DSSC CONTAINING GEL ELECTROLYTE BASED ON CHITOSAN BIOPOLYMER WAS CONSTRUCTED. THE RESULTS SHOWED IN COMPARISON WITH CELL HAVING LIQUID ELECTROLYTE, THE STABILITY OF CELL WAS HIGHER BUT BECAUSE OF THE HIGHER VISCOSITY OF ELECTROLYTE THE PERFORMANCE OF CELL WAS LOW. THESE RESULTS ARE HOPEFUL AND CAN BOOST ADDITIONAL STUDIES ORIENTED TO THE SEARCH OF NEW GEL ELECTROLYTE AND TO THE OPTIMIZATION OF GEL ELECTROLYTE COMPONENTS WITH CHITOSAN.

PBI (POLYBENZIMIDAZOLE) -MNTIO3 (PMT) NANOCOMPOSITE MEMBRANES HAVE BEEN PREPARED WITH SOLUTIONS CASTING METHOD. THE NANOCOMPOSITE MEMBRANES WERE CHARACTERIZED BY USING AC IMPEDANCE SPECTROSCOPY (IS), FOURIER TRANSFORM INFRARED SPECTROSCOPY (FT-IR), SCANNING ELECTRON MICROSCOPY (SEM) COUPLED WITH ENERGY DISPERSIVE X-RAY (EDX) AND THERMOGRAVIMETRIC ANALYSIS (TGA). THE RESULTS SHOWED THAT THE WATER UPTAKE AND PROTON CONDUCTIVITY OF THE PMT NANOCOMPOSITE MEMBRANES WERE HIGHER THAN THAT OF PBI BASED MEMBRANE BECAUSE OF HYDROPHILIC NATURE OF MNTIO3 NANOPARTICLES. WHEN THE PREPARED MEMBRANES DOPED WITH PHOSPHORIC ACID (PA), DUE TO PROTON TRANSFER FROM PA, PA-PMT NANOCOMPOSITE MEMBRANES DISPLAYED HIGHER PROTON CONDUCTIVITY THAN PMT NANOCOMPOSITE MEMBRANES. INCORPORATION OF NANOPARTICLES IN NANOCOMPOSITE MEMBRANES INCREASED THE THERMAL STABILITY OF PA-PMT NANOCOMPOSITE MEMBRANES COMPARED WITH PA-PBI MEMBRANES.

EFFICIENT OPERATION OF PROTON EXCHANGE MEMBRANE FUEL CELL (PEMFC) IS CRITICALLY ASSOCIATED TO EFFECTIVE COOLING SYSTEM. DESIGNING A COOLING SYSTEM REQUIRES SIGNIFICANT CHALLENGES IN REGARD TO THE NARROW RANGE OF OPERATING TEMPERATURES. IN THIS EFFORT, NEW COOLING FLOW FIELDS ARE NUMERICALLY INVESTIGATED IN ORDER TO CLARIFY THE SUFFICIENT DESIGN FOR THE HEAT REMOVAL. NUMERICAL SIMULATION IS APPLIED TO INVESTIGATE THE COOLANT FLOW DISTRIBUTION AND THERMAL BEHAVIOR OF DIFFERENT MODELS. THE TEMPERATURE CONTOURS REPRESENT THE TEMPERATURE UNIFORMITY FOR THE ASSESSED CASES.

IN THIS WORK, BAZRO3 NANOPARTICLES AS MIXED METAL OXIDES, WITH PROVISION OF STRONG ACID SITES AND GOOD HYDROPHILIC NATURE WERE USED FOR THE PREPARATION OF ORGANIC-INORGANIC PROTON EXCHANGE MEMBRANES. PVA (POLY VINYL ALCOHOL) -BAZRO3 (PB) AND PVA-PVP (POLY VINYL PYRROLIDONE) - BAZRO3 (PPB) NANOCOMPOSITE MEMBRANES HAVE BEEN PREPARED WITH SOLUTIONS CASTING METHOD. GLUTARALDEHYDE (GA) WAS USED AS CROSS LINKING AGENT. THE NANOCOMPOSITE MEMBRANES WERE CHARACTERIZED BY USING AC IMPEDANCE SPECTROSCOPY (IS), FOURIER TRANSFORM INFRARED SPECTROSCOPY (FT-IR), SCANNING ELECTRON MICROSCOPY (SEM) COUPLED WITH ENERGY DISPERSIVE X-RAY (EDX), THERMOGRAVIMETRIC ANALYSIS (TGA) AND TENSILE STRENGTH (TS). THE RESULTS SHOWED THAT THE GOOD WATER UPTAKE AND PROTON CONDUCTIVITY OF THE PB AND PPB NANOCOMPOSITE MEMBRANES RESPECT TO THE PVA BASED MEMBRANE. PPB NANOCOMPOSITE MEMBRANES CONTAINING 1 WT % OF BAZRO3 NANOPARTICLES DEMONSTRATED HIGH WATER UPTAKE (230%) AND PROTON CONDUCTIVITY (1.85×10-2 S/CM).