Rosnah Zakaria

Effects of Sodium Iodide (NaI) on Electro-Conductivity with Polyurethane-Diol Organic Electrolyte for Dye-Sensitized Solar Cell (DSSC)

Dye Sensitized Solar Cells (DSSC) technology using inorganic electrolytes post problem in solvent evaporation and iodine sublimation (corroding contacts) causing instability of cells. Application of low molecular oligomers is progressing recently for an improved performance. The electrolyte system was aimed for improving electrochemical stability using quasi-solid-state electrolytes from organic capped polymers. A photo-electrochemical cell was developed from bio-based polyurethane diol (PU) polymer electrolyte with Sodium iodide (NaI) as conducting electrolyte transport material. In this study, polyurethane-diol was modified with NaI cations in the hydrothermal chemical reaction to form modified polyurethane-diol electrolyte. The chemical structure of polyurethane-diol and NaI have achieved highest conductivity of 8.06x10-5 S.cm-1 where structural of polyurethane-diol with NaI shown redox Fermi vectorial energy transfer evaluated for performance of efficiency. Stable cell for DSSC system require material properties to be invidually optimized in views of various elemential performances and solar cell of FTO/TiO-Pc/PU-NaI-I2/Ac give a response under light intensity of 100 mW cm−2 and indicated efficiency of power generation of 4 mW where photovoltaic effect of current density, Jsc of 0.04 mA.cm−2 and open circuit voltage, Voc of 0.4 V respectively.

X-Ray Diffraction and Infrared Studies on Plasticized Cellulose Acetate Complexed with Ammonium Iodide for Solid Polymer Electrolyte

Gel polymer electrolyte films based on cellulose acetate (CA) complexed with ammonium iodide (NH4I), and ethylene carbonate (EC) was prepared by the solution cast technique. The conductivity increases to 10-4 Scm-1 upon the addition of salt. The incorporation of EC and to the salted polymer enhances the conductivity significantly 10-3 Scm-1. The complexation of doping materials with polymer was confirmed by X-ray diffraction and infrared studies. The present of ethylene carbonate (EC) as plasticizer did not disturbed the complexation between polymer and salt that has been confirm by FTIR. XRD studies further confirmed that all sample prepared are crystalline. This result affirmed that there were no complexations occur between plasticizer in the CA-NH4I polymer system.

Rheology behaviour of modified silicone-dammar as a natural resin coating

Modified silicone-dammar (SD) was prepared by various weight percent from 5 – 45 wt% of dammar added. The n-value (viscosity index) of silicone with 5 and 10 % were turn to be 1.6 and 1.3 of viscosity index. While 15, 20, 25 and 30 wt% of dammar added gave 0.7, 0.3, 0.2 and 0.1 of viscosity index. On the other hand, 35, 40 and 45 wt% of dammar gave a fixed value of viscosity index of 0.03. This n-value shows the dispersion quality of paint mixture indicates that the modified silicone-dammar was followed the Bingham’s Model. The rheology measurement of SD mixture was analysed by plotting ln shear stress vs shear rate value. Analysis of the graph showed a Bingham plastic model with regression R2 equivalent to 0.99. The linear viscoelastic behaviour of SD samples increased in parallel with increasing dammar content indicate that the suspension of dammar in silicone resin could flow steadily with time giving a pseudoplastic behaviour.

Comparative Studies on Li/LiI-Li2WO4-Li3PO4/Metal Oxide Electrochemical Cells

A series of experiment has been carried out to study the electrochemical performances of lithium primary cells using different cathode materials. The cathode material was made of metal oxide, electrolyte, activated carbon, and PVdF with a wt. ratio of 60: 20:10:10. PVdF was added as a binder. The metal oxides used are MnO2 and V2O5. The anode was made up of lithium metal and LiI-Li2WO4-Li3PO4 compound is used as an electrolyte. In this work the open circuit voltage (OCV) of Li/MnO2 and Li/V2O5 obtained is about 3.0 V and 3.2 V respectively. This shows that LiI-Li2WO4-Li3PO4 compound is lithium ion conductor. Lithium cell showed better performance at 100º C than at room temperature. Among these two types of cells investigated, cell Li/V2O5 worked better than the Li/MnO2 cell at room temperature and at 100°C as this cell exhibits the longest continuous discharge time and the highest OCV.

Correlation studies between surface tension energy and ionic mobility in silicone - Dammar thin film for dye sensitized solar cells

Organic thin film system consisting of Silicone-dammar (SD) polymer resin was prepared and studied with respect to their electrochemical properties. Dammar which is a local plant resin (Dipterocaupacea sp) was mixed with silicone in various compositions and the two components were modified by using a solvent. A thin film layered on glass slaid was obtained by Doctor Blade method and cured at room temperature. Silicone-dammar with a composition ratio of 80:20 (SD20) showed the highest non-wetting angle at 90.13 degrees however the sample with a composition ratio of 90:10 (SD10) showed the highest surface tension energy at 179.80 J in the contact angle test. Electrochemical Impedance Spectroscopy (EIS) analysis was done to investigate the electron transport and it was found that the SD10 sample provides a good medium for ionic mobility.

Scratch Hatch and Nanoscratch Evaluation of Silicone-Dammar Coating as Soft Coating Resin Materials

Viscosity and rheological investigation are preliminary investigation to identify the mixture behaviour. The investigation found that SD mixtures behave like pseudoplastic behaviour and this showed that the mixture is the right solution to be a paint mixture. Scratch hatch is a conventional method to measure the adhesion of dried coating. SD15, SD10 and SD5 were showed the smooth edges of the cut. However, nanoscratch test is a high technology method measure the minimum depth of penetration on SD40 followed by SD25, SD15 and SD5. This showed that the SD40 is the hardest coating film. As for all adhesion performance, SD15 becoming the best coating film with medium standard evaluation.

Electrical Properties of Ammonium Iodide Doped Cellulose Acetate Based Polymer Electrolyte

Solid Polymer Electrolyte (SPEs) composed of cellulose acetate (CA) doped with different stoichiometric ratio of ammonium iodide (NH4I) was study. Alternating current impedance spectroscopy was carried out in the frequency range between 50 Hz and 1 MHz at room and elevated temperatures. The highest ionic conductivity obtained from the complex impedance spectra of the order of 10−4 S cm−1 at room temperature with the polymer-salt composition of CA (75 wt%):NH4I (25 wt%). Temperature dependence of the conductivity for all samples studied was of the Arrhenius type. Modulus formalism analysis verified the samples are ionic conductor and was confirmed by electronic transference number. X-ray diffraction spectral analysis showed the introduction of doping salt was decreased the degree of crystallinity of polymer host.

Comparative studies on Li/Lil-Li2WO4-Li 3PO4/metal oxide electrochemical cells

, A series of experiment has been carried out to study the electrochemical performances of lithium primary cells using different cathode materials. The cathode material was made of metal oxide, electrolyte, activated carbon, and PVdF with a wt. ratio of 60: 20:10:10. PVdF was added as a binder. The metal oxides used are MnO 2 and V 2 O 5 . The anode was made up of lithium metal and LiI-Li 2 WO 4 -Li 3 PO 4 compound is used as an electrolyte. In this work the open circuit voltage (OCV) of Li/MnO 2 and Li/V 2 O 5 obtained is about 3.0 V and 3.2 V respectively. This shows that LiI-Li 2 WO 4 -Li 3 PO 4 compound is lithium ion conductor. Lithium cell showed better performance at 100° C than at room temperature. Among these two types of cells investigated, cell Li/V 2 O 5 worked better than the Li/MnO 2 cell at room temperature and at 100°C as this cell exhibits the longest continuous discharge time and the highest OCV.