Displaying publications 1 - 20 of 147 in total

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  1. AZRILAWANI AHMAD, NUR ANIS ZAFIRAH ZAINORDIN, NUR AMIRA JAAFAR
    MyJurnal
    A preliminary assessment of a simple and rapid electrochemical method was carried out to analyse imidacloprid (IMI) in water samples using cyclic voltammetry (CV) based on modified screen-printed gold electrode (SPGE). Self-assembled monolayer (SAM) was optimized using 11-mercaptoundecanoic acid (11-MUA) with several parameters such as scan rates, type of supporting electrolyte, and pH of the supporting electrolyte. The modified SPGE showed high suppressed current against the potential due to the formation of a monolayer on the electrode surface. Surface morphology of the electrode was analysed using Scanning Electron Microscopy (SEM) confirming that 11-MUA was present on the modified SPGE. The water samples were collected from GM Peladang, Kuala Terengganu and two locations at Universiti Malaysia Terengganu. Method detection limit was expressed as limit of detection (LOD) and limit of quantification (LOQ) for modified SPGE which were calculated at 3.784 and 12.613 mg/L in water samples, respectively. This study showed that the reduction peak current observed on the modified electrode was lower compared with oxidation peak current. Hence, gold is unsuitable for IMI detection.
    Matched MeSH terms: Electrolytes
  2. Abdul Aziz Ahmad, Raihan Othman, Faridah Yusof, Mohd Firdaus Abdul Wahab
    Sains Malaysiana, 2014;43:459-465.
    A hybrid biofuel cell, a zinc-air cell employing laccase as the oxygen reduction catalyst is investigated. A simple cell design is employed; a membraneless single chamber and a freely suspended laccase in the buffer electrolyte. The cell is characterised based on its open-circuit voltage, power density profile and galvanostatic discharge at 0.5 mA. The activity of laccase as an oxidoreductase is substantiated from the cell discharge profiles. The use of air electrode in the cell design enhanced the energy output by 14%. The zinc-air biofuel cell registered an open-circuit voltage of 1.2 V and is capable to deliver a maximum power density of 1.1 mWcm-2 at 0.4 V. Despite its simple design features, the power output is comparable to that of biocatalytic cell utilising a much more complex system design.
    Matched MeSH terms: Electrolytes
  3. Abdul Keyon AS, Guijt RM, Bolch CJ, Breadmore MC
    J Chromatogr A, 2014 Oct 17;1364:295-302.
    PMID: 25223612 DOI: 10.1016/j.chroma.2014.08.074
    The accumulation of paralytic shellfish toxins (PSTs) in contaminated shellfish is a serious health risk making early detection important to improve shellfish safety and biotoxin management. Capillary electrophoresis (CE) has been proven as a high resolution separation technique compatible with miniaturization, making it an attractive choice in the development of portable instrumentation for early, on-site detection of PSTs. In this work, capillary zone electrophoresis (CZE) with capacitively coupled contactless conductivity detector (C(4)D) and UV detection were examined with counter-flow transient isotachophoresis (tITP) to improve the sensitivity and deal with the high conductivity sample matrix. The high sodium concentration in the sample was used as the leading ion while l-alanine was used as the terminating electrolyte (TE) and background electrolyte (BGE) in which the toxins were separated. Careful optimization of the injected sample volume and duration of the counter-flow resulted in limit of detections (LODs) ranging from 74.2 to 1020 ng/mL for tITP-CZE-C(4)D and 141 to 461 ng/mL for tITP-CZE-UV, an 8-97 fold reduction compared to conventional CZE. The LODs were adequate for the analysis of PSTs in shellfish samples close to the regulatory limit. Intra-day and inter-day repeatability values (percentage relative standard deviation, n=3) of tITP-CZE-C(4)D and tITP-CZE-UV methods for both migration time and peak height were in the range of 0.82-11% and 0.76-10%, respectively. The developed method was applied to the analysis of a contaminated mussel sample and validated against an Association of Official Analytical Chemists (AOAC)-approved method for PSTs analysis by high performance liquid chromatography (HPLC) with fluorescence detection (FLD) after pre-column oxidation of the sample. The method presented has potential for incorporation in to field-deployable devices for the early detection of PSTs on-site.
    Matched MeSH terms: Electrolytes
  4. Abidin MSZ, Matsumura R, Anisuzzaman M, Park JH, Muta S, Mahmood MR, et al.
    Materials (Basel), 2013 Nov 06;6(11):5047-5057.
    PMID: 28788375 DOI: 10.3390/ma6115047
    We report the crystallization of electrodeposited germanium (Ge) thin films on n-silicon (Si) (100) by rapid melting process. The electrodeposition was carried out in germanium (IV) chloride: propylene glycol (GeCl₄:C₃H₈O₂) electrolyte with constant current of 50 mA for 30 min. The measured Raman spectra and electron backscattering diffraction (EBSD) images show that the as-deposited Ge thin film was amorphous. The crystallization of deposited Ge was achieved by rapid thermal annealing (RTA) at 980 °C for 1 s. The EBSD images confirm that the orientations of the annealed Ge are similar to that of the Si substrate. The highly intense peak of Raman spectra at 300 cm(-1) corresponding to Ge-Ge vibration mode was observed, indicating good crystal quality of Ge. An additional sub peak near to 390 cm(-1) corresponding to the Si-Ge vibration mode was also observed, indicating the Ge-Si mixing at Ge/Si interface. Auger electron spectroscopy (AES) reveals that the intermixing depth was around 60 nm. The calculated Si fraction from Raman spectra was found to be in good agreement with the value estimated from Ge-Si equilibrium phase diagram. The proposed technique is expected to be an effective way to crystallize Ge films for various device applications as well as to create strain at the Ge-Si interface for enhancement of mobility.
    Matched MeSH terms: Electrolytes
  5. Abu Bakar K, Jalaludin MY, Zainal N, Woon SL, Mohd Zikre N, Samingan N, et al.
    Front Pediatr, 2021;9:655010.
    PMID: 34026690 DOI: 10.3389/fped.2021.655010
    Introduction: Many reports on investigations and treatments in UTI, however little, have been mentioned with regard to electrolyte abnormalities. Secondary pseudohypoaldosteronism (PHA) in UTI, though less common, is a known association. Features include hyponatremia and concomitant hyperkalemia. Objectives: We aim to highlight these uncommon sequelae in UTI to avoid incorrect diagnosis and unnecessary investigations. Study Design: Clinical data of patients admitted and referred to a pediatric nephrologist at the University Malaya Medical Center between May 2019 and October 2020 were collated and elaborated. Results and Discussion: We report three infants with hyponatremia and hyperkalemia during UTI episodes. Two infants were known to have posterior urethral valve (PUV) before the onset of UTI and one infant had UTI, which led to investigations confirming the diagnosis of bladder vaginal fistula. The electrolyte derangements were temporary and resolved within 48 to 72 h of treatment with intravenous fluid and appropriate antibiotic therapy. Out of three, only one had a hormonal study, which confirms PHA. Reduced aldosterone activity could be due to absolute reduction in aldosterone titer or lack of aldosterone responsiveness at tubular (other tissues) level. In the latter, aldosterone titer is elevated. The infant in our cohort who had hormonal evaluation had the mentioned electrolyte abnormalities with a markedly elevated aldosterone titer. This demonstrated defective action of the hormone at the level of mineralocorticoid receptor. Although the remaining two infants had no confirmatory hormonal study, all of them recovered within 48 h of hospital admission, after receiving appropriate management for the primary problem, which was UTI. We observed a slower recovery of hyponatremia in relation to hyperkalemia, but none of these infants required salt replacement upon discharge. Conclusion: Infants with severe UTI and deranged electrolytes should be screened for structural abnormality and vice versa. Not all infants require hormonal screening, but those who required prolonged salt replacement or showed involvement of other systems warrant further evaluation.
    Matched MeSH terms: Electrolytes
  6. Abu Bakar MH, Azeman NH, Mobarak NN, Mokhtar MHH, A Bakar AA
    Polymers (Basel), 2020 Sep 08;12(9).
    PMID: 32911662 DOI: 10.3390/polym12092040
    This research demonstrates a one-step modification process of biopolymer carrageenan active sites through functional group substitution in κ-carrageenan structures. The modification process improves the electronegative properties of κ-carrageenan derivatives, leading to enhancement of the material's performance. Synthesized succinyl κ-carrageenan with a high degree of substitution provides more active sites for interaction with analytes. The FTIR analysis of succinyl κ-carrageenan showed the presence of new peaks at 1068 cm-1, 1218 cm-1, and 1626 cm-1 that corresponded to the vibrations of C-O and C=O from the carbonyl group. A new peak at 2.86 ppm in 1H NMR represented the methyl proton neighboring with C=O. The appearance of new peaks at 177.05 and 177.15 ppm in 13C NMR proves the substitution of the succinyl group in the κ-carrageenan structure. The elemental analysis was carried out to calculate the degree of substitution with the highest value of 1.78 at 24 h of reaction. The XRD diffractogram of derivatives exhibited a higher degree of crystallinity compared to pristine κ-carrageenan at 23.8% and 9.2%, respectively. Modification of κ-carrageenan with a succinyl group improved its interaction with ions and the conductivity of the salt solution compared to its pristine form. This work has a high potential to be applied in various applications such as sensors, drug delivery, and polymer electrolytes.
    Matched MeSH terms: Electrolytes
  7. Adibah, I., Khursiah, D., Ahmad, A.I., Zaki, N.N.M.
    MyJurnal
    Introduction: The aim of treatment for hyperemesis gravidarum is to stop vomiting, correction of dehydration, starvation and electrolytes imbalance. The common types of fluid used for fluid replacement are isotonic solutions like normal saline and hartman's solutions. The absence of potassium in normal saline makes hartman's solution superior but there is a possibility that the lactate component in hartman's solution could worsen the starvation state of the patients. This study is to evaluate which of these two solutions is more effective for fluid replacement in hyperemesis gravidarum. The objectives are to compare which solution corrects dehydration, hypokalaemia and acetonuria faster and to evaluate whether the ketosis state is aggravated by lactate component in hartman's solution. Materials and Methods: Patients with hyperemesis gravidarum were randomised to receive either Hartman's solution or normal saline at the rate of 125mls/hour. Blood urea and serum electrolytes, haematocrit, lactate and urine acetone were taken during admission and repeated every 12 hours. The volume of fluid required to correct dehydration, hypokalaemia and acetonuria were compared. Comparison of the pre and post treatment level of serum lactate were also done. Results: Both hartman's solution and normal saline are both effective in correcting dehydration (11.52±3.28 pints versus 11.94 ± 2.30pints respectively) and acetonuria (11.64 ± 2.75 pints versus 11.64 ± 2.54 pints respectively).
    A lower volume of hartman's solution was needed to correct hypokalaemia (8.34 ± 2.44 pints versus 8.88 ± 2.63 pints) but was not statistically significant. Ketonaemia was not made worse after treatment with hartman's solution. Conclusion: Normal saline and hartman's solution are equally effective in treating complications of hyperemesis gravidarum.
    Matched MeSH terms: Electrolytes
  8. Ahmad NH, Isa MIN
    Carbohydr Polym, 2016 Feb 10;137:426-432.
    PMID: 26686147 DOI: 10.1016/j.carbpol.2015.10.092
    Two solid biopolymer electrolytes (SBEs) systems of carboxymethyl cellulose doped ammonium chloride (CMC-AC) and propylene carbonate plasticized (CMC-AC-PC) were prepared via solution casting technique. The ionic conductivity of SBEs were analyzed using electrical impedance spectroscopy (EIS) in the frequency range of 50 Hz-1 MHz at ambient temperature (303K). The highest ionic conductivity of CMC-AC SBE is 1.43 × 10(-3)S/cm for 16 wt.% of AC while the highest conductivity of plasticized SBE system is 1.01 × 10(-2)S/cm when added with 8 wt.% of PC. TGA/DSC showed that the addition of PC had increased the decomposition temperature compared of CMC-AC SBE. Fourier transform infrared (FTIR) spectra showed the occurrence of complexation between the SBE components and it is proved successfully executed by Gaussian software. X-ray diffraction (XRD) indicated that amorphous nature of SBEs. It is believed that the PC is one of the most promising plasticizer to enhance the ionic conductivity and performance for SBE system.
    Matched MeSH terms: Electrolytes/chemistry*
  9. Ahmed Asrity S, Tsan FY, Ding P, Syed Aris S
    Sains Malaysiana, 2014;43:1471-1475.
    Phaleria macrocarpa seeds are rapidly killed with desiccation to moisture content (MC) below 20%. Desiccation tolerance of their embryonic axes was studied for storage and germplasm conservation purposes. Embryonic axes were extracted aseptically from fresh seeds obtained from fully ripe fruits in a horizontal laminar air flow cabinet. They were then desiccated under aseptic condition for periods ranging from 0-8 h. For each desiccation treatment, embryonic axes were drawn randomly for the determination of MC according to ISTA, electrolyte leakage and proliferation on Murashige and Skoog (MS) media supplemented with 1 mg/l 6-benzylaminopurine (BAP) and 1 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D). The results obtained from this study indicated that the embryonic axes could tolerate dehydration down to 13.6% with desiccation for 8 h while retaining relatively high viability of 76.7%. This was supported by only gradual increment of electrolyte leakage with the desiccated embryonic axes. All non-desiccated embryonic axes with MC of 52.5% were capable to grow into normal plantlets in vitro but dehydration to MC of 36.0% and further down to 13.6% generally resulted in callus formation with up to 16.7% of the embryonic axes while at least 60.0% of the other embryonic axes were still capable to proliferate as normal plantlets in vitro.
    Matched MeSH terms: Electrolytes
  10. Al Zoubi OM, Normah MN
    Cryo Letters, 2015 Nov-Dec;36(6):379-91.
    PMID: 26963884
    To further understand the survival characteristics of desiccation-sensitive excised embryonic axes of Fortunella polyandra to desiccation and cryopreservation it is necessary to study the impact of drying rates on both the ultrastructure and electrolyte leakage.
    Matched MeSH terms: Electrolytes
  11. Al-Aqil A, Zulkifli I
    Poult Sci, 2009 Jul;88(7):1358-64.
    PMID: 19531704 DOI: 10.3382/ps.2008-00554
    An experiment was conducted to determine the effects of 2 types of housing systems and early age feed restriction on heat shock protein (hsp) 70 expression and blood parameters in broiler chickens subjected to road transportation. On d 1, female chicks were housed either in windowless environmentally controlled chambers (temperature was set at 32 degrees C on d 1 and gradually reduced to 23 degrees C by d 21; CH) or in conventional open-sided houses (OH) with cyclic temperatures (minimum, 24 degrees C; maximum, 34 degrees C). Equal number of chicks from each housing system were subjected to either ad libitum feeding or 60% feed restriction on d 4, 5, and 6 (FR). On d 42, all of the birds were crated and transported for 6 h. Birds raised in OH had smaller increases in heterophil:lymphocyte ratios and plasma corticosterone concentrations than those of CH. Subjecting birds to FR dampened heterophil:lymphocyte ratios and corticosterone reactions to transportation. After 4 h of transportation, the OH birds had greater hsp 70 expression than their CH counterparts. Within the CH, the FR chicks showed higher hsp 70 density than those of the ad libitum-fed group. Except for glucose, housing system had a negligible effect on serum levels of cholesterol, potassium, and chloride. Collectively, the results suggest that the improved tolerance to transport stress in OH and FR chicks could be associated with better hsp 70 expression.
    Matched MeSH terms: Electrolytes/blood
  12. Al-Khalqi EM, Abdul Hamid MA, Al-Hardan NH, Keng LK
    Sensors (Basel), 2021 Mar 17;21(6).
    PMID: 33802968 DOI: 10.3390/s21062110
    For highly sensitive pH sensing, an electrolyte insulator semiconductor (EIS) device, based on ZnO nanorod-sensing membrane layers doped with magnesium, was proposed. ZnO nanorod samples prepared via a hydrothermal process with different Mg molar ratios (0-5%) were characterized to explore the impact of magnesium content on the structural and optical characteristics and sensing performance by X-ray diffraction analysis (XRD), atomic force microscopy (AFM), and photoluminescence (PL). The results indicated that the ZnO nanorods doped with 3% Mg had a high hydrogen ion sensitivity (83.77 mV/pH), linearity (96.06%), hysteresis (3 mV), and drift (0.218 mV/h) due to the improved crystalline quality and the surface hydroxyl group role of ZnO. In addition, the detection characteristics varied with the doping concentration and were suitable for developing biomedical detection applications with different detection elements.
    Matched MeSH terms: Electrolytes
  13. Amir S, Mohamed N, Hashim Ali S
    Sains Malaysiana, 2011;40:1123-1127.
    Due to their high ionic conductivity, solid polymer electrolyte (SPE) systems have attracted wide spread attention as the most appropriate choice to fabricate all-solid-state electrochemical devices, namely batteries, sensors and fuel cells. In this work, ion conductive polymer electrolyte membranes have been prepared for battery fabrication. However, fractals were found to grow in these polymer electrolyte membranes weeks after they were prepared. It was believed that the formation of fractal aggregates in these membranes were due to ionic movement. The discovery of fractal growth pattern can be used to understand the effects of such phenomenon in the polymer electrolyte membranes. Digital images of the fractal growth patterns were taken and a simulation model was developed based on the Brownian motion theory and a fractal dialect known as L-system. A computer coding has been designed to simulate and visualize the fractal growth.
    Matched MeSH terms: Electrolytes
  14. Amir S, Othman R, Subban R, Mohamed N
    Sains Malaysiana, 2011;40:1179-1186.
    Solid polymer electrolytes comprised of various weight percent ratios of poly(ethyl methacrylate) (PEMA) and lithium perchlorate (LiClO4) salt were prepared via solution casting technique using N,N-dimethylformamide (DMF) as the solvent. The conductivity values of the electrolytes were determined via impedance spectroscopy. The conductivity of the PEMA-LiClO4 electrolytes increased with increasing salt concentration and the highest conductivity obtained was in the order of 10-6 S cm-1 at salt concentration of 20 wt%. The conductivity decreased for higher salt concentration. In order to understand the conductivity behavior, XRD and dielectric studies were done. The results showed that the conductivity was influenced by the fraction of amorphous region and number of charge carriers in the system. The transference number measurement was also performed on the highest conducting electrolyte systems. The result of the measurement indicated that the systems were ionic conductors.
    Matched MeSH terms: Electrolytes
  15. Aniza Omar, Ainnur Sherene Kamisan, Muhd Zu Azhan bin Yahya, Siti Zafirah Zainal Abidin, Ab Malik Marwan Ali, Siti Irma Yuana Saaid
    MyJurnal
    Magnesium-based polymer gel electrolytes consist of magnesium triflate (MgTf) salt, a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) solvents as well as cellulose acetate as a polymeric agent were prepared via direct dissolution method. The highest ionic conductivity obtained for MgTf-EC:DEC(1:1) liquid electrolytes was 2.66 x 10-3 S cm-1 and enhanced to 2.73 x 10-3 S cm-1 with the addition of cellulose acetate. These results were in agreement with the activation energy obtained with the lowest value of 0.11. The best explanation on the enhancement in ionic conductivity of PGE is due to the “breathing polymeric chain model”. The plots of conductivity-temperature shown to obey an Arrhenius rule. The electrical properties of the sample with the highest conductivity were analyzed using electrical permittivity-based frequency and temperature dependence in the range of 100 Hz - 1 MHz and 303-373K, respectively. The variation in dielectric permittivity (εr and εi) as a function of frequency at different temperatures exhibited decays at higher frequencies and a dispersive behavior at low frequencies. Based on the observed electrical properties, it can be inferred that this polymer gel electrolyte could be a promising candidate as an electrolyte in electrochemical devices.
    Matched MeSH terms: Electrolytes
  16. Asaithambi P, Aziz ARA, Sajjadi B, Daud WMABW
    Environ Sci Pollut Res Int, 2017 Feb;24(6):5168-5178.
    PMID: 27221586 DOI: 10.1007/s11356-016-6909-5
    In the present work, the efficiency of the sonication, electrocoagulation, and sono-electrocoagulation process for removal of pollutants from the industrial effluent of the pulp and paper industry was compared. The experimental results showed that the sono-electrocoagulation process yielded higher pollutant removal percentage compared to the sonication and electrocoagulation process alone. The effect of the operating parameters in the sono-electrocoagulation process such as electrolyte concentration (1-5 g/L), current density (1-5 A/dm(2)), effluent pH (3-11), COD concentration (1500-6000 mg/L), inter-electrode distance (1-3 cm), and electrode combination (Fe and Al) on the color removal, COD removal, and power consumption were studied. The maximum color and COD removal percentages of 100 and 95 %, respectively, were obtained at the current density of 4 A/dm(2), electrolyte concentration of 4 g/L, effluent pH of 7, COD concentration of 3000 mg/L, electrode combination of Fe/Fe, inter-electrode distance of 1 cm, and reaction time of 4 h, respectively. The color and COD removal percentages were analyzed by using an UV/Vis spectrophotometer and closed reflux method. The results showed that the sono-electrocoagulation process could be used as an efficient and environmental friendly technique for complete pollutant removal.
    Matched MeSH terms: Electrolytes
  17. Asif M, Jabeen Q, Abdul-Majid AM, Atif M
    Pak J Pharm Sci, 2014 Nov;27(6):1811-7.
    PMID: 25362605
    The aim of the study was to evaluate the effect of crude aqueous extract of Boswellia serrata Roxb. oleo gum on urinary electrolytes, pH and diuretic activity in normal albino rats. Moreover, acute toxicity of the gum extract was assessed using mice. Albino rats were divided into five groups. Control group received normal saline (10 mg/kg), reference group received furosemide (10 mg/kg) and test groups were given different doses of crude extract (10, 30 and 50 mg/kg) by intra-peritoneal route, respectively. The Graph Pad Prism was used for the statistical analysis and p < 0.05 was considered statistically significant. Significant diuretic, kaliuretic and natriuretic effects were observed in the treated groups in a dose dependent manner. Diuretic index showed good diuretic activity of the crude extract. Lipschitz values indicated that the crude extract, at the dose of 50 mg/kg, showed 44 % diuretic activity compared to the reference drug. No lethal effects were observed among albino mice even at the higher dose of 3000 mg/kg. It is concluded that aqueous extract of Boswellia serrata oleo gum, at the dose of 50 mg/kg showed significant effects on urinary volume and concentration of urinary electrolytes with no signs of toxicity.
    Matched MeSH terms: Electrolytes/urine
  18. Asnawi ASFM, B Aziz S, M Nofal M, Hamsan MH, Brza MA, Yusof YM, et al.
    Polymers (Basel), 2020 Jun 26;12(6).
    PMID: 32604910 DOI: 10.3390/polym12061433
    In this study, the solution casting method was employed to prepare plasticized polymer electrolytes of chitosan (CS):LiCO2CH3:Glycerol with electrochemical stability (1.8 V). The electrolyte studied in this current work could be established as new materials in the fabrication of EDLC with high specific capacitance and energy density. The system with high dielectric constant was also associated with high DC conductivity (5.19 × 10-4 S/cm). The increase of the amorphous phase upon the addition of glycerol was observed from XRD results. The main charge carrier in the polymer electrolyte was ion as tel (0.044) < tion (0.956). Cyclic voltammetry presented an almost rectangular plot with the absence of a Faradaic peak. Specific capacitance was found to be dependent on the scan rate used. The efficiency of the EDLC was observed to remain constant at 98.8% to 99.5% up to 700 cycles, portraying an excellent cyclability. High values of specific capacitance, energy density, and power density were achieved, such as 132.8 F/g, 18.4 Wh/kg, and 2591 W/kg, respectively. The low equivalent series resistance (ESR) indicated that the EDLC possessed good electrolyte/electrode contact. It was discovered that the power density of the EDLC was affected by ESR.
    Matched MeSH terms: Electrolytes
  19. Asnawi ASFM, Aziz SB, Brevik I, Brza MA, Yusof YM, Alshehri SM, et al.
    Polymers (Basel), 2021 Jan 26;13(3).
    PMID: 33530553 DOI: 10.3390/polym13030383
    The polymer electrolyte system of chitosan/dextran-NaTf with various glycerol concentrations is prepared in this study. The electrical impedance spectroscopy (EIS) study shows that the addition of glycerol increases the ionic conductivity of the electrolyte at room temperature. The highest conducting plasticized electrolyte shows the maximum DC ionic conductivity of 6.10 × 10-5 S/cm. Field emission scanning electron microscopy (FESEM) is used to investigate the effect of plasticizer on film morphology. The interaction between the electrolyte components is confirmed from the existence of the O-H, C-H, carboxamide, and amine groups. The XRD study is used to determine the degree of crystallinity. The transport parameters of number density (n), ionic mobility (µ), and diffusion coefficient (D) of ions are determined using the percentage of free ions, due to the asymmetric vibration (υas(SO3)) and symmetric vibration (υs(SO3)) bands. The dielectric property and relaxation time are proved the non-Debye behavior of the electrolyte system. This behavior model is further verified by the existence of the incomplete semicircle arc from the Argand plot. Transference numbers of ion (tion) and electron (te) for the highest conducting plasticized electrolyte are identified to be 0.988 and 0.012, respectively, confirming that the ions are the dominant charge carriers. The tion value are used to further examine the contribution of ions in the values of the diffusion coefficient and mobility of ions. Linear sweep voltammetry (LSV) shows the potential window for the electrolyte is 2.55 V, indicating it to be a promising electrolyte for application in electrochemical energy storage devices.
    Matched MeSH terms: Electrolytes
  20. Awang N, Jaafar J, Ismail AF
    Polymers (Basel), 2018 Feb 15;10(2).
    PMID: 30966230 DOI: 10.3390/polym10020194
    Void-free electrospun SPEEK/Cloisite15A® densed (SP/e-spunCL) membranes are prepared. Different loadings of Cloisite15A® (0.10, 0.15, 0.20, 0.25 and 0.30 wt %) are incorporated into electrospun fibers. The physico-chemical characteristics (methanol permeability, water uptake and proton conductivity) of the membranes are observed. Thermal stability of all membranes is observed using Thermal Gravimetry Analysis (TGA). The thrree stages of degradation range between 163.1 and 613.1 °C. Differential Scanning Calorimetry (DSC) is used to study the wettability of the membranes. SP/e-spunCL15 shows the lowest freezing bound water of 15.27%, which contributed to the lowest methanol permeability. The non-freezing bound water that proportionally increased with proton conductivity of SP/e-spunCL15 membrane is the highest, 10.60%. It is suggested that the electrospinning as the fabricating method has successfully exfoliated the Cloisite in the membrane surface structure, contributing to the decrease of methanol permeability, while the retained water has led to the enhancement of proton conductivity. This new fabrication method of SP/e-spunCL membrane is said to be a desirable polymer electrolyte membrane for future application in direct methanol fuel cell field.
    Matched MeSH terms: Electrolytes
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