Displaying publications 61 - 80 of 142 in total

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  1. Fulltext Polyelectrolytes ability in reducing atrazine concentration in water: surface effects
    Mohd Amin MF, Heijman SG, Lopes SI, Rietveld LC
    ScientificWorldJournal, 2014;2014:162157.
    PMID: 25197693 DOI: 10.1155/2014/162157
    This paper reports on the direct ability of two positively charged organic polyelectrolytes (natural-based and synthetic) to reduce the atrazine concentration in water. The adsorption study was set up using multiple glass vessels with different polymer dosing levels followed by ultrafiltration with a 1 kDa membrane. The addition of polymers exhibited a capability in reducing the atrazine concentration up to a maximum of 60% in surface-to-volume ratio experiments. In the beginning, the theoretical L-type of the isotherm of Giles' classification was expected with an increase in the dosage of the polymer. However, in this study, the conventional type of isotherm was not observed. It was found that the adsorption of the cationic polymer on the negatively charged glass surface was necessary and influential for the removal of atrazine. Surface-to-volume ratio adsorption experiments were performed to elucidate the mechanisms and the polymer configuration. The glass surface area was determined to be a limiting parameter in the adsorption mechanism.
    Matched MeSH terms: Electrolytes/chemistry*
  2. Characterization of conducting cellulose acetate based polymer electrolytes doped with "green" ionic mixture
    Ramesh S, Shanti R, Morris E
    Carbohydr Polym, 2013 Jan 2;91(1):14-21.
    PMID: 23044100 DOI: 10.1016/j.carbpol.2012.07.061
    Polymer electrolytes were developed by solution casting technique utilizing the materials of cellulose acetate (CA), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and deep eutectic solvent (DES). The DES is synthesized from the mixture of choline chloride and urea of 1:2 ratios. The increasing DES content well plasticizes the CA:LiTFSI:DES matrix and gradually improves the ionic conductivity and chemical integrity. The highest conducting sample was identified for the composition of CA:LiTFSI:DES (28 wt.%:12 wt.%:60 wt.%), which has the greatest ability to retain the room temperature ionic conductivity over the entire 30 days of storage time. The changes in FTIR cage peaks upon varying the DES content in CA:LiTFSI:DES prove the complexation. This complexation results in the collapse of CA matrix crystallinity, observed from the reduced intensity of XRD diffraction peaks. The DES-plasticized sample is found to be more heat-stable compared to pure CA. Nevertheless, the addition of DES diminishes the CA:LiTFSI matrix's heat-resistivity but at the minimum addition the thermal stability is enhanced.
    Matched MeSH terms: Electrolytes/chemistry*
  3. Conductivity and FTIR studies on PEO-LiX [X: CF3SO3(-), SO4(2-)] polymer electrolytes
    Ramesh S, Yuen TF, Shen CJ
    Spectrochim Acta A Mol Biomol Spectrosc, 2008 Feb;69(2):670-5.
    PMID: 17600757
    Polymer electrolytes based on poly(ethylene oxide)-lithium triflate (PEO-LiCF3SO3) and poly(ethylene oxide)-lithium sulphate (PEO-Li2S4) were prepared by using solution casting method. Measurements of conductivity and dielectric were carried out on these films as a function of frequency at various temperatures. It was observed that PEO-LiCF3SO3 polymer electrolytes have higher conductivity. The interaction between PEO and Li salts were studied by Fourier transform infrared (FTIR).
    Matched MeSH terms: Electrolytes/chemistry*
  4. FTIR studies of PVC/PMMA blend based polymer electrolytes
    Ramesh S, Leen KH, Kumutha K, Arof AK
    Spectrochim Acta A Mol Biomol Spectrosc, 2007 Apr;66(4-5):1237-42.
    PMID: 16919998
    The polymer electrolytes composing of the blend of polyvinyl chloride-polymethyl methacrylate (PVC/PMMA) with lithium triflate (LiCF3SO3) as salt, ethylene carbonate (EC) and dibutyl phthalate (DBP) as plasticizers and silica (SiO2) as the composite filler were prepared. FTIR studies confirm the complexation between PVC/PMMA blends. The CCl stretching mode at 834 cm-1 for pure PVC is shifted to 847 cm-1 in PVC-PMMA-LiCF3SO3 system. This suggests that there is interaction between Cl in PVC with Li+ ion from LiCF3SO3. The band due to OCH3 at 1150 cm-1 for PVC-PMMA blend is shifted to 1168 cm-1 in PVC-PMMA-LiCF3SO3 system. This shift is expected to be due to the interaction between Li+ ion and the oxygen atom in PMMA. The symmetric vibration band and the asymmetric vibration band of LiCF3SO3 at 1033 and 1256 cm-1 shifted to 1075 and 1286 cm-1 in the DBP-EC plasticized PVC-PMMA-LiCF3SO3 complexes. The interaction between Li+ ions and SiO2 will lead to an increase in the number of free plasticizers (which does not interact with Li+ ions). When the silica content increases from 2% to 5%, the intensity of the peak at 896 cm-1 (due to the ring breathing vibration of free EC) increases in PVC-PMMA-LiCF3SO3-DBP-EC system.
    Matched MeSH terms: Electrolytes/chemistry*
  5. FTIR spectra of plasticized grafted natural rubber-LiCF3SO3 electrolytes
    Kumutha K, Alias Y
    Spectrochim Acta A Mol Biomol Spectrosc, 2006 May 15;64(2):442-7.
    PMID: 16530471
    Chemical modification of natural rubber (NR) has frequently been attempted to improve the performance in specific application. 30% poly(methyl metacrylate) (PMMA) grafted into NR (MG30) has been explored as a potential candidate for polymer electrolytes. The complexation effect of salt and plasticizer in polymer host electrolytes had been investigated using FTIR. The carbonyl stretch of MG30 locates at 1729 cm-1, with the addition of lithium trimethanesulfonate (LiCF3SO3) salt, new band evolves at lower frequency region at 1643-1645 cm-1. The nondegenerate vibrational mode of nus(SO3) of salted electrolytes appearing at 1031-1034 cm-1 comes from 'free' trimethanesulfonate anions and the 1040-1046 cm-1 absorption from the monodentate ion paired with triflates. These indicate MG30-salt interaction. When MG30 and ethylene carbonate (EC) formed film, the CH3 asymmetric bend of MG30 appearing at 1447cm-1 is shifted to 1449 cm-1 in the EC-polymer complex. The CO stretching at 1729 cm-1 also shifted to 1728 cm-1. Hence, the EC-MG30 system is complexed to each other. EC-LiCF3SO3 interactions are indicated by the shifting of CO bending band of EC from 718 cm-1 being shifted to 720 cm-1 in the complex. In Li+-EC interaction where the ring breathing region at 897 cm-1 in EC has shifted to 899 cm-1 in EC-salt spectrum. The band appearing at 1643-1645 cm-1 due to the coordination of Li+
    Matched MeSH terms: Electrolytes/chemistry*
  6. Radiation and temperature effects on conductivity properties of PVA-KOH-PC composite
    Mohd Asri MT, Elias S, Iskandar SM, Abd Halim S, Jumiah H, Zaki AR, et al.
    Med J Malaysia, 2004 May;59 Suppl B:139-40.
    PMID: 15468857
    The aim of this work was to study radiation and the effects of temperature on conductivity properties of polyvinyl alcohol (PVA)-based potassium hydroxide (KOH) and propylene carbonate (PC), where the ionic conduction preferentially occurs in the amorphous phase by free radicals ions through gamma-irradiation. Alkaline composite polymer electrolyte (ACPE) consisting of PVA, KOH and PC of different concentration ratios were prepared by solvent-casting technique. The ACPE were irradiated with different doses from 5 kGy up to 200 kGy. The conductivity properties of the electrolyte films were measured at different frequencies in the range 20 Hz to 1 MHz using LCR meter. The results showed that the conductivity properties were dependent on the radiation dose, temperature and the concentration of the polymer blends.
    Matched MeSH terms: Electrolytes/radiation effects*
  7. Fulltext Layer by Layer Ex-Situ Deposited Cobalt-Manganese Oxide as Composite Electrode Material for Electrochemical Capacitor
    Rusi, Chan PY, Majid SR
    PLoS One, 2015;10(7):e0129780.
    PMID: 26158447 DOI: 10.1371/journal.pone.0129780
    The composite metal oxide electrode films were fabricated using ex situ electrodeposition method with further heating treatment at 300°C. The obtained composite metal oxide film had a spherical structure with mass loading from 0.13 to 0.21 mg cm(-2). The structure and elements of the composite was investigated using X-ray diffraction (XRD) and energy dispersive X-ray (EDX). The electrochemical performance of different composite metal oxides was studied by cyclic voltammetry (CV) and galvanostatic charge-discharge (CD). As an active electrode material for a supercapacitor, the Co-Mn composite electrode exhibits a specific capacitance of 285 Fg(-1) at current density of 1.85 Ag(-1) in 0.5 M Na2SO4 electrolyte. The best composite electrode, Co-Mn electrode was then further studied in various electrolytes (i.e., 0.5 M KOH and 0.5 M KOH/0.04 M K3Fe(CN) 6 electrolytes). The pseudocapacitive nature of the material of Co-Mn lead to a high specific capacitance of 2.2 x 10(3) Fg(-1) and an energy density of 309 Whkg(-1) in a 0.5 M KOH/0.04 M K3Fe(CN) 6 electrolyte at a current density of 10 Ag(-1). The specific capacitance retention obtained 67% of its initial value after 750 cycles. The results indicate that the ex situ deposited composite metal oxide nanoparticles have promising potential in future practical applications.
    Matched MeSH terms: Electrolytes/chemistry
  8. Electrical, structural, thermal and electrochemical properties of corn starch-based biopolymer electrolytes
    Liew CW, Ramesh S
    Carbohydr Polym, 2015 Jun 25;124:222-8.
    PMID: 25839815 DOI: 10.1016/j.carbpol.2015.02.024
    Biopolymer electrolytes containing corn starch, lithium hexafluorophosphate (LiPF6) and ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF6) are prepared by solution casting technique. Temperature dependence-ionic conductivity studies reveal Vogel-Tamman-Fulcher (VTF) relationship which is associated with free volume theory. Ionic liquid-based biopolymer electrolytes show lower glass transition temperature (Tg) than ionic liquid-free biopolymer electrolyte. X-ray diffraction (XRD) studies demonstrate higher amorphous region of ionic liquid-added biopolymer electrolytes. In addition, the potential stability window of the biopolymer electrolyte becomes wider and stable up to 2.9V. Conclusively, the fabricated electric double layer capacitor (EDLC) shows improved electrochemical performance upon addition of ionic liquid into the biopolymer electrolyte. The specific capacitance of EDLC based on ionic liquid-added polymer electrolyte is relatively higher than that of ionic liquid-free polymer electrolyte as depicted in cyclic voltammogram.
    Matched MeSH terms: Electrolytes/chemistry*
  9. Fulltext The Study of Electrical and Electrochemical Properties of Magnesium Ion Conducting CS: PVA Based Polymer Blend Electrolytes: Role of Lattice Energy of Magnesium Salts on EDLC Performance
    Aziz SB, Brza MA, Hamsan EMADMH, Hadi JM, Kadir MFZ, Abdulwahid RT
    Molecules, 2020 Oct 01;25(19).
    PMID: 33019618 DOI: 10.3390/molecules25194503
    Plasticized magnesium ion conducting polymer blend electrolytes based on chitosan (CS): polyvinyl alcohol (PVA) was synthesized with a casting technique. The source of ions is magnesium triflate Mg(CF3SO3)2, and glycerol was used as a plasticizer. The electrical and electrochemical characteristics were examined. The outcome from X-ray diffraction (XRD) examination illustrates that the electrolyte with highest conductivity exhibits the minimum degree of crystallinity. The study of the dielectric relaxation has shown that the peak appearance obeys the non-Debye type of relaxation process. An enhancement in conductivity of ions of the electrolyte system was achieved by insertion of glycerol. The total conductivity is essentially ascribed to ions instead of electrons. The maximum DC ionic conductivity was measured to be 1.016 × 10-5 S cm-1 when 42 wt.% of plasticizer was added. Potential stability of the highest conducting electrolyte was found to be 2.4 V. The cyclic voltammetry (CV) response shows the behavior of the capacitor is non-Faradaic where no redox peaks appear. The shape of the CV response and EDLC specific capacitance are influenced by the scan rate. The specific capacitance values were 7.41 F/g and 32.69 F/g at 100 mV/s and 10 mV/s, respectively. Finally, the electrolyte with maximum conductivity value is obtained and used as electrodes separator in the electrochemical double-layer capacitor (EDLC) applications. The role of lattice energy of magnesium salts in energy storage performance is discussed in detail.
    Matched MeSH terms: Electrolytes/chemistry*
  10. Cervical fluid pH, electrolytes and osmolarity changes and expression of ion transporters (ENaC, CFTR and AQP) in cervix of women with primary unexplained infertility
    Ismail N, Myint K, Khaing SL, Giribabu N, Salleh N
    Mol Biol Rep, 2023 Aug;50(8):6729-6737.
    PMID: 37382776 DOI: 10.1007/s11033-023-08555-6
    BACKGROUND: Unexplained infertility could arise from a defect in the cervix. However, the contribution of abnormal cervical fluid microenvironment to this problem still needs to be identified. Therefore, this study identifies the changes in the cervical fluid microenvironment, i.e., pH, electrolytes and osmolarity as well as expression of ion transporters in the cervix including ENaC, CFTR and AQP in fertile women and in women suffering from primary unexplained infertility.

    METHODS: Fertile women and women with unexplained infertility but having regular 28-day menstrual cycles were chosen in this study, Day-22 serum progesterone levels were determined. In the meantime, serum FSH and LH levels were determined on day 2 while, cervical flushing was performed at day 14 to analyse changes in the cervical fluid pH, osmolarity, Na+ and Cl- levels. Meanwhile, cells retrieved from cervical fluid were subjected to mRNA expression and protein distribution analysis for CFTR, AQP and ENaC by qPCR and immunofluorescence, respectively.

    RESULTS: No significant changes in serum progesterone, FSH and LH levels were observed between the two groups. However, cervical fluid pH, osmolarity, Na+ and Cl- levels were significantly lower in primary unexplained infertile group when compared to fertile group. Expression of CFTR and AQP (AQP 1, AQP 2, AQP 5 and AQP 7) in endocervical cells was lower and expression of β-ENaC was higher in primary unexplained infertile women (p 

    Matched MeSH terms: Electrolytes/metabolism
  11. Fulltext Synthesis and characterization of modified κ-carrageenan for enhanced proton conductivity as polymer electrolyte membrane
    Liew JWY, Loh KS, Ahmad A, Lim KL, Wan Daud WR
    PLoS One, 2017;12(9):e0185313.
    PMID: 28957374 DOI: 10.1371/journal.pone.0185313
    Polymer electrolyte membranes based on the natural polymer κ-carrageenan were modified and characterized for application in electrochemical devices. In general, pure κ-carrageenan membranes show a low ionic conductivity. New membranes were developed by chemically modifying κ-carrageenan via phosphorylation to produce O-methylene phosphonic κ-carrageenan (OMPC), which showed enhanced membrane conductivity. The membranes were prepared by a solution casting method. The chemical structure of OMPC samples were characterized using Fourier transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance (1H NMR) spectroscopy and 31P nuclear magnetic resonance (31P NMR) spectroscopy. The conductivity properties of the membranes were investigated by electrochemical impedance spectroscopy (EIS). The characterization demonstrated that the membranes had been successfully produced. The ionic conductivity of κ-carrageenan and OMPC were 2.79 × 10-6 S cm-1 and 1.54 × 10-5 S cm-1, respectively. The hydrated membranes showed a two orders of magnitude higher ionic conductivity than the dried membranes.
    Matched MeSH terms: Electrolytes/chemistry*
  12. Fulltext Effect of solution pH and adsorbent concentration on the sensing parameters of TGN-based electrochemical sensor
    Rahmani M, Ghafoorifard H, Afrang S, Ahmadi MT, Rahmani K, Ismail R
    IET Nanobiotechnol, 2019 Aug;13(6):584-592.
    PMID: 31432790 DOI: 10.1049/iet-nbt.2018.5288
    The response of trilayer graphene nanoribbon (TGN)-based ion-sensitive field-effect transistor (ISFET) to different pH solutions and adsorption effect on the sensing parameters are analytically studied in this research. The authors propose a TGN-based sensor to electrochemically detect pH. To this end, absorption effect on the sensing area in the form of carrier concentration, carrier velocity, and conductance variations are investigated. Also, the caused electrical response on TGN as a detection element is analytically proposed, in which significant current decrease of the sensor is observed after exposure to high pH values. In order to verify the accuracy of the model, it is compared with recent reports on pH sensors. The TGN-based pH sensor exposes higher current compared to that of carbon nanotube (CNT) counterpart for analogous ambient conditions. While, the comparative results demonstrate that the conductance of proposed model is lower than that of monolayer graphene-counterpart for equivalent pH values. The results confirm that the conductance of the sensor is decreased and Vg-min is obviously right-shifted by increasing value of pH. The authors demonstrate that although there is not the experimental evidence reported in the part of literature for TGN sensor, but the model can assist in comprehending experiments involving nanoscale pH sensors.
    Matched MeSH terms: Electrolytes/chemistry*
  13. Fulltext The potential of incorporation of binary salts and ionic liquid in P(VP-co-VAc) gel polymer electrolyte in electrochemical and photovoltaic performances
    Ming NH, Ramesh S, Ramesh K
    Sci Rep, 2016 06 08;6:27630.
    PMID: 27273020 DOI: 10.1038/srep27630
    In this study, dye-sensitized solar cells (DSSCs) has been assembled with poly(1-vinylpyrrolidone-co-vinyl acetate) (P(VP-co-VAc)) gel polymer electrolytes (GPEs) which have been incorporated with binary salt and an ionic liquid. The potential of this combination was studied and reported. The binary salt system GPEs was having ionic conductivity and power conversion efficiency (PCE) that could reach up to 1.90 × 10(-3) S cm(-1) and 5.53%, respectively. Interestingly, upon the addition of the ionic liquid, MPII into the binary salt system the ionic conductivity and PCE had risen steadily up to 4.09 × 10(-3) S cm(-1) and 5.94%, respectively. In order to know more about this phenomenon, the electrochemical impedance studies (EIS) of the GPE samples have been done and reported. Fourier transform infrared studies (FTIR) and thermogravimetric analysis (TGA) have also been studied to understand more on the structural and thermal properties of the GPEs. The Nyquist plot and Bodes plot studies have been done in order to understand the electrochemical properties of the GPE based DSSCs and Tafel polarization studies were done to determine the electrocatalytic activity of the GPE samples.
    Matched MeSH terms: Electrolytes
  14. Fulltext Conductance modulation of charged lipid bilayer using electrolyte-gated graphene-field effect transistor
    Kiani MJ, Harun FK, Ahmadi MT, Rahmani M, Saeidmanesh M, Zare M
    Nanoscale Res Lett, 2014;9(1):371.
    PMID: 25114659 DOI: 10.1186/1556-276X-9-371
    Graphene is an attention-grabbing material in electronics, physics, chemistry, and even biology because of its unique properties such as high surface-area-to-volume ratio. Also, the ability of graphene-based materials to continuously tune charge carriers from holes to electrons makes them promising for biological applications, especially in lipid bilayer-based sensors. Furthermore, changes in charged lipid membrane properties can be electrically detected by a graphene-based electrolyte-gated graphene field effect transistor (GFET). In this paper, a monolayer graphene-based GFET with a focus on the conductance variation caused by membrane electric charges and thickness is studied. Monolayer graphene conductance as an electrical detection platform is suggested for neutral, negative, and positive electric-charged membrane. The electric charge and thickness of the lipid bilayer (Q LP and L LP) as a function of carrier density are proposed, and the control parameters are defined. Finally, the proposed analytical model is compared with experimental data which indicates good overall agreement.
    Matched MeSH terms: Electrolytes
  15. Fulltext Green synthesis of in situ electrodeposited rGO/MnO2 nanocomposite for high energy density supercapacitors
    Rusi, Majid SR
    Sci Rep, 2015;5:16195.
    PMID: 26537363 DOI: 10.1038/srep16195
    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.
    Matched MeSH terms: Electrolytes
  16. Electrodeposited Ge Nanostructures Prepared by Different Non-Aqueous Solutions and their Application in Lithium Ion Battery: A Review
    Nadarajah K, Khan AF, Rahim NA
    Recent Pat Nanotechnol, 2016;10(1):26-43.
    PMID: 27018271
    BACKGROUND: Germanium (Ge) nanostructures exhibit wide range of potential applications in the field of nanoscale devices due to their excellent optical and electrical properties and have gained significant interest due to the Bohr exciton radius. Bohr radius of Ge (24.3 nm) is larger than that of Si (4.9 nm), leading to quantum size effects and nanostructures with controllable bandgaps.

    METHODS: This article provides a comprehensive review on various electrolytes for electrodeposition procedures developed to obtain the Ge nanostructures of desired structure, diameter, and density. We discuss the growth mechanisms and influence of different parameters such as type of solution, concentration, and value of applied potential or current density.

    RESULTS: The ionic liquids can be used for the development of Ge nanostructures and provide extensive electrochemical windows for electrodeposition. The obtained SixGe1-x structures also exhibited strong color change (from red to blue) at room temperature during the electrodeposition, which is likely to be due to a quantum size effect.

    CONCLUSION: The main advantages of the ionic liquids are 'it does not decompose', easy to purify and dry. Moreover, it exhibits fairly extensive electrochemical windows greater than 5 V for electrodeposition. Electrodeposition of SixGe1-x nanostructures from ionic liquids is quite a favorable process. The 3DOM Ge electrode is a promising material for nextgeneration lithium ion battery because of its high irreversible specific capacity. Few relevant patents to the topic have been reviewed and cited.

    Matched MeSH terms: Electrolytes
  17. Vibrational studies of flexible solid polymer electrolyte based on PCL-EC incorporated with proton conducting NH4SCN
    Woo HJ, Arof AK
    Spectrochim Acta A Mol Biomol Spectrosc, 2016 May 15;161:44-51.
    PMID: 26945998 DOI: 10.1016/j.saa.2016.02.034
    A flexible solid polymer electrolyte (SPE) system based on poly(ε-caprolactone) (PCL), a FDA approved non-toxic and biodegradable material in the effort to lower environmental impact was prepared. Ammonium thiocyanate (NH4SCN) and ethylene carbonate (EC) were incorporated as the source of charge carriers and plasticizing agent, respectively. When 50wt.% of ethylene carbonate (EC) was added to PCL-NH4SCN system, the conductivity increased by two orders from of 3.94×10(-7)Scm(-1) to 3.82×10(-5)Scm(-1). Molecular vibrational analysis via infrared spectroscopy had been carried out to study the interaction between EC, PCL and NH4SCN. The relative percentage of free ions, ion pairs and ion aggregates was calculated quantitatively by deconvoluting the SCN(-) stretching mode (2030-2090cm(-1)). This study provides fundamental insight on how EC influences the free ion dissociation rate and ion mobility. The findings are also in good agreement to conductivity, differential scanning calorimetry and X-ray diffraction results. High dielectric constant value (89.8) of EC had made it an effective ion dissociation agent to dissociate both ion pairs and ion aggregates, thus contributing to higher number density of free ions. The incorporation of EC had made the polymer chains more flexible in expanding amorphous domain. This will facilitate the coupling synergy between ionic motion and polymer segmental motion. Possible new pathway through EC-NH4(+) complex sites for ions to migrate with shorter distance has been anticipated. This implies an easier ion migration route from one complex site to another.
    Matched MeSH terms: Electrolytes
  18. CoS2 engulfed ultra-thin S-doped g-C3N4 and its enhanced electrochemical performance in hybrid asymmetric supercapacitor
    Vinoth S, Subramani K, Ong WJ, Sathish M, Pandikumar A
    J Colloid Interface Sci, 2021 Feb 15;584:204-215.
    PMID: 33069019 DOI: 10.1016/j.jcis.2020.09.071
    This work demonstrates a high-performance hybrid asymmetric supercapacitor (HASC) workable in very high current density of 30 A g-1 with in-situ pyrolytic processed sulfur-doped graphitic carbon nitride/cobalt disulfide (S-gC3N4/CoS2) materials and bio-derived carbon configuration and achievement of high electrochemical stability of 89% over 100,000 cycles with the coulombic efficiency of 99.6%. In the electrochemical studies, the S-gC3N4/CoS2-II electrode showed a high specific capacity of 180 C g-1 at 1 A g-1 current density in the half-cell configuration. The HASC cell was fabricated using S-gC3N4/CoS2-II material and orange peel derived activated carbon as a positive and negative electrode with a maximum operating cell potential of 1.6 V, respectively. The fabricated HASC delivered a high energy density of 26.7 Wh kg-1 and power density of 19.8 kW kg-1 in aqueous electrolyte. The prominent properties in specific capacity and cycling stability could be attributed to the CoS2 nanoparticles engulfed into the S-gC3N4 framework which provides short transport distance of the ions, strong interfacial interaction, and improving structural stability of the S-gC3N4/CoS2-II materials.
    Matched MeSH terms: Electrolytes
  19. Fulltext Natural Inspired Carboxymethyl Cellulose (CMC) Doped with Ammonium Carbonate (AC) as Biopolymer Electrolyte
    Sohaimy MIHA, Isa MINM
    Polymers (Basel), 2020 Oct 26;12(11).
    PMID: 33114745 DOI: 10.3390/polym12112487
    Green and safer materials in energy storage technology are important right now due to increased consumption. In this study, a biopolymer electrolyte inspired from natural materials was developed by using carboxymethyl cellulose (CMC) as the core material and doped with varied ammonium carbonate (AC) composition. X-ray diffraction (XRD) shows the prepared CMC-AC electrolyte films exhibited low crystallinity content, Xc (~30%) for sample AC7. A specific wavenumber range between 900-1200 cm-1 and 1500-1800 cm-1 was emphasized in Fourier transform infrared (FTIR) testing, as this is the most probable interaction to occur. The highest ionic conductivity, σ of the electrolyte system achieved was 7.71 × 10-6 Scm-1 and appeared greatly dependent on ionic mobility, µ and diffusion coefficient, D. The number of mobile ions, η, increased up to the highest conducting sample (AC7) but it became less prominent at higher AC composition. The transference measurement, tion showed that the electrolyte system was predominantly ionic with sample AC7 having the highest value (tion = 0.98). Further assessment also proved that the H+ ion was the main conducting species in the CMC-AC electrolyte system, which presumably was due to protonation of ammonium salt onto the complexes site and contributed to the overall ionic conductivity enhancement.
    Matched MeSH terms: Electrolytes
  20. Enhancing the Efficiency of a Dye-Sensitized Solar Cell Based on a Metal Oxide Nanocomposite Gel Polymer Electrolyte
    Saidi NM, Omar FS, Numan A, Apperley DC, Algaradah MM, Kasi R, et al.
    ACS Appl Mater Interfaces, 2019 Aug 21;11(33):30185-30196.
    PMID: 31347822 DOI: 10.1021/acsami.9b07062
    To overcome the critical limitations of liquid-electrolyte-based dye-sensitized solar cells, quasi-solid-state electrolytes have been explored as a means of addressing long-term device stability, albeit with comparatively low ionic conductivities and device performances. Although metal oxide additives have been shown to augment ionic conductivity, their propensity to aggregate into large crystalline particles upon high-heat annealing hinders their full potential in quasi-solid-state electrolytes. In this work, sonochemical processing has been successfully applied to generate fine Co3O4 nanoparticles that are highly dispersible in a PAN:P(VP-co-VAc) polymer-blended gel electrolyte, even after calcination. An optimized nanocomposite gel polymer electrolyte containing 3 wt % sonicated Co3O4 nanoparticles (PVVA-3) delivers the highest ionic conductivity (4.62 × 10-3 S cm-1) of the series. This property is accompanied by a 51% enhancement in the apparent diffusion coefficient of triiodide versus both unmodified and unsonicated electrolyte samples. The dye-sensitized solar cell based on PVVA-3 displays a power conversion efficiency of 6.46% under AM1.5 G, 100 mW cm-2. By identifying the optimal loading of sonochemically processed nanoparticles, we are able to generate a homogenous extended particle network that effectively mobilizes redox-active species through a highly amorphous host matrix. This effect is manifested in a selective 51% enhancement in photocurrent density (JSC = 16.2 mA cm-2) and a lowered barrier to N719 dye regeneration (RCT = 193 Ω) versus an unmodified solar cell. To the best of our knowledge, this work represents the highest known efficiency to date for dye-sensitized solar cells based on a sonicated Co3O4-modified gel polymer electrolyte. Sonochemical processing, when applied in this manner, has the potential to make meaningful contributions toward the ongoing mission to achieve the widespread exploitation of stable and low-cost dye-sensitized solar cells.
    Matched MeSH terms: Electrolytes
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