Displaying publications 1 - 20 of 149 in total

Abstract:
Sort:
  1. Fulltext Influence of Sintering Temperature of Kaolin, Slag, and Fly Ash Geopolymers on the Microstructure, Phase Analysis, and Electrical Conductivity
    Zulkifli NNI, Abdullah MMAB, Przybył A, Pietrusiewicz P, Salleh MAAM, Aziz IH, et al.
    Materials (Basel), 2021 Apr 26;14(9).
    PMID: 33925777 DOI: 10.3390/ma14092213
    This paper clarified the microstructural element distribution and electrical conductivity changes of kaolin, fly ash, and slag geopolymer at 900 °C. The surface microstructure analysis showed the development in surface densification within the geopolymer when in contact with sintering temperature. It was found that the electrical conductivity was majorly influenced by the existence of the crystalline phase within the geopolymer sample. The highest electrical conductivity (8.3 × 10-4 Ωm-1) was delivered by slag geopolymer due to the crystalline mineral of gehlenite (3Ca2Al2SiO7). Using synchrotron radiation X-ray fluorescence, the high concentration Ca boundaries revealed the appearance of gehlenite crystallisation, which was believed to contribute to development of denser microstructure and electrical conductivity.
    Matched MeSH terms: Electric Conductivity
  2. Thermodynamics and solute-solvent interactions of lovastatin in an aqueous arginine solution
    Zolkiflee NF, Affandi MMRMM, Majeed ABA
    Eur J Pharm Sci, 2020 Jan 01;141:105111.
    PMID: 31629916 DOI: 10.1016/j.ejps.2019.105111
    Lovastatin (LVS) is an effective therapeutic and prophylactic agent in several cardiovascular disorders. However, it has low bioavailability. This study investigated solute-solvent and solute-cosolute interactions and assessed thermodynamic parameters that contributed to LVS solubility enhancement in the presence of arginine (ARG) as a hydrotropic agent. The electrolytic conductance of LVS-ARG binary system was measured at temperatures from 298.15 K to 313.15 K. Conductometric parameters such as limiting molar conductance was evaluated. Additionally, thermodynamic parameters (ΔG0, ΔH0, ΔS0 and ES) involved in the association process of the solute in the aqueous solution of ARG solution were determined systematically. Solubility markedly improved 43-fold in the LVS-ARG complex compared to LVS alone. The analysed data from values of molar conductance and activation energy suggested favourable solubilisation, with a stronger solute-solvent interaction between LVS-ARG in water at higher temperatures. ARG and LVS complexation caused by strong molecular interactions was confirmed by spectral results. Hence, the addition of ARG as a co-solute was proven to enhance LVS solubility in water. The obtained data will ultimately enable the development of desired highly soluble, more efficient and safer LVS preparations.
    Matched MeSH terms: Electric Conductivity
  3. Fulltext Quantitative intrinsic auto-cathodoluminescence can resolve spectral signatures of tissue-isolated collagen extracellular matrix
    Zielinski MS, Vardar E, Vythilingam G, Engelhardt EM, Hubbell JA, Frey P, et al.
    Commun Biol, 2019;2:69.
    PMID: 30793047 DOI: 10.1038/s42003-019-0313-x
    By analyzing isolated collagen gel samples, we demonstrated in situ detection of spectrally deconvoluted auto-cathodoluminescence signatures of specific molecular content with precise spatial localization over a maximum field of view of 300 µm. Correlation of the secondary electron and the hyperspectral images proved ~40 nm resolution in the optical channel, obtained due to a short carrier diffusion length, suppressed by fibril dimensions and poor electrical conductivity specific to their organic composition. By correlating spectrally analyzed auto-cathodoluminescence with mass spectroscopy data, we differentiated spectral signatures of two extracellular matrices, namely human fibrin complex and rat tail collagen isolate, and uncovered differences in protein distributions of isolated extracellular matrix networks of heterogeneous populations. Furthermore, we demonstrated that cathodoluminescence can monitor the progress of a human cell-mediated remodeling process, where human collagenous matrix was deposited within a rat collagenous matrix. The revealed change of the heterogeneous biological composition was confirmed by mass spectroscopy.
    Matched MeSH terms: Electric Conductivity
  4. Comparative effects of different soil conditioners on wheat growth and yield grown in saline-sodic soils
    Zia-ur-Rehman M, Sabir M, Shahjahan, Ahmed HR, Muhammad Rizwan, Ali S
    Sains Malaysiana, 2016;45:339-346.
    Among abiotic stresses, salinity is the main abiotic stress limiting crop growth and yield worldwide. Improving agri-food production in salt-prone areas is the key to meet the increasing food demands in near future. A greenhouse experiment was conducted to investigate the effect of different soil conditioners, gypsum (GYP), citric acid (CA), ethylene diamine tetraacetic acid (EDTA) and polyvinyl alcohol (PVA), on growth and yield of wheat (Triticum aestivum L.) grown in salinesodic soil. Gypsum was applied at a rate of 100% soil gypsum requirement while other amendments were applied each at a rate of 5 g kg-1 of soil. The results showed that EDTA treatment increased pH and electrical conductivity (ECe) of soil while pH significantly decreased when treated with citric acid. Soil sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) decreased in all treatments following the order: CT > PVA > EDTA > CA > GYP. Addition of CA positively affected growth parameters as compared to other soil conditioners including plant height, number of tillers per plant, number of spikes per plant, plant dry weight and grain yield while EDTA negatively affected these parameters. Addition of CA also significantly increased photosynthetic rate, stomatal conductance, transpiration rate and chlorophyll contents while EDTA decreased these parameters. We conclude that increase in plant growth and yield with CA might be due to the effect of CA on soil properties which positively affected plant physiological parameters.
    Matched MeSH terms: Electric Conductivity
  5. Fulltext Effect of Root Restriction on the Growth, Photosynthesis Rate, and Source and Sink Relationship of Chilli (Capsicum annuum L.) Grown in Soilless Culture
    Zakaria NI, Ismail MR, Awang Y, Megat Wahab PE, Berahim Z
    Biomed Res Int, 2020;2020:2706937.
    PMID: 32090071 DOI: 10.1155/2020/2706937
    Chilli (Capsicum annum L.) plant is a high economic value vegetable in Malaysia, cultivated in soilless culture containers. In soilless culture, the adoption of small container sizes to optimize the volume of the growing substrate could potentially reduce the production cost, but will lead to a reduction of plant growth and yield. By understanding the physiological mechanism of the growth reduction, several potential measures could be adopted to improve yield under restricted root conditions. The mechanism of growth reduction of plants subjected to root restriction remains unclear. This study was conducted to determine the physiological mechanism of growth reduction of root-restricted chilli plants grown in polyvinyl-chloride (PVC) column of two different volumes, 2392 cm3(root-restricted) and 9570 cm3(control) in soilless culture. Root restriction affected plant growth, physiological process, and yield of chilli plants. Root restriction reduced the photosynthesis rate and photochemical activity of PSII, and increased relative chlorophyll content. Limited root growth in root restriction caused an accumulation of high levels of sucrose in the stem and suggested a transition of the stem as a major sink organ for photoassimilate. Growth reduction in root restriction was not related to limited carbohydrate production, but due to the low sink demand from the roots. Reduction of the total yield per plant about, 23% in root restriction was concomitant, with a slightly increased harvest index which reflected an increased photoassimilate partitioning to the fruit production and suggested more efficient fruits production in the given small plant size of root restriction.
    Matched MeSH terms: Electric Conductivity
  6. Fulltext Electrical conductivity studies in polycrystalline (CuSe)1-x Se x
    Zainal Abidin Talib, Liew, Josephine Ying Chyi, Zulkarnain Zainal, Mahmood Mat Yunus, W., Lim, Kean Pah, Wan M. Daud, Wan Yusoff, et al.
    Pertanika Journal of Science & Technology, 2009;17(1):-.
    MyJurnal
    This studies are directed towards measuring the electrical conductivity of the (CuSe)1-xSex metal chalcogenide semi-conductor composites, with different stoichiometric compositions of Se (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8,1.0) in bulk form. The electrical conductivity measurement was carried out at room temperature, using the parallel plate technique. The (CuSe)1-xSex composites were prepared using solid state reaction, by varying the ratio of CuSe:Se, in the reaction mixture. The electrical conductivity of (CuSe)1-xSex was determined to be in the range of 1.17 x 10-8 to 1.02 x 10-1 S/cm. The finding indicated that the electrical conductivity value tended to decrease as the concentration of Se increased. The effect of the concentration of Se, on electrical conductivity of (CuSe)1-xSex composites, is discussed in this paper.
    Matched MeSH terms: Electric Conductivity
  7. Breast imaging using electrical impedance tomography: correlation of quantitative assessment with visual interpretation
    Zain NM, Chelliah KK
    Asian Pac J Cancer Prev, 2014;15(3):1327-31.
    PMID: 24606460
    BACKGROUND: Electrical impedance tomography (EIT) is a new non-invasive, mobile screening method which does not use ionizing radiation to the human breast; allows conducting quantitative assessment of the images besides the visual interpretation. The aim of this study was to correlate the quantitative assessment and visual interpretation of breast electrical impedance tomographs and associated factors.

    MATERIALS AND METHODS: One hundred and fifty mammography patients above 40 years and undergoing EIT were chosen using convenient sampling. Visual interpretation of the images was carried out by a radiologist with minimum of three years experience using the breast imaging - electrical impedance (BI-EIM) classification for detection of abnormalities. A set of thirty blinded EIT images were reinterpreted to determine the intra-rater reliability using kappa. Quantitative assessment was by comparison of the breast average electric conductivity with the norm and correlations with visual interpretation of the images were determined using Chi-square. One-way ANOVA was used to compare the mean electrical conductivity between groups and t-test was used for comparisons with pre-existing Caucasians statistics. Independent t-tests were applied to compare the mean electrical conductivity of women with factors like exogenous hormone use and family history of breast cancer.

    RESULTS: The mean electrical conductivity of Malaysian women was significantly lower than that of Caucasians (p<0.05). Quantitative assessment of electrical impedance tomography was significantly related with visual interpretation of images of the breast (p<0.05).

    CONCLUSIONS: Quantitative assessment of electrical impedance tomography images was significantly related with visual interpretation.

    Matched MeSH terms: Electric Conductivity
  8. Fulltext Large-scale structure formation in ionic solution and its role in electrolysis and conductivity
    Yee CN, Ooi CHR, Tan LP, Misran M, Tang NT
    PLoS One, 2019;14(3):e0213697.
    PMID: 30913207 DOI: 10.1371/journal.pone.0213697
    That water may not be an inert medium was indicated by the presence at water's interfaces a negatively charged solute free zone of several hundred microns in thickness called the exclusion zone (EZ). Further evidence was demonstrated by Ovchinnikova's experiments (2009) showing that water can store and release substantial amount of charge. We demonstrate that the charge storage capacity of water arises from highly stable large-scale ionic structures with measurable charge imbalances and discrete levels of charge density. We also show evidence that the charge zones formation requires ionic solutes, and their formation correlate to large change in conductivity, by as much as 250%. Our experiments indicate that large-scale structuring plays a pivotal role in electrolysis and conductivity in ionic solution. We propose that water is an electrochemically active medium and present a new model of electrolysis and conductivity in ionic solution.
    Matched MeSH terms: Electric Conductivity
  9. Fulltext Different Concentrations of Doxycycline in Swine Manure Affect the Microbiome and Degradation of Doxycycline Residue in Soil
    Yan Q, Li X, Ma B, Zou Y, Wang Y, Liao X, et al.
    Front Microbiol, 2018;9:3129.
    PMID: 30619199 DOI: 10.3389/fmicb.2018.03129
    Antibiotic residues that enter the soil through swine manure could disturb the number, community structure and functions of microbiota which could also degrade antibiotics in soil. Five different concentrations of doxycycline (DOX) incorporated into swine manure were added to soil to explore the effects of DOX on microbiota in soil and degradation itself. The results showed that the soil microbiome evolved an adaptation to the soil containing DOX by generating resistance genes. Moreover, some of the organisms within the soil microbiome played crucial roles in the degradation of DOX. The average degradation half-life of DOX in non-sterile groups was 13.85 ± 0.45 days, which was significantly shorter than the 29.26 ± 0.98 days in the group with sterilized soil (P < 0.01), indicating that the soil microbiome promoted DOX degradation. DOX addition affected the number of tetracycline resistance genes, depending on the type of gene and the DOX concentration. Among these genes, tetA, tetM, tetW, and tetX had significantly higher copy numbers when the concentration of DOX was higher. In contrast, a lower concentration of DOX had an inhibitory effect on tetG. At the same time, the microbial compositions were affected by the initial concentration of DOX and the different experimental periods. The soil chemical indicators also affected the microbial diversity changes, mainly because some microorganisms could survive in adversity and become dominant bacterial groups, such as the genera Vagococcus and Enterococcus (which were associated with electrical conductivity) and Caldicoprobacter spp. (which were positively correlated with pH). Our study mainly revealed soil microbiota and DOX degradation answered differently under variable concentrations of DOX mixed with swine manure in soil.
    Matched MeSH terms: Electric Conductivity
  10. Fulltext Effect of Reducing Agent on Solution Synthesis of Li3V2(PO4)3 Cathode Material for Lithium Ion Batteries
    Yaghtin A, Masoudpanah SM, Hasheminiasari M, Salehi A, Safanama D, Ong CK, et al.
    Molecules, 2020 Aug 17;25(16).
    PMID: 32824503 DOI: 10.3390/molecules25163746
    In this study, Li3V2(PO4)3 (LVP) powders are prepared by a solution synthesis method. The effects of two reducing agents on crystal structure and morphology and electrochemical properties are investigated. Preliminary studies on reducing agents such as oxalic acid and citric acid, are used to reduce the vanadium (V) precursor. The oxalic acid-assisted synthesis induces smaller particles (30 nm) compared with the citric acid-assisted synthesis (70 nm). The LVP powders obtained by the oxalic acid exhibit a higher specific capacity (124 mAh g-1 at 1C) and better cycling performance (122 mAh g-1 following 50 cycles at 1C rate) than those for the citric acid. This is due to their higher electronic conductivity caused by carbon coating and downsizing the particles. The charge-discharge plateaus obtained from cyclic voltammetry are in good agreement with galvanostatic cycling profiles.
    Matched MeSH terms: Electric Conductivity
  11. Vitamin D3-loaded electrospun cellulose acetate/polycaprolactone nanofibers: Characterization, in-vitro drug release and cytotoxicity studies
    Wsoo MA, Razak SIA, Bohari SPM, Shahir S, Salihu R, Kadir MRA, et al.
    Int J Biol Macromol, 2021 Jun 30;181:82-98.
    PMID: 33771547 DOI: 10.1016/j.ijbiomac.2021.03.108
    Vitamin D deficiency is now a global health problem; despite several drug delivery systems for carrying vitamin D due to low bioavailability and loss bioactivity. Developing a new drug delivery system to deliver vitamin D3 is a strong incentive in the current study. Hence, an implantable drug delivery system (IDDS) was developed from the electrospun cellulose acetate (CA) and ε-polycaprolactone (PCL) nanofibrous membrane, in which the core of implants consists of vitamin D3-loaded CA nanofiber (CAVD) and enclosed in a thin layer of the PCL membrane (CAVD/PCL). CA nanofibrous mat loaded with vitamin D3 at the concentrations of 6, 12, and 20% (w/w) of vitamin D3 were produced using electrospinning. The smooth and bead-free fibers with diameters ranged from 324 to 428 nm were obtained. The fiber diameters increased with an increase in vitamin D3 content. The controlled drug release profile was observed over 30-days, which fit with the zero-order model (R2 > 0.96) in the first stage. The mechanical properties of IDDS were improved. Young's modulus and tensile strength of CAVD/PCL (dry) were161 ± 14 and 13.07 ± 2.5 MPa, respectively. CA and PCL nanofibers are non-cytotoxic based on the results of the in-vitro cytotoxicity studies. This study can further broaden in-vivo study and provide a reference for developing a new IDDS to carry vitamin D3 in the future.
    Matched MeSH terms: Electric Conductivity
  12. Capillary electrophoresis with capacitively coupled contactless conductivity detection for the determination of cis/trans isomers of octadec-9-enoic acid and other long chain fatty acids
    Wong YF, Saad B, Makahleh A
    J Chromatogr A, 2013 May 17;1290:82-90.
    PMID: 23578483 DOI: 10.1016/j.chroma.2013.03.014
    A capillary electrophoresis (CE)-capacitively coupled contactless conductivity detection (C(4)D) method for the simultaneous separation of eleven underivatized fatty acids (FAs), namely, lauric, myristic, tridecanoic (internal standard), pentadecanoic, palmitic, stearic, oleic, elaidic, linoleic, linolenic and arachidic acids is described. The separation was carried out in normal polarity mode at 20 °C, 30 kV and using hydrodynamic injection (50 mbar for 1 s). The separation was achieved in a bare fused-silica capillary (70 cm × 75 μm i.d.) using a background electrolyte of methyl-β-cyclodextrin (~6 mM) and heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (~8 mM) dissolved in a mixture of Na2HPO4/KH2PO4 (5 mM, pH 7.4):ACN:MeOH:n-octanol (3:4:2.5:0.5, v/v/v/v). C(4)D parameters were set at fixed amplitude of 100 V and frequency of 1000 kHz. The developed method was validated. Calibration curves of the ten FAs were well correlated (r(2)>0.99) within the range of 5-250 μg mL(-1) for lauric acid, and 3-250 μg mL(-1) for the other FAs. The method was simple and sensitive with detection limits (S/N=3) of 0.9-1.9 μg mL(-1) and good relative standard deviations of intra- and inter-day for migration times and peak areas (≤9.7%) were achieved. The method was applied to the determination of FAs in margarine samples. The proposed method offers distinct advantages over the GC and HPLC methods, especially in terms of simplicity (without derivatization) and sensitivity.
    Matched MeSH terms: Electric Conductivity
  13. FT-IR studies on interactions among components in hexanoyl chitosan-based polymer electrolytes
    Winie T, Arof AK
    Spectrochim Acta A Mol Biomol Spectrosc, 2006 Mar 1;63(3):677-84.
    PMID: 16157506
    Fourier transform infrared (FT-IR) spectroscopic studies have been undertaken to investigate the interactions among components in a system of hexanoyl chitosan-lithium trifluoromethanesulfonate (LiCF(3)SO(3))-diethyl carbonate (DEC)/ethylene carbonate (EC). LiCF(3)SO(3) interacts with the hexanoyl chitosan to form a hexanoyl chitosan-salt complex that results in the shifting of the N(COR)(2), CONHR and OCOR bands to lower wavenumbers. Interactions between EC and DEC with LiCF(3)SO(3) has been noted and discussed. Evidence of interaction between EC and DEC has been obtained experimentally. Studies on polymer-plasticizer spectra suggested that there is no interaction between the polymer host and plasticizers. Competition between plasticizer and polymer on associating with Li(+) ions was observed from the spectral data for gel polymer electrolytes. The obtained spectroscopic data has been correlated with the conductivity performance of hexanoyl chitosan-based polymer electrolytes.
    Matched MeSH terms: Electric Conductivity
  14. Fulltext MHD free convective boundary layer flow of a nanofluid past a flat vertical plate with Newtonian heating boundary condition
    Uddin MJ, Khan WA, Ismail AI
    PLoS One, 2012;7(11):e49499.
    PMID: 23166688 DOI: 10.1371/journal.pone.0049499
    Steady two dimensional MHD laminar free convective boundary layer flows of an electrically conducting Newtonian nanofluid over a solid stationary vertical plate in a quiescent fluid taking into account the Newtonian heating boundary condition is investigated numerically. A magnetic field can be used to control the motion of an electrically conducting fluid in micro/nano scale systems used for transportation of fluid. The transport equations along with the boundary conditions are first converted into dimensionless form and then using linear group of transformations, the similarity governing equations are developed. The transformed equations are solved numerically using the Runge-Kutta-Fehlberg fourth-fifth order method with shooting technique. The effects of different controlling parameters, namely, Lewis number, Prandtl number, buoyancy ratio, thermophoresis, Brownian motion, magnetic field and Newtonian heating on the flow and heat transfer are investigated. The numerical results for the dimensionless axial velocity, temperature and nanoparticle volume fraction as well as the reduced Nusselt and Sherwood number have been presented graphically and discussed. It is found that the rate of heat and mass transfer increase as Newtonian heating parameter increases. The dimensionless velocity and temperature distributions increase with the increase of Newtonian heating parameter. The results of the reduced heat transfer rate is compared for convective heating boundary condition and found an excellent agreement.
    Matched MeSH terms: Electric Conductivity
  15. Modeling of the dissolution kinetics of arbutus wild berries-based tablets as evaluated by electric conductivity
    Tounsia Abbas-Aksil, Salem Benamara
    Sains Malaysiana, 2015;44:301-308.
    Lyophilized powder (LP) from Algerian arbutus wild berries (Arbutus unedo L.) was obtained. This present paper reports about the dissolution (releasing) properties of LP-based tablets, evaluated through the electric conductivity (EC) of distilled water which is employed as surrounding medium, at three different temperatures (291, 298 and 309 K). In addition to this, secondary physicochemical characteristics such as elementary analysis, color and compressibility were evaluated. Regarding the modeling of ionic transfer, among the three tested models, namely Peleg, Singh et al. and Singh and Kulshestha, the latter seems to be the most appropriate (R2 = 0.99), particularly in the case of compacted tablets under 2000 Pa. The temperature dependence of the dissolution process was also studied applying Arrhenius equation (R2>0.8) which allowed to deduce the activation energy, ranging from 18.7 to 21.4 kJ.mol-1 according to the model and compression force employed.
    Matched MeSH terms: Electric Conductivity
  16. Fulltext Gamma irradiation influence on mechanical, thermal and conductivity properties of hybrid carbon nanotubes/montmorillonite nanocomposites
    Tarawneh MA, Saraireh SA, Chen RS, Ahmad SH, Al-Tarawni MAM, Yu LJ
    Radiat Phys Chem Oxf Engl 1993, 2021 Feb;179:109168.
    PMID: 33100612 DOI: 10.1016/j.radphyschem.2020.109168
    A thermoplastic elastomer (TPE) based nanocomposite with the same weight ratio of hybrid nanofillers composed of carbon nanotubes (CNTs) and montmorillonite nanoclay (DK4) was prepared using a melt blending technique with an internal mixer. The TPE composite was blended from polylactic acid (PLA), liquid natural rubber (LNR) as a compatibilizer and natural rubber (NR) in a volume ratio of 70:10:20, respectively. The weight ratio of CNTs and DK4 was 2.5 wt%. The prepared samples were exposed to gamma radiation at range of 0-250 kGy. After exposure to gamma radiation, the mechanical, thermo-mechanical, thermal and electrical conductivity properties of the composites were significantly higher than unirradiated TPE composites as the irradiation doses increased up to 150 kGy. Transmission electron microscopy (TEM) micrographs revealed the good distribution and interaction between the nano-fillers and the matrix in the prepared TPE hybrid nanocomposites. In summary, the findings from this work definite that gamma irradiation might be a viable treatment to improve the properties of TPE nanocomposite for electronic packaging applications.
    Matched MeSH terms: Electric Conductivity
  17. Investigation of interpolymer complexation between Carbopol and various grades of polyvinylpyrrolidone and effects on adhesion strength and swelling properties
    Tan YT, Peh KK, Al-Hanba O
    J Pharm Pharm Sci, 2001 Jan-Apr;4(1):7-14.
    PMID: 11302785
    To investigate the interpolymer complexation between Carbopol 934P (CP) and various grades of polyvinylpyrrolidone (PVP) (K90, K32, C15, and VA/S-630).
    Matched MeSH terms: Electric Conductivity
  18. Effects of aeration rate on degradation process of oil palm empty fruit bunch with kinetic-dynamic modeling
    Talib AT, Mokhtar MN, Baharuddin AS, Sulaiman A
    Bioresour Technol, 2014 Oct;169:428-38.
    PMID: 25079208 DOI: 10.1016/j.biortech.2014.07.033
    The effect of different aeration rates on the organic matter (OM) degradation during the active phase of oil palm empty fruit bunch (EFB)-rabbit manure co-composting process under constant forced-aeration system has been studied. Four different aeration rates, 0.13 L min(-1) kg(DM)(-1),0.26 L min(-1) kg(DM)(-1),0.49 L min(-1) kg(DM)(-1) and 0.74 L min(-1) kg(DM)(-1) were applied. 0.26 L min(-1) kg(DM)(-1) provided enough oxygen level (10%) for the rest of composting period, showing 40.5% of OM reduction that is better than other aeration rates. A dynamic mathematical model describing OM degradation, based on the ratio between OM content and initial OM content with correction functions of moisture content, free air space, oxygen and temperature has been proposed.
    Matched MeSH terms: Electric Conductivity
  19. Fulltext Optical Properties and Conductivity of PVA-H3PO4 (Polyvinyl Alcohol-Phosphoric Acid) Film Blend Irradiated by γ-Rays
    Susilawati S, Prayogi S, Arif MF, Ismail NM, Bilad MR, Asy'ari M
    Polymers (Basel), 2021 Mar 28;13(7).
    PMID: 33800592 DOI: 10.3390/polym13071065
    This study assesses the optical properties and conductivity of PVA-H3PO4 (polyvinyl alcohol-phosphoric acid) polymer film blend irradiated by gamma (γ) rays. The PVA-H3PO4 polymer film blend was prepared by the solvent-casting method at H3PO4 concentrations of 75 v% and 85 v%, and then irradiated up to 25 kGy using γ-rays from the Cobalt-60 isotope source. The optical absorption spectrum was measured using an ultraviolet-visible spectrophotometer over a wavelength range of 200 to 700 nm. It was found that the absorption peaks are in three regions, namely two peaks in the ultraviolet region (310 and 350 nm) and one peak in the visible region (550 nm). The presence of an absorption peak after being exposed to hυ energy indicates a transition of electrons from HOMO to LUMO within the polymer chain. The study of optical absorption shows that the energy band gap (energy gap) depends on the radiation dose and the concentration of H3PO4 in the polymer film blend. The optical absorption, absorption edge, and energy gap decrease with increasing H3PO4 concentration and radiation dose. The interaction between PVA and H3PO4 blend led to an increase in the conductivity of the resulting polymer blend film.
    Matched MeSH terms: Electric Conductivity
  20. Fulltext Investigating the Correlation between Electrolyte Concentration and Electrochemical Properties of Ionogels
    Suen JW, Elumalai NK, Debnath S, Mubarak NM, Lim CI, Reddy Moola M, et al.
    Molecules, 2023 Jul 04;28(13).
    PMID: 37446854 DOI: 10.3390/molecules28135192
    Ionogels are hybrid materials comprising an ionic liquid confined within a polymer matrix. They have garnered significant interest due to their unique properties, such as high ionic conductivity, mechanical stability, and wide electrochemical stability. These properties make ionogels suitable for various applications, including energy storage devices, sensors, and solar cells. However, optimizing the electrochemical performance of ionogels remains a challenge, as the relationship between specific capacitance, ionic conductivity, and electrolyte solution concentration is yet to be fully understood. In this study, we investigate the impact of electrolyte solution concentration on the electrochemical properties of ionogels to identify the correlation for enhanced performance. Our findings demonstrate a clear relationship between the specific capacitance and ionic conductivity of ionogels, which depends on the availability of mobile ions. The reduced number of ions at low electrolyte solution concentrations leads to decreased ionic conductivity and specific capacitance due to the scarcity of a double layer, constraining charge storage capacity. However, at a 31 vol% electrolyte solution concentration, an ample quantity of ions becomes accessible, resulting in increased ionic conductivity and specific capacitance, reaching maximum values of 58 ± 1.48 μS/cm and 45.74 F/g, respectively. Furthermore, the synthesized ionogel demonstrates a wide electrochemical stability of 3.5 V, enabling diverse practical applications. This study provides valuable insights into determining the optimal electrolyte solution concentration for enhancing ionogel electrochemical performance for energy applications. It highlights the impact of ion pairs and aggregates on ion mobility within ionogels, subsequently affecting their resultant electrochemical properties.
    Matched MeSH terms: Electric Conductivity
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links