Advances in Chemical Engineering and Science

Published by Scientific Research Publishing
Online ISSN: 2160-0392
Publications
Complex plane impedance plots (a) −0.3 [V vs. SCE], (b) E corr [V vs. SCE] and (c) 0.1 [V vs. SCE] and Bode plots (d) −0.3 [V vs. SCE], (e) E corr [V vs. SCE] and (f) 0.1 [V vs. SCE], in a medium containing 3.5 wt% NaCl, 1 mmol•L −1 Na 2 S, in the absence and presence of HEDP inhibitor at concentrations of 20, 30, 50 and 100 mg•L −1 (where the line represents the fitting of the curves obtained in the data simulation).
Complex plane impedance plots (a) −0.3 [V vs. SCE], (b) E corr [V vs. SCE] and (c) 0.1 [V vs. SCE] and Bode plots (d) −0.3 [V vs. SCE], (e) E corr [V vs. SCE] and (f) 0.1 [V vs. SCE], in a medium containing 3.5 wt% NaCl, 1 mmol•L −1 Na 2 S, in the absence and presence of the HEDP inhibitor at a concentration of 50 mg•L −1 and the addition of 10, 20 and 30 mg•L −1 CaCl 2 (where the line represents the curve fitting obtained in the data simulation).
also shows Bode plots at −0.3 [V vs. SCE] (d), E corr [V vs. SCE] (e), and 0.1 [V vs. SCE] (f) in a medium containing chloride, sulfide, and HEDP inhibitor in the presence and absence of magnesium. It was shown that for all investigated concentrations a single peak was identified, demonstrating that the corrosive process of AISI 304 stainless steel in these conditions is influenced by the charge transfer process and capacitance of the electrical double layer [45]. As verified for the presence of Zn, the stabilization of the film on the AISI 304 stainless steel surface in the presence of Mg is confirmed by the phase angle increase from −71.9˚(9˚(−0.3 [V vs. SCE]-Figure 5(d)) to −78.3˚(3˚(0.1 [V vs. SCE]-Figure 5(f)), indicating an adsorption of the inhibitor molecule on the metal surface.
shows the influence of the addition of Ca, Zn, and Mg elements in a solution containing 50 mg•L −1 HEDP on the AISI 304 stainless steel surface after open circuit potential measurements. It is observed that in the absence of divalent cations, the deposition of NaCl crystals on the metal surface was verified and the corrosion product is justified by the presence of Fe and Cl in the EDS spectra (Figure S5 in the supplementary material) and the elemental mapping (Figure S6 in the supplementary material). Fe 2+ ions from the oxidation reaction (Equation 12) reacts with chloride ions (Cl − ) present in the medium and forms FeCl 2(s) as shown in equation 13. The formation of this solid in aqueous solution
Results obtained in the weight loss test.
Article
The novelty of this paper is the analysis in a medium containing sulfide ion due to the generation of this ion in petroleum industries, in the refining stage (the sulfide ion is also present on the produced water). The performance of 1-hydroxyethylidene-1,1-diphosphonic acid inhibitor (HEDP) was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy, and weight loss measurements in a dissolution of AISI 304 stainless steel immersed in a solution containing chloride and sulfide ions. The protection of the stainless was increased with the addition of divalent cations (Ca2+, Zn2+, and Mg2+). Potentiodynamic polarization studies have shown that the inhibitor alone has anodic protection, but the addition of Ca2+ (10 mg·L-1) favors the cathodic protection, and the addition of Zn2+ (20 mg·L-1) and Mg2+ (10 mg·L-1) mixed-type is observed. Electrochemical impedance spectroscopy was performed at three distinct potentials: -0.3 [V vs. SCE], Ecorr [V vs. SCE], and 0.1 [V vs. SCE]. This revealed that calcium is responsible for favoring the formation of the film and the other elements (zinc and magnesium) favor the stabilization of the protective film. Scanning electron microscopy analysis revealed that the addition of cations provided the adsorption of HEDP on the metal surface. Weight loss results showed that the presence of zinc in a solution containing HEDP favored greater inhibitor efficiency (Zn2+ ηm = 85.2% and for Mg2+ ηm = 70.4%)
 
Variation of the free enthalpy of formation at 298 K as a function of the silica content of bioactive glasses 20.15[(2.038 + x)SiO 2 -(1.457 − x)Na 2 O]-2.6-P 2 O 5 -26.95CaO.  
Variation of the index of bioactivity (RN) based on the free enthalpy of formation at 298 K bioactive glasses system 20.15[(2.038 + x)SiO 2 -(1.457 − x)Na 2 O]-2.6-P 2 O 5 -26.95CaO.  
Article
Bioactive glasses in the system SiO 2-Na 2 O-CaO-P 2 O 5 were prepared by the conventional melting process at a high temperature in an electric furnace. The densities of the glasses as well as their glass transition temperatures were measured experimentally. Also, the glasses were characterized by solution calorimetry at 298 K in an acidic solvent consisting of HF (6 M) and HNO 3 (4 M). A simulation of the bioactivity properties of these obtained glasses was carried out by thermodynamic calculations, with the purpose of understanding the in vitro results obtained.
 
Article
In this work, we recover cobalt from waste 18650-type lithiumion batteries by acid leaching. The cathode material is completely dissolved, after leaching waste batteries by using 10 mol/L industrial sulfuric acid at 70℃ for 1 h. The rate of cobalt leaching is nearly 100%. Removal of sodium carbonate, iron, aluminum and other impurities from the leaching solution was well performed by adjusting the pH to 2-3 with stirring vigorously. Finally, under the conditions of 55℃-60℃ of 240 A/m2 current density, electrodeposition current efficiency was 90.01%, the quality of the electrical output achieved cobalt 1A standard electrolytic cobalt, cobalt until greater than 90% yield. The process is easy and suitable for large-scale lithiumion batteries used in the recovery of valuable metals.
 
shows the spectra of Leonardite and Ba-HA. Absorption bands in the 3600-2800 cm −1 spectral region for Leonardite and Ba-HA were very broad; absorbance in this region was determined by the presence of-OH, NH and C-H groups [9]. In Leonardite, the bands at 2900 cm −1 and 2850 cm −1 (aliphatic C-H stretching vibration) appear more intense and clear. Absorption within the range from 2000 to 1500 cm −1 is characteristic for functional groups with double bonds for Leonardite. Usually these are C=O and C=C. Polysaccharide absorption bands can be observed, mostly around 1040 cm −1. The spectrum presents intense bands around 1000 and 500 cm −1 corresponding to mineral materials. The band at about 1470 cm −1 (COO-) is more pronounced in Ba-HA.
FTIR spectra of Leonardite and Ba-HA.
Pilot plant trial conditions. 
Surface area of the samples calcinated at different conditions. 
Article
On an example of spontaneous changes 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one at room temperature, a new example of condensations in a solid station is opened. The single crystal of 2-(3’, 5'-di-tert-butyl-4'-hydroxy-phenyl)-ethyloxy-p-cresole is produced as result of a structure transformation 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one in a solid phase at room temperature except a single crystal at transformation 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one a new substance is formed too. Spectrums 1Н and 13С NMR differ from similar spectrums of initial compound and the single crystal. New substance represents an admixture of isomeric compounds, capable reversible to be transformed in initial 5,7-di-tert-butylspiro(2,5) octa-4,7-diene-6-one and 2-(3’, 5'-di-tert-butyl-4'-hydroxyphenyl)-ethyloxy-p-cresole.
 
Article
Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55℃ - 60℃, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa is formed. The constitution is based on dates of spectrums 1Н and 13С NMR. At 95℃ - 97℃, mixtures of 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa and of 6,8-di-tert-butyl-3-(N-acetylamine)spiro(4,5)deca-1-oxa-5,8-dien-2,7-dione are produced. Structures are calculated by the method of Hartrii-Foka. Values of enthalpies and of entropies allow to assume dynamic isomerism.
 
CGTase activity (circle) and specific activity of CGTase (diamond) against time enzyme production with Bacillus firmus strain 37 immobilized on bone charcoal.
CGTase activity (circle), pH (triangle) and total reducing sugars concentration (square) versus time for enzyme production with immobilized Bacillus firmus strain 37 on bone charcoal.
CGTase activity (circle) and specific activity (diamond) plotted against time in 48 h five sequential batches of Bacillus firmus strain 37 immobilized on bone charcoal.
CGTase activity (circle), pH (triangle) and concentration of total reducing sugars (square) versus time for enzyme production with Bacillus firmus strain 37 immobilized on bone charcoal in five repeated batches of 48 h intervals.
Studies on CGTase production using free microorganism in the culture medium.
Article
The present study aimed to study the batch production of CGTase (cyclomaltodextrin-glucanotransferase) with Bacillus firmus strain 37 free and immobilized in bovine bone charcoal in batch mode and in a fluidized bed batch reactor, respectively. The bovine bone charcoal is an innovative support material for the immobilization of microorganisms’ producers of enzymes and the use of this microbial support allows its reuse to a significant cost reduction of the process. The batch fermentation with free cells was investigated for 96 h and reached a CGTase activity equal to 0.77 U/mL. When the microorganism was immobilized on bovine bone charcoal (7 g) and cultivated in fluidized bed batch reactor with air supplementation (1 volume of air/volume of medium * minute), the same activity could be achieved in 24 h. The results of enzymatic activity achieved show the potential of CGTase production in a short time with Bacillus firmus strain 37 immobilized in bovine bone charcoal matrix and using air supplementation in the production medium.
 
Article
A new difunctional monomer N,N'-[bis(4,4'-hydroxypropyl methacrylate phenyl ester) pyromelli-timide] (BHPMEPM), was synthesized by the reaction of the bis(4-carboxyphenyl)-N,N'-pyromelli-timide acid (diacid-diimide), and two molar equivalents of glycidylmethacrylate (GMA). The reaction was carried out by microwave radiation. The presence of difunctional groups, double bond groups, makes the monomer a potential material for obtaining thermosetting product. The curing and thermal stability of the crosslinked products were studied by differential scanning calorime-try (DSC) and thermal gravimetric analysis (TGA) techniques. The difunctional monomer and its thermoset polymer were characterized by FT-IR, 1 H-FT-NMR and CHN elemental analysis.
 
NH3-TPD of β/Al-MCM-41 and Al-MCM-41. (a) β/Al-MCM-41, (b) Al-MCM-41.  
Py-FTIR of β/Al-MCM-41 and Al-MCM-41. (a) β/Al-MCM-41, (b) Al-MCM-41.  
Results on reuse of the catalyst.  
XRD patterns of fresh and reused β/Al-MCM-41. (a) fresh β/Al-MCM-41, (b) reused β/Al-MCM-41.  
Arrhenius plot of reaction rate constant of esteri- fication.  
Article
β/Al-MCM-41 molecular sieve was synthesized and used to catalyze the esterification of oleic acid with short chain alcohols such as methanol, ethanol, isopropanol and isobutanol to obtain biodiesel. The results indicated that β/Al-MCM-41 exhibited the excellent catalytic activity and stability, which was obviously superior to traditional Al-MCM-41. The relationship between acidity and catalytic activity was in detail examined by NH3-TPD and Py-FTIR. Moreover, the kinetics of esterification of oleic acid with methanol showed that the average reaction order n was 1.97 and that activation energy was 50.01 kJ/mol.
 
Article
The CO2 separation from natural gas, syngas or flue gas represents an important industrial field of applications. An economic and energy-efficient CO2 separation from these gas streams is a prerequisite for sustainable industry contributions to the megatrends resource efficiency and globalization of technologies. One way of reducing operational expenditure for these separation processes is the development of better performing CO2 absorbents. Although a number of absorbents for the separation of CO2 from process gas streams exist, the need for the development of CO2 absorbents with an improved absorption performance, less corrosion and foaming, no nitrosamine formation, lower energy requirement and therefore less operational expenditure remains. Recent industrial activities have led to the development of novel high-performance CO2 scrubbing agents that can be employed in numerous industrial processes such as natural gas treatment, purification of syngas and the scrubbing of flue gas. The objective of this paper is to introduce these new high-performance scrubbing agents and to compare their performance with other state-of-the-art absorbents. It turned out, that the evaluated absorbents offer high cyclic capacities in the range of 2.4 to 2.6 mol CO2/kg absorbent and low absorption enthalpies (–30 kJ/mol) allowing for distinctive savings in the regeneration energy of the absorbent. Calculations with the modified Kremser model resulted in a reduction of the specific reboiler heat duty of 55%. Furthermore, the absorbents are less corrosive than standard amines as indicated by the measured corrosion rates of 0.21 mm/y versus 1.18 mm/y for a piperazine/methyldiethanolamine mixture. Based on new experimental results it is shown how substantial savings in operational and capital expenditure can be realized due to favorable absorbent properties. The novel high-performance CO2 system solutions meet recent industrial absorbent requirements and allow for more efficient or new CO2 separation processes.
 
Article
Application of methanol solvent for physical absorption of CO2 and H2S from CO2/H2S/CH4 mixture in gas–liquid hollow fiber membrane gas absorber (HFMGA) was investigated. A computational mass transfer (CMT) model for simulation of HFMGA in the case of simultaneous separation of CO2 and H2S was developed. The membrane gas absorber model explicitly calculates for the rates of mass transfer through the membrane and components concentration profiles. Due to the lack of experimental data in the literature, the model was validated using available individual components’ water absorption data. The numerical predictions were in good agreement with the experimental data. The effects of operating conditions such as liquid velocity, gas velocity, temperature and pressure were analyzed. It is shown that methanol solvent can successfully be used for CO2 and H2S removal in membrane gas absorber. Also it is found that the concentration distribution of CO2 and H2S in the gas phase along the fiber length obeys plug flow model whereas in the methanol absorbent deeply affected by the interface concentration, absorbent velocity and diffusivity. In addition, it is shown that application of membrane gas absorber using methanol absorbents for H2S removal and at higher flow rate is more efficient. Moreover, at operating pressures above 10 atm even at low absorbent rate, H2S concentration depletion is relatively complete while at 1 atm this value is about 30%. This means that removal efficiency decreases with an increase in temperature and it is more important especially for H2S.
 
Article
The negative effects of hydrogen embrittlement on metallic systems have been investigated through determination of the mechanical properties of two metallic systems that were exposed to hydrogen. An assessment of the effects of hydrogen absorption/desorption cycling on the tensile strength, ductility, and microhardness of pure palladium and the alloy palladium-silver (25 weight% silver) has been undertaken. The variables that are the focus of the study are the amount of hydrogen absorbed by the metal, deuterium isotope effect, number of hydrogen absorption/desorption cycles, and the hydrogen exposure temperature. Under all conditions studied, the mechanical properties of pure palladium were significantly altered as a result of hydrogen exposure, with significant hydrogen embrittlement occurring. In contrast, the mechanical properties of the palladium-silver alloy showed little alteration as a result of hydrogen exposure, including virtually no occurrence of hydrogen embrittlement.
 
Article
Chemical flooding is one of the most efficient methods for Enhanced Oil Re-covery (EOR). This study demonstrates the efficiency of mixing different concentrations of Ionic Liquid (IL), 1-Ethyl-3-Methyl-Imidazolium Acetate ([EMIM][Ac]), with Weyburn brine toimprove a medium oil recovery, Weyburn oil, from an unconsolidated sand pack sample at room conditions. Effects of Slug Size (SS), IL + brine slug initiation time, and combining IL with alkali on the Recovery Factor (RF) were investigated. This study showed that the optimum concentration of ([EMIM][AC]) was 1000 ppm and the most efficient injection time of the chemical slug was at the beginning of the flooding procedure (as secondary flooding mode). In addition, it was proved that the potential of injecting a slug of IL + brine is much better than that of introducing a slug of alkali + brine. Besides, the combination of IL and alkali (AIL) resulted in better RF than injecting either of them alone. Finally, the Surface Tension (SFT), pH, wettability alteration, and viscosity of the displac-ing phases were measured.
 
Existing explicit friction factor models.
Relative error distribution for this study, Zigrang and Sylvester [14], Serghides [15] and Buzzelli [16] models when compared with the implicit Colebrook equation.
Explicit models ordered by maximum relative error.
Computational efficiencies of the proposed and existing explicit models.
Article
The implicit Colebrook equation has been the standard for estimating pipe friction factor in a fully developed turbulent regime. Several alternative explicit models to the Colebrook equation have been proposed. To date, most of the accurate explicit models have been those with three logarithmic functions, but they require more computational time than the Colebrook equation. In this study, a new explicit non-linear regression model which has only two logarithmic functions is developed. The new model, when compared with the existing extremely accurate models, gives rise to the least average and maximum relative errors of 0.0025% and 0.0664%, respectively. Moreover, it requires far less computational time than the Colebrook equation. It is therefore concluded that the new explicit model provides a good trade-off between accuracy and relative computational efficiency for pipe friction factor estimation in the fully developed turbulent flow regime.
 
Chemical structures of the dimeric cationic compounds (3a-e) under study.
96 h-EC50 obtained with C. vulgaris and 24 and 48 h-EC50 obtained with D. magna after exposure to TCMTB and gemini compound 3e. 
Article
A series of N-acetylated cationic gemini surfactants (3a-e) having dimeric structures derived from tertiary amines were synthesized. Their antifungal potency and surface properties were determined. It also studied the acute toxicity of the molecule with the best performance and the best water so-lubility (3e) through Chlorella vulgaris and Daphnia magna bioassays. The results were compared to those obtained for a commercially available reference compound 2-(thiocyanomethylthio) benzothiazole (TCMTB). Parameters such as surface tension (γ CMC), critical micelle concentration (CMC), surface excess concentration (Γ), and area per molecule (A) were determined. The resulting values indicated that the five gemini surfactants are characterized by good surface-active and self-aggregation properties. All surfactants were tested to evaluate their antifungal activity. Six fungal strains were used to conduct the study. The minimum inhibitory concentration (MIC) value was measured by the fungal growth inhibition. The results of the MICs were compared with two commercially available reference compounds (Fluconazole and TCMTB). The least active molecule was 3e, but 3b and 3d were found to be the most potent compounds with a similar activity for all strains. Candida albicans was the most sensitive one. In contrast, Aspergillus niger was resistant. Ecotoxicity of gemini 3e was assessed: the commercial formulation (TCMTB) was between three and four orders of magnitude more toxic than the gemini one for the biological species tested.
 
Article
The 2101, 2205 and 2507 are duplex stainless steels. They have two phases: austenite and ferrite. The metallurgical characterization was performed by means of Scanning Electron Microscopy (SEM) with EDX and X-ray diffractometry (XRD). The corrosion behaviour was evaluated by potentiodynamic tests. The corrosion tests were conducted with the aid of potentiostat. The SEM and XRD revealed phases of austenite and ferrite without any intermetallic phase. The elemental analysis of the phases showed that the elements partitioned more into the phases that they promoted. The corrosion resistance of 2507 was higher than 2205 and 2101 as it may be seen on the polarization curves. Comparing the two media, the following relation to their corrosion resistance: 2507 > 2205 > 2101 was established.
 
Concentration (in mg/g) in extracted and methylated food items. 
Article
The research is designed to study the relationship of intake of fatty acids through fast food items, consumption trends and related health issues. Fried food products most commonly consumed at restaurants were selected. Food outlets of both branded and non-branded vendors were included in the study for comparison. Total fat content, Fatty acids and Fatty Acid Methyl Esters (FAME's) in food samples were determined experimentally using titrimetric and spectropho-tometric methods. Fatty acids of Stearic, Oleic and Myristic were extracted from each food sample using petroleum ether as extracting solvent, followed by conversion to FAME's by treating the filtrate with methylamine, ethanol and sulphuric acid. A survey analysis using the questionnaire as a tool was also conducted. The results showed variable concentration in each sample. Total fat content was highest in French fries, followed by fish and chicken. Among the fatty acids, Stearic acid was found highest in concentration than other two fatty acids. The study concluded that the level of saturated fatty acids was 0.4 g (7.6%), which was securely under the allowable limit of daily value (on a 2000 calorie diet) of 3 g (15%).
 
Article
Antioxidant activity of interaction products of the studied compounds with tret-Butyl hydroperoxide is studied. New, more active acceptors of free radicals are formed in the process of oxidative transformations of initial compounds. It is investigated that the products have high inhibiting properties. The parameter fk, characterizing inhibitory effect of an inhibitor is studied.
 
Article
The use of the four new synthesized polyurethane acrylate binders in the pigment print paste for screen printing cotton and polyester fabrics and pigment fixation through the polymerization process of the binder by using the thermofixation technique as well as the UV curing technique was studied. The effect of changing time and temperature of thermofixa-tion, and the time of UV curing on the color strength, and prints fastness properties were also studied. The results showed that, the newly synthesized polyurethane acrylate binders could be successfully used for pigment fixation on cotton and polyester using the two fixation techniques and in general their prints possessed better color strength values as compared to those obtained upon using the selected commercial binders.
 
The apparent viscosity of synthesized PUA polymers. 
Article
Some new an aqueous polyurethane acrylate (waterborne binder) based on polyethylene glycol with different M. wt. mixed with polyol were carried out. Seven different polyurethane acrylate co-polymers were prepared aiming at substituting the two hydroxyl groups of polyethylene glycol (6000, 12,000 and 20,000 g/mol) and two primary hydroxyl groups of polyol through their reaction with corresponding calculated amounts of either isophorone diisoyanate or toluene diisocyanate and caped the remaining isocyanate group with either hydroxy ethyl acrylate or hydroxy propyl methacrylate to get on the polyurethane acrylate polymers [PUA]. From DSC measurement the result of Tg of synthesized PUA are in range from -8.78℃ to 36.4℃. So they can classify as soft binders. The infrared spectra, rheological properties, viscosity measurement, the weight average molecular weight, of the synthesize binders were investigated.
 
Article
The ability of some nanostructured materials to perform as effective heterogeneous catalysts is potentially hindered by the failure of the liquid reactant to effectively wet the solid catalyst surface. In this work, two different chemical reactions, each involving a change of phase from liquid to gas on a solid catalyst surface, are investigated. The first reaction is the catalyzed decomposition of a H2O2 monopropellant within a micro-chemical reactor chamber, decorated with RuO2 nanorods (NRs). The second reaction involves the electrolysis of dilute aqueous solutions of H2SO4 performed with the cathode electrode coated with different densities and sizes of RuO2 NRs. In the catalyzed H2O2 decomposition, the reaction rate is observed to decrease with increasing catalyst surface density because of a failure of the liquid to wet on the catalyst surface. In the electrolysis experiment, however, the reaction rate increased in proportion to the surface density of RuO2 NRs. In this case, the electrical bias applied to drive the electrolysis reaction also causes an electrostatic force of attraction between the fluid and the NR coated surface, and thus assures effective wetting.
 
Article
Snail shell waste (Helix pomatia) has been evaluated as raw material for the preparation of activated carbon using ZnCl2 and CaCl2 with the temperature ranging from 500°C to 800°C. The activated carbon prepared was characterized, showing effect of temperature on ash content, pore volume and porosity. The adsorption isotherm for methylene blue was carried out on the activated carbon in a batch study. The adsorbent exhibited excellent adsorption for methylene blue. The experimental data were used for both Langmuir and Freundlich models. The adsorption coefficients of Langmuir isotherm were found to be 0.996 and 0.957 for CaCl2 and ZnCl2 while 0.969 and 0.962 were obtained for the Freundlich isotherm respectively. The value of RL was found to be 0.75 and 0.38 for samples CC and ZZ respectively, which is an indication that activated carbon impregnated with CaCl2 and ZnCl2 is favourable for adsorption of methylene blue under the conditions used in this study.
 
N 2 adsorption isotherm at 77 K of CAK, CAN and CAC carbons.  
Electrostatic (acid-base) properties of activated carbons.
FTIR spectra of CAK, CAN and CAC carbons.  
Capacitance of activated carbons at different voltage sweep rates.
Dependence of capacitance (at voltage sweep rate, 5 mV/s) on specific surface area of CAK, CAN and CAC carbons.
Article
Activated carbons (ACs) were prepared from a lignocellulosic-based waste material by a chemical impregnation method using KOH, NaOH or CaCl2 as the activating agent. These ACs were characterized by different techniques such as N2 adsorption, FTIR, XRD and SEM. Electrostatic properties viz. pH and pHpzc of AC suspensions in aqueous media were measured. The concentration of surface oxygenated functional groups of the ACs was estimated following the Boehm titration method. Cyclic voltammetry was conducted in H2SO4 after fabricating two-electrode capacitor cells of the ACs. The correlation of AC surface chemistry and morphology with electrochemical performance (capacitance) of powdered electrodes is analyzed and discussed.
 
Top-cited authors
Preeti Verma
  • Indian Institute of Technology Kanpur
Rashmi Sanghi
  • PEC University of Technology
Zeinab abou-gamra
  • Ain Shams University
Ibtissem Bouftira
  • University of Monastir
Chedly Abdelly
  • Centre de Biotechnologie, Technopole Borj Cédria