Indian Journal of Chemical Technology
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VOLUME
17
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NUMBER 6
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NOVEMBER 2010
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CODEN:ICHTEU
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ISSN:0971-457X
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Papers |
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Evaluation of porous nickel
hydroxide electrode for the oxidation of aliphatic |
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and aromatic primary alcohols |
411 |
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Corrosion behaviour of
sol-gel Al2O3 coated Al-Si alloy in 3.5%
NaCl solution |
419 |
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Inhibition of mild steel
corrosion in |
425 |
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Absorption of carbon
dioxide into a mixed aqueous solution of diethanolamine and piperazine |
431 |
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Solvent extraction and
separation of Mo(VI) and W(VI) from hydrochloric acid solutions using cyanex-923 as extractant |
436 |
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Extraction of acetic acid
from aqueous solutions by emulsion type liquid membranes using Alamine 300 as a carrier |
441 |
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A comparative study on
basicity based on supported K-salt catalysts for isomerization of 1-methoxy- 4-(2-propene-1-yl) benzene |
446 |
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Baldev Singh, Jyoti Patial, Parveen Sharma, Suresh
Chandra, Sudip Maity &
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Oxidation of phenol using
LaMnO3 perovskite, TiO2, H2O2 and
UV radiation |
451 |
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Comminution behaviour of
microwave heated two sulphide copper ores |
455 |
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Conductometric studies on
salvation behaviour of citric acid in water + methanol and water + ethanol mixtures at different temperatures |
462 |
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Note |
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Determination of boron in
zirconium-niobium alloys by spectrophotometry |
468 |
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Acknowledgement to Reviewers |
471 |
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Annual Author Index |
473 |
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Annual Keyword Index |
475 |
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Guidelines for
Authors
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479
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Indian Journal of Chemical Technology
Vol.17, November 2010, pp. 411-418
Evaluation of porous nickel hydroxide electrode for the oxidation of aliphatic and aromatic primary alcohols
T Vijayabarathi, K Vijayarani & M Noel
The positive plate of Ni-Cd battery was evaluated as Ni(OH)2/NiOOH electrode for the oxidation of six aromatic and five aliphatic alcohols. In addition to galvanostatic preparative electrolysis, cyclic voltammetric experiments were also carried out. The anode material after electrolysis was evaluated using SEM and XRD. Except in the case of chlorine substituted aromatic alcohols the nickel hydroxide electrode showed excellent stability even after the reuse for nearly 10-15 times. In 0.1 M KOH containing 67% tertiary butanol + 33% water as electrolyte, aromatic alcohols gave predominantly aldehyde in good yield. In alkaline solutions without the co-solvent tertiary butanol aromatic alcohols were oxidized to their corresponding carboxylic acids. Short chain aliphatic alcohol (C5) gave reasonable yield of carboxylic acid. Long chain alcohols showed limited solubility in alkaline medium with and without co-solvent tertiary butanol and the yields of carboxylic acids were also poor.
Keywords: Alcohols, Catalytic activity, Porous nickel hydroxide electrode, Oxidation, Voltammetry
Indian
Journal of Chemical Technology
Vol.
17, November 2010, pp. 419-424
Corrosion behaviour of sol-gel Al2O3 coated Al-Si alloy in 3.5% NaCl solution
I B Singh, M Singh,
Alumina sol was synthesised and coated on Al-Si alloy. The coated substrates were heated at 300ºC for sintering and precursor removal purposes. The cross sectional examination of the coated specimens in SEM showed the presence of around 7 μm thick non porous and compact coating. XRD analysis confirmed the presence of αAl2O3 in the coated layer. The corrosion characteristics of the coating were evaluated in 3.5% NaCl solution by electrochemical measurements. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) analysis indicated that the coated substrate possesses an order of magnitude higher corrosion resistance as compared to uncoated substrate. EIS study has also indicated a significant decrease in diffusion phenomena of chloride ions through the coating/metal interfaces. The effect of heat treatment of Al-Si alloy on its corrosion properties has also been investigated.
Keywords: Al-Si alloy, Composite, Alumina coating, Sol-gel process, Corrosion
Indian Journal of Chemical Technology
Vol. 17, November 2010, pp. 425-430
Inhibition of mild steel corrosion in 1 M hydrochloric acid using (E)-4-(2-chlorobenzylideneamino)-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one (CBMTDT)
Bincy Joseph, Sam John, K K Aravindakshan & Abraham Joseph
The use of nitrogen and sulphur donor organic
inhibitors in acid solutions is a common method for the protection of metals
from corrosion. The present work is the study of the corrosion inhibition
efficiency of
(E)-4-(2-chlorobenzylideneamino)-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one
(CBMTDT) towards mild steel in 1 M HCl. The work strategy includes the
conventional weight loss method, potentiodynamic polarization studies (Tafel),
linear polarization studies (LPR), electrochemical impedance spectroscopy
(EIS), adsorption studies and quantum chemical calculations. Results showed
that the corrosion rate decreases and inhibition efficiency increases with
inhibitor concentration. The results of polarization studies reveal that the
additive acts as a mixed type inhibitor. The surface adsorption of the
inhibitor molecules decreases the double layer capacitance and increases the
polarization resistance. The adsorption process is spontaneous and follows
Langmuir adsorption isotherm model. The optimized structure of the inhibitor,
energies of LUMO, HOMO and other physical parameters are calculated by
computational quantum chemical methods.
Keywords: Corrosion, Mild steel, Electrochemical impedence, Potentiodynamic polarization, CBMTDT
Indian Journal of Chemical Technology
Vol.
17, November 2010, pp. 431-435
Absorption of carbon dioxide into a mixed aqueous solution of diethanolamine and piperazine
The CO2 loading in aqueous mixtures of diethanolamine (DEA) and piperazine(PZ), from a mixture of CO2 and N2, has been measured for total amine concentrations and mole ratios of PZ to total amine ranging from 2.0 to 3.0 M and 0.01 to 0.20, respectively, at 313.14 K and 15.199 kPa CO2 partial pressure. Measurements were made by a saturation method using a laboratory scale bubble column. The results of CO2 loading are expressed as XCO2 (mole CO2 /mole of total amine) for all experimental runs. A model is given to predict the CO2 loading in aqueous mixture of DEA and PZ. The model predictions have been in good agreement with the experimental data of CO2 loading in aqueous mixture of DEA and PZ with the average deviation of 8.67.
Keywords: DEA, PZ, CO2 Loading, Total amine,
Bubble column
Indian Journal of Chemical Technology
Vol. 17, November 2010, pp. 436-440
Solvent extraction and separation of Mo(VI) and W(VI) from hydrochloric acid solutions using cyanex-923 as extractant
R G Talla, S U Gaikwad & S D Pawar
A systematic study of solvent extraction of molybdenum(VI) and tungsten(VI) from hydrochloric acid media using neutral phosphine oxide extractant, cyanex-923 in toluene has been performed. These metal ions are quantitatively extracted with cyanex-923 in toluene in the acidic range 5-7 M, and from the organic phase they are stripped with 1.0 M NaOH. The effect of pH, equilibrium period, diluents, diverse ions and stripping agent on the extraction of Mo(VI) and W(VI) has been studied. The extraction reactions proceed by solvation and the probable extracted species in the organic phase were MoO2Cl2.2Cyanex-923 and WO2Cl2.2Cyanex-923. Based on these results a sequential procedure for their separation from each other has been developed.
Keywords: Solvent extraction, Molybdenum(VI), Tungsten(VI), Cyanex-923, Stripping,
Separation
Indian Journal of Chemical Technology
Vol. 17, November 2010, pp. 441-445
Extraction of acetic acid from aqueous solutions by emulsion type liquid membranes using Alamine 300 as a carrier
Aynur Manzak & Melek
Sonmezoglu
The
extraction of acetic acid from aqueous solutions by an emulsion type liquid
membrane process was investigated, using Alamine 300 as carrier, Span 80 as
surfactant, and Na2CO3 solution as stripping agent. A
number of significant parameters viz.
mixing speed, surfactant concentration, diluent type, concentration of the
carrier Alamine 300, concentration of stripping agent, pH and concentration of
feed solution were investigated. Acetic acid was successfully extracted and
concentrated from aqueous solutions. Approximately 86% extraction of acetic
acid was achieved within 10 min in a stirred vessel.
Keywords: Acetic acid extraction, Alamine 300, Emulsion
liquid membrane, Surfactant, Diluent
Indian Journal of Chemical Technology
Vol.17, November 2010, pp. 446-450
A comparative study on basicity based on supported K-salt catalyst for isomerization of 1-methoxy-4-(2-propene-1-yl) benzene
Baldev Singh, Jyoti Patial, Parveen Sharma,
Suresh Chandra, Sudip Maity &
A comparative study on basicity of supported K-salt catalysts has been carried out for the preparation of trans-anethole [1-methoxy-4-(1-propen-1-yl) benzene]. It is observed that strong basic sites facilitated 99% conversion of methyl chavicol [1-methoxy-4-(2-propen-1-yl) benzene] with 89% selectivity of trans-anethole. Activation energy for isomerization of methyl chavicol was found to be in the range of 5.65 –8.67 kJ/mol using 25% K2CO3 loaded on alumina. The catalysts were characterized by CO2-TPD and BET surface area.
Keywords: Methyl chavicol, Trans-anethole, Basicity, Isomerization
Indian Journal of Chemical Technology
Vol. 17, November 2010, pp. 451-454
Oxidation of phenol using LaMnO3 perovskite, TiO2, H2O2 and UV radiation
Chandrakant Singh & Meeta Rakesh
LaMnO3
perovskite has been used for the treatment of aqueous solution of phenol using
stoichiometric amount of H2O2 and combination of TiO2
and UV radiation. The oxidation of phenol was studied with [UV radiation];
[H2O2 and UV]; [TiO2 and UV]; [LaMnO3
and UV]; [TiO2, H2O2 and UV]; [LaMnO3,
H2O2 and UV]; to establish the effectiveness of different
systems when compared with perovskite catalyst. Results show that the phenol
degradation efficiencies decreased in the following order [LaMnO3, H2O2
and UV] > [TiO2, H2O2 and UV] > [LaMnO3
and UV] > [TiO2 and UV]> [H2O2 and UV ]
> [UV]. UV-VIS spectra result of phenol degradation shows that as the
concentration of catalyst increases, its activity increases. The optimum
concentration of catalyst was 0.60 g/L for 100 ppm phenol solution. Perovskite
catalyst after reaction is completely regenerated by calcinations at
Keywords: Perovskite, Phenol, Hydrogen peroxide, Photochemical
reactor, AOPs
Indian Journal of Chemical Technology
Vol. 17, November 2010, pp. 455-461
Comminution behaviour of microwave heated two sulphide copper ores
Erol Kaya
The effect of microwave irradiation on the comminution of two sulphide copper ores with different mineralogy were investigated to enhance the milling processes. Each ore was subjected to microwave radiation for varying time periods to determine their heating profiles. Changes in breakage characteristics with the microwave exposure time were quantified by sieving breakage, standard Bond work index grindability and single particle drop weight comminution tests. The results of the sieving breakage tests with the untreated and microwaved samples indicated significant improvements in the size reduction due to microwave energy induced macro fracturing. Differing ore mineralogy has been shown to affect the effectiveness of microwave assisted size reduction. The results of the standard Bond work index grindability tests performed with both the microwave treated copper ores, on the other hand, suggested no significant improvements in grindability. The single particle fracture experiments performed with an Ultrafast Load Cell (UFLC) indicated similar results of no significant improvements in the fracture energies of the microwave treated ore samples.
Keywords: Microwave irradiation, Comminution, Copper ore
Indian Journal of Chemical
Technology
Vol.17, November 2010, pp. 462-467
Conductometric studies on solvation behaviour of citric acid in water + methanol and water + ethanol mixtures at different temperatures
J Ishwara Bhat & M
The paper reports the study on the effect of solvation of the species of citric acid in water + methanol and water + ethanol mixtures (v/v) on its conductivity behaviour as a function of temperature. The specific conductance was measured in the temperature range 283-313 K and the evaluated equivalent conductance was analyzed by Kraus-Bray and Shedlovsky models of conductivity. Limiting molar conductance (λ0m), dissociation constant (KC) and association constant (Ka) were evaluated for all solvent compositions. The limiting molar conductance was found to decrease with the increase in amount of co-solvent to water. Kc increased with increase in temperature till 60% methanol and 40% ethanol with a later decrease. Fuoss Accascina equation was applied and it was proved that the formation of ion pairs and scanty amount of ion triplets takes place in the system. Walden product, corrected Stokes radius (ri), thermodynamic parameters and solvation number also have been evaluated. Born relation of solvation was verified. These data were used to study the nature of ion-solvent and solvent-solvent interactions existing in the system under prevailing conditions.
Keywords: Solvation behaviour, Specific conductance, Citric acid
Indian Journal of Chemical Technology
Vol. 17, November 2010, pp. 468-470
Determination of
boron in zirconium-niobium alloys by spectrophotometry
P S
Ramanjaneyulu, Y
Boron doped zirconium-niobium
alloy rods are used as neutron reactivity control rods in advanced nuclear
reactors. Accurate knowledge about the boron content in this alloy is an
essential requirement prior to its usage in nuclear reactors. In view of the
refractory nature of the alloy, boron determination in these type of matrices
is a challenging task. Also due to non-availability of matrix matched reference
materials, direct solid analysis cannot be resorted to. Quantitative
dissolution of the matrix without losing any boron followed by its
determination is the only alternative. In the present work, Zr-Nb sample was
dissolved in (NH4)2SO4 and H2SO4
taking care to prevent the loss of boron. Boron was selectively separated
employing batch extraction with 10% 2-ethyl hexane 1,3 diol in chloroform and
determined spectrophotometrically as B-Curcumin complex. Absorbance was
measured at 550 nm. The precision and accuracy of the method is 3%. The
absolute detection limit of the method is 12 ng. The method has been evaluated
by standard addition method and validated by ICP-AES technique.
Keywords: Zr-Nb alloy,
Boron, Spectrophotometry, Curcumin