Indian Journal of Chemical Technology

Volume 9            Number 5            September 2002

 

CODEN:ICHTEU 9(5) 379-470                                                               ISSN: 0971-457X

                                                                                                                                               

 

CONTENTS

 


Research Articles

 

Synthesis of crosslinked methacrylic acid-co-ethyleneglycol dimethacrylate polymers for the removal of copper and nickel from water

385

  H Hari Prasad, Kirit M Popat & Pritpal Singh Anand

 

 

Preparation and performance of new base fuel antioxidant based on hindered phenol and heterocyclic amine

 

393

  Jigar Desai, A N Misra & K B Nair

 

 

 

Kinetic and thermodynamic studies on adsorption of fluoride by dolomite

397

  G Karthikeyan, Anitha Pius & G Alagumuthu

 

 

 

The thermodynamics of systems at negative absolute temperatures

402

  Jaime Wisniak

 

 

 

Effect of temperature on pitting corrosion of 316 SS in concentrated phosphoric acid containing hydrochloric acid

 

407

  M M Singh, Rita Khare & A K Mukherjee

 

 

 

Pb3BrF5: A lead halo composite as catalyst for allylation reactions

411

  N K Kala Raj, C S Sajanikumari, I R Unni, S B Halligudi & C Gopinathan

 

 

 

Process monitoring of Dibenz-[b,f]-1,4-oxazepine (CR) by gas chromatographic method

 

415

  Bidhan Chandra Bag & M P Kaushik

 

 

 

Synthesis and analytical application of lead selective thorium iodate cation exchanger

420

  M Jitha Kunhikrishanan & C Janardanan

 

 

 

Solvent extraction separation of palladium(II) with 2-oxo-4’-hydroxyphenyl-acetaldehyde oxime

424

  Shilpa S Utekar, S B Jadhav & S P Malve

 

 

 

Sensitive spectrophotometric method for the determination of pefloxacin

428

  K Basavaiah & H C Prameela

 

 

 

Chromotographic behviour of some synthetic dyes on unconventional layers

432

  Aditya K Misra, Pankaj S Saxena & Upasana Gupta

 

 

 

Determination of the limiting current density through potential step measurements

438

  R Fuchs-Godec, A Petek & V Dolecek

 

 

Contd.

 

Spray drying of beet root juice using different carriers

442

  V K Koul, M P Jain, Suman Koul, V K Sharma, C L Tikoo & S M Jain

 

 

 

Ferroconvection in an anisotropic packed porous medium

446

  G Vaidyanathan, R sekar & A Ramanathan

 

 

 

Educator

 

The history of chlorine- From discovery to commodity

450

  Jaime Wisniak

 

 

 

Announcement

464

 

 

Chem-Tech Scan

465

 

 

 

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 385-392

 

Synthesis of crosslinked methacrylic acid-co-ethyleneglycol dimethacrylate polymers for the removal of copper and nickel from water

 

H Hari Prasad, Kirit M Popat & Pritpal Singh Anand*

 

Crosslinked copolymers based on methacrylic acid and ethyleneglycol dimethacrylate were prepared by suspension polymerization and investigated for their ability to remove copper and nickel at trace level from heavy metal polluted water. The copolymers were characterized for physico-chemical properties like surface area, porosity and scientific weight capacity. The Langmuir and Freundlich adsorption isotherms were used to represent the experimental data. Saphn-Schlunder and Morris-Webber models applied to determine the external and intraparticle diffusion coefficients. The absorption process follows first order kinetics and the specific rate constant Kr was obtained by the application of Lagergan equation. Concentration ratios of 1:60 and 1:30 have been achieved for nickel and copper respectively under dynamic conditions.

 

 

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 393-396

 

Preparation and performance of new base fuel antioxidant based on hindered phenol and heterocyclic amine

 

Jigar Desaia, A N Misrab & K B Naira*

 

1-Phenyl-4-(3¢,5¢-di-tert-butyl-4¢-hydroxybenzyl) piperazine was prepared and its synthesis, spectral characterisation and thermal stability are reported along with its characteristic as antioxidant in base fuel. The effectiveness of the synthesized antioxidant was compared with that of the commercially available antioxidant. The newly synthesized antioxidant was found to possess excellent thermal stability and comparable antioxidant activity

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 397-401

 

 

 

 

Kinetic and thermodynamic studies on adsorption of fluoride by dolomite

 

G Karthikeyan*, Anitha Pius & G Alagumuthu

 

Batch adsorption studies were carried out to determine the effect of adsorbent dose, initial adsorbent concentration and temperature on the adsorption of fluoride by naturally occurring dolomite. The adsorption of fluoride was found to depend on temperature and concentration. The adsorption process followed first-order kinetics. The mechanism of adsorption obeyed Langmuir adsorption isotherm indicating an unimolecular layer pattern. Dolomite possesses considerable defluoridation efficiency at neutral pH and hence can be an effective defluoridating material. Thermodynamic studies revealed that the adsorption of fluoride by dolomite is an endothermic process, showing increase in sorption at higher temperature. Also, negative values of ∆Go indicate the spontaneity of the sorption process.

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 402-406

The thermodynamics of systems at negative absolute temperatures

 

Jaime Wisniak*

 

The application of the laws of thermodynamics is analyzed for the case that a system exists in the domain of negative absolute temperature. It is shown that irreversible processes are accompanied by an increase in entropy, but that it is possible to convert heat totally into work. In addition, it is impossible to convert work totally into heat and work must be added to the system to transfer thermal energy from a cold source to a hot one.

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 407-410

 

Effect of temperature on pitting corrosion of 316 SS in concentrated phosphoric acid containing hydrochloric acid

 

M M Singh, Rita Khare & A K Mukherjee*

 

Anodic polarization experiments were conducted on AISI 316 SS in 14 M H3PO4, containing 0-0.55 M of HCl at 298, 308 and 318 K. The anodic parameters ic, ip, Epp, Ep and Eb were determined from the anodic polarization curves. It was found that both critical current density, ic and passivity current density, ip increased with rise in temperature. The parameters Epp, Ep and Eb attained more active values with rise in temperature within the range of HCl concentrations investigated. Potential decay experiments were carried out to determine the characteristics of the passive films formed on 316 SS, which were found to be temperature dependent – their porosity increasing with rise in temperature. The pitting potential, Epit and protection potential, Epr were determined for various HCl concentrations using the reverse polarization technique.

 

 

Indian Journal of Chemical Technology

Vol.9, September 2002, pp. 411-414

 

 

 

Pb3BrF5: A lead halo composite as catalyst for allylation reactions

 

N K Kala Raj*, C S Sajanikumari, I R Unni, S B Halligudi & C Gopinathan*

 

The solid lead halo composite Pb3BrF5, has been found to be an active reagent in the allylation of anisole, phenol and diphenyl ether (dpe). This catalyst favoured the formation of monoallylated products with all the three substrates, showing higher selectivity for para isomers. Side products of allylation of phenol were allyl phenyl ether and 1,3-bis (2-hydroxy phenyl) propane, and for anisole and dpe, their respective diallylated products. The lead halo composite adsorbs HBr (formed in the reaction) and prevents the occurrence of consecutive reactions.

 

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 415-419

 

 

Process monitoring of Dibenz-[b,f]-1,4-Oxazepine (CR) by gas

chromatographic method

 

 

Bidhan Chandra Bag & M P Kaushik*

 

Dibenz (b,f)-1,4-oxazepine (CR) is a new nontoxic skin irritant and is very useful as a riot control agent. A simple, specific and rapid Gas Chromatographic method with flame ionization detection for the determination of CR and its precursors and the process monitoring of the CR production is described. After a concise sample preparation, samples were injected on Gas Chromatograph (GC) column at 200°C for o-chlorobenzaldehyde (OCB) and 250°C for CR. In monitoring the process it was observed that in the first reaction 96.6% OCB was converted to Schiff’s base (SB) within 25 min and 75% of potassium salt so formed by the reaction of SB with methanolic potassium hydroxide was converted into CR in 160 min. Repeatability of the described gas chromatographic method was evaluated by analyzing five replicates of the samples of OCB, SB and CR.

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 420-423

 

 

Synthesis and analytical application of lead selective thorium iodate
cation exchanger

M Jitha Kunhikrishnan & C Janardanan*

 

A new inorganic ion exchanger thorium iodate was synthesized and characterized by studying the properties like ion exchange capacity, pH titration curves, distribution coefficients for various metal ions, effect of hydrated ionic radii, temperature, electrolyte concentration, etc. on the ion exchange capacity. The empirical formula proposed for the ion exchanger is ThO2.I2O5.nH2O. Important binary as well as ternary separations were carried out. The synthetic utility of the exchanger is revealed from the separation studies. The separation performed on the ion exchanger column is very important for the environmentalists, since the mixtures analysed are Cu2+-Pb2+, Ni2+-Pb2+, Cd2+-Pb2+ and Hg2+-Pb2+.

 

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 424-427

 

 

Solvent extraction separation of palladium(II) with
2-oxo-4’-hydroxyphenylacetaldehyde oxime

 

Shilpa S Utekar, S B Jadhav & S P Malve*

 

The optimum extraction conditions have been evaluated by studying various parameters such as acidity, reagent concentration, equilibration period, diluent effect and effect of diverse ions for the separation of palladium(II) using 2-oxo-4’-hydroxy-phenylacetaldehyde oxime (HOHPO). Palladium(II) was quantitatively extracted with HOHPO from 0.2 M acetic acid medium into chloroform. The extracted yellow coloured complex showed maximum absorption at 420 nm. The nature of the extracted species was determined by the plot of log D versus log [HOHPO]. Palladium(II) was separated from number of elements with which it is generally associated. The method was extended for the analysis of synthetic mixtures and some real samples.

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 428-431

 

 

Sensitive spectrophotometric method for the determination of pefloxacin

 

K Basavaiah* & H C Prameela

 

A simple and sensitive spectrophotometric method is developed for the determination of pefloxacin in pure drug and in pharmaceutical preparations. The method is based on the reaction of pefloxacin with Folin-Ciocalteu reagent in sodium carbonate solution resulting in the formation of a blue coloured chromogen with an absorption maximum at 760 nm. Beer’s law is obeyed in the concentration range 10-45 mg mL-1of pefloxacin, the molar absorptivity and Sandell sensitivity being 2.79´103 l mol-1 cm-1 and 119.03 ng cm-2, respectively. The reaction variables have been optimised. When pharmaceutical preparations containing pefloxacin were analysed, the results obtained by the proposed method were in good agreement with the labeled amounts. The results of analysis have been validated statistically and by recovery studies.

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 432-437

 

 

 

Chromatographic behaviour of some synthetic dyes on unconventional layers

 

Aditya K Misra *, Pankaj S Saxena & Upasana Gupta

 

The thin layer chromatographic behaviour of some synthetic dyes has been studied on egg shell layers in various organic solvents and inorganic salt solutions. The mobility of the dyes was found to depend on the polarity of the solvents. Ketones gave compact spots of dyes.

A large number of difficult separation of analytical interest have been achieved on the basis of RT-RL value. The results are compared with the chromatographic behaviour of phenols to establish the separation potential of the egg shell layer in pollution studies.

 

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 438-441

 

 

Determination of the limiting current density through potential step measurements

R Fuchs-Godec*, A Petek & V Doleček

 

Processes such as anodic dissolution, prepassive film formation (salt and/or oxide, hydoxide film), and passive film formation are in the initial stage controlled by diffusion. Information about the value of the limiting current density (id) is needed for understanding the kinetics of passive film formation. In this study an alternative method, suitable for the determination of the id through potential step measurements, is proposed. The method is based on the assumption that the reaction cannot proceed faster than that allowed by the id. In this case, the maximum reaction rate corresponds to the current density at the inflection point of the i-t curve, and this current density is identified as the limiting current density. This method was used to determine the id values of some Cr-13% stainless steels at five passive potentials in mixtures of 0.1 M H2SO4 + 0.1 M Na2SO4 with different pH values. The results for the limiting current density were compared with the corresponding id values obtained from the diffusion overvoltage equation. The agreement between the two methods is satisfactory.

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 442-445

 

Spray drying of beet root juice using different carriers

 

V K Koul*, M P Jain, Suman Koul, V K Sharma, C L Tikoo & S M Jain

 

he present work describes the process of spray drying of betalain dye from red beet roots using different carriers. The carriers used are malto dextrine, gum acacia and soluble starch. Effect of these carriers, in varying percentages, with freshly extracted beet root juice was studied during spray drying. The chamber temperature of spray drier was maintained in the range of 150°-165°C. These studies showed that with decrease in percentage of carriers in the juice, the percent yield of betalains increased. This was observed by optical density and betalain content estimation. The shelf life studies of this spray dried betalain dye powder, over 180 days showed that the dye is quite stable in the temperature range of - 4°C to 20°C.

 

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 446-449

 

 

Ferroconvection in an anisotropic densely packed porous medium

 

G Vaidyanathana, R Sekarb  & A Ramanathanc

 

Ferrofluids find immense applications in various fields of science, engineering, medicine and agriculture. The study of convection in ferro-fluids is quite interesting especially when magnetic particles can be treated as suspension of particles represented as porous medium in presence of carrier fluids. These suspended particles need not constitute uniform distribution, there can be some amount of anisotropy in the distribution. In this paper ferroconvective instability in an anisotropic densely packed magnetic particle, treated as porous medium, is studied. The anisotropy is assumed to be along the vertical direction. It is found that the presence of porous medium inhibits the convection and anisotropy favours the convection.

 

 

Indian Journal of Chemical Technology

Vol. 9, September 2002, pp. 450-463

 

 

 

The history of chlorine¾From discovery to commodity

 

Jaime Wisniak*

 

Chlorine was the first of the halogens to be discovered and identified. The discovery of the last one, bromine, represented one of the first experimental evidences that elements could be grouped in families of similar properties. From a controversial scientific subject and a laboratory curiosity chlorine grew to become the eighth largest chemical commodity in the world. The regulations that followed the negative ecological impact of the Leblanc soda process were the jumping board for the beginning of large-scale production of chlorine for bleaching purposes. Transformation of the new element and its derivatives into a substantial commercial reality came with the mass production of automobiles and chlorofluorohydrocarbons. The pattern end use of chlorine has reflected the changes in social appreciation of environmental protection and safety.