Ratna Shukla

EDUCATION

Ph.D. in chemistry

RESEARCH, TEACHING, or OTHER INTERESTS

Chemistry, Colloid and Surface Chemistry, Management Information Systems

Scopus Publications

Interactions of polyacrylamide with cationic surfactants: Thermodynamic and surface parameters
P. S. Niranjan, Ratna Shukla, Santosh K. Upadhyay
Journal of Surfactants and Detergents, 2012
The aggregation behaviour of two cationic surfactants, viz. cetyl trimethyl ammonium bromide (CTAB) and N‐cetyl pyridinium chloride (CPC), in different concentrations of water‐soluble polyacrylamide has been studied in alkaline medium by electrical conductivity and surface tension measurements. A decrease in the critical micelle concentration (CMC) of the surfactant with an increase in polymer content in the mixture was observed. The thermodynamic and surface parameters have been determined and discussed. The results indicate that micellisation becomes more favourable at higher polymer content.
Tween-80 catalysis in the oxidation of methionine and proline by alkaline hexacyanoferrate(III)
Ratna Shukla, Santosh K. Upadhyay
Colloids and Surfaces A Physicochemical and Engineering Aspects, 2008
Inhibition effect of {Cationic Surfactant-Ascorbic Acid} premicellar aggregation on the rate of hexacyanoferrate(III) oxidation of ascorbic acid: A kinetic study
Ratna Shukla, Neelu Kambo, Santosh K. Upadhyay
Journal of Dispersion Science and Technology, 2008
The kinetics of oxidation of ascorbic acid by acidic hexacyanoferrate(III) have been investigated in presence of cationic surfactant viz. cetyltrimethylammonium bromide (CTAB). An inhibition effect of CTAB (below its critical micelle concentration) on the rate of oxidation has been observed. The spectrophotometric and kinetic data support a 1:1 premicellar association between substrate and surfactant. A mechanism has been proposed and a rate law consistent with kinetic results has been derived.
Non-ionic micellar inhibition on the rate of oxidation of 1-histidine by alkaline hexacyanoferrate(III)
Indian Journal of Chemistry Section A Inorganic Physical Theoretical and Analytical Chemistry, 2008
Inhibition effect of {surfactant-substrate} aggregation on the rate of oxidation of reducing sugars by alkaline hexacyanoferrate(III)
Ratna Shukla, Santosh K. Upadhyay
International Journal of Chemical Kinetics, 2007
The effect of cationic (cetyltrimethylammonium bromide, CTAB), anionic (sodium lauryl sulfate, NaLS), and nonionic (Brij‐35) surfactants on the rate of oxidation of some reducing sugars (xylose, glucose, and fructose) by alkaline hexacyanoferrate(III) has been studied in the temperature range from 35 to 50°C. The rate of oxidation is strongly inhibited in the presence of surfactant. The inhibition effect of surfactant on the rate of reaction has been observed below critical micelle concentration (CMC) of CTAB. In case of NaLS and Brij‐35, the inhibition effect was above CMC, at which the surfactant abruptly associates to form micelle. The kinetic data have been accounted for by the combination of surfactant molecule(s) with a substrate molecule in case of CTAB and distribution of substrate into micellar and aqueous pseudophase in case of NaLS and Brij‐35. The binding parameters (binding constants, partition coefficients, and free‐energy transfer from water to micelle) in case of NaLS and Brij‐35 have been evaluated with the help of Menger and Portnoy model reported for micellar inhibition. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 595–604, 2007
Inhibition effect of Brij-35 on the rate of oxidation of ascorbic acid by hexacyanofer-rate(III) in acidic medium: A kinetic study
Indian Journal of Chemistry Section A Inorganic Physical Theoretical and Analytical Chemistry, 2007