Ratna Shukla
@csjmu.ac.in
Assistant Professor, Chemistry
Chattrapati Shahu ji Maharaja University, Kanpur, India
EDUCATION
Ph.D. in chemistry
RESEARCH, TEACHING, or OTHER INTERESTS
Chemistry, Colloid and Surface Chemistry, Management Information Systems
Scopus Publications
Scopus Publications
P. S. Niranjan, Ratna Shukla, and Santosh K. Upadhyay
Wiley
AbstractThe 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.
Ratna Shukla and Santosh K. Upadhyay
Elsevier BV
Ratna Shukla, Neelu Kambo, and Santosh K. Upadhyay
Informa UK Limited
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.
Ratna Shukla and Santosh K. Upadhyay
Wiley
AbstractThe 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