Studies of interaction between ninhydrin and Gly-Leu dipeptide: Influence of cationic surfactants (m-s-m type Gemini)

J of Physical Organic Chem

et al. 2019

Self Cite

Herein, the cloud points (CPs) of tween 80 (Tw 80) in water/(water + diols [ethanediol, propanediol, and butanediol])/(water + polyols [glucose, fructose, and sorbitol]) systems were measured. For diols‐Tw 80‐water system and polyols‐Tw 80‐water system, the CP values were obtained to reduce gradually with increasing content of diols and polyols at a particular concentration of Tw 80. For a certain concentration of Tw 80 having different contents of diols, the observed ∆H0c, as well as ∆S0c values, were negative over the range of concentration of diols studied, and the negative values of ∆H0c and ∆S0c were reduced with the enhancement of the content of diols. The values of ∆H0c were negative, which indicate the process was exothermic. The clouding process of Tw 80 in the presence of different diols is mainly enthalpy‐controlled process, while the contributions of enthalpy tend to reduce with enhancing of the contribution of diols. In the case of polyols‐Tw 80 mixture in an aqueous environment, the ∆Gc0 values were achieved positive. The values of ∆Hc0 and ∆Sco were obtained negative for studied systems, while the negative values reduce with enhancing of polyol (glucose and fructose) concentrations. For sorbitol‐Tw 80 system, the values of ∆Hc0 were observed to be negative and the negative magnitudes reduce with enhancing of sorbitol concentrations. The thermodynamic parameters of transfer are also evaluated and illustrated in detail.

Section: Resultsmentioning

confidence: 82%

Section: Resultsmentioning

confidence: 89%

Impact of different diols/polyols on the phase separation behavior as well as thermodynamic properties of tween 80

Mishu

Amin

J of Physical Organic Chem

et al. 2019

Self Cite

“…By using these results, different activation parameters were calculated by linear least-squares regression procedure. The mechanism of amino acids with ninhydrin has received great attention of researchers/investigators due to the use in different fields [47][48][49][50][51]. The proposed mechanism for the current study of ninhydrin and histidine is demonstrated in scheme 1.…”

Section: Effect Of Several Parameters On K ψmentioning

confidence: 99%

Catalytic influence of 16- s -16 gemini surfactants on the rate constant of histidine and ninhydrin

Kumar

2020

R. Soc. open sci.

Self Cite

The present paper reports the catalytic influence of 16-s-16 (spacer (s) = 4, 5, 6) gemini surfactants on the rate constant of histidine and ninhydrin at 343 K and pH 5.0 using the spectrophotometric technique. The effect of varying amounts of geminis was made on the rate constant of histidine and ninhydrin keeping other constituents constant. Characteristics of the rate constant (k ψ ) versus [gemini] depict the effect of surfactants on the rate constant. A systematic explanation about the effect of surfactants is revealed and discussed in the text. The influence of different parameters that includes [reactants], temperature and pH has also been performed on the study. In order to determine the critical micelle concentration (cmc) of pure surfactants and their solution mixtures, conductivity measurement was employed. By using the Eyring equation, activation parameters at different temperatures have been obtained. The resultant data of k ψ versus [gemini] plot were rationalized with the pseudo-phase model of micelles.

“…That is, two conventional surfactant monomers are joined together via a spacer. [27][28][29][30][31] Gemini surfactants show lower cmc, better surface activity, super wetting power and a low Kra point over traditional single chain surfactants (single hydrophilic head and single hydrophobic tail). 24,[32][33][34][35] Gemini surfactants appeal for present consideration in surface science due to their unusual properties.…”

Section: Introductionmentioning

confidence: 99%

Study of the reaction of ninhydrin with tyrosine in gemini micellar media

Kumar

2019

RSC Adv.

Self Cite