Interaction of cationic surfactant with acid yellow dye in absence/presence of organic and inorganic additives: conductivity and dye solubilization methods

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Md. Ariful Haque ◽  
Shamim Mahbub ◽  
Mohammad Majibur Rahman ◽  
Md. Anamul Hoque ◽  
Dileep Kumar ◽  
...  
Keyword(s):  
Free Energy ◽  
Cationic Surfactant ◽  
Cetyltrimethylammonium Bromide ◽  
Micelle Formation ◽  
Aqueous System ◽  
Nacl Solution ◽  
Solubilization Capacity ◽  
Delta G ◽  
Free Energy Of Micellization ◽  
Dye Solubilization

Abstract In the present study, the conductometric and dye-solubilization techniques have been utilized to investigate the interaction between an anionic dye (acid yellow 23 [AY]) and a cationic surfactant (cetyltrimethylammonium bromide [CTAB]) in presence of organic (ethanol)/inorganic (NaCl) additives. From the conductometric method, two critical micelle concentrations (cmc) were found for AY + CTAB mixture in an aqueous system and the cmc values were found to undergo a change with the variation of AY concentrations. The cmc values of AY + CTAB systems were observed higher in the alcoholic medium, while the same was found to be lower in the NaCl solutions. The change in cmc of AY + CTAB systems shows an U-like curve with an increase of temperature. The negative free energy of micellization ( Δ G m o ${\Delta}{G}_{m}^{o}$ ) for the AY + CTAB systems has indicated a spontaneous micelle formation in all of the cases studied. The enthalpy ( Δ H m o ${\Delta}{H}_{m}^{o}$ ), as well as the entropy of micellization ( Δ S m o ${\Delta}{S}_{m}^{o}$ ) for the AY + CTAB systems, were assessed and discussed with proper reasoning. Additionally, the enthalpy-entropy compensation parameters were also investigated and illustrated. The solubility of AY and C D was observed to rise linearly with an increase in the concentration of CTAB/NaCl solution. The solubilization capacity (χ) of AY, the molar partition coefficient (K M) amongst the micellar and the aqueous phase, and free energy of solubilization ( Δ G S o ${\Delta}{G}_{S}^{o}$ ) were evaluated and discussed in detail. The former parameters undergo an increase with an increase of NaCl concentrations.

Impacts of polyols and temperature on the micellization, interaction and thermodynamics behavior of the mixture of tetradecyltrimethylammonium bromide and polyvinyl alcohol

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sharmin Sultana ◽  
Abdullah Al Mamun ◽  
Shahina Aktar ◽  
Shamim Mahbub ◽  
Kareem Yusuf ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Polyvinyl Alcohol ◽  
Hydrophobic Interactions ◽  
Specific Conductivity ◽  
Mixed Solvents ◽  
Conductivity Measurement ◽  
Micelle Formation ◽  
Tetradecyltrimethylammonium Bromide ◽  
Delta G ◽  
Free Energy Of Micellization

Abstract Herein, the aggregation manner of the mixture of polyvinyl alcohol (PVA) and tetradecyltrimethylammonium bromide (TTAB) was performed in polyols (glucose, maltose and galactose) media over 300.55–320.55 K temperatures range with 5 K interval through conductivity measurement method. The micelle formation of TTAB + PVA mixture was identified by the assessment of critical micelle concentration (CMC) from the plots of specific conductivity (κ) versus TTAB concentration. The degree of micelle ionization (α), the extent of bound counter ions (β) as well as thermodynamic properties ( Δ G m 0 ${\Delta}{G}_{m}^{0}$ , Δ H m 0 ${\Delta}{H}_{m}^{0}$ and Δ S m 0 ${\Delta}{S}_{m}^{0}$ ) of TTAB + PVA systems have been estimated. The CMC values reveal that the micelle formation of TTAB + PVA mixture experience an enhancement in the manifestation of polyols. The values of free energy of micellization ( Δ G m 0 ${\Delta}{G}_{m}^{0}$ ) are negative for the TTAB + PVA system in aqueous polyols media, suggesting a spontaneous aggregation phenomenon. The Δ H m 0 ${\Delta}{H}_{m}^{0}$ and Δ S m 0 ${\Delta}{S}_{m}^{0}$ values of TTAB + PVA systems direct that the PVA molecule interacts with TTAB through the exothermic, ion-dipole, and hydrophobic interactions. The thermodynamic properties of transfer were also determined for the move of TTAB + PVA mixture from H2O to water + polyols mixed solvents. The values of compensation temperature (T c) and intrinsic enthalpy gain ( Δ H m 0 , ∗ ${\Delta}{H}_{m}^{0,\ast }$ ) were evaluated and discussed for the studied system.

Interaction of Porphyrins with Cetyltrimethylammonium Bromide Micelles in Methylene Chloride

1998 ◽  
Vol 02 (04) ◽  
pp. 345-351 ◽  
Author(s):  
NILKAMAL BAG ◽  
ARUNA DHATHATHREYAN ◽  
ASIT BARAN MANDAL ◽  
TIRUMALACHARI RAMASAMI
Keyword(s):  
Free Energy ◽  
Cetyltrimethylammonium Bromide ◽  
Methylene Chloride ◽  
Aggregation Number ◽  
Film Formation ◽  
Cetylpyridinium Chloride ◽  
Standard Free Energy ◽  
Micelle Formation ◽  
Standard Free Energy Change ◽  
Biphasic Model

The formation of micelles of cetyltrimethylammonium bromide (CTAB) in CH 2 Cl 2 solution has been reported for the first time. The critical micelle concentrations (cmc) of CTAB in CH 2 Cl 2 solution were determined using conductivity and fluorescence techniques in both the absence and presence of 1,3,5,7-tetramethyl-2,4,6,8-tetra(2,4,6-triisopropylphenyl)porphyrin (TMTIP). The cmc values obtained by conductivity and fluorescence methods were found to be 75 and 78 mM, respectively. The aggregation numbers (N) of CTAB and porphyrin–CTAB in CH 2 Cl 2 solution were determined using pyrene and N-cetylpyridinium chloride (CPC) as the fluoroprobe and quencher, respectively. The N of CTAB in CH 2 Cl 2 solution was also determined using the porphyrin (in lieu of pyrene) as the fluoroprobe and CPC as the quencher. The N of CTAB obtained by these probes was found to be 134 ± 3 and 140 ± 5, respectively. This suggests that the porphyrin could be used as an excellent fluoroprobe for determination of the aggregation number of CTAB micelles. The results of both cmc and aggregation number suggest that the micelle formation of CTAB in CH 2 Cl 2 solution is favored in the presence of the porphyrin. The standard free energy change for micelle formation of CTAB in CH 2 Cl 2 solution was calculated using a biphasic model. The standard free energy transfer [Formula: see text] of CTAB micelles from CH 2 Cl 2 to porphyrin environment has been found to be −1.0 kJ mol−1 at 25 °C, suggesting that the above transfer is difficult. However, the reverse situation, i.e. binding of the porphyrin to CTAB micelles, is more probable. The Langmuir–Blodgett (LB) film formation of the porphyrin and metalloporphyrins ( Fe , Co , Cu , Zn ) has also been studied and the UV-vis spectra of these films have been analyzed.

Impact of salts on the phase separation and thermodynamic properties of mixed nonionic surfactants in absence/attendance of polyvinyl alcohol

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Md Ackas Ali ◽  
Md. Ruhul Amin ◽  
Shamim Mahbub ◽  
Md. Delwar Hossen ◽  
Md. Anamul Hoque ◽  
...  
Keyword(s):  
Free Energy ◽  
Polyvinyl Alcohol ◽  
Aqueous Medium ◽  
Standard Free Energy ◽  
Tween 80 ◽  
Aqueous System ◽  
Standard Entropy ◽  
Thermodynamic Variables ◽  
Delta G ◽  
Energy Of Transfer

Abstract Mixed surfactant systems are used in different applied fields like pharmaceutical formulation rather than single surfactant. Therefore, the determination of the clouding nature of the triton X-100 (TX-100) + Tween 80 (TW-80) mixture was carried out in H2O and polyvinyl alcohol (PVA). In the occurrence of PVA, the cloud point (CP) values of TX-100 initially enhance with enhancing the concentration of PVA and tend to decrease after a certain concentration. For different ratios of TX-100 and TW-80 mixture having the same concentration of both solutions, CP values increase through the decreasing ratios of TX-100 with/without PVA. In the presence of polymer, at higher ratios of TX-100 than TW-80, the CP values are higher in magnitudes in comparison to the aqueous medium but at lower ratios of TX-100, the value of CP are lower in magnitudes in comparison to the aqueous system. The CP values of the TX-100 + TW-80 mixture in the salt system are lower in magnitudes than the aqueous medium in both the absence/presence of PVA. However, a reduction of CP values was obtained to a large extent for Na2SO4 over NaCl in the case of lower volume ratios of TX-100. Various thermodynamic variables (standard free energy ( Δ G c o ${\Delta}{G}_{c}^{o}$ ), standard enthalpy ( Δ H c o ${\Delta}{H}_{c}^{o}$ ), standard entropy ( Δ S c o ${\Delta}{S}_{c}^{o}$ ) change, thermodynamic parameters of transfer (free energy of transfer ( Δ G c , t o ${\Delta}{G}_{c,t}^{o}$ ), and transfer of enthalpies ( Δ H c , t o ${\Delta}{H}_{c,t}^{o}$ )) of phase transition) were also determined.

scholarly journals Micelle formation of a non-ionic surfactant in non-aqueous molecular solvents and protic ionic liquids (PILs)

2016 ◽  
Vol 18 (35) ◽  
pp. 24377-24386 ◽  
Author(s):  
Emmy C. Wijaya ◽  
Frances Separovic ◽  
Calum J. Drummond ◽  
Tamar L. Greaves
Keyword(s):  
Free Energy ◽  
Ionic Liquids ◽  
Energy Density ◽  
Micelle Formation ◽  
Ionic Surfactant ◽  
Protic Ionic Liquids ◽  
Diverse Range ◽  
Cohesive Energy Density ◽  
Free Energy Of Micellization ◽  
Molecular Solvents

Micelle formation of a non-ionic amphiphile, C12E6, was investigated in a diverse range of molecular solvents and protic ionic liquids (PILs). A link between the solvent cohesive energy density and the free energy of micellization was discussed.

scholarly journals FORMATION OF MICELLES OF CETYL TRIMETHYLAMMONIUM BROMIDE IN WATER-GLYCEROL SOLUTIONS

1998 ◽  
Vol 6 (7) ◽  
pp. 67-76
Author(s):  
Lavinel G. Ionescu ◽  
Sonia M. Hickel Probst ◽  
Elizabeth F. de Souza
Keyword(s):  
Free Energy ◽  
Aqueous Solutions ◽  
Entire Range ◽  
Cetyltrimethylammonium Bromide ◽  
Pure Water ◽  
Critical Micellar Concentration ◽  
Kcal Mole ◽  
Water Glycerol ◽  
Free Energy Of Micellization ◽  
Surface Tensiometry

The micellization of cetyltrimethylammonium bromide (CTAB) in glycerol and aqueous solutions of glycerol was studied by means of surface tensiometry. The critical micellar concentration (CMC) was determined at 25 °C and 40 Δ C, and thermodynamic parameters such as the free energy of micellization ΔG°mis, enthalpy ΔH and entropy ΔS of micellization were also measured At 40 °C, CTAB forms micelles in pure glycerol and in the entire range of water-glycerol solutions. For 25 °C, the CMC ranged from 9.2 x 10·4 Min pure water to 8.5 x 10·3M for solutions containing 90% glycerol by volume. The corresponding values obtained/or ΔG° were -4.14 and -2.82 kcal/mole; for ΔH° were -1.03 kcal/mole and -3.73 kcal/mole and for ΔS° were + 10.43 and -3.10 e. u. The addition of glycerol decreases the spontaneity of micelles formation of CTAB in water.

scholarly journals Verification of Equation for Evaluating Dislocation Density during Steady-state Creep of Metals

2017 ◽  
Vol 6 (2) ◽  
pp. 20 ◽  
Author(s):  
Manabu Tamura
Keyword(s):  
Free Energy ◽  
Steady State ◽  
Dislocation Density ◽  
Shear Modulus ◽  
Strain Rate ◽  
Gibbs Free Energy ◽  
Steady State Creep ◽  
Austenitic Steels ◽  
Exponential Factor ◽  
Delta G

Ninety-two sets of observed dislocation densities for crept specimens of 21 types of ferritic/martensitic and austenitic steels, Al, W, Mo, and Mg alloys, Cu, and Ti including germanium single crystals were collected to verify an equation for evaluating the dislocation density during steady-state creep proposed by Tamura and Abe (2015). The activation energy, Qex, activation volume, Vex, and Larson–Miller constant, Cex, were calculated from the creep data. Using these parameter constants, the strain rate, and the temperature dependence of the shear modulus, a correction term, Gamma, was back-calculated from the observed dislocation density for each material. Gamma is defined in the present paper as a function of the temperature dependences of both the shear modulus and pre-exponential factor of the strain rate. The values of Gamma range from −394 to 233  and average 2.1 KJmol-1, which is a value considerably lower than the average value of Qex (410.4 KJmol-1), and values of Gamma are mainly within the range from 0 to 50 KJmol-1. The change in Gibbs free energy, Delta G, for creep deformation is obtained using the calculated value of , and the empirical relation Delta G~Delta GD is found, where Delta GD is the change in Gibbs free energy for self-diffusion of the main componential element of each material. Experimental data confirm the validity of the evaluation equation for the dislocation density.

scholarly journals Conductivity Study of DTAB in Water and Ethanol-Water Mixture in the Presence and Absence of ZnSO4

2020 ◽  
Vol 17 (4) ◽  
pp. 1207
Author(s):  
Sangita Acharya ◽  
Tulasi Niraula ◽  
Ajaya Bhattarai
Keyword(s):  
Free Energy ◽  
Critical Micelle Concentration ◽  
Volume Fraction ◽  
Standard Free Energy ◽  
Water Mixture ◽  
Dodecyltrimethylammonium Bromide ◽  
Degree Of Dissociation ◽  
Ethanol Content ◽  
Presence And Absence ◽  
Free Energy Of Micellization

The physicochemical behaviour of dodecyltrimethylammonium bromide (DTAB) in water and ethanol-water mixture in the presence and absence of ZnSO4 were studied by measuring the conductivity at 298.15 K. The pre-micellar (S1) and post-micellar slopes (S2) were obtained and calculated the degree of dissociation (α) and the critical micelle concentration (cmc). With an increase in ethanol content, the cmc and α of DTAB increased whereas, in the presence of ZnSO4, the cmc and α decreased. By using cmc and α, thermodynamic properties as the standard free energy of micellization ( ) were evaluated. With an increase in ethanol content, the negative values of  are decreased indicating less spontaneous in the micellization which makes micellization less favourable. The correlation of the pre-micellar and post-micellar slopes with the volume fraction of ethanol were discussed. DTAB micellization was tested in contexts of specific solvent parameters and solvophobic parameter.

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