scholarly journals CMC Determination and Thermodynamic Micellisation Of NPE Surfactant In Aqueous And CH3OH – H2O Solvents

2013 ◽  
Vol 10 (3) ◽  
pp. 1050-1056
Author(s):  
Baghdad Science Journal
Keyword(s):  
Surface Tension ◽  
Free Energy ◽  
Critical Micelle Concentration ◽  
Binary Mixture ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Standard Gibbs Free Energy ◽  
Good Linearity ◽  
Methanol Solutions ◽  
Compensation Behavior

The critical micelle concentration (CMC) of nonylphenolethoxylate (NPE) surfactant has been determined by measuring the surface tension as a function of the molar concentration of the surfactant in aqueous and binary mixture of water + methanol solutions at a temperature range from 20?C to 35?C. The interfacial parameters ?max, Amin, ?cmc and ?G?ads were calculated. The results indicate that the CMC increases as the temperature increases and that the addition of methanol the CMC decreases. The thermodynamic parameters such as standard Gibbs free energy (?G?), enthalpy (?H?), and entropy (?S?) of micellization were estimated using the change of CMC with temperature. The enthalpy – entropy compensation behavior of the surfactant was evaluated and a good linearity in the compensation plot has been observed.

Standard Gibbs free energy of formation of ZrOS

1990 ◽  
Vol 163 (1) ◽  
pp. 109-113 ◽  
Author(s):  
Zhi-Tong Sui ◽  
Xing-Yi Xiao ◽  
Ke-Qin Huang ◽  
Chang-Zhen Wang
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Standard Gibbs Free Energy ◽  
Free Energy Of Formation ◽  
Energy Of Formation

Absorption Equilibrium and Thermodynamics of Fenugreek Yellow Pigment on Macroporous Resins

2011 ◽  
Vol 233-235 ◽  
pp. 91-94
Author(s):  
Feng Han ◽  
Wen Hong Li ◽  
Xuan Tang ◽  
Dong Li
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Adsorption Equilibrium ◽  
Yellow Pigment ◽  
Adsorption Models ◽  
Freundlich Model ◽  
Langmuir Adsorption ◽  
Macroporous Resins ◽  
Equilibrium Data

The adsorption equilibrium and thermodynamics of pigment extracted from Fenugreek after degumming on macroporous resins was investigated under differentinitial concentrations. The suitability of the Freundlich and Langmuir adsorption models to the equilibrium data was investigated. The model fitness was determined by R2 . Thermodynamic parameters were calculated by the Van’t Hof equation.The results showed that Freundlich model gave a better fit of adsorption isotherms than Langmuir models. The positive value of enthalpy(∆H) indicated that the adsorption was endothermic, the negative value of Gibbs free energy (∆G) showed the spontaneous and favoured nature of adsorption, and the entropy(∆S) was positive.The resins LS-46 showed an effective adsorbtion for Fenugreek yellow pigment.

scholarly journals Standard Gibbs Free Energy Changes for the Formations of Ga and In Sulfides

1991 ◽  
Vol 55 (9) ◽  
pp. 945-950 ◽  
Author(s):  
Noriyuki Tatsumi ◽  
Shunsuke Toyoda ◽  
Ryokichi Shimpo ◽  
Yasushi Nakamura
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Standard Gibbs Free Energy

Synthesis and Properties of Anionic Maleic Monoester Carboxylate Polymeric Surfactants

2014 ◽  
Vol 1033-1034 ◽  
pp. 26-29
Author(s):  
Ling Dong ◽  
Ke Ming Xu ◽  
Bao Hui Wang ◽  
Cheng Chen
Keyword(s):  
Surface Tension ◽  
Critical Micelle Concentration ◽  
Maleic Anhydride ◽  
Sodium Hydroxide ◽  
Thermodynamic Parameters ◽  
Chain Length ◽  
High Adsorption ◽  
Polymeric Surfactants ◽  
Good Surface ◽  
Linear Alcohols

Four anionic maleic monoester carboxylate polymeric surfactants were synthesized by the reaction of maleic anhydride with linear alcohols of different chain length in the ratio of 1:1.1 under 80 °C. Then the intermediate products were neutralized by sodium hydroxide at 60 °C to produce the final monomers. The structures of products were confirmed by FTIR. The surface tension was measured at 45 °C and the thermodynamic parameters were calculated. The results show that the polymeric surfactants possess low critical micelle concentration (CMC), high adsorption affinities and good surface and interfacial activity.

Sign in / Sign up

Export Citation Format

Share Document