The liquid membrane oscillation of a novel water （aqueous tetradecyl trimethyl ammoniumbromide, TTAB and alcohol solution）/oil （picric acid in chloroform solution）/water （aqueous glucose solution） system was inv...The liquid membrane oscillation of a novel water （aqueous tetradecyl trimethyl ammoniumbromide, TTAB and alcohol solution）/oil （picric acid in chloroform solution）/water （aqueous glucose solution） system was investigated. By using homemade device, the curves of various liquid membranes oscillation with different concentration of TTAB and picric acid, types of alcohol and other organic solvents at different temperature were measured. The results show that the water （aqueous 7 mmol/L of TTAB and 0.5 mol/L of n-propanol solution）/oil （0.5 mmol/L of picric acid in chloroform solution）/water （aqueous glucose solution） system performed sustained and stable oscillation at 30 ℃. And the novel system can recognise added amino acid.展开更多
Herein,the interaction of a protein,bovine serum albumin(BSA),with tetradecyltrimethylammonium bromide(TTAB,a cationic surfactant),has been investigated using the conductivity measurement technique in pure water and s...Herein,the interaction of a protein,bovine serum albumin(BSA),with tetradecyltrimethylammonium bromide(TTAB,a cationic surfactant),has been investigated using the conductivity measurement technique in pure water and some sodium salts(NaCl,Na_(2) SO_(4),Na_(2) CO_(3), and Na_(3) PO_(4)) solutions at temperature range of 295.15-320.15 K.Results reveal that,in the plot of specific conductivity versus the concentration of TTAB,only a single critical micelle concentration(cmc) was found for the TTAB+BSA mixed system in all solvents media studied.The addition of BSA in aqueous TTAB solution,the value of cmc undergoes a change from its pure form,which indicates the presence of strong interaction operating between the BSA and TTAB molecules.In aqueous system,the cmc values of the TTAB+BSA mixtures are obtained higher compared to the values found for single TTAB surfactant However,the addition of salt decreases the cmc value of mixed TTAB+BSA system.The values of cmc of the BSA+TTAB mixed system at 310.15 K and 1.00 mmol·kg^(-1) ionic strength of salt followed the order:cmc_(Na_(2) CO_(3))> Cmcc_(Na_(3) PO_(4))> cmcNaCl>cMC_(Na_(2) SO_(4)).The cmc values of TTAB+BSA mixture were found to be lowered in urea solution within the concentrations studied.The values of degree of dissociation(α) and fraction of counter ion binding(β) were found to be dependent on additives and temperature.The free energy of micellization(AGm) is negative for all the systems,which manifests that the micellization phenomenon is energetically spontaneous.The enhancement of the negative value of △G_(m)^(0) in aqueous salt solutions reveals an increase of spontaneity of the TTAB+BSA micellization process.The values of △G_(m)^(0) also reveal that the spontaneity of micelle formation is enhanced at higher temperatures in all media studied.The values of free energy of transfer(△G_(m,t)^(o)) were also determined for numerous solvent media used in the present study and described with appropriate reasoning.展开更多
文摘The liquid membrane oscillation of a novel water （aqueous tetradecyl trimethyl ammoniumbromide, TTAB and alcohol solution）/oil （picric acid in chloroform solution）/water （aqueous glucose solution） system was investigated. By using homemade device, the curves of various liquid membranes oscillation with different concentration of TTAB and picric acid, types of alcohol and other organic solvents at different temperature were measured. The results show that the water （aqueous 7 mmol/L of TTAB and 0.5 mol/L of n-propanol solution）/oil （0.5 mmol/L of picric acid in chloroform solution）/water （aqueous glucose solution） system performed sustained and stable oscillation at 30 ℃. And the novel system can recognise added amino acid.
基金King Saud University for funding this work through Researchers Supporting Project number (RSP-2020/133), King Saud University, Riyadh, Saudi Arabia。
文摘Herein,the interaction of a protein,bovine serum albumin(BSA),with tetradecyltrimethylammonium bromide(TTAB,a cationic surfactant),has been investigated using the conductivity measurement technique in pure water and some sodium salts(NaCl,Na_(2) SO_(4),Na_(2) CO_(3), and Na_(3) PO_(4)) solutions at temperature range of 295.15-320.15 K.Results reveal that,in the plot of specific conductivity versus the concentration of TTAB,only a single critical micelle concentration(cmc) was found for the TTAB+BSA mixed system in all solvents media studied.The addition of BSA in aqueous TTAB solution,the value of cmc undergoes a change from its pure form,which indicates the presence of strong interaction operating between the BSA and TTAB molecules.In aqueous system,the cmc values of the TTAB+BSA mixtures are obtained higher compared to the values found for single TTAB surfactant However,the addition of salt decreases the cmc value of mixed TTAB+BSA system.The values of cmc of the BSA+TTAB mixed system at 310.15 K and 1.00 mmol·kg^(-1) ionic strength of salt followed the order:cmc_(Na_(2) CO_(3))> Cmcc_(Na_(3) PO_(4))> cmcNaCl>cMC_(Na_(2) SO_(4)).The cmc values of TTAB+BSA mixture were found to be lowered in urea solution within the concentrations studied.The values of degree of dissociation(α) and fraction of counter ion binding(β) were found to be dependent on additives and temperature.The free energy of micellization(AGm) is negative for all the systems,which manifests that the micellization phenomenon is energetically spontaneous.The enhancement of the negative value of △G_(m)^(0) in aqueous salt solutions reveals an increase of spontaneity of the TTAB+BSA micellization process.The values of △G_(m)^(0) also reveal that the spontaneity of micelle formation is enhanced at higher temperatures in all media studied.The values of free energy of transfer(△G_(m,t)^(o)) were also determined for numerous solvent media used in the present study and described with appropriate reasoning.
