CdS nanoparticles were prepared by reacting CdCl2 and Na2S in different microemulsions and severa... more CdS nanoparticles were prepared by reacting CdCl2 and Na2S in different microemulsions and several micellar media comprising combinations of ionic liquid, ionic, nonionic, zwitterionic amphiphiles, isopropyl alcohol, and isopropylmyristate as templates. This simple chemical method was found to be effective in the preparation of CdS dispersions mostly in the range of 3–8 nm with moderate polydispersity. The dispersions were characterized by taking UV–Vis and fluorescence spectra as well as by DLS, EDX, SEM, and TEM methods. Globular, sharp-edged elongated flake-like, and wire type morphologies were witnessed by SEM. TEM results evidenced spherical nanoentities. The dispersions witnessed both fairly and weakly semiconducting varieties; insulator-type dispersions were also observed. They have shown characteristic fluorescence properties. The nanodispersions evidenced biocidal activities toward both gram-positive and gram-negative bacteria.
Journal of Dispersion Science and Technology, 2009
APSA-80, an useful pesticide spray adjuvant is a mixture of 2-[2-(4-nonylphenoxy) ethoxy] ethanol... more APSA-80, an useful pesticide spray adjuvant is a mixture of 2-[2-(4-nonylphenoxy) ethoxy] ethanol, 1-butanol and tall oil fatty acids. It is strongly surface active and can decrease the surface tension of water to∼ 20 mNm− 1 at its critical micelle concentration (CMC) of ...
Indian journal of chemistry. Sect. A: Inorganic, physical, theoretical & analytical, 1999
The solubility/insolubility states of the nonionic surfactant Brij-56 [polyoxyethylene ( 1 0) cet... more The solubility/insolubility states of the nonionic surfactant Brij-56 [polyoxyethylene ( 1 0) cetylether], MC (methyl cellulose), Brij-56/MC and Brij-56/PVA (polyvinyl alcohol) have been studied by measuring cloud points. Considering the cloud point (CP) as the threshold temperature of solubility the energetics of the solubilization (free energy, enthalpy and entropy) of the studied pure and mixed systems have been evaluated . An attempt has been made to evidence probable interaction between the surfactant and 'the polymers . .
Interfacial and bulk properties of sodium dodecyl sulfate (SDS), polyoxyethylene (20) sorbitan mo... more Interfacial and bulk properties of sodium dodecyl sulfate (SDS), polyoxyethylene (20) sorbitan monooleate (Tween-80), and their binary mixtures in aqueous medium have been investigated using surface tension, conductance, and fluorescence measurements at ...
ABSTRACT: The micellization of an anionic gemini surfactant, (CH2)2[N(COC11H23)CH(CO2H )CH2(CO2H)... more ABSTRACT: The micellization of an anionic gemini surfactant, (CH2)2[N(COC11H23)CH(CO2H )CH2(CO2H)]2·2NaOH, abbrevi-ated as GA, having N,N-dialkylamide, carboxyl, and carboxy-late groups, in aqueous solutions of NaCl at pH 5.0 was investi-gated by means ...
Journal of Photochemistry and Photobiology B: Biology, 2016
In aqueous solution, curcumin is photodegradable (light sensitive), it is also self-degradable in... more In aqueous solution, curcumin is photodegradable (light sensitive), it is also self-degradable in the dark. In basic medium, the second process is enhanced. The dark process has been studied in water and also in a number of protic and aprotic solvents, and aqueous solutions of ionic liquids, pluronics, reverse micelles and salt. The kinetics of the process followed the first order rate law; a comparative as well as individual assessment of which has been made. The kinetics of curcumin self-degradation has been found to be fairly dependent on salt (NaCl) concentration. Curcumin molecules in solution may remain in the enol or keto-enol form. From the visible spectral analysis, an estimate of the proportions of these forms in aqueous ethanol medium has been made. The temperature effect on the visible and fluorescence spectra of curcumin has been also studied. The steady state fluorescence anisotropy of the photoactive curcumin has been evaluated in different solvent and solution media. The reversibility of the steady state fluorescence anisotropy of curcumin on heating and cooling conditions has been examined. The results herein presented are new and ought to be useful as the study of physicochemistry of curcumin has been gaining importance in the light of its biological importance.
The interaction of a cationic dye crystal violet, in aqueous solution with different types of sur... more The interaction of a cationic dye crystal violet, in aqueous solution with different types of surfactants, such as anionic, cationic, non-ionic, gemini and their mixtures has been investigated spectrophotometrically and fluorimetrically in premicellar and post micellar concentration regions. In the premicellar concentration region of anionic surfactants, the dimer of the dye is formed; in the micellar concentration region, the monomer of the dye predominates. With cationic and nonionic surfactants, crystal violet is solubilised primarily as the monomer. In case of anionic and nonionic mixture, stability of dye–surfactant complex increases with increase in mole fraction of anionic surfactant. Cationic surfactant, cetyltrimethylammonium bromide (CTAB) has no interaction with crystal violet.► Spectroscopic method is studied for interaction between crystal violet and surfactant. ► CV is used first time for the interaction with gemini surfactants spectroscopically. ► Study of absorbance and fluorescence of CV is performed in several micellar systems. ► Cationic, anionic, nonionic, gemini surfactants are used for the interaction with CV. ► Mixtures of surfactants have also been used to study the interaction with CV.
CdS nanoparticles were prepared by reacting CdCl2 and Na2S in different microemulsions and severa... more CdS nanoparticles were prepared by reacting CdCl2 and Na2S in different microemulsions and several micellar media comprising combinations of ionic liquid, ionic, nonionic, zwitterionic amphiphiles, isopropyl alcohol, and isopropylmyristate as templates. This simple chemical method was found to be effective in the preparation of CdS dispersions mostly in the range of 3–8 nm with moderate polydispersity. The dispersions were characterized by taking UV–Vis and fluorescence spectra as well as by DLS, EDX, SEM, and TEM methods. Globular, sharp-edged elongated flake-like, and wire type morphologies were witnessed by SEM. TEM results evidenced spherical nanoentities. The dispersions witnessed both fairly and weakly semiconducting varieties; insulator-type dispersions were also observed. They have shown characteristic fluorescence properties. The nanodispersions evidenced biocidal activities toward both gram-positive and gram-negative bacteria.
Journal of Dispersion Science and Technology, 2009
APSA-80, an useful pesticide spray adjuvant is a mixture of 2-[2-(4-nonylphenoxy) ethoxy] ethanol... more APSA-80, an useful pesticide spray adjuvant is a mixture of 2-[2-(4-nonylphenoxy) ethoxy] ethanol, 1-butanol and tall oil fatty acids. It is strongly surface active and can decrease the surface tension of water to∼ 20 mNm− 1 at its critical micelle concentration (CMC) of ...
Indian journal of chemistry. Sect. A: Inorganic, physical, theoretical & analytical, 1999
The solubility/insolubility states of the nonionic surfactant Brij-56 [polyoxyethylene ( 1 0) cet... more The solubility/insolubility states of the nonionic surfactant Brij-56 [polyoxyethylene ( 1 0) cetylether], MC (methyl cellulose), Brij-56/MC and Brij-56/PVA (polyvinyl alcohol) have been studied by measuring cloud points. Considering the cloud point (CP) as the threshold temperature of solubility the energetics of the solubilization (free energy, enthalpy and entropy) of the studied pure and mixed systems have been evaluated . An attempt has been made to evidence probable interaction between the surfactant and 'the polymers . .
Interfacial and bulk properties of sodium dodecyl sulfate (SDS), polyoxyethylene (20) sorbitan mo... more Interfacial and bulk properties of sodium dodecyl sulfate (SDS), polyoxyethylene (20) sorbitan monooleate (Tween-80), and their binary mixtures in aqueous medium have been investigated using surface tension, conductance, and fluorescence measurements at ...
ABSTRACT: The micellization of an anionic gemini surfactant, (CH2)2[N(COC11H23)CH(CO2H )CH2(CO2H)... more ABSTRACT: The micellization of an anionic gemini surfactant, (CH2)2[N(COC11H23)CH(CO2H )CH2(CO2H)]2·2NaOH, abbrevi-ated as GA, having N,N-dialkylamide, carboxyl, and carboxy-late groups, in aqueous solutions of NaCl at pH 5.0 was investi-gated by means ...
Journal of Photochemistry and Photobiology B: Biology, 2016
In aqueous solution, curcumin is photodegradable (light sensitive), it is also self-degradable in... more In aqueous solution, curcumin is photodegradable (light sensitive), it is also self-degradable in the dark. In basic medium, the second process is enhanced. The dark process has been studied in water and also in a number of protic and aprotic solvents, and aqueous solutions of ionic liquids, pluronics, reverse micelles and salt. The kinetics of the process followed the first order rate law; a comparative as well as individual assessment of which has been made. The kinetics of curcumin self-degradation has been found to be fairly dependent on salt (NaCl) concentration. Curcumin molecules in solution may remain in the enol or keto-enol form. From the visible spectral analysis, an estimate of the proportions of these forms in aqueous ethanol medium has been made. The temperature effect on the visible and fluorescence spectra of curcumin has been also studied. The steady state fluorescence anisotropy of the photoactive curcumin has been evaluated in different solvent and solution media. The reversibility of the steady state fluorescence anisotropy of curcumin on heating and cooling conditions has been examined. The results herein presented are new and ought to be useful as the study of physicochemistry of curcumin has been gaining importance in the light of its biological importance.
The interaction of a cationic dye crystal violet, in aqueous solution with different types of sur... more The interaction of a cationic dye crystal violet, in aqueous solution with different types of surfactants, such as anionic, cationic, non-ionic, gemini and their mixtures has been investigated spectrophotometrically and fluorimetrically in premicellar and post micellar concentration regions. In the premicellar concentration region of anionic surfactants, the dimer of the dye is formed; in the micellar concentration region, the monomer of the dye predominates. With cationic and nonionic surfactants, crystal violet is solubilised primarily as the monomer. In case of anionic and nonionic mixture, stability of dye–surfactant complex increases with increase in mole fraction of anionic surfactant. Cationic surfactant, cetyltrimethylammonium bromide (CTAB) has no interaction with crystal violet.► Spectroscopic method is studied for interaction between crystal violet and surfactant. ► CV is used first time for the interaction with gemini surfactants spectroscopically. ► Study of absorbance and fluorescence of CV is performed in several micellar systems. ► Cationic, anionic, nonionic, gemini surfactants are used for the interaction with CV. ► Mixtures of surfactants have also been used to study the interaction with CV.
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