19 research outputs found
Contrasting effect of 1-butanol and 1,4-butanediol on the triggered micellar self-assemblies of type cationic surfactants
No full textClick on the DOI link to access the article (may not be free).The self-assembly in aqueous solutions of three quaternary salt-based -type cationic surfactants with different polar head groups and identical carbon alkyl chain viz., cetylpyridinium bromide (CPB), cetyltrimethylammonium tosylate (CTAT), and cetyltriphenylphosphonium bromide (CTPPB) in the presence of 1-butanol (BuOH) and 1,4-butanediol (BTD) was investigated using tensiometry, 2D-nuclear Overhauser enhancement spectroscopy (2D-NOESY) and small angle neutron scattering (SANS) techniques. The adsorption parameters and micellar characteristics evaluated at 303.15 K distinctly showed that BuOH promotes the mixed micelle formation while BTD interfered with the micellization phenomenon. The SANS data fitted using an ellipsoid (as derived by Hayter and Penfold using the Ornstein-Zernike equation and the mean spherical approximation) and wormlike micellar models offered an insight into the micelle size/shape and aggregation number in the examined systems. The evaluated descriptors presented a clear indication of the morphology transition in cationic micelles as induced by the addition of the two alcohols. We also offer an investigation into the acceptable molecular interactions governing the differences in micelle morphologies, using the non-invasive 2D-NOESY technique and molecular modeling. The experimental observations elucidated from computational simulation add novelty to this work. Giving an account to the structural complexity in the three cationic surfactants, the molecular dynamics (MD) simulation was performed for CPB micelles in an aqueous solution of alcohols that highlighted the micelle solvation and structural transition, which is further complemented in terms of critical packing parameter (PP) for the examined systems.V. K. acknowledges the Department of Chemistry, Sardar Vallabhbhai National Institute of Technology (SVNIT), Gujarat, for providing the instrumentation facility. The authors also sincerely acknowledge Dr Kulbir Singh, Department of Chemistry, StFX University, Antigonish, Nova Scotia, Canada for the spectral analysis. K. R. M. K. acknowledges support from the National Science Foundation under Grant No. CHE-1665157, the Wichita State University Department of Chemistry and Fairmount College of Liberal Arts and Sciences; computational resources funded by the National Science Foundation under Award no. EPS-0903806 and matching support from the State of Kansas through the Kansas Board of Regents; and the National Institute of General Medical Sciences (P20 GM103418) from the National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of General Medical Sciences or the National Institutes ..
Spectral and scattering microstructural investigation in cationic gemini surfactants (12-s-12) induced by p-toluidine
No full textSalt induced micellization conduct in PEO–PPO–PEO-based block copolymers: a thermo-responsive approach
No full textCTAB induced growth and shrinkage of Pluronics® P103 micelles: Experimental and theoretical rationale
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Synergism and aggregation behaviour in an aqueous binary mixture of cationic–zwitterionic surfactants: physico-chemical characterization with molecular simulation approach
No full textA physico-chemical characterization and molecular dynamics study of mixed surfactant systems in aqueous solution.</p
Micellization and clouding singularity amid the mixture of EO-PO-based star-block copolymer and cationic surfactants in aqueous solution
No full textAdditive-anchored thermoresponsive nanoscale self-assembly generation in normal and reverse Tetronics®
No full textSelf-assembly of ethylene oxide (EO)-propylene oxide (PO)-based star-shaped block copolymers (BCPs) in the presence of different kinds of additives is investigated in an aqueous solution environment. Commercially available four-armed BCPs, namely Tetronics® (normal: T904 with EO as the terminal end block; and reverse: T90R4 with PO as the terminal end block), each with 40%EO, are used. The effect of various additives such as electrolytes (NaCl and Na2SO4), nonelectrolyte polyols (glucose and sorbitol), and ionic surfactants (viz. anionic-sodium dodecyl sulfate (SDS), cationic-dodecyltrimethylammonium bromide (DTAB) and zwitterionic dodecyldimethylammonium propane sulfonate (C12PS)) on these BCPs is examined to observe their influence on micellization behaviour. The presence of salts and polyols displayed interesting phase behaviour, i.e., the cloud point (CP) was decreased, the water structure was affected and the micelles were dehydrated by expelling water molecules, and thus they were likely to promote micelle formation/growth. In contrast, ionic surfactants in small amounts interacted with the BCPs and showed an increase in CPs thereby forming mixed micelles with increasing charges and decreasing micellar sizes, finally transforming to small surfactant-rich mixed micelles. Molecular interactions such as electrostatic and hydrogen bonding involved within the examined entities are put forth employing a computational simulation approach using the Gaussian 09 window for calculation along with the GaussView 5.0.9 programming software using the (DFT)/B3LYP method and 3-21G basis set. The hydrodynamic diameter (Dh) of the micelles is examined using dynamic light scattering (DLS), while the various micellar parameters inferring the shape/geometry are obtained using small-angle neutron scattering (SANS) by the best fitting of the structure factors. It is observed that 10 w/v% T904 remains as spherical micelles with some micellar growth under physiological conditions (37 °C), while 10 w/v% T90R4 remains as unimers and forms spherical micelles in the presence of additives at 37 °C. Furthermore, the additive-induced micellar systems are tested as developing nanovehicles for anticancer (curcumin, Cur) drug solubilization using UV-vis spectroscopy, which shows a prominent increase in absorbance with enhanced solubilization capacity. Additionally, the cytotoxic effect of Cur loaded on the BCP micelles in HeLa cells is studied through confocal microscopy by capturing fluorescence images that depict HeLa cell growth inhibition under the influence of additive-induced micellar systems
Solubilization, micellar transition and biocidal assay of loaded antioxidants in Tetronic® 1304 micelles
No full textSelf-Association in EO–BO–EO Triblock Copolymers as a Nanocarrier Template for Sustainable Release of Anticancer Drugs
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