Interaction between sodium dodecylsulfate (SDS) and pluronic L61 in aqueous medium: assessment of the nature and morphology of the formed mixed aggregates by NMR, EPR, SANS and FF-TEM measurements. Issue 23 (3rd June 2021)

• Record Type: Journal Article
• Authors: Prameela, G. K. S.; Phani Kumar, B. V. N.; Subramanian, J.; Tsuchiya, K.; Pan, A.; Aswal, V. K.; Abe, M.; Mandal, A. B.; Moulik, S. P.
• Is Part Of: Physical chemistry chemical physics. Volume 23:Issue 23(2021)
• Page Start: 13170
• Page End: 13180
• Publication Date: 2021-06-03
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d0cp06227h
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The gist of the morphological changes of the self-assemblies in solution by way of the SDS–L61 interaction primarily based on findings from SANS and FFTEM measurements supplemented with other methods. Abstract : The interaction of copolymer L61 i.e., (EO)2 (PO)32 (EO)2 (where EO and PO are ethylene and propylene oxides, respectively) with surfactant SDS (sodium dodecylsulfate) in relation to their self-aggregation, dynamics and microstructures has been physicochemically studied in detail employing the Nuclear Magnetic Resonance (NMR), Electron Paramagnetic Resonance (EPR), Small-Angle Neutron Scattering (SANS), and Freeze-Fracture Transmission Electron Microscopy (FF-TEM) methods. The NMR self-diffusion study indicated a synergistic interaction between SDS and L61 forming L61–SDS mixed complex aggregates, and deuterium ( 2 H) NMR pointed out the nonspherical nature of these aggregates with increasing [L61]. EPR spectral analysis of the motional parameters of 5-doxyl steraric acid (5-DSA) as a spin probe provided information on the microviscosity of the local environment of the L61–SDS complex aggregates. SANS probed the geometrical aspects of the SDS–L61 assemblies as a function of both [L61] and [SDS]. Progressive evolution of the mixed-aggregate geometries from globular to prolate ellipsoids with axial ratios ranging from 2 to 10 with increasing [L61] was found. Such morphological changes were further corroborated with the results of 2 H NMR and FF-TEM measurements. The strategy of the measurements, and data analysis for a concerted conclusion have been presented.