title: Physicochemical perspectives (aggregation, structure and dynamics) of interaction between pluronic (L31) and surfactant (SDS).
abstract: The influence of the water soluble non-ionic tri-block copolymer PEO-PPO-PEO [poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)] i.e., E2P16E2 (L31) on the microstructure and self-aggregation dynamics of the anionic surfactant sodium dodecylsulfate (SDS) in aqueous solution was investigated using cloud point (CP), isothermal titration calorimetry (ITC), high resolution nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and small-angle neutron scattering (SANS) measurements. CP provided the thermodynamic information on the Gibbs free energy, enthalpy, entropy and heat capacity changes pertaining to the phase separation of the system at elevated temperature. The ITC and NMR self-diffusion measurements helped to understand the nature of the binding isotherms of SDS in the presence of L31 in terms of the formation of mixed aggregates and free SDS micelles in solution. EPR analysis provided the micro-viscosity of the spin probe 5-DSA in terms of rotational correlation time. The SANS study indicated the presence of prolate ellipsoidal mixed aggregates, whose size increased with the increasing addition of L31. At a large [L31], SANS also revealed the progressive decreasing size of the ellipsoidal mixed aggregates of SDS-L31 into nearly globular forms with the increasing SDS addition. Wrapping of the spherical SDS micelles by L31 was also corroborated from (13)C NMR and SANS measurements.
authors.affiliation: Chemical Physics Laboratory and Chemical Laboratory, CSIR - Central Leather Research Institute, Adayar, Chennai-600020, India. abmandal@hotmail.com abmandal@clri.res.in.
authors.forename: G K S
authors.initials: GK
authors.lastname: Prameela
authors.affiliation: Chemical Physics Laboratory and Chemical Laboratory, CSIR - Central Leather Research Institute, Adayar, Chennai-600020, India. abmandal@hotmail.com abmandal@clri.res.in.
authors.forename: B V N
authors.initials: BV
authors.lastname: Phani Kumar
authors.affiliation: Centre for Surface Science, Department of Chemistry, Jadavpur University, Kolkata 700032, India. spmcss@yahoo.com.
authors.forename: A
authors.initials: A
authors.lastname: Pan
authors.affiliation: Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, India. vkaswal@barc.gov.in.
authors.forename: V K
authors.initials: VK
authors.lastname: Aswal
authors.affiliation: Chemical Physics Laboratory and Chemical Laboratory, CSIR - Central Leather Research Institute, Adayar, Chennai-600020, India. abmandal@hotmail.com abmandal@clri.res.in.
authors.forename: J
authors.initials: J
authors.lastname: Subramanian
authors.affiliation: Chemical Physics Laboratory and Chemical Laboratory, CSIR - Central Leather Research Institute, Adayar, Chennai-600020, India. abmandal@hotmail.com abmandal@clri.res.in.
authors.forename: A B
authors.initials: AB
authors.lastname: Mandal
authors.affiliation: Centre for Surface Science, Department of Chemistry, Jadavpur University, Kolkata 700032, India. spmcss@yahoo.com.
authors.forename: S P
authors.initials: SP
authors.lastname: Moulik
mesh_terms: D002627:Chemistry, Physical; D015394:Molecular Structure; D011092:Polyethylene Glycols / Q000737:chemistry*; D011409:Propylene Glycols / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: C116176:PEO-PPO-PEO; D011409:Propylene Glycols; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate; D011092:Polyethylene Glycols