Characterization of triblock copolymer E67S15E67–surfactant interactions

Characterization of Surfactant-Diblock Copolymer Interactions and Its Thermodynamic Studies

“…Water soluble copolymers, in combination with ionic surfactants are used in many applications and in different processes (e.g., pharmaceutical, industrial foaming, drug solubilization, oil recovery, and as medium for metal nanoparticle formation). [1] The binding interaction between anionic surfactant and uncharged polymer is much larger than interaction between uncharged polymer and nonionic or cationic surfactant. [2] In recent years, nonionic block copolymers with both hydrophilic and hydrophobic block have been focused.…”

pH Sensitive Polymer Nanoparticles: Effect of Hydrophobicity on Self-Assembly

“…Such finding raises many questions about the importance of the forces which are usually regarded as minor compared to electrostatic ones for the formation of the complex. The vast majority of complexes reported in literature so far are formed between a polyelectrolyte and an ionic surfactant. − Meanwhile, there is also proof that complexation can occur between a neutral polymer and an ionic surfactant ,− or vice versa, − or even, though very rarely, when both components are neutral . Thus, for deeper understanding of the mechanisms involved in complex formation, other interactions must be taken into consideration.…”

Aggregation of Ionic Surfactants to Block Copolymer Assemblies: A Simple Fluorescence Spectral Study

“…These systems are also fascinating to study in view of their complex ways of association into nanoscale self-assembled structures. Several methods such as calorimetry, electromotive force measurement, nuclear magnetic resonance (NMR), and scattering techniques such as light, X-ray (SAXS), and neutron (SANS) have been employed to investigate their aggregation and to assess the performance and compatibility of surfactant mixtures for potential applications. − Though the information obtained from all these methods is unparallel, they involve complex data analysis and interpretation procedures and are also time-consuming. Moreover, due to the complexity of these systems only semiquantitative or qualitative information could be drawn from the above-mentioned experimental techniques, and a comprehensive picture for the aggregation mechanism is yet to emerge.…”

“…It is established that ionic surfactants bind cooperatively with both copolymer monomers and micelles. − At low ionic surfactant to copolymer mole ratios ( n ), copolymer−surfactant complexes are basically copolymer-rich micelles with few surfactant molecules, and at high n values, copolymer-rich micelles are destroyed and surfactant-rich micelles with free copolymer monomers are formed. − However, there is ambiguity regarding the transformation of dominantly copolymer-rich complex to mainly surfactant-rich complex in the intermediate n region (∼2−9). ,,,, Either it is a gradual incorporation of surfactants into the copolymer micelles with release of copolymer units until surfactant-rich micelles are formed (type I) or there is simultaneous buildup of surfactant- rich micelles together with the destruction of copolymer-rich micelles (type II). Scheme depicts a qualitative picture of a possible aggregation mechanism for copolymer assemblies with ionic surfactants.…”