Dependency of Anion and Chain Length of Imidazolium Based Ionic Liquid on Micellization of the Block Copolymer F127 in Aqueous Solution: An Experimental Deep Insight.

Jignesh Lunagariya,Abhishek Dhar,Rohit Vekariya,Nadavala Kumar,Mohammad Asif

doi:10.3390/polym9070285

Abstract

The non-ionic triblock copolymer, Pluronic® F127, has been selected to observe its interaction with ionic liquids (ILs) in aqueous solutions by using DLS, surface tension, and viscosity measurements. The Critical Micelle Concentration (CMC) of F127 increased with the addition of ILs, which appeared logical since it increases the solubility of PPO (and PEO) moiety, making it behaves more like a hydrophilic block copolymer that is micellized at a higher copolymer concentration. The results from DLS data showed good agreement with those obtained from the surface tension measurements. Upon the addition of ILs, the tendency in micellar size reduction was demonstrated by viscosity results, and therefore, intrinsic viscosity decreased compared to pure F127 in aqueous solution. The results were discussed as a function of alkyl chain length and anions of imidazolium based ILs.

Highlights

Interaction in aqueous solutions between Poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide), (PEO–PPO–PEO) like water soluble block copolymers and surfactants is very crucial in laundry detergents cosmetics, paint, coating, emulsification, and petroleum industries along with pharmaceutical interest [1,2]
We have reported the effect of ionic liquids (ILs) containing different chain lengths and anions on Micellization behavior of Pluronic® F127 block copolymer in aqueous media
Dynamic Light Scattering (DLS) measurements were performed on 5% (w/v) F127 solutions in water by varying the concentration of ionic liquids (ILs) at 30 ◦ C

Summary

Introduction

Interaction in aqueous solutions between Poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide), (PEO–PPO–PEO) like water soluble block copolymers and surfactants is very crucial in laundry detergents cosmetics, paint, coating, emulsification, and petroleum industries along with pharmaceutical interest [1,2]. As Pluronics® are often employed in complex environments, for instance, in presence of other additives or amphiphile, studies on their effect on solution behavior of copolymers can help to optimize properties based on performance for various applications. Additives such as electrolytes [13] and ionic liquids (ILs) [14,15]; non-electrolytes including urea [16], alkanols [17], and inorganic salts [18,19]; and surfactants [20] have been studied for their effect on the aggregation behavior of triblock copolymers. The addition of ethanol, for example, weakens the block segregation due to better solvency as compared to that of water [24]

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Results

Conclusion