Effect of n-Hexanol and n-Hexylamine on the Micellar Solutions of Pluronic F127 and P123 in Water and 1M NaCl

The micelles from aqueous solution of two ethylene oxide(EO)-propylene oxide(PO) triblock copolymers, Pluronic P123 [(EO)20(PO)69(EO)20] and F127 [(EO)99(PO)69(EO)99], with identical PPO but different PEO in the presence of n-hexylamine and n-hexanol were examined using viscosity and dynamic light scattering (DLS) measurements. Micelles of more hydrophilic F127 did not show any noticeable growth or transition in the presence of n-hexylamine in water or in 1M NaCl solutions, while those of P123 showed significant growth after a certain hexylamine concentration, with the effect being more pronounced in salt solutions. Similar behavior was observed in the presence of n-hexanol, which showed greater effect in comparison to n-hexylamine. The effect of n-hexylamine on F127 has been examined using small-angle neutron scattering (SANS) method also, which showed good agreement with viscosity and DLS results. n-Hexylamine and n-hexanol affect the micellar environment in different ways as per their individual solubility rankings.