Probing the Microenvironment of Unimicelles Constituted of Amphiphilic hyperbranched Polyethyleneimine using 1-methyl-8-oxyquinolinium Betaine

PICCO, A.S.; SILBESTRI, G.F.; FALCONE, R.D.; AZZARONI, O.; CEOLÍN, M.; CORREA, N.M.

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2014 vol. 16 p. 13458 - 13464

1463-9076

In this work, the microenvironment of the core of different unimicelles of hyperbranched polyethyleneimine HPEI) capped with different aliphatic chains (stearate, palmitate, and laurate) dissolved in toluene has been investigated. To achieve this goal we have used 1-methyl-8-oxyquinolinium betaine (QB) as a molecular probe due to its solvatochromic behavior to monitor the micropolarity and hydrogen bond donor ability of the unimicelle cores. QB shows that the micropolarity and the hydrogen bond donor capability of the polar core of reverse unimicellar media are very different than toluene and similar to the one obtained with traditional surfactants that form reverse micellar media but at a very low unimicelle concentration. Particularly, our results show that the hydrogen bonding ability of the core is the driving force for QB to partition toward the unimicellar media.