title: Partitioning of 2-phenylethanol and limonene cosurfactants in C12E4.
abstract: Avoided level-crossing muon spin resonance (ALC-μSR) has been used to study the dynamics and local environment of spin probes formed by muonium (Mu) addition to 2-phenylethanol (PEA) and limonene (1-methyl-4-(1-methylethenyl)-cyclohexene) in an aqueous dispersion of the nonionic surfactant C12E4(tetra(ethylene glycol) n-dodecyl ether). The spin probes derived from both cosurfactants reside within the micelles in the L1phase and the bilayers in the Lαphase rather than in the aqueous region. The local polarity measured by the different isomers of the Mu adducts of PEA suggests there is a water gradient within the micelles and bilayers. Slow rotation of the micelles broadened the Δ1resonances with increasing temperature in the L1phase while narrower Δ1resonances were observed in the Lαphase due to the rapid rotation of the spin probes around a preferred axis, which was wobbling within a cone.
authors.affiliation: Centre for Molecular and Materials Science, TRIUMF, Vancouver, BC, Canada. iain.mckenzie@triumf.ca and Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada.
authors.forename: Iain
authors.identifier: http://orcid.org/0000-0002-0588-3952
authors.initials: I
authors.lastname: McKenzie
authors.affiliation: Laboratory for Muon Spectroscopy, Paul Scherrer Institute, Villigen AG, Switzerland.
authors.forename: Robert
authors.initials: R
authors.lastname: Scheuermann
authors.affiliation: Unilever Research and Development, Port Sunlight, Wirral, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Tucker