Partitioning of small amphiphiles at surfactant bilayer/water interfaces: an avoided level crossing muon spin resonance study.
The temperature-dependent variation of local environment and reorientation dynamics of the small amphiphile 2-phenylethanol in lamellar phase dispersions of the dichain cationic surfactants, 2,3-diheptadecyl ester ethoxypropyl-1,1,1-trimethylammonium chloride (DHTAC) and dioctadecyldimethylammonium chloride (DODMAC), and the nonionic surfactant, tetra(ethylene glycol) n-dodecyl ether (C12E4), have been determined using avoided level crossing muon spin resonance spectroscopy (ALC-muSR). For cosurfactant radicals the hydrophobic or hydrophilic character of the surrounding media can be determined from their magnetic resonance signatures. Comparison of the three different bilayer-forming surfactant systems shows that the ALC-muSR technique is able to distinguish both major and subtle differences in the partitioning of the cosurfactant radicals between the different systems.
Scheuermann
Robert
R
Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen, Switzerland.
Tucker
Ian M
IM
Dilger
Herbert
H
Staples
Ed J
EJ
Ford
Gary
G
Fraser
Stuart B
SB
Beck
Bettina
B
Roduner
Emil
E
D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005609:Free Radicals / Q000737:chemistry; D008567:Membranes, Artificial; D008651:Mesons; D015394:Molecular Structure; D010626:Phenylethyl Alcohol / Q000737:chemistry*; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
D005609:Free Radicals; D008567:Membranes, Artificial; D013501:Surface-Active Agents; D014867:Water; D010626:Phenylethyl Alcohol