MICELLES FORMED FROM PHOTOCHEMICALLY ACTIVE AMPHIPHILES - STRUCTURAL CHARACTERIZATION BY SMALL-ANGLE NEUTRON-SCATTERING

A novel class of photochemically active amphiphiles has been synthesiz ed containing a ketone moiety as a biradical or radical pair precursor on the hydrophobic tail of sodium sulfate surfactants. Alteration of the molecular structure of each ketone-containing surfactant allows fo r the systematic and predictable manipulation of the micellar size and shape, both of which are important in determining the coupling betwee n the unpaired electrons confined within the micelle and the intraradi cal dynamics. The structure of the resulting aggregates has been analy zed by small-angle neutron scattering (SANS). The results show that th e amphiphiles form ellipsoidal micelles with aggregation numbers betwe en 30 and 150 that depend on the balance between monomer dimensions an d steric effects caused by the atomic spatial arrangement within the h ydrophobic tail of the different surfactants.