Fluorosurfactants at structural extremes: adsorption and aggregation.
Fluorosurfactants with several structural modifications have been synthesized, and the air/water interface and bulk aggregation properties investigated. The compounds were fluorinated ethylene oxide (EO) nonionics where the number and position of the hydrophilic group(s) has been radically altered to generate linear, bolaform, and Y-shaped analogues. A noticeable structure-interfacial packing relationship was observed via both tensiometric measurements and neutron reflection studies: the limiting molecular areas, a(cmc), and surface excesses, gamma(cmc), are strongly dependent on the number and position of the EO headgroups. Differing bulk aqueous properties were also observed. Small-angle neutron scattering shows an evolution of micelle structure from cylindrical to disk-like aggregates on changing from Y-shaped to bolaform molecular structure.
School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK. julian.eastoe@bristol.ac.uk
Julian
J
Eastoe
Sarah E
SE
Rogers
Laura J
LJ
Martin
Alison
A
Paul
Frédéric
F
Guittard
Elisabeth
E
Guittard
Richard K
RK
Heenan
John R P
JR
Webster