Fractal scaling of small-angle neutron scattering from nonionic micellar solutions below the cloud temperature

Power-law variations of small-angle neutron-scattering intensities from nonionic micellar solutions of isooctylphenoxy polyethoxy ethanol (Triton X-100) in D2O for a range of concentrations (1-4 wt %) and temperatures (295-335 K) are interpreted in terms of simple models of fractal aggregates. The results show a large increase in dimensionality from similar to 1 at ambient temperature to similar to 2.3 near the cloud points. The variation of. fractal dimension with temperature is almost the same for the three concentrations studied. Thus one arrives at a picture of micellar aggregates becoming more and more tenuous as cloud points are approached.