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 endash 4 wt%) and temperatures (295 endash 335 K) are interpreted in terms of simple models of fractal aggregates. The results show a large increase in dimensionality from ∼1 at ambient temperature 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. copyright 1996 The American Physical Society