Recently flexible polymer solutions have been interpreted as a manifestation of critical phenomena in the vicinity of a second-order transition point. The change from critical to mean-field behavior in polymer solutions at a given temperature or a given concentration is observable by small-angle neutron scattering. This technique allows direct examination of the q dependence of the scattering law S(q) in the intermediate range defined by 1/RG < q < 1/l, where q is the momentum transfer vector |q| = q = 4π/λ sin θ/2 (λ neutron wavelength, θ scattering angle), RG is the radius of gyration of a chain and l the step length. The analysis of S(q) shows that this function is not uniform but displays a spatial cross-over. This observation agrees with the prediction of a new characteristic length ξ which varies with temperature and concentration.
No takes yet. Share an insight, caveat, or question.
Farnoux et al. (1978) studied this question.