Mean-field Ising crossover and the critical exponents γ, ν, and η for a polymer blend:d-PB/PS studied by small-angle neutron scattering

The critical behavior of the polymer blend d-PB/PS was investigated by small-angle neutron scattering experiments. 3D Ising behavior was clearly observed with the critical exponents {γ}=1.26±{}0.01, {ν}=0.59±{}0.01, and {η}=0.047±{}0.004. The crossover to mean-field behavior occurs at T*=Tc+5.4 K. This is compared with the results of other experiments and the Landau-Ginzburg criterion. The Q dependence of the structure factor S(Q) follows the Ornstein-Zernike form in both regimes.