SURFACE FRACTALS IN BLOCK-COPOLYMERS

A surface fractal model was presented to describe the interface in blo ck copolymers. It gives a simple power-law relationship between the sc attering intensity I(q) and the wave vector q in a relatively wide ran ge as qxi >> 1, I(q) is-proportional-to q(D-6), where xi is the length characterizing the size of the structure producing scattering, D is t he fractal dimension of the interface. Small-angle X-ray scattering ex periment results of both linear and star styrene-butadiene-styrene tri block copolymers show that the model is quite reasonable. It seems tha t the interface constructed by the joints of different blocks is a fra ctal surface with a fractal dimension D from 2 to 3.