with F(q) being the form factor as described in Eq 1-3 and the 1/q 2 the Lorentz correction applied for planar structures. While the thin membrane electron density profile appears unchanged with increasing PBd22-PEO14 mole fraction, the peak positions and trough depth increase with increasing PBd22-PEO14 mole fraction in the thick membrane model. Figure shows that initially the minima in the thick membrane electron density profiles have a similar depth to the thin membrane models (Figure ).