Soft Matter at the Thermal Scale, Ch Polymer solutions and blends
Problem
A symmetric polymer blend has N=800 sites per chain for both components and χ=0.00625 (so χN=5.0). The binodal compositions satisfy ln[1−ϕϕ]=χN(2ϕ−1). Using bisection (or any equivalent root-finder) to a tolerance of 10−6 in ϕ, find the two binodal compositions, giving each to three significant figures.