Poly(styrene-alt-maleimide) (SMI) is a cationic polyelectrolyte soluble in acidic solution, having a pH<3.  This alternating copolymer is expected to self-assemble in similar structures as SMA, which Cecile Malardier worked on.  SMI was shown to self-associates into ordered nano-structures and were characterized by AFM of dilute solutions (< 1%).  At pH 1-2, ring shaped structures, diameter of 70nm and height 15nm were observed, while at pH 3, linear structures with random curves and bifurcations were observed: 1nm long and 10nm high.  Molecular Modelling helps understand the self-assembly of these polymers and predict the dimensions of the nanostructures.