From single molecules to aggregates to gels in dilute solution: Self-organization of nanoscale rodlike molecules

A study of transition from a fluid to a constrained phase, in dilute solutions of rodlike molecule, poly(2,5-dinonylparaphenylene ethynylene)s (PPE) in toluene was done. It was indicated by the nuclear magnetic resonance relaxation measurements that significant restriction of motion of the solvent and of the polymeric molecule took place as the gel like phase was formed. The aggregation of PPE molecules into large flat clusters occurred upon transition into the constrained phase.