Recent work involving temperature-triggered association and gel formation within aqueous solutions of a new family of cationic poly(N-isopropyl acrylamide) (PNIPAm) graft copolymers is presented. Five copolymers were synthesized using aqueous atom transfer radical polymerisation (ATRP) involving a macroinitiator based on quaternarized N,N-dimethylaminoethyl methacrylate units (DMA⁺). The copolymer solutions showed temperature-triggered formation of nanometer-sized aggregates at the cloud point temperature, which was 33 – 34 ^oC. The aggregates were investigated using variable temperature turbidity, hydrodynamic diameter and electrophoretic mobility measurements. The aggregates were clearly evident using SEM and flower-like morphologies were observed (Fig. 1). Variable-temperature electrophoretic mobility measurements revealed that the zeta potentials of the aggregates increased with DMA⁺ content. A study of the effect of added NaNO₃ showed that electrostatic interactions controlled the size of the aggregates. The concentrated graft copolymer solutions showed temperature-triggered gelation (Fig. 2) when the copolymer concentrations exceeded 5 wt.% It was found that electrostatic interactions also controlled the gelation temperature. A correlation was found between aggregate size and the minimum copolymer concentration needed to form a gel. A mechanism for the temperature-triggered structural changes leading to the formation of aggregates (in dilute solution) or gels (in concentrated solutions) is presented.