Microstructure and rheological properties of ferrocene modied branched poly(ethylene imine)(Fc-BPEI) in aqueous solutions were investigated through dynamic light scattering

transmission electron microscopy (TEM) and rheometry.The influences of shear

concentration and temperature on microstructure and rheological behavior of Fc-BPEI aqueous solutions were also explored.Compared with pure BPEI

the molecule size of Fc-BPEI obviously increases.It is found that the dominate association in aqueous solutions transfers from intramolecular to intermolecular association with the increase of concentration and intermolecular associations are formed

inducing a considerable increase in viscosity of Fc-BPEI aqueous solutions.However

these Fc-BPEI aqueous solutions represent a typical rheological behavior of Newtonian fluid.After undergoing continuous heating-cooling treatments

the viscosities of Fc-BPEI aqueous solutions increase significantly.Furthermore

the increment of viscosity gradually decreases as the heating-cooling treatment repeats.The dynamic rheological results indicate that heating-cooling treatment could lead to the changes in macromolecular association and resulting microstructure of polymers.Some Fc-BPEI macromolecules could simultaneously participate in multiple intermolecular association structures and consequently a large structure of macroscopic network-like forms.Fc-BPEI aqueous solutions present obvious shear-thinning due to the occurrence of associative network after thermal treatments and anti-shear ability of high concentration solutions of Fc-BPEI remarkably improves.