pH Responsiveness of Polyelectrolyte Dendrimers: A Dynamical Perspective

Abstract

Quasielastic neutron scattering (QENS) experiments were carried out to investigate the internal dynamics of aqueous (D2O) G5 PAMAM dendrimer solutions as a function of molecular protonation at room temperature. The localized motion was clearly exhibited in data analysis by being separated from the global translational diffusion. Our results unambiguously point out that with the molecular charge increased continuously the local motion is stably enhanced. The charge-induced local dynamics of dendrimer segments may correspond to their interaction with the surrounding counterions and water molecules. The outcome may provide significant information for the application of dendrimer-based packages as drug delivery vehicles.