<i>In situ</i> SAXS studies of a prototypical RAFT aqueous dispersion polymerization formulation: monitoring the evolution in copolymer morphology during polymerization-induced self-assembly
Adam Czajka, Steven P. Armes
Abstract
H NMR spectroscopy indicates more than 99% HPMA conversion within 80 min, while transmission electron microscopy and dynamic light scattering studies are consistent with the final morphology being pure vesicles. Analysis of time-resolved SAXS patterns for this prototypical polymerization-induced self-assembly (PISA) formulation enables the evolution in copolymer morphology, particle diameter, mean aggregation number, solvent volume fraction, surface density of copolymer chains and their mean inter-chain separation distance at the nanoparticle surface to be monitored. Furthermore, the change in vesicle diameter and membrane thickness during the final stages of polymerization supports an 'inward growth' mechanism.
Topics & Concepts
CopolymerRaftDispersion polymerizationSmall-angle X-ray scatteringPolymerizationMaterials scienceReversible addition−fragmentation chain-transfer polymerizationMorphology (biology)Self-assemblyPolymer chemistryAqueous solutionDispersion (optics)In situChemical engineeringRadical polymerizationNanotechnologyChemistryPolymerOrganic chemistryComposite materialScatteringPhysicsBiologyOpticsEngineeringGeneticsAdvanced Polymer Synthesis and CharacterizationPolymer Surface Interaction StudiesRadioactive element chemistry and processing