Watching RAFT PISA grow spheres, worms, vesicles
In situ SAXS shows PGMA45-PHPMA200 aqueous RAFT PISA nucleating in 9–10 min and finishing as ~227 nm vesicles.
Source
<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
Study at a glance
- Design
- Other — In situ SAXS of aqueous RAFT HPMA polymerization from a PGMA45 macro-CTA
- N
- ~2 mL SAXS cell polymerization tracking — no sample N
- Population
- Aqueous RAFT polymerization forming micelles, worms, and vesicles
- Outcome
- Time-resolved nucleation and morphological transitions during polymerization
Structured fields used in claim comparison tables when every cited study has a complete layer.
What they did
Authors polymerized HPMA from a PGMA45 macro-CTA at 70 °C in a ~2 mL SAXS cell and tracked scattering while checking conversion, GPC, DLS, and TEM after the run.
What they found
Micelles nucleate at 9–10 min; worms appear near PHPMA DP 134 after 28–29 min; vesicles reach Dv = 227 ± 16 nm. HPMA conversion exceeds 99% within 80 min; GPC Mn is 51 200 g mol−1 with Đ = 1.25.
The limits
What it doesn't show
The SAXS nucleation clock is faster than the lab 1H NMR rate jump; other PISA monomers and concentrations are not mapped at the same time resolution.
Key terms
- PISA
- Polymerization-induced self-assembly: a growing insoluble block triggers in situ nanoparticle formation.
- RAFT
- Reversible addition–fragmentation chain-transfer living radical polymerization.
- PGMA-PHPMA
- Glycerol monomethacrylate stabilizer with a 2-hydroxypropyl methacrylate core-forming block.
- SAXS
- Small-angle X-ray scattering used here in situ to assign spheres, worms, and vesicles.
- Jellyfish intermediate
- Transient branched-worm structure en route from worms to vesicles.
Flashcards
Research intelligence for this paper
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Quiz yourself
SAXS nucleation of micelles occurs at:
Common questions
When do micelles nucleate?
Within 9–10 minutes by SAXS intensity upturn.
When do worms start?
Near PHPMA DP 134, around 28–29 min.
Final vesicle size?
227 ± 16 nm by SAXS.
How complete is HPMA conversion?
More than 99% within 80 min at 70 °C.
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