A SAXS study of the internal structure of dendritic polymer systems
β Scribed by Ty J. Prosa; Barry J. Bauer; Eric J. Amis; Donald A. Tomalia; Rolf Scherrenberg
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 312 KB
- Volume
- 35
- Category
- Article
- ISSN
- 0887-6266
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β¦ Synopsis
Small-angle x-ray scattering was used to characterize the single-particle scattering factors produced by poly(amidoamine) dendrimers, poly(propleneimine) dendrimers, and polyol hyperbranched polymers in dilute solutions with methanol as solvent. Fits from electron density modeling reveal similar overall densities of the dendrimers as a function of dendrimer generation. The seventh through tenth generation poly(amidoamine) dendrimers exhibit higher order scattering features that require nearly monodisperse, spherical particles with essentially uniform internal segment densities. Dilute hyperbranched polymer solutions exhibit scattering more indicative of the inherent irregularity of internal segment densities and overall sizes to be expected within these systems. Radii of gyration estimated from electron density modeling agree reasonably well with those estimated by standard Guinier methods used in previous studies.
π SIMILAR VOLUMES
The thermodynamic-equilibrium structures of four copolymers with different chain architectures are compared. They are AB diblock, BAB triblock, and ABC triblock copolymers and AB 2 star-branched graft copolymers. Their morphological transitions meaningfully differ from one another, reflecting the di