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Characterization of Dendritically Branched Polymers by SANS, SAXS, and TEM

Published

Author(s)

Barry J. Bauer, Eric J. Amis

Abstract

Small angle neutron scattering (SANS), small angle x-ray scattering (SAXS), and transmission electron microscopy (TEM) have been used to characterize the size, shape and interactions of dendrimers, hyperbranched, and dendrigraft polymers. Size in terms of radius of gyration (Rg) from scattering and diameter from microscopy can be routinely measured. Five technologically important factors of dendritically branched polymers have been identified and measured. Dendrimers have a uniform spherical structure without a greatly depressed segment density distribution (SDD) at the center or a broad outer interfacial transition. Dendrimers are spheres with a uniform SDD and an abrupt outer transition, hyperbranched are polydisperse and have Gaussian SDD, dendrigraft have a uniform interior with a star-like outer transition. The terminal units of dendrimers are predominately on the exterior of the molecule. Dendrimers at high concentrations tend to align and will shrink rather than interpenetrate at high concentration. There is negligible size change of dendrimers in solvents of different quality or when charged.
Citation
Dendritic polymers

Keywords

dendrigraft, dendrimer, hyperbranched, SANS, SAXS, segment density distribution, TEM

Citation

Bauer, B. and Amis, E. (2008), Characterization of Dendritically Branched Polymers by SANS, SAXS, and TEM, Dendritic polymers (Accessed May 20, 2024)

Issues

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Created October 16, 2008