Structure and interaction of flexible dendrimers in concentrated solution

TL;DR

This study investigates how mutual interactions affect the conformation of flexible dendrimers in concentrated solutions using small-angle neutron scattering, revealing shape stability despite concentration changes.

Contribution

It provides detailed insights into the conformation and interaction effects of flexible dendrimers at concentrations near the overlap threshold.

Findings

Dendrimers maintain shape across concentrations.

Interaction effects are characterized by partial structure factors.

Conformational stability contrasts with flexible linear polymers.

Abstract

We study the influence of mutual interaction on the conformation of flexible poly(propyleneamine) dendrimers of fourth generation in concentrated solution. Mixtures of dendrimers with protonated and deuterated end groups are investigated by small-angle neutron scattering up to volume fractions of 0.23. This value is in the range of the overlap concentration of the dendrimers. The contrast between the solute and the solvent was varied by using mixtures of protonated and deuterated solvents. This allows us to investigate the partial structure factors of the deuterated dendrimers in detail. An analysis of the measured scattering intensities reveals that the shape of the flexible dendrimers is practically independent of the concentration in contrast to the pronounced conformational changes of flexible linear polymers.