Structure and interaction of flexible dendrimers in concentrated solution

摘要

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 protonatedand deuterated end groups are investigated by small-angle neutron scattering up to volume fractionsof 0.23. This value is in the range of the overlap concentration of the dendrimers. The contrastbetween the solute and the solvent was varied by using mixtures of protonated and deuteratedsolvents. This allows us to investigate the partial structure factors of the deuterated dendrimers indetail. An analysis of the measured scattering intensities reveals that the shape of the flexibledendrimers is practically independent of the concentration in contrast to the pronouncedconformational changes in flexible linear polymers.