How soft repulsion enhances the depletion mechanism

Autor(en)

Lorenzo Rovigatti, Nicoletta Gnan, Alberto Parola, Emanuela Zaccarelli

Abstrakt

We investigate binary mixtures of large colloids interacting through soft potentials with small, ideal depletants. We show that softness has a dramatic effect on the resulting colloid-colloid effective potential when the depletant-to-colloid size ratio q is small, with significant consequences on the colloidal phase behaviour. We provide an exact relationship that allows us to obtain the effective pair potential for any type of colloid-depletant interaction in the case of ideal depletants, without having to rely on complicated and expensive full-mixture simulations. We also show that soft repulsion among depletants further enhances the tendency of colloids to aggregate. Our theoretical and numerical results demonstrate that - in the limit of small q - soft mixtures cannot be mapped onto hard systems and hence soft depletion is not a mere extension of the widely used Asakura-Oosawa potential.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

Università degli Studi di Roma La Sapienza, Consiglio Nazionale delle Ricerche, Università degli Studi dell'Insubria

Journal

Soft Matter

Band

11

Seiten

692-700

Anzahl der Seiten

9

ISSN

1744-683X

DOI

https://doi.org/10.1039/c4sm02218a

Publikationsdatum

01-2015

Peer-reviewed

Ja

ÖFOS 2012

103023 Polymerphysik, 103018 Materialphysik, 103029 Statistische Physik

Schlagwörter

ASJC Scopus Sachgebiete

Condensed Matter Physics, Allgemeine Chemie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/147fa0ce-2c49-4ec2-bd4d-37c014e32d47