Leiden University Student Repository

Douwes, Mirte (2024)

Depletion interaction in flexible colloidal structures

Bachelor thesis | Natuurkunde (BSc)

Depletion force induces the flocculation of colloidal particles, providing a means to influence the stable states of colloidal structures. By determining the depletion force across various sizes and concentrations of depletants, we identified the optimal size and concentration range for effective depletion forces. Our results highlight the existence of an optimal depletant size. Steric interactions obstruct the proximity of colloids, hindering small depletants from creating depletion force. On the other side of the spectrum, larger polymers either adhere to colloidal surfaces \cite{Kuhl1996} or generate a lower depletion force due to their lower number density. Nevertheless, the force magnitude remains significant. The advantage of larger depletants, is that they offer a larger interaction range, enabling the formation of colloidal hysterons. All polymers measured create sporadically strong attractive interactions between colloids, creating unpredictability in the control of...Show moreDepletion force induces the flocculation of colloidal particles, providing a means to influence the stable states of colloidal structures. By determining the depletion force across various sizes and concentrations of depletants, we identified the optimal size and concentration range for effective depletion forces. Our results highlight the existence of an optimal depletant size. Steric interactions obstruct the proximity of colloids, hindering small depletants from creating depletion force. On the other side of the spectrum, larger polymers either adhere to colloidal surfaces \cite{Kuhl1996} or generate a lower depletion force due to their lower number density. Nevertheless, the force magnitude remains significant. The advantage of larger depletants, is that they offer a larger interaction range, enabling the formation of colloidal hysterons. All polymers measured create sporadically strong attractive interactions between colloids, creating unpredictability in the control of colloidal structures.Show less

Author

Douwes, Mirte

Faculty

Faculty of Science

Supervisors

Kraft, D.J.

ECTS Credits

24

Language

en