Aging of colloidal gels in microgravity

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Datta, Swagata S., Paliwal, Waad, Weeks, Eric R.
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866908450242428928
author Datta, Swagata S.
Paliwal, Waad
Weeks, Eric R.
author_facet Datta, Swagata S.
Paliwal, Waad
Weeks, Eric R.
contents We study the aging of colloidal gels using light microscopy movies of depletion gels from the International Space Station. Under such microgravity conditions, we observe a slowdown in particle dynamics consistent with gel aging. Stronger attractive forces promote the formation of thicker gel strands over time. The samples are bidisperse, composed of particles with a size ratio 1.2. Larger particles experience stronger depletion forces, which lead to a large first-neighbor peak in the pair correlation function $g(r)$ due to the prevalence of large-large particle contacts. As the gel ages, small mobile particles are incorporated into the gel structure. The changes in gel structure correlate with a slow power-law decay in particle motion, observed over nearly two orders of magnitude of time scales in microgravity experiments. Additionally, through complementary ground-based experiments, we compare two-dimensional (2D) and three-dimensional (3D) images of depletion colloidal gels. While microgravity gel data are limited to 2D projections, ground-based data establish a correspondence between the 2D and 3D $g(r)$ peak heights. Our results provide new insights into how colloidal gels age in the absence of gravitational collapse.
format Preprint
id arxiv_https___arxiv_org_abs_2501_09650
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Aging of colloidal gels in microgravity
Datta, Swagata S.
Paliwal, Waad
Weeks, Eric R.
Soft Condensed Matter
Disordered Systems and Neural Networks
We study the aging of colloidal gels using light microscopy movies of depletion gels from the International Space Station. Under such microgravity conditions, we observe a slowdown in particle dynamics consistent with gel aging. Stronger attractive forces promote the formation of thicker gel strands over time. The samples are bidisperse, composed of particles with a size ratio 1.2. Larger particles experience stronger depletion forces, which lead to a large first-neighbor peak in the pair correlation function $g(r)$ due to the prevalence of large-large particle contacts. As the gel ages, small mobile particles are incorporated into the gel structure. The changes in gel structure correlate with a slow power-law decay in particle motion, observed over nearly two orders of magnitude of time scales in microgravity experiments. Additionally, through complementary ground-based experiments, we compare two-dimensional (2D) and three-dimensional (3D) images of depletion colloidal gels. While microgravity gel data are limited to 2D projections, ground-based data establish a correspondence between the 2D and 3D $g(r)$ peak heights. Our results provide new insights into how colloidal gels age in the absence of gravitational collapse.
title Aging of colloidal gels in microgravity
topic Soft Condensed Matter
Disordered Systems and Neural Networks
url https://arxiv.org/abs/2501.09650