Othon Moultos
PI at Delft University of Technology
Research Interests
Explore related searches
Contact this professor
Articles (18)
Ultrasound enhanced diffusion in hydrogels: An experimental and non-equilibrium molecular dynamics study
Focused ultrasound has experimentally been found to enhance the diffusion of nanoparticles; our aim with this work is to study this effect closer using both experiments and non-equilibrium molecular dynamics. Measurements from single particle tracking of 40 nm polystyrene nanoparticles in an agarose hydrogel with and without focused ultrasound are presented and compared with a previous experimental study using 100 nm polystyrene nanoparticles. In both cases, we observed an increase in the mean square displacement during focused ultrasound treatment. We developed a coarse-grained non-equilibrium molecular dynamics model with an implicit solvent to investigate the increase in the mean square displacement and its frequency and amplitude dependencies. This model consists of polymer fibers and two sizes of nanoparticles, and the effect of the focused ultrasound was modeled as an external oscillating force field. A comparison between the simulation and experimental results shows similar mean square displacement trends, suggesting that the particle velocity is a significant contributor to the observed ultrasound-enhanced mean square displacement. The resulting diffusion coefficients from the model are compared to the diffusion equation for a two-time continuous time random walk. The model is found to have the same frequency dependency. At lower particle velocity amplitude values, the model has a quadratic relation with the particle velocity amplitude as described by the two-time continuous time random walk derived diffusion equation, but at higher amplitudes, the model deviates, and its diffusion coefficient reaches the non-hindered diffusion coefficient. This observation suggests that at higher ultrasound intensities in hydrogels, the non-hindered diffusion coefficient can be used.
Year:
2024
Collaborators (12)
Carlos Vega
Full Professor
Universidad Complutense de Madrid
Hadi Hajibeygi
Associate Professor
TU Delft
Mahinder Ramdin
Delft University of Technology
Erika Eiser
Professor
-
Romain PRIVAT
Université de Lorraine
Jean‐Noël Jaubert
Université de Lorraine
Anders Lervik
-
Costas Vlahos
University of Ioannina
Poulumi Dey
-
Johan Padding
Prof. at Delft University of Technology
Delft University of Technology
Silvia Lasala
Assistant professor
-
Thijs J. H. Vlugt
Delft University of Technology

How do I reach out?
Sign in for free to see their profile details and contact information.