Related Experiment Video
Updated: May 18, 2026
08:01
The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
Diffusion in a soft confining environment: dynamic effects of thermal fluctuations
Benoit Palmieri1, Samuel A Safran
1Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel.
Summary
Thermal fluctuations in a soft tube reduce diffusive transport rates. This study models how environmental dynamics impact particle movement within confined spaces, revealing key transport limitations.
Area of Science:
- Soft matter physics
- Transport phenomena
- Statistical mechanics
Background:
- Confined environments significantly influence particle transport.
- Thermal fluctuations can alter boundary conditions and affect diffusion.
- Understanding these effects is crucial for nanoscale transport applications.
Purpose of the Study:
- To investigate the impact of a confining environment's thermal fluctuations on diffusive transport within a soft tube.
- To model the dynamics of tube fluctuations driven by Brownian motion.
- To analyze how surface tension and environmental rigidity suppress these fluctuations.
Main Methods:
- Development of a dynamical model for a soft, thermally fluctuating two-dimensional tube.
- Incorporation of Brownian motion to drive tube fluctuations.
- Analysis of the modified concentration profile boundary condition at the tube surface.
Main Results:
- Dynamical fluctuations of the confining tube alter the surface concentration profile.
- Diffusive transport rates are decreased by tube fluctuations.
- This reduction occurs for uniform fluctuations (q=0) in finite tubes and for all fluctuations in infinite tubes.
Conclusions:
- Thermal fluctuations of the confining environment act as a barrier to diffusive transport.
- The study quantifies the reduction in transport rate due to these environmental dynamics.
- Findings are relevant for systems involving transport in fluctuating soft materials.
More Related Videos
05:56Spot Variation Fluorescence Correlation Spectroscopy for Analysis of Molecular Diffusion at the Plasma Membrane of Living Cells
Published on: November 12, 2020
15:10From Fast Fluorescence Imaging to Molecular Diffusion Law on Live Cell Membranes in a Commercial Microscope
Published on: October 9, 2014
Related Concept Videos
01:21Diffusion
Diffusion is a type of passive transport. In passive transport, a substance tends to move from an area of high concentration to an area of low concentration until the concentration is equal across the space. For example, take the diffusion of substances through the air. When someone opens a perfume bottle in a room filled with people, the perfume is at its highest concentration in the bottle and is at its lowest at the edges of the room. The perfume vapor will diffuse, or spread away, from the...
01:12Diffusion
Diffusion is the passive movement of substances down their concentration gradients—requiring no expenditure of cellular energy. Substances, such as molecules or ions, diffuse from an area of high concentration to an area of low concentration in the cytosol or across membranes. Eventually, the concentration will even out, with the substance moving randomly but causing no net change in concentration. Such a state is called dynamic equilibrium, which is essential for maintaining overall...
03:48Behavior of Gas Molecules: Molecular Diffusion, Mean Free Path, and Effusion
Although gaseous molecules travel at tremendous speeds (hundreds of meters per second), they collide with other gaseous molecules and travel in many different directions before reaching the desired target. At room temperature, a gaseous molecule will experience billions of collisions per second. The mean free path is the average distance a molecule travels between collisions. The mean free path increases with decreasing pressure; in general, the mean free path for a gaseous molecule will be...
01:24Protein Diffusion in the Membrane
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
01:21Carrier Transport
The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
01:17Passive Diffusion: Overview and Kinetics
Passive diffusion is a critical process that allows small lipophilic drugs to cross the cell membrane along a concentration gradient. This mechanism's efficiency depends on four primary factors: the membrane's surface area, the drug's lipid-water partition coefficient, the concentration gradient, and the membrane's thickness.
When administered orally, drugs establish a substantial concentration gradient between the gastrointestinal (GI) lumen and the bloodstream, expediting their diffusion into...
When administered orally, drugs establish a substantial concentration gradient between the gastrointestinal (GI) lumen and the bloodstream, expediting their diffusion into...