Diffusion

Diffusion is the movement of molecules from an area of ​​higher concentration to an area of ​​lower concentration as a result of their thermal movement.

This process occurs in gases, liquids and solids. For example, if in a closed vessel there is an area with a higher concentration of gas molecules and an area with a lower one, then over time the concentration will equalize due to diffusion.

Molecules move chaotically, collide with each other and change direction. So they are gradually mixed and distributed evenly throughout the entire volume. The rate of diffusion depends on temperature, molecular size, and viscosity of the medium.

Diffusion plays an important role in many physical, chemical and biological processes. For example, the diffusion of oxygen in the lungs, the diffusion of nutrients in cells, the spread of odors and other phenomena are based on this process. Understanding diffusion mechanisms is important for science and technology.

Diffusion is the process of spreading a substance from an area of ​​high concentration to an area of ​​low concentration. This process occurs due to the movement of molecules of a substance across boundaries between areas of different concentrations.

Diffusion can occur in a variety of systems, including gases, liquids and solids. In gases, diffusion occurs quickly due to the high mobility of molecules, in liquids it occurs more slowly due to the lower mobility of molecules and the presence of intermolecular forces. In solids, diffusion practically does not occur, since the molecules are in a crystal lattice and cannot move freely.

One example of diffusion is the spread of odor in the air. When you inhale the scent of a perfume, the scent molecules travel through the air and reach your nose. This diffusion process occurs because perfume molecules have more mass and energy than air molecules, and therefore they can move through the air.

In addition, diffusion plays an important role in biological systems. For example, in the blood, diffusion of nutrients and oxygen occurs through the walls of capillaries. This allows the necessary substances to be delivered to the cells of the body.

In general, diffusion is an important process in nature and technology. It allows substances and energy to move through various environments and ensure exchange between them.

Introduction Diffusion is the process of spreading particles of one substance inside another. Occurs under the influence of thermal movement of particles and differences in substance concentrations. As a result of diffusion, new mixtures are formed.

The concept of diffusion Diffusion is characterized by a displacement of the interfaces between contacting substances. It is of great importance for many technological processes in various fields of technology: cement production, oil and petroleum products refining, metal smelting, glass melting, etc.

Types of diffusion processes Stationary diffusion. It is determined by the ratio of the rates of concentration accumulation processes and the movement of diffusants. Equilibrium diffusion is a type of diffusion process in which equilibrium concentrations of diffusing components are gradually established. Nonequilibrium - observed when equilibrium values ​​of the concentrations of the components do not have time to establish. Physical (volumetric) diffusion occurs during the mixing of layered materials. Collective is a type of diffusion in which the movement of atoms occurs in a layer with a width commensurate with the size of atoms or molecules. Basic is the phenomenon of the transfer of molecules or ions through membranes that are enormous in size compared to the size of the particles of the transported substance and which are impermeable to these particles. Relaxation diffusion is the most general type of diffusion and is characterized by transfer realized due to concentration fluctuations. Spatial diffusion manifests itself in chemical compounds in the presence of stationary charges. For polymer diffusion, it is necessary to take into account the interaction of side chains. Molecular diffusion is characteristic of dilute solutions. Chemisorption. Decrease in the surface concentration of adsorbed molecules. The adsorbate displaces the adsorbent from the active layer. Polytherm of differential adsorption. As is known, the rate of diffusion depends on the nature of the substances between which diffusion transfer occurs, their concentration and temperature, therefore the diagram or isotherm must be stripes.