Properties of Colloidal Dispersions
- Due to the presence of a dispersed phase and dispersion medium in colloidal solutions, they are heterogeneous in nature.
- The colloidal solution seems to be homogeneous because the particles are not visible.
- Colloidal solution particles flow through filter paper readily but are held by animal membranes, ultrafilters, and cellophane.
- Lyophilic and lyophobic sols are both highly stable in the absence of significant concentrations.
- The color of the color solution is determined by the particle size. The longer wavelength light will be absorbed by the bigger particle, whereas the shorter wavelength light will be absorbed by the smaller particle.
Optical Properties
Tyndal effect
When a light beam is sent through a colloidal solution that has been maintained in the dark, the path of the beam is lit with blue light. Tyndall cone is the result of the Tyndall effect, whereas the effect itself is called Tyndall effect. A colloidal solution causes the Tyndall effect by scattering light by particles.Brownian movement
- Brownian Movement is a term used to describe a group of
- In colloidal solutions, Brownian movement is characterized by zigzag movements of the particles in the dispersion medium.
- Brownian movement is created by moving molecules in the dispersion medium bombarding colloidal particles unevenly.
- Brownian movement reduces as the size of the colloidal particles grows larger. As a result, there is no Brownian movement in the suspension.
Kinetic properties
Brownian movement
Brownian motion colloidal dispersion is made up of particles that move in zigzag patterns. Brownian movement occurs as a result of the uneven bombardment of colloidal particles by moving molecules of dispersion media. Size has a direct relationship with the mobility of colloidal particles.Electrical properties
Electrical double-layer theory
The particles are charged in this theory by depositing ions at immovable sites in the first layer. The second layer contains diffused mobile ions. The charge on both of these levels is the same. The development of a potential known as the Electrokinetic potential arises from this two-layer structure. They move under the influence of electric fields due to the growth of the potential around these particles.Electrophoresis
In this process, an electric field is applied to a colloidal fluid, allowing colloidal particles to move. The charge of the particles can be determined by observing the buildup near the electrodes. If the particles are gathered near a positive electrode, their charge is negative, and vice versa.Electro-osmosis
It is a method of stopping particles in a colloidal solution by exposing the dispersion medium to an electrical field.Surface charge
The surface charge on the dispersed phase is relevant in the following:- Colloids' physical stability the stronger the electrostatic repulsion between dispersed-phase particles, the greater the physical separation and uniformity of the colloidal dispersion. The cake generated, however, may not be easily re-dispersible once it has settled. As a consequence, an electrostatic charge balance on the particles is sought, which promotes uniform dispersion formation and also allows for simple re-dispersibility after settling.
- An aggregation of submicron particles or a particle's affinity for a filtering membrane can lower the efficacy of submicron particle filtration.
- Polymers, polyelectrolytes, proteins, etc., are affected by interactions with solvents and intramolecular interactions inside polymers.
Uses
- Crystalloids and colloids are fluids that are utilized in medicine to replace fluids.
- In medicine, colloidal gold can be utilized to deliver antibiotics and medicines.
- Insoluble compounds like metallic gold and lipids can be dispersed using colloidal particles. They are easier to absorb and use.
- Milk's colloidal fat dispersion prevents it from becoming thick and enables for simple nutritional absorption.
- In order to prepare the roadways, asphalt emulsified in water is employed.
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