What is Imbibition?

Imbibition is a type of diffusion where the water is absorbed by the solid particles called colloids, without forming a solution causing an enormous increase in volume. To define, the absorption of water by hydrophilic colloids is known as imbibition.


Process of Imbibition

Imbibants are the solid substance or adsorbent which take part in imbibition and the liquid that is imbibed is known as imbibate. For example, the absorption of water by seed or dry wood.

The capacity of imbibing will differ in different imbibants. For instance consider proteins, since it is a hydrophilic collides it will have maximum imbibing capacity. Compared to this, starch has less capacity and cellulose with least capacity.

Features of Imbibition

The important characteristics of imbibition are:

Water Potential

The water potential of an imbibant is negative. Water has the highest water potential (0).

Increase in Volume

During imbibition, the volume of the imbibant increases. For eg., swelling of the soaked seeds, swelling of wooden frames during rains.

Water Potential Gradient

When a dry imbibant comes in contact with water, a steep water potential gradient is created. Water diffuses from the higher potential into the imbibant.

Heat of Wetting

Heat energy is released during imbibition. This is known as the heat of wetting.


The imbibant holds the imbibate by adsorption. It is an attractive force between two substances.

Also Read: Adsorption vs Absorption

Factors Affecting Imbibition

Various factors affecting imbibition include:

  • pressure
  • pH of a medium
  • the texture of an imbibant
  • the affinity of the imbibant for the imbibate.

Condition Necessary for Imbibition

There are three conditions that are necessary for imbibition:

  • A water potential gradient should occur between imbibant and liquid imbibe.
  • There should be some force of attraction between imbibant and imbibed liquid.
  • Increase in temperature brings about increased imbibition.

Imbibition In Plants

  • Imbibition causes swelling of seeds and results in the breaking of testa.
  • Imbibition is the initial step in seed germination.
  • The water moves into ovules which are ripening into seeds by imbibition.
  • Imbibition is dominant in the initial stage of water absorption by roots.

Imbibition Pressure

This pressure can be of tremendous magnitude and can be demonstrated by a technique that is used by early Egyptians. That is split a rock and insert a wooden stalk that is completely dry in the crevices of the rocks and soak them in water. It was used to cleave stone blocks.

Different types of organic substances have different imbibing capacities. Proteins have a very high imbibing capacity than starchless and cellulose least. That is why proteinaceous pea seeds swell more on imbibition than starchy wheat seeds.

Significance of Imbibition

The significance of imbibition includes:

  1. It is the first step of water absorption.
  2. It is the first in seed germination.
  3. It keeps the cells moist.

Difference Between Imbibition and Diffusion

The important difference between imbibition and diffusion is mentioned below:

Imbibition Diffusion
It refers to the absorption of water by general surface. It refers to the movement of molecules, ions of solids, liquids or gases from the region of higher concentration to lower concentration
It takes place both in living and dead cells. It takes place in solids, liquids and gases.
It is a reversible process. It is not a reversible process.
An absorbent is involved but no there is membrane. No need of semi-permeable membrane.

Also Read: Difference between diffusion and osmosis

For more information on Imbibition, the difference between imbibition and diffusion and imbibition in plants, keep visiting BYJU’S website or download BYJU’S app for further reference.

Frequently Asked Questions

What is Imbibition?

Imbibition is the process of water adsorption by substances without forming a solution. For eg., swelling of seeds immersed in water.

What is the difference between imbibition and osmosis?

Imbibition is the process of water absorption through a solid substance, whereas, osmosis is the process of movement of water from higher concentration to lower concentration through a semi-permeable membrane.

How is imbibition important?

Imbibition is the first step of water absorption. It helps in the germination of seeds and facilitates absorption of water by the roots of the plants. The seedlings emerge out of the soil and establish themselves through imbibition.

How is imbibition different from diffusion?

Imbibition is a reversible process whereas diffusion is an irreversible process. Imbibition is the absorption of water by general surface whereas diffusion is the movement of solid, liquid or gaseous molecules from the region of higher concentration to lower concentration.

Give a few examples of imbibition.

The swelling of soaked seeds, the swelling of a wooden door during rains, germination of seeds, absorption of water by roots are some of the examples of imbibition.


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