Imbibition is a special type of

diffusion Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...

that takes place when liquid is absorbed by solids- colloids causing an increase in volume. Water surface potential movement takes place along a concentration gradient; some dry materials absorb water. A gradient between the absorbent and the liquid is essential for imbibition. For a substance to imbibe a liquid, there must first be some attraction between them. Imbibition occurs when a

wetting Wetting is the ability of a liquid to displace gas to maintain contact with a solid surface, resulting from intermolecular interactions when the two are brought together. These interactions occur in the presence of either a gaseous phase or ...

fluid displaces a non-wetting fluid, the opposite of drainage in which a non-wetting phase displaces the wetting fluid. The two processes are governed by different mechanisms. Imbibition is also a type of diffusion since water movement is along the concentration gradient. Seeds and other such materials have almost no water hence they absorb water easily. Water potential gradient between the absorbent and liquid imbibed is essential for imbibition.

Examples

One example of Imbibition in nature is the absorption of water by

hydrophilic A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press. In contrast, hydrophobes are n ...

colloids. Matrix potential contributes significantly to water in such substances. Dry seeds germinate in part by imbibition. Imbibition can also control circadian rhythms in ''

Arabidopsis thaliana ''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small plant from the mustard family (Brassicaceae), native to Eurasia and Africa. Commonly found along the shoulders of roads and in disturbed land, it is generally ...

'' and (probably) other plants. The Amott test employs imbibition. Proteins have high imbibition capacities, so proteinaceous pea seeds swell more than starchy wheat seeds. Imbibition of water increases imbibant volume, which results in imbibitional pressure (IP). The magnitude of such pressure can be demonstrated by the splitting of rocks by inserting dry wooden stalks in their crevices and soaking them in water, a technique used by early Egyptians to cleave stone blocks.

Skin graft Skin grafting, a type of graft (surgery), graft surgery, involves the organ transplant, transplantation of skin without a defined circulation. The transplanted biological tissue, tissue is called a skin graft. Surgeons may use skin grafting to ...

s (split thickness and full thickness) receive oxygenation and nutrition via imbibition, maintaining cellular viability until the processes of inosculation and revascularisation have re-established a new blood supply within these tissues.

Germination

Examples include the absorption of water by seeds and dry wood. If there is no pressure due to imbibition, seedlings would not be able to emerge from soil.

Radicle growth

The

radicle In botany, the radicle is the first part of a seedling (a growing plant embryo) to emerge from the seed during the process of germination. The radicle is the embryonic root of the plant, and grows downward in the soil (the shoot emerges from t ...

is the first part of a seedling (a growing plant

embryo An embryo ( ) is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sp ...

) to emerge from the

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

during the process of

germination Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ...

.{{cite journal , last1=Schiltz , first1=S , last2=Gaillard , first2=I , last3=Pawlicki-Jullian , first3=N , last4=Thiombiano , first4=B , last5=Mesnard , first5=F , last6=Gontier , first6=E , title=A review: what is the spermosphere and how can it be studied? , journal=Journal of Applied Microbiology , date=December 2015 , volume=119 , issue=6 , pages=1467–81 , doi=10.1111/jam.12946 , pmid=26332271, s2cid=42515027 , doi-access= The radicle is the embryonic

root In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...

of the plant, and grows downward in the soil (the shoot emerges from the plumule) where it absorbs more water. Most of the seed is stored energy so nutrients are not essential during the first days for the seedling.

References

Biological processes Chemical mixtures Colloidal chemistry

Examples

Germination

Radicle growth

See also

References