State-of-the-Art Review on the Characteristics of Surfactants and Foam from Foam Concrete Perspective

Detergent Plants of Northern Thailand: Potential Sources of Natural Saponins

“…A surfactant is a substance which reduces the surface tension of water and the interfacial tension between oil and water [13,14]. Structurally, surfactants contain both hydrophobic and hydrophilic groups called amphipathic molecules [14][15][16][17][18][19][20]. The hydrocarbon chain interacts weakly with the water molecules in an aqueous environment, whereas the polar or ionic head group interacts strongly with water molecules via dipole or ion-diploe interactions.…”

“…It is this powerful interaction with the water molecules that makes surfactants soluble in water [15]. Owing to their unique characteristics, surfactants can self-assemble spontaneously in solutions with various morphologies within spherical micellar structures [16] or gather at the interface to reduce the interfacial tension [14,19]. Due to the behaviour of surfactants, they are widely applicable in chemical industries as wetting, flocculating, and foaming agents, adhesives, cleansing agents, and emulsifiers [13][14][15]20].…”

“…Soap is a type of surfactant that is generally used for cleansing purposes. For this reason, many plants used for cleaning are called soapbark, soapwort, soapnut, soaproot, and soapberry [14,21].…”

“…Surfactants can be classified based on where they were obtained: natural and synthetic [14]. The surfactants obtained directly from natural sources are considered natural surfactants.…”

“…Many plant products are bio-based surfactants. They produce the compounds known as glycosidically-derivative saponins [14], the best-known plant-based surfactants [13]. Plant-derived saponins have gained increasing attention due to their excellent functional properties, health benefits, and being environmentally safe.…”