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Presentation On. Wetting Agents and Solubiliging Agents. Wetting Agents. Definition:

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  1. Presentation On Wetting Agents andSolubiliging Agents www.AssignmentPoint.com

  2. Wetting Agents Definition: • Wetting agents are substances that reduce the surface tension of water to allow it to spread drops onto a surface, increasing the spreading abilities of a liquid. Lowering the surface tension lowers the energy required to spread drops onto a film, thus weakening the cohesive properties of the liquid and strengthening its adhesive properties. One example of how wetting agents work is in the formation of micelles. Micelles consist of hydrophilic heads forming an outer layer around lipophilic tails. When in water, the micelles' tails can surround an oil droplet while the heads are attracted to the water. www.AssignmentPoint.com

  3. Figure 1: An example diagram of a micelle. The green heads are hydrophilic and are thus attracted to water. The brown tails are lipophilic and thus attracted to fats and oils. www.AssignmentPoint.com

  4. Types of Wetting Agents There are four main types of wetting agents: anionic, cationic, amphoteric, and nonionic. • Anionic, cationic, and amphoteric wetting agents ionize when mixed with water. • Anions have a negative charge, while cations have a positive charge. • Amphoteric wetting agents can act as either anions or cations, depending on the acidity of the solution. • Nonionic wetting agents do not ionize in water. A possible advantage for using a nonionic wetting agent is that it does not react with other ions in the water, which could lead to formation of a precipitate. www.AssignmentPoint.com

  5. How to Tell if a Liquid Contains a Wetting Agent By two methods - • One method of knowing whether or not a liquid has a wetting agent in it is to spread the liquid on a surface that is coated in grease. If the liquid does not contain a wetting agent, the its cohesive forces would overpower adhesive forces, causing the liquid to for droplets on the surface. If the liquid does contain a wetting agent, the grease would be dissolved and the surface tension of the liquid would be lowered, causing the adhesive forces to overpower the cohesive forces. This would result in the liquid spreading evenly along the surface. www.AssignmentPoint.com

  6. Another method is to place the liquid in a test tube and observe the liquid's meniscus. If the liquid contains a wetting agent, its adhesive forces are stronger than cohesive forces, which means the liquid molecules are more inclined to stick to the surface than other liquid molecules. This results in a concave meniscus. If the liquid does not contain a wetting agent and is naturally very cohesive, like mercury, it forms a convex meniscus. This is caused by the fact the the molecules of the liquid have a stronger attraction to each other than to the surface of the test tube. www.AssignmentPoint.com

  7. Uses for Wetting Agents: • Detergents • Fabric softener • Paints • Inks • Anti-fogging • Soil remediation • Ski wax • Snowboard wax • Foaming agents • Laxatives • Agrochemical formulations • Shampoo www.AssignmentPoint.com

  8. Solubilization • It is a short form for micellarsolubilization, a term used in colloidal and surface chemistry. Solublization may occur in a system consisting of a solvent, an association colloid (i.e., a colloid that forms micelles), and at least one other component called the solubilizate (i.e., the component that undergoes solublization).Solubilization is the process of incorporation of the solubilizate into or onto the micelles. www.AssignmentPoint.com

  9. Application • Micellar solublization is widely utilized, e.g. in: • laundry washing using detergents, • In pharmaceutical industry, for formulations of poorly soluble drugs in solution form • In cleanup of oil spills using dispersants. www.AssignmentPoint.com

  10. Mechanism • Literature distinguishes two major mechanisms of solubilization process of oil by surfactant micelles, affecting the kinetics of solubilization: • Surface reaction, i.e., by transient adsorption of micelles at the water-oil interface, and • Bulk reaction, whereby the surfactant micelles capture dissolved oil molecules. www.AssignmentPoint.com

  11. THANKS TO ALL..... www.AssignmentPoint.com

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