The process of microencapsulation technology

　　The microencapsulation process can be divided into four core steps, encompassing various preparation methods such as complex coacervation, interfacial polymerization, and spray drying. Different methods vary in material selection, polymerization methods, and application scenarios.

　　Core Steps (Based on Microcapsule Granulation Process):

　　Disperse Core Material: Uniformly disperse the core material (solid, liquid, or gas) in a medium.

　　Introduce Wall Material: Add the polymeric wall material to the system, forming the basis for encapsulating the core material.

　　Encapsulation and Shaping: Use physical or chemical methods (such as temperature changes, pH adjustment, polymerization reactions) to cause the wall material to aggregate and encapsulate the core material.

　　Curing: Enhance the mechanical stability of the microcapsules through heating, crosslinking, or solvent removal.

　　Main Preparation Methods:

　　Complex Coacervation:

　　Utilizes two polymers with opposite charges (such as gelatin and gum arabic) that crosslink through electrostatic interaction, depositing around the core material to form microcapsules.

　　Suitable for water-soluble core materials, widely used in pharmaceuticals and food.

　　Interfacial Polymerization:

　　Two monomers are dissolved in water and an organic solvent respectively, and a polymerization reaction occurs at the interface of the core material droplets to form a wall membrane.

　　Suitable for encapsulating liquid core materials; the microcapsule structure is dense.

　　Spray Drying:

　　Atomize a mixture of core material and wall material, and quickly dry it with hot air to form microcapsule particles.

　　Low cost and easy to industrialize; often used for fragrance and oil encapsulation.

　　Sharp-Hole - Solidification Bath Method:

　　Drop a mixture of core material and wall material into a solidifying agent (such as calcium chloride solution), and the wall material quickly solidifies to form microcapsules.

　　Simple operation, suitable for low-temperature embedding.

　　Fluidized Bed Coating Method:

　　Suspended solid core materials in a fluidized bed, spraying a wall material solution to form a coating.

　　Suitable for solid particles, such as drug sustained-release preparations.

　　The choice of method depends on the nature of the core material (water-soluble/oil-soluble), wall material compatibility, and target application (sustained release, protection of active ingredients, etc.). For example, water-soluble core materials require oil-soluble wall materials to avoid chemical reactions.