Ask for help on how to prepare microcapsules

I did it with in-situ polymerization, which was filtered through filter paper, and it was difficult to get a single microcapsule! A single layer of microcapsules can be obtained by applying drying to a glass sheet. In the preparation, if the adhesive wall can be screened to solve the problem!!

Preparation method and principle of microcapsule The traditional preparation method of microcapsule can be roughly divided into three categories: physical method, physical and chemical method, and chemical method.

The physical method is the preparation of microcapsules by physical and mechanical methods, and its pioneer is the United States.

At the end of the 40s of the last century, he first prepared microcapsules using the air suspension method.

The methods for the preparation of microcapsules include physical methods and chemical methods.

1. Physical methods can be called mechanical methods, including spray drying, spray coating, extrusion technology, etc.

2. Chemical methods include composite coagulation, composite precipitation, in-situ polymerization, etc.

3. In addition, there are other methods such as nanoparticle process, molecular microencapsulation (cyclodextrin), phase transition materials, etc.

After microencapsulation treatment, the color, shape, volume, mass, solubility and storage of the core material with special characteristics will undergo certain changes, and under certain conditions, the core material will be slowly released to play a role.

The shapes of microcapsules are different, mainly irregular type, simple type, multi-core type, multi-wall type, filler particle type, etc.; According to the functional characteristics, it includes sustained-release type, pressure-sensitive type, heat-sensitive type, light-sensitive type, expansion type, pH value sensitive type, etc.

The complex coagulation method is a method for preparing microcapsules, which can prepare microcapsules with controlled-release properties, and are often used in the preparation of drugs, cosmetics and other fields.

If the prepared microcapsules are to be made into a solution, it is generally necessary to break or rupture the microcapsules to release the substances inside them and mix them evenly with the solvent. Here's how:

Break the microcapsules: The microcapsules can be added to a mortar, ground with the mortar to break them up to form particles, and then add them to the solvent and stir well.

Method: Add the microcapsule to a centrifuge tube, add an appropriate amount of solvent, and then use the microcapsule to carry out, after a period of time, the microcapsule in the centrifuge tube will rupture, and the solution will contain the substances in the microcapsule.

Ultrasonic method: The microcapsules are added to an ultrasonic water bath, an appropriate amount of solvent is added, and then treated with an ultrasonic water bath, which will produce a high frequency **, which will rupture the microcapsules and release the substance. After a period of treatment, the solution contains the substances in the microcapsules.

The above three methods can prepare the microcapsule lead bucket into a solution, and the specific method can be selected according to the actual situation. Attention should be paid to protecting one's own safety during operation, and appropriate measures should be taken to avoid pollution to the surrounding environment when the microcapsule is ruptured and guessed.

In the process of preparing microcapsules, stirring is always accompanied, but the stirring speed is to minimize the foam generation, and a few drops of pentanol or octanol are added to defoam if necessary to improve the yield.

There are many preparation methods for microcapsules, which can be divided into physicochemical, chemical and physicomechanical. The appropriate preparation method can be selected according to the content of the capsule, the nature of the capsule, the equipment and the size of the microcapsule. In the laboratory, the coagulation method of physical and chemical methods is often used for the preparation of microcapsules.

The coagulation method is further divided into single coagulation method and complex coagulation method. The latter often uses gelatin and gum arabic as capsule materials.

In order to make the shape of microcapsules good and the yield high, it is necessary to master the process of preparing microcapsules by complex coagulation method and the factors affecting the formation of microcapsules. Through experiments, the principle of preparation of microcapsules by complex coagulation method was further understood.

Microcapsules (microcapsules) are microcapsules that use natural and semi-synthetic polymer materials (commonly known as capsule materials) to encapsulate solid or liquid drugs (commonly known as capsules). Its diameter is generally 5 400 m.

The cross-linking agent formaldehyde should be added quickly at one time, because the curing of microcapsules is to cross-link the capsule materials through the reaction of formaldehyde with the cyst-forming material, so as to form a stable capsule shell. Since the initial capsule material is not cross-linked, the rapid addition of formaldehyde can make the reaction more carried out inside the milk droplets, and reduce the mutual reaction between the milk droplets, thereby reducing the cross-linking, and making the solidified microcapsule particles more uniform.

In order to make the shape of microcapsules good and the yield high, it is necessary to master the industrial and elimination techniques of preparing microcapsules by complex coagulation method and the factors affecting the formation of microcapsules. Through experiments, the principle of preparation of microcapsules by complex coagulation method was further understood.

Microcapsules (microcapsules) are microcapsules made by using natural and semi-synthetic polymer materials (commonly known as capsule materials) to wrap solid or liquid drugs (commonly known as capsule) around the head of the bridge. Its diameter is generally 5 400 m.

Physical Law. Spray drying method, spray freezing method, air suspension method, vacuum evaporation deposition method, complex coagulation method, multi-space centrifugation method.

Physicochemical method.

Aqueous phase separation method, oil phase separation method, capsule core exchange method, extrusion method, sharp hole method, powder bed method.

Chemical method. Interfacial polybiblic method In-situ polymerization method Molecular encapsulation method Radiation encapsulation method a-dispersion of the inner phase in the medium; b- Add film-forming materials (wall materials) with caution;

c- Deposition of wall materials; D- Curing of the wall film.

Application of SPG film emulsification method in microcapsules.

SPG membrane emulsifier is mainly used to prepare emulsions, milk beads, microspheres, microcapsules, etc. of uniform size, and can prepare different emulsions of W O, O W, W O W, O W O types. Dimensional uniformity and controllability of emulsions can be achieved; controllability and stability of functional groups on the surface of the microspheres; controllability and stability of porous microsphere structure; feasibility of large-scale preparation of homogeneous emulsions; controllability of porous microspheres or extended-release capsule pores, etc.

1 100um controllable size.

The application of microencapsulation technology in the food industry is as follows: Manufacture of solid beverages.

a. Formula. 160g of gum arabic, 70g of edible titanium dioxide, 182g of edible gelatin, 300g of white dextrin, 182g of orange oil flavor, 57g of carotene, 380g of citric acid, 45g of sodium citrate, 36g of benzoic acid, 30g of white sugar, appropriate amount of water.

b. Process flow.

white sugar—>; Smash.

Raw materials — >; emulsification — >; Mixed — >; granulation—>; Drying—>; Cooling — >; Molding—>; Inspection—>; Packaging—>; Factory.

Additive microencapsulation technology can be applied to the coloring, flavoring, and flavoring of candy, as well as the nutritional enhancement and quality improvement of candy. Natural food colorings, flavors, nutritional enhancers and other substances in candy production are easy to decompose, and they are microencapsulated by spray drying and other methods to ensure the stability of product quality.

Commonly used wall materials include water-soluble edible gum, cyclodextrin, cellulose derivatives, gelatin, casein and other substances, and the candy produced by this method is bright and long-lasting, and the product has a long shelf life. Acidulants:

The wallcovering used as a microencapsulated acidulant is generally hydrogenated oil, and the heartwood is released with the help of heat and water. Specifically, it includes acidulants for meat products, dough quality improvers (mainly ascorbic acid), and acidulants for other purposes such as phosphoric acid.

Flavors & Seasonings:

This aspect is the most widely used area of microencapsulation technology in the food industry. The most common ones are: lemon oil, peppermint oil, garlic oil, curry oil, etc.

Sweeteners: such as aspartame.

Pigments: Some natural pigments have poor solubility and stability problems in the application, and microencapsulation can not only change the solubility but also improve its stability.

Microencapsulation is a technology in which trace substances are encapsulated in polymer films, and is a micro-packaging technology that stores solids, liquids, and gases.