Preparation method of hard shell calcium alginate oil capsule

Abstract

The invention provides a preparation method of a hard-shell calcium alginate oil sac. The method comprises the following steps: a. preparing emulsion: stirring soluble alginate, liquid oil and deionized water at high speed so as to form the uniform emulsion; b. molding a wet oil sac: dropwise adding the emulsion, obtained in the step a, into a soluble calcium salt solution, and stirring for carrying out reaction to obtain the wet oil sac which takes calcium alginate gel as a shell; c. dehydrating: filtering out the wet oil sac obtained in the step b, and then drying to constant weight so as to obtain the hard-shell calcium alginate oil sac. The oil sac prepared by the method is molded at a time, and the preparation technology is simple; the prepared hard-shell calcium alginate oil sac is controllable in size and uniform in shape; the raw materials used by the preparation method do not need to be specially processed, and the emulsion for preparing the oil sac is formed by directly carrying out high-speed mechanical agitation on the raw materials, so that the use of chemicals such as an emulsifying agent and a surface active agent is avoided, the after-treatment process is simplified, and the after-treatment cost is lowered; the preparation method is easy in raw material obtaining, simple in device, convenient to operate and low in cost, thus being suitable for being widely used.

Description

technical field [0001] The invention relates to a preparation method of an oil capsule used for self-repairing of asphalt materials in road engineering, in particular to a preparation method of a hard-shell calcium alginate oil capsule. Background technique [0002] Alginic acid is a natural biopolysaccharide extracted from brown algae or bacteria. Due to its excellent and mild sol-gel process and low production cost, alginate is suitable as a capsule for embedding or releasing drugs, so it has been widely used in the fields of chemistry, biology, medicine, food and so on. However, there are few reports on the use of alginate as a capsule wall material to prepare oil-carrying capsules as a self-repairing material for asphalt materials in the field of road engineering. [0003] The existing capsule preparation methods are relatively cumbersome. For example, the preparation methods disclosed in Chinese patents CN103041397A and CN103006616A are to first prepare the mixed glue ...

AI Technical Summary

Problems solved by technology

However, there are few reports on the use of alginate as a capsule wall material to prepare oil-carrying capsules as a self-repairing material for asphalt materials in the field of road engineering.

[0003] The existing capsule preparation methods are relatively cumbersome. For example, the preparation methods disclosed in Chinese patents CN103041397A and CN103006616A are to first prepare the mixed glue and then dip the glue in the mold to form it, and then go through the steps of pulling out the shell, cutting, and reassembling to finally form a capsule. This kind of capsule requires secondary molding and the process is cumbersome, which is not conducive to mass production

Most other methods use emulsifiers to make emulsion particles. For example, Chinese patent CN104906049A uses emulsifiers mixed with solvents to form a continuous phase, and then passes through a microfluidic device together with sodium alginate solution (discrete phase) and calcium chloride solution (solidified liquid). The reaction was carried out to prepare sodium alginate microspheres. This kind of capsule uses a surfactant to simplify the early oil-water mixing, but it is not good for the oil-water separation after the capsule is formed, and it is not easy to form an oil capsule shell with good mechanical strength. Irrelevant substances, increasing the cost of preparation