| abstract |
An abrupt pressure change applied to a dispersion of core and shell material in a liquid carrier medium encapsulates the core material within the shell material. The method and apparatus of this invention permit a wider range of core and shell materials to be utilized than was possible with prior art methods including materials which previously have not been usable as shell materials. Materials in solid, liquid, gas or multiphase form may be encapsulated. Additionally, capsules are produced in a small fraction of the time required by prior art methods. The total time to perform the encapsulation may range from a few seconds to only a few minutes. The abrupt pressure change may be applied to the dispersion by either a piston or ultrasonic apparatus in both batch, semi-continuous, and continuous processes. Recycling of the capsules through the apparatuses permits adjustment of the capsules' characteristics as well as formation of multiple core capsules. |