Destruction of chitosan capsules based on host–guest interaction and controllable release of encapsulated dyes

This article describes a new and simple method to control the release of payloads encapsulated in chitosan capsules. The capsules with the liquid core and rigid shell are performed by drop-wisely adding chitosan solution into anionic surfactant solution. The capsules can be destroyed by β-CD because β-CD binds and sequesters surfactant from the shell through the host-guest interaction. The destruction process is studied by optical microscopy and scanning electron microscopy. The capsules can swell in acid solution and shrink in alkaline solution. It is found that the destruction speed increases with increasing acidity or alkalinity of β-CD solution. Rhodamine B encapsulated in the liquid-core of chitosan capsules can be released from the capsules in β-CD solution. The release rate can be adjusted by the pH value of β-CD solution. The release speed of the capsule increases with the increase of acidity or alkalinity in β-CD solution. The above concept can provide more versatility for controlled release of a variety of payloads such as drugs, cosmetics, and so on. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45229.