Inside-Out, Dual Light-, and pH-Triggered Release from Oil-Core Microcapsules Via CATCH Cleavage Mechanism

The facile degradation of encapsulants is a challenging problem especially when it involves microcapsules in the solid state. In this report we utilize the CATCH cleavage concept to induce inside-out degradation of acid-degradable, poly(hydroxy urethane) microcapsules. The capsules are fabricated using interfacial polymerization with trimesoyl chloride and a hydroxy acetal bearing diamine that can undergo degradation under anhydrous conditions. We demonstrate that by encapsulating a photoacid generator as a trigger, we can increase the internal local acid concentration and degrade the microcapsules with UV light (365 nm) photolysis. This novel microcapsule degradation, with shell cleavage from acid generated from within the core, should enable new opportunities and future applications.