New Approach to Encapsulation for Controlled Release of Chemical Additives

Abstract

A new approach for the synthesis of bio-inspired polymer microcapsules used to encapsulate chemical additives and designed for small molecule release and delivery is shown here. The flexibility to design different microcapsules using an emulsion template results in various encapsulated additives for a new polymer technology platform. The base materials for encapsulation are polyaramids that are highly crosslinked membrane shells around an empty core. These empty capsules provide a carefully designed space to site-isolate chemical additives, various encapsulants for encapsulation, and delivery where needed. These microcapsules have demonstrated that after being formed from a simple one-pot synthesis between two immiscible solutions, a new method for encapsulation for applications in ordinary Portland cement is possible. The final product is a free-flowing solid that can be easily added to any fluid application. Experimental results show that when added to a basic cement slurry design, cement responds to the release of a salt accelerant as measured using standard oilfield equipment, like the pressurized consistometer, which measures changes in viscosity and thickening times. In one of many applications, the consistency of cement remains favorable at 20 Bc after adding encapsulated calcium chloride for up to 5 hours, for example. Over time, various capsules caused cement slurries to set at right angles at various thickening times with the controlled release of encapsulated calcium chloride. This new approach for encapsulation is promising for the chemical and energy field.