Wax-protected catalyst microspheres for efficient self-healing materials

Microspheres of wax containing embedded Grubbs' catalyst are generated by congealing a molten aqueous suspension. Even with a ten-fold reduction in catalyst concentration from previous systems, these microspheres produce unprecedented levels of toughness recovery in a polymeric self-healing material (see Figure). Unlike the previously reported systems, samples healed with the wax microspheres show nonlinear fracture behavior. A protocol that addresses this nonlinearity is employed to measure healing efficiency.