Thermostimulable Wax@SiO2 Core-Shell Particles

We propose a new synthesis pathway without any sacrificial template to prepare original monodisperse thermo-7 responsive capsules made of a wax core surrounded by a silica shell. Under heating, the inner wax expands and the shell 8 breaks, leading to the liquid oil release. Such capsules that allow triggered deliverance provoked by an external stimulus 9 belong to the class of smart materials. The process is based on the elaboration of size-controlled emulsions stabilized by 10 particles (Pickering emulsions) exploiting the limited coalescence phenomenon. Then the emulsions are cooled down 11 and the obtained suspensions are mineralized by the hydrolysis and condensation of a monomer at the wax-water 12 interface, leading to the formation of capsules. The shell break and the liquid oil release are provoked by heating above 13 the wax melting temperature. We characterize the obtained materials and examine the effect of processing parameters 14 and heating history. By an appropriate choice of the wax, the temperature of release can easily be tuned