Highly efficient photothermal conversion capric acid phase change microcapsule: Silicon carbide modified melamine urea formaldehyde.

The microcapsule containing phase change materials(microPCMs) with high efficiency of photothermal conversion was prepared by in-situ polymerization via ultrasonic dispersion which used capric acid(CA) as core material and nano silicon carbide(nano-SiC) modified melamine-urea-formaldehyde(MUF) resin as wall material. The nano-SiC has good cross-linking with MUF shell. When the nano-SiC was added in microPCMs, it behaves superior thermal conductivity and thermal storage properties. When the content of nano-SiC arrives 6 wt%, the performance of the microPCMs whose encapsulation efficiency is 65.7% is the best, and thermal conductivity increase by 59.2%. Due to the proper amount of nano-SiC added into the MUF shell, it can effectively fill the tiny holes on the MUF shell. Therefore, the microPCMs with appropriate nano-SiC have better leakage prevention. It is worth noting that MicroPCMs-6% and MicroPCMs-8% show excellent photothermal conversion property, and the photothermal conversion rate is 74.4% and 71.1% respectively in the photothermal conversion experiment. Because nano-SiC can effectively capture and absorb photons under light irradiation and convert light into heat through internal molecular vibration, the microPCMs with appropriate nano-SiC behaves well in photothermal conversion. In other words, microPCMs have potential in solar energy utilization and thermal energy storage.