Cellulose nanocrystals-composited poly (methyl methacrylate) encapsulated n-eicosane via a Pickering emulsion-templating approach for energy storage.

Microencapsulated phase change composite materials (MPCMs) with cellulose nanocrystals-composited poly (methyl methacrylate) (PMMA) as shell and n-eicosane as core was facially prepared via Pickering emulsion assisted solvent evaporation approach. PMMA and n-eicosane were dissolved in chloroform as the oil phase. Cellulose nanocrystals (CNC) can efficiently stabilize oil - in - water (O / W) emulsion, and the core-shell ratio will affect the thermal properties of MPCMs, study found that the optimal core-shell ratio was 1:2 and encapsulation ratio reached 58.2 %. The PMMA encapsulated MPCMs displayed a regular spherical shape sized in the range of 5-10 micrometers. They had favorable thermal stability and melting enthalpy of up to 150.8 J/g. Results of the thermal cycling tests showed melting enthalpy of MPCMs were maintained by over 99 % after 100 heating-cooling cycles. The proposed Pickering emulsion assisted solvent evaporation approach provides a potential way for industrial production of microencapsulated phase change materials.