Lego-Microfluidics Generated Magnetically Responsive Bifunctional Microcapsules with Encapsulated Phase Change Material
Sumit Parvate, Seyedarash Moshtaghibana, Madhav Solanke, Nibina Nizar, Nico Leister, Philipp R. Schochat, K. Morrison, Sujay Chattopadhyay, Goran T. Vladisavljević
Abstract
High Resolution Image Download MS PowerPoint Slide We report an innovative Lego-microfluidic technology for room temperature synthesis of highly monodispersed bifunctional microcapsules enclosing phase change material (PCM), exhibiting magnetic and thermal energy storage properties. Iron(II, III) oxide (Fe 3 O 4 ) nanoparticle-embedded microcapsules encapsulating hexadecane (HD) are synthesized without external heating or cooling in just ∼80 s. The process involves forming oil-in-oil-in-water (O/O/W) double emulsion droplets with Norland Optical Adhesive (NOA) photopolymeric shell and consolidating them through on-the-fly shell polymerization using thiol–ene “click” chemistry. PCM content and magnetic properties were accurately manipulated by adjusting inner phase (PCM) flow rate and mass fraction of Fe 3 O 4 nanoparticles in the middle (polymer) phase. Microcapsules with a shell thickness of 17.1 μm achieved a maximum PCM content of 63.3%. Thermogravimetric analysis (TGA) revealed significantly enhanced thermal stability of Fe 3 O 4 nanoparticle-embedded microcapsules compared to pure PCM. Vibrating sample magnetometry (VSM) verified an increase in saturation magnetization and residual magnetization of microcapsules, having higher Fe 3 O 4 nanoparticle content. Notably, the sample containing 1% Fe 3 O 4 nanoparticles exhibited excellent magnetic properties, showcasing a saturation magnetization of 0.194 emu/g. Concurrently, the PCM microcapsules demonstrated high magnetic responsiveness and maneuverability.