Smart thermal phase change materials with switchable morphology

Smart phase change materials (PCMs) have been carefully engineered using cutting-edge manufacturing techniques to meet specific application requirements. A multifunctional phase change composite has been developed by combining polyethylene glycol (PEG2000) binary eutectic, sodium stearate (NaR) micro−/nano-medium, and iron powder as raw materials. The binary eutectic PCM provides the composite with plasticity at room temperature. The addition of an appropriate amount of sodium stearate enhances the dispersibility of high-density iron powder (7.86 g cm −3 ) within the PCM, without altering the intrinsic morphology of the binary eutectic (1.27 g cm −3 ) before or after melting. As a result, the functional composite exhibits several attractive properties, including morphology switchability under external forces, temperature, and magnetic fields, asymmetric transmission of electrical signals in temperature gradients, efficient photo-thermal conversion, and excellent thermal storage performance. This self-prepared functional composite holds great potential for applications in drug delivery, morphology control in confined spaces, temperature management in building materials and electronic components, as well as electrical signal transmission across varying temperatures.