Preparation and characterization of the properties of polyethylene glycol @ Si3N4 nanowires as phase-change materials

• Si3N4 nanowires were a perfect carrier matrix to form shape-stabilized PCMs.
• The preparation time of PCMs was shortened by ultrasonic cell disruptor.
• Mechanism of preparing PCMs with Si3N4 nanowires was systematically discussed.
• Latent heat, stability, and thermal properties of PCMs were excellent.

In this study, novel polyethylene glycol @ Si3N4 nanowires as phase-change materials (PCMs) were developed by using ultrasonic cell disruptor. The results obtained herein indicate that these nanowires can be a potential carrier for preparing PCMs. The results show that PEG is composited in a fluffy nano-network structure of Si3N4 nanowires, which could not be easily leaked from this structure for the solid–liquid phase transition. X-ray diffraction and Fourier transform infrared spectroscopy were employed for investigating the structures of PCMs; the results show that a chemical reaction does not occur between PEG and Si3N4 nanowires. Differential scanning calorimetry analysis results indicated that PCMs exhibit appropriate phase-change temperature and excellent high-phase change enthalpy. From the TGA results, PCMs exhibit perfect thermal stability. The PCMs could perfectly maintain their phase transition after 100 melting–freezing cycles. The thermal conductivity of PCMs-1 was 0.362 W/(mK), which was enhanced by 88.54% in comparison with that to pure PEG. The heat storage or release rate of PCMs is significantly more rapid than that of pure PEG for practical applications.

The novel polyethylene glycol @ Si3N4 nanowires as phase-change materials (PCMs) have an optimum phase change temperature, an excellently high enthalpies of phase change, a perfect thermal stability, and the excellent heat storage/release rate.Figure optionsDownload as PowerPoint slide