A comprehensive study on optimizing and thermoregulating properties of core–shell fibrous structures through coaxial electrospinning

This study aimed to investigate the fabrication facility of thermoregulating core–shell fibers from various polymer solutions as the shell part which surrounded a phase change material (PCM) representing the core part. Fabrication process was drawn through coaxial electrospinning. Polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF) and polyacrylonitrile (PAN) were selected as the promising candidates for shell materials. n-Octadecane was loaded as the low-temperature PCM in the whole core part. The results showed that PVP had a better ability to form the core–shell structure than the other two polymers. The effect of PVP concentration solution, voltage and the flow rates of the core and shell fluid on the morphology of n-octadecane/polyvinylpyrrolidone (PCM–PVP) fibers was investigated. It was shown that there were the optimum concentration, voltage and feed rate, such that the core–shell structure could be formed without any obstacle. In addition, thermoregulation properties of the fabricated layer were examined with DSC analysis and the simulated body condition setup. DSC results illustrated the phase change enthalpy of about 80 J g−1, which was related to the PCM–PVP with the PVP concentration of 14% and the shell/core flow rate of 2.0/0.25 ml h−1. There was an encapsulation ratio of about 36%. Simulated body condition also showed the temperature difference of 10 °C between the PVP and the PCM–PVP layer at the phase change temperature, which provided valuable results for considering this layer for intelligent textiles.