Improved energy harvesting and photothermal conversion of coaxial polyacrylonitrile/1-tetradecanol nanofibrous membrane enabled by sulfonated MPTMS-functionalized GO nanofiller towards thermal management

This paper reports the preparation of coaxial nanofibrous membranes, utilizing polyacrylonitrile (PAN) combined with sulfonated 3-mercaptopropyltrimethoxysilane-functionalized graphene oxide (GOS) as the sheath material, while 1-tetradecanol (C₁₄OH) serves as the core by a coaxial electrospinning technique. With a sheath/core ratio of 2:1, the PAN-x GOS/C₁₄OH nanofibrous membrane, containing varying amounts of GOS at 0.5, 1, and 2 wt%, exhibits exceptional shape stability, outstanding thermal energy storage and release capabilities, and enhanced photothermal conversion efficiency. As the concentration of GOS increased, the heating rate of the PAN-x GOS/C₁₄OH coaxial fibers rose significantly, revealing a distinct temperature buffering platform around 35 °C during thermal storage tests. Additionally, the GOS nanofiller markedly improved the photothermal conversion efficiency of the PAN-x GOS/C₁₄OH nanofibers, resulting in temperature increases of 1.5 °C, 5.1 °C, and 5.9 °C for x values of 0.5 %, 1 %, and 2 %, respectively. Furthermore, water washing and 100 thermal cycle tests demonstrated the favorable structural and thermal stability of the coaxial nanofibrous membranes. The fabric incorporating the PAN-x GOS/C₁₄OH nanofibrous membranes also displayed excellent temperature buffering properties. This study offers valuable insights into the photothermal conversion and thermal regulation capabilities of these nanofibrous membranes, informing their potential applications in thermal management materials.