Thermal conductivity of polyacrylonitrile nanofibre web in various nanofibre diameters and surface densities

The effects of variation in average nanofibre diameter and nanofibre web surface density on thermal conductivity of polyacrylonitrile nanofibre web was investigated in this study. The results demonstrate using thinner nanofibres results in a lower limit of thermal conductivity, better thermal insulation performance and a higher amount of Rosseland mean extinction coefficient that means lower radiative conductivity. It can be related to higher specific surface of thinner nanofibres that means more surface area for radiative scatter and absorption leading to lower conductivity. With the increase in the surface density of nanofibre web, thermal conductivity reduced and water vapour transmission rate and thermal insulation ability improved. Higher porosity percentage and smaller pore size in the web with higher surface density could result in lower thermal conductivity.