Nanofiber fluorescence coating for evaluation of complex solid-/gas-multi-phase and nano-/micro- multi-scale nanocomposite foam structure

Abstract Dual fluorescence design based on chemical coating and physical staining was successfully applied in revealing the multi-phase and multi-scale structure simultaneously in nanocomposite foams for the first time (that is nanometer-scale solid phase fillers selectively located chemical coating fluorescence, micrometer-scale solid phase cell walls selectively located physical staining fluorescence and air phase bubbles selectively located no fluorescence). The hybrid fluorescence modification method enables us to selectively locate different fluorescence dyes on nanofiber surface and in polymer matrix. Furthermore, quantitative analysis of the three-dimensional (3D) nanofiber network structure in nanocomposite foams is studied in-depth via numerical reconstruction. The evolution of 3D nanofiller network structure in multi-phase and multi-scale nanocomposite foams is demonstrated via both experimental visualization and numerical calculation. It is found that the average shortest nanofiber distance decreases with increasing cell wall thickness and with decreasing air content. Therefore, the dual fluorescence design exploring 3D functional filler network structure in complicated multi-phase and multi-scale nanocomposite foams greatly helps researchers study the structure-performance relationship of multi-functional materials with nanoscale functional fillers.