Welding nanofiber and microsphere with carbon dioxide

Two types of micro/nano structures, microsphere and nanofibre, were prepared by electro spinning technique and spray drying technique, with the soluble fluorinated poly (ether ether ketone) (3F-PEEK) as the matrix. The micro/nano structures were exhibited in the scanning electron microscope (SEM) micrograghs, and the separated nanofibre and microsphere were observed. The sizes of micro/nano structures were measured by the statistical analysis method. We designed experiments to connect up all the micro/nano structures to form new three dimensional micro/nano structures that were observed by SEM. In the experiments, supercritical carbon dioxide (CO₂) was selected as the welding solvent. A series of nanofibers were welded to form three dimensional netlike structures, and the particles were welded to form a porous film. The welding processes were studied by varying the exposure temperature, and the welding mechanism was discussed.