Surface Characterization Of Functionalized Polymer Nanofiber By Atomic Force Microscope(AFM)

With the development of nanotechnology, new nanomaterials have been a hot research field in materials area, including textile materials. Fibers and textiles are no longer used as they used to be. They have been used not only in clothing but also in decoration and industry, and the nanofibers with large specific surface area and high porosity have great potential applications in many industries. Various techniques have been used to functionalize polymer nanofibers in order to meet the needs of different applications.In this paper, the polyamide 6 (PA6) nanofibers was prepared by electrospinning, firstly. The results of the experiments indicated that the spinnable range of polymer solution concentration was between 8 wt. % and 18 wt. %, and the diameter of the nanofibers was about 300nm. During the experiments, 15wt. % polymer solution concentration was prepared, a high voltage of 14kV, a collecting distance of 10cm and a needle of 0.7mm diameter were applied and a common injection rate of syringe pump of 0.2ml/h was set. Meanwhile, atomic force microscopy (AFM) was used for the examination of different structures of nanofibers, including ribbon and circular structures. It was also used to measure the diameter of nanofibers and surface mechanical properties of the nanofibers.Secondly, a magnetron sputtering system was used to deposit zinc oxide (ZnO) onto the surface of the polyamide 6 nanofibers. It gave nanofibers a new characteristic of anti-ultraviolet. Then, AFM was used to observe the microstructure of the functionalized nanofibers. The growth modes of ZnO film deposited respectively on the surface of mica and polyamide 6 nanofibers were analyzed and compared. The result showed that the growth modes of ZnO film deposited on the surface of mica was stranski-krastanov mode, but the growth mode of ZnO deposited on the surface of PA6 nanofibers was volmer-weber mode, also the growth mode were similar in the small area. AFM was also employed to study the difference of surface frictional forces and adhesion between nanofibers and ZnO film deposited on the nanofiber.Finally, EDX was used to verify the existence of ZnO on the surface of the nanofibers, and ultraviolet spectrophotometer was adopted to analyze their anti-ultraviolet properties. The results of UV/VIS spectrophotometer indicated that the transmittance of nanofibers in ultraviolet (UV) would be higher than which have deposited ZnO on the surface of nanofibers, indicating the better anti-ultraviolet property of the nanofibers after sputtering.The article has examined the feasibility of the functionalization of polymer nanofibers by sputtering. Sputter coating can not only maintain the outstanding properties of polymer nanofibers, but also give them new function. Therefore, the functional nanofibers with new functions have great potential applications.