Preparation And Characterization Of Composite Nanofibers Based On PA6 Nanofibers

THE nanofibers appears some fantastic characteristics such as large surface area to volume ratio, superior adsorption ability, and flexibility in surface functionalities, so nanofiber membranes are widely used in biomedical, aviation industry and filtration engineering etc. But the single component of nanofibers results in dissatisfactory mechanical performance. The inorganic components in hybrid nanofibers can not work effectively enough since theses inorganic material is mostly be enveloped in polymers. But these methods which are applied to prepare composite nanofibers has disadvantages such as strict requirement for equipment and complicated operation. The absorption of nanofibers is applied to prepare composite nanofibers in this paper.The polyamide6 (PA6) molecule contains a large number of amide linkages which provides strong polarity to PA6. Due to the polarity, PA6 appears amazing adsorption ability besides its well-performed mechanical performance. In this paper, PA6 nanofiber works as basis to prepare multicomponent nanofiber membrane in order to meliorate the characteristic of the nanofiber membrane. PEO and TiO₂ sol are choosed as the organic and inorganic coating material. PA6 nanofibers can be coated with PEO and TiO₂ due to its own surface absorption in order to form the multicomponent nanofibers. The out layer provides the nanofibers special and well-performed characteristic and the PA6 core ensure the satisfying mechanical performance.Both absorbing and swelling are applied to form PA6/PEO multicomponent coaxial nanofibers. The SEM and TEM images show that the nanofiber acquires outstanding PA6/PEO core-shell structure when the PEO solution concentration reaches 2 wt% in absorbing and 30 wt% PEO in PA6/PEO composite nanofiber. According to FTIR, hydrogen bond is the only bond which is formed between PEO and PA6. DSC analysis tells that PA6 crystalline improves during preparing PA6/PEO coaxial nanofibers by absorbing and the PEO shell structure contains crystalline area, but the PA6 crystalline in PA6/PEO coaxial nanofibers prepared by absorbing dose not change and only a slight increase occurs in PEO crystalline. Meanwhile, mechanical performance of PA6/PEO coaxial nanofibers is related to the way they are prepared. No complicated coaxial electrospinning equipment is required and the process is convenient to operate.TiO₂ sol, which is prepared at different temperature, 20℃and 30℃, has different particle size. By surface absorbing, TiO₂ sol is fixed on the surface of PA6 nanofibers. Both nanofiber membranes and single nanofiber are characterized by SEM and TEM observation. These images shows that TiO₂ sol which is prepared at 20℃can provide a better coating. Besides van der Wals force, the FTIR graph indicates that another linkage between TiO₂ and PA6 is hydrogen bond. TG curves shows that the pyrolysis process of PA6/TiO₂ nanofibers is complicated. Photocatalysis test confirms that the different structure of PA6/TiO₂ nanofibers causes an effect on the photocatalysis. The TiO₂ coating also results in an increase in breakingstrength but a decrease in breaking elongation.