| It is well-known that silica is abundence in the world, as well as its good biocompatibility, and thoes with porous and hollow structure ones has attracted special attention for their unique performance in optical, electrical and hydrophilic, not to mention their characteristic inside/outside surface which would be used in further modification and drug-loading.Otherwise, electrospinning is convenience method that manages in producing one-dementional nanofiber during a short time, and shows great prospect in industrialization.Recently, people succeeded in preparing SiO2hollow nanofiber succinctly via Phase Seperation in Electrospinning. However, they did not deeply research the structural transformation caused by Phase-Seperation Mechanism during electrospinning, for which we tried to make some improvements in this system. During the experiment, we achieved electrospun silica nanofibers with porous and/or hollow inner structure. The nanofibers we got have uniform morphology, particllarly, and the BET suface of the porous silica nanofiber could reach as high as718.11m2/g, the pores are hierarchily distributed in micro, meso and macro scale. Then we changed the parameters to analysis the procedure and we noticed that, during the whole prosess, it is the major influencing factor that the mount of Polyvinyl pyrrolidone (PVP), as well as H2O, needle shape and collect distance, however, neither the voltage during electrospining nor the time of the sol-gel reaction have strong impact to the morphology of our silica nanofibers.On the other hand, the traditional used template method has clear path, and the technology is relatively mature.And it has newly developed a process of preparing porous hollow silica nanomaterials by using electrospun nanofiber as template (namely FUFT method); The existing poly (vinyl alcohol)(PVA) nanofibers, with uniform diameter distribution and certain resistance to water after physical/chemical modification, can be further utilized as the template. Therefore, this paper also used the PVA nanofibers electrospun nanofibers as template, tetraethyl ortho silicate (TEOS) as Silica source for sol-gel reaction to consructing Silica/PVA shell-core nanofibers.Finally, we got hollow silicon oxide nanometer fiber after removing PVA by calcination. The final composite nanofiber was covered by SiO2nanosphere, which got a diameter range of80-100nm. Through groping for the experimental conditions, this paper found the optimum reaction conditions:1cm2electrospun PVA nanofiber membrane,1.5ml TEOS,0.8ml ammonia,18ml ethanol.At the same time, Ag nanoparticles, known as its distinctive property in photology and electricity, always need supporter to be easily used or built up some composite material with some kind of special function, and our group had managed in loading Ag nanoparticles on the outside surface of silica microsphere, based on that, we functionazied our porous silica nonafibers with Ag nanoparticle to enlarge the application scope of the porous/hollow fiber we got by Phase Seperation in Electrospinning in this study. Resultly, the Ag nanoparticles distributed uniformly on the outside surface of the porous silica nonafibers, as well as inside pores, with the diameter of agnps ranged in10to50nm, which had proved with certain bactericidal performance by sterilization experiment.However, as prepared Ag@Silica nanofiber is quite brittle, so we tried to functionalize the flexible Silica/PVA core-shell nanofiber with agnps, and finally improved the toughness of the antibacterial composite nanofiber, which would have good performance in sterilize or woud-dressing materials. |
PDF Full Text Request