| Gelatin, a kind of protein obtained from hydrolyzed and denatured animal skin, is a kind of bio-polymer with good water-solubility. Gelatin fiber mats with submicro and nanometer scale can simulate extracellular matrix structure of the human tissues and organs and can be used widely in the tissue engineering field because of its excellent bio-affinity. And electrospinning process is one of the most convenient and effective methods for preparation of ultrafine fibers.Firstly, electrospinning of gelatin/distilled water system was investigated. Ultrafine gelatin fibers were obtained when the processing conditions were optimized, such as the mass concentration of gelatin of 16%~25%, the voltage of 13~23kV, the receiving distance of 11~21cm. The range of diameter of gelatin fibers was 170 to 270nm. The results showed that increasing of the temperature of spinning environment was conducive to receive fibers with smaller average diameter. The average diameter of gelatin nanofibers increased when the mass concentration of gelatin solution increased. The diameter of gelatin nanofibers reduced within the increasing of the voltage. When the receiving distance increased, the diameter of gelatin nanofibers raised first and then decrease slightly.Secondly, the influence of salt ions on the electrospinning of gelatin solution was studied. It was found a small mount(below 0.6%wt) of NaCl made the electrospun gelatin fibers thinner. When the adding mount of NaCl was above 0.9%, the fibers'diameter became larger and the diameter distribution became wider. The smaller the diameter of ions was, the smaller the diameter of nanofibers was.Thirdly, Sodium dodecyl sulfate (SDS) and ethanol were added to improve the electrospinnability of the gelatin solution of 13% wt. The result demonstrated both SDS and ethanol made a reduction of beaded fibers in the electrospun gelatin fiber web. When the water/ethanol ratio was 95/5 and the adding mount of SDS was above 0.5%, the uniform gelatin ultrafine fibers of 110nm were obtained. And the finest average diameter of fibers electrospun from pure gelatin solution was about 176nm. |
