Heidari Mina, Bahrami Hajir, Ranjbar-Mohammadi Marziyeh
Textile Engineering Department, Amirkabir University of Technology, Tehran, Iran.
Textile Engineering Department, Amirkabir University of Technology, Tehran, Iran.
Mater Sci Eng C Mater Biol Appl. 2017 Sep 1;78:218-229. doi: 10.1016/j.msec.2017.04.095. Epub 2017 Apr 18.
Recently graphene-based materials have been exploited widely in graphene-polymer nanocomposites and hold notable potential for various applications. In this study novel graphene-incorporated poly(caprolactone)/gelatin nanofibrous web were produced by electrospinning technique using acetic acid as a cost-effective eco-friendly solvent. Response surface methodology was used for optimizing the diameter of the electrospun nanofibrous web. To tailor electrospun nanofibers with suitable mechanical and electrical properties, the impact of affecting electrospinning parameters was studied. Our results show that, with increasing the PCL/gelatin ratio, the diameter of nanofibers increases, whereas increasing graphene concentration decreased the diameter of nanofibers up to an optimum content. With the incorporation of 1.5% graphene into PCL/gelatin matrix the tensile strength and Young modulus of nanofibrous mat considerably increased by 117 and 128% respectively. The electrical conductivity results demonstrated that nanofibrous mats own nearly 11 times higher conductivity than that of PCL/gelatin nanofibers when the graphene concentration reached the percolation threshold. Contact angle measurements confirmed that graphene-incorporated electrospun nanofibers were more hydrophilic than that of neat nanofibrous mats. Cellular toxicity results of electrospun nanofibers ascertained almost no toxicity to PC12 cells. The morphology of electrospun nanofibers was investigated by means of scanning electron microscopy (SEM). FTIR and DSC analysis revealed that there might be possible interactions between graphene and PCL/gelatin matrix. XRD analysis demonstrated that graphene-incorporated PCL/gelatin nanofibers exhibited higher crystallinity. The uniform dispersion of graphene nanosheets in nanofibrous mat was also verified through Raman spectroscopy.
近年来，基于石墨烯的材料在石墨烯-聚合物纳米复合材料中得到了广泛应用，并在各种应用中具有显著潜力。在本研究中，采用静电纺丝技术，以醋酸作为经济高效的环保型溶剂，制备了新型的石墨烯掺杂聚己内酯/明胶纳米纤维网。采用响应面法优化静电纺纳米纤维网的直径。为了制备具有合适机械和电学性能的静电纺纳米纤维，研究了影响静电纺丝参数的作用。我们的结果表明，随着聚己内酯/明胶比例的增加，纳米纤维的直径增大，而石墨烯浓度的增加会使纳米纤维直径减小，直至达到最佳含量。在聚己内酯/明胶基质中掺入1.5%的石墨烯后，纳米纤维毡的拉伸强度和杨氏模量分别显著提高了117%和128%。电导率结果表明，当石墨烯浓度达到渗流阈值时，纳米纤维毡的电导率比聚己内酯/明胶纳米纤维高近11倍。接触角测量证实，掺入石墨烯的静电纺纳米纤维比纯纳米纤维毡更具亲水性。静电纺纳米纤维的细胞毒性结果表明，其对PC12细胞几乎没有毒性。通过扫描电子显微镜（SEM）研究了静电纺纳米纤维的形态。傅里叶变换红外光谱（FTIR）和差示扫描量热法（DSC）分析表明，石墨烯与聚己内酯/明胶基质之间可能存在相互作用。X射线衍射（XRD）分析表明，掺入石墨烯的聚己内酯/明胶纳米纤维具有更高的结晶度。拉曼光谱也证实了石墨烯纳米片在纳米纤维毡中的均匀分散。
