【摘要】 为提高氧化石墨烯(GO)的生物相容性从而扩展其在高性能生物材料制备中的应用,采用甲苯-2,4-二异氰酸酯作为桥联剂,制备了四臂星型聚乙二醇修饰氧化石墨烯(GO-TDI-sPEG),该产物在水中仍然可以稳定分散.采用傅里叶红外光谱(FTIR)、拉曼光谱(Raman)、X-射线衍射(XRD)、原子力显微镜(AFM)、透射电子显微镜(TEM)和热重分析(TGA)对接枝产物进行表征.产物在2861 cm-1和1093 cm-1处出现的特征红外吸收表明sPEG已接枝到GO上.产物的Raman光谱中D模与G模信号变弱,且ID/IG值变化不大,说明sPEG改性后的氧化石墨物理结构没有发生变化.XRD曲线上产物衍射峰消失,表明经聚合物修饰后氧化石墨被完全剥离.TGA数据表明原始GO在约160℃开始发生热失重,经修饰后,大约在260℃开始热失重,热稳定性增加了约100℃.由TEM图片可以观察到GO及改性石墨烯产物剥离程度较高,且片上分布有较多聚合物点.且AFM图片显示GO的平均厚度大约为0.85 nm,接上聚合物后部分厚度增加到约1.2 nm.更多还原

【Abstract】 In order to improve the biocompatibility of graphene oxide(GO) and enhance its application in preparing biomaterials,four-arm star polyethylene glycol(sPEG) was used to modify GO under the assistance of toluene-2,4-diisocyanate(TDI).Polyethylene glycol-modified graphene oxide(GO-TDI-sPEG) obtained by this facile method possesses high sPEG grafting density,which could be stably suspended in aqueous solutions.Fourier transform infrared spectroscopy(FTIR),Raman spectroscopy(Raman),X-ray diffraction(XRD),atomic force microscopy(AFM),transmission electron microscopy(TEM) and thermogravimetric analysis(TGA) were used to characterize the resultant material.The appearance of the characteristic absorptions at 2861 and 1093 cm-1 in FTIR spectrum,as well as the AFM and TEM micrographs indicated that sPEG was successfully grafted onto GO.No diffraction peak could be found in XRD figure of GO-TDI-sPEG,which indicated that the layers of GO-TDI-sPEG were fully exfoliated after modification.The TGA test results showed that the thermal stability of the modified GO had been greatly increased and the grafting degree of sPEG in GO-TDI-sPEG was about 12.1 wt%.更多还原