Bohra Bhashkar Singh, Pandey Neema, Tatrari Gaurav, Rana Sravendra, Sahoo Nanda Gopal
Prof. Rajendra Singh Nanoscience and Nanotechnology Centre, Department of Chemistry, Kumaun University, D.S.B. Campus, Nainital-263002, Uttarakhand, India.
University of Petroleum and Energy Studies (UPES), School of Engineering, Energy Acres, Bidholi, Dehradun-248007, Uttarakhand, India.
Soft Matter. 2022 May 25;18(20):3981-3992. doi: 10.1039/d2sm00143h.
Herein, we report a robust approach for the selective covalent functionalization of graphene oxide (GO) with 4-hydroxybenzoic acid (HBA) for developing polymeric nanocomposites based on liquid crystalline polymers (LCPs). The functionalization of GO with HBA was confirmed by Raman spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD) spectroscopy. The surface morphology of GO and functionalized GO (FGO) was studied using field emission scanning electron microscopy (FE-SEM). Furthermore, the interactions between FGO and LCPs have been investigated by FT-IR spectroscopy, whereas dispersion of GO and FGO in the LCP matrix was analyzed by FE-SEM. The better dispersion of FGO can be attributed to the hydrogen bonding and π-π stacking interactions between FGO and LCPs. Our results showed that even the addition of 5 wt% FGO in the LCP matrix significantly enhances the tensile strength and storage modulus of the pristine LCPs by 84% and 78% respectively. Compared to neat LCPs, FGO incorporated composites also demonstrate an improvement in the melting temperature () by 11 °C and glass transition temperature () by 12 °C. Furthermore, thermogravimetric analysis (TGA) was performed to evaluate the thermal stability of the composite. The 5 and 50% decomposition temperature for the LCP/FGO nanocomposites (containing 5 wt% FGO) increased by 75 °C and 107 °C respectively.
在此，我们报道了一种用于氧化石墨烯（GO）与4-羟基苯甲酸（HBA）进行选择性共价功能化的稳健方法，以开发基于液晶聚合物（LCP）的聚合物纳米复合材料。通过拉曼光谱、傅里叶变换红外（FT-IR）光谱和X射线衍射（XRD）光谱证实了GO与HBA的功能化。使用场发射扫描电子显微镜（FE-SEM）研究了GO和功能化GO（FGO）的表面形态。此外，通过FT-IR光谱研究了FGO与LCP之间的相互作用，而通过FE-SEM分析了GO和FGO在LCP基质中的分散情况。FGO更好的分散可归因于FGO与LCP之间的氢键和π-π堆积相互作用。我们的结果表明，即使在LCP基质中添加5 wt%的FGO，也能分别显著提高原始LCP的拉伸强度和储能模量84%和78%。与纯LCP相比，掺入FGO的复合材料的熔点（）提高了11°C，玻璃化转变温度（）提高了12°C。此外，进行了热重分析（TGA）以评估复合材料的热稳定性。LCP/FGO纳米复合材料（含有5 wt% FGO）的5%和50%分解温度分别提高了75°C和107°C。
