Sun Jianxiang, Ji Jingqi, Chen Zhigeng, Liu Shumei, Zhao Jianqing
School of Materials Science and Engineering, South China University of Technology Guangzhou 510641 P. R. China
The Key Laboratory of Polymer Processing Engineering, Ministry of Education Guangzhou 510641 P. R. China.
RSC Adv. 2019 Oct 16;9(57):33147-33154. doi: 10.1039/c9ra05992j. eCollection 2019 Oct 15.
Some commercially available graphene (CG) samples, actually graphite nanoplates, are difficult to be applied in polymers due to their large thickness, even though their fabrication is more cost-effective. In this work, a CG sample with a thickness of about 25 nm is pre-treated a facile acid soaking technique, and then the acid-treated CG is introduced into epoxy resin (EP) to improve the toughness while maintaining the high rigidity of the EP. The thickness of the acid-treated CG is dramatically decreased to about 1 nm, well-dispersing CG in the EP matrix. The tensile strength and the fracture energy of EP composite with 0.2 wt% acid-treated CG are increased to 85.2 MPa and 3.6 kJ m from 74.3 MPa and 2.3 kJ m of pure EP, respectively. In addition, the tensile-fractured surfaces of EP composites reveal that the toughening mechanism is mainly attributed to the crack deflection and crack pinning caused by the firmly-embedded CG nanosheets in the EP matrix. Besides, the glass transition temperature of EP composites is increased to 170.5 °C from 163.9 °C of pure EP. The present study provides a valuable approach for making use of the cost-effective graphite nanoplates to achieve a similar performance as graphene in EP.
一些市售的石墨烯（CG）样品，实际上是石墨纳米片，由于其厚度较大，即使其制备成本较低，也难以应用于聚合物中。在这项工作中，采用一种简便的酸浸泡技术对厚度约为25nm的CG样品进行预处理，然后将酸处理后的CG引入环氧树脂（EP）中，以提高其韧性，同时保持EP的高刚性。酸处理后的CG厚度显著降低至约1nm，使其在EP基体中良好分散。含有0.2wt%酸处理CG的EP复合材料的拉伸强度和断裂能分别从纯EP的74.3MPa和2.3kJ/m²提高到85.2MPa和3.6kJ/m²。此外，EP复合材料的拉伸断裂表面表明，增韧机制主要归因于EP基体中牢固嵌入的CG纳米片引起的裂纹偏转和裂纹钉扎。此外，EP复合材料的玻璃化转变温度从纯EP的163.9℃提高到170.5℃。本研究为利用成本效益高的石墨纳米片在EP中实现与石墨烯相似的性能提供了一种有价值的方法。
