Abstract：
The synthesis of graphene via traditional methods has several drawbacks, such as the release of poisonous gases, Most of these techniques are time-consuming and tedious, besides the absence of control over the structural composition of graphene during synthesis. In this study, a facile approach for the synthesis of graphene densely doped with nitrogen (N-dopped graphene (NG)) from novel precursor chitosan throughout the direct solvothermal treatment of chitosan under mild circumstances at 250 °C and 270 °C. Cetyltrimethylammonium bromide (CTAB) and ammonia are utilized as structural directing agents. FTIR, XRD, CHNS/O elemental analysis, XPS, and Raman spectroscopy are utilized to elucidate the chemical composition and purity of N-dopped graphene. The surface morphology of NG is studied by using SEM, HR-TEM, and selected area electron diffraction (SAED). The results approved that, the one-pot, single-step approach is a simple and cost-effective technique for producing a high throughput of NG, of charming microstructure features, including good graphitization, low oxidation state, good exfoliation level, and very extended lateral dimension sheets. Profound visions on the growing mechanism have been proposed. The incorporation effect of NG to cement mortar is also studied. Two percentages of NG 0.05 wt% and, 0.10 wt% from the total cement mass were utilized. A microstructural investigation of incorporated NG on cement mortar is studied by conducting AFM, and SEM. Furthermore, workability and mechanical characterizations including, compressive strength, and flexural strength are investigated. Also, the dynamic mechanical parameters including storage modulus and loss factor are studied. It is noticed that the workability decreased from 14.8 % to 7.8 % with the addition of 0.05 wt% and 0.1 wt% NG respectively. However, the maximum increments of the compressive strength were 35 % for the mortar containing 0.1 wt% NG and flexural strength increased three times than the unmodified one. Also, the cement mortar containing 0.1 wt% NG has a storage modulus of 12 MPa compared to unmodified 1 MPa and has the lowest loss factor (damping coefficient). These results verified that incorporating NG nanosheets in cement has a positive effect on reinforcing cement mortar.
摘要：
通过传统方法合成石墨烯具有几个缺点,例如释放有毒气体，这些技术大多耗时且乏味，除了在合成过程中不控制石墨烯的结构组成。在这项研究中,在250°C和270°C的温和环境下，通过壳聚糖的直接溶剂热处理，从新型前体壳聚糖合成氮掺杂的石墨烯（N-掺杂石墨烯（NG））的简便方法。十六烷基三甲基溴化铵(CTAB)和氨被用作结构导向剂。FTIR,XRD,CHNS/O元素分析,XPS,和拉曼光谱用于阐明N-掺杂石墨烯的化学组成和纯度。利用SEM对NG的表面形貌进行了研究,HR-TEM,和选定区域电子衍射(SAED)。结果证明，一罐,单步法是一种简单且经济有效的技术，用于生产高产量的NG，迷人的微观结构特征，包括良好的石墨化，低氧化态，良好的去角质水平，和非常延伸的横向尺寸表。已经提出了关于增长机制的深刻愿景。还研究了NG在水泥砂浆中的掺入效果。两个百分比的NG0.05wt%和，使用总水泥质量的0.10重量%。通过进行AFM研究了水泥砂浆上掺入NG的微观结构研究，和SEM。此外，可加工性和机械特性，包括，抗压强度,和抗弯强度进行了研究。此外，研究了储能模量和损耗因子等动态力学参数。注意到,随着分别添加0.05重量%和0.1重量%的NG,可加工性从14.8%降低至7.8%。然而,对于含有0.1wt％NG的砂浆，抗压强度的最大增量为35％，弯曲强度比未改性的砂浆增加了三倍。此外，与未改性的IMPa相比,含有0.1重量%NG的水泥砂浆具有12MPa的储能模量,并且具有最低的损耗因子(阻尼系数)。这些结果验证了在水泥中掺入NG纳米片对增强水泥砂浆具有积极作用。
