论文标题
对纳米多孔石墨烯膜稳定性的热力学洞察力
Thermomechanical Insight into the Stability of Nanoporous Graphene Membranes
论文作者
论文摘要
多孔石墨烯（PG）是一种石墨烯衍生物，该衍生物是纳米方面架构的赋予。该材料具有特定的结构，该结构具有高孔体积的互连网络，可产生具有较大表面积的膜。实验表明，PG结合了显着的特性，例如高机械强度和良好的热稳定性。在这项工作中，我们进行了完全原子的反应性（RAEXFF）分子动力学模拟，以对2D多孔N-苯甲酸-CMP（CMP和N分别提及PI偶联的微型孔的Polymers and poremeter the Porefortion the Membranement）进行全面研究。为了进行比较，结果也与具有相似维度的石墨烯片的结果形成鲜明对比。我们采用了三个不同的纳米孔直径：小（3.45 A），中（8.07 A）和大（11.93 A）。结果表明，PG的热稳定最高为4660K，比石墨烯熔点（5643K）小约1000k。在PG加热期间，线性原子链形成结合碳和氢原子。通过在两个平面方向上施加单轴负荷的温度，裂缝菌株的范围在15％-34％之间。断裂应变与纳米多孔大小成比例地增加。值得注意的是，PG完全断裂的临界拉伸强度与温度无关。相反，它仅取决于纳米孔直径。在临界应变阈值之后，所有PG膜突然从弹性到完全断裂的态度。
Porous graphene (PG) is a graphene derivative endowed of nanoporous architectures. This material possesses a particular structure with interconnected networks of high pore volume, producing membranes with a large surface area. Experiments revealed that PG combines remarkable properties such as high mechanical strength and good thermal stability. In this work, we have carried out fully-atomistic reactive (ReaxFF) molecular dynamics simulations to perform a comprehensive study on the elastic properties, fracture mechanism, and thermal stability of 2D porous n-Benzo-CMPs (CMP and n refer, respectively, to pi-conjugated microporous polymers and the pore diameter) membranes with distinct nanoporous architectures. For comparison purposes, the results were also contrasted with the ones for graphene sheets of similar dimensions. We adopted three different nanoporous diameters: small (3.45 A), medium (8.07 A), and large (11.93 A). Results showed that PG is thermally stable up to 4660K, about 1000K smaller than the graphene melting point (5643K). During the PG heating, linear atomic chains are formed combining carbon and hydrogen atoms. The fracture strains range between 15%-34% by applying a uniaxial loading in both plane directions for temperatures up to 1200K. The fracture strain increases proportionally with the nanoporous size. Remarkably, the critical tensile strength for the PG complete fracture is temperature independent. Instead, it depends only on the nanoporous diameter. All the PG membranes go abruptly from elastic to completely fractured regimes after a critical strain threshold.
