Nanoburl Graphites
Nanoburl Graphites
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DOI：
10.1002/adma.202007513
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发表时间：
2021-03
影响因子：
29.4
通讯作者：
Kunpeng Lin;Hailiang Fang;A. Gao;Hui Yu;Lianjun Wang;Qian Yu;L. Gu;Qinghua Zhang;Jianlin Li;Wan Jiang
中科院分区：
文献类型：
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作者：
Kunpeng Lin;Hailiang Fang;A. Gao;Hui Yu;Lianjun Wang;Qian Yu;L. Gu;Qinghua Zhang;Jianlin Li;Wan Jiang
石墨应用的一个关键挑战是低强度，这源于石墨（0002）面的容易解理。受树干中观察到的节强化机制的启发，将转化为石墨洋葱的纳米金刚石颗粒用作嵌入石墨（0002）晶格平面中的“纳米壁”，以消除通过放电等离子体烧结由石墨粉末制备的块状石墨的石墨（0002）平面解理。通过在石墨洋葱和薄片之间的界面处的sp3杂化在碳原子之间建立共价键，这触发电子重新分布以在内部形成正/负电荷域。因此，通过杂化产生了成对的伪肖特基结，这进一步增强了石墨洋葱和薄片之间的结合。通过这些结合机制，并且通过与纳米金刚石到石墨洋葱的变化相关的体积膨胀填充石墨粉末之间的空隙，石墨粉末的松散压实在1700 °C下变得固结。所提出的纳米球机制显示了其潜力，并赋予纳米球石墨的强度是由石墨粉末制备的常规石墨的五倍。纳米球强化的概念在其他层状材料的微结构设计和性能增强中可能是重要的。
A critical challenge for the application of graphite is low strength, which originates from the easy cleavage of graphite (0002) planes. Inspired by the burl strengthening mechanism observed in tree trunks, nanodiamond particles converted into graphite onions are used as “nanoburls” embedded in graphite (0002) lattice planes to eliminate the graphite (0002) plane cleavage of bulk graphites prepared by spark plasma sintering from graphite powders. Covalent bonds are built between carbon atoms by sp3 hybridization at the interface between the graphite onions and flakes, which triggers an electron redistribution to form positive/negative charge domains within. Thus, pairs of pseudo‐Schottky junctions are created by the hybridization, which further enhances the bonding between the graphite onions and flakes. With these bonding mechanisms, and with voids between the graphite powders filled in by the volume expansion associated with the change of nanodiamonds to the graphite onions, the loose compaction of graphite powder becomes consolidated at 1700 °C. The proposed nanoburl mechanism shows its potential and bestows the nanoburl graphites with strength five times that of conventional graphites prepared from graphite powders. The concept of nanoburl strengthening can be important in the microstructural design and property enhancement of other layered materials.