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首页> 外文期刊>Synthetic Metals >Nanospace due to the presence of boron and nitrogen in carbon films prepared from polyimide
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Nanospace due to the presence of boron and nitrogen in carbon films prepared from polyimide

机译：由聚酰亚胺制备的碳膜中存在硼和氮，从而形成纳米空间

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Kapton-type polyimide films with and without boron incorporated (symbols PI-SB and PI) were carbonized and graphitized up to 2600 deg C with the aim of creating nanospaces into carbon by doping boron and/or nitrogen and characterizing them. Carbonization of PI and commercially available polymer films containing nitrogen revealed that nitrogen atoms, which are the substitute for carbon atoms in the hexagonal structure, remained at 1200 deg C, independent of the structure of polymers. The dissolved nitrogen in PI disappeared above 2400 deg C. The nitrogen atoms trap most of the extra electrons introduced by themselves and do not cause much imbalance of net charge around them. The nitrogen atom, however, slightly displaces (ca. 0.02 nm) from the plane and breaks planar structure due to C-N bond nature. These two factors create electronically and geometrically unique nanospaces in carbon hexagonal structure. On carbonizing PI-SB, B-N bonds started to form in the films around 800 deg C, and these bonds were broken above 1200 deg C and boron atoms started to substitute carbon atoms in the turbostratic structure. The B-N bonds disappeared above 2200 deg C but the dissolved boron did not even at 2600 deg C. The dissolved boron atoms and B-N bonds create imbalance of net charge around them, leading to the increment of hole concentration. They do not break planar structure of carbon hexagonal layer but are presumed to create edges or boundaries of crystals, leading to the increment of structural defects. Accordingly, nanospaces created by boron are different from those by nitrogen.
机译：将掺有和不掺入硼的Kapton型聚酰亚胺薄膜（符号PI-SB和PI）碳化并石墨化至2600摄氏度，目的是通过掺杂硼和/或氮并对其进行表征来在碳中形成纳米空间。 PI和含有氮的可商购获得的聚合物薄膜的碳化表明，六边形结构中碳原子的替代物氮原子保持在1200℃，而与聚合物的结构无关。 PI中溶解的氮在2400摄氏度以上消失了。氮原子捕获了它们自己引入的大多数多余电子，并且不会在它们周围引起太多净电荷失衡。但是，由于C-N键的性质，氮原子会稍微偏离平面（约0.02 nm）并破坏平面结构。这两个因素在碳六边形结构中创建了电子和几何上独特的纳米空间。在碳化PI-SB时，在800摄氏度左右的薄膜中开始形成B-N键，这些键在1200摄氏度以上断裂，并且硼原子开始取代涡轮层结构中的碳原子。 B-N键在2200摄氏度以上消失，但溶解的硼甚至在2600摄氏度时都没有。溶解的硼原子和B-N键在其周围产生净电荷不平衡，从而导致空穴浓度增加。它们不会破坏碳六边形层的平面结构，但被认为会产生晶体的边缘或边界，从而导致结构缺陷的增加。因此，由硼产生的纳米空间不同于由氮产生的纳米空间。

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