Improved quantification of curvature in high-resolution transmission electron microscopy lattice fringe micrographs of soots
Improved quantification of curvature in high-resolution transmission electron microscopy lattice fringe micrographs of soots
复制标题
改进了高分辨率透射电子显微镜烟灰晶格条纹显微照片中曲率的量化
DOI：
10.1016/j.carbon.2017.02.059
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发表时间：
2017-06-01
期刊：
影响因子：
10.9
通讯作者：
Mathews, Jonathan P.
中科院分区：
文献类型：
--
作者：
Wang, Chang'an;Huddle, Thomas;Mathews, Jonathan P.
煤烟影响气候变化和人类健康。它的结构受燃料和燃烧条件的影响。高分辨率透射电子显微镜晶格条纹的图像分析表明曲率是常见的，并影响反应性。在这里，改进的曲率量化确定的分布段频率，段长度，段之间的角度，拐点的频率，相对拐点的位置，和总的角度变化为每个条纹的三个烟灰和炭黑。在28-49%的条纹中存在曲率。低曲率（< 30度）占最大部分（61-76%）。最常见的屈曲角度为10-20度。几何优化（从头算）原子模型含有位于中心的五边形环或石掷威尔士缺陷的角度变化19-77度，这取决于视角和分子。大多数弯曲条纹（71-78%）有一个奇异的拐点。条纹主要在6-15.0埃长度范围内，4-100度累积角。迂曲度数据表明，该常用参数在评价波动曲率方面存在局限性。将这些数据与结构缺陷联系起来将增强将反应性与结构联系起来，捕获和改进原子表示中的结构特征。然而，小于45度的节段角度的变化不太可能与中心放置的孤立五边形环相关。(C)2017爱思唯尔有限公司版权所有
Soot affects climate change and human health. Its structure is influenced by fuel and combustion conditions. Image analysis of high-resolution transmission electron microscopy lattice fringes indicates curvature is common and impacts reactivity. Here an improved curvature quantification determined the distributions of segment frequency, segment lengths, angles between segments, frequency of inflection points, relative inflection point locations, and overall angle changes for each fringe for three soots and a carbon black. Curvature was present in 28-49% of the fringes. Low curvature (< 30 degrees) account for the largest portion (61-76%). The most common inflection angles were 10-20 degrees. Geometry optimized (ab initio) atomistic models containing centrally located pentagon rings or Stone-Thrower-Wales defects had angle changes 19-77 degrees depending on viewing angle and molecule. The majority of curved fringes (71-78%) had a singular inflection point. Fringes were primarily within the range 6-15.0 angstrom length 4-100 degrees cumulative angle. Tortuosity data demonstrated this commonly used parameter was limited for the evaluation of undulating curvature. Linking these data to structural defects will enhance linking reactivity to structure, capturing and improving structural features in atomistic representations. Changes in segment angles < 45 degrees however are not likely to be associated with centrally placed isolated pentagon rings. (C) 2017 Elsevier Ltd. All rights reserved.