Peering into the structural evolution of glass-like carbons derived from phenolic resin by combining small-angle neutron scattering with an advanced evaluation method for wide-angle X-ray scattering
Peering into the structural evolution of glass-like carbons derived from phenolic resin by combining small-angle neutron scattering with an advanced evaluation method for wide-angle X-ray scattering
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DOI：
10.1016/j.carbon.2018.09.025
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发表时间：
2019-01-01
期刊：
影响因子：
10.9
通讯作者：
Smarsly, B. M.
中科院分区：
文献类型：
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作者：
Badaczewski, F.;Loeh, M. O.;Smarsly, B. M.
采用小角中子散射（SANS）和广角x射线散射（WAXS）数据的高级评价相结合的方法，定量表征了两种非石墨化玻璃样碳的结构演变。利用这两种方法可以研究埃级（石墨烯堆栈，WAXS）和不可接近微孔（SANS）的微观结构。应用WAXS分析为聚芳sp(2)微观结构的大小和无序度提供了定量的结构参数。因此，结合SANS-WAXS分析可以全面了解石墨烯微观结构与玻璃状碳（即非石墨化碳类）热处理后无法进入的孔隙率之间的关系。特别是，石墨化中间相沥青的模拟研究表明了所利用的碳前驱体的化学成分的主要影响。对于类玻璃碳，结果显示基本结构单元（L-a）的横向生长速率取决于温度范围，最终达到12 nm，而堆叠高度（L-c）为2.2 nm，几乎不受3000℃以下热处理的影响。因此，我们的研究将微观结构和孔隙度的演变与化学成分的变化联系起来。(C) 2018 Elsevier Ltd.版权所有。
The structural evolution of two non-graphitizing glass-like carbons derived from a liquid resole and a solid novolac-type phenolic resin was quantitatively characterized by combining small-angle neutron scattering (SANS) with an advanced evaluation for wide-angle X-ray scattering (WAXS) data. Utilizing these two methods allowed for studying the microstructure on the Angstrom level (graphene stacks, WAXS) and the inaccessible microporosity (SANS). The applied WAXS analysis provided quantitative structural parameters for both, size and disorder in the polyaromatic sp(2) microstructure. Hence, the combined SANS-WAXS analysis yielded comprehensive insights into the relation between the graphene microstructure and the inaccessible porosity upon heat treatment for glass-like carbons, i.e. a nongraphitizing class of carbon. In particular, the analogue investigation of a graphitizing mesophase pitch demonstrates the major impact of the chemical composition of the utilized carbon precursor. For the glass-like carbons the results revealed different growth rates for the lateral extent of the basic structural units (L-a) depending on the temperature range, finally reaching 12 nm, whereas the stack height (L-c) exhibiting 2.2 nm is hardly affected by the thermal processing up to 3000 degrees C. As a major finding our study thus relates the evolution of microstructure and porosity to changes in chemical composition. (C) 2018 Elsevier Ltd. All rights reserved.