Deposition of graphenic nanomaterials from elevated temperature premixed stagnation flames
Deposition of graphenic nanomaterials from elevated temperature premixed stagnation flames
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高温预混停滞火焰沉积石墨烯纳米材料
DOI：
10.1016/j.jaecs.2023.100178
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发表时间：
2023
影响因子：
--
通讯作者：
Camacho, Joaquin
中科院分区：
文献类型：
--
作者：
Dasappa, Shruthi;Camacho, Joaquin
这项工作研究了碳纳米粒子的独特纳米结构，从烟灰预混火焰与火焰温度超过2200 K。这种火焰温度状态先前已经显示出从典型的烟灰形成条件过渡到火焰形式碳采用比烟灰有序得多的纳米结构的状态。高分辨率透射电镜（HRTEM）观察到的石墨碳沉积物在这里证实了以前的拉曼光谱证据。预混拉伸稳定火焰的使用，使粒子的生产在高温制度下的流场服从低维火焰建模。虽然火焰流配置是相对简单的，三种样品制备方法被用来评估真实的碳性能，因为它们存在于火焰中的代表性。对快速插入沉积法、气溶胶稀释探针沉积法和碳颗粒薄膜沉积法制备的碳颗粒样品进行了高分辨透射电镜成像。从快速插入样品的图像显示无定形颗粒在轻度炭黑火焰和乱层颗粒在重度炭黑火焰。在快速插入的样品中有石墨烯结构的痕迹证据，但TEM网格上最引人注目的颗粒是石墨纳米晶体，可能是由一种新的人工结晶过程形成的。通过稀释气溶胶沉积和薄膜沉积随时间收集的颗粒的HRTEM图像显示出清晰的石墨烯结构。总体而言，通过HRTEM观察到的碳纳米结构是无定形、乱层和石墨烯碳晶格的混合物，这取决于火焰条件和取样方法。目前的工作突出了更高的火焰温度和更高的当量比对沉积的火焰形成的碳的潜在影响。即，在快速插入沉积样品中观察到石墨烯颗粒结构，但石墨烯部分在气溶胶稀释和碳颗粒膜沉积样品中最丰富。这可以指示石墨烯结构随时间在沉积表面上生长。
The work examines the unique nanostructure of carbon nanoparticles deposited from sooting premixed flames with flame temperatures exceeding 2200 K. This flame temperature regime has previously been shown to transition from typical soot formation conditions to a regime whereby the flame-form carbon adopts a nanostructure considerably more ordered than soot. Graphenic carbon deposits observed by High-resolution TEM (HRTEM) are reported here corroborating previous Raman spectroscopy evidence. The use of premixed stretch-stabilized flames enables particle production in the high-temperature regime under a flow field amenable to low-dimensional flame modeling. Although the flame flow configuration is relatively simple, three sample preparation methods are used to assess the representation of true carbon properties as they exist in the flame. HRTEM imaging is carried out on carbon particle samples prepared by rapid-insertion deposition, aerosol dilution probe deposition and carbon particle film deposition. Images from rapid-insertion samples show amorphous particles in the lightly sooting flame and turbostratic particles in the heavy sooting flame. There is trace evidence of graphenic structure in rapid-insertion samples but the most striking particles on the TEM grid are graphite nanocrystals presumably formed by a new artificial crystallization process. HRTEM images of particles collected over time by diluted aerosol deposition and film deposition show clear graphenic structures. Overall, the carbon nanostructure observed by HRTEM is a mixture of amorphous, turbostratic and graphenic carbon lattices depending on the flame condition and sampling method. The current work highlights potential impacts of higher flame temperatures and higher equivalence ratio on deposited flame-formed carbon. Namely, graphenic particle structure is observed in rapid-insertion deposition samples but graphene portions are most abundant in aerosol dilution and carbon particle film deposition samples. This may indicate that graphene structures grow on the deposition surface over time.
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影响因子：
5.2
作者：
Carbone, Francesco;Attoui, Michel;Gomez, Alessandro
通讯作者：
Gomez, Alessandro
影响因子：
7.4
作者：
Dasappa, Shruthi;Camacho, Joaquin
通讯作者：
Camacho, Joaquin
PAH 和芳香剂：富勒烯和烟灰的前体
DOI：
--
发表时间：
1996
期刊：
影响因子：
--
作者：
M. Bachmann;W. Wiese;K. Homann
通讯作者：
K. Homann
影响因子：
3.4
作者：
Bonpua, Jonathan;Yagues, Yuniba;Camacho, Joaquin
通讯作者：
Camacho, Joaquin