Atomistic mechanisms underlying plastic flow at ultralow yield stress in ductile carbon aerogels

doi:10.1039/d3nr04067d

IMECH-IR > 流固耦合系统力学重点实验室

	Atomistic mechanisms underlying plastic flow at ultralow yield stress in ductile carbon aerogels
	Conter, Giorgio; Xiao KL(肖凯璐); Wu XQ(吴先前); Goddard III, William A.; Fortunelli, Alessandro
通讯作者	Goddard III, William A.() ; Fortunelli, Alessandro(alessandro.fortunelli@cnr.it)
发表期刊	NANOSCALE
	2023-11-28
页码	8
ISSN	2040-3364
摘要	We investigated carbon aerogel samples with super low densities of 0.013 g cm-3 (graphite is 2.5) and conducted compression experiments showing a very low yield stress of 5-8 kPa. To understand the atomistic mechanisms operating in these super low density aerogels, we present a computational study of the mechanical response of very low-density amorphous carbonaceous materials. We start from our previously derived atomistic models (based on the DynReaxMas method) with a density of 0.16 g cm-3 representing the core regions of carbon aerogels. We considered three different phases exhibiting either a fiber-like clump morphology interconnected with string-like units or a more reticulated framework. We subjected these phases to compression and shear deformations and analyzed the resulting plastic response via an inherent-structure protocol. Strikingly, we find that these materials possess shear plastic relaxation modes with extremely low values of yield stress, negligible with respect to the finite values predicted outside this "zero-stress" region. This is followed by a succession of two additional regimes with increasing yield stress values. Our analysis of the atomistic relaxation mechanisms finds that these modes have a collective and cooperative character, taking the form of nanoscopic shear bands within the clumps. These findings rationalize our experimental observations of very low-stress plastic deformation modes in carbon aerogels, providing the first steps for developing a predictive multi-scale modeling of the mechanical properties of aerogel materials. The phenomenon of plastic flow at ultra-low yield stress in super-low density ductile carbon aerogels from experimental measurements to its theoretical understanding via atomistic structures and deformation mechanisms.
DOI	10.1039/d3nr04067d
收录类别	SCI ; EI
语种	英语
WOS记录号	WOS:001112658200001
关键词[WOS]	REACTIVE FORCE-FIELD ; REAXFF
WOS研究方向	Chemistry ; Science & Technology - Other Topics ; Materials Science ; Physics
WOS类目	Chemistry, Multidisciplinary ; Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Physics, Applied
资助项目	Division of Chemical, Bioengineering, Environmental, and Transport Systems ; Italian Cineca Supercomputing Center[CA21101] ; COST Action ; COST (European Cooperation in Science and Technology)[CBET-1805022] ; COST (European Cooperation in Science and Technology)[CBET-2005250] ; COST (European Cooperation in Science and Technology)[CBET-2311117] ; NSF
项目资助者	Division of Chemical, Bioengineering, Environmental, and Transport Systems ; Italian Cineca Supercomputing Center ; COST Action ; COST (European Cooperation in Science and Technology) ; NSF
论文分区	二类/Q1
力学所作者排名	3
RpAuthor	Goddard III, William A. ; Fortunelli, Alessandro
引用统计
文献类型	期刊论文
条目标识符	http://dspace.imech.ac.cn/handle/311007/93561
专题	流固耦合系统力学重点实验室
推荐引用方式 GB/T 7714	Conter, Giorgio,Xiao KL,Wu XQ,et al. Atomistic mechanisms underlying plastic flow at ultralow yield stress in ductile carbon aerogels[J]. NANOSCALE,2023:8.
APA	Conter, Giorgio,肖凯璐,吴先前,Goddard III, William A.,&Fortunelli, Alessandro.(2023).Atomistic mechanisms underlying plastic flow at ultralow yield stress in ductile carbon aerogels.NANOSCALE,8.
MLA	Conter, Giorgio,et al."Atomistic mechanisms underlying plastic flow at ultralow yield stress in ductile carbon aerogels".NANOSCALE (2023):8.

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