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

doi:10.1039/d3nr04067d

CORC > 力学研究所 > 中国科学院力学研究所 > 流固耦合系统力学重点实验室(2012-)

	Atomistic mechanisms underlying plastic flow at ultralow yield stress in ductile carbon aerogels
	Conter, Giorgio 5; Xiao, Kailu 4; Wu, Xianqian 3; Goddard III, William A.2; Fortunelli, Alessandro 1,2
刊名	NANOSCALE
	2023-11-28
页码	8
ISSN号	2040-3364
DOI	10.1039/d3nr04067d
通讯作者	Goddard III, William A.() ; Fortunelli, Alessandro(alessandro.fortunelli@cnr.it)
英文摘要	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.
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
WOS关键词	REACTIVE FORCE-FIELD ; REAXFF
WOS研究方向	Chemistry ; Science & Technology - Other Topics ; Materials Science ; Physics
语种	英语
WOS记录号	WOS:001112658200001
资助机构	Division of Chemical, Bioengineering, Environmental, and Transport Systems ; Italian Cineca Supercomputing Center ; COST Action ; COST (European Cooperation in Science and Technology) ; NSF
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/93560]
专题	力学研究所_流固耦合系统力学重点实验室(2012-)
通讯作者	Goddard III, William A.; Fortunelli, Alessandro
作者单位	1.CNR, ThC2 Lab, CNR ICCOM, Area Ric, Via G Moruzzi 1, I-56124 Pisa, Italy 2.CALTECH, Mat & Proc Simulat Ctr MSC, Pasadena, CA 91125 USA 3.Chinese Acad Sci, Inst Mech, Beijing 100190, Peoples R China 4.Texas A&M Univ, Dept Mat Sci & Engn, College Stn, TX 77840 USA 5.Scuola Normale Super Pisa, Piazza Cavalieri 7, I-56125 Pisa, Italy
推荐引用方式 GB/T 7714	Conter, Giorgio,Xiao, Kailu,Wu, Xianqian,et al. Atomistic mechanisms underlying plastic flow at ultralow yield stress in ductile carbon aerogels[J]. NANOSCALE,2023:8.
APA	Conter, Giorgio,Xiao, Kailu,Wu, Xianqian,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.