Yielding Behavior in Colloidal Glasses: Comparison between "Hard Cage" and "Soft Cage"

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	Yielding Behavior in Colloidal Glasses: Comparison between "Hard Cage" and "Soft Cage"
	Zhou, Z ; Hollingsworth, JV ; Hong, S ; Cheng, H ; Han, CC
刊名	LANGMUIR
	2014
卷号	30 期号:20 页码:5739
ISSN号	0743-7463
通讯作者	Cheng, H (reprint author), Inst High Energy Phys, China Spallat Neutron Source, Dongguan 523803, Guangdong, Peoples R China.
中文摘要	Rheological measurements are utilized to examine the yielding behavior of a polystyrene (PS) core and poly(N-isopropylacrylamide) (PNIPAM) shell microgel system with varying shell/core ratio. For a shell/core ratio of 0.15 at high concentrations, the suspensions show a typical hard sphere (HS) yielding response where the loss modulus (G '') exhibits a single peak due to cage breaking. As a result of tighter cages and less cage distortion prior to yielding, the peak location of G '' decreases with volume fraction. For a shell/core ratio of 1.10, which behaves like a soft jammed glass at high concentration, the suspensions exhibit a one-step yielding behavior similar to that of HS glass. However, the location of the peak in G '' increases with volume fraction, demonstrating the important role of particle deformation in the breakage of cages. For an intermediate shell/core ratio of 0.34, the system displays a two-step yielding behavior, as observed in previous reports for attractive glasses. By increasing the volume fraction, the strain of the first peak increases while the second one decreases. In addition, as the effective volume fraction increases to 112%, the two peaks merge into one broad peak. It is demonstrated that the first peak of G '' is due to deformation of the shell, and the second peak of G '' is attributed to cage breaking as a result of the cores colliding with each other. Combining these results, a yielding state diagram from typical HS to soft jammed glass is demonstrated.
资助信息	National Basic Research Program of China (973 Program) [2012CB821500]; National Natural Scientific Foundation of China [21174152]; Capital (Beijing) Science & Technology Resources Platform [Z131110000613065]; National Science Foundation [OISE-1159189]
语种	英语
公开日期	2015-04-14
内容类型	期刊论文
源URL	[http://ir.iphy.ac.cn/handle/311004/59301]
专题	物理研究所_物理所公开发表论文_物理所公开发表论文_期刊论文
推荐引用方式 GB/T 7714	Zhou, Z,Hollingsworth, JV,Hong, S,et al. Yielding Behavior in Colloidal Glasses: Comparison between "Hard Cage" and "Soft Cage"[J]. LANGMUIR,2014,30(20):5739.
APA	Zhou, Z,Hollingsworth, JV,Hong, S,Cheng, H,&Han, CC.(2014).Yielding Behavior in Colloidal Glasses: Comparison between "Hard Cage" and "Soft Cage".LANGMUIR,30(20),5739.
MLA	Zhou, Z,et al."Yielding Behavior in Colloidal Glasses: Comparison between "Hard Cage" and "Soft Cage"".LANGMUIR 30.20(2014):5739.