Interfacial properties and phase transitions in ternary symmetric homopolymer-copolymer blends: A dissipative particle dynamics study

doi:10.1016/j.polymer.2013.02.011

CORC > 化学研究所 > 中国科学院化学研究所

	Interfacial properties and phase transitions in ternary symmetric homopolymer-copolymer blends: A dissipative particle dynamics study
	Bai, Zhiqiang 1,2,3; Guo, Hongxia 1,2,3
刊名	POLYMER
	2013-04-03
卷号	54 期号:8 页码:2146-2157
关键词	Symmetric Ternary Blend Interfacial Property Phase Transition
ISSN号	0032-3861
DOI	10.1016/j.polymer.2013.02.011
英文摘要	We use dissipative particle dynamics simulations to study the interfacial properties and their relevance to the phase transitions in ternary symmetric blends. For the blend in the lamellar (LAM) state, by analyzing the distribution of inter-bilayer distances as well as the position fluctuations and correlations of bilayers, we found that the "Discrete Harmonic" theory can describe the fluctuations of the LAM phase in ternary blends in a satisfactory way when the LAM phase is not too close to the phase transition to the bicontinuous microemulsion (B mu E). In particular, as the LAM stack is swollen increasingly with the addition of homopolymers, the bilayers in the LAM phase experience a crossover from the single coherent fluctuation mode to the coexisting of coherent and incoherent fluctuation modes wherein the incoherent free membrane regime starts at larger length scales and becomes more pronounced. Meanwhile, the in-plane correlation length increases, the bending modulus and compressibility modulus decrease, indicating that as the more homopolymers are added, fluctuations between adjacent bilayers become less coherent, bilayers become more flexible, and the highly swollen LAM system becomes more susceptible to thermal fluctuations. Therefore, the phase transition from LAM to B mu E is expected to occur when the bending modulus turns out to be within KBT or when the persistent length is no larger than the lamellar spacing. Also the two criteria yield the same predictions for the transition point. While for the macrophase-separated (2P) phase, we found that Helfrich model gives a good description of the fluctuation spectrum of the copolymer monolayer at long wavelengths if the 2P systems are not too close to the phase transition to B mu E. With the addition of copolymers the interfacial tension reduces but the bending modulus increases. Moreover, the phase transition of 2P to B mu E coincides with the saturation of the interface between homopolymer phases, i.e. attaining a vanishing interfacial tension. In a word, our results justify the notion that there exists a direct correlation between peculiar changes in interfacial properties and the phase transitions from 2P or LAM to the B mu E state. (C) 2013 Elsevier Ltd. All rights reserved.
语种	英语
出版者	ELSEVIER SCI LTD
WOS记录号	WOS:000317377000026
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/42242]
专题	中国科学院化学研究所
通讯作者	Guo, Hongxia
作者单位	1.Chinese Acad Sci, Inst Chem, Beijing Natl Lab Mol Sci, Beijing 100190, Peoples R China 2.Chinese Acad Sci, Inst Chem, Joint Lab Polymer Sci & Mat, Beijing 100190, Peoples R China 3.Chinese Acad Sci, Inst Chem, State Key Lab Polymer Phys & Chem, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Bai, Zhiqiang,Guo, Hongxia. Interfacial properties and phase transitions in ternary symmetric homopolymer-copolymer blends: A dissipative particle dynamics study[J]. POLYMER,2013,54(8):2146-2157.
APA	Bai, Zhiqiang,&Guo, Hongxia.(2013).Interfacial properties and phase transitions in ternary symmetric homopolymer-copolymer blends: A dissipative particle dynamics study.POLYMER,54(8),2146-2157.
MLA	Bai, Zhiqiang,et al."Interfacial properties and phase transitions in ternary symmetric homopolymer-copolymer blends: A dissipative particle dynamics study".POLYMER 54.8(2013):2146-2157.