Phase stability of Keplerate-type polyoxomolybdates controlled by added cationic surfactant

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	Phase stability of Keplerate-type polyoxomolybdates controlled by added cationic surfactant
	Fan DW(范大伟) ; Hao JC(郝京诚)
刊名	Journal of Colloid and Interface Science
	2009
卷号	333 页码:757-763
关键词	Polyoxomolybdate Self-assembly Phase transition Zeta potential Surface modiﬁcation
ISSN号	0021-9797
通讯作者	郝京诚
中文摘要	Phase stability of two nanometer-scale Keplerate-type polyoxomolybdates, (NH4)42[MoVI 72MoV 60O372(CH3- COO)30(H2O)72]·300H2O·10CH3COONH4 ({Mo132}) and MoVI 72FeIII 30O252L102·ca. 180H2OwithL = H2O/CH3- COO−/Mo2On− 8/9 ({Mo72Fe30}), can be easily achieved by controlling the concentration of a cationic surfactant, tetradecyltrimethylammonium bromide (TTABr), in aqueous solution. Precipitates and ﬂoccules were observed when the stoichiometric ratios of rTTA+/{Mo132} and rTTA+/{Mo72Fe30} were 40:1 and 90:1, respectively, which were determined by zeta potential measurements. The surface charge properties and structure morphologies of {Mo132}and{Mo72Fe30} induced by controlling cationic TTABr in aqueous solution were determined by zeta potential measurements and transmission electron microscopy (TEM) observations. {Mo132}and{Mo72Fe30} can self-assemble into supramolecular “Blackberry” structures and exist at compositions less than the stoichiometric ratios of rTTA+/{Mo132} and rTTA+/{Mo72Fe30} in aqueous solution. Above the 1:1 stoichiometric ratio of TTABr/{Mo132}orTTABr/{Mo72Fe30}, the precipitates and ﬂoccules dissolve. Dynamic laser light scattering (DLS) measurements clearly demonstrated that the Rh values have essentially no angular dependence at excess amounts of TTABr, suggesting the presence of spherically symmetric aggregates of {Mo132}and{Mo72Fe30}. Bilayer-like structures in aqueous solution were also demonstrated by TEM images. The interesting phase transition observed in our model systems of {Mo132}and{Mo72Fe30} macroanions with high chemical stability, similar shape, and masses could provide models for the understanding of more complex polyelectrolyte solutions and self-assembled soft magnetic materials and in bioapplications for highly selective adsorbents of proteins with different molecular sizes and charges.
学科主题	材料科学与物理化学
收录类别	SCI
资助信息	the NSFC (Grant 20625307);National Basic Research Program of China (973 Program, 2009CB930103)
语种	英语
WOS记录号	WOS:000265121500044
公开日期	2012-11-13
内容类型	期刊论文
源URL	[http://210.77.64.217/handle/362003/2061]
专题	兰州化学物理研究所_固体润滑国家重点实验室
推荐引用方式 GB/T 7714	Fan DW,Hao JC. Phase stability of Keplerate-type polyoxomolybdates controlled by added cationic surfactant[J]. Journal of Colloid and Interface Science,2009,333:757-763.
APA	范大伟,&郝京诚.(2009).Phase stability of Keplerate-type polyoxomolybdates controlled by added cationic surfactant.Journal of Colloid and Interface Science,333,757-763.
MLA	范大伟,et al."Phase stability of Keplerate-type polyoxomolybdates controlled by added cationic surfactant".Journal of Colloid and Interface Science 333(2009):757-763.