Hydrolysis and Dispersion Properties of Aqueous Y(2)Si(2)O(7) Suspensions

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	Hydrolysis and Dispersion Properties of Aqueous Y(2)Si(2)O(7) Suspensions
	Z. Q. Sun; X. W. Zhu; M. S. Li; Y. C. Zhou; Y. Sakka
	2009
发表期刊	Journal of the American Ceramic Society
ISSN	0002-7820
卷号	92 期号:1 页码:54-61
摘要	The dispersion of aqueous gamma-Y(2)Si(2)O(7) suspensions, which contain only one component but have a complex ion environment, was studied by the introduction of two different polymer dispersants, polyethylenimine (PEI) and polyacrylic acid (PAA). The suspension without any dispersant remains stable in the pH range of 9-11.5 because of electrostatic repulsion, while it is flocculated upon stirring due to the readsorption of hydrolyzed ions on the colloid surface. However, suspensions with 1 dwb% PEI exhibit greater stability in the pH range of 4-11.5. The addition of PEI shifts the isoelectric point (IEP) of the suspensions from pH 5.8 to 10.8. Near the IEP (pH(IEP)=10.8), the stability of the suspensions with PEI is dominated by the steric effect. When the pH is decreased to acid direction, the stabilization mechanism is changed from steric hindrance to an electrosteric effect little by little. PAA also has the effect of reducing the hydrolysis speed via a "buffer effect" in the basic pH range, but the lack of adsorption between the highly ionized anionic polymer molecules and the negative colloid particle surfaces shows no positive effect on hydrolysis of colloids and on the stabilization of Y(2)Si(2)O(7) suspensions.
部门归属	[sun, ziqi; li, meishuan; zhou, yanchun] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [sun, ziqi] chinese acad sci, grad sch, beijing 100039, peoples r china. [zhu, xinwen; sakka, yoshio] natl inst mat sci, nano ceram ctr, tsukuba, ibaraki 3050047, japan. [zhu, xinwen; sakka, yoshio] natl inst mat sci, wpi ctr mana, tsukuba, ibaraki 3050047, japan.;zhou, yc (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china;yczhou@imr.ac.cn sakka.yoshio@nims.go.jp
关键词	Silicon-nitride Electrophoretic Deposition Colloidal Dispersions Poly(Acrylic Acid) Hot Corrosion Molten-salt Gamma-y2si2o7 Polyethylenimine Stability Heterocoagulation
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文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/32318
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Z. Q. Sun,X. W. Zhu,M. S. Li,et al. Hydrolysis and Dispersion Properties of Aqueous Y(2)Si(2)O(7) Suspensions[J]. Journal of the American Ceramic Society,2009,92(1):54-61.
APA	Z. Q. Sun,X. W. Zhu,M. S. Li,Y. C. Zhou,&Y. Sakka.(2009).Hydrolysis and Dispersion Properties of Aqueous Y(2)Si(2)O(7) Suspensions.Journal of the American Ceramic Society,92(1),54-61.
MLA	Z. Q. Sun,et al."Hydrolysis and Dispersion Properties of Aqueous Y(2)Si(2)O(7) Suspensions".Journal of the American Ceramic Society 92.1(2009):54-61.