- 學位論文
有機添加劑對羥基化鈦酸鋇水系漿料分散性質之影響
Effects of Organic Additives on the Dispersion of Hydroxylated BaTiO3 in Aqueous Suspensions
摘要
由本實驗室之前期研究結果指出利用雙氧水改質鈦酸鋇粉末可在鈦酸鋇表面上衍生出羥基。以羥基化鈦酸鋇取代未改質鈦酸鋇的使用，可有效避免同時含有黏結劑聚乙烯醇(PVA)與助熔劑氧化硼(B2O3)之水系漿料常見的膨脹性流變行為；這是由於PVA與B2O3之間的膠聯反應所致。羥基化鈦酸鋇的取代使用可使該水系漿料從原本不利於後續塗佈製程之膨脹性流體轉變為利於塗佈之假塑性流體。另一方面，已知聚丙烯酸銨(PAA-NH4)為水系鈦酸鋇漿料常用的分散劑；因此本論文亦將探討PAA-NH4與不同羥基化程度之鈦酸鋇的交互作用，及對不同羥基化鈦酸鋇之水系漿料分散性質的影響。PAA-NH4與PVA於各種羥基化鈦酸鋇粉末上之競爭吸附行為對水系漿料分散性質的影響，亦於本論文中有深入討論。
並列摘要
In our previous study, we have reported that the –OH can be efficiently derived on the particle surface of BaTiO3 by treatment with hydrogen peroxide (H2O2). With the use of hydroxylated instead of as-received BaTiO3, the dilatancy of the as-prepared aqueous slurry caused by gelation between the binder, poly(vinyl alcohol) (PVA), and the sintering agent, boron oxide (B2O3), is efficiently reduced. For the suspension of as-received BaTiO3, the dilatant rheology due to the interaction of PVA and B2O3 is not suitable for tape-casting. By using hydroxylated BaTiO3, shear-thinning behavior can be obtained. On the other hand, we know that the ammonium salt of poly(acrylic acid) (PAA-NH4) has been commonly used as a dispersant to stabilize aqueous BaTiO3 slurries. In this research, the interaction between PAA-NH4 and hydroxylated BaTiO3 has been studied and its effect on the dispersion behaviors of as-prepared suspensions has been mentioned as well. Furthermore, the dispersion property caused by competitive adsorption of PVA and PAA-NH4 on hydroxylated BaTiO3 has also been discussed.