Effects of Polyelectrolyte as a Dispersant on Slip Casting of Ceramic Slurries

聚电解质作为分散剂对陶瓷浆料注浆成型的影响

• 批准号: 07651016
• 负责人: HASHIBA Minoru
• 金额: $ 1.28万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07651016/
• 关键词: slurry; slip casting; polymer dispersant; zeta-potential; viscoelastic property; dispersion stabilization; セラミックス泥漿; レオロジー; 吸着等温線; 湿潤点・流動点; 流動曲線

It is desirable in slip casting to prepare concentrated slurries whilst retaining fluidity. A polyelectrolyte as a dispersant is effective for thickening of the slurries and that polymer have a characteristic function in fluidizing slurries, other than that dispersion and stabilization. The flow point refers to the least amount of a medium (the thickening limit) required for a definite amount of powder of a start to flow. The fluidity of the slurries in the vicinity of the thickening limit was affected by a kind of dispersant, the concentration and molecular weight of dispersants and the solid loading in the slurries. The dispersion accompanied by fluidization and the limit of thickening should be related to the structure of the length extension of dispersant (the conformation of dispersant) in the adsorption layr on the ceramic particles and also to the interaction among such solid particles in the concentrated slurry. A polyelectrolyte dispersant has electrostatic effect and an addit … More ional steric effect since the polymer expands in the adsorption layr thereby exceeding the effective distance that the van der Waals attraction force operates over.An average shell volume occupied in the adsorption layr on alumina by a polyacrylic acid ammonium salts molecule (PAA) defined as the average area occupied by an adsorped PAA on alumina multiplied by the average thickness of the water layr at the limit of thickening, has been calculated from the adsorbed amount of PAA and from the flow points of alumina in the presence of PAA of different molecular weights. A steric effect of the PAA dispersant on the dispersion of alumina resulted in a flow with no yield stress. This was due to the change of the extension of PAA in the adsorption shell from a sphere to an ellopsoid with a long axis which exceeded the effective distance that the van der Waals attraction force reaches at a molecular weight for the PAA of between 10,000-20,000.It was also developed the determination method of polyelectrolyte and discussed the effects of pH changes on the conformation changes for polymers in the slurries, the adsorbed amount of polymers and the dispersion accompanied by fluidization in the presence of dispersant. Less

在粉浆浇注中，期望制备浓缩浆料同时保持流动性。作为分散剂的聚合物对于浆料的增稠是有效的，并且该聚合物在流化浆料中具有除分散和稳定之外的特征功能。流动点是指一定量的粉末开始流动所需的介质的最小量（稠化极限）。分散剂的种类、分散剂的浓度、分散剂的相对分子质量以及浆料中的固体含量对浆料在增稠极限附近的流动性有影响。流化分散和增稠极限与陶瓷颗粒上吸附层中分散剂的长度延伸结构（分散剂的构象）有关，也与浓浆中固体颗粒间的相互作用有关。聚电解质分散剂具有静电效应，添加剂 ...更多信息 聚丙烯酸铵盐分子（PAA）在氧化铝上的吸附层中占据的平均壳体积定义为氧化铝上吸附的PAA占据的平均面积乘以在增稠极限时水层的平均厚度，从PAA的吸附量和氧化铝在不同分子量PAA存在下的流动点计算出。PAA分散剂对氧化铝分散的空间效应导致无屈服应力的流动。这是由于PAA在吸附壳层中的延伸从球形变为具有长轴的椭圆形，该长轴超过了在PAA的分子量为10，000 -20时货车德瓦尔斯吸引力所达到的有效距离，研究了pH值变化对聚合物构象变化的影响，建立了聚合物构象变化的测定方法，浆料、聚合物的吸附量和在分散剂存在下伴随流化的分散。少

项目成果

Itoh et al.: "Extension of polyacrylic acid ammonium salto in the adsorption layr to fluidize alumina slurries" J.Mater.Sci.31. 3321-3324 (1996)

Itoh 等人：“吸附层中聚丙烯酸铵盐的延伸使氧化铝浆料流化”J.Mater.Sci.31。

Itoh et al.: "Extension of polyacrylic acid ammonium salts in the adsorption layer to fluidize alumina slursies" J Mater. Sci.31. 3321-3324 (1996)

Itoh 等人：“吸附层中聚丙烯酸铵盐的延伸使氧化铝浆液流化”J Mater。

M.ITOH et al.: "Extensions of polyacrylic acid ammonium salts in the adsorption layer to fluidize alumina slurries" J.Mater.Sci.31. 3321-3324 (1996)

M.ITOH 等人：“吸附层中聚丙烯酸铵盐的延伸使氧化铝浆料流化”J.Mater.Sci.31。