氧化铝陶瓷料浆流变性的研究

主要研究了氧化铝料浆的流变性能,确定了分散剂的加入量与料浆浓度的关系,测得氧化铝浓料浆为剪厚型流体,通过对浓悬浮体流变性的研究得到其稳定分散的最佳pH范围是11～12.     

陶瓷料浆稳定分散进展

本文综述了影响陶瓷料浆稳定分散的胶态理论进展,同时指出配制稳定分散陶瓷料浆的控制因素及调控措施。     

聚丙烯酸钠陶瓷料浆分散剂的研制及分散机理探讨

通过正交实验,采用先聚合后中和工艺合成聚丙烯酸钠分散剂,并借助计算机对实验结果进行二次回归分析,最优化实验配方.测试表明该分散剂对普通陶瓷料浆分散效果显著.探讨了影响合成产品分散能力的因素和分散机理.     

氮化硅料浆的触变性

研究了分散剂加入量、球磨时间、料浆固含量、料浆pH值等因素对流动曲线上触变滞回环宽度大小的影响,据此分析探讨了各因素对料浆触变性的影响。     

氮化硅料浆的流变性能

研究了分散剂加入量,球磨时间,料浆固相含量,料浆ＰＨ值对含烧结助剂α－Ａｌ２Ｏ３,Ｙ２Ｏ３的氮化硅浆的流变性能的影响。     

影响氧化铝水基料浆流变学特性的关键因素

用流变学的方法在RV-20型流变仪上研究不同条件,如:固含量、分散剂加入量、烧结助剂、增塑剂等对碱性氧化铝悬浮体的流变性的影响.结果表明:氧化铝陶瓷碱性料浆(pH＞7)在低的剪切速率(＜100 s-1)时,表现为剪切变稀.在水基料浆中添加MgO时,会发生强烈的水合反应,导致料浆失去流动性.增塑剂甘油的加入导致料浆粘度升高的幅度是有限的,不会对料浆固含量和浇铸工艺造成显著不利的影响.加入水溶性丙烯酸乳液后,在低的剪切速率下,料浆仍然呈现剪切变稀行为,随着乳液含量的增加,料浆的静态粘度逐渐增大.分散剂聚丙烯酸氨的加入量对料浆的稳定性具有显著的影响.在分散剂的加入量为固相质量的0.8%左右时,分散剂在陶瓷颗粒表面形成饱和吸附,此时料浆的稳定性达到了最佳状态.     

氧化铝粉体在硅溶胶中分散行为的研究

利用ζ电位、沉降实验、流变学测试研究了氧化铝粉体在硅溶胶中的分散行为。研究发现,硅溶胶分散的氧化铝浆料在pH=10附近沉降量低和粘度最小,表明氧化铝在硅溶胶中分散的最佳pH条件为pH=10左右。还发现氧化铝在硅溶胶中分散受硅溶胶浓度的影响较大,其资料贴度随硅溶胶浓度的增加而减小,在其质量分数为10％－15％之间达到最低;当浓度进一步增加时,其粘度呈现微小的增加。为此,本研究指出,氧化铝在硅溶胶中分散机理为静电位阻稳定,这是由于带负电荷的氧化硅胶粒在氧化铝颗粒表面形成一包覆层,增加了颗粒间的静电斥力位能和产生的一种空间斥力位能。     

氧化铝浇注料浆的老化行为

为了防止料浆老化、保护产品最终所希望的稳定性,确定悬浮液随时间的流变特性是必不可少的。     

天然鳞片石墨在水中的分散性研究

利用ζ电位、润湿性、沉降性、流变学测试研究了表面活性剂、表面包覆Al(OH)3对天然鳞片石墨在水中分散性的影响。结果表明：经过表面活性剂处理和Al(OH)3表面包覆能使石墨在水中的分散性能得以改善，石墨在水中的分散性取决于石墨与水的润湿性。     

Amphoteric water‐soluble copolymer for barium titanate slurries. I. Synthesis and dispersing ability

An amphoteric water‐soluble copolymer, polyacrylamide/[α‐N,N‐dimethyl‐N‐(3‐(β‐carboxylate)acrylamino)propyl] ammonium ethanate (PAM/DAE) was synthesized and used as a dispersion agent for BaTiO₃ particles. PAM/DAE was prepared from acrylamide and [α‐N,N‐dimethyl‐N‐(3‐(β‐carboxylate)acrylamino)propyl] ammonium ethanate in a basic condition through a free‐radical polymerization. The structure of this copolymer was verified by IR and ¹H‐NMR spectra. The dispersing effects of PAM/DAE were examined by measuring the viscosity and sedimentation of BaTiO₃ suspensions, and by analyzing the particle size. The results indicate that this copolymer could uniformly disperse the particles, and the resulting suspensions were less viscous, more stabilized, and contained powder with smaller particle size. The dispersing/stabilizing ability of PAM/DAE is close to, or slightly better than, that of a commercial dispersant, ammonium salt of poly(methacrylic acid). © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1443–1450, 2005     

SiO2微粉浆体的流变性研究

利用流变仪研究了改变SiO2微粉种类(其d50分别为0.202、3.457、5.789 um,ω(SiO2)分别为96.70%、93.64%、93.00%)、浆体中SiO2微粉的体积分数(分别为15%、20%、25%、30%)和分散剂(分别为一水柠檬酸和三聚磷酸钠)时SiO2微粉浆体流变性的差异,并定量计算了SiO2微粉浆体相应的流变参数.试验结果发现:在0-300 s<'-1的剪切采集区域内,不同条件下测得的流变曲线均符合Bingham流体模型;加入分散剂三聚磷酸钠和一水柠檬酸能明显改善SiO2微粉浆体的流变性,且两者的分散效果有所差异.     

纳米CaCO3填充环氧树脂分散技术研究

对纳米CaCO3填充环氧树脂的均匀分散技术进行了探讨。采用超声波振动和对纳米CaCO3进行硅烷偶联处理两种方法改进CaCO3在环氧树脂中的分散效果。扫描电镜观察表明，以上两种方法比普通搅拌混合效果更好，实现了纳米CaCO3在环氧树脂中的均匀分散。     

石墨分散剂的研究

本文对于石墨分散在水中润湿分散过程进行了研究,考察了多种分散剂对石墨－－水体系的影响,找出了性能良好的分散剂,并确定了最佳分散剂加入量。     

聚丙烯酸醇胺盐类分散剂分散性能的研究

选用不同的醇胺作为中和剂研究其对颜料分散性的影响。通过试验 ,其分散性不仅取决于分散剂与颜料的结合牢固 ,还与分散剂吸附态有关 ,A型吸附态可以取得较好的分散性     

阻垢分散剂YSS-94的合成及性能研究

以丙烯酸、２－丙烯酰胺－２－甲基丙磺酸和次磷酸钠为单体,水为溶剂,过硫酸铵为引发剂合成了ＹＳＳ－９４二元共聚物,系统地考察了其抑制碳酸钙、磷酸钙的沉积能力,稳定锌离子和分散氧化铁的能力,结果表明,该共聚物是一种性能优异的新型水质稳定剂。     

电解煤浆制取氢气的工艺研究

首次对我国煤炭进行了电解制氢的工艺条件探讨,用自制Pt/Ti催化电极和Pt-Ir/Ti催化电极为工作电极,分别研究了反应过程中煤浆浓度、电解温度、电解质硫酸的浓度、不同煤种、不同溶液催化剂Ce4+、Fe(CN)63-、Fe3+及Fe2+/Fe3+对电解制氢的影响。使用不同电极时电流密度相差较大,Pt-Ir/Ti电极比传统的Pt片电极对电解煤炭制氢的催化效果要好。以Pt-Ir/Ti(摩尔比1∶2)为工作电极所得最大电解制氢效率为99.7%,氢气流速为19.7 mL/(cm2.h)。Fe2+/Fe3+的联用大大提高了电解制氢的效率。阳极气体分析主要组分是CO2及少量CO,还有痕量的低沸点有机物气体,且CO2与氢气体积比为1∶(10~20),大大降低了对该方法引起温室效应的预期。     

Seeding slurries based on detonation nanodiamond in DMSO

Identification of a solvent where nanodiamond particles form stable colloids is very important for a variety of applications including seeding of a substrate for diamond film growth. Dimethyl sulfoxide (DMSO) is one of the most powerful readily available organic solvents. We demonstrated that using DMSO as a solvent for detonation nanodiamonds (DND) provides significant advantages in achieving resistance to sedimentation in colloidal suspensions for DND with positive zeta potentials. Colloidal stability of DND with negative zeta potentials in DMSO, however, is low. Using DMSO allows for the effective fractionation of a variety of DNDs including those that cannot be fractionated using DI water, for example, as a solvent. We also present seeding results using different DMSO/alcohol seeding slurry compositions. Combination of DMSO and alcohol as a seeding slurry allows removal of the solvent without damaging uniformity of the seeds after their distribution over a substrate.     

Effect of molecular weight of an anionic dispersant on the properties of BaTi4O9 slurries

The colloidal stability of BaTi₄O₉ (BT₄) aqueous suspensions with poly(acrylamide‐co‐4‐carboxylamino‐4‐oxo‐2‐butenate) (PAC) of different molecular weights at pH 9 has been investigated by means of zeta potential, adsorption, sedimentation, and particle size measurements. The results indicate that PAC could improve the dispersion of the particles from agglomeration. The resulting suspensions became more stabilized, and contained powder with smaller particle size. Consequently, the compacts with PAC exhibited better properties in terms of density and dielectric constant than those without any polymer present. The performance of PAC increased with decreasing polymer molecular weight. Clearly, PAC1 (M_w = 1.8 × 10⁴) was most effective in dispersing the BT₄ particles, and stabilizing the ceramic suspensions. This is attributed to the highest adsorption of this polymer onto BT₄ powder, and causes strongest electrostatic repulsions among solid particles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012