陶瓷泥浆触变模型的研究

本文运用结构原理法建立了陶瓷泥浆的触变模型，并通过实验对所建立的模型进行了验证。结果表明，运用该模型能成功地实际现象，在泥浆性能的定量化研究方面作了有益的探索。     

Investigation of thixotropy behavior of crude oil—Polyacrylamide emulsions

This investigation focuses on the study of the thixotropy behavior of crude oil–polyacrylamide emulsions. A wide range of crude oil and polymer concentrations were covered. Crude oil concentrations of 0–75% by volume and polymer concentrations of 0–10⁴ ppm were used. Two polyacrylamides of Alcoflood polymers, AF1235 and AF1285, were examined. RheoStress RS100 rheometer from Haake was employed to study the thixotropy behavior of crude oil–polymer emulsions. Measurements of thixotropy were conducted under the controlled rate mode. The aqueous solutions of Alcoflood polymers show thixotropy behavior. AF1235 aqueous solutions show lower hysteresis rheograms and thixotropy area than the aqueous solutions of AF1285. Polymer concentration shows strong influence on the ramp‐up and ramp‐down curves. The crude oil–polymer emulsions behave in an antithixotropy response instead of thixotropy behavior experience for the polymer aqueous solutions. The yield stress values of the crude oil–polymer emulsions increase strongly with polymer concentration for ascending and descending cycles. However, for polymer concentration of less than 1000 ppm, crude oil shows strong effects on the emulsion yield stress values for the ramp‐down cycles. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Semi‐dilute solutions of hydroxypropyl guar gum: Viscosity behaviour and thixotropic properties

Semi‐dilute solutions of hydroxypropyl guar gum (HPGG), the most widely used derivative of naturally occurring guar galactomannan, were investigated with respect to their viscosity, yield stress and thixotropy. It was found that the shear‐dependent viscosity behaviour under various HPGG concentrations, added salts and temperature could be well described by the Cross viscosity model. The zero‐shear‐rate viscosity was observed to change with HPGG concentration according to a power‐law function, and decease with the increase of temperature according to an Arrhenius‐type equation. The addition of salts (KCl and CaCl₂) lowered the zero‐shear‐rate viscosity. The HPGG solutions of high concentration showed a higher degree of thixotropy while the addition of salt lowered the thixotropic property. Copyright © 2007 Society of Chemical Industry     

Rheological Properties of Quaternary Ammonium Gemini Surfactants in Aqueous Solution

The rheological properties and time effect of a quaternary ammonium salt gemini surfactant C_n‐s‐C_n?2Br solution were measured. The rheological properties were markedly different at various concentrations of the surfactant C₁₂‐2‐C₁₂?2Br solutions. When the alkyl chain of C_n‐2‐C_n?2Br solution is 14 or 16, the rheological properties of the solution exhibit fluid dilatancy very similar to C₁₂‐2‐C₁₂?2Br solutions. However, when the length of the spacer is four or six, C₁₂‐s‐C₁₂?2Br solutions exhibit Newtonian fluid behavior and are quite different from the C₁₂‐2‐C₁₂?2Br solution. A C₁₂‐2‐C₁₂?2Br solution at a high concentration shows negative thixotropy and time dependency.     

Flow behaviour of carrot puree: modelling the influence of time,temperature and potato flakes addition

Rheological properties of carrot puree were investigated in the 1–1000 s^?1 shear rate range with the objective of modelling the influence of time, temperature and addition of potato flakes on the flow behaviour. Carrot puree exhibited a shear‐thinning behaviour that was well described by the Ostwald‐de Waele (Power Law) model with a flow behaviour index of 0.34 (±0.02) at 20 °C. The time‐dependent behaviour was characterised by a second‐order Structural Kinetic Model. The decay of the structural parameter with time was found to be independent of shear rate. The Arrhenius model was used to explain the effect of temperature in the range from 4 to 60 °C. The dry matter was increased by adding potato flakes (0–5%). A power law model (for the concentration) and the Arrhenius relationship (for the temperature) were combined to simultaneously describe the effects of temperature and concentration. This study provides essential data for equipment and process design.     

羧甲基瓜尔胶水溶液流变特性研究

研究了羧甲基瓜尔胶水溶液的流变特性,考察了羧甲基瓜尔胶浓度、温度、pH值及外加NaCl浓度对羧甲基瓜尔胶水溶液表观黏度的影响.结果表明,羧甲基瓜尔胶水溶液表观黏度随浓度的增加而增大,随温度的上升而降低,随NaCl浓度的增加而明显降低,稳定的pH值范围为6～8.羧甲基瓜尔胶水溶液具有剪切变稀特性,溶液表观黏度随剪切速率的变化可用Ostwald-Dewaele方程描述;零切黏度可由Spencer-Dillon经验公式外推得出,其与温度的关系符合Arrhenius公式.羧甲基瓜尔胶水溶液具有一定的触变性和黏弹性,黏弹性随浓度的增加而增强.图10表2参16     

防水冲稀堵漏预处理剂HSN的研制及应用

针对含水漏失层的堵漏难题,研发了防水冲稀堵漏预处理剂HSN.HSN具有pH值降低时及与钙、镁离子作用时黏度变大的独特性质.HSN在与地层水接触后,与地层水中的钙、镁离子可发生迅速反应,使溶液黏度迅速变大,并且生成具有一定弹性的不均匀网状结构,从而使堵漏材料有效滞留.煤层气井韩5 -094井在井深605m处发生失返性漏失,堵漏9次未成功,分析认为是由含水裂缝引起的,因此采用HSN溶液并配合堵漏浆堵漏,结果使用很少堵漏材料即成功封堵.     

垂直型单组分聚氨酯防水涂料的研究

合成了能够在垂直立面施工的单组分聚氨酯防水涂料,研究全新的化学增稠方式,实现产品触变性,探讨聚醚种类及比例、-NCO含量、反应温度等对产品性能的影响.结果表明,通过化学反应增稠的方式,能够实现垂直面不流淌、不流挂、可1次厚涂,涂层密实.m(聚醚二元醇):m(聚醚三元醇)=1:1.5,-NCO含量3.5%,预聚温度控制80℃左右时,可得到综合性能优异的防水涂料.     

氧化石墨烯对新拌水泥浆体流变性的影响

随着纳米材料和技术不断发展,关于氧化石墨烯对水泥基材料改性作用的相关研究越来越受到重视。在此背景下,通过Anton Paar Rheolab QC型旋转黏度计研究了氧化石墨烯对新拌水泥浆体流变性的影响,并测试了浆体静态屈服应力、动态屈服应力和黏度系数以及触变环面积。结果表明:相同氧化石墨烯掺量下,随浆体静置时间延长,低剪切速率下浆体的静态屈服应力逐渐增大;随氧化石墨烯掺量增大,浆体结构建立参数、动态屈服应力和黏度系数先增大后减小,而触变滞后环面积则呈现相反的变化趋势。     

高岭土改性玻璃钢研究

本文研究了四种高岭土对玻璃钢的性能影响。研究结果表明，加入高岭土后，玻璃钢的强度或多或少都有降低；改性314－2高岭土加量28．8％时，能赋予树脂体系触变性，可用于代替气相SiO2；高岭土930－3能使玻璃钢的马丁耐热温度提高到230℃以上。改性314－2和改性930－3高岭土可以在FRP中推广应用。