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碳化硅浓悬浮体的分散特性和流变性研究 总被引:19,自引:6,他引:19
通过对碳化硅粉体在有机单体介质中的Zeta电位,分散剂用量和浓悬浮体的粘度等的测试及其沉降试验,详细研究了粒径分布较宽的碳化硅粉体(0.2-250μm)的胶体分散特性,沉降行为以及浓悬浮体的流变行为。结果表明,选用适量的分散剂四甲基氢氧化铵可使SiC颗粒的Zeta电位绝对值提高近20mV,调整浆料pH至11.9附近可制备出固相体积分数高达70%的SiC浓悬浮体。该浓悬浮体中粗细SiC颗粒间能达到一稳定的分数,悬浮粒子不会产生明显地沉降,其流变行为符合Quemada模型。 相似文献
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《陶瓷》2018,(11)
高性能陶瓷具有高强、高硬、耐磨、耐高温、耐腐蚀、稳定性好等优异的物理和化学性能,具有很广的应用范围,逐渐成为一类具有发展潜质的新型材料。在制备高性能陶瓷的过程中,陶瓷材料制备技术发挥的作用越来越重要。笔者采用分散剂失效直接凝固注模成形方法(DCC),使用三聚磷酸钠(STPP)作为分散剂,利用三聚磷酸钠在高温及中性pH值环境下水解的性质,使氧化铝悬浮体发生原位固化,研究三聚磷酸钠添加量对氧化铝悬浮体zeta电位及粘度的影响,固相含量对氧化铝陶瓷悬浮体粘度的影响,温度对氧化铝陶瓷悬浮体粘度的影响等方面。通过实验,获得适宜的分散剂添加量和pH值范围,从而制备出分散性良好的氧化铝陶瓷悬浮体,进而获得力学性能最好、微观结构最均匀时对应的固化温度、固化时间,总结出最适宜的氧化铝陶瓷制备方案,从而获得高性能氧化铝陶瓷样品。 相似文献
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本文以氧化铝陶瓷为例,研究探讨了凝胶注模成形工艺中制备低粘度、高固相含量浓悬浮体的关键技术,讨论了分散剂因素对粘度的影响和不同固相含量对坯体强度的影响。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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杀虫磺缓释剂杀钉螺试验报告 总被引:1,自引:0,他引:1
杀虫磺缓释剂浸杀成螺、幼螺、螺卵效果好,现场应用缓释片63克/米^2,半年后活螺平均密度下降93.2%,春季施药1次,可达到控制当年钉螺的扩散。 相似文献
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为实时监控化学-酶法制备氰氟草酯反应过程,建立了一种该体系中氰氟草酯的RP-HPLC的检测方法。采用SymmetryC18柱(5μm,4.6 mm i.d.×150 mm),以V(甲醇)∶V(水)=80∶20为流动相,流速为1.0 mL/min,紫外检测波长为282 nm,柱温为30℃,进样量为20μL。氰氟草酯在5.0~1000.0 mg/L范围内线性良好,相关系数达到0.9999,检出限为1.0 mg/L,相对标准偏差为0.58%(n=5),加标回收率在92.3%~101.5%之间。 相似文献