Wafaa S.Hegazi
,
Eisa E.Hekal
,
Essam A.Kishar
材料科学技术（英文）
The effect of addition of Zn, Cu, Pb and Cr chlorides as admixtures on the hydration reaction of the system 3CaO•Al2O3-gypsum with molar ratio 1:3 was studied. Different ratios of each salt were used, namely 0.5%, 2% and 4% by weight of the solid mixture. Hydration reaction was carried out at 35℃ for various time intervals from 0.5 h to up to 7 d. Hydration rate of the system 3CaO•Al2O3-CaSO4•2H2O in absence and presence of different salts was studied via the determination of the combined water contents. X-ray diffraction analysis showed that the ettringite was the only hydration product formed in the different mixes. The hydration products were investigated by scanning electron microscopy (SEM) and thermal gravimetric analysis. The results indicated that the rate of formation of ettringite and its microstructure depend on the admixture and its dosage.
关键词:
Tricalcium aluminate
,
null
,
null
,
null
徐海峰
,
刘宝林
,
郝保同
,
周国燕
低温物理学报
利用差示扫描量热仪（DSC）研究了羟基磷灰石（HA）纳米微粒对丙三醇溶液冻结过程中水合性质及玻璃化性质的影响．实验结果表明在中高浓度HA纳米颗粒对溶液水合性质影响显著．与未加纳米颗粒的溶液相比，溶液结晶量减少，未冻水含量增大．在较低浓度溶液中，加入纳米颗粒后玻璃化温度变化不明显，但反玻璃化温度明显升高；当溶液浓度达到60％，加入纳米颗粒后玻璃化温度才有明显的升高趋势，并且玻璃化温度与熔融温度的间距缩短幅度很大．种种结果表明纳米颗粒对实现低温保护剂溶液玻璃化是有利的．
关键词:
纳米颗粒
,
水合性质
,
结晶量
,
玻璃化
,
反玻璃化
,
DSC
Essam A.Kishar
材料科学技术（英文）
The hydration reaction of a mixture of tricalcium aluminate (C3A) and gypsum with the molar ratio of 1:3 was carried out at room temperature and a water/solid ratio of 4.0. The hydration was carried out in presence of 0, 1 and 3% stearic acid and the mixes were designated as A, B and C, respectively. Ettringite was the only hydration product formed in the presence and absence of stearic acid. Phase composition, microstructure, infra-red analysis as well as degree of hydration were carried out for the different hydration mixtures. The rate of ettringite formation in the presence of 3% stearic acid was accelerated during the first half hour of hydration, and then retardation was occurred. In the presence of 1% stearic acid the ettringite formation was accelerated first till 3 days, then retardation was observed at later hydration ages.
关键词:
Stearic acid
,
null
,
null
