Barale M, Lefèvre G, Carrette F, Catalette H, Fédoroff M, Cote G
LECA, CNRS, ENSCP, Université Paris 6, 11 rue Pierre et Marie Curie, 75005 Paris, France.
J Colloid Interface Sci. 2008 Dec 1;328(1):34-40. doi: 10.1016/j.jcis.2008.09.007. Epub 2008 Oct 1.
Zetametric measurements on suspensions of oxide particles (cobalt ferrite, nickel ferrite, and magnetite) representative of corrosion products from primary circuits of pressurized water reactors were performed at 25 and 70 degrees C in the presence of lithium and borate species. No effect of lithium ions was observed. Borate species cause a decrease of the isoelectric point (IEP), attributed to the sorption of borate as a negative complex MOB(OH)3(-). A predictive model based on thermodynamic calculations (2-pK and diffuse layer models) of the surface acidity constants from the data of acid-base titrations combined with an empirical relationship between the surface potential Psi 0 and the zeta potential determined by zetametry was developed. A whole set of parameters valid at 25 degrees C, in a range of ionic strength between 10(-4) and 10(-2) molL(-1) and in a range of pH between 4 and 8, was determined for this model. Increase of temperature to 70 degrees C in the presence of borate results in a decrease of IEP for cobalt ferrite and an increase of the IEP for nickel ferrite.
在25℃和70℃下，在锂和硼酸盐存在的情况下，对代表压水反应堆一回路腐蚀产物的氧化物颗粒（钴铁氧体、镍铁氧体和磁铁矿）悬浮液进行了Zetametric测量。未观察到锂离子的影响。硼酸盐会导致等电点（IEP）降低，这归因于硼酸盐以负络合物MOB(OH)3(-)的形式吸附。基于酸碱滴定数据对表面酸度常数进行热力学计算（2-pK和扩散层模型），并结合表面电位Ψ0与通过Zetametry测定的zeta电位之间的经验关系，开发了一个预测模型。确定了该模型在25℃、离子强度在10(-4)至10(-2) molL(-1)范围内以及pH在4至8范围内有效的一整套参数。在硼酸盐存在的情况下，温度升高到70℃会导致钴铁氧体的IEP降低，而镍铁氧体的IEP升高。
