Hołysz Lucyna, Chibowski Emil, Szcześ Aleksandra
Department of Physical Chemistry, Faculty of Chemistry, Maria Curie-Skłodowska University, 20-031 Lublin, Poland.
Water Res. 2003 Aug;37(14):3351-60. doi: 10.1016/S0043-1354(03)00159-3.
Static magnetic field (MF) effects on the properties of freshly precipitated calcium carbonate have been investigated in the presence of impurity ion Mg(2+), Fe(2+), or SO4(2-). One or both solutions, CaCl2 and Na2CO3, were exposure to MF (0.5T) for 20min at 20 degrees C. Then calcium carbonate was precipitated and zeta potential, pH and light absorbance (lambda=543.3 nm) were measured. The same parameters were also determined for the reference systems in which the solutions were not MF-treated. It was found that in all the systems tested MF effects as determined by the above mentioned parameters had appeared. They depended on the kind of the impurity ion present, as well as on which solution, CaCl2, Na2CO3 or both, MF interacted. For example, if Mg(2+) ion was present in CaCl2 solution, the largest shift in the zeta potential toward higher positive values was observed if Na2CO3 was MF-treated (e.g. from 2 to 12mV) and the same was true as for the maximum in the light absorbance and the pH increase. Interestingly, if (CaCl2 + Mg(2+)) was MF-treated pH of the slurry had decreased. Moreover, a correlation between above mentioned MF effects and the entropy of hydration of the ions has also been found. This points to the changes in the hydrating water structure caused by magnetic field.
在杂质离子Mg(2+)、Fe(2+)或SO4(2-)存在的情况下，研究了静磁场（MF）对新沉淀碳酸钙性质的影响。将CaCl2和Na2CO3中的一种或两种溶液在20℃下暴露于MF（0.5T）中20分钟。然后沉淀碳酸钙，并测量zeta电位、pH值和吸光度（λ=543.3nm）。对于未进行MF处理的溶液的参考体系，也测定了相同的参数。结果发现，在所有测试体系中，由上述参数确定的MF效应均已出现。它们取决于存在的杂质离子的种类，以及MF作用于哪种溶液，CaCl2、Na2CO3还是两者。例如，如果CaCl2溶液中存在Mg(2+)离子，当Na2CO3进行MF处理时，观察到zeta电位向更正的值有最大的偏移（例如从2mV到12mV），吸光度最大值和pH值增加的情况也是如此。有趣的是，如果（CaCl2 + Mg(2+)）进行MF处理，浆料的pH值会降低。此外，还发现了上述MF效应与离子水合熵之间的相关性。这表明磁场导致了水合水结构的变化。
