研磨碳酸钙涂层材料的渗吸特性与分析研究

Study on Spontaneous Imbibition of Paper Coating Materials Prepared with Ground Calcium Carbonate

针对研磨碳酸钙(GCC)纸张涂层材料的渗吸特性及经典的Lucas-Washburn(LW)渗吸模型,对材料的渗吸特性进行了实验测试,揭示了材料的渗吸性能。结果表明,涂层材料渗吸量与渗吸的根时间(t1/2)服从线性关系,但是出现了实验渗吸分区现象(即渗吸被分为两个阶段),与经典的LW渗吸机制相矛盾,因此经典的LW渗吸在解释涂层材料渗吸时仍存在一定的缺陷。基于渗吸实验的分区现象,考虑材料粗糙表面的润湿行为及液膜平滑效应,对实验渗吸现象进行了科学的解释,探究并分析了形成渗吸分区的本质原因。因此在开发具有特定渗吸特性的涂层材料时,材料本身的粗糙表面或孔墙的粗糙度应是重点关注的因素之一。

Aiming at the spontaneous imbibition features of paper coating materials prepared with ground calcium carbonate（ GCC） and the classical Lucas-Washburn（ LW） imbibition model,the imbibition characteristics of paper coating materials was measured and disclosed by a gravimetric test method. The experimental results showed that although there was a linear relationship between the imbibitions amount and the imbibition root time,a separated imbibition phenomenon（ two separated imbibition rate at different stages） was also shown sufficiently which contradicted with LW imbibition mechanism. Therefore,the classical LW imbibition theory still had some limitations to explain the imbibition characteristics of paper coating materials. According to the separated imbibitions phenomenon,the experimental results were further explained by considering the wetting behavior on roughness surface and a smooth effect of liquid film arising from capillary condensation. And the essence reason for this physical separated imbibition was also explored and discussed finally. Hence,the roughness surface and pore wall rugosity should be considered as one of important factors when developing a novel coating material with specialty imbibition performance.