Understanding the dynamic pore wetting by ¹H LF-NMR characterization. Part 1: Effect of dynamic viscosity of liquid

Dynamic pore wetting is significant for understanding the wetting behavior of fluid in porous materials. This study of dynamic pore wetting includes two parts (Part 1 and Part 2). The first paper (Part 1) of this study mainly investigated the effect of liquid viscosity on dynamic wetting of pores of different sizes in hydrophilic and hydrophobic active carbon by a H-1 low-field nuclear magnetic resonance (H-1 LF-NMR). In order to fully understand the role of physical properties of liquids in dynamic pore wetting, the mechanism of surface tension affecting the pore wetting process was revealed in the second paper (Part 2). In Part 1, the feasible of H-1 LF-NMR characterizing the dynamic pore wetting process was firstly discussed by comparing the measured results of H-1 LF-NMR and weighting method. The quantitative model between dynamic viscosity and pore wetting percentage was built and the Crispation number of liquids in the pores of different sizes were calculated to reveal the degree of interface deformation inside the pore. As the viscosity increased, the pore wetting percentages in the hydrophilic and hydrophobic samples were decreased significantly. The decreasing degree of pore wetting percentage was in the order: transition pores > micropores > mesopores. The correlation between the viscosity and 60 min pore wetting percentage was the first-order linear decreasing except for mesopores. Compared with the hydrophobic sample, the 60 min pore wetting percentages (except for mesopores) in the hydrophilic sample had a better linear decreasing relationship with the Crispation number.