Microdynamic Properties of Pore Water in Compacted Quartz Particles
The physical properties of soil are affected by soil-water interaction,which makes pore water in soil has a completely dif-ferent physical state from that of free water.As one of the most abundant minerals in the crust of the Earth,quartz widely exists in many kinds of rocks and soils.The interaction between quartz particles and water greatly affects the engineering characteristics of rocks and soils.To study the interaction between quartz paticle and water,nuclear magnetic resonance technology was used to detect the spin lattice relaxation time T1 distribution curves at different temperatures and the T1-transverse relaxation time T2 correlation spectra at room temperature for unsaturated compacted quartz particles.Through the analysis of T1/T2 distribution curve,it is found that the T1/T2 ra-tio at the peak point is about 6.31.With Bloembergen-Purcell-Pound(BPP)model,the rotational characteristic time of pore water molecules in unsaturated quartz sample was calculated which was much longer than that of free water,indicating that the mobility of pore water in sample was greatly depressed.Using Korb model,the characteristic residence time and affinity of adsorbed water on the surface of quartz particles were calculated.The results show that the water molecules move 4.2 × 109 steps on the sand surface before leaving the quartz surface,indicating that the quartz particle has a large hydrophilic or binding property to water molecule.The varation of T1 distribution curve with temperature was analyzed based on Arrhenius theorem.It is found that the adsorption activation energy of surface adsorbed water on quartz particle is 26.8 kJ/mol,which is much higher than that of surface adsorbed water on clay particles.The result indicates that the binding effect of quartz particles on water molecules is greater than that of clay particles.This is mainly be-cause the a large number of hydrogen bonds between silanol group on the surface of quartz particles with the adsorbed water,which makes the quartz particles have a great binding effect on the adsorbed water on the surface.
nuclear magnetic resonance(NMR)quartzsoil-water interactiontemperature
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维普
