Water confined in the pore space
has different behaviors than bulk
water, and the minerals constructing the pores will affect water properties.
In this paper, the relaxation characteristics of water filling in
the pores of calcite and silica powders (45–74 μm) at
various saturation levels are studied by a low-field nuclear magnetic
resonance instrument. Results show that water in calcite and silica
powders has different T
2 relaxation behaviors.
Based on the results of X-ray computed tomography scanning of pore
structures, contact angle measurement, and time-of-flight secondary
ion mass spectrometry analysis of surface functional clusters, this
phenomenon is ascribed to the different status of hydroxyl groups
as the interstitial hydroxyl ion because of the formation of the bicarbonate
ion by either the interaction of water with the carbonate ion or bounding
with −Si at the silica surface. Such differences lead to water
behaving differently in the pores constructed with calcite and silica
particles.