N. Gnanapragasam et al., MICROSTRUCTURAL CHANGES IN SAND-BENTONITE SOILS WHEN EXPOSED TO ANILINE, Journal of geotechnical engineering, 121(2), 1995, pp. 119-125
Bentonite was exposed to aniline through batch experiments and flexibl
e wall conductivity tests. The mineralogy and microstructure of the sa
mples were studied using X-ray diffraction, infrared spectroscopy, sca
nning electron microscopy, and mercury intrusion porosimetry, before a
nd after aniline exposure. Results indicated that the mineralogical st
ructure of the clay mineral was unaffected by the exposure to aniline,
despite evidence that aniline adsorbed onto bentonite upon contact. T
ests on sand-bentonite composites showed that the sample with a larger
fraction of clay had a greater proportion of fine pores (<50 mu m), t
hus a lower conductivity to aniline. This is attributed to the phenome
non of the two phase immiscible flow. The conductivity of sand-bentoni
te composites to aniline appears to be controlled by the soil's pore s
tructure; the amount of bentonite controls the pore size distribution
of the sample.