Compressibility of a "tunable" clay-polymer composite

"Tunable" clay-polymer composites are designed to be modifiable in-situ through controlled manipulation of interparticle/interlayer spacings via the surrounding fluid chemistry. This study explores the one-dimensional consolidation behavior of "tunable" clay-polymer composites in low and high ionic concentration solutions. Both low and high ionic concentrations were selected to promote polymer molecule expanded and coiled conformation, respectively. Oedometer tests were carried out on pre-consolidated specimens derived from slurries (both composite and pure clay). Also, bender elements were employed to measure shear wave velocities during consolidation. A comparison between the resulting compression curves and shear wave results indicate that as ionic concentration increases, the coefficient of consolidation, compression index, swell index, and shear wave velocity of the composite increase compared to pure clay. These results are consistent with coiled conformation of the responsive polymer.