| 초록 |
Abstract: The basal spacings of sodium montmorillonite (Na-MMT) dispersed in various solvents and monomers were measured via X-ray diffraction. Some liquids with strong hydrogen bonding(δh) groups showed little suspended Na-MMT, but liquids with medium or weak hydrogen bonding groups precipitated Na-MMT completely, this indicates that hydrogen component is an important factor for the dispersion state of natural Na-MMT in a liquid. The basal spacing expansion also depends on polar components (δp) and hydrogen bonding components (δh) of organic materials. Materials with high δh values showed expansion in the order of MeOH>EtOH>IPA>hexane>toluene>benzene, and monomers with high δp values exhibited expansion in the following order of BA>AN>MMA>ST. Since dipole-dipole interactions involved both δh and δp, liquid dipole moments were adopted to explain the expansion of Na-MMT in polymer/Na-MMT nanocomposites. Monomers with high dipole moments showed large basal spacings before polymerization and produced exfoliated polymer/Na-MMT nanocomposites, whereas those with low dipole moments showed smaller basal spacings and produced intercalated polymer/Na-MMT nanocomposites. |
