Nanocomposites based on layered silicates and epoxy resins: Measurement of clay dispersion and exfoliation using TEM, solid-state NMR, and x-ray diffraction methods

摘要

In an epoxy/layered silicate nanocomposite containing different organically modified layered silicats, the effect of various organic modifications and the layered silicate content on the layer distances are investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD) measurements, and 1H solid-state NMR. TEM micrographs were evaluated using a semi-quantitative method. The effect of paramagnetic impurities present in the clay is used to obtain overall sample information related to the degree of exfoliation by ~1H solid-state NMR. A new model for determination of the degree of exfoliation by proton longitudinal relaxation rate measurements is developed.