General approach to nanocomposite preparation

A novel approach to nanocomposite preparation utilizing a swelling agent, a monomer or polymer known to intercalate/exfoliate smectite clay, has allowed the preparation of several new nanocomposites. Present in small amounts, the swelling agent serves to swell the clay layers, allowing the organic matrix to be virtually any polymer. Twenty-four polymers are used in this study, varying in solubility parameter, molecular weight, and polarity. Many of these polymers do not yield a nanocomposite structure by simple melt mixing of the clay and polymer. Although some polymers are capable of partial intercalation or exfoliation without the addition of a swelling agent, addition of 2 wt% of this additive results in either complete intercalation/exfoliation or an increased percentage of nanocomposite formation, in comparison to the clay-polymer mix. The evidence of a nanocomposite structure is provided by a shift in, or the absence of, clay reflections in X-ray powder diffraction patterns.