Using numerical self-consistent field (SCF) calculations, we investigate the interactions between two closely spaced surfaces and the surrounding polymer melt. Short chains (surfactants) are terminally anchored to each of the surfaces. The coated substrates model organically modified clay crystallites (sheets). Through the calculations, we vary the characteristics of the surfactants and polymers to isolate conditions that drive the polymer to penetrate the gap between the surfaces. We also consider the effect of employing end-functionalized chains to promote the dispersion of bare clay sheets within the polymer matrix. We find that this scheme provides a robust method for exfoliating the sheets. To consider this case in greater depth, we develop an analytical SCF theory to model the interactions among the functionalized chains, nonfunctionalized polymers, and the clay sheets. The results from the numerical and analytical SCF models show good agreement on the behavior of the system. The results indicate that the optimal polymeric candidates for creating stable exfoliated composites are those that would constitute optimal steric stabilizers for colloidal suspensions.

We use self-consistent-field calculations and scaling arguments to determine the behavior of AB diblock copolymers that are tethered to a surface. While the surrounding solution is assumed to be a poor solvent for both components, the B block is considered to be less soluble than the A. The solvophobic interactions within the system drive the chains to self-assemble into micelles that have an “onion-” or “garliclike” structure. The specific morphology and dimensions of the micelles depend on the relative block lengths and whether the chains are grafted by the more or the less soluble component. At sparse grafting densities, the layer contains an ordered array of such micellar structures and the film forms a distinct pattern. The size and spacing of the patterns can be manipulated by varying the molecular weights of the copolymers. Thus, the results provide guidelines for fabricating well-defined patterned films.

We combine a density functional theory (DFT) with a self-consistent field model (SCF) to calculate the phase behavior of thin, oblate colloidal particles that are coated with surfactants and dispersed in a polymer melt. These coated particles represent organically modified clay sheets. By integrating the two methods, we can investigate the effect of the surfactants' characteristics (grafting density F gr and length Ngr) and the polymer-surfactant interaction energy on the polymer-clay phase diagram. Depending on the values of these critical parameters and the clay volume fraction, φ, the system can be in an isotropic or nematic phase (which corresponds to an exfoliated composite). The system can also form a smectic, crystal, columnar, or "house-of-cards" plastic solid, as well as a two-phase (immiscible) mixture. Using this model, we isolate conditions that lead to the stabilization of the homogeneous, exfoliated phases (the isotropic and nematic regions) and to the narrowing of the immiscible two-phase regions.

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