SELF-CONSISTENT-FIELD CALCULATIONS OF INTERACTIONS BETWEEN CHAINS TETHERED TO SPHERICAL INTERFACES

Self consistent mean field (SCF) theory is used to investigate the str ucture of and interactions between layers of polymer chains tethered t o a spherical. interface. Traditional methods have combined flat geome try results with the Derjaguin approximation to calculate the interact ion potentials between curved surfaces, leading to a great overestimat ion of both the range and steepness of the pair interaction potential. We have improved upon this approach by utilizing the chain configurat ional statistics from the curved geometry with a modified Derjaguin ap proximation to calculate pair interaction potentials. By varying the c ore radius, the degree of polymerization, and the tethering density in an athermal solvent, the tethered layer assumes structures ranging fr om those in star polymer systems to planar polymer blushes. The intera ction potentials are found to be strictly repulsive with varying degre es of range and steepness. These changes in the interaction potential are related to changes in the tethered layer structure. The results ar e also compared with those from scaling theories. The range of the int eraction potential generally correlates with the layer thickness predi cted from scaling theory. The functional form of the interaction poten tials does not follow previously proposed forms.