Investigation of the elastic properties of star polymers in semi-infinite space

Abstract We performed investigation of the elastic properties of three-armed, four-armed and five-armed star polymers in a semi-infinite space confined by a single wall with different boundary conditions and calculated Pincus force in the above mentioned cases. Calculations were carried out for three, four and five armed star polymers anchored (or grafted) to the substrate by one or two arms. Besides, the case of freely placed star polymers with different number of arms in semi-infinite space also was analyzed. The obtained results indicate that the Pincus force is affected by the number of arms anchored to the surface. For star polymer with center near the surface, the Pincus force is almost twice higher for the case of two attached arms to the substrate than for one attached arm. This difference increases as the distance of the star center from the wall increases. The results for the Pincus force agree with those obtained for the linear polymer chain previously, but have a larger value. Besides, we observe that the polymer topology have influence on the Pincus force value. The obtained results are interesting from scientific and practical point of view, because of their potential use in the production of paints, varnishes and functional materials. Star polymers can be used as viscosity modifiers, e.g. in engine oils, in cosmetics, and to increase the flexibility of the functional materials as well as drug or gene transporters.