The theories of ion group aggregation in ionomers
Polimery 1997, No 9, 532
A review of the following theories: (i) Eisenberg shows the maximum size of a spherical multiplet, 8 ion pairs or less, to be determined by the surface areas and volumes of the participating chemical species; cluster's ion-pairs number is correlated with the spacing of ionic groups along the chain, density, dielectric constant, end-to-end rms length of polymer chain, ion size, th eaverage multiplet size above T a and with a constant related to cluster geometry, (ii) Foreman's lattice-based statistical-mechanical theory predicts the number m of repeat units percluster, m being assumed to be identicalf or each cluster and each cluster assumed to form from a central repeat unit and its nearest neighbors, (iii) Dreyfuss theorizes about charge clustering based on strong electrostatic interactions producing multiplets of charges that build a kind of structure with the geometry allowing for the presence of a polymeric material. The resulting cluster is independent of charge concentration; large cations produce larger clusters, (iv) Nyrkova et al. studies the microdomain structure in block copolymer melts with short blocks A, which attract each other, separated by long blocks B. As the temperature is lowered, a new „superstrong segregation regime” emerges, in which chains A become completely extended within the micelles and steric restrictions on chain conformation become important in the micelles.