A Study of the Use of Novel Self-ordering Functionalized Polymers to Control Crystal Growth

In this research, the ability of a series of novel oligomeric organic species to control the nucleation and growth of inorganic crystals was investigated. The issues under consideration were (i) the relative hydrophobicity which might be programmed into a polymer; (ii) the impact of metal binding, or bridging on polymer activity in crystallization; (iii) the mode of polymer self organisation. An homologous series of alkyl-substituted, sulfonated calixarenes were used to probe these issues. The ability of a metal cation to either bridge adjacent calix[4]arenes, or to adsorb into the molecular cavity, impacted the interaction of these molecules with nascent crystals. Selective and specific adsorption behaviours were revealed by the expression of smooth, well defined faces in crystal equilibrium morphology. When the relative hydrophobicity was high (increased molecular weight of alkyl-substituent), these compounds segregated at the gas/liquid interface and, as a consequence of cation-induced ordering, induced the oriented nucleation of crystals. This study has revealed that, in addition to polymer-crystal epitaxial relationships, a tuneable range of chemical characteristics can be programmed into polymeric substrates which are used to control nucleation and growth. © 2006 Materials Research Society.