ORIENTED CRYSTALLIZATION OF CUSO4.5H(2)O UNDER A MONOLAYER OF A NOVELAMPHIPHILIC LIGAND, 8-HEXADECYLOXYQUINALDIC ACID

A new amphiphilic ligand, 8-hexadecyloxyquinaldic acid (HQA), has been synthesized and the characteristics of its monolayer on pure water an d on CuSO4 aqueous solution have been examined. The HQA monolayer can interact with copper ions in the subphase, and crystallization of CuSO 4 . 5H(2)O is induced under the monolayer. In order to understand the relationship between the different states of the monolayer and the ind uced inorganic crystallization, several typical states of the monolaye r were chosen in our experiment. The results show that, when the monol ayer is in the gas or liquid phase, its ability to control the oriente d crystallization is poor. However, rather than the most dense phase, the most favorable state for oriented crystallization is the one with an area per molecule A = 17.0 Angstrom(2), which could be considered a s a liquid solid phase. This is attributed to a coordination effect an d lattice matching at the inorganic/organic interface. Our research su ggests that the state of the monolayer is a very important factor duri ng the process of induced oriented crystallization.