Combined Influence of Organic Additives on Growth Morphology of Calcium Carbonate

The influence of organic additives, β-cyclodextrin, HEDTA, L-aspartic acid and L-glutamic acid on crystal growth of calcium carbonate via vapour diffusion method has been investigated. In the absence of additive, regular rhombohedral calcium carbonate crystal habit resulted. Whereas in presence of additive, calcite with truncated, aggregated rhombohedral sub crystals and elongated hexagonal morphologies resulted. The obtained calcium carbonate phases were characterized by SEM, Powder XRD and FT-IR. key words: Biomineralisation, Calcium carbonate, β-cyclodextrin, HEDTA, L-glutamic acid, L-aspartic acid. it is possible to synthesize different polymorphs of calcium carbonate using dicarboxylic acids such as malonic acid, succinic acid etc as templating agents13-14. Another polycarboxylate was employed to synthesize calcite-micro trumpets14-16 which closely mimic the coccoliths of an unicellular algae, Discosphaera tubifera. In nature, living organisms use a organic matrix containing mixed functionalities for controlling the growth, size and morphology of biominerals. Hence we have attempted to investigate the influence of mixed additives such as β-cyclodextrin (β-CD), N-(2-hydroxyethyl) ethylene diamine-N,N’,N’-triaceticacid (HEDTA), L-aspartic acid (L-ASP) and L-glutamic acid (L-GLU) (Scheme 1) on growth morphology of calcium carbonate and reported in this paper. 1560 KURRA & MUKKAMALA., Orient. J. Chem., Vol. 29(4), 1559-1563 (2013) Scheme 1: (a) β-cyclodextrin (b) N-(2-hydroxyethyl) ethylene diamine-N,N’,N’-triaceticacid (c) L-aspartic acid (d) L-glutamic acid