A study of the adsorption of acyclic polyols on hydrated alumina

The adsorption of ten selected C3, C4, C5 and C6 acyclic polyols on hydrate d alumina, under Bayer liquor-like conditions, has been studied. It is foun d that adsorption is particularly sensitive to the polyhydroxy configuratio n and that it parallels the trends observed for polyol complexation with me tal cations and oxyanions. In particular, adsorption increases with increas ing numbers of vicinal hydroxy groups; threo-threo sequences promote adsorp tion whilst erythro-erythro sequences have little effect. A strong correlat ion is found between adsorption and the degree of gibbsite crystallisation inhibition reported for these compounds. Their effects on gibbsite morpholo gies in relation to mechanisms of crystal growth inhibition are discussed. (C) 1999 Elsevier Science B.V. All rights reserved.