Colloid Polym Sci (2006) 284: 1345–1349 DOI 10.1007/s00396-006-1474-y SHORT COMMUNICATION

Control on shape, porosity and surface hydrophilicity of hematite particles by using polymers Abstract The shape, porosity, and surface hydrophilicity of hematite particles formed from a forced hydrolysis reaction of acidic FeCl3 solution were controlled by using a trace of polymers (0.001 and 0.003 wt%). The spherical particles were produced on the systems with polyvinyl alcohol (PVA) and poly-aspartic acid (PAS). In the case of polyacryl amide (PAAm), slightly small spherical particles were precip-itated at 0.003 wt%. However, polyacrylic acid (PAAc) and poly-γ-glutamic acid (PGA) gave ellipsoidal particles. This morphological change on hematite particles depended on the order of functional groups of polymers as –OH<–CONH2<–COOH<–COOH and C=O, corresponding to the order in extent of polymer molecules for complexation to Fe3+ ions and ad-sorption onto particle surface. Ac-companying this order, the hematite particles produced were changed from less porous to microporous. On the other hand, only the system with 0.003 wt % of PAAm produced meso-porous hematite particles. Choosing the kinds of polymers also controlled the ultramicroporosity and surface hydrophilicity of the particles