Particle Engineering of Gypsum Through Templating with Starch

The conversion of CaSO4·0.5H2O to CaSO4·2H2O (gypsum) is great importance industrially, being the reaction behind plasterboard production and setting medical plasters. This hydration process inherently slow, ensure that it occurs on a practical timescale, “seeds” gypsum are typically added accelerate reaction. seeds used in industry mostly produced by milling quarried gypsum, resulting huge variations their accelerant properties between batches. Here, we develop bottom-up prepare with tightly defined morphology, using starch as templating agent during precipitation from water/ethanol mixtures. When thereby generated dried, they tend aggregate, which results diminished properties. (or setting) time can be markedly reduced if these aggregates broken up suspended liquid medium. indicates directly adding suspension product an industrial line could powerful way However, use ethanol seed synthesis precludes this (because would halt reaction). Therefore, direct one-step involving evaporation was developed produce water no present. resultant “liquid seeds” highly potent accelerating CaSO4·2H2O, shorter times than commercial standard accelerant.