Effects of Tx-100-SDS on crystal growth of calcium carbonate in reverse microemulsion solution

Syntheses of CaCO3 crystals in reverse microemulsion solutions containing 1-(1,1,3,3-tetramethylbutyl)-4-hydroxypolyethoxybenzene (Tx-100), sodium dodecyl sulfate (SDS) and their equimolar mixture were carried out at room temperature respectively. The crystal phase of CaCO3 is changed from calcite at low concentrations to vaterite at high concentrations of SDS and Tx-100. From rods at low concentration to olivary spheres at high concentration, SIDS can influence the morphology of CaCO3 significantly, while almost no such effect for Tx-100. Hollow spheres, olivary spheres and even two fused olivary spheres of CaCO3 were produced at different concentrations of Tx-100-SDS, and the variation of crystal phase is opposite to that in the presence of SDS or Tx-100 alone. The effects of interaction of SDS with Tx-100 on morphology and crystal phase of CaCO3 were discussed. It was estimated to put forward that the formation of hollow CaCO3 crystals was caused by the collaborating actions of SDS template and TX-100 inhibition.