Ultra high purity CaCO3 whiskers derived from enhanced diffusion of carbonate ion from larger liquid-gas interface through porous quartz stone

Larger liquid-gas interface area during carbonation process for preparing high purity aragonite CaCO3 whiskers by using porous quartz stones was developed. Plenty of open pores ranging from 0.02 to 0.20mm inside the porous quartz stones could disperse CO2 gas in Ca(OH)2 suspension into tiny bubbles with the average diameter ranging from 0.28 to 3.05mm, and large liquid-gas interface area ranging from 3571.4 to 327.9mm2 were achieved, respectively, which enhances diffusion effect of CO2 molecule and uniformity of carbonate ion in system. Thus uniform and low supersaturation is obtained, improving the growth of CaCO3 whiskers. The prepared CaCO3 whiskers show the highest purity of 99.7%. The formation mechanism of ultrahigh purity CaCO3 whiskers are also studied in detail. Then the prepared CaCO3 whiskers were introduced into PVC matrix to study its effect on tensile strength of PVC, and results show that the tensile strength has been enhanced by 46.4% with 5wt% whiskers. This method provides an effective way to enhance the performance of inorganic crystals.