Collect. Czech. Chem. Commun. 1991, 56, 1253-1262

Effect of precipitation and aging on porous structure of aluminium hydroxide. I. Statistical treatment of experimental data

Josef Roček, Jindřich Weiss and Květuše Jirátová

Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6-Suchdol


The analysis of variance (ANOVA) was used to test the effect of changes of temperature and pH of precipitation, the time of aging and the addition of surfactants on the porous structure of dried aluminium hydroxide (containing sulphate ions). Changes in precipitation temperature effect the structure of samples, the most pronounced effect being observed in the region of large and small pores. The less distinct effect is exerted by pH of precipitation which affects especially small pores. The time of aging up to 48 h has little effect; it affects the volume of large and medium pores. The addition of surfactants during precipitation and washing leads to the increase of large and medium pores volume. Surfactants eliminate relatively efficiently the effect of aging time. Cationic and nonionic surfactants act similarly, but with different intensity, affecting the porous structure of aluminium hydroxide.