Using saponified olive oil to make cost effective calcium carbonate particles superhydrophobic
Résumé
The main goal of this paper is to show that superhydrophobic particles of calcium carbonate can be synthesized at low cost from harmless biocompatible natural products like baking soda (NaHCO3) and olive oil. Calcium carbonate particles were prepared by precipitating solutions containing CO32− and Ca2+ ions at two different temperatures 30 °C and 80 °C. These particles were transformed into hydrophobic ones using soap made from olive oil from the region of Kabylie (Algeria). The olive oil was first saponified. Adjusted amounts of this soap were added to the sodium carbonate solution before the precipitation reaction. Several techniques were used to analyze the products of the reaction. Typical polymorphs of CaCO3 (calcite, aragonite and vaterite) were identified by quantitative analysis of X-ray powder diffraction patterns, giving their crystallite size and atomic fractions. Scanning electron microscopy was used to probe the morphology of the CaCO3 particles. FT-IR measurements indicated the presence of aliphatic chains in the hydrophobic particles, thereby proving that the calcium carbonate particles were functionalized by soap. The particles which formed were found to be superhydrophobic with a contact angle of up to 175°. Evidence of the efficiency of these particles in oil spill recovery is given.