Relationship between wettabilities and chemical compositions of candle soots

The soot particles formed in the inner flame region and the flame tip of a paraffin candle were collected, and their morphologies and chemical compositions have been studied. The wettabilities of the soot particles were also investigated through dispersing the soot particles in water, trichloromethane or glycerin, and dropping these solvents on the surface of the soot particles. The results show that the inner flame soot particles are superhydrophobic and superoleophilic, because they are relatively large particles and aggregated, and are mostly composed of organics. The flame tip emits ultrafine particles, which mainly consist of elemental carbon and ash, and the flame tip soot particles are loose aggregates. So the flame tip soot particles are hydrophilic and oleophilic.