Adsorption and adhesiveness of kapok fiber to different oils

Adsorption and adhesiveness of single kapok to various oils, such as diesel, vegetable oil, used motor oil and motor oil were quantitatively evaluated by size and adhesive energy distribution of adsorbed oil droplets on fiber via drop-on-fiber micro-sorption experiments based on Carroll's theory of droplet morphology. Meanwhile, another micro polyester fiber was investigated as comparison. It was found that kapok fibers exihibited low surface energy of 40.64 mN/m with highly hydrophobicity and oil wettability. It had high water contact angle up to 151°, adsorbing four oils with average droplet size varying from emulsified state(0.1-25 μm) to dispersed state (25-100 μm). The average adhesive energies of kapok to four oils were 3.78×10(-11)-9.40×10(-11) J, with the highest for vegetable oil. Compared with kapok, polyester fiber adsorbed a large number of smaller oil droplets with their average size within emulsified state for its large specific surface area contributed by micro-fine of the fiber, but showed bad adhesiveness to retain the adsorbed oils with average droplet adhesive energy among 1.49×10(-11)-2.27×10(-11)J due to its relative higher surface energy of 59.15 mN/m. It is more suitable to be used as filter for secondary fine filtration under low inflow rate.