An accurately weighed amount of C. gigantea fiber (50 mg) was dipped into 50 mL of oils for different time at room temperature. Afterwards, the swollen fiber was separated using a stainless steel mesh, drained for 10 min for soybean oil and engine oil, and for
10 s for kerosene, and quickly weighed. The oil absorption capacity per gram of fiber at any time can then be calculated according to the weight ratio of the absorbed oil to the dry fiber. Each sample was independently measured for three times and an average value was used for comparison.