Temperature Effect on Oil Sorption and Wettability of Kapok Fiber

ABSTRACT

Kapok fiber as a natural sorbent with excellent hydrophobic-oleophilic characteristic was studied. The effect of temperature on oil sorption behavior and wettability of kapok fiber powder was quantitatively evaluated by capillary rise method. Results showed that at the packing density of 0.1 g/cm³, the oil sorption capacity of kapok fiber powder presented only about 5% difference when the temperature ranged from 20°C to 90°C, with the values to engine oil, mineral oil, and PAO4 ranging from 10.96 to10.42 g/g, 10.73 to 10.18 g/g, and 10.25 to 9.89 g/g, respectively. However, the sorption coefficient which related to the sorption rate increased almost exponentially with the increasing of temperature. Then, the oil wettability of kapok fiber powder was further investigated from the perspective of contact angle. Nearly logarithmic increment in contact angle between the fiber powder and test oil was observed when higher temperature condition was applied, indicating that the enhancement of temperature apparently weaken the wettability of oil to solid powder. The adhesion work between fiber powder and oil was evaluated based on Young–Dupré equation, which suggested that higher temperature lead to lower adhesion work. Outcomes from this research are believed to provide importance reference for the usage of kapok fiber as sorbent when different temperatures are applied.

摘要

研究了木棉纤维作为一种具有优良疏水亲油特性的天然吸附剂. 采用毛细管上升法定量研究了温度对木棉纤维粉体吸油行为和润湿性的影响. 结果表明, 当填充密度为0.1g/cm3时, 木棉纤维粉在20～90℃范围内的吸油量仅相差5%左右, 对机油、矿物油和PAO4的吸附量分别为10.96～10.42g/g、10.73～10.18g/g和10.25～9.89g/g. 随着温度的升高, 与吸附速率相关的吸附系数几乎呈指数增长. 然后, 从接触角的角度进一步研究了木棉纤维粉的油润湿性. 在较高的温度条件下, 纤维粉与试验油的接触角几乎呈对数增长, 表明温度的提高明显削弱了油对固体粉末的润湿性. 基于杨-杜普方程对纤维粉与油之间的粘附功进行了计算, 结果表明, 温度越高, 粘附功越低. 研究结果可为不同温度下使用木棉纤维作吸附剂提供重要参考.

KEYWORDS:

• Kapok fiber
• oil sorption
• temperature
• contact angle
• adhesion work

Key Words 关键词:

• Kapok fiber
• 木棉纤维, oil sorption
• 吸油作用, temperature
• 温度, contact angle
• 接触角, adhesion work附着功

Acknowledgments

The research is financially supported by “National Natural Science Foundation” (numbered by 51903034), and “the Fundamental Research Funds for the Central Universities” (numbered by 2232019D3-12).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [51903034].