基于光学测量的异形纤维润湿性差异研究

气液聚结过滤在过程工业领域具有广泛应用,纤维材料润湿性是影响聚结元件过滤性能的关键因素。基于光学测量法,本工作开展了单根三角形、三叶形和十字形纤维表面的液体润湿性差异研究,分析了液体接触角及体积的变化过程,考察了液体类型、纤维倾斜角度及异形度对润湿性的影响。结果表明,液体表面张力越小,接触角越小,润湿性越强,但液体的挥发性易导致实际接触角大于理论接触角。三甘醇、癸二酸二辛酯和硅油的接触角基本不随时间发生变化,水和乙醇的接触角随时间逐渐减小且由于乙醇挥发速率较高,导致减小速率更大。液体接触角随异形纤维的倾斜角度呈“V”形分布,即存在极小值点(倾斜角度为30°),使纤维润湿性达到最佳。当纤维异形度增大时,不同液体间的接触角差异缩小、整体润湿性提高,表明在制备预过滤层或排液层材料时,宜选择异形度较高的纤维。

Study on wettability difference of profiled fiber based on optical measurement

Gas-liquid coalescence filtration is widely used in process industry. The wettability of fiber material is the key factor affecting the filtration performance of coalescing element. Based on the optical measurement method, the wettability difference of liquid on the surface of single triangular, trilobal and cruciform fiber was studied. The change process of liquid contact angle and volume was analyzed, and the influence of liquid type, fiber inclination angle and profiled degree on wettability was investigated. The results showed that with the decrease of liquid surface tension, the contact angle reduced and therefore the wettability enhanced. However, the volatility of liquid was easy to cause the actual contact angle to be greater than the theoretical one. The contact angle of triethylene glycol, dioctyl sebacate and silicone oil did not change with time. The contact angle of water and ethanol gradually decreased with time, and the decreasing rate of ethanol was greater due to the higher evaporation rate. The contact angle of liquid presented a "V" shape distribution with the inclination angle of the profiled fiber, that was, there was a minimum point (inclination angle of 30°) to make the fiber wettability reach the best. When the profiled degree of the fiber increased, the contact angle difference between different liquid decreased and the overall wettability improved, which indicated that the fiber with higher profiled degree should be selected as the material of prefilter layer or drainage layer.