| Oily waste water brings a lot of inconvenience to human beings,so the removal of waste oil from water with a cheap and efficient way is a crucial problem to be solved.Natural fibers are becoming more and more popular as oil absorption materials due to advantages such as excellent oil absorption capacity,cheap price,rich resources,renewability,biodegradability,etc.This paper focused on three kinds of natural fibers:kapok fiber,cattail fiber and cotton fiber.The oil absorption property of bulk fiber assemblies was studied.Then different blending ratio battings were made through proper techniques.The structural parameters and oil absorbency of these battings were tested and analyzed.Then the effect factor was discussed and different methods of contact angle were compared and analyzed.The study helps to make clear the oil-absorption property of three fiber assemblies,and to provide the basis for their usage in oil absorption field.The main work and conclusions are as follows:(1)Oil-absorption performance of bulk fiber assemblyThe fundamental characteristics of kapok,cattail and cotton fiber assemblies were investigated with the evaluation indexes of oil-absorption and oil-retention.It was founded that,the moisture regains of these three kinds of fibers were more than 10%,and their contact angles with oil were less than 70°.Oil absorption rates of kapok,cattail and cotton fiber assemblies were 25.79 g/g,11.91 g/g,14.98 g/g,and oil retaining rates of them were 25.79g/g?11.91 g/g?14.98 g/g respectively.(2)Fiber batting preparationBy combining kapok,cattail and cotton with ES fibers,we made 18 kinds of battings with different blending ration.The batting preparation technique determined by experiment is as follows,ES fibers percentage of 10 to 20%,oven temperature of 140°,pressure of 292Pa and heating time of 30min.The structural form and bonding situation were observed by SEM.Also,the thickness,volume and density of these 18 kinds of battings were tested and calculated.(3)Oil-absorption property of battingsThe oil-absorption rates and oil-retention rates of 18 kinds of battings were tested and evaluated.It was revealed that,the oil-absorption rates of kapok/ES,cattail/ES and cotton/ES battings exceed 23 times,11 times and 16 times respectively of their own weight,and the oil-retention rates of these three kinds of battings were all more than 85%.Comparatively speaking,the kapok/ES kapok fiber batting has the best oil-absorption property.For the battings made by two kind of natural fibers with ES fibers,the oil-absorption rates were worse than the kapok battings but better than the cattail battings,and the oil-absorption rates were more than 85%.The oil absorption rates of all the battings were higher in the pure oil than in the oil/water liquid.(4)Influence factors of the fibers' adsorptionFiber morphology,pore structure of the fiber assemblies and oil character were the factors which influence absorption property.Oleophylic characterastic of fibers,the hollow structure of kapok fiber,the nature twist of cotton fiber,the open structure of cattail fiber,and the pore in the assembly provide the space for oil storage.The oil status and oil type also influence the capacity of oil absorption.(5)Comparison and analysis of test methods of fiber contact angleThe contact angles of kapok,cattail,cotton,bamboo,viscose fibers with water and oil were tested by OCA15EC and DCAT11 using static contact angle testing methods such as plate,sessile drop,and dynamic contact angle testing methods such as Wilhelmy and Washburn.Then the results of these four methods were compared and analyzed.It was indicated that plate method was suitable for flat fabrics and film,it can be used to test the fibers pasted to the plate.Sessile drop method was used to test the fibers or yarnms with higher liner and stiffness.Wilhelmy method was appropriate for materials with high stiffness and regular cross section.Washburn method was used to test the powder materials with contact angle between the material and liquids less than 90°. |
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