Fabrication Of Extreme Wettability Rice Straw Fiber Felt And Its Performance Research

The oil spill accidents at sea and factory and the discharges of industrial oily sewage occur all the time.It causes serious ecological and environmental problems and also makes threats to human life,health and safety.How to achieve the goal of separation for the mixtures and solve the pollution of oily sewage is currently a center issue of everyone's research.This research direction has important application value and theoretical significance.Comparing with the traditional oil-water separation method,the method achieved the separation of mixtures through the affinity difference for water and oil of extremely wettable material.This method also has high separation efficiency and great application prospects.At present,many methods have been proposed to achieve oil-water separation based on extreme wettability.But most methods have the many problems such as high preparation cost,complicated process and the use of substances that damage the ecological environment in the preparation process.Based on these problems,this method is using rice straw that is a common agricultural waste in life to prepare superhydrophilic straw fibers felt and superhydrophobic in this paper.They are low cost and environmentally friendly products.This straw fibers felt with extreme wettability has functions of separation and adsorption.The main research contents of this article are as follows:(1)The preparation process and wetting mechanism of two kinds of extreme wettability straw fibers felt were studied.The optimal processing parameters in the fabrication process was explored.Then the wettability of surface,micromorphology and composition of the straw fibers felt were analyzed.The causes of its extreme wettability characteristics was also explored.The test showed that rice straw was treated by mixed solution of A with a mass fraction of 10%.After treatment,the surface of straw fibers was refined to form rough and uneven structure to obtain superhydrophilicity property.Subsequently,the reagents with volume ratio of 1:20was uesed as low surface energy modification to obtain straw fibers felt with better super-hydrophobicity properties.(2)The super-hydrophobic and superoleophilic straw fibers felt was carried acid resistance,friction resistance,water pressure resistance and wettability stability test.The results show that the straw fibers felt can withstand the height of 22 cm water column in the water pressure resistance test.That indicates the straw fibers felt can sustain 2.2 Kpa hydrostatic pressure.It was also found that the contact angles of the fibers felt kept above 152 ° with strong acid condition of PH=1.It still maintainedgood super-hydrophobic properties.Next the fibers felt was hold to make it move backward and forward 50 times on 1200 mesh sandpaper with a length of 15 cm.The water droplets on the fibers felt surface still appeared spherical after reciprocating friction.The average contact angle was 153 °.That showed that it had good friction resistance.(3)The super-hydrophilic and underwater superoleophobic straw fibers felt was applied to oil-water separation applications.The separation ability of the straw fibers felt for different types of oil-water mixtures,adsorption capacity of the straw fibers felt for different types of oil and the separation ability under harsh environments were explored.According to the result,the separation efficiency of two kinds of extreme wettability straw fibers felt for oil/water mixtures with different dynamic viscosity coefficients was also higher than 94%.The oil content in the water after separation was less than 80 ppm.It shown that the straw fibers felt had good separation efficiency and separation purity.And it still had high separation efficiency in harsh environments such as high concentration sulfate.Super-hydrophobic and superoleophilic straw fibers felt can also quickly absorb oil on the water.It can absorb about 4-6 times of its own quality for different kinds of oil.Proved that the fibers felt also had high absorption rate.The adsorption capacity of super-hydrophobic and superoleophilic straw fibers felt in turbulent was also investigated.The results show it has good adsorption characteristics,separation efficiency and separation purity.