Preparation And Performance Of Modified Ramie Fiber For Oil Absorbing By Sol-gel Method

Oil pollution is one of the main types of marine pollution,and oil spill has become the main way for getting into the ocean.When the oil spill occurs,a large amount of oil is released which could not only caused the marine ecological environment and water ecological environment pollution,but dangerous chemicals released are toxic to aquatic organisms and humans.It may require decades of time to remove.Therefore,how to effectively control the oil pollution and repair the ecological environment becomes a hot topic of concern.The successful synthesis of hydrophobic Boehmeria tricuspis fiber(BTF)with a porous network by a sol-gel polymerization process using ethyl silicate reactants with the addition of octadecyltrichlorosilane(OTS)surfactants.The hydrophobic properties of crude and modified BTF are evaluated from different aspects.Results showed that the variation size of the BTF had a effect on its oil absorption and the best was particle size of 20-40 mesh which was taked as the follow-up modified object based on the relevant experiment results.The rapid absorption and saturated water absorption of modified BTF were decreased by 94.25% and 94.26%,which showed a superhydrophobic modification.The maximum oil adsorption capacity of modified Boehmeria tricuspis fiber was 15 time for crude oil.For diesel oil,lubricating oil,soybean oil and peanut oil,the retention rate achieved stability within 30 minutes and the rate is respectively 84.08%,67.97%,70.15% and 67.05%,with an increase of about 1.01 times,1.21 times,1.19 times and 1.23 times.The structure and property of the obtained BTF were characterized by FTIR,SEM,XRD,TG and contact angle measurements.The hydrophilic groups of modified BTF was decreased with the emergence of the hydrophobic group Si-O-Si.The surface of modified BTF appeareed granular material and the coarse structure was constructed.The crystalline of modified BTF decreased with non crystalline region increase.The moisture content of modified BTF became smaller,the main pyrolysis temperature became larger,the pyrolysis rate became smaller,and the small molecular side chain content decreased.Improving the SiO2 nanoparticles were covered on the surface of modified BTF,so that it had a better performance of hydrophobic and lipophilic properties.The contact angle of crude BTF on water was almost 0° and modified BTF with an angle of 113°±1°,which showed strong hydrophobic.After the modification the contact angle on lubricating oil,crude oil and soybean oil was 33°±1°,20°±1°,29°±1°,respectively.According to the dynamic contact angle model,the k0 of water,lubricating oil,crude oil and soybean oil was-0.08,0.24,0.14 and 0.23,respectively.The critical surface tension value of modified fiber was calculated by the least square method,and the range value was 19.30-86.86 mN·m-1.