The Modification Of Metal Surface And Its Application In Separation

In recent years, more and more scientists are focused on researching and preparation of novel multifunctional superhydrophobic materials as it has showed unique superiority in many application fields. In fact, the requirements for surface wettability is diverse in practical application,sometimes, someone required the liquid could rapidly infiltrate the surface, whereas others demand the surface to resist liquid strongly. So far, most explorations of surface wettability were based on pure liquid,such as water or some organic solvent. Limited study had been done on the wettability of a miscible liquid mixture, which is a very practical problemworth to be deeply inquired in many industrial.This paper mainly includes the following aspects:(1) A special rough structure on the stainless steel surface was prepared by electroplating and the composition of Cu SO4 electroplating solution, the best reaction temperature, time, current were determined. And then made these meshes modified with HS(CH2)11CH3/HS(CH2)2OH mixed solution.Experiments show that the surface contact angle decreased from 152°to25 ° with the increase of XOH which indicated that we can obtained surface with different wettability just by controlled the composition of modifier(XOH is the mole fraction of HS(CH2)2OH in the modified solution). In addition, the p H and salt content of the liquid drop had no effect on the contact angle of the surface. The osmotic concentration ofethanol/acetone solution on these surface(XOH=0, 0.2, 0.4, 0.6, 0.8, 1.0)was studied systematically and the ethanol was 39%, 35%, 27%, 23%,16% and 0, the acetone was 63%, 55%, 50%, 28%, 19% and 0,respectively. Using homemade device, we have achieved the preliminary separation of ethanol solution with different concentration,but the cycle of these surfaces was poor and it would be destroyed after 3 times reused.(2) Copper meshes with different wettability were obtained by immersing these surfaces into mixed solution with various XOH. And then studied the wettability of ethanol on the surface and the contact angle decreased with the increase of the concentration of ethanol, the osmotic concentration of ethanol solution on these surface(XOH=0~1.0) was 31%,33%, 36%, 41%, 43%, 47%, 44%, 44%, 38%, 33% and 0 respectively.Otherwise, we preliminary explore the relationship between the permeability of ethanol and the concentration, hydraulic. We also have determined the best whole concentration of modifier is 5~10 mmol/L, the optimum reaction time is 12 h to get a surface with high osmotic concentration. The recycling of copper meshes were discussed in the separation experiment and it show a good recycling property which could be reuses for at least 30 times. These studies may have great value in the separation of mixed solution, fluid monitoring and fluid diversion.