|
Purpose of this paper is to study the preparation of high-performance hollow fiber composite nanofiltration membrane. In this study, pressure dense, cheap, easy to polysulfone-based hollow fiber membrane spinning, the aqueous phase monomer piperazine, trimesoyl chloride, the organic phase monomer triethylamine as acid acceptor, by interfacial polymerization reaction of the base film thin functional layer formed on the surface to prepare a high pressure trimesoyl piperazine amide / polysulfone membrane, with 0.1% MgSO4 solution as the test solution was measured in the hollow fiber composite membrane desalination under 0.4MPa of 99%, through the volume of 30 L · m ~ -2 / h. This paper conducted research in four areas: First, on the basis of preliminary work on the synthesis trimesoyl chloride (TMC) technology roadmap has been improved, extending the reaction time and the pump suction time, collecting 51mmHg at 198 - 202 ℃ fractions TMC to get high-quality products, test the operability of the repeatability enhancement, product quality and stability. Second, the use of C-shaped nozzle, by adjusting the composition of the spinning solution, the spinning temperature, air bath height, the winding speed of different morphology spun polysulfone-based hollow fiber membranes, and the base film were tested , to obtain a molecular weight cut of 6000 and 20000, respectively, the hollow fiber-based membranes. Third, the use of two different molecular weight cut-based hollow fiber composite membrane, and found that the molecular weight of 20000 by cutting the base film composite membrane prepared performance is much better than by cutting a molecular weight of 6000 prepared a base film composite membrane. In the interfacial polymerization process by adding triethylamine shorten time preloading the composite membrane obtained excellent performance, stable nanofiltration hollow fiber composite membrane. Preparation of composite membranes following conditions: the concentration of piperazine 2% aqueous phase, the organic phase trimesoyl chloride concentration of 0.5%, an acid acceptor concentration of 1% triethylamine, the aqueous phase treatment time of 4min, the organic phase processing time is 30s . Fourth, the use of various means of the resulting hollow fiber composite membrane structure and properties were studied, the results showed that: a functional layer composite membrane thicker, and its rejection rate is higher, the lower the flux; functional layer and the outer surface of the uneven granular form, increasing the contact area with the solution, enhancing the surface charge, thereby improving the rejection rate and flux. V. Preparation of two kinds of polyethylene trimesoyl piperazine amide / polysulfone composite membrane nanofiltration: hollow fiber composite membrane and flat composite membrane, the separation of the two properties were studied. Results show that, although the same polymerization conditions, the base film of a similar nature, flat membrane and hollow fiber membrane performance difference is obvious. Compressive stress and deformation of the two, that the difference between two kinds of composite membrane performance because the flat membrane and hollow fiber membrane stress of different forms.
|