| Summary: | 碩士 === 國立宜蘭大學 === 化學工程與材料工程學系碩士班 === 104 === The research work use polyacrylonitrile (polyacrylonitrile, PAN) as the film support material, chitosan as a dense skin, inorganic tetraethyl orthosilicate (tetraethoxysilane, TEOS) in different proportions and inorganic silica (silica, silicon dioxide, SiO2) nanoparticles with different diameters in different proportions as additives for chitosan, nanofiltration (NF) membrane is prepared and analyzed. The emphasis of research work is put on the control of both the structure and the charged property of membrane via the addition of inorganic particles in different proportions and in different sizes, to establish the customization technique of nanofiltration membrane. Some conclusions could be made based on the analysis of experimental results: (1) from the analysis of laser zeta sizer and of FE-SEM, the prepared silica particles are concentrated in their diameter distribution, of completeness in their spherical configuration, of good reproducibility in preparation, and highly controllable in their size by adequate addition of ammonia with known concentration; (2) from the analysis of FE-SEM and of EDS Si element content, when the inorganic particles are getting smaller, the practical content of inorganic material in chitosan tight layer will get lower, and meanwhile, the particles coagulate more seriously, and in addition, when the added amount of inorganic material increases, the particles coagulate more seriously also; (3) under the effects of total crosslinking reaction sites and of steric retardation, the flowrate of filtrate of PAN membrane and PCS membrane gets smaller gradually, and gets larger gradually onward, when the inorganic particles get bigger, and an extremal diameter for particles exists at which the flowrate of filtrate is the smallest, and in addition, when the added amount of inorganic material increases, the practical content of inorganic material in chitosan tight layer gets higher, and correspondingly, the flowrate of filtrate gets smaller; (4) the experimental results of filtration for salt MgSO4 solution reveal that for PAN membrane and PCS membrane, when the inorganic particles get bigger, the particles coagulate more mildly, and the salt retention is more stable if the added amount of inorganic material changes, and in addition, the salt retention of PCS membrane could be higher than that of commercial membrane NF270 when the added amount of inorganic material is small enough.
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