Ultrafiltrasi digunakan secara meluas dalam industri untuk menapis zarah yang mecemarkan. Banyak kajian telah disiasat untuk memahami tentang penurunan fluks kerana protein fouling. Dalam kajian ini, fluoride polyvinylidene (PVDF) membran telah disediakan melalui penyongsangan fasa. Kesan membran parameter sintesis iaitu kepekatan polimer(18wt%- 22wt%), pembekutan suhu air (10°C - 24°C ) dan hydroxylation kimia membran telah dikaji. Dalam usaha until menguji parameter sintesis membrane, kesan interaktif parameter ini dinilai dengan menggunakan permisahan BSA penampan solusi. Ciri-ciri fizikal membran PVDF telah disifatkan berdasarkan taburan saiz liang, keporosan membran, mikroskop electron imbasan pancaran medan (FESEM), spektroskopi inframerah ubah fourier (FTIR) dan sudut sentuh. Ia telah mendapati bahawa semua parameter ini mempengaruhi sifat sifat termodinamik and kinetic solusi polimer yang akan membawa kepada kesan yang besar ke atas morfologi dan prestasi membran. Kepekatan polimer 22wt%, ketebalan tuangan 200µm merupakan parameter sintesis membran optimum yang akan kita gunakan sepanjang kajian. Nilai eksperimen fluks penyerapan dan penolakan adalah 75.22+1.06 L/m2.h dan 75.06+ 2.38% masing masing. Ini adalah kerana lebih tinggi kepekatan polimer membran biasanya memberi struktur padat and kompak, saiz liang yang lebih kecil and ticker membran. Inilah sebabnya mengapa penolakan dan permulihan fluks yang lebih baik dan penyerapan fluks yang lebih rendah. Untuk kesan CBT terhadap prestasi membran, membran PVDF yang tenggelam dalam CBT 24°C mempunyai prestasi membran yang lebih baik berbanding dengan membran lain dengan masing masing fluks penyerapan and penolakan, iaitu 52.59+2.70 L/m2.h dan 83.64+0.82%. Struktur permukaan membran PVDF telah dianalysis menggunakan SEM and ia menunjukkan bahawa saiz liang menurun manakala permukaan keliangan meningkat pada suhu yang lebih tinggi. Dari segi struktur membran keratin, pada CBT yang lebih tinggi, membran mempunyai struktur jari- seperti yang nipis dan lapisan span yang tebal. PVDF membran kemas dan hydroxylated PVDF membran (PVDF-OH) telah disiasat dan dibandingkan. PVDF-OH membran menunjukkan kebolehtelapan tinggi protein berbanding dengan membrane kemas, iaitu 51.05 6.13 L/m2.h. Ini telah menunjukkan bahawa PVDF-OH membran mempamerkan sifat rintangan fouling. Ia adalah disebabkan oleh kesan hydroxylation yang mengurangkan interaksi hidrofobik antara membran dan protein. Nisbah permulihan fluks (FRR) telah dikira, iaitu 44.24% bagi membran kemas and 66.38% bagi hydroxylated PVDF membran. Fluks yang lengkap dipulih bagi membran hydroxylated menunjukkan bahawa membran dengan kumpulan hidroksi mempunyai ciri-ciri anti-fouling yang lebih baik.
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Ultrafiltration is widely used in industry to filter out particulate matter that contaminates or slows down the performance of the membrane. Numerous studies have been investigated to further the understanding of flux decline due to protein fouling. In this study, polyvinylidene fluoride (PVDF) membranes were prepared via phase inversion. The effect of membrane synthesis parameter namely, polymer concentration (18wt%-22wt %), coagulation bath temperature (10°C to 24°C) and chemical hydroxylation of membranes were investigated. In order to test the membrane synthesis parameter, the interactive effects of these parameters were evaluated by using BSA buffer solution separations. The physical properties of PVDF membranes were characterized based on pore size distribution, membrane porosity field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy and contact angle. It was found that these parameters were simultaneously affecting the thermodynamic and kinetic properties of the polymer solution which leads to the significant effect on membrane morphology and performance. The optimum membrane synthesis parameters were obtained by having a polymer concentration of 22wt%, casting thickness of 200µm. The experimental value of permeation flux and rejection were 75.22+1.06 L/m2.h and 75.06 2.38% respectively. This is because higher polymer concentration membrane normally exhibits denser and compact structure, smaller pore size and ticker membrane. This is why better rejection and flux recovery but lower permeation flux. For the effect of CBT on membrane performance, the PVDF membrane which immersed in CBT of 24°C having better membrane performance compared to others with the permeation flux and rejection of 52.59+2.70 L/m2.h and 83.64+0.82% respectively. The surface structure of the PVDF membranes were analysed using SEM which show that the pore size decreased while the surface porosity increased at higher temperature. In term of cross-section membrane structure, at higher CBT, the membrane having thinner finger-like structure and thicker sponge layer. The neat PVDF membrane and hydroxylated PVDF membrane (PVDF-OH) were investigated and compared. PVDF-OH membrane shows higher proteins permeability as compared to neat membrane which is 51.05 6.13 L/m2.h. This indicates that PVDF-OH membrane exhibits protein fouling resistance properties. It is attributable to the effect of hydroxylation which reduced the hydrophobic interaction between the membrane and protein. The flux recovery ratios (FRR) were observed to be 44.24% and 66.38% for neat and hydroxylated PVDF membrane accordingly. The complete flux recovered was observed for hydroxylated membrane indicated that the membrane with hydroxyl group perform better anti-fouling properties.
Pvdf membrane functionalization and its evaluation on proteins fouling / Kow Shu Wen