Preparation of PVDF/SiO2 composite membrane for salty oil emulsion separation: Physicochemical properties changes and its impact on fouling propensity

29th Symposium of Malaysian Chemical Engineers 2016

Ngang, H.P.^1 ; Ahmad, A.L.^1 ; Low, S.C.^1 ; Ooi, B.S.^1

School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, Nibong Tebal, Pulau Pinang

14300, Malaysia^1

关键词: Cross-section morphology;    Field emission scanning electron microscopes;    Hydrophilic characteristics;    Hydrophilicity enhancements;    Hydrophobic interactions;    Particles concentration;    Physicochemical property;    Polyvinylidene fluorides;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/206/1/012083/pdf
DOI  :  10.1088/1757-899X/206/1/012083

来源: IOP

【 摘 要 】

In this study, polyvinylidene fluoride (PVDF)/silica (SiO2) composite membranes were prepared by diffusion induced phase separation through direct blending method. The roles of SiO2particles concentration on membrane physicochemical properties were evaluated through oil emulsion separation under high ionic strength environment whereby hydrophobic interaction is prevalent. Membranes were characterized using field emission scanning electron microscope (FESEM), atomic force microscopy (AFM), contact angle measurement, membrane porosity and pore size distribution. It was expected that by adding the monodispersed SiO2, it will render the membrane with hydrophilic characteristic. However, it is concomitantly changing the physical properties of the membrane. Addition of SiO2caused the changes to the physicochemical properties of the composite membrane and its effects on the fouling propensity were evaluated. It was found that the mean pore size of the membranes increased with the increase of SiO2concentration. The addition of hydrophilic SiO2had accelerated the precipitation of the membrane dope solution resulting in changes of membrane cross section morphology. FESEM images showed the membrane cross-section morphology of PVDF/SiO2composite membrane had gradually changed from finger-like to macrovoid-like structure with the increased of SiO2concentration. The hydrophilicity of the PVDF/SiO2composite membrane was enhanced which is a desired property for water purification. However, the changes in physical properties (pore size, porosity, and surface roughness) had played more dominant role in the oil emulsion fouling behaviour rather than hydrophilicity enhancement. Due to the salting out effect under high ionic strength environment, hydrophobic interaction played an important role in the oil adsorption. The increment in membrane pore size, porosity, and surface roughness after incorporation of SiO2particles had encountered more serious relative flux reduction and lower flux recovery ratio.