Polymer processing
Shahab Hoseinpour; Yoones Jafarzadeh; Reza Yegani; Sepideh Masoumi
Abstract
The aim of the present work is to enhance the antifouling properties of polypropylene (PP) membrane based on hydrophilicity improvement. Different contents of neat and modified nanodiamond (0.25, 0.50, 0.75 and 1.00 wt.%) were embedded into PP membranes. Nanodiamond nanoparticles were carboxylated by ...
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The aim of the present work is to enhance the antifouling properties of polypropylene (PP) membrane based on hydrophilicity improvement. Different contents of neat and modified nanodiamond (0.25, 0.50, 0.75 and 1.00 wt.%) were embedded into PP membranes. Nanodiamond nanoparticles were carboxylated by heat treatment method and the presence of carboxyl functional groups on the surface of nanoparticles was confirmed by FTIR analysis. Membranes were then characterized by FESEM, contact angle and tensile strength tests. At the same content of nanoparticles, hydrophilicity, pure water flux and tensile strength of PP/ND-COOH membranes were more than those of PP/ND membranes. Membranes embedded with 0.75 wt. % of neat and modified nanoparticles were used in a submerged membrane bioreactor (SMBR) system along with neat PP membrane. The results showed that critical flux values for neat PP, PP/ND and PP/ND-COOH membranes were 7, 18 and 22 L/(m2.h), respectively. Analysis of fouling mechanisms revealed that antifouling properties of 0.75 wt. % PP/ND-COOH membrane were higher than those of other two ones so that irreversible fouling ratio decreased from 88.9% for neat PP to 47.8% for PP/ND-COOH membrane.
Ali Behboudi; Yoones Jafarzadeh; Reza Yegani; Ali Akbari
Abstract
Grinded glass fiber (GGF) embedded high density polyethylene (HDPE) membranes were prepared via thermally induced phase separation method. FESEM images showed that all the membranes had leafy structure, indicating a solid-liquid mechanism during phase separation. The results of EDX and TGA analyses confirmed ...
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Grinded glass fiber (GGF) embedded high density polyethylene (HDPE) membranes were prepared via thermally induced phase separation method. FESEM images showed that all the membranes had leafy structure, indicating a solid-liquid mechanism during phase separation. The results of EDX and TGA analyses confirmed that the fibers were dispersed in the HDPE matrix uniformly. Normalized water flux of the membranes increased from 1 for the neat HDPE membrane to more than 4 for 10 wt% GGF/HDPE membrane. Moreover, the contact angle decreased from 129° to 94° as the GGF content increased in the membranes, showing an improvement in the surface hydrophilicity of the membranes. The AFM results revealed that the surface roughness of the membranes was increased with increasing the GGF content. The results of abrasion test revealed that the GGF/HDPE membranes had a more abrasion resistance than the neat HDPE membrane. Finally, the fouling behavior of the membranes was investigated by the filtration of BSA protein solution and the results showed that with increasing the glass fiber content, total fouling ratio decreased from 90% for the neat HDPE membrane to 62% for 10 wt% GGF/HDPE membrane, indicating that the antifouling properties of the membranes were improved due to the presence of glass fiber.
Characterization
Setareh Heidari; Yoones Jafarzadeh; Mahdi Seyfollahi Samarin; Reza Yegani
Abstract
In this study, neat HDPE and HDPE/PE-g-MA/EVA blend membranes were fabricated via thermally induced phase separation (TIPS) method and their fouling behaviors were examined using filtration of BSA protein. Membranes were characterized using FESEM, AFM, ATR-FTIR analyses and porosity measurement. Fouling ...
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In this study, neat HDPE and HDPE/PE-g-MA/EVA blend membranes were fabricated via thermally induced phase separation (TIPS) method and their fouling behaviors were examined using filtration of BSA protein. Membranes were characterized using FESEM, AFM, ATR-FTIR analyses and porosity measurement. Fouling behavior of membranes was analyzed using the resistance-in-series (RIS), classic and combined pore blocking models. The results of RIS model revealed that the magnitude of inherent, reversible and irreversible resistances decreased from 0.611 ×1013m-1 and ,1.578 ×1013m-1 and 0.525 ×1013m-1 for the neat membrane to 0.237 ×1013m-1, 0.789 ×1013m-1 and 0.154×1013m-1 for the blend membrane, respectively. None of the classical Hermia’s models were able to accurately predict fouling during the entire filtration run. The results obtained from the combined pore blocking model indicated that the combined cake formation-intermediate blocking model provided good prediction of fouling mechanism for both the membranes. However, comparison between fitted parameters showed that much greater fouling occurred for pure HDPE membrane. The key reasons for such different fouling behaviors were mainly attributed to the difference in hydrophobicity as well as the distribution of pore size on the surface of the pure and blend membranes.
