scholarly journals Characterization on Performance, Morphologies and Molecular Properties of Dual-Surfactants Based Polyvinylidene Fluoride Ultrafiltration Membranes

2019 ◽  
Vol 64 (3) ◽  
pp. 320-327
Author(s):  
Abdul Rahman Hassan ◽  
Che Wan Insyirah Che Wan Takwa ◽  
Nurul Hannan Mohd Safari ◽  
Sabariah Rozali ◽  
Nor Azirah Sulaiman

This paper addressed the pioneering work on the effects of dual surfactants component on the performance, morphologies and molecular properties of polyvinylidene fluoride/polyether glycol (PVDF/PEG 200) ultrafiltration (UF) membranes. The PVDF surfactant membranes were prepared via dry/wet via phase inversion technique with the addition of sodium dodecyl sulfate (SDS)/Tween 80 and Triton X-100/Tween 80 into polymer solution. Experimental data revealed that the dual surfactants improved the membrane performance up to 120.84 L/m2 × h and 82 % of permeate flux and rejection of bovine serum albumin, respectively. In addition, 2 wt% of dual surfactants alsofound to induce the growth of fine finger-like and macro-voids cavities inside the membranes while the FTIR spectra proved that the existence of dual surfactants in PVDF membranes produced better molecular alignment which contributed significantly towards better flux and good rejection. In conclusion, the used of dual surfactants in the PVDF ultrafiltration membranes improved the performance-properties of the membranes and extending the possibly versatile for the membrane to be used for more applications.


2018 ◽  
Vol 63 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Nurul Hannan Mohd Safari ◽  
Abdul Rahman Hassan ◽  
Che Wan Insyirah Che Wan Takwa ◽  
Sabariah Rozali

In membrane making, surfactant material is one of the effective strategies to produce membrane / thin film with optimal and specific properties. This paper addressed the effect of Sodium dodecyl sulphate (SDS), Triton X-100 and Tween 80 as additives for the making of Polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes. The fabricated membranes were analysed in the aspect of performance, morphological structures, thermal properties and molecular orientation. Analysis results showed that the surfactant additives enhanced the membrane performance and properties. Surprisingly, the addition of 2 wt% surfactant increased the permeate flux of bovine serum albumin (BSA) up to 78.14 L/m2h compared to membrane without surfactant with flux at only 2.74 L/m2h. In addition, the role of surfactants on membrane pores and pore properties of PVDF UF membranes were examined. The cross-sectional morphological structures showed that these surfactants led towards the formation of macro-voids and finger-like structures as well as a spongy layer. The surfactants additives also improved the membrane pores and pore properties which reflect to the protein rejection up to 85 % and 78 % of BSA and egg albumin (EA), respectively. Moreover, analysis on the thermal features found that SDS, Triton X-100 and Tween 80 promoted better thermal stability and significantly fine molecular alignment which provided the versatility for the membrane to be used for any applications.



2013 ◽  
Vol 67 (10) ◽  
pp. 2154-2159 ◽  
Author(s):  
Baowei Zhao ◽  
Ruirui Li ◽  
Jinkui Zhong ◽  
Li Zhang

The performance of copper ion removal using sodium dodecyl sulfate (SDS) and its mixtures with Brij 35, Tween 80 (TW80) and Triton X-100 (TX100) by micellar-enhanced ultrafiltration (MEUF) was investigated. The effects of the molar ratio of nonionic surfactant to SDS on the critical micelle concentration (CMC) of SDS/Brij 35, SDS/TW80 and SDS/TX100, the removal efficiency of Cu2+, the residual concentration of SDS in the permeate solution and the permeate flux were tested. The results showed that the CMCs of the mixed surfactants were sharply less than that of pure SDS. The removal efficiencies of Cu2+ were up to the maximum values 98.3 and 95.8% when the molar ratios of Brij 35 and TW80 to SDS were 0.3, and it was 93.5% given 0.7 molar ratio of TX100 to SDS. The concentration of SDS in the permeate decreased dramatically with the addition of nonionic surfactant, and the permeate flux decreased slightly as the molar ratio increased. Compared with the performance by single SDS, the mixed SDS/Brij 35, SDS/TW80 and SDS/TX100 at an optimum composition could result in not only higher rejection of Cu2+ but also much less dosage of surfactant and concentration of SDS in the permeate.



Author(s):  
Diego Ramirez ◽  
Liz J. Shaw ◽  
Chris D. Collins

Abstract Different physicochemical and biological treatments have been used to treat oil sludges, and oil recovery techniques are preferred such as oil sludge washing (OSW) with surfactants and co-solvents. Toluene is commonly used as co-solvent, but it is non-benign to the environment. This study tested alternative co-solvents (n-pentane, n-hexane, cyclohexane, and isooctane) at 1:1 and 2:1 C/OS (co-solvent to oil sludge ratio). Also, this study evaluated the effect on the oil recovery rate (ORR) of three main parameters in the washing: type, concentration, and application ratio (S/OS) of surfactants to oil sludges. To date, no study has assessed these parameters in the washing of oil sludges from different sources. Four types of oil sludges and five surfactants (Triton X-100 and X-114, Tween 80, sodium dodecyl sulphate (SDS), and rhamnolipid) were used. The results showed that cyclohexane had high ORR and could be used instead of toluene because it is more benign to the environment. The S/OS ratio had a high effect on the ORR and depended on the type of oil sludge. Rhamnolipid, Triton X-100, and Triton X-114 had the highest oil recovery rates (40 – 70%). In addition, it was found that the surfactant concentration had no effect on the ORR. Consequently, the addition of surfactant was not significantly different compared to the washing with no surfactants, except for one sludge. The use of the surfactant in the washing solution can help in the selective extraction of specific oil hydrocarbon fractions in the recovered oil to assess its potential reuse as fuel. Further recommendations were given to improve the OSW process.



2015 ◽  
Vol 78 (1) ◽  
Author(s):  
A. Moslehyani ◽  
M. Mobaraki ◽  
A. F. Ismail ◽  
M. H. D. Othman ◽  
A. Mayahi ◽  
...  

The objective of this study is to investigate the potential of ultrafiltration polyvinylidene fluoride (PVDF)-titanium dioxide (TiO2) membrane for oil-in-water separator. PVDF polymeric matrix membrane is excellent in term of chemical and thermal stabilities, which make it very promising to be used as a membrane matrix for water separation. However, poor hydrophilic property of the PVDF has led to the severe fouling during operation. Thus, current work was performed to investigate the effect of incorporation of two additives i.e. polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) in PVDF-TiO2 membrane, which fabricated using dry/wet phase inversion technique. Membranes characterizations were performed using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), contact angle and UV-vis spectrophotometer. Accordingly, modified PVDF membrane possessed good hydrophilicity property when the additives were added into PVDF-TiO2 membrane matrix. In term of filtration performance, the experimental results showed that oil rejection using PVDF-TiO2/PVP membrane were ~99.7%, which met the requirement for discharge. On the other hand, PVDF-TiO2/PEG membrane was shown more enhancement in terms of permeate flux by given over 64 (L/m2h) at pressure of 2 bar gauge.



2015 ◽  
Vol 17 (45) ◽  
pp. 30450-30460 ◽  
Author(s):  
Baljinder Singh ◽  
Satvinder Singh ◽  
Janpreet Singh ◽  
G. S. S. Saini ◽  
D. S. Mehta ◽  
...  

Zinc oxide (ZnO) nanostructures with different morphologies are prepared in the presence of surface active molecules such as sodium dodecyl sulphate (SDS), Tween 80 and Triton X-100 by a chemical method.



2013 ◽  
Vol 681 ◽  
pp. 309-313
Author(s):  
Dong Hua Zhang ◽  
Li Jing Pan ◽  
Da Zhi Sun

BaBi2Nb2O9/PVDF (polyvinylidene fluoride) composite ultrafiltration (UF)membranes were prepared by alloying BaBi2Nb2O9 (BBN) particles uniformly in the PVDF solution (15% polymer weight) and used a phase-inversion method. This paper studied the effect of the concentration of BBN from 0% to 5% in 0.2Mpa on pure water flux and rejection rate to Bovine serum albumin (BSA). The cross-sectional structures of composite membranes were observed by scanning electron microscopy (SEM). Moreover, XRD results revealed the crystal structure of PVDF. The experimental results showed that the BBN/PVDF composite ultrafiltration membranes were superior in separation performances than the pure PVDF membranes due to the addition of BBN.



2013 ◽  
Vol 634-638 ◽  
pp. 2072-2076
Author(s):  
Lin Lin Kong ◽  
Da Lun Zhang ◽  
Zi Qiang Shao ◽  
Bai Xin Han ◽  
Ya Liang Chen

Cellulose acetate (CA), a hydrophilic membrane material, was selected to prepare ultrafiltration membrane for the aim of achieving high-performance membranes with respect to flux and rejection characteristics. In order to prepare membranes with improved properties, blending of cellulose acetates with different degrees of substititution(DS) has been attempted. In this study, polymeric blend ultrafiltration membranes based on cellulose acetate with different DS were prepared by phase inversion technique. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle are used to understand the influence of DS on the properties of modified membranes. The blend membranes prepared were subjected to the separation of egg albumin (EA). The separation and permeate flux efficiencies of the blend membranes were discussed.



2021 ◽  
Vol 55 (9-10) ◽  
pp. 989-1000
Author(s):  
SAURABH C. SINGH ◽  
◽  
RUPESH A. KHARE ◽  
Z. V. P. MURTHY ◽  
◽  
...  

The performance of nanofiltration (NF) and ultrafiltration (UF) membranes was studied for separating hemicelluloses from a highly alkaline industrial stream, containing 17-18 wt% sodium hydroxide, resulting from the viscose process. Initially, screening experiments were performed to select suitable membranes, which were then investigated on a pilot scale spiral module. Screening experiments showed that the UF membrane, with a nominal molecular weight cut-off (MWCO) value of 3 kDa, and the NF one, with a nominal MWCO value of 0.5 kDa, showed a similar range of filtration performance and a flux of 4.2 L/m2.h. Further, a retention efficiency of 50% was observed for the 5 kDa and the 10 kDa membranes, indicating absence of any significant proportion of hemicelluloses in this range of molecular weights. The effects of process conditions were studied to understand their correlation with membrane performance with respect to hemicelluloses retention and permeate flux. UF membranes were found to be more prone to performance deterioration over time and with the number of cycles of usage during the pilot scale study, whereas the NF membrane showed consistent performance. It was seen that feed dilution can improve the membrane performance with respect to sodium hydroxide recovery. Significant reduction in feed viscosity with dilution resulted in a 50% increase in flux after normalizing for concentration.



2011 ◽  
Vol 221 ◽  
pp. 37-42 ◽  
Author(s):  
Feng Ma ◽  
Yu Zhong Zhang ◽  
Xiao Li Ding ◽  
Li Gang Lin ◽  
Hong Li

Polyethersulfone(PES)/Sulfonated polysulfone(SPSF) blend ultrafiltration membranes at different SPSF contents were prepared using a phase inversion technique. The morphological structures of PES/SPSF blend ultrafiltration membranes with different sulfonation degree were characterized using SEM. The results shown that the PES/SPSF blend ultrafiltration membranes had good retention to PEG1000 (99.8%) and high water permeate flux (27.2Lm-2h-1) at 0.1MPa.



2021 ◽  
Vol 8 (1) ◽  
pp. 25-32
Author(s):  
Fatemeh Darbandi ◽  
Azadeh Mousavi ◽  
Tayebe Bagheri Lotfabad ◽  
Amir Heydarinasab ◽  
Soheila Yaghmaei

Background: Recently, concerns have been raised regarding the environmental and public health safety of azo dyes, the most widely used synthetic dyes. The membrane technique has been introduced as one of the efficient methods for dye removal treatments. Polyvinylidene fluoride (PVDF) membrane manipulated by surfactants was studied for removal of the azo dye, carmoisine. Methods: PVDF membrane was prepared via non-solvent-induced phase separation (NIPS) and used to remove the azo dye, carmoisine. Three nonionic surfactants including Tween 20, Tween 60, and Tween 80 were used individually as additives in casting solutions to improve PVDF membrane properties. Results: Fourier-transform infrared spectroscopy (FTIR) demonstrated the presence of functional groups of carbonyl (C=O) and hydroxyl (OH), assigned to Tween molecules, in the membrane chemical structure. All Tween species caused a decrease in the surface hydrophobicity of PVDF membranes illustrated by the reduced contact angles. Each Tween at a 2% concentration in the dope solution led to an increase in the pore-size of PVDF membranes, which was estimated by scanning electron microscopy (SEM). However, this impact was reversed at Tween concentrations of 4%. Membranes were assessed for dye removal efficiency and permeate flux in a cross-flow system. Permeability of PVDF membranes improved (~78%) with adding Tween 80 at a concentration of 2%. Tween 60 at a 2% concentration resulted in a ~45% increase in dye removal efficiency of PVDF membranes. And, atomic force microscopy (AFM) showed that Tween 60 increased membrane surface roughness. Conclusion: Surfactant-mediated changes in the surface properties of PVDF membrane improved dye removal efficacy.



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