scholarly journals High Selective Composite Polyalkylmethylsiloxane Membranes for Pervaporative Removal of MTBE from Water: Effect of Polymer Side-chain

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1213
Author(s):  
Ilya Borisov ◽  
Ivan Podtynnikov ◽  
Evgenia Grushevenko ◽  
Olga Scharova ◽  
Tatiana Anokhina ◽  
...  
Keyword(s):  
Composite Membrane ◽  
Separation Factor ◽  
Concentration Polarization ◽  
Composite Membranes ◽  
Methyl Tert Butyl Ether ◽  
Side Chain ◽  
Butyl Ether ◽  
Water Separation ◽  
Selective Layer ◽  
First Time

For the first time, the effect of the side-chain in polyalkylmethylsiloxane towards pervaporative removal of methyl tert-butyl ether (MTBE) from water was studied. The noticeable enhancement of separation factor during the pervaporation of 1 wt.% MTBE solution in water through the dense film (40–50 µm) can be achieved by substitution of a methyl group (separation factor 111) for heptyl (161), octyl (169) or decyl (180) one in polyalkylmethylsiloxane. Composite membrane with the selective layer (~8 µm) made of polydecylmethylsiloxane (M10) on top of microfiltration support (MFFK membrane) demonstrated MTBE/water separation factor of 310, which was 72% greater than for the dense film (180). A high separation factor together with an overall flux of 0.82 kg·m−2·h−1 allowed this M10/MFFK composite membrane to outperform the commercial composite membranes. The analysis of the concentration polarization modulus and the boundary layer thickness revealed that the feed flow velocity should be gradually increased from 5 cm·s−1 for an initial solution (1 wt.% of MTBE in water) to 13 cm·s−1 for a depleted solution (0.2 wt.% of MTBE in water) to overcome the concentration polarization phenomena in case of composite membrane M10/MFFK (Texp = 50 °C).

scholarly journals Mesoporous Silica Membranes Silylated by Fluorinated and Non-Fluorinated Alkylsilanes for the Separation of Methyl Tert-Butyl Ether from Water

Membranes ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 70 ◽  
Author(s):  
Zhaojia Wang ◽  
Liwei Hao ◽  
Feihua Yang ◽  
Qi Wei
Keyword(s):  
Separation Factor ◽  
Total Flux ◽  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Silica Membrane ◽  
Water Separation ◽  
Silica Membranes ◽  
Tert Butyl ◽  
Carbon Chains ◽  
Fluorinated Carbon

It is of great significance to separate hazardous methyl tert-butyl ether (MTBE) from water in terms of environmental protection and human health. In the present work, α-Al2O3-suppotred silica membranes were prepared by the sol-gel and dip-coating technique. Two fluorinated alkylsilanes (1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTES) and trifluoropropyltriethoxysilane (TFPTES)) and two non-fluorinated alkylsilanes (octyltriethoxysilane (OTES) and propyltriethoxysilane (PTES)) were adopted to silylate the silica membrane by the post-grafting method which is used for the separation of MTBE from water by pervaporation. The results show that silylation enhances the hydrophobicity of silica membranes. The silylated silica membranes are selective towards MTBE, and the MTBE/water separation factor varies with grafting agents in the order: PFOTES > TFPTES > OTES > PTES. Membranes silylated with fluorinated carbon chains seem to be more selective towards MTBE than those with non-fluorinated carbon chains. The total flux is proportional to the pore volume of silica membranes, which depends on grafting agents in the order: PTES > PFOTES > OTES > TFPTES. Considering both total flux and selectivity, the PFOTES-SiO2 membrane is most effective in separation, with a MTBE/water separation factor of 24.6 and a total flux of 0.35 kg m−2 h−1 under a MTBE concentration of 3.0% and a feed temperature of 30 °C.

scholarly journals Blended Chitosan and Polyvinyl Alcohol Membrane for Pervaporation Separation Methanol/Methyl tert-Butyl Ether Mixture. (II) Effect of Operating Parameters

2013 ◽  
Vol 65 (1) ◽  
Author(s):  
M. G. Mohd Nawawi ◽  
Zafifah Zamrud ◽  
Z. Idham ◽  
O. Hassan ◽  
N. Mohd Sakri
Keyword(s):  
Polyvinyl Alcohol ◽  
Separation Factor ◽  
Composite Membranes ◽  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Blend Membrane ◽  
Membrane Flux ◽  
Ether Mixture ◽  
Feed Temperature ◽  
Pervaporation Separation

Blend chitosan and polyvinyl alcohol (PVA) composite membranes were developed by mixing PVA and chitosan solutions at appropriate ratios. Pervaporation separation of the membrane was tested for methanol and MTBE mixture at different feed concentrations and temperature. The pervaporation performances were studied and evaluated and compared to the composite chitosan membrane. Flux increased with the increasing concentration of methanol in the feed. Separation factor was highest for the 20 wt% chitosan-containing blend membrane. The blend membrane containing 20-40 wt% of chitosan at feed temperature of 50⁰C exhibited permeation flux in between 52.28 g/m2.hr to 66.92 g/m2.hr with the separation factor of 53.22 to 81.00. 

Preparation of NaA/PTFE Composite Membrane for Separation of DMF/H2O Mixture by Pervaporation

2011 ◽  
Vol 239-242 ◽  
pp. 2624-2627
Author(s):  
Hui Shao ◽  
Huan Ru Zhang ◽  
Qi Zhang ◽  
Guang Lu Han ◽  
Ruo Yu Chen ◽  
...  
Keyword(s):  
Composite Membrane ◽  
Separation Factor ◽  
Secondary Growth ◽  
Composite Membranes ◽  
Zeolite Crystal ◽  
Ptfe Film ◽  
Ptfe Composite ◽  
Structure And Morphology

The NaA/PTFE composite membranes were synthesized on polytetrafluoroethylene (PTFE) film by hydrothermal secondary growth (HSG) method and scratching (ST) method. The structure and morphology were characterized by XRD and SEM. The pervaporation(PV) performance of NaA/PTFE composite membranes were evaluated with dimethylformamide (DMF)/water mixtures. The XRD results showed that NaA/PTFE composite membranes kept the zeolite crystal feature of A type. The substrate, PTFE and zeolite were firmly combined together by the SEM photos. The results of PV showed that the flux and the separation factor of NaA/PTFE composite membrane prepared by HSG method with 4 crystallization times were 0.54 kg/m2 h and 23, respectively. The flux of NaA/PTFE composite membrane prepared by ST method was much larger than that of NaA/PTFE composite membrane prepared by HSG method, but separation factor was lower.

Composite Chitosan Membranes for the Separation of Methanol/methyl tert-butyl Ether Mixtures

2014 ◽  
Vol 67 (2) ◽  
Author(s):  
Mohd Ghazali Mohd Nawawi ◽  
Zafifah Zamrud
Keyword(s):  
Surface Morphology ◽  
Composite Membranes ◽  
Operating Conditions ◽  
Methanol Concentration ◽  
Methyl Tert Butyl Ether ◽  
Optimum Operating ◽  
Butyl Ether ◽  
Tert Butyl ◽  
Separation Factors ◽  
Swelling Characteristics

Composite membranes from chitosan blended with different ratios of chitosan were developed for the pervaporation of methanol/methyl tert-butyl ether mixtures. The composite membranes were characterized for surface morphology and sorption. Surface morphology showed chitosan and PVA were homogenously blend for all chitosan composition. Swelling characteristics of composites membrane were affected by methanol concentration as well as chitosan composition in the blend. Increasing feed temperatures and methanol concentration in the feed in pervaporation increased the flux and decreased the separation factor. The composite membranes containing 20 to 40 wt% chitosan was chosen as the preferred membrane formulation to yield fluxes ranging from 50 to 70 g/m2hr with separation factors ranging from 55 to 80 at optimum operating conditions of 30 wt% methanol in the feed and feed temperature of 50 0C.

scholarly journals Pressure effect during the formation of a selective layer on the structure and performance of dynamic composite membranes for pervaporation

2021 ◽  
Vol 65 (4) ◽  
pp. 431-438
Author(s):  
K. S. Burts ◽  
T. V. Plisko ◽  
A. V. Bildyukevich ◽  
G. Li ◽  
J. Kujawa ◽  
...  
Keyword(s):  
Contact Angle ◽  
Polymer Matrix ◽  
Composite Membrane ◽  
Substrate Surface ◽  
Composite Membranes ◽  
Feed Solution ◽  
Porous Membrane ◽  
Transmembrane Pressure ◽  
Dynamic Mode ◽  
Selective Layer

Composite membranes for pervaporation were prepared by forming a selective layer based on cross-linked polyvinyl alcohol (PVA) on the porous membrane-substrate surface in the dynamic mode (via PVA solution ultrafiltration). It was found that the pressure growth results in increasing the thickness of the composite membrane selective layer. Composite membrane contact angle, flux, water content in permeate in ethanol/water (mass ratio 90/10) pervaporation were revealed to have maximum values at 3–4 atm depending on the PVA concentration in the feed solution. It was shown that the revealed dependence of the contact angle, selectivity, and permeability on the pressure of the selective layer formation is due to the compaction of the polymer matrix-substrate under the action of the transmembrane pressure and its relaxation after pressure release. When using elevated pressures (more than 3–4 atm), the relaxation of the polymer matrix causes the microdefect to form as a result of deformation of the selective layer.

Polyion Complex Chitosan Membrane Consisting of Sodium Alginate/Chitosan for the Pervaporation Separation of Methanol/Methyl tert-butyl Ether Mixtures

2013 ◽  
Vol 66 (1) ◽  
Author(s):  
M. G. Mohd Nawawi ◽  
Zafifah Zamrud
Keyword(s):  
Sodium Alginate ◽  
Composite Membranes ◽  
Methyl Tert Butyl Ether ◽  
Separation Performance ◽  
Butyl Ether ◽  
Polyion Complex ◽  
Tert Butyl ◽  
Swelling Characteristics ◽  
Separation Performances ◽  
Feed Temperature

The polyion complex (PIC) composite membranes consisting of chitosan (CS) and sodium alginate (SA) were prepared for the separation of methanol/methyl tert-butyl ether (MTBE) mixtures via pervaporation process. Membrane morphologies showed that CS and SA were homogenously intermixed for all blended ratio tested. Swelling characteristics observed all membranes were readily swelled in the solution mixtures containing more methanols. Separation performance of the membranes via pervaporation was performed on the effect of SA composition in the membrane blend, effect of MTBE concentration in the feed and effect of feed temperature. Overall separation performances showed that the membranes were highly permselective towards methanol due to the affinity and polarity for all the studied parameters. 

Improving CO2 permeability of ceramic hollow fibre-supported composite membranes by blending an ionic liquid in the Pebax/PEGDME selective layer

RSC Advances ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 2055-2064 ◽  
Author(s):  
Jun Cheng ◽  
Leiqing Hu ◽  
Yannan Li ◽  
Chaofan Ji ◽  
Junhu Zhou ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Composite Membrane ◽  
Composite Membranes ◽  
Hollow Fibre ◽  
Permeation Rate ◽  
Selective Layer

The ionic liquid [P66614][2-Op], with high CO2 capacity, was blended in the Pebax/PEGDME selective layer of the ceramic hollow fibre-supported composite membrane. CO2 permeation rate was improved by ~35% and high CO2/H2 selectivity was maintained.

Cyclodextrin-based supramolecular polymeric nanoparticles for next generation gas separation membranes

2015 ◽  
Vol 3 (28) ◽  
pp. 14876-14886 ◽  
Author(s):  
Shereen Tan ◽  
Qiang Fu ◽  
Joel. M. P. Scofield ◽  
Jinguk Kim ◽  
Paul A. Gurr ◽  
...  
Keyword(s):  
Gas Separation ◽  
Gas Transport ◽  
Polymeric Nanoparticles ◽  
Composite Membranes ◽  
Dynamic Nature ◽  
Selective Layer ◽  
Separation Membranes ◽  
Gas Separation Membranes ◽  
First Time ◽  
Nanoparticle Additives

Cyclodextrin-based supramolecular polyrotaxanes are for the first time used as soft nanoparticle additives for the selective layer of composite membranes. They exhibit outstanding gas transport characteristics at low additive percentages, due to the dynamic nature of the PDMS side chains.

scholarly journals Influence of Spin Coating Parameters on Gas Transport Properties of Thin-Film Composite Membranes

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5093
Author(s):  
Stepan Sokolov ◽  
Alexey Balynin ◽  
Danila Bakhtin ◽  
Ilya Borisov
Keyword(s):  
Transport Properties ◽  
Penetration Depth ◽  
Spin Coating ◽  
Rotation Speed ◽  
Composite Membranes ◽  
Selective Layer ◽  
Thin Film Composite ◽  
Film Forming ◽  
Coating Method ◽  
First Time

The influence of casting centrifugation process parameters, such as a rotation speed (ω), the amount of the film-forming solution (V), and its concentration (C) on transport properties of composite membranes were investigated. A number of composite membranes based on poly (1-trimethylsilylpropyne) (PTMSP) and micro- (MFFK-1) and ultrafiltration (UFFK) membranes were obtained using the spin-coating method. For the first time, an unexpected dependence of permeance and ideal selectivity on rotation speed had been discovered: the thickness of the selective layer decreases from 3.0 to 1.0 μm for MFFK-1 and from 1.7 to 1.1 μm for UFFK with an increase of spin coater rotation speed from 500 to 3000 rpm. However, the gas permeance of composite membranes in the range of 500–2000 rpm was reduced due to an increase of a penetration depth of PTMSP into a support layer porous structure (estimated by the EDX method). The permeance of the PTMSP/UFFK membranes was higher than PTMSP/MFFK-1 membranes due to a thinner selective layer and a lower penetration depth of polymer solution into the pores of the support. The highest CO2/N2 selectivity values were achieved as 5.65 ± 0.9 at CO2 permeance 5600 ± 1000 GPU for PTMSP/UFFK membranes (CPTMSP = 0.35%, Vsolution = 1 mL, ω = 1000 rpm), and 6.1 ± 0.5 at CO2 permeance 4090 ± 500 GPU for PTMSP/MFFK-1 membranes (CPTMSP = 0.35%, Vsolution = 1 mL, ω = 2000 rpm).

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