Nanocellulose as Modifier for Hollow Fiber Ultrafiltration PSF Membranes

2019 ◽  
Vol 816 ◽  
pp. 238-243 ◽  
Author(s):  
Tatyana S. Anokhina ◽  
S.D. Bazhenov ◽  
Ilya L. Borisov ◽  
V.P. Vasilevsky ◽  
V.A. Vinokurov ◽  
...  
Keyword(s):  
Transport Properties ◽  
Hollow Fiber ◽  
Cellulose Nanofibrils ◽  
Membrane Modification ◽  
Selective Layer ◽  
Blue Dextran ◽  
First Time ◽  
Molding Solution

In the present work, a study was conducted for the first time on the modification of hollow fiber UF PSF membranes by cellulose nanofibrils. Two approaches to membrane modification were analyzed: 1) introduction of CNF into the molding solution; 2) additions of CNF to the internal coagulant. Analysis of the transport properties of the investigated membranes showed that the first approach allows increasing the porosity of hollow fiber PSF membranes, due to which the permeability increases from 82 to 287 l / m2 h bar compared to the original membranes. Rejection of dye Blue Dextran (MM = 69 kg / mole) is reduced by 20%. The addition of CNF to the outside coagulant led to the formation of not only the inside selective layer, but also the outer one, while the permeability increases 1.5 times, and the rejection of the dye also increases from 96 to 99%.

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).

scholarly journals Effect of Temperature Exposition of Casting Solution on Properties of Polysulfone Hollow Fiber Membranes

Fibers ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 110 ◽  
Author(s):  
Ilya Borisov ◽  
Vladimir Vasilevsky ◽  
Dmitry Matveev ◽  
Anna Ovcharova ◽  
Alexey Volkov ◽  
...  
Keyword(s):  
Phase Separation ◽  
Thermal Treatment ◽  
Transport Properties ◽  
Hollow Fiber ◽  
Treatment Time ◽  
Solution Viscosity ◽  
Oxidative Destruction ◽  
Hollow Fiber Membranes ◽  
Selective Layer ◽  
Casting Solution

It was shown for the first time that the conditions of thermal treatment of the casting solution significantly affect the morphology and transport properties of porous, flat, and hollow fiber polysulfone (PSf) membranes. It is ascertained that the main solution components that are subjected to thermo-oxidative destruction are the pore-forming agent polyethylene glycol (PEG) and solvent N-methyl-2-pyrrolidone (NMP). It is proved that hydroxyl groups of PEG actively react in the process of the casting solution thermo-oxidative destruction. It is shown that despite the chemical conversion taking place in the casting solution, their stability towards coagulation virtually does not change. The differences in the membrane morphology associated with the increase of thermal treatment time at 120 °C are not connected to the thermodynamic properties of the casting solutions, but with the kinetics of the phase separation. It is revealed that the change of morphology and transport properties of membranes is connected with the increase of the casting solution viscosity. The rise of solution viscosity resulted in the slowdown of the phase separation and formation of a more densely packed membrane structure with less pronounced macropores. It is determined experimentally that with the increase of casting solution thermal treatment time, the membrane selective layer thickness increases. This leads to the decrease of gas permeance and the rise of the He/CO2 selectivity for flat and hollow fiber membranes. In the case of hollow fibers, the fall of gas permeance is also connected with the appearance of the sponge-like layer at the outer surface of membranes. The increase of selectivity and decline of permeance indicates the reduction of selective layer pore size and its densification, which agrees well with the calculation results of the average membrane density. The results obtained are relevant to any polymeric casting solution containing NMP and/or PEG and treated at temperatures above 60 °C.

Influence of Casting Method on Pervaporational Performanses of Polyheptylmethylsiloxane Membranes

2020 ◽  
Vol 869 ◽  
pp. 51-55
Author(s):  
Evgenia Grushevenko ◽  
Ivan A. Podtynnikov ◽  
Olga Sharova ◽  
Tatiana Anokhina ◽  
Ilya L. Borisov
Keyword(s):  
Transport Properties ◽  
Composite Membrane ◽  
Spin Coating ◽  
Casting Method ◽  
Selective Layer ◽  
Spin Coating Method ◽  
Coating Method ◽  
Membrane Pervaporation ◽  
First Time

A method of composite membrane obtaining effects on its transport properties. In the present work, for the first time, the influence of the method of applying a selective layer of polyheptylmethylsiloxane on the composite membrane pervaporation properties in the process of alcohol separation from water was studied. The comparison of two casting methods (kiss-coating and spin-coating) was conducted. Morphology of the obtained membranes and their separation properties during the pervaporation of the mixture of C2-C4 alcohols and water. It was shown that kiss-coating allows completely prevent leakage of the selective layer into the substrate pores. And, such a way, it allows to improve permeability of composite membrane (BuOH - 3.5 mol/(kPa·h·m2)). Besides, spin-coating method leads to higher selectivity (BuOH/H2O - 2.3). It is caused by blocking the swelling of that part of the selective layer that is locked in the pores of the substrate. Thus, the choice of the casting method can determine the compatibility of the composite membrane with a specific separation task.

Graphite/UPE Nanocomposite: Transport, Thermal, Mechanical and Viscoelastic Properties

2019 ◽  
Vol 23 ◽  
pp. 201-212
Author(s):  
Shivkumari Panda ◽  
Dibakar Behera ◽  
Tapan Kumar Bastia
Keyword(s):  
Transport Properties ◽  
Unsaturated Polyester ◽  
Homogeneous Distribution ◽  
Thermo Gravimetric ◽  
New Class ◽  
The Matrix ◽  
Novel Method ◽  
Water Transport Properties ◽  
First Time

This chapter presents the preparation and characterization of some unique properties of nanocomposites by dispersing graphite flakes in commercial unsaturated polyester (UPE) matrix. The composite was prepared by a novel method with the use of solvent swelling technique. Three different specimens of UPE/graphite nanocomposites were fabricated with addition of 1, 2 and 3 wt% of graphite flakes. Except mechanical, viscoelastic and thermo gravimetric properties, transport properties like electrical conductivity, thermal conductivity and water transport properties were studied for the first time. Graphite flakes propose enhanced properties to the composites suggesting homogeneous distribution of the nanofiller in the matrix and strong interaction with the matrix. 2wt% nanofiller loading showed superior essential characteristics and after that the properties reduced may be due to the nucleating tendency of the nanofiller particles. The XRD pattern showed the compatibility of the graphite flakes by introducing a peak around 26.550 in the nanocomposites. SEM Properties are also in agreement with the compatibility. Nanocomposite with 2wt% graphite also showed remarkable enhancement in transport, mechanical, viscoelastic and thermo gravimetric properties. So by introduction of a small quantity of graphite endow the new class of multiphase nanocomposites with inimitable structure and tremendous application.

scholarly journals Development of Antifouling Polysulfone Membranes by Synergistic Modification with Two Different Additives in Casting Solution and Coagulation Bath: Synperonic F108 and Polyacrylic Acid

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 359
Author(s):  
Katsiaryna S. Burts ◽  
Tatiana V. Plisko ◽  
Mikael Sjölin ◽  
Goncalo Rodrigues ◽  
Alexandr V. Bildyukevich ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Polyacrylic Acid ◽  
Process Water ◽  
Coagulation Bath ◽  
Interpolymer Complex ◽  
Polypropylene Glycol ◽  
Layer Surface ◽  
Membrane Modification ◽  
Selective Layer ◽  
Casting Solution

This study deals with the development of antifouling ultrafiltration membranes based on polysulfone (PSF) for wastewater treatment and the concentration and purification of hemicellulose and lignin in the pulp and paper industry. The efficient simple and reproducible technique of PSF membrane modification to increase antifouling performance by simultaneous addition of triblock copolymer polyethylene glycol-polypropylene glycol-polyethylene glycol (Synperonic F108, Mn =14 × 103 g mol−1) to the casting solution and addition of polyacrylic acid (PAA, Mn = 250 × 103 g mol−1) to the coagulation bath is proposed for the first time. The effect of the PAA concentration in the aqueous solution on the PSF/Synperonic F108 membrane structure, surface characteristics, performance, and antifouling stability was investigated. PAA concentrations were varied from 0.35 to 2.0 wt.%. Membrane composition, structure, and topology were investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The addition of PAA into the coagulation bath was revealed to cause the formation of a thicker and denser selective layer with decreasing its pore size and porosity; according to the structural characterization, an interpolymer complex of the two additives was formed on the surface of the PSF membrane. Hydrophilicity of the membrane selective layer surface was shown to increase significantly. The selective layer surface charge was found to become more negative in comparison to the reference membrane. It was shown that PSF/Synperonic F108/PAA membranes are characterized by better antifouling performance in ultrafiltration of humic acid solution and thermomechanical pulp mill (ThMP) process water. Membrane modification with PAA results in higher ThMP process water flux, fouling recovery ratio, and hemicellulose and total lignin rejection compared to the reference PSF/Synperonic F108 membrane. This suggests the possibility of applying the developed membranes for hemicellulose concentration and purification.

scholarly journals Novel Composite Membranes Based on Chitosan Copolymers with Polyacrylonitrile and Polystyrene: Physicochemical Properties and Application for Pervaporation Dehydration of Tetrahydrofuran

Membranes ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 38 ◽  
Author(s):  
Ksenia Otvagina ◽  
Anastasia Penkova ◽  
Maria Dmitrenko ◽  
Anna Kuzminova ◽  
Tatyana Sazanova ◽  
...  
Keyword(s):  
Transport Properties ◽  
Optimal Transport ◽  
Mechanical Stability ◽  
Evolved Gas Analysis ◽  
Composite Membranes ◽  
Gas Analysis ◽  
Vinyl Monomers ◽  
Porous Support ◽  
Selective Layer ◽  
Force Microscopy

Pervaporation has been applied for tetrahydrofuran (THF) dehydration with novel composite membranes advanced by a thin selective layer composed of chitosan (CS) modified by copolymerization with vinyl monomers, acrylonitrile (AN) and styrene, in order to improve the chemical and mechanical stability of CS-based membranes. Composite membranes were developed by depositing a thin selective layer composed of CS copolymers onto a commercially-available porous support based on aromatic polysulfonamide (UPM-20®). The topography and morphology of the obtained materials were studied by atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). Thermal properties and stability were determined by coupled evolved gas analysis (EGA-MS). Transport properties were estimated in pervaporation dehydration of THF. The effect of operating parameters for the pervaporation dehydration of THF such as feed compositions and temperatures (295, 308 and 323 K) was evaluated. It was shown that CS modification with different vinyl monomers led to a difference in physical and transport properties. The composite membrane with the thin selective layer based on CS-PAN copolymer demonstrated optimal transport properties and exhibited the highest water content in the permeate with a reasonably high permeation flux.

scholarly journals Synthesis, transport properties and electronic structure of p-type Cu1+xMn2−xInTe4 (x = 0, 0.2, 0.3)

2020 ◽  
Vol 49 (7) ◽  
pp. 2273-2279 ◽  
Author(s):  
Dean Hobbis ◽  
Wencong Shi ◽  
Adrian Popescu ◽  
Kaya Wei ◽  
Ryan E. Baumbach ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Transport Properties ◽  
Temperature Dependent ◽  
Dependent Transport ◽  
P Type ◽  
First Time

The synthesis, electronic structure and temperature dependent transport properties of polycrystalline Cu1+xMn2−xInTe4 (x = 0, 0.2, 0.3) are reported for the first time.

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