Joanna Kujawa - Academia.edu (original) (raw)

Papers by Joanna Kujawa

Materials, 2022

A strategy for the bioconjugation of the enzyme Candida antarctica lipase B onto titania ceramic ... more A strategy for the bioconjugation of the enzyme Candida antarctica lipase B onto titania ceramic membranes with varied pore sizes (15, 50, 150, and 300 kDa) was successfully performed. The relationship between the membrane morphology, i.e.,the pore size of the ceramic support, and bioconjugation performance was considered. Owing to the dimension of the enzyme (~33 kDa), the morphology of the ceramics allowed (50, 150, and 300 kDa) or did not allow (15 kDa) the entrance of the enzyme molecules into the porous structure. Such a strategy made it possible to better understand the changes in the material (morphology) and physicochemical features (wettability, adhesiveness, and surface charge) of the samples, which were systematically examined. The silane functionalization and enzyme immobilization were accomplished via the covalent route. The samples were characterized after each stage of the modification, which was very informative from the material point of view. As a consequence of th...

Polymers, 2021

The development of thin layer on hollow-fiber substrate has drawn great attention in the gas-sepa... more The development of thin layer on hollow-fiber substrate has drawn great attention in the gas-separation process. In this work, polydimethysiloxane (PDMS)/polyetherimide (PEI) hollow-fiber membranes were prepared by using the dip-coating method. The prepared membranes were characterized by Scanning Electron Microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), and gas permeance measurements. The concentration of PDMS solution and coating time revealed an important influence on the gas permeance and the thickness of the PDMS layer. It was confirmed from the SEM and EDX results that the PDMS layer’s thickness and the atomic content of silicon in the selective layer increased with the growth in coating time and the concentration of PDMS solution. The composite hollow-fiber membrane prepared from 15 wt% PDMS solution at 10 min coating time showed the best gas-separation performance with CO2 permeance of 51 GPU and CO2/N2 ideal selectivity of 21.

Membranes, 2022

Porous polyamide-6 membranes were fabricated via a non-solvent induced phase inversion method, an... more Porous polyamide-6 membranes were fabricated via a non-solvent induced phase inversion method, and the influence of gelation time on the properties of the membranes was investigated. Membrane samples with various gelation times were prepared. The evaluation of the membranes’ properties was carried out by various analyses and tests, such as scanning electron microscopy, atomic force microscopy, contact angle, wet and dry thickness, mean pore size measurements, porosity, water uptake, mechanical resistance, hydrodynamic water fluxes, membrane hydrodynamic permeability, and retention testing. The scanning electron microscopy images (both surface and cross-section) demonstrated that the increase in gelation time from 0 (M0) to 10 (M10) min led to the morphological change of membranes from isotropic (M0) to anisotropic (M10). The wet and dry thickness of the membranes showed a downward tendency with increasing gelation time. The M0 membrane exhibited the lowest bubble contact angle of 60...

Materials, 2021

Membrane separation technology can used to capture carbon dioxide from flue gas. However, plenty ... more Membrane separation technology can used to capture carbon dioxide from flue gas. However, plenty of research has been focused on the flat sheet mixed matrix membrane rather than the mixed matrix thin film hollow fiber membranes. In this work, mixed matrix thin film hollow fiber membranes were fabricated by incorporating amine functionalized UiO-66 nanoparticles into the Pebax® 2533 thin selective layer on the polypropylene (PP) hollow fiber supports via dip-coating process. The attenuated total reflection-Fourier transform infrared (ATR-FTIR), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX) mapping analysis, and thermal analysis (TGA-DTA) were used to characterize the synthesized UiO-66-NH2 nanoparticles. The morphology, surface chemistry, and the gas separation performance of the fabricated Pebax® 2533-UiO-66-NH2/PP mixed matrix thin film hollow fiber membranes were characterized by using SEM, ATR-FTIR, and gas permeance measurements, respectively. It...

International Journal of Molecular Sciences, 2021

Today, the use of polymer electrolyte membranes (PEMs) possessing ionic liquids (ILs) in middle a... more Today, the use of polymer electrolyte membranes (PEMs) possessing ionic liquids (ILs) in middle and high temperature polymer electrolyte membrane fuel cells (MT-PEMFCs and HT-PEMFCs) have been increased. ILs are the organic salts, and they are typically liquid at the temperature lower than 100 °C with high conductivity and thermal stability. The membranes containing ILs can conduct protons through the PEMs at elevated temperatures (more than 80 °C), unlike the Nafion-based membranes. A wide range of ILs have been identified, including chiral ILs, bio-ILs, basic ILs, energetic ILs, metallic ILs, and neutral ILs, that, from among them, functionalized ionic liquids (FILs) include a lot of ion exchange groups in their structure that improve and accelerate proton conduction through the polymeric membrane. In spite of positive features of using ILs, the leaching of ILs from the membranes during the operation of fuel cell is the main downside of these organic salts, which leads to reducing...

Sustainability, 2021

Elderberry fruits contain valuable components that are beneficial to human health. Owing to the h... more Elderberry fruits contain valuable components that are beneficial to human health. Owing to the high content of anthocyanins, elderberry extracts can be used as natural food colorants with health-promoting properties. Moreover, the development of new natural food dyes enables the reduction in the use of synthetic ones. Anthocyanins-rich elderberry dry extracts (EDE) were prepared from the same batch of frozen fruits applying water extraction, followed by membrane separation (batch B1) or purification by column chromatography (batch B2) and then spray-dried. Subsequently, the content of anthocyanins, flavonols, and polyphenols was determined. The extract obtained with the application of column chromatography (B2) contained 33% anthocyanins, which is more than typical market standards, whereas the extract B1 contained 14% anthocyanins. The color properties of both extracts were also determined. Since water was used as an extractant, the extracts are well soluble in water and can there...

Materials, 2021

A highly effective method was developed to functionalize ceramic supports (Al2O3 powders and memb... more A highly effective method was developed to functionalize ceramic supports (Al2O3 powders and membranes) using newly synthesized spacer molecules. The functionalized materials were subsequently utilized for Candida antarctica lipase B enzyme immobilization. The objective is to systematically evaluate the impact of various spacer molecules grafted onto the alumina materials will affect both the immobilization of the enzymes and specific material surface properties, critical to enzymatic reactors performance. The enzyme loading was significantly improved for the supports modified with shorter spacer molecules, which possessed higher grafting effectiveness on the order of 90%. The specific enzyme activity was found to be much higher for samples functionalized with longer modifiers yielding excellent enantioselectivity >97%. However, the enantiomeric ratio of the immobilized lipase was slightly lower in the case of shorter spacer molecules.

Doklady of the National Academy of Sciences of Belarus, 2021

Composite membranes for pervaporation were prepared by forming a selective layer based on cross-l... more 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...

Materials, 2020

Pervaporation is a membrane technique used to separate azeotropic and close boiling solvents. Het... more Pervaporation is a membrane technique used to separate azeotropic and close boiling solvents. Heterogenous PVA composite membranes with NaY zeolite supported on polyamide-6 were fabricated and utilized in organic–organic pervaporation. The efficiency of prepared membranes was evaluated in the separation of ethanol/ethyl tert-butyl ether (EtOH/ETBE) using separation factor (β) and the thickness normalized pervaporation separation index (PSIN). Implementation of the fringe projection phase-shifting method allowed to the determined contact angle corrected by roughness. The influence of the presence of water traces in the feed on the overall separation efficiency was also discussed using the enrichment factor for water (EFwater). The incorporation of NaY into PVA matrix increases surface roughness and hydrophilicity of the composite membrane. It was found that membranes selectively transport ethanol from the binary EtOH/ETBE mixture. The values of β (2.3) and PSIN (288 μm g m−2 h−1) for...

Polymers, 2020

A new type of hybrid polymeric-based film containing 1-(1,3-diethoxy-1,3-dioxopropan-2-ylo)-3-met... more A new type of hybrid polymeric-based film containing 1-(1,3-diethoxy-1,3-dioxopropan-2-ylo)-3-methylimidazolium bromide (RIL1_Br) and 1-(2-etoxy-2-oxoethyl)-3-methylimidazolium bromide (RIL2_Br) reactive ionic liquids was elaborated. Poly(vinyl alcohol) (PVA)-based films with 9–33 wt % of RILs were subsequently characterized using Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and TGA-FTIR. PVA-RIL films were also studied in tensile tests, contact angle and sorption measurements. RIL incorporation enhanced thermal and mechanical stability of PVA membranes due to the hydrogen bonds between RILs and polymer chains. Membrane swelling behavior in water (H2O), ethanol (EtOH), and propan-2-ol (IPA) and the kinetics of water sorption process revealed that PVA-RILs membranes possess the highest affinity towards water. It was pointed out that both the RIL...

Biomolecules, 2020

This short review analyzed the recent trend towards, progresses towards the preparation of chemic... more This short review analyzed the recent trend towards, progresses towards the preparation of chemicals of, and value-added biomaterials from marine macroalgae resources, especially green seaweeds and their derived ulvan polysaccharides for various applications. In recent years, ulvan both in pristine and modified forms has gained a large amount of attention for its effective utilization in various areas due to its unique physiochemical properties, lack of exploration, and higher green seaweed production. The pristine form of ulvan (sulfated polysaccharides) is used as a bio-component; food ingredient; or a raw material for the production of numerous chemicals such as fuels, cosmetics, and pharmaceuticals, whereas its modified form is used in the sector of composites, membranes, and scaffolds, among others, because of its physicochemical properties. This review highlights the utilization of green seaweed and its derived ulvan polysaccharides for the preparation of numerous chemicals (e...

Separation and Purification Technology, 2020

The PVDF membrane modification was performed utilizing the graphitic carbon nitride (g-C 3 N 4) i... more The PVDF membrane modification was performed utilizing the graphitic carbon nitride (g-C 3 N 4) in order to generate photocatalytic properties under visible light irradiation. Graphitic carbon nitride was synthesized via heating of melamine. Commercial PVDF ultrafiltration membranes with cutoff of 150 kDa were activated with a carbonate buffer and g-C 3 N 4 was subsequently attached by terminal amino groups. The structural and morphological properties of g-C 3 N 4 and membrane materials have been characterized using TEM, SEM-EDX, FTIR and EDX analysis. The adsorption of Rhodamine B and Rhodamine 6G on modified membranes and their subsequent degradation of dyes were studied. Membranes with immobilized g-C 3 N 4 possessed 10 times higher adsorption rate of Rhodamine 6G compared to Rhodamine B. The highest photocatalytic activity of modified membranes has been observed in alkaline media. Using isopropanol, tert-butylhydroquinone, potassium iodine and Cr(VI) as % OH, % O 2 − , h + and ē scavengers, it has been shown that the generated holes have been responsible for dyes degradation in acidic media and superoxide radicals in alkaline media, and both of them at neutral conditions. The transport through PVDF-g-C 3 N 4 membranes have been characterized by the volumetric flux of 320-350 L/(m 2 •h) during the ultrafiltration of dyes. Rejection of Rhodamine B and Rhodamine 6G was of 96 and 94%, respectively. The yield of dyes decomposition was about 80% and 85% for Rhodamine B and Rhodamine 6G, correspondingly, within the range of dye concentration from 5 to 50 mg/L. PVDF-g-C 3 N 4 membranes were characterized with high stability and reusability in process of dyes ultrafiltration in the crossflow mode. The loss of membrane activity after 5 cycles of ultrafiltration (total duration equal to 50 h) was approximately 15%.

Journal of Membrane Science, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Polymers, 2018

Pervaporation is a membrane-separation technique which uses polymeric and/or ceramic membranes. I... more Pervaporation is a membrane-separation technique which uses polymeric and/or ceramic membranes. In the case of pervaporation processes applied to dehydration, the membrane should transport water molecules preferentially. Reactive ionic liquid (RIL) (3-(1,3-diethoxy-1,3-dioxopropan-2-yl)-1-methyl-1H-imidazol-3-ium) was used to prepare novel dense cellulose acetate propionate (CAP) based membranes, applying the phase-inversion method. The designed polymer-ionic liquid system contained ionic liquid partially linked to the polymeric structure via the transesterification reaction. The various physicochemical, mechanical, equilibrium and transport properties of CAP-RIL membranes were determined and compared with the properties of CAP membranes modified with plasticizers, i.e., tributyl citrate (TBC) and acetyl tributyl citrate (ATBC). Thermogravimetric analysis (TGA) testified that CAP-RIL membranes as well as CAP membranes modified with TBC and ATBC are thermally stable up to at least 120 • C. Tensile tests of the membranes revealed improved mechanical properties reflected by reduced brittleness and increased elongation at break achieved for CAP-RIL membranes in contrast to pristine CAP membranes. RIL plasticizes the CAP matrix, and CAP-RIL membranes possess preferable mechanical properties in comparison to membranes with other plasticizers investigated. The incorporation of RIL into CAP membranes tuned the surface properties of the membranes, enhancing their hydrophilic character. Moreover, the addition of RIL into CAP resulted in an excellent improvement of the separation factor, in comparison to pristine CAP membranes, in pervaporation dehydration of propan-2-ol. The separation factor β increased from ca. 10 for pristine CAP membrane to ca. 380 for CAP-16.7-RIL membranes contacting an azeotropic composition of water-propan-2-ol mixture (i.e., 12 wt % water).

Materials (Basel, Switzerland), Jan 7, 2018

Advanced ceramic materials with a well-defined nano-architecture of their surfaces were formed by... more Advanced ceramic materials with a well-defined nano-architecture of their surfaces were formed by applying a two-step procedure. Firstly, a primary amine was docked on the ordered nanotubular ceramic surface via a silanization process. Subsequently, single-wall carbon nanotubes (SWCNTs) were covalently grafted onto the surface via an amide building block. Physicochemical (e.g., hydrophobicity, and surface free energy (SFE)), mechanical, and tribological properties of the developed membranes were improved significantly. The design, preparation, and extended characterization of the developed membranes are presented. Tools such as high-resolution transmission electron microscopy (HR-TEM), single-area electron diffraction (SAED) analysis, microscopy, tribology, nano-indentation, and Raman spectroscopy, among other techniques, were utilized in the characterization of the developed membranes. As an effect of hydrophobization, the contact angles (CAs) changed from 38° to 110° and f...

Applied Sciences, 2017

Hydrophilic ceramic membranes (tubular and planar) made of TiO 2 and Al 2 O 3 were efficiently mo... more Hydrophilic ceramic membranes (tubular and planar) made of TiO 2 and Al 2 O 3 were efficiently modified with non-fluorinated hydrophobic grafting molecules. As a result of condensation reaction between hydroxyl groups on the membrane and reactive groups of modifiers, the hydrophobic surfaces were obtained. Ceramic materials were chemically modified using three various non-fluorinated grafting agents. In the present work, the influence of grafting time and type of grafting molecule on the modification efficiency was evaluated. The changes of physicochemical properties of obtained hydrophobic surfaces were determined by measuring the contact angle (CA), roughness (RMS), and surface free energy (SFE). The modified surfaces were characterized by contact angle in the range of 111-132 •. Moreover, hydrophobic tubular membranes were utilized in air-gap membrane distillation to desalination of sodium chloride aqueous solutions. The observed permeate fluxes were in the range of 0.7-4.8 kg•m −2 •h −1 for tests with pure water. The values of permeate fluxes for membranes in contact with NaCl solutions were smaller, within the range of 0.4-2.8 kg•m −2 •h −1. The retention of NaCl in AGMD process using hydrophobized ceramic membranes was close to unity for all investigated membranes.

Journal of Membrane Science, 2016

Two ion-exchange membranes possessing perfluorinated backbone and sulfonic groups (i.e. Nafion s ... more Two ion-exchange membranes possessing perfluorinated backbone and sulfonic groups (i.e. Nafion s 120 and IonClad™ R4010) with lithium(I) counter-ions were investigated. The interactions between solvents of different polarity and the ion-exchange membranes with various morphologies were taken into account in order to better understand solvation and dissociation phenomena of the ion-pairs. Pervaporation of polar (i.e. water, methanol)-nonpolar (i.e. methyl acetate, dimethyl carbonate) liquid mixtures was carried out. It was revealed that the increase of the polar component concentration above 2 wt% in the feed mixture leads to dissociation of ion-pairs in Nafion membrane, which is reflected by the rapid increase of the polar component partial flux. In the case of IonClad membrane the dissociation of the ion-pairs during pervaporation was observed only when water was a polar feed component. The dissociation of ion-pairs was also evidenced in infrared study by observing the shift of symmetric stretching vibrations (ν s) bands of sulfonic groups to the lower wavenumbers, compared to the membrane in the dry state. The symmetric stretching vibrations (ν s) bands of the dry Nafion membrane and membrane solvated with water and methanol were equal to 1071 cm À 1 , 1058 cm À 1 , and 1054 cm À 1 , respectively. In the case of IonClad membrane the symmetric stretching vibration (ν s) bands changed in contact with water from 1047 cm À 1 (dry membrane) to 1037 cm À 1. The dissociation of the ion-pairs did not occur in IonClad membrane equilibrated with methanol, which is also consistent with the result obtained during pervaporation.

ACS Applied Materials & Interfaces, 2016

The combination of microscopic (atomic force microscopy and scanning electron microscopy) and gon... more The combination of microscopic (atomic force microscopy and scanning electron microscopy) and goniometric (static and dynamic measurements) techniques, and surface characterization (surface free energy determination, critical surface tension, liquid entry pressure, hydraulic permeability) was implemented to discuss the influence of perfluoroalkylsilanes structure and grafting time on the physicochemistry of the created hydrophobic surfaces on the titania ceramic membranes of 5 kD and 300 kD. The impact of molecular structure of perfluoroalkylsilanes modifiers (possessing from 6 to 12 carbon atoms in the fluorinated part of the alkyl chain) and the time of the functionalization process in the range of 5 to 35 h was studied. Based on the scanning electron microscopy with energy-dispersive X-ray spectroscopy, it was found that the localization of grafting molecules depends on the membrane pore size (5kD or 300kD). In the case of 5kD titania membranes, modifiers are attached mainly on the surface and only partially inside the membrane pores, whereas, for 300kD membranes, the perfluoroalkylsilanes molecules are present within the whole porous structure of the membranes. The application of 4 various types of PFAS molecules enabled for interesting observations and remarks. It was explained how to obtain ceramic membrane surfaces with controlled material (contact angle, roughness, contact angle hysteresis) and separation properties. Highly hydrophobic surfaces with low values of contact angle hysteresis and low roughness were obtained. These surfaces possessed also low values of critical surface tension, which means that surfaces are highly resistant to wetting. This finding is crucial in membrane applicability in separation processes. The obtained and characterized hydrophobic membranes were subsequently applied in air-gap membrane distillation processes. All membranes were very efficient in MD processes, showing good transport and selective properties (∼99% of NaCl salt rejection). Depending on the membrane pore size and used modifiers, the permeate flux was in the range of 0.5-4.5 kg·m(-2)·h(-1) and 0.3-4.2 kg·m(-2)·h(-1) for 5 kD and 300 kD membranes, respectively.

Ionics, 2015

The work is devoted to a computational study of three types of cationic polymeric membranes in Li... more The work is devoted to a computational study of three types of cationic polymeric membranes in Li +-ionic form, in water and methanol environments, at various solvation levels. The studied membranes Nafion, IonClad, and M3 possess the perfluorinated backbone; however, various side chains were terminated with the functional groups of distinctly different ionic strength. The paper discusses the structural features of the membrane-solvent clusters as well as an influence of the side chain nature on the dissociation of the functional groups and the binding energy of the solvent molecules. Additionally, the paper compares the obtained results for Li +-Nafion membrane in water with the results published earlier for H + and Na + forms.

Food and Bioprocess Technology, 2015

Hydrophobic polymeric membranes (PP, PTFE, and PVDF) were efficiently applied in juice concentrat... more Hydrophobic polymeric membranes (PP, PTFE, and PVDF) were efficiently applied in juice concentration by osmotic membrane distillation process at room temperature. The properties of applied membranes were characterized by the value of static contact angle, hysteresis of contact angle, surface free energy, roughness, mean flow pore size, maximum pore size or bubble point, and the pore size distribution before and after their utilization in osmotic membrane distillation (OMD). Furthermore, the mechanical strength of the membranes was evaluated using the Mullen burst technique and characterization of fouling behavior was done. The impact of stripping solutions, characterized by different water activities (NaCl and CaCl 2), type of membrane materials, and membrane morphology, on the transport properties in a dehydration process was evaluated. Apple and beet juices with a high level of antioxidants were chosen. The quality of juices has been assessed by determination of total polyphenols and antioxidant activity. In the dehydration process, the most efficient were 0.45-μm PTFE and 0.45-μm PVDF membranes (24 % improvement). No loss of polyphenol content or reduction of antioxidant activity was observed after the juice dehydration.

Materials, 2022

A strategy for the bioconjugation of the enzyme Candida antarctica lipase B onto titania ceramic ... more A strategy for the bioconjugation of the enzyme Candida antarctica lipase B onto titania ceramic membranes with varied pore sizes (15, 50, 150, and 300 kDa) was successfully performed. The relationship between the membrane morphology, i.e.,the pore size of the ceramic support, and bioconjugation performance was considered. Owing to the dimension of the enzyme (~33 kDa), the morphology of the ceramics allowed (50, 150, and 300 kDa) or did not allow (15 kDa) the entrance of the enzyme molecules into the porous structure. Such a strategy made it possible to better understand the changes in the material (morphology) and physicochemical features (wettability, adhesiveness, and surface charge) of the samples, which were systematically examined. The silane functionalization and enzyme immobilization were accomplished via the covalent route. The samples were characterized after each stage of the modification, which was very informative from the material point of view. As a consequence of th...

Polymers, 2021

The development of thin layer on hollow-fiber substrate has drawn great attention in the gas-sepa... more The development of thin layer on hollow-fiber substrate has drawn great attention in the gas-separation process. In this work, polydimethysiloxane (PDMS)/polyetherimide (PEI) hollow-fiber membranes were prepared by using the dip-coating method. The prepared membranes were characterized by Scanning Electron Microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), and gas permeance measurements. The concentration of PDMS solution and coating time revealed an important influence on the gas permeance and the thickness of the PDMS layer. It was confirmed from the SEM and EDX results that the PDMS layer’s thickness and the atomic content of silicon in the selective layer increased with the growth in coating time and the concentration of PDMS solution. The composite hollow-fiber membrane prepared from 15 wt% PDMS solution at 10 min coating time showed the best gas-separation performance with CO2 permeance of 51 GPU and CO2/N2 ideal selectivity of 21.

Membranes, 2022

Porous polyamide-6 membranes were fabricated via a non-solvent induced phase inversion method, an... more Porous polyamide-6 membranes were fabricated via a non-solvent induced phase inversion method, and the influence of gelation time on the properties of the membranes was investigated. Membrane samples with various gelation times were prepared. The evaluation of the membranes’ properties was carried out by various analyses and tests, such as scanning electron microscopy, atomic force microscopy, contact angle, wet and dry thickness, mean pore size measurements, porosity, water uptake, mechanical resistance, hydrodynamic water fluxes, membrane hydrodynamic permeability, and retention testing. The scanning electron microscopy images (both surface and cross-section) demonstrated that the increase in gelation time from 0 (M0) to 10 (M10) min led to the morphological change of membranes from isotropic (M0) to anisotropic (M10). The wet and dry thickness of the membranes showed a downward tendency with increasing gelation time. The M0 membrane exhibited the lowest bubble contact angle of 60...

Materials, 2021

Membrane separation technology can used to capture carbon dioxide from flue gas. However, plenty ... more Membrane separation technology can used to capture carbon dioxide from flue gas. However, plenty of research has been focused on the flat sheet mixed matrix membrane rather than the mixed matrix thin film hollow fiber membranes. In this work, mixed matrix thin film hollow fiber membranes were fabricated by incorporating amine functionalized UiO-66 nanoparticles into the Pebax® 2533 thin selective layer on the polypropylene (PP) hollow fiber supports via dip-coating process. The attenuated total reflection-Fourier transform infrared (ATR-FTIR), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX) mapping analysis, and thermal analysis (TGA-DTA) were used to characterize the synthesized UiO-66-NH2 nanoparticles. The morphology, surface chemistry, and the gas separation performance of the fabricated Pebax® 2533-UiO-66-NH2/PP mixed matrix thin film hollow fiber membranes were characterized by using SEM, ATR-FTIR, and gas permeance measurements, respectively. It...

International Journal of Molecular Sciences, 2021

Today, the use of polymer electrolyte membranes (PEMs) possessing ionic liquids (ILs) in middle a... more Today, the use of polymer electrolyte membranes (PEMs) possessing ionic liquids (ILs) in middle and high temperature polymer electrolyte membrane fuel cells (MT-PEMFCs and HT-PEMFCs) have been increased. ILs are the organic salts, and they are typically liquid at the temperature lower than 100 °C with high conductivity and thermal stability. The membranes containing ILs can conduct protons through the PEMs at elevated temperatures (more than 80 °C), unlike the Nafion-based membranes. A wide range of ILs have been identified, including chiral ILs, bio-ILs, basic ILs, energetic ILs, metallic ILs, and neutral ILs, that, from among them, functionalized ionic liquids (FILs) include a lot of ion exchange groups in their structure that improve and accelerate proton conduction through the polymeric membrane. In spite of positive features of using ILs, the leaching of ILs from the membranes during the operation of fuel cell is the main downside of these organic salts, which leads to reducing...

Sustainability, 2021

Elderberry fruits contain valuable components that are beneficial to human health. Owing to the h... more Elderberry fruits contain valuable components that are beneficial to human health. Owing to the high content of anthocyanins, elderberry extracts can be used as natural food colorants with health-promoting properties. Moreover, the development of new natural food dyes enables the reduction in the use of synthetic ones. Anthocyanins-rich elderberry dry extracts (EDE) were prepared from the same batch of frozen fruits applying water extraction, followed by membrane separation (batch B1) or purification by column chromatography (batch B2) and then spray-dried. Subsequently, the content of anthocyanins, flavonols, and polyphenols was determined. The extract obtained with the application of column chromatography (B2) contained 33% anthocyanins, which is more than typical market standards, whereas the extract B1 contained 14% anthocyanins. The color properties of both extracts were also determined. Since water was used as an extractant, the extracts are well soluble in water and can there...

Materials, 2021

A highly effective method was developed to functionalize ceramic supports (Al2O3 powders and memb... more A highly effective method was developed to functionalize ceramic supports (Al2O3 powders and membranes) using newly synthesized spacer molecules. The functionalized materials were subsequently utilized for Candida antarctica lipase B enzyme immobilization. The objective is to systematically evaluate the impact of various spacer molecules grafted onto the alumina materials will affect both the immobilization of the enzymes and specific material surface properties, critical to enzymatic reactors performance. The enzyme loading was significantly improved for the supports modified with shorter spacer molecules, which possessed higher grafting effectiveness on the order of 90%. The specific enzyme activity was found to be much higher for samples functionalized with longer modifiers yielding excellent enantioselectivity >97%. However, the enantiomeric ratio of the immobilized lipase was slightly lower in the case of shorter spacer molecules.

Doklady of the National Academy of Sciences of Belarus, 2021

Composite membranes for pervaporation were prepared by forming a selective layer based on cross-l... more 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...

Materials, 2020

Pervaporation is a membrane technique used to separate azeotropic and close boiling solvents. Het... more Pervaporation is a membrane technique used to separate azeotropic and close boiling solvents. Heterogenous PVA composite membranes with NaY zeolite supported on polyamide-6 were fabricated and utilized in organic–organic pervaporation. The efficiency of prepared membranes was evaluated in the separation of ethanol/ethyl tert-butyl ether (EtOH/ETBE) using separation factor (β) and the thickness normalized pervaporation separation index (PSIN). Implementation of the fringe projection phase-shifting method allowed to the determined contact angle corrected by roughness. The influence of the presence of water traces in the feed on the overall separation efficiency was also discussed using the enrichment factor for water (EFwater). The incorporation of NaY into PVA matrix increases surface roughness and hydrophilicity of the composite membrane. It was found that membranes selectively transport ethanol from the binary EtOH/ETBE mixture. The values of β (2.3) and PSIN (288 μm g m−2 h−1) for...

Polymers, 2020

A new type of hybrid polymeric-based film containing 1-(1,3-diethoxy-1,3-dioxopropan-2-ylo)-3-met... more A new type of hybrid polymeric-based film containing 1-(1,3-diethoxy-1,3-dioxopropan-2-ylo)-3-methylimidazolium bromide (RIL1_Br) and 1-(2-etoxy-2-oxoethyl)-3-methylimidazolium bromide (RIL2_Br) reactive ionic liquids was elaborated. Poly(vinyl alcohol) (PVA)-based films with 9–33 wt % of RILs were subsequently characterized using Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA) and TGA-FTIR. PVA-RIL films were also studied in tensile tests, contact angle and sorption measurements. RIL incorporation enhanced thermal and mechanical stability of PVA membranes due to the hydrogen bonds between RILs and polymer chains. Membrane swelling behavior in water (H2O), ethanol (EtOH), and propan-2-ol (IPA) and the kinetics of water sorption process revealed that PVA-RILs membranes possess the highest affinity towards water. It was pointed out that both the RIL...

Biomolecules, 2020

This short review analyzed the recent trend towards, progresses towards the preparation of chemic... more This short review analyzed the recent trend towards, progresses towards the preparation of chemicals of, and value-added biomaterials from marine macroalgae resources, especially green seaweeds and their derived ulvan polysaccharides for various applications. In recent years, ulvan both in pristine and modified forms has gained a large amount of attention for its effective utilization in various areas due to its unique physiochemical properties, lack of exploration, and higher green seaweed production. The pristine form of ulvan (sulfated polysaccharides) is used as a bio-component; food ingredient; or a raw material for the production of numerous chemicals such as fuels, cosmetics, and pharmaceuticals, whereas its modified form is used in the sector of composites, membranes, and scaffolds, among others, because of its physicochemical properties. This review highlights the utilization of green seaweed and its derived ulvan polysaccharides for the preparation of numerous chemicals (e...

Separation and Purification Technology, 2020

The PVDF membrane modification was performed utilizing the graphitic carbon nitride (g-C 3 N 4) i... more The PVDF membrane modification was performed utilizing the graphitic carbon nitride (g-C 3 N 4) in order to generate photocatalytic properties under visible light irradiation. Graphitic carbon nitride was synthesized via heating of melamine. Commercial PVDF ultrafiltration membranes with cutoff of 150 kDa were activated with a carbonate buffer and g-C 3 N 4 was subsequently attached by terminal amino groups. The structural and morphological properties of g-C 3 N 4 and membrane materials have been characterized using TEM, SEM-EDX, FTIR and EDX analysis. The adsorption of Rhodamine B and Rhodamine 6G on modified membranes and their subsequent degradation of dyes were studied. Membranes with immobilized g-C 3 N 4 possessed 10 times higher adsorption rate of Rhodamine 6G compared to Rhodamine B. The highest photocatalytic activity of modified membranes has been observed in alkaline media. Using isopropanol, tert-butylhydroquinone, potassium iodine and Cr(VI) as % OH, % O 2 − , h + and ē scavengers, it has been shown that the generated holes have been responsible for dyes degradation in acidic media and superoxide radicals in alkaline media, and both of them at neutral conditions. The transport through PVDF-g-C 3 N 4 membranes have been characterized by the volumetric flux of 320-350 L/(m 2 •h) during the ultrafiltration of dyes. Rejection of Rhodamine B and Rhodamine 6G was of 96 and 94%, respectively. The yield of dyes decomposition was about 80% and 85% for Rhodamine B and Rhodamine 6G, correspondingly, within the range of dye concentration from 5 to 50 mg/L. PVDF-g-C 3 N 4 membranes were characterized with high stability and reusability in process of dyes ultrafiltration in the crossflow mode. The loss of membrane activity after 5 cycles of ultrafiltration (total duration equal to 50 h) was approximately 15%.

Journal of Membrane Science, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Polymers, 2018

Pervaporation is a membrane-separation technique which uses polymeric and/or ceramic membranes. I... more Pervaporation is a membrane-separation technique which uses polymeric and/or ceramic membranes. In the case of pervaporation processes applied to dehydration, the membrane should transport water molecules preferentially. Reactive ionic liquid (RIL) (3-(1,3-diethoxy-1,3-dioxopropan-2-yl)-1-methyl-1H-imidazol-3-ium) was used to prepare novel dense cellulose acetate propionate (CAP) based membranes, applying the phase-inversion method. The designed polymer-ionic liquid system contained ionic liquid partially linked to the polymeric structure via the transesterification reaction. The various physicochemical, mechanical, equilibrium and transport properties of CAP-RIL membranes were determined and compared with the properties of CAP membranes modified with plasticizers, i.e., tributyl citrate (TBC) and acetyl tributyl citrate (ATBC). Thermogravimetric analysis (TGA) testified that CAP-RIL membranes as well as CAP membranes modified with TBC and ATBC are thermally stable up to at least 120 • C. Tensile tests of the membranes revealed improved mechanical properties reflected by reduced brittleness and increased elongation at break achieved for CAP-RIL membranes in contrast to pristine CAP membranes. RIL plasticizes the CAP matrix, and CAP-RIL membranes possess preferable mechanical properties in comparison to membranes with other plasticizers investigated. The incorporation of RIL into CAP membranes tuned the surface properties of the membranes, enhancing their hydrophilic character. Moreover, the addition of RIL into CAP resulted in an excellent improvement of the separation factor, in comparison to pristine CAP membranes, in pervaporation dehydration of propan-2-ol. The separation factor β increased from ca. 10 for pristine CAP membrane to ca. 380 for CAP-16.7-RIL membranes contacting an azeotropic composition of water-propan-2-ol mixture (i.e., 12 wt % water).

Materials (Basel, Switzerland), Jan 7, 2018

Advanced ceramic materials with a well-defined nano-architecture of their surfaces were formed by... more Advanced ceramic materials with a well-defined nano-architecture of their surfaces were formed by applying a two-step procedure. Firstly, a primary amine was docked on the ordered nanotubular ceramic surface via a silanization process. Subsequently, single-wall carbon nanotubes (SWCNTs) were covalently grafted onto the surface via an amide building block. Physicochemical (e.g., hydrophobicity, and surface free energy (SFE)), mechanical, and tribological properties of the developed membranes were improved significantly. The design, preparation, and extended characterization of the developed membranes are presented. Tools such as high-resolution transmission electron microscopy (HR-TEM), single-area electron diffraction (SAED) analysis, microscopy, tribology, nano-indentation, and Raman spectroscopy, among other techniques, were utilized in the characterization of the developed membranes. As an effect of hydrophobization, the contact angles (CAs) changed from 38° to 110° and f...

Applied Sciences, 2017

Hydrophilic ceramic membranes (tubular and planar) made of TiO 2 and Al 2 O 3 were efficiently mo... more Hydrophilic ceramic membranes (tubular and planar) made of TiO 2 and Al 2 O 3 were efficiently modified with non-fluorinated hydrophobic grafting molecules. As a result of condensation reaction between hydroxyl groups on the membrane and reactive groups of modifiers, the hydrophobic surfaces were obtained. Ceramic materials were chemically modified using three various non-fluorinated grafting agents. In the present work, the influence of grafting time and type of grafting molecule on the modification efficiency was evaluated. The changes of physicochemical properties of obtained hydrophobic surfaces were determined by measuring the contact angle (CA), roughness (RMS), and surface free energy (SFE). The modified surfaces were characterized by contact angle in the range of 111-132 •. Moreover, hydrophobic tubular membranes were utilized in air-gap membrane distillation to desalination of sodium chloride aqueous solutions. The observed permeate fluxes were in the range of 0.7-4.8 kg•m −2 •h −1 for tests with pure water. The values of permeate fluxes for membranes in contact with NaCl solutions were smaller, within the range of 0.4-2.8 kg•m −2 •h −1. The retention of NaCl in AGMD process using hydrophobized ceramic membranes was close to unity for all investigated membranes.

Journal of Membrane Science, 2016

Two ion-exchange membranes possessing perfluorinated backbone and sulfonic groups (i.e. Nafion s ... more Two ion-exchange membranes possessing perfluorinated backbone and sulfonic groups (i.e. Nafion s 120 and IonClad™ R4010) with lithium(I) counter-ions were investigated. The interactions between solvents of different polarity and the ion-exchange membranes with various morphologies were taken into account in order to better understand solvation and dissociation phenomena of the ion-pairs. Pervaporation of polar (i.e. water, methanol)-nonpolar (i.e. methyl acetate, dimethyl carbonate) liquid mixtures was carried out. It was revealed that the increase of the polar component concentration above 2 wt% in the feed mixture leads to dissociation of ion-pairs in Nafion membrane, which is reflected by the rapid increase of the polar component partial flux. In the case of IonClad membrane the dissociation of the ion-pairs during pervaporation was observed only when water was a polar feed component. The dissociation of ion-pairs was also evidenced in infrared study by observing the shift of symmetric stretching vibrations (ν s) bands of sulfonic groups to the lower wavenumbers, compared to the membrane in the dry state. The symmetric stretching vibrations (ν s) bands of the dry Nafion membrane and membrane solvated with water and methanol were equal to 1071 cm À 1 , 1058 cm À 1 , and 1054 cm À 1 , respectively. In the case of IonClad membrane the symmetric stretching vibration (ν s) bands changed in contact with water from 1047 cm À 1 (dry membrane) to 1037 cm À 1. The dissociation of the ion-pairs did not occur in IonClad membrane equilibrated with methanol, which is also consistent with the result obtained during pervaporation.

ACS Applied Materials & Interfaces, 2016

The combination of microscopic (atomic force microscopy and scanning electron microscopy) and gon... more The combination of microscopic (atomic force microscopy and scanning electron microscopy) and goniometric (static and dynamic measurements) techniques, and surface characterization (surface free energy determination, critical surface tension, liquid entry pressure, hydraulic permeability) was implemented to discuss the influence of perfluoroalkylsilanes structure and grafting time on the physicochemistry of the created hydrophobic surfaces on the titania ceramic membranes of 5 kD and 300 kD. The impact of molecular structure of perfluoroalkylsilanes modifiers (possessing from 6 to 12 carbon atoms in the fluorinated part of the alkyl chain) and the time of the functionalization process in the range of 5 to 35 h was studied. Based on the scanning electron microscopy with energy-dispersive X-ray spectroscopy, it was found that the localization of grafting molecules depends on the membrane pore size (5kD or 300kD). In the case of 5kD titania membranes, modifiers are attached mainly on the surface and only partially inside the membrane pores, whereas, for 300kD membranes, the perfluoroalkylsilanes molecules are present within the whole porous structure of the membranes. The application of 4 various types of PFAS molecules enabled for interesting observations and remarks. It was explained how to obtain ceramic membrane surfaces with controlled material (contact angle, roughness, contact angle hysteresis) and separation properties. Highly hydrophobic surfaces with low values of contact angle hysteresis and low roughness were obtained. These surfaces possessed also low values of critical surface tension, which means that surfaces are highly resistant to wetting. This finding is crucial in membrane applicability in separation processes. The obtained and characterized hydrophobic membranes were subsequently applied in air-gap membrane distillation processes. All membranes were very efficient in MD processes, showing good transport and selective properties (∼99% of NaCl salt rejection). Depending on the membrane pore size and used modifiers, the permeate flux was in the range of 0.5-4.5 kg·m(-2)·h(-1) and 0.3-4.2 kg·m(-2)·h(-1) for 5 kD and 300 kD membranes, respectively.

Ionics, 2015

The work is devoted to a computational study of three types of cationic polymeric membranes in Li... more The work is devoted to a computational study of three types of cationic polymeric membranes in Li +-ionic form, in water and methanol environments, at various solvation levels. The studied membranes Nafion, IonClad, and M3 possess the perfluorinated backbone; however, various side chains were terminated with the functional groups of distinctly different ionic strength. The paper discusses the structural features of the membrane-solvent clusters as well as an influence of the side chain nature on the dissociation of the functional groups and the binding energy of the solvent molecules. Additionally, the paper compares the obtained results for Li +-Nafion membrane in water with the results published earlier for H + and Na + forms.

Food and Bioprocess Technology, 2015

Hydrophobic polymeric membranes (PP, PTFE, and PVDF) were efficiently applied in juice concentrat... more Hydrophobic polymeric membranes (PP, PTFE, and PVDF) were efficiently applied in juice concentration by osmotic membrane distillation process at room temperature. The properties of applied membranes were characterized by the value of static contact angle, hysteresis of contact angle, surface free energy, roughness, mean flow pore size, maximum pore size or bubble point, and the pore size distribution before and after their utilization in osmotic membrane distillation (OMD). Furthermore, the mechanical strength of the membranes was evaluated using the Mullen burst technique and characterization of fouling behavior was done. The impact of stripping solutions, characterized by different water activities (NaCl and CaCl 2), type of membrane materials, and membrane morphology, on the transport properties in a dehydration process was evaluated. Apple and beet juices with a high level of antioxidants were chosen. The quality of juices has been assessed by determination of total polyphenols and antioxidant activity. In the dehydration process, the most efficient were 0.45-μm PTFE and 0.45-μm PVDF membranes (24 % improvement). No loss of polyphenol content or reduction of antioxidant activity was observed after the juice dehydration.