scholarly journals Novel Membranes Based on Hydroxyethyl Cellulose/Sodium Alginate for Pervaporation Dehydration of Isopropanol

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 674
Author(s):  
Mariia Dmitrenko ◽  
Andrey Zolotarev ◽  
Vladislav Liamin ◽  
Anna Kuzminova ◽  
Anton Mazur ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
Membrane Surface ◽  
Physicochemical Characteristics ◽  
Hydroxyethyl Cellulose ◽  
Permeation Flux ◽  
Layer By Layer ◽  
Supported Membranes ◽  
Supported Membrane ◽  
Layer Deposition ◽  
Selection Of

Membrane methods, especially pervaporation, are quickly growing up. In line with that, effective membrane materials based on biopolymers are required for the industrially significant mixtures separation. To essentially improve membrane transport characteristics, the application of the surface or/and bulk modifications can be carried out. In the present study, novel dense and supported membranes based on hydroxyethyl cellulose (HEC)/sodium alginate (SA) were developed for pervaporation dehydration of isopropanol using several approaches: (1) the selection of the optimal ratio of polymers, (2) the introduction of fullerenol in blend polymer matrix, (3) the selection of the optimal cross-linking agent for the membranes, (4) the application of layer-by-layer deposition of polyelectrolytes on supported membrane surface (poly(sodium 4-styrenesulfonate) (PSS)/poly(allylamine hydrochloride) (PAH) and PSS/SA). Structural and physicochemical characteristics of the membranes were analyzed by different methods. A cross-linked supported membrane based on HEC/SA/fullerenol (5%) composite possessed the following transport characteristics in pervaporation dehydration of isopropanol (12–50 wt.% water): 0.42–1.72 kg/(m2h) permeation flux, and 77.8–99.99 wt.% water content in the permeate. The surface modification of this membrane with 5 bilayers of PSS/PAH and PSS/SA resulted in the increase of permeation flux up to 0.47–3.0 and 0.46–1.9 kg/(m2h), respectively, with lower selectivity.

Preparation and Morphology of CdZnS Thin Films

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940060
Author(s):  
S. I. Sadovnikov
Keyword(s):  
Thin Films ◽  
Text Structure ◽  
Layer By Layer ◽  
Space Group ◽  
Synthesis Conditions ◽  
Layer Deposition ◽  
Two Phases ◽  
The Relationship ◽  
Selection Of ◽  
Deposition Conditions

Thin films based on limited solid solutions of cadmium and zinc sulfides have been synthesized by a one-stage epitaxial layer-by-layer deposition from an ammonium-containing aqueous solution of cadmium and zinc chlorides and thiocarbamide on a glass substrate. The thickness control of sulfide layers was carried out by selection of reagent concentrations and the deposition conditions. The relationship between the synthesis conditions of CdxZn[Formula: see text]S thin films and the size of sulfide nanoparticles in these films is established. The films contain two phases: hexagonal (space group [Formula: see text]) phase with [Formula: see text] structure of wurtzite type and cubic (space group [Formula: see text]-[Formula: see text]) phase with [Formula: see text] structure of sphalerite type. It is shown that the CdxZn[Formula: see text]S film consists of separate [Formula: see text][Formula: see text]nm agglomerates which are a collection of smaller nanometer-sized particles. The dependence of the band gap of the synthesized films on their thickness is found.

scholarly journals Novel Mixed Matrix Sodium Alginate–Fullerenol Membranes: Development, Characterization, and Study in Pervaporation Dehydration of Isopropanol

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 864 ◽  
Author(s):  
Mariia Dmitrenko ◽  
Vladislav Liamin ◽  
Anna Kuzminova ◽  
Anton Mazur ◽  
Erkki Lahderanta ◽  
...  
Keyword(s):  
Transport Properties ◽  
Sodium Alginate ◽  
Physicochemical Characteristics ◽  
Wide Concentration Range ◽  
Supported Membranes ◽  
Mixed Matrix ◽  
Atomic Force ◽  
Separation Factors ◽  
Promising Application ◽  
Pervaporation Separation

Novel mixed matrix dense and supported membranes based on biopolymer sodium alginate (SA) modified by fullerenol were developed. Two kinds of SA–fullerenol membranes were investigated: untreated and cross-linked by immersing the dry membranes in 1.25 wt % calcium chloride (CaCl2) in water for 10 min. The structural and physicochemical characteristics features of the SA–fullerenol composite were investigated by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopic methods, scanning electron (SEM) and atomic force (AFM) microscopies, thermogravimetric analysis (TGA), and swelling experiments. Transport properties were evaluated in pervaporation dehydration of isopropanol in a wide concentration range. It was found that the developed supported cross-linked SA-5/PANCaCl2 membrane (modified by 5 wt % fullerenol) possessed the best transport properties (the highest permeation fluxes 0.64–2.9 kg/(m2 h) and separation factors 26–73,326) for the pervaporation separation of the water–isopropanol mixture in the wide concentration range (12–90 wt % water) at 22 °C and is suitable for the promising application in industry.

scholarly journals Modification Approaches to Enhance Dehydration Properties of Sodium Alginate-Based Pervaporation Membranes

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 255
Author(s):  
Mariia Dmitrenko ◽  
Vladislav Liamin ◽  
Anna Kuzminova ◽  
Erkki Lahderanta ◽  
Nikolay Solovyev ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
Fullerene Derivative ◽  
Regenerated Cellulose ◽  
Layer By Layer ◽  
Porous Substrate ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Selection Of

Transport characteristics of sodium alginate (SA) membranes cross-linked with CaCl2 and modified with fullerenol and fullerene derivative with L-arginine for pervaporation dehydration were improved applying various approaches, including the selection of a porous substrate for the creation of a thin selective SA-based layer, and the deposition of nano-sized polyelectrolyte (PEL) layers through the use of a layer-by-layer (Lbl) method. The impacts of commercial porous substrates made of polyacrylonitrile (PAN), regenerated cellulose, and aromatic polysulfone amide were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), standard porosimetry method, and water filtration. The effects of PEL combinations (such as poly(sodium 4-styrene sulfonate) (PSS)/SA, PSS/chitosan, PSS/polyacrylic acid, PSS/poly(allylamine hydrochloride)) and the number of PEL bilayers deposited with the Lbl technique on the properties of the SA and SA/fullerene derivative membranes were studied by SEM, AFM, and contact angle measurements. The best characteristics were exhibited by a cross-linked PAN-supported SA/fullerenol (5%) membrane with five PSS/SA bilayers: permeation flux of 0.68–1.38 kg/(m2h), 0.18–1.55 kg/(m2h), and 0.50–1.15 kg/(m2h), and over 99.7, 99.0, and 89.0 wt.% water in the permeate for the pervaporation dehydration of isopropanol (12–70 wt.% water), ethanol (4–70 wt.% water), and tetrahydrofuran (5.7–70 wt.% water), respectively. It was demonstrated that the mutual application of bulk and surface modifications essentially improved the membrane’s characteristics in pervaporation dehydration.

Immobilizing hydroxyapatite microparticles on poly(lactic acid) nonwoven scaffolds using layer-by-layer deposition

2016 ◽  
Vol 87 (16) ◽  
pp. 2028-2038 ◽  
Author(s):  
Anssar Houdali ◽  
Nemeshwaree Behary ◽  
Jean-Christophe Hornez ◽  
Philippe Vroman ◽  
Christine Campagne ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Sodium Alginate ◽  
Porous Scaffold ◽  
Average Pore Size ◽  
Fiber Surface ◽  
Bone Cell ◽  
Poly Lactic Acid ◽  
Layer By Layer ◽  
Average Pore ◽  
Layer Deposition

A composite porous scaffold for bone cell culture was fabricated by immobilizing HA (hydroxyapatite) (Ca10 (PO4)6 (OH)2) microparticles on PLA (poly(lactic acid)) nonwoven fibers using the layer-by-layer deposition technique. A nonwoven PLA of thickness 1 mm, with average pore size of 230 µm and a porosity of 94%, was used. The nonwoven was functionalized with aqueous 65% deacetylated chitosan followed by rinsing, and then a second padding with aqueous sodium alginate loaded with varying percentages of HA microparticles (0.01%, 0.1% and 0.2%), resulting in a composite porous nonwoven. Sodium alginate was revealed to be an efficient polymer for obtaining a stable dispersion of the HA microparticles in an aqueous medium. Atomic force microscopy and scanning electron microscopy images, zeta potential and wettability tests showed successfully the different surface modifications occurring at each step of surface functionalization. The chitosan coating cationized the PLA fiber surface, providing good adhesion of the HA-loaded anionic alginate coating. HA was almost homogeneously distributed at the PLA fiber surfaces with only a small reduction in the scaffold porosity, which reached 75%. The composite PLA/chitosan/alginate/HA nonwoven structures were tested as scaffold for adhesion and proliferation of rat pre-osteoblast MC3T3-E1 cells. The results showed that higher loading with HA improved the MC3T3 cell adhesion and proliferation after 3 and 6 days of culture.

Radical-triggered cross-linking for molecular layer deposition of SiAlCOH hybrid thin films

2021 ◽  
Author(s):  
Kristina Ashurbekova ◽  
Karina Ashurbekova ◽  
Iva Saric ◽  
Evgeny Modin ◽  
Mladen Petravic ◽  
...  
Keyword(s):  
Thin Film ◽  
Film Growth ◽  
Molecular Layer ◽  
Thin Film Growth ◽  
Cross Linking ◽  
Layer By Layer ◽  
Molecular Layer Deposition ◽  
Layer Deposition ◽  
Hybrid Thin Films ◽  
Enhanced Stability

We developed a thin film growth with a radical-initiated cross-linking of vinyl groups in a layer-by-layer manner via molecular layer deposition (MLD). The cross-linked film exhibited improved properties like 12% higher density and enhanced stability compared to the non-cross-linked film.

Layer-by-layer of graphene oxide-chitosan assembly on PVA membrane surface for the pervaporation separation of water-isopropanol mixtures

2021 ◽  
Vol 38 (2) ◽  
pp. 411-421
Author(s):  
Shivshankar Chaudhari ◽  
KieYong Cho ◽  
SoHyan Joo ◽  
ByeongYun An ◽  
SongEun Lee ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Membrane Surface ◽  
Layer By Layer ◽  
Pervaporation Separation
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