scholarly journals An Analytical Solution to the Problem of Hydrogen Isotope Passage through Composite Membranes Made from 2D Materials

Mathematics ◽  
2021 ◽  
Vol 9 (19) ◽  
pp. 2353
Author(s):  
Alexey Mikhailovich Bubenchikov ◽  
Mikhail Alekseevich Bubenchikov ◽  
Anna Sergeevna Chelnokova ◽  
Soninbayar Jambaa

An analytical solution to the problem of wave transport of matter through composite hyper-fine barriers is constructed. It is shown that, for a composite membrane consisting of two identical ultra-thin layers, there are always distances between the layers at which the resonant passage of one of the components is realized. Resonance makes it possible to separate de Broiler waves of particles with the same properties, which differ only in masses. Broad bands of hyper-selective separation of a hydrogen isotope mixture are found at the temperature of 40 K.

2019 ◽  
Vol 7 (45) ◽  
pp. 25802-25807 ◽  
Author(s):  
Priyanka Manchanda ◽  
Stefan Chisca ◽  
Lakshmeesha Upadhyaya ◽  
Valentina-Elena Musteata ◽  
Mark Carrington ◽  
...  

Thin layers of a covalent organic framework (COF) have been synthesized on a flexible polymeric support using a new diffusion-induction method under ambient conditions in reaction times as short as 3 hours.


Author(s):  
Tzyy-Lung Leon Yu ◽  
Shih-Hao Liu ◽  
Hsiu-Li Lin ◽  
Po-Hao Su

The PBI (poly(benzimidazole)) nano-fiber thin film with thickness of 18–30 μm is prepared by electro-spinning from a 20 wt% PBI/DMAc (N, N′-dimethyl acetamide) solution. The PBI nano-fiber thin film is then treated with a glutaraldehyde liquid for 24h at room temperature to proceed chemical crosslink reaction. The crosslink PBI nano-fiber thin film is then immersed in Nafion solutions to prepare Nafion/PBI nano-fiber composite membranes (thickness 22–34 μm). The morphology of the composite membranes is observed using a scanning electron microscope (SEM). The mechanical properties, conductivity, and unit fuel cell performance of membrane electrode assembly (MEA) of the composite membrane are investigated and compared with those of Nafion-212 membrane (thickness ∼50 μm) and Nafion/porous PTFE (poly(tetrafluoro ethylene)) composite membrane (thickness ∼22 μm). We show the present composite membrane has a similar fuel cell performance to Nafion/PTFE and a better fuel cell performance than Du Pont Nafion-212.


2021 ◽  
Author(s):  
Gandhimathi Sivasubramanian ◽  
Senthil Andavan Gurusamy Thangavelu ◽  
Berlina Maria Mahimai ◽  
Krishnan Hariharasubramanian ◽  
PARADESI DEIVANAYAGAM

Abstract Advanced polymer composite membranes were prepared from a linear sulfonated poly(ether ether ketone) (SPEEK) with bismuth cobalt zinc oxide [BCZO, (Bi2O3)0.07(CoO)0.03(ZnO)0.90] nanopowder as an inorganic additive for the application of H2-O2 fuel cell. Morphology data tend to provide evidences for the incorporation of BCZO into SPEEK polymer. Indeed, composite membrane loaded with 7.5 wt.% of BCZO was identified to uptake maximum water, while the pristine SPEEK membrane occurred to retain only 24.0 %. As such SPEEK matrix loaded with 7.5 wt.% of BCZO was found to exhibit the maximum proton conductivity of 0.030 S cm-1, whereas the pristine membrane was restricted to 0.021 S cm-1. Evidently, TGA profile of the composite membrane was measured to exhibit sufficient thermal stability to employ as electrolyte in fuel cell. The membrane electrode assembly of pristine SPEEK and SP-BCZO-7.5 wt.% membranes were fabricated and studied for their electrochemical performance. Indeed, the characteristics of newly developed composite membranes led to possess incredible feature towards fuel cell applications.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Baturalp Yalcinkaya ◽  
Fatma Yalcinkaya ◽  
Jiri Chaloupek

The aim of the study was to prepare a thin film nanofibrous composite membrane utilized for nanofiltration technologies. The composite membrane consists of a three-layer system including a nonwoven part as the supporting material, a nanofibrous scaffold as the porous surface, and an active layer. The nonwoven part and the nanofibrous scaffold were laminated together to improve the mechanical properties of the complete membrane. Active layer formations were done successfully via interfacial polymerization. A filtration test was carried out using solutions of MgSO4, NaCl, Na2SO4, CaCl2, and real seawater using the dead-end filtration method. The results indicated that the piperazine-based membrane exhibited higher rejection of divalent salt ions (>98%) with high flux. In addition, them-phenylenediamine-based membrane exhibited higher rejection of divalent and monovalent salt ions (>98% divalent and >96% monovalent) with reasonable flux. The desalination of real seawater results showed that thin film nanofibrous composite membranes were able to retain 98% of salt ions from highly saline seawater without showing any fouling. The electrospun nanofibrous materials proved to be an alternative functional supporting material instead of the polymeric phase-inverted support layer in liquid filtration.


2005 ◽  
Vol 284-286 ◽  
pp. 811-814 ◽  
Author(s):  
Toshiki Itoh ◽  
Seiji Ban ◽  
T. Watanabe ◽  
Shozo Tsuruta ◽  
Takahiro Kawai ◽  
...  

It is well known that bone morphogenetic protein (BMP) induces bone formation and requires for carriers. Poly-lactic acid / poly-glycolic acid (PLGA) is frequently used as the carriers of BMP. We developed a biodegradable composite PLGA membrane, which was containing oriented needle-like apatite with BMP. The composite membranes were implanted into the thigh muscle pouch of 3-week-old-mice. At 3 weeks after implantation, the implanted area was observed by optical microscopy. The composite membrane containing oriented needle-like apatite with BMP induced new bone formation. It seems that this composite membrane might be a scaffold of BMP and promoting the healing of bone defects.


Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 166 ◽  
Author(s):  
Haiquan Mao ◽  
Chun Wei ◽  
Yongyang Gong ◽  
Shiqi Wang ◽  
Wenwen Ding

Environmentally benign and biodegradable chitosan (CS) membranes have disadvantages such as low mechanical strength, high brittleness, poor heat resistance and poor water resistance, which limit their applications. In this paper, home-made cellulose nanocrystals (CNC) were added to CS to prepare CNC/CS composite membranes through mechanical mixing and solution casting approaches. The effects of CNC dispersion patterns and CNC contents on the properties of composite membranes were studied. The analysis of the surface and cross-section morphology of the membranes showed that the dispersion performance of the composite membrane was better in the case that CNC was dissolved in an acetic acid solution and then mixed with chitosan by a homogenizer (Method 2). CNC had a great length-diameter ratio and CNC intensely interacted with CS. The mechanical properties of the composite membrane prepared with Method 2 were better. With a CNC content of 3%, the tensile strength of the composite membrane reached 43.0 MPa, 13.2% higher than that of the CNC-free membrane. The elongation at break was 41.6%, 56.4% higher than that of the CNC-free membrane. Thermogravimetric, contact angle and swelling analysis results showed that the addition of CNC could improve the heat and water resistance of the chitosan membrane.


2018 ◽  
Vol 6 (47) ◽  
pp. 24641-24650 ◽  
Author(s):  
Lei Zhang ◽  
Liang Cheng ◽  
Haochen Wu ◽  
Tomohisa Yoshioka ◽  
Hideto Matsuyama

A robust and anti-oil-fouling aliphatic polyketone composite membrane for sustainable and efficient filtration of oil-in-water emulsions.


2015 ◽  
Vol 1123 ◽  
pp. 182-186 ◽  
Author(s):  
Mumpuni Asih Pratiwi ◽  
Ronny Windu Sudrajat ◽  
Sri Sutanti ◽  
Heru Susanto

In the last decade pervaporation membrane has become an antractive dehydration processs for azeotropic ethanol-water mixture. In this paper, chitosan-alginate/polyethersulfone (PES) composite membranes were prepared (by coating method) characterized as pervaporation membranes. The composite membranes were then examined to purify ethanol-water mixture. The characterization included degree of swelling both in water and ethanol, permeability measurement, surface morphology (by SEM) and surface chemistry (by FTIR). The results show that the increase in concentration of coating solution increases the degree of swelling in the water on the one hand, whereas the permeability and the degree of swelling in the ethanol decreases on the other hand. The highest permeability was obtained for the composite membrane prepared from a coating solution concentration of 1% with the ratio of chitosan to alginate was 0,33. The surface chemistry shows that the increase in concentration of chitosan - alginate solution increases the intensity of a specific wave number of C-O and C-N groups. Surface morphology indicates that the PES membrane surface is clearly covered by chitosan - alginate mixture. Performance examination demonstrates that the composite membrane prepared by 3% a coating solution (with the ratio of chitosan to alginate 3) can increase the bioethanol concentration from 95.5% to 99.6%.


RSC Advances ◽  
2016 ◽  
Vol 6 (62) ◽  
pp. 56986-56999 ◽  
Author(s):  
J. L. Reyes-Rodriguez ◽  
O. Solorza-Feria ◽  
A. García-Bernabé ◽  
E. Giménez ◽  
O. Sahuquillo ◽  
...  

Nanofiber mats of SPEEK70wt%–PVB30wt% (polyvinyl butyral)-based composite membranes were prepared by varying the electrospinning time in order to obtain mats with different thicknesses.


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