scholarly journals Spectroscopic and Transport Behavior of HAB-6FDA Thermally Rearranged (TR) Nanocomposite Membranes

Author(s):  
Harsh Patel ◽  
NAVEEN KUMAR ACHARYA

Abstract Nanocomposite membranes are a class of innovative filtering materials made up of nanofillers embedded in a polymeric or inorganic oxide matrix that functionalized for the membrane. Thermally rearranged (TR) polymers are found to have a good blending of selectivity and permeability. Chemical iridization is a process for used to make HAB-6FDA polyimide from 3,3 dihydroxy-4,4 diamino-biphenyl (HAB) & 2,2-bis-(3,4-dicarboxyphenyl) hexafluoro propane dianhydride (6FDA). The sample is first changed from a pure polymer membrane to a silica nanofiller doped polymer layer and explain thermally rearrangement for gas permeability in polymer nanocomposite layers and its relationship with kinetic diameter of different gases. The selectivity is decreases as the permeability increases that shows on a trade-off relationship between permeability & selectivity. The CO2 permeability of the HAB-6FDA TR polymers is greater than that of other classes of polymers by equal free volume and indicating that these TR polymers have free volume distribution that supports high permeability. Thermally rearranged polymer nanocomposite exhibits higher gas permeability than that of silica doped and pure polymer. The selectivity for H2/N2 and H2/CO2 gas pairs exceeds towards Robeson's upper bound limit and in case of H2/CH4 gas pair this limit were crossed the Robeson’s upper bond limit. UV spectroscopy shows the change in transmission at higher wavelengths, while XRD show the reduction in FWHM with thermal treatment temperature. Polymer nanocomposite can be utilized to obtain high purity hydrogen gas for refinery and petrochemical applications.

MRS Advances ◽  
2016 ◽  
Vol 1 (42) ◽  
pp. 2873-2880
Author(s):  
Anshu Sharma ◽  
S. P. Nehra ◽  
Y. K. Vijay ◽  
I. P. Jain

ABSTRACTThe goal of this work is to study the properties of magnetically aligned CNT/PC nanocomposites towards the development of hydrogen gas separation membranes. A fraction (0.1 weight %) of synthesized carbon nanotubes (CNTs) have been dispersed homogeneously throughout polycarbonate (PC) matrix by ultrasonication. The alignment of CNT in PC matrix has been accomplished by applying an external magnetic field of 1200 Gauss. These nanocomposites have been studied by gas permeation using H2, N2and Co2electrical and dielectric constant measurements. Experimental results of gas permeability measurements exhibit here that H2is more selective than N2and Co2in magnetically aligned nanocomposite membranes which can be used as good hydrogen separating media. I-V characteristics show the electron hopping like behavior and dielectric constant shows the enhancement in permittivity of these nanocomposites.


Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 139
Author(s):  
Oluranti Agboola ◽  
Ojo Sunday Isaac Fayomi ◽  
Ayoola Ayodeji ◽  
Augustine Omoniyi Ayeni ◽  
Edith E. Alagbe ◽  
...  

Globally, environmental challenges have been recognised as a matter of concern. Among these challenges are the reduced availability and quality of drinking water, and greenhouse gases that give rise to change in climate by entrapping heat, which result in respirational illness from smog and air pollution. Globally, the rate of demand for the use of freshwater has outgrown the rate of population increase; as the rapid growth in town and cities place a huge pressure on neighbouring water resources. Besides, the rapid growth in anthropogenic activities, such as the generation of energy and its conveyance, release carbon dioxide and other greenhouse gases, warming the planet. Polymer nanocomposite has played a significant role in finding solutions to current environmental problems. It has found interest due to its high potential for the reduction of gas emission, and elimination of pollutants, heavy metals, dyes, and oil in wastewater. The revolution of integrating developed novel nanomaterials such as nanoparticles, carbon nanotubes, nanofibers and activated carbon, in polymers, have instigated revitalizing and favourable inventive nanotechnologies for the treatment of wastewater and gas separation. This review discusses the effective employment of polymer nanocomposites for environmental utilizations. Polymer nanocomposite membranes for wastewater treatment and gas separation were reviewed together with their mechanisms. The use of polymer nanocomposites as an adsorbent for toxic metals ions removal and an adsorbent for dye removal were also discussed, together with the mechanism of the adsorption process. Patents in the utilization of innovative polymeric nanocomposite membranes for environmental utilizations were discussed.


2002 ◽  
Vol 87 (3) ◽  
pp. 497-501 ◽  
Author(s):  
Jing Jing Bi ◽  
C. L. Wang ◽  
Y. Kobayashi ◽  
K. Ogasawara ◽  
A. Yamasaki

2009 ◽  
Vol 34 (9) ◽  
pp. 3977-3982 ◽  
Author(s):  
Anshu Sharma ◽  
Sumit Kumar ◽  
Balram Tripathi ◽  
M. Singh ◽  
Y.K. Vijay

2021 ◽  
pp. 131181
Author(s):  
Samy Yousef ◽  
Justas Eimontas ◽  
Nerijus Striūgas ◽  
Alaa Mohamed ◽  
Mohammed AliAbdelnaby

1999 ◽  
Vol 32 (4) ◽  
pp. 1147-1151 ◽  
Author(s):  
K. Süvegh ◽  
M. Klapper ◽  
A. Domján ◽  
S. Mullins ◽  
W. Wunderlich ◽  
...  

Author(s):  
A.C. Fox ◽  
T.W. Clyne

Abstract A simple test procedure, based on steady state flow through a membrane, has been developed for measurement of the gas permeability of specimens over a range of temperature. The reliability of this equipment has been verified by testing solid disks containing single perforations and comparing the measured flow rates with those expected on the basis of laminar flow. Coatings of yttria-stabilised zirconia have been produced by plasma spraying in vacuum and in air. The specific permeability of these coatings has been measured at temperatures ranging up to 600°C, using hydrogen gas. It has been found that permeability is increased for coatings produced with longer stand-off distances and at higher pressures. Porosity levels have been measured using densitometry and microstructural features have been examined using SEM. A model has been developed for prediction of the permeability from such microstructural features, based on percolation theory. Agreement between predicted and measured permeabilities is good, although it is clear that more comprehensive data are needed in order to validate the model systematically.


2018 ◽  
Vol 8 (7) ◽  
pp. 1181 ◽  
Author(s):  
Svetlana Kononova ◽  
Galina Gubanova ◽  
Eleonora Korytkova ◽  
Denis Sapegin ◽  
Katerina Setnickova ◽  
...  

Based on the results of research works reflected in the scientific literature, the main examples, methods and approaches to the development of polymer inorganic nanocomposite materials for target membranes are considered. The focus is on membranes for critical technologies with improved mechanical, thermal properties that have the necessary capabilities to solve the problems of a selective pervaporation. For the purpose of directional changes in the parameters of membranes, effects on their properties of the type, amount and conditions of nanoparticle incorporation into the polymer matrix were analyzed. An influence of nanoparticles on the structural and morphological characteristics of the nanocomposite film is considered, as well as possibilities of forming transport channels for separated liquids are analyzed. Particular attention is paid to a correlation of nanocomposite structure-transport properties of membranes, whose separation characteristics are usually considered within the framework of the diffusion-sorption mechanism.


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