scholarly journals Novel Poly(ionic liquid) Augmented Membranes for Unconventional Aqueous Phase Applications in Fractionation of Dyes and Sugar

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2366
Author(s):  
Sandrina DePaz ◽  
Arijit Sengupta ◽  
Yu-Hsuan Chiao ◽  
Sumith Wickramasinghe

Poly(ionic) liquid (PIL) augmented membranes were fabricated through self-polymerization of 2-vinyl pyridine and 4-vinyl pyridine followed by dopamine triggered polymerization and bridging with inert polyamide support. The resulting membranes acquired a positive surface charge with a high degree of hydrophilicity. Fourier transformed Infra-red (FTIR) and Energy dispersive X-ray (EDX) spectroscopic investigation revealed the successful augmentation of PIL surface layer, whereas surface morphology was investigated through scanning electron microscopy (SEM) imaging. This manuscript demonstrates pi electron-induced separation of dyes with the trend in permeability: Coomassie Brilliant Blue G (CBBHG)> Remazol Brilliant Blue R (RBBR)>Eichrome Black T (EBT)> Congo Red (CR). CBBG exhibited extended conjugation over large aromatic domain. RBBR and EBT were associated withtheelectron-donating -NH2 group and electron-withdrawing -NO2 group, respectively, hence pi electron density on aromatic ring varied. The steric repulsion between two pairs of ortho hydrogens (Hs) in biphenyl moieties of CR resulted in deviation of planarity and hence aromaticity leading to the lowest permeability. The sugar fractionation followed the trend: Galactose > Mannose > Fructose > Glucose > Xylose. More hydroxyl (-OH) groups in sugars and their conformational alignment in the same direction, exhibited more lone pair of electrons leading to more interaction with PIL and hence better permeability. Pentose showed poorer permeation than hexose, whereas aldose showed better permeation than ketose.

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 441
Author(s):  
Abdelrahman O. Ezzat ◽  
Ahmed M. Tawfeek ◽  
Jothi Ramalingam Rajabathar ◽  
Hamad A. Al-Lohedan

In this work, new crosslinked pyridinium poly ionic liquid and its magnetite hybrid structured composite were prepared and applied to remove the toxic dye Coomassie Brilliant Blue (CBB-R250) from aqueous solutions. In this respect, vinyl pyridine, maleic anhydride, and dibromo nonane were used to prepare crosslinked quaternized vinyl pyridinium/maleic anhydride ionic liquid (CQVP-MA). Furthermore, a linear copolymer was prepared by the reaction of vinyl pyridine with bromo nonane followed by its copolymerization with maleic anhydride in order to use it as a capping agent for magnetite nanoparticles. The monodisperse MNPs were incorporated into the crosslinked PIL (CQVP-MA) by ultrasonication to prepare CQVP-MA/Fe3O4 composite to facilitate its recovery using an external magnetic field and enhance its adsorption capacity. The chemical structures, thermal stabilities, zeta potential, particle size, EDS, and SEM of the prepared CQVP-MA and CQVP-MA/Fe3O4 were investigated. Adsorption kinetics, isotherms, and mechanisms of CB-R250 elimination from aqueous solutions using CQVP-MA and CQVP-MA/Fe3O4 were also studied, and the results revealed that the pseudo second-order kinetic model and the Langmuir isotherm model were the most suitable to describe the CBB adsorption from an aqueous solution. The adsorption capacities of CQVP-MA and CQVP-MA/Fe3O4 were found to be 1040 and 1198, respectively, which are more than those for previously reported material in the literature with reasonable stability for five cycles.


2017 ◽  
Vol 29 (6) ◽  
pp. 691-703 ◽  
Author(s):  
Sofia M Morozova ◽  
Alexander S Shaplov ◽  
Elena I Lozinskaya ◽  
Petr S Vlasov ◽  
Haritz Sardon ◽  
...  

The synthesis of cationic polyelectrolytes based on condensation-derived backbone is rarely performed due to the difficulty obtaining of the respective ionic monomers in high purity. Despite such an approach is favorable as it results in ionic polymers with well-defined chemical structure and ionic group distribution. In this work two efficient methods are presented for the synthesis of ionic diols in high purity, namely the technique with pyranyl protection of OH-groups and the direct quaternization of tertiary amine alcohols. Applying these methods five novel ionic diols bearing various cations, namely, 1,1-bis(2-hydroxyethyl)pyrrolidin-1-ium bromide, 4,4-bis(2-hydroxyethyl)morpholin-4-ium bromide, N, N-bis(2-hydroxyethyl)-N-methylethanammonium, 1,1′-(pentane-1,5-diyl)bis(1-(2-hydroxyethyl)pyrrolidin-1-ium) dibromide, and 3-(2-hydroxyethyl)-1-(5-(3-(3-hydroxypropyl)-1H-imidazol-3-ium-1-yl)pentyl)-1H-imidazol-3-ium dibromide, were synthesized in high purity and high yields. The tin(II) mediated solution polycondensation of ionic diols with commercial hexamethylene diisocyanate or 4,4′-methylenebis(cyclohexyl isocyanate) resulted in a series of ionic, high molecular weight ( Mw = 2.3 × 104 −8.0 × 104) polyurethanes (PUs). The influence of various reaction parameters including reaction temperature and time, catalyst concentration and solvent nature upon PUs molecular weight was investigated. After the exchange of bromide to (CF3SO2)2N- anion the obtained poly(ionic liquid)s exhibit high thermal stability with onset mass loss above 225°C and demonstrate glass transition temperatures in the wide range from −22°C to 76°C depending on the nature of ionic diol used. Ionic PUs present excellent solubility in most organic solvents and are capable to form tough, flexible films with tensile strength up to 29.7 MPa.


2019 ◽  
Author(s):  
Paul Pearce ◽  
Gaurav Assat ◽  
Antonella Iadecola ◽  
François Fauth ◽  
Rémi Dedryvère ◽  
...  

The recent discovery of anionic redox as a means to increase the energy density of transition metal oxide positive electrodes is now a well established approach in the Li-ion battery field. However, the science behind this new phenomenon pertaining to various Li-rich materials is still debated. Thus, it is of paramount importance to develop a robust set of analytical techniques to address this issue. Herein, we use a suite of synchrotron-based X-ray spectroscopies as well as diffraction techniques to thoroughly characterize the different redox processes taking place in a model Li-rich compound, the tridimentional hyperhoneycomb β-Li2IrO3. We clearly establish that the reversible removal of Li+ from this compound is associated to a previously described reductive coupling mechanism and the formation of the M-(O-O) and M-(O-O)* states. We further show that the respective contributions to these states determine the spectroscopic response for both Ir L3-edge X-ray absorption spectroscopy (XAS) and X-ray photoemissions spectroscopy (XPS). Although the high covalency and the robust tridimentional structure of this compound enable a high degree of reversibile delithiation, we found that pushing the limits of this charge compensation mechanism has significant effects on the local as well as average structure, leading to electrochemical instability over cycling and voltage decay. Overall, this work highlights the practical limits to which anionic redox can be exploited and sheds some light on the nature of the oxidized species formed in certain lithium-rich compounds.<br>


2019 ◽  
Author(s):  
Paul Pearce ◽  
Gaurav Assat ◽  
Antonella Iadecola ◽  
François Fauth ◽  
Rémi Dedryvère ◽  
...  

The recent discovery of anionic redox as a means to increase the energy density of transition metal oxide positive electrodes is now a well established approach in the Li-ion battery field. However, the science behind this new phenomenon pertaining to various Li-rich materials is still debated. Thus, it is of paramount importance to develop a robust set of analytical techniques to address this issue. Herein, we use a suite of synchrotron-based X-ray spectroscopies as well as diffraction techniques to thoroughly characterize the different redox processes taking place in a model Li-rich compound, the tridimentional hyperhoneycomb β-Li2IrO3. We clearly establish that the reversible removal of Li+ from this compound is associated to a previously described reductive coupling mechanism and the formation of the M-(O-O) and M-(O-O)* states. We further show that the respective contributions to these states determine the spectroscopic response for both Ir L3-edge X-ray absorption spectroscopy (XAS) and X-ray photoemissions spectroscopy (XPS). Although the high covalency and the robust tridimentional structure of this compound enable a high degree of reversibile delithiation, we found that pushing the limits of this charge compensation mechanism has significant effects on the local as well as average structure, leading to electrochemical instability over cycling and voltage decay. Overall, this work highlights the practical limits to which anionic redox can be exploited and sheds some light on the nature of the oxidized species formed in certain lithium-rich compounds.<br>


Author(s):  
Wenxin Wei ◽  
Guifeng Ma ◽  
Hongtao Wang ◽  
Jun Li

Objective: A new poly(ionic liquid)(PIL), poly(p-vinylbenzyltriphenylphosphine hexafluorophosphate) (P[VBTPP][PF6]), was synthesized by quaternization, anion exchange reaction, and free radical polymerization. Then a series of the PIL were synthesized at different conditions. Methods: The specific heat capacity, glass-transition temperature and melting temperature of the synthesized PILs were measured by differential scanning calorimeter. The thermal conductivities of the PILs were measured by the laser flash analysis method. Results: Results showed that, under optimized synthesis conditions, P[VBTPP][PF6] as the thermal insulator had a high glass-transition temperature of 210.1°C, high melting point of 421.6°C, and a low thermal conductivity of 0.0920 W m-1 K-1 at 40.0°C (it was 0.105 W m-1 K-1 even at 180.0°C). The foamed sample exhibited much low thermal conductivity λ=0.0340 W m-1 K-1 at room temperature, which was comparable to a commercial polyurethane thermal insulating material although the latter had a much lower density. Conclusion: In addition, mixing the P[VBTPP][PF6] sample into polypropylene could obviously increase the Oxygen Index, revealing its efficient flame resistance. Therefore, P[VBTPP][PF6] is a potential thermal insulating material.


2021 ◽  
Vol 23 (15) ◽  
pp. 9061-9064
Author(s):  
Ralph A. Wheeler ◽  
Emily E. Dalbey

Fitting X-ray structure factor lineshapes from experiment or simulation quantifies the nanoscale range of charge alternation in the title compound.


2021 ◽  
Vol 6 (15) ◽  
pp. 3795-3801
Author(s):  
Radostina Kalinova ◽  
Ivaylo Dimitrov ◽  
Christo Novakov ◽  
Svetlana Veleva ◽  
Antonia Stoyanova

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