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Current challenges in rubber modeling: Filler flocculation kinetics and self-healing network properties
Published in Bertrand Huneau, Jean-Benoit Le Cam, Yann Marco, Erwan Verron, Constitutive Models for Rubber XI, 2019
Another approach from IPF Dresden allowed tailoring of the polymer properties of self-healing BIIR to a large extent (Suckow et al. 2016). New poly(ionic liquids) were synthesized by a two stage polymer analogous reaction. In the first stage, the reactive maleic anhydride groups of the starting polymer were converted with 1-(3-aminopropyl)-imidazole. The second stage comprises an alkylation reaction of the imidazole groups with various alkylbromides. With the degree of conversion, the number of reactive groups remaining in the polymer could be adjusted. The possibility to preserve reactive groups opens new applications of the poly(ionic liquid)s as reactive blend components. Another focus is directed to the nature of self-healing of ionically modified rubbers obtained by reaction of brominated poly(isobutylene-co-isoprene) rubber (BIIR) with various alkylimidazoles such as 1-methylimidazole, 1-butylimidazole, 1-hexylimidazole, 1-nonylimidazole, and 1-(6-chlorohexyl)-1H-imidazole (Suckow et al. 2018). Based on stress−strain and temperature dependent DMA measurements, a structural influence of the introduced ionic imidazolium moieties on the formation of ionic clusters and, as a consequence, on the mechanical strength and self-healing behavior of the samples could be evidenced. These results are fully supported by a molecular-level assessment of the network structure (cross-link and constraint density) and the dynamics of the ionic clusters using an advanced proton low-field NMR technique (Suckow et al. 2018).
Smart and Intelligent Packaging Based on Biodegradable Composites
Published in Arbind Prasad, Ashwani Kumar, Kishor Kumar, Biodegradable Composites for Packaging Applications, 2023
Theivasanthi Thirugnanasambandan
It is often difficult to print conductive silver ink on cellulose packaging. Hence, conductive ink is prepared by thermal reduction of silver acetate in ionic liquid, namely 1-methylimidazole. The reduction can also be performed by irradiating with UV light. This method can bring out conductivity across the cellulose foil (Samusjew et al., 2018). Silver nanoparticle conductive ink is printed on paper as electrodes. Paper (dielectric material) was used to detect the humidity level by measuring the capacitance and conductivity. A relative humidity of 35%–80% was measured using this sensor (Mraović et al., 2014).
Hydroxyapatite-imidazole-polymer composite films as a proton conductor under no humidified condition
Published in Matthew Laudon, Bart Romanowicz, 2007 Cleantech Conference and Trade Show Cleantech 2007, 2019
Solid polymer electrolyte type fuel cell (PEFC) is one of the candidates for an energy generator with high performance and low production of carbon dioxide [1]. Higher temperature operation (> 100°C) of PEFC will offer higher energy conversion performance [2]. However, typical solid polymer electrolytes (SPE) for PEFC, such as Nafion™, base on the conduction mechanism through the water molecules in the SPE. To keep the water molecules in the SPE, the operation temperature of the fuel cells with the SPE should be lower than 100°C. SPE for the fuel cells with higher operation temperature (> 100°C) requires other proton conduction mechanism that is not depended on water molecules. Some investigations were performed with various systems, Nafion-imidazole (Im)-phosphoric acid [3], Teflon™-Im-phosphoric acid [3], polymer electrolyte membranes based in the polybenzimidazole (PBI) doped with phosphoric acid [4], and PBI doped with Im or 1-methylimidazole and phosphoric acid [5]. Previously, we reported preparation of SPE films based on hydroxyapatite (HAp), Im, and poly(ethylene oxide) (PEO) and their temperature dependence of conductivity and their proton conduction mechanism without water molecules [6]. However, the HAp-Im-PEO films were not stable over 60°C, because the melting point of PEO is about 60°C. Crosslinking of PEO (c-PEO) with tolylene 2, 4-diisocyanate as a cross-linking reagent was effective to keep the dimension of the film. However, the SPE with c-PEO matrix was not acceptable because of their dimension and mechanical instability over 100°C. In this paper we report that preparation of HAp-Im-poly(vinylidene fluoride) (PVdF) composite films and their conductive performance at the temperature over 100°C. PVdF acts as a binder to improve the thermal and mechanical stability of the composite films.
Ionic liquids as demulsifies for crude oil. Synthesis, characterization, and evaluation
Published in Petroleum Science and Technology, 2022
Erik J. Del Ángel-Gómez, Nohra V. Gallardo-Rivas, Ulises Paramo-García, Nancy P. Díaz-Zavala, Ernestina E. Banda-Cruz, Reinaldo D. Martínez-Orozco, Ricardo García-Alamilla
The principal signals of the H- protons of the [EMToSIm][Cl] ILs show-CH=N+R2 aromatic (δ 8.66 ppm, singlet, 21H), -CH=CH- aromatic (δ 7.57 ppm, doublet, 2H), =CH-NR2 aromatic (δ 7.39 ppm, doublet, 2H), -CH=CH- aromatic (δ 7.30 ppm, doublet, 2H), -CH2-N+R3 (δ 4.40 ppm, triplet, 2H), CH2-OTs (δ 3.83 ppm, triplet, 2H), CH3-NR2 (δ 3.75 ppm, singlet, 3H), CH3-(C6H4)- (δ 2.26 ppm, singlet, 3H). The peak present at 4.70 ppm corresponds to the solvent D2O used in this NRM measurement. The representative characteristic of the as-synthesized ionic liquid corresponding to the triplet signal founded at a chemical shift at 4.40 ppm, corresponding to the CH2 binds to the amine group (N) of 1-methylimidazole.
Solution structure of propane and propene dissolved in the ionic liquid 1-butyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide from neutron diffraction with H/D substitution and empirical potential structure refinement modelling
Published in Molecular Physics, 2019
Leila Moura, Mark Gilmore, Samantha K. Callear, Tristan G. A. Youngs, John D. Holbrey
Three H/D-isotopologues of were studied (fully-protiated, fully-deuteriated, and a 1:1 H/D mixture). and the perdeuterated analogue, -, were prepared by metathesis of (and perdeuterated -) with in water (or respectively) followed by drying in vacuo. - was prepared by N-alkylation of 1-methylimidazole- with bromobutane- [46]. The density of measured using an Anton Paar DMA 4500 densitometer at 25C was 1.430 g cm3, consistent with the literature [47].
Valence shell electronically excited states of imidazole and 1-methylimidazole
Published in Molecular Physics, 2023
D. M. P. Holland, D. A. Shaw, D. Townsend, I. Powis
In imidazole and 1-methylimidazole, many of the absorption bands associated with Rydberg states display accompanying vibrational structure. Since the molecular geometry of a Rydberg state is generally similar to that of the ionic state onto which the series converges, the Franck-Condon factors connecting the ground and Rydberg state are expected to be similar to those connecting the ground and corresponding ionic state. Thus, the assignments for the vibrational structure appearing in the photoabsorption spectrum may be guided through comparison with those for the associated photoelectron band.