Influence of sulfonyl fluoride monomers on the mechanism of emulsion copolymerization with the preparation of proton-conducting membrane precursors

Primachenko, O. N.; Odinokov, A. S.; Marinenko, E. A.; Kulvelis, Yu. V.; Barabanov, V. G.; Кононова, С. В.

doi:10.1016/j.jfluchem.2021.109736

Cited by 8 publications

(9 citation statements)

References 27 publications

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Section: Methodsmentioning

confidence: 99%

“…A perfluorinated copolymer with short side chains, having an equivalent weight (EW) of 890 g-eq/mol, was synthesized by an aqueous-emulsion technique [ 48 ]. A monomer FS-81 (perfluoro-3-octapentensulfonilfluoride) was copolymerized with tetrafluoroethylene (TFE) [ 16 , 48 ]. Membranes were prepared by a solution casting technique using a DMF solution of a –SO 3 Li form of copolymer (2 wt.%), when the solvent was removed at 70–80 °C followed by annealing at 170–200 °C for 1–2 h and reducing to a –SO 3 H form, according to the adopted method [ 18 ].…”

Section: Methodsmentioning

confidence: 99%

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Improving PFSA Membranes Using Sulfonated Nanodiamonds

Shvidchenko,

Odinokov,

Primachenko

et al. 2023

Membranes

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Aquivion®-type perfluorosulfonic acid membranes with a polytetrafluoroethylene backbone and short side chains with sulfonic acid groups at the ends have great prospects for operating in hydrogen fuel cells. To improve the conducting properties of membranes, various types of nanofillers can be used. We prepared compositional Aquivion®-type membranes with embedded detonation nanodiamond particles. Nanodiamonds were chemically modified with sulfonic acid groups to increase the entire amount of ionogenic groups involved in the proton conductivity mechanism in compositional membranes. We demonstrated the rise of proton conductivity at 0.5–2 wt.% of sulfonated nanodiamonds in membranes, which was accompanied by good mechanical properties. The basic structural elements, conducting channels in membranes, were not destroyed in the presence of nanodiamonds, as follows from small-angle neutron scattering data. The prepared compositional membranes can be used in hydrogen fuel cells to achieve improved performance.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Improving PFSA Membranes Using Sulfonated Nanodiamonds

Shvidchenko,

Odinokov,

Primachenko

et al. 2023

Membranes

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“…To prepare the composites, a short side chain PFSA Aquivion ® -type copolymer was synthesized using aqueous emulsion technology [41] through copolymerizing tetrafluoroethylene (TFE) with a perfluorinated sulfonic monomer (perfluoro-3-oxapentenesulfonyl fluoride). The process was conducted in a 0.45 L steel reactor that was maintained at a temperature of 40-60 • C, using an anchor stirrer at a pressure of 0.7-1.3 MPa supplied to the TFE system that was controlled automatically.…”

Section: Experimental 21 Materials Obtaining and Characterizationmentioning

confidence: 99%

“…Here, we used a short side chain copolymer in -SO 2 F form as a precursor, which was obtained through aqueous-emulsion copolymerization of fluoromonomers [41] with an equivalent weight (EW) of 890 g-eq/mol for the SO 2 F groups (melt flow index MFI = 0.80 g/10 min determined on an IIRT-M plastometer at 270 • C, load 2.16 kg, and capillary diameter 2.095 mm).…”

Section: Experimental 21 Materials Obtaining and Characterizationmentioning

confidence: 99%

Electrochemical Properties and Structure of Membranes from Perfluorinated Copolymers Modified with Nanodiamonds

Lebedev,

Kulvelis,

Shvidchenko

et al. 2023

Membranes

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In this study, we aimed to design and research proton-conducting membranes based on Aquivion®-type material that had been modified with detonation nanodiamonds (particle size 4–5 nm, 0.25–5.0 wt. %). These nanodiamonds carried different functional groups (H, OH, COOH, F) that provided the hydrophilicity of the diamond surface with positive or negative potential, or that strengthened the hydrophobicity of the diamonds. These variations in diamond properties allowed us to find ways to improve the composite structure so as to achieve better ion conductivity. For this purpose, we prepared three series of membrane films by first casting solutions of perfluorinated Aquivion®-type copolymers with short side chains mixed with diamonds dispersed on solid substrates. Then, we removed the solvent and the membranes were structurally stabilized during thermal treatment and transformed into their final form with –SO3H ionic groups. We found that the diamonds with a hydrogen-saturated surface, with a positive charge in aqueous media, contributed to the increase in proton conductivity of membranes to a greater rate. Meanwhile, a more developed conducting diamond-copolymer interface was formed due to electrostatic attraction to the sulfonic acid groups of the copolymer than in the case of diamonds grafted with negatively charged carboxyls, similar to sulfonic groups of the copolymer. The modification of membranes with fluorinated diamonds led to a 5-fold decrease in the conductivity of the composite, even when only a fraction of diamonds of 1 wt. % were used, which was explained by the disruption in the connectivity of ion channels during the interaction of such diamonds mainly with fluorocarbon chains of the copolymer. We discussed the specifics of the mechanism of conductivity in composites with various diamonds in connection with structural data obtained in neutron scattering experiments on dry membranes, as well as ideas about the formation of cylindrical micelles with central ion channels and shells composed of hydrophobic copolymer chains. Finally, the characteristics of the network of ion channels in the composites were found depending on the type and amount of introduced diamonds, and correlations between the structure and conductivity of the membranes were established.

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“…Since the nature and chemical characteristics of the membranes are strictly connected to the water transport, it is necessary to increase the number of sulfonic groups per monomeric unit in order to achieve a much higher proton conductivity [ 15 ]. Fluorophosphonic acid monomers, which have higher chemical and thermal stabilities than sulfonic acid moieties, are still rarely investigated [ 16 , 17 , 18 , 19 , 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Tailored Perfluoro Unsaturated Monomers for Potential Applications in Proton Exchange Membrane Preparation

et al. 2021

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The aim of the present work is the synthesis and characterization of new perfluorinated monomers bearing, similarly to Nafion®, acidic groups for proton transport for potential and future applications in proton exchange membrane (PEM) fuel cells. To this end, we focused our attention on the synthesis of various molecules with (i) sufficient volatility to be used in vacuum polymerization techniques (e.g., PECVD)), (ii) sulfonic, phosphonic, or carboxylic acid functionalities for proton transport capacity of the resulting membrane, (iii) both aliphatic and aromatic perfluorinated tags to diversify the membrane polarity with respect to Nafion®, and (iv) a double bond to facilitate the polymerization under vacuum giving a preferential way for the chain growth of the polymer. A retrosynthetic approach persuaded us to attempt three main synthetic strategies: (a) organometallic Heck-type cross-coupling, (b) nucleophilic displacement, and (c) Wittig–Horner reaction (carbanion approach). Preliminary results on the plasma deposition of a polymeric film are also presented. The variation of plasma conditions allowed us to point out that the film prepared in the mildest settings (20 W) shows the maximum monomer retention in its structure. In this condition, plasma polymerization likely occurs mainly by rupture of the π bond in the monomer molecule.

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Influence of sulfonyl fluoride monomers on the mechanism of emulsion copolymerization with the preparation of proton-conducting membrane precursors

Cited by 8 publications

References 27 publications

Improving PFSA Membranes Using Sulfonated Nanodiamonds

Improving PFSA Membranes Using Sulfonated Nanodiamonds

Electrochemical Properties and Structure of Membranes from Perfluorinated Copolymers Modified with Nanodiamonds

Synthesis of Tailored Perfluoro Unsaturated Monomers for Potential Applications in Proton Exchange Membrane Preparation

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