Counterion Dynamics in Polyurethane-Carboxylate Ionomers with Ionic Liquid Counterions

Wang, Shih Wa; Liu, Wenjuan; Colby, Ralph H.

doi:10.1021/cm103548t

Cited by 97 publications

(138 citation statements)

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“…They proposed that higher fractional free volumes depressed the Vogel temperature, T 0 , allowing for ion mobility at temperatures signifi cantly below T g . Colby and co-workers [ 14 ] studied the introduction of mobile imidazolium countercations to polymers containing pendant carboxylate groups. Colby and coworkers [ 14 ] concluded that T g does not completely dominate the ionic conductivities, and segmental relaxation of polymer chains correlated strongly with ionic conductivity.…”

Section: Introductionmentioning

confidence: 99%

“…Colby and co-workers [ 14 ] studied the introduction of mobile imidazolium countercations to polymers containing pendant carboxylate groups. Colby and coworkers [ 14 ] concluded that T g does not completely dominate the ionic conductivities, and segmental relaxation of polymer chains correlated strongly with ionic conductivity. They also revealed that the increased size of the countercation reduced T g and increased the concentration of nontrapped or mobile ions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Alkyl‐Substituted N‐Vinylimidazolium Polymerized Ionic Liquids: Thermal Properties and Ionic Conductivities

Green

Cruz

et al. 2011

Macro Chemistry & Physics

146

189

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Structure-property relationships for polymerized ionic liquids (PILs) relate chemical structure to ionic conductivity and reveal the importance of glass transition temperature ( T g ) and the energy associated with an ion-hopping mechanism for ion conduction for a series of alkyl-substituted vinylimidazolium PILs. The alkyl-substituted vinylimidazolium-based PILs with varying lengths of n -alkyl substituents provide diverse precursors with exchangeable anions to further enhance thermal stability and ionic conductivity. As the anion size increases, regardless of alkyl substituent length, T g decreases and the onset of weight loss, T D , increases. As the length of the alkyl substituent increases, T g decreases for PILs with Br − and BF 4 − counteranions. Ionic conductivity increases over an order of magnitude upon exchange of the counteranion from TfO − < Tf 2 N − . due to their unique combination of physical properties including high thermal stability, wide electrochemical window, negligible vapor pressure, and potentially high ionic conductivities. [3][4][5][6][7] Two particular classes of ILs are polymerizable ILs (PILs) that contain polymerizable functional groups and room temperature ILs (RTILs) with melting temperatures at or below room temperature. [ 8 ] Potential applications have included electrolytes in electromechanical transducers, artifi cial muscle fabrication, and non-volatile solvents for a myriad of chemical reactions. [ 9 ] Chen and Elabd investigated the solution properties and subsequent formation of electrospun fi bers of an imidazolium-containing methacrylate-based PIL. [ 10 ] This study revealed solution properties similar to polyelectrolyte solutions, and electrospun fi bers formed with intermediate fi ber diameters and onset of fi ber formation between polyelectrolyte and neutral polymers. The fi brous mats exhibited promising ionic conductivities at room temperature, and upon swelling with a RTIL, ionic conductivities were on the order of 10 mS cm − 1 . Long and co-workers also investigated the impact of counteranion on the solution and thermal properties of ammoniumbased polyelectrolytes. [ 11 ] Our study revealed the important infl uence of anion selection on the T g of the polyelectrolyte, and we observed polyelectrolyte electrospinning

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Alkyl‐Substituted N‐Vinylimidazolium Polymerized Ionic Liquids: Thermal Properties and Ionic Conductivities

Green

Cruz

et al. 2011

Macro Chemistry & Physics

146

189

View full text Add to dashboard Cite

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“…The increased efficiency of phosphonium versus ammonium polycations was ascribed to their efficient cationic charge distribution (centered on the phosphorus atom, while distributed through adjacent carbons on the ammonium moiety), as demonstrated by calculations, 21,22 which lead to stronger and more stable interactions with the negatively charged nucleic acids.…”

Section: Introductionmentioning

confidence: 95%

Development of Fully Degradable Phosphonium-Functionalized Amphiphilic Diblock Copolymers for Nucleic Acids Delivery

et al. 2018

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To expand the range of functional polymer materials to include fully hydrolytically degradable systems that bear bioinspired phosphorus-containing linkages both along the backbone and as cationic side chain moieties for packaging and delivery of nucleic acids, phosphonium-functionalized polyphosphoester-block-poly(l-lactide) copolymers of various compositions were synthesized, fully characterized, and their self-assembly into nanoparticles were studied. First, an alkyne-functionalized polyphosphoester-block-poly(l-lactide) copolymer was synthesized via a one pot sequential ring opening polymerization of an alkyne-functionalized phospholane monomer, followed by the addition of l-lactide to grow the second block. Second, the alkynyl side groups of the polyphosphoester block were functionalized via photoinitiated thiol–yne radical addition of a phosphonium-functionalized free thiol. The polymers of varying phosphonium substitution degrees were self-assembled in aqueous buffers to afford formation of well-defined core–shell assemblies with an average size ranging between 30 and 50 nm, as determined by dynamic light scattering. Intracellular delivery of the nanoparticles and their effects on cell viability and capability at enhancing transfection efficiency of nucleic acids (e.g., siRNA) were investigated. Cell viability assays demonstrated limited toxicity of the assembly to RAW 264.7 mouse macrophages, except at high polymer concentrations, where the polymer of high degree of phosphonium functionalization induced relatively higher cytotoxicity. Transfection efficiency was strongly affected by the phosphonium-to-phosphate (P+/P–) ratios of the polymers and siRNA, respectively. The AllStars Hs Cell Death siRNA complexed to the various copolymers at a P+/P– ratio of 10:1 induced comparable cell death to Lipofectamine. These fully degradable nanoparticles might provide biocompatible nanocarriers for therapeutic nucleic acid delivery.

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“…24 Importantly, different partial charges and charge distributions have been suggested, where for phosphonium ions the positive charge is centered at the P atom, whereas in the ammonium group is comparatively more distributed through the adjacent carbons, resulting in a weaker cationic charge in the ammonium groups. 21,25 Consequently, in quaternary ammonium moieties the adjacent hydrogen atoms (α-and β-methylene hydrogens) are also more positively charged, which results in stronger hydrogen bonding, further shortening contact distances with their anionic counterions.…”

Section: Phosphonium Versus Ammonium Cations: Similarities Differencmentioning

confidence: 99%

“…Being less electronegative than the adjacent carbons, the phosphorus atom of nBu4P + carries a positive charge (+1.1e) leaving the outer atoms to share (-0.1e). 25 This partially negative shell surrounding the cationic P atom in turn provides a partial shielding which weakens the coulombic interaction with anionic counterions. Conversely, being more electronegative that the bound carbon atoms, in n-Bu4N + nitrogen carries a negative charge (-0.5e) leaving the outer atoms to share (+1.5 e), which results in higher attraction towards anions.…”

mentioning

confidence: 99%

Phosphonium polymers for gene delivery

2017

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Phosphonium salt-containing polymers have very recently started to emerge as attractive materials for the engineering non-viral gene delivery systems. Compared to more frequently utilised ammonium-based polymers, some of these materials can enhance binding of nucleic acid at lower polymer concentration, and mediate good transfections efficiency, with low cytotoxicity. However, for years one of the main hurdles for their widespread application has been the lack of general routes for their synthesis. To date a range of polymerisation techniques have been explored, with the majority of them focussing on radical polymerisation, especially controlled radical polymerisation (CRP) techniques -ATRP, NMP and RAFT polymerisation -both by polymerisation of phosphonium monomers or by post-polymerisation modification of polymer intermediates. This review article aims at discussing key differences and similarities between phosphonium-and other analogous cations, how these affect binding to polynucleotides, and will provide an overview of the phosphonium polymer systems that have been utilised for gene delivery.

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Counterion Dynamics in Polyurethane-Carboxylate Ionomers with Ionic Liquid Counterions

Cited by 97 publications

References 54 publications

Alkyl‐Substituted N‐Vinylimidazolium Polymerized Ionic Liquids: Thermal Properties and Ionic Conductivities

Alkyl‐Substituted N‐Vinylimidazolium Polymerized Ionic Liquids: Thermal Properties and Ionic Conductivities

Development of Fully Degradable Phosphonium-Functionalized Amphiphilic Diblock Copolymers for Nucleic Acids Delivery

Phosphonium polymers for gene delivery

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