Polymer electrolyte liquid crystal system for improved optical and electrical properties

Said, Suhana Mohd; Zulkifli, Ahmad Zulazlan Shah; Kamarudin, Muhammad Akmal; Mainal, Azizah; Subramanian, Balamurugan; Mohamed, N. S.

doi:10.1016/j.eurpolymj.2015.02.004

Cited by 11 publications

(29 citation statements)

References 33 publications

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“…While the unstretched sample exhibited no variation, as expected, the stretched sample showed a well-defined 3cos2θ − 1 orientation dependence, where θ is the angle between the stretch direction and the external magnetic field. This angular dependence reflects the anisotropy induced in the magnetic dipole-dipole interaction (primarily between 7 Li and 1 H) by stretching. The short-range environment of the Li ions is also affected by stretching, as was demonstrated by changes in low temperature nuclear quadrupole splitting, which is sensitive to Li-O coordination.…”

Section: 91mentioning

confidence: 98%

“…In, 67 an additional indication was found of long-range structural change occurring as a result of stretching, via the angular dependence of the linewidth of the 7 Li-NMR spectra at 305 K (32 • C). While the unstretched sample exhibited no variation, as expected, the stretched sample showed a well-defined 3cos2θ − 1 orientation dependence, where θ is the angle between the stretch direction and the external magnetic field.…”

Section: 91mentioning

confidence: 99%

“…In addition, solid electrolytes are safer than liquid electrolytes as they do not have a leakage problem and because of their nontoxic, low-vaporpressure, and non-flammable properties. [1][2][3][4][5][6][7] Ion-polyether complexes (or polymer electrolytes) were first discovered by Fenton, Parker and Wright in 1973. 8 Since then, such complexes have been prepared with many different monatomic ions and indeed many different polymeric ligands.…”

Section: Solid Polymer Electrolytes-structure and Mechanism Of Ion Trmentioning

confidence: 99%

“…The conductivity of the reported electrolyte, while low (about 10 −5 mS/cm), is still 30 times that of the comparable PEO/Li + complex crystal at room temperature. The effect on the dynamics of Li + ions and the PEO segments in the nanochannel, has been studied by combining the 7 Li 2D-exchange NMR with 2 H NMR. It was found that the PEO chain in the nanochannel of the α-CDDPEO/Li+ complex consists primarily of the ttg conformational sequences and the discrete four-site jump motion occurs when the temperature reaches 290 K. Analysis of the NMR patterns suggests, that when the jump motions occur, the other parts of the PEO chains in the nanochannel remain static.…”

Section: 91mentioning

confidence: 99%

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Review—On Order and Disorder in Polymer Electrolytes

Golodnitsky

Strauss

Greenbaum

2015

J. Electrochem. Soc.

203

135

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This contribution presents an overview of more than three-decades-long studies of the structure and mechanism of ion conduction in polyethylene-oxide-based solid polymer electrolytes. Conductivity in polymer electrolytes has long been viewed as confined to the amorphous phase above the glass-transition temperature (Tg). Above Tg, polymer chain motion creates a dynamic, disordered environment that was thought to play a critical role in facilitating ion transport. Difficulty of finding the amorphous polymer with sufficient ionic conductivity has raised the fundamental question of whether polymer electrolytes are intrinsically inferior to other electrolytes in terms of their charge-transport capability. Recently, enhanced ionic conductivity has been detected in ordered (longitudinally stretched and cast under gradient magnetic field) polymer electrolytes, in crystalline ion-polyether 1:6 complexes and polymer-in-salt electrolytes. These results have opened a new trend in the search for ion transport in solid polymer electrolytes. The very latest publications present new hybrid-and block-co-polymers, a new class of functional materials (polymerized ionic liquids), and new promising approaches aimed at the development of polymer-based superionic conductors with rigid nanochannel architectures that enable rapid ion transport decoupled from segmental relaxation. Solid Polymer Electrolytes-Structure and Mechanism of Ion TransportMuch research deals with high-ionic-conductive polymer electrolytes because of their current and potential applications as electrochromic and temperature-sensitive printed electronics devices, biomedical sensors, supercapacitors, solar cells and batteries. Polymer electrolytes offer pronounced advantages over conventional liquid electrolytes. These include: a versatile shape, mechanical strength and stable contact between the electrode and electrolyte interfaces. In addition, solid electrolytes are safer than liquid electrolytes as they do not have a leakage problem and because of their nontoxic, low-vaporpressure, and non-flammable properties. [1][2][3][4][5][6][7] Ion-polyether complexes (or polymer electrolytes) were first discovered by Fenton, Parker and Wright in 1973. 8 Since then, such complexes have been prepared with many different monatomic ions and indeed many different polymeric ligands. Armand in 1979 recognized that Li + -polyether complexes could be used as solid electrolytes in electrochemical devices. 9The classic polymer electrolyte comprises organic macromolecules (usually polyether polymer) that are complexed with inorganic salts. The polymer matrix must contain a Lewis base (e.g. ethylene-oxide unit, -OCH 2 CH 2 -) to solvate the lithium salt. The salt-solvent mixing entropy consists mainly of two components: translational and configurational. Contrary to the case of water, the mixing entropy for the formation of polymer electrolytes is small or even positive. The incorporation of salts into the polymer inevitably reduces the freedom of polymer-chain motion, thus causing ...

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Section: 91mentioning

confidence: 98%

Section: 91mentioning

confidence: 99%

Section: Solid Polymer Electrolytes-structure and Mechanism Of Ion Trmentioning

confidence: 99%

Section: 91mentioning

confidence: 99%

See 2 more Smart Citations

Review—On Order and Disorder in Polymer Electrolytes

Golodnitsky

Strauss

Greenbaum

2015

J. Electrochem. Soc.

203

135

View full text Add to dashboard Cite

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“…The chain interlocking forms cylinders enabling stable coordination with Li + ions, but the ions are trapped into the cylinders at high salt concentration, restricting the mobility of the polymer chains, and consequently the ionic conductivity drops . At low salt concentration, it has been demonstrated that amorphous phases of PEO provide an adequate ionic conduction, whence a number of synthetic strategies have been adopted to prepare primarily amorphous phases, including the synthesis of comb polymers and block copolymers . However, their dimensional properties such as mechanical strength and flexibility were low, whence ion conduction also decreased due to loss of mobility of polymer chains.…”

Section: Introductionmentioning

confidence: 99%

Design of a Zwitterion Polymer Electrolyte Based on Poly[poly (ethylene glycol) methacrylate]: The Effect of Sulfobetaine Group on Thermal Properties and Ionic Conduction

Guzmán

Nava

Vazquez‐Arenas

et al. 2017

Macromolecular Symposia

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Polymer electrolytes are expected to play an overriding role in the development of sustainable lithium ion batteries. In this study, amorphous poly(poly(ethylene glycol) methacrylate) (pPEGMA) and pPEGMA functionalized with sulfobetaine pendants (pMPS8) are synthesized, and subsequently formulated with LiPF6 to be assessed as solid polymer electrolytes (SPE). The polymer properties are investigated using Differential scanning calorimetry (DSC), X‐ray diffraction (XRD), Attenuated total reflection Fourier transform infrared (FTIR) and Electrochemical Impedance Spectroscopy (EIS). These experimental analyses are used to account for the effects of a methacrylate‐type polymer as an alternative to improve Li+ mobility across the polymer, and synergic benefits of its functionalization with sulfobetaine groups. pPEGMA displayed a Tg around −49 °C, which increases in the presence of the lithium salt to −38 °C due to the interactions arising between Li+ ions and the polymer, as confirmed by XRD and FTIR characterizations. The ionic conductivity of the pPEGMA/LiPF6 system is 6.92 × 10−6 S cm−1, which denotes a partial dissociation of LiPF6 as a result of the formation of ion pairs, detected by the structural characterization. The functionalization of pPEGMA is an efficient method to decrease the Tg down to −53 °C, suggesting that pMPS8 keeps amorphous pPEGMA matrix allowing mobility of polymer chains by the presence of the sulfobetaine pendants. Evidence of this behavior is determined with the chemical and structural evaluations, and clearly observed in the increase of ionic conductivity by two orders of magnitude. Although the Tg of the pMPS8/LiPF6 system considerably augments to −24 °C, its effects are negligible in ionic conductivity (3.22 × 10−5 S cm−1), indicating that a relatively low stiff backbone arises in pMPS8 structures, which is not influenced by the presence of LiPF6 due to the strong charge delocalization generated by the sulfobetaine groups.

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