Molecular Design and Characterization of Ionic Monomers with Varying Ion Pair Interaction Energies

Matsuno, Ryosuke; Kokubo, Yota; Kumagai, Shinji; Takamatsu, Shigeaki; Hashimoto, Kazunobu; Takahara, Atsushi

doi:10.1021/acs.macromol.9b02731

Cited by 12 publications

(15 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An "extended" Hofmeister series might also use organic ions to enhance the hydrophobic nature of the charge. For example, ions used in ionic liquids 42 are often quite hydrophobic.…”

Section: ■ Introductionmentioning

confidence: 99%

Precision Doping of Polyelectrolyte Complexes: Insight on the Role of Ions

2020

View full text Add to dashboard Cite

The properties of polyelectrolyte complexes and coacervates, both termed PECs, are influenced strongly by their ion and water content. Water plasticizes PECs, reducing their modulus and glass transition temperature, T g. In this work, a hydrated PEC with a T g near room temperature, made from poly(diallyldimethylammonium) (PDADMA) and poly(styrene sulfonate) (PSS) was precisely doped with 22Na-labeled sodium salts along a Hofmeister series. A distinctive change in the rate of doping versus added salt concentration was observed for all salts. This transition was interpreted to reflect a change in ion-accessible volume coinciding with a change in the role of added salt from counterions for the polyelectrolytes, paired directly and within one water molecule of the charge on the polymer backbone, to a mix of counterions and co-ions, which do not have a specific location within the PEC. Isothermal calorimetry for PEC made in, and doped by, NaCl showed two clear regions for enthalpy change, ΔH, before and after the doping transition. The higher ΔH region was correlated with the counterion role, an indirect measure of the location of ions within the PEC.

show abstract

“…An "extended" Hofmeister series might also use organic ions to enhance the hydrophobic nature of the charge. For example, ions used in ionic liquids 42 are often quite hydrophobic.…”

Section: ■ Introductionmentioning

confidence: 99%

Precision Doping of Polyelectrolyte Complexes: Insight on the Role of Ions

2020

View full text Add to dashboard Cite

show abstract

“…The BT100 particles indicated high ε r and high dielectric loss. Both values increased in the low-frequency region because of the interfacial polarization associated with the mobile charges between particles. − Thus, there is ion migration occurring from the BT100 particles. However, both ε r and dielectric loss of the silica-coated BT100 decreased, as the amount of silica coating increased.…”

Section: Resultsmentioning

confidence: 99%

Actuator Performance of a Hydrogenated Carboxylated Acrylonitrile–Butadiene Rubber/Silica-Coated BaTiO₃ Dielectric Elastomer

et al. 2020

Self Cite

View full text Add to dashboard Cite

We synthesized silica-coated barium titanate (BaTiO 3 ) particles with different silica shell thicknesses and evaluated the effect of silica coating on the relative dielectric properties of silica-coated BaTiO 3 particles. Furthermore, composite elastomers were prepared using hydrogenated carboxylated acrylonitrile−butadiene rubber (HXNBR) with a high relative dielectric constant (ε r ) and silica-coated BaTiO 3 particles, and their performance as an actuator was evaluated. Both ε r and relative dielectric loss of non-coated BaTiO 3 particles increased at low frequencies (<200 Hz) associated with ionic conduction. However, ε r and relative dielectric loss were reduced for the silica-coated BaTiO 3 particles with thick silica shells, indicating that silica coating reduced ion migration. The dielectric breakdown strength increased with the thickness of the silica shell; it increased up to 80 V/μm for HXNBR/silica-coated BaTiO 3 particles with 20 nm-thick silica shells. The maximum generated stress, strain, and output energy density of the composite elastomer with HXNBR (with a high relative constant) and silica-coated BaTiO 3 were 1.0 MPa, 7.7%, and 19.4 kJ/m 3 , respectively. In contrast, the values of the same parameters for a reference elastomer (acrylic/BaTiO 3 ; with low ε r ) were 0.4 MPa, 6.7%, and 6.8 kJ/m 3 at the dielectric breakdown strength of 70 V/μm. The results indicated that the elastomers composed of HXNBR and silica-coated BaTiO 3 exhibited higher generated stress, strain, and output energy density than elastomers for conventional dielectric actuators.

show abstract

“…The sample preparation scheme for the measurement of relative dielectric constants, dielectric loss at 100 Hz, and volume resistivity at 100 V is shown in Figure S15 (see the Information); 100 Hz was selected because the frequency shows the orientation of polar groups in the polymer − without being affected by impurities and is the target for actuator drive . In addition, 100 Hz is a stable frequency that can be measured with the electrodes we used (Figure S16).…”

Section: Methodsmentioning

confidence: 99%

Highly Dielectric Rubber Bearing Cyanoethyl Group with Various Side-Chain Structures

et al. 2020

Self Cite

View full text Add to dashboard Cite

We synthesized rubbers including cyanoethyl groups and evaluated the effect of side-chain structures on dielectric properties, electrical properties at room temperature, and glass-transition temperatures (T g). New monomers including cyanoethyl were synthesized via the thiol–ene reaction and esterification; these included 3-((2,4-dicyanobutyl)thio)propyl acrylate (DCEA3M) and 6-((2,4-dicyanobutyl)thio)hexyl acrylate (DCEA6M). Copolymers consisting of 2-cyanoethyl acrylate (CEA) and DCEA3M or DCEA6M were synthesized to obtain a rubber with a high dielectric constant. Reference copolymer samples with varying CN wt % consisted of CEA and acrylate monomers were also synthesized. Undesirable gelation occurred during polymerization of monomers including cyanoethyl; however, gelation could be resolved by changing the monomer concentration and reaction time. The copolymers exhibited a T g of 5 °C or below, and the relative dielectric constant at 100 Hz was above 10. pDCEA3M exhibited the highest dielectric constant of 20.3 corresponding to a high CN wt % of 20.6%, and pDCEA6M displayed the lowest T g of −33.2 °C due to the internal plasticization corresponding to the long side chain; however, the dielectric losses of pDCEA3M and pDCEA6M were as high as 3.2 and 7.7, respectively. On the other hand, p(CEA–DCEA3M) and p(CEA–DCEA6M) copolymerized with CEA could reduce the dielectric loss (∼2.4) while maintaining high dielectric constant (16.3–18.9) and low T g (−22.9––3.36 °C). The copolymers also exhibited a high dielectric constant at a comparable volume resistivity (1010–1012 Ω·cm) compared to commercial rubbers. Such elastomers with high dielectric constant and low dielectric loss are expected to improve the performance of soft actuators.

show abstract

Molecular Design and Characterization of Ionic Monomers with Varying Ion Pair Interaction Energies

Cited by 12 publications

References 40 publications

Precision Doping of Polyelectrolyte Complexes: Insight on the Role of Ions

Precision Doping of Polyelectrolyte Complexes: Insight on the Role of Ions

Actuator Performance of a Hydrogenated Carboxylated Acrylonitrile–Butadiene Rubber/Silica-Coated BaTiO₃ Dielectric Elastomer

Highly Dielectric Rubber Bearing Cyanoethyl Group with Various Side-Chain Structures

Contact Info

Product

Resources

About

Molecular Design and Characterization of Ionic Monomers with Varying Ion Pair Interaction Energies

Cited by 12 publications

References 40 publications

Precision Doping of Polyelectrolyte Complexes: Insight on the Role of Ions

Precision Doping of Polyelectrolyte Complexes: Insight on the Role of Ions

Actuator Performance of a Hydrogenated Carboxylated Acrylonitrile–Butadiene Rubber/Silica-Coated BaTiO3 Dielectric Elastomer

Highly Dielectric Rubber Bearing Cyanoethyl Group with Various Side-Chain Structures

Contact Info

Product

Resources

About

Actuator Performance of a Hydrogenated Carboxylated Acrylonitrile–Butadiene Rubber/Silica-Coated BaTiO₃ Dielectric Elastomer