Azobenzene-functionalized polymers by ring-opening metathesis polymerization for high dielectric and energy storage performance

Abstract

Block copolymers with push–pull azobenzene pendants and core–shell nanostructures exhibited high and regulated dielectric constants by photoisomerization of azobenzene groups, low dielectric loss, and high energy density.

Synthesis of polar polynorbornenes with high dielectric relaxation strength as candidate materials for dielectric applications

“…This is also due to the materials' attractive optical and electro-optic properties, 18 good mechanical and adhesive properties, [19][20][21] multi-shape memory effects, 22 and excellent dielectric behavior. [23][24][25][26][27][28] To increase the dielectric permittivity, functional moieties with large dipole moments as side chains have typically been considered. 29 For instance, Feast reported the synthesis of poly[2,3-bis(trifluoromethyl)norbornadiene] and its dielectric and pyroelectric properties.…”

Azobenzene-containing Alternating and Random Metathesis Copolymers toward Gaining More Insight into Photoisomerization Properties

“…The photoresponsive property of an azobenzene-containing polymer (azo-polymer) is one of the most attractive features due to the highly efficient trans–cis and cis–trans photoisomerization. − Generally, the more stable trans-isomer can undergo photoisomerization to form the cis-isomer upon irradiation with ultraviolet (UV) light, but this process is reversed by visible (vis) light irradiation back to trans-isomer. − Based on this, azo units are usually incorporated into the main chain − or side chain − of polymers to construct the well-defined functional polymeric materials by diverse synthetic methods. Actually, the polymer with azo motifs on the main chain displayed more absorbing physicochemical properties.…”

Probing Atomistic Behavior To Unravel Dielectric Phenomena in Charge Transfer Cocrystals

“…Compounds consisting of polar molecules therefore display large dielectric constants in their liquid state and with drastic reduction upon solidification . However, the majority of insulating systems used in practice are solids, which can be broadly classified into three groups, namely organic materials, − inorganic materials, − and synthetic polymers. − Among them, organic dielectric materials possess many attractive features such as higher flexibility, low-cost processing feasibility, smooth surface and low surface energy , compared with the usually employed inorganic and ceramic-based dielectrics, making the former better substitutes. The low surface energy of organic dielectrics results in a cleaner interface and reduced interface traps, causing a reduction in their operating threshold voltages compared with their inorganic counterparts. , Despite all these advantages, one major drawback of organic dielectrics is their very low dielectric constants in comparison to inorganic materials which limits their wider potential applications. , …”

“…Chemical-shift anisotropy tensor, spin−lattice relaxation time, and molecular correlation time are of paramount importance to determine the structure and dynamics of a molecule. 38−40 For the first time, spin−lattice relaxation and molecular correlation times obtained from 13 C solid-state nuclear magnetic resonance (SSNMR) spectroscopy have been very useful for the structural characterization and exploration of molecular dynamics at the atomic scale in such materials. This also has wide-ranging applications, from glass 41 to biopolymers 42−45 and biomedicine.…”

“…This also has wide-ranging applications, from glass 41 to biopolymers 42−45 and biomedicine. 46−50 Herein in this study we have utilized 13 C SSNMR spectroscopic techniques to confirm the stationary state of NNA in its single crystal structure and its transformation to the dynamic state upon cocrystallization with TAPB and TMB donors. S1).…”