Flexible Ultrahigh-Temperature Polymer-Based Dielectrics with High Permittivity for Film Capacitor Applications

Engineering natural based nanocomposite inks via interface interaction for extrusion 3D printing

Nanocomposites and low-viscous materials lack translation in additive manufacturing technologies due to deficiency in rheological requirements and heterogeneity of their preparation. This work proposes the chemical crosslinking between composing phases as a universal approach for mitigating such issues. The model system is composed of amine-functionalized bioactive glass nanoparticles (BGNP) and light-responsive methacrylated bovine serum albumin (BSAMA) which further allows post-print photocrosslinking. The interfacial interaction was conducted by 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide crosslinking agent and N-Hydroxysuccinimide between BGNP-grafted amines and BSAMA's carboxylic groups. Different chemical crosslinking amounts and percentages of BGNP in the nanocomposites were tested. The improved interface interactions increased the elastic and viscous modulus of all formulations. More pronounced increases were found with the highest crosslinking agent amounts (4 % w/v) and BGNP concentrations (10 % w/w). This formulation also displayed the highest Young's modulus of the double-crosslinked construct. All composite formulations could effectively immobilize the BGNP and turn an extremely low viscous material into an appropriate inks for 3d printing technologies, attesting for the systems' tunability. Thus, we describe a versatile methodology which can successfully render tunable and light-responsive nanocomposite inks with homogeneously distributed bioactive fillers. This system can further reproducibly recapitulate phases of other natures, broadening applicability.

Enhancing dielectric and mechanical properties of poly(arylene ether nitrile) based composites by introducing low content “core-shell” like structured MXene&PDA@ BaTiO3

Polyarylene ether nitrile (PEN) based composites combined MXene, Polydopamine (PDA) and barium titanate (BaTiO3, BT) with “core-shell”-like structure were developed successfully in this work, and then incorporating into the PEN matrix to form the PEN/MXene&PDA@BT nanocomposite films through the solution casting method. The novel MXene&PDA@BT nanoparticles were characterized by the Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Then the structure and properties of the obtained PEN/MXene&PDA@BT nanocomposites are studied in detail. The results show that the modification of PDA improved the dispersibility of MXene nanosheets and BT nanoparticles in the PEN matrix, resulting in the enhancement of mechanical and dielectric properties. The research results reveal that when the content of MXene&PDA@BT is 1%, the tensile strength and modulus reached 114.15 MPa and 3015.74 MPa, respectively. Most important, the PEN based nanocomposites exhibit the outstanding frequency in dependent dielectric properties, including high dielectric constant (5.08 at 1 kHz) and low dielectric loss (0.0178 at 1 kHz). These results indicate that the PEN/MXene&PDA@BT composite films are greatly significant for using as the constructing high performance dielectric materials.

X-ray-Based Spectroscopic Techniques for Characterization of Polymer Nanocomposite Materials at a Molecular Level

This review provides detailed fundamental principles of X-ray-based characterization methods, i.e., X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, and near-edge X-ray absorption fine structure, and the development of different techniques based on the principles to gain deeper understandings of chemical structures in polymeric materials. Qualitative and quantitative analyses enable obtaining chemical compositions including the relative and absolute concentrations of specific elements and chemical bonds near the surface of or deep inside the material of interest. More importantly, these techniques help us to access the interface of a polymer and a solid material at a molecular level in a polymer nanocomposite. The collective interpretation of all this information leads us to a better understanding of why specific material properties can be modulated in composite geometry. Finally, we will highlight the impacts of the use of these spectroscopic methods in recent advances in polymer nanocomposite materials for various nano- and bio-applications.

Dielectric properties of solution-processed BaTiO3–styrene butadiene styrene nanocomposite films

Polymer–ceramic nanocomposite films comprising ceramic nanoparticles dispersed in a polymer matrix (0–3 composites) have garnered increasing interest due to their superior performance characteristics, and can be used in flexible modern electronics and energy storage systems.

Self-Toughening and Self-Enhancement Poly(arylene ether nitrile) with Low Dielectric Constant by Solid Crosslinking Reaction

A novel poly(arylene ether nitrile) terminated with hydroxyl groups (PEN-OH) was synthesized successfully. The effects of heat-treatment temperature on the thermal properties, mechanical properties, and dielectric properties of the PEN-OH films were studied in detail. Due to the cross-linking reaction occurring, at high temperature, among the nitrile groups on the side of the PEN-OH main chain to form a structurally stable triazine ring, the structure of materials changes from a linear structure to a bulk structure. Thus, the thermal properties and mechanical properties were improved. In addition, the occurrence of cross-linking reactions can reduce the polar groups in the material, leading to the decrease of dielectric constant. As the heat-treatment temperature increased, the glass-transition temperature increased from 180.6 °C to 203.6 °C, and the dielectric constant decreased from 3.4 to 2.8 at 1 MHz. Proper temperature heat-treatment could improve the tensile strength, as well as the elongation, at the break of the PEN-OH films. Moreover, because of the excellent adhesive property of PEN-OH to copper foil, a double-layer flexible copper clad laminate (FCCL) without any adhesives based on PEN-OH was prepared by a simple hot-press method, which possessed high peel strength with 1.01 N/mm. Therefore, the PEN-OH has potential applications in the electronic field.

Component Adjustment of Poly(arylene ether nitrile) with Sulfonic and Carboxylic Groups for Dielectric Films

Poly(arylene ether nitrile)s with sulfonic and carboxylic groups (SCPEN) were synthesized to investigate their electrical properties. This new series of copolymers were prepared by copolymerization of phenolphthalein, potassium hydroquinonesulfonate, and 2,6-difluorobenzonitrile, in different mole ratios. Their thermal, mechanical and dielectric properties were investigated in detail. By adjusting the composition of sulfonic and carboxylic groups, it can be concluded that the dielectric constant increases with the increase of sulfonic groups, and mechanical and thermal properties improve with the increase of carboxylic groups. The as-prepared SCPEN films show potential applications in electronic storage materials, which provide insights into the correlation of SCPEN electrical properties with its chemical structure. The structure–property relationship is established to broaden the application of functionalized PEN. Furthermore, SCPEN with rich polar groups may also be used as the polymer matrix to increase the interaction with the filler surface, ensuring a better dispersion of filler in the matrix. This provides a reference for the development of high dielectric materials.

Poly(arylene ether nitrile) Composites with Surface-Hydroxylated Calcium Copper Titanate Particles for High-Temperature-Resistant Dielectric Applications

In order to develop high-performance dielectric materials, poly(arylene ether nitrile)-based composites were fabricated by employing surface-hydroxylated calcium copper titanate (CCTO) particles. The results indicated that the surface hydroxylation of CCTO effectively improved the interfacial compatibility between inorganic fillers and the polymer matrix. The composites exhibit not only high glass transition temperatures and an excellent thermal stability, but also excellent flexibility and good mechanical properties, with a tensile strength over 60 MPa. Furthermore, the composites possess enhanced permittivity, relatively low loss tangent, good permittivity-frequency stability and dielectric-temperature stability under 160 °C. Therefore, it furnishes an effective path to acquire high-temperature-resistant dielectric materials for various engineering applications.

Enhanced Dielectric and Mechanical Properties of Ternary Composites via Plasticizer-Induced Dense Interfaces

High overall performance, including high dielectric constant, low loss, high breakdown strength, fine flexibility, and strong tensile properties, is difficult to achieve simultaneously in polymer nanocomposites. In our prior work, we modified the surfaces of alpha-SiC nanoparticles and chemically cross-linked the polymeric matrix to simultaneously promote the dielectric and mechanical properties of composites. In this work, a novel strategy of high-temperature plastification towards a polymeric matrix has been proposed to fabricate ternary nanocomposites with balanced dielectric and mechanical characteristics by the solution cast method in order to reduce costs and simplify steps during large-scale preparation. Poly(vinylidene fluoride-chlorotrifluoroethylene) with inner double bonds as matrix, unfunctionalized alpha-SiC nanoparticles (NPs) as filler, and dibutyl phthalate (DBP) as plasticizer were employed. By introducing DBP and high-temperature treatment, the dispersion of NPs and the degree of compactness of the interface regions were both improved due to the reduced cohesion of the fluoropolymer, resulting in an increase in the dielectric constant (by 30%) and breakdown strength (by 57%) as well as the lowering of loss (by 30%) and conductivity (by 16%) in nanocomposites. Moreover, high-temperature plastification contributed to the promotion of flexible and tensile properties. This work might open the door to large-scale fabrication of nanocomposite dielectrics with high overall properties through the cooperation of the plasticizer and high temperature.

Post Self-Crosslinking of Phthalonitrile-Terminated Polyarylene Ether Nitrile Crystals

A novel phthalonitrile-terminated polyaryl ether nitrile (PEN-Ph) was synthesized and characterized. The crystallization behavior coexisting with the crosslinking behavior in the PEN-Ph system was confirmed by rheological measurements. DSC was applied to study the crystallization kinetics and crosslinking reaction kinetics. Through the Avrami equation modified by Jeziorny, the nonisothermal crystallization kinetics were analyzed, and the Avrami exponent of about 2.2 was obtained. The analysis results of more intuitive polaring optical microscopy (POM) and SEM indicated that the shape of the crystals is similar to spherical. Moreover, the activation energy of the crystallization behavior and crosslinking behavior were obtained by the Kissinger method, and the values were about 152.7 kJ·mol-1 and 174.8 kJ·mol-1, respectively. This suggests that the activation energy of the crystallization behavior is lower than that of the crosslinking behavior, indicating that the crystallization behavior is more likely to occur than the crosslinking behavior and the crystals of PEN-Ph can be self-crosslinked to form single-polymer composites.