Improved thermomechanical and electrical properties of reduced graphene oxide reinforced polyaniline - dodecylbenzenesulfonic acid/divinylbenzene nanocomposites

Doping Engineering of Conductive Polymers and Their Application in Physical Sensors for Healthcare Monitoring

Physical sensors have emerged as a promising technology for real-time healthcare monitoring, which tracks various physical signals from the human body. Accurate acquisition of these physical signals from biological tissue requires excellent electrical conductivity and long-term durability of the sensors under complex mechanical deformation. Conductive polymers, combining the advantages of conventional polymers and organic conductors, are considered ideal conductive materials for healthcare physical sensors due to their intrinsic conductive network, tunable mechanical properties, and easy processing. Doping engineering has been proposed as an effective approach to enhance the sensitivity, lower the detection limit, and widen the operational range of sensors based on conductive polymers. This approach enables the introduction of dopants into conductive polymers to adjust and control the microstructure and energy levels of conductive polymers, thereby optimizing their mechanical and conductivity properties. This review article provides a comprehensive overview of doping engineering methods to improve the physical properties of conductive polymers and highlights their applications in the field of healthcare physical sensors, including temperature sensors, strain sensors, stress sensors, and electrophysiological sensing. Additionally, the challenges and opportunities associated with conductive polymer-based physical sensors in healthcare monitoring are discussed.

Electrodeposition preparation of NiCo2S4 nanoparticles on N-doped activated carbon modified graphene film for asymmetric all-solid-state supercapacitors

In this work, NiCo2S4 nanoparticles were anchored on the surface of nitrogen doped activated carbon modified graphene (GNAC) by simple electrodeposition to prepare GNAC/NiCo2S4-15 composite electrode materials for high-performance supercapacitors....

Effect of Aminosilane Coupling Agent-Modified Nano-SiO2 Particles on Thermodynamic Properties of Epoxy Resin Composites

From the perspective of improving the thermodynamic properties of epoxy resin, it has become the focus of research to enhance the operational stability of GIS (Gas Insulated Substation) basin insulators for UHV (Ultra-High Voltage) equipment. In this paper, three aminosilane coupling agents with different chain lengths, (3-Aminopropyl)trimethoxysilane (KH550), Aminoethyl)-γ-aminopropyltrimethoxysilane (KH792) and 3-[2-(2-Aminoethylamino)ethylamino]propyl-trimethoxysilane (TAPS), were used to modify nano-SiO2 and doped into epoxy resin, respectively, using a combination of experimental and molecular dynamics simulations. The experimental results showed that the surface-grafted KH792 model of nano-SiO2 exhibited the most significant improvement in thermal properties compared with the undoped nanoparticle model. The storage modulus increased by 276 MPa and the Tg increased by 61 K. The simulation results also showed that the mechanical properties of the nano-SiO2 surface-grafted KH792 model were about 3 times higher than that of the undoped nanoparticle model, the Tg increased by 36.5 K, and the thermal conductivity increased by 24.5%.

Construction and Mechanism Analysis of a Self-Assembled Conductive Network in DGEBA/PEI/HRGO Nanocomposites by Controlling Filler Selective Localization

Herein, a feasible and effective approach is developed to build an electrically conductive and double percolation network-like structure via the incorporation of highly reduced graphene oxide (HRGO) into a polymer blend of diglycidyl ether of bisphenol A/polyetherimide (DGEBA/PEI). With the assistance of the curing reaction-induced phase separation (CRIPS) technique, an interconnected network of HRGO is formed in the phase-separated structure of the DGEBA/PEI polymer blend due to selective localization behavior. In this study, HRGO was prepared from a unique chemical reduction technique. The DGEBA/PEI/HRGO nanocomposite was analyzed in terms of phase structure by content of PEI and low weight fractions of HRGO (0.5 wt.%). The HRGO delivered a high electrical conductivity in DGEBA/PEI polyblends, wherein the value increased from 5.03 × 10⁻¹⁶ S/m to 5.88 S/m at a low content of HRGO (0.5 wt.%). Furthermore, the HRGO accelerated the curing reaction process of CRIPS due to its amino group. Finally, dynamic mechanical analyses (DMA) were performed to understand the CRIPS phenomenon and selective localization of HRGO reinforcement. The storage modulus increased monotonically from 1536 MPa to 1660 MPa for the 25 phr (parts per hundred in the DGEBA) PEI polyblend and reached 1915 MPa with 0.5 wt.% HRGO reinforcement. These simultaneous improvements in electrical conductivity and dynamic mechanical properties clearly demonstrate the potential of this conductive polyblend for various engineering applications.

3D printed graphene-based self-powered strain sensors for smart tires in autonomous vehicles

The transition of autonomous vehicles into fleets requires an advanced control system design that relies on continuous feedback from the tires. Smart tires enable continuous monitoring of dynamic parameters by combining strain sensing with traditional tire functions. Here, we provide breakthrough in this direction by demonstrating tire-integrated system that combines direct mask-less 3D printed strain gauges, flexible piezoelectric energy harvester for powering the sensors and secure wireless data transfer electronics, and machine learning for predictive data analysis. Ink of graphene based material was designed to directly print strain sensor for measuring tire-road interactions under varying driving speeds, normal load, and tire pressure. A secure wireless data transfer hardware powered by a piezoelectric patch is implemented to demonstrate self-powered sensing and wireless communication capability. Combined, this study significantly advances the design and fabrication of cost-effective smart tires by demonstrating practical self-powered wireless strain sensing capability.

Graphene-based nano composites and their applications. A review

The purpose of the current review article is to present a comprehensive understanding regarding pros and cons of graphene related nanocomposites and to find ways in order to improve the performance of nanocomposites with new designs. Nanomaterials including GR are employed in industrial applications such as supercapacitors, biosensors, solar cells, and corrosion studies. The present article has been prepared in three main categories. In the first part, graphene types have been presented, as pristine graphene, graphene oxide and reduced graphene oxide. In the second part, nanocomposites with many graphene, inorganic and polymeric materials such as polymer/GR, activated carbon/GR, metal oxide/GR, metal/graphene and carbon fibre/GR have been investigated in more detail. In the third part, the focus in on the industrial applications of GR nanocomposite, including super capacitors, biosensors, solar cells, and corrosion protection studies.

Well-defined poly(1,5-diaminoanthraquinone)/reduced graphene oxide hybrids with superior electrochemical property for high performance electrochemical capacitors

Conducting polymers and their hybrids have attracted significant attention in electrochemical capacitors due to their unique electrochemical properties. However, the poorer cycle life and lower rate capability have greatly restricted their practical applications. Herein, well-defined poly(1,5-diaminoanthraquinone)/reduced graphene oxide hybrids (PDAA/rGO) with excellent electrochemical performance were successfully prepared via in-situ chemical oxidation polymerization of 1,5-diaminoanthraquinone (DAA) using HClO₄ as initiator and (NH₄)₂S₂O₈ as oxidant in organic solvent mixture at room 25 °C. The electrochemical tests showed that the optimized one, PDAA/rGO S-2 with PDAA nanoparticles of 50 nm uniformly immobilized, possessed the specific capacitance of 617F g^-1 at the current density of 1 A g^-1 in 1.0 mol L^-1 H₂SO₄ electrolyte and outstanding rate capability with the capacitance retention of 70% even at a high current density of 20 A g^-1. Moreover, superior cycle life was achieved to about 124% of its initial capacitance at 100 mV s^-1 after 15,000 cycles without attenuation, and the symmetric solid-state supercapacitor (SSC) based on the PDAA/rGO S-2 electrodes remained 79% of its initial specific capacitance after 15,000 CV cycles.