Polymer Metal Research Articles

Highly robust soft-rigid connections via mechanical interlocking for assembling ultra-stretchable displays

Stretchable electronic circuits can seamlessly conform to irregular and dynamic surfaces with high integration. However, current stretchable configurations typically have limited stretchability due to the lack of robust connections between soft interconnects and rigid electronics. Here, we printed highly stretchable metal–polymer conductors on thermoplastic elastomers as interconnects. We developed electronic vests with porous surfaces for rigid electronics and introduced polyester hot-melt adhesives to strengthen connections between soft interconnects and rigid electronics. After thermal bonding, the adhesive penetrates the porous surface of electronic vests, creating a mechanical interlock and providing an adhesion force of 8.34 N/cm for the connection (3× higher than conductive adhesives). Thus, rigid electronics of different sizes and different pin counts can form strong connections to soft interconnects, achieving a maximum strain tolerance of ~700% (10× higher than conductive adhesives). We achieved highly integrated ultra-stretchable displays that can withstand stretching up to 220% without dead pixels.

The PolyCraft Polymer–Metal Hybrid Smart Stent System: The Future of Cardiovascular Blood Pressure Management

AbstractTo address the complication of in‐stent restenosis that occurs with traditional stent treatments, this study proposes an innovative hybrid smart stent‐based medical system. This approach allows to overcome the limitations of existing bare metal or polymer‐based smart stents, which interfere with radio frequency signals, less deformability, or do not provide adequate radial support, respectively. The proposed hybrid stent, which uses a Co/Cr–polycaprolactone (PCL)–Co/Cr configuration connected by a unique dual inverted Y‐type connector for metal–polymer integration is integrated with a LC wireless pressure sensor fabricated through a semiconductor process. The fabricated hybrid stent made by laser machining and custom‐made 3D printing, offers excellent properties such as radial strength (0.125 N/mm) and flexibility (2 N mm2) and provides intravascular information to the outside through the integrated sensor without signal degradation. After basic experiments using a phantom, animal experiments are conducted by combining the fabricated sensor with artificial blood vessel, and the results measured by the external antenna system are consistent with the results of a commercial reference sensor. The proposed wireless sensor‐based smart stents and artificial blood vessels aim to gather diverse patient health data for integration with artificial intelligence, laying the groundwork for next‐generation medical innovation.

Material extrusion fabrication of continuous metal wire-reinforced polymer–matrix composites

3D printing via material extrusion is capable of using polymeric materials for a large range of applications. They are generally used, however, for prototyping as opposed to creating functional parts due to their lower mechanical properties in comparison to other materials, such as metals or epoxies, and processing methods, such as compression molding or injection molding. Carbon fiber, glass fiber, and kevlar have been used as reinforcement materials with very positive results in terms of creating functional parts. However, little focus has been placed on metallic wire reinforcement. In this investigation, a novel strategy to manufacture continuous metallic wire-reinforced polymer–matrix composites with increased mechanical properties by material extrusion is presented. A customized multimaterial 3D printer was built and used to fabricate coupons of unidirectionally reinforced Al wire/PLA matrix composites with either 15% or 25% wire volume fraction. The microstructure of the composites was analyzed to understand the formation of porosity during processing. These results also showed the potential of the manufacturing technique to precisely control the wire location and orientation. Incorporation of a volume fraction 25% of Al wires led to a 600% increase in elastic modulus and a 63% increase in tensile strength compared to pure PLA. These results indicate an efficient load transfer between the polymer matrix and the incorporated wires, despite exhibiting a relatively low interface strength. Overall, the novel strategy opens the possibility to manufacture high volume fraction composite laminates of thermoplastic polymers reinforced with metallic wires by material extrusion.

Comprehensive Review of Recent Advances in Nanoparticle-Based Corrosion Inhibition Approaches

Corrosion of metals is a persistent challenge in various industries, leading to significant economic losses and safety hazards. Conventional corrosion inhibitors often face limitations such as environmental toxicity, low efficiency, and short-term protection. Nanoparticle-based corrosion inhibitors have emerged as a promising alternative due to their unique properties and versatile applications. This paper provides a comprehensive review of the recent advances in nanoparticle-based corrosion inhibition strategies from 2015-2024 by harvesting data from secondary sources. The fundamental mechanisms underlying the corrosion inhibition by nanoparticles are discussed, including adsorption processes, passivation mechanisms, and synergistic effects with other inhibitors. Various types of nanoparticles, including metallic nanoparticles, metal oxide nanoparticles, polymer nanocomposites, carbon-based nanoparticles, and organic-inorganic hybrid nanoparticles, are explored for their corrosion inhibition potential. Furthermore, the applications of nanoparticle-based corrosion inhibitors in industries such as oil and gas, aerospace, automotive, marine, and infrastructure are highlighted. Despite significant progress, challenges such as stability, compatibility, and environmental concerns remain to be addressed. Future directions in nanoparticle-based corrosion inhibition research are also discussed, aiming to guide further developments in this promising field.

Achieving a High‐Strength Bonding between Aluminum Alloys and Polymer Composites via Self‐Riveting Welding

Great challenges exist in producing reliable welding between metals and polymer composites. In this study, self‐riveting welding (SRW) is employed to obtain metal–polymer hybrid joints with high load‐bearing capability. In this investigation, it is shown that the SRW joints with a prefabricated hole of 5.8 mm in diameter are characterized by fewer void defects with sufficient polymer filling, a tightly bonded joint interface, and a relatively uniform stress distribution along the joint interface during the tensile test, leading to the high load‐bearing capability of the SRW joints. The maximum average tensile force is 1.5 kN. The fracture occurs across the polymer composite rather than along the joint interface. In the results, it is shown that SRW has the potential to be developed into a method for fabricating reliable hybrid joints for the aerospace and automotive industries.

Study of the Electrical Properties and Characterization of a Metal‒Polymer Conductor Based on Silver-Containing Nanowires

Study of the Electrical Properties and Characterization of a Metal‒Polymer Conductor Based on Silver-Containing Nanowires

Effect of Process Parameters on the Appearance of Defects of Flake-Pigmented Metallic Polymer.

This study investigates the influence of the main process parameters of injection molding(mold temperature, melt temperature, and injection rate) on the appearance of defects of flake-pigmented metallic polymer parts. To understand the influence of process parameters, an appearance defects index (ADI) is proposed to quantify the appearance defects. In this process, we propose a criterion for judging the appearance of defects based on the results of fiber orientation and tensor distribution analyses of the skin layer, which is then verified analytically by simulating experiments from the literature. Using the Taguchi experimental method, we designed an L25 orthogonal array to systematically evaluate the influence of process parameters. For each experimental condition, the signal-to-noise ratio (S/N ratio) was calculated to determine the optimal level of each factor and its influence on the appearance of defects. According to the results, mold temperature has the greatest influence on the appearance of defects, with an influence of 48.7%, followed by injection rate with an influence of 40.8%, and melt temperature with an influence of 10.5%. The optimal process parameters were found to be a mold temperature of 40 °C, a melt temperature of 250 °C, and an injection rate of 10 cm3/s, which resulted in a 12.6% improvement in the Appearance defects index (ADI) compared to the standard injection molding condition of ABS materials. This study confirmed that it is possible to improve the appearance of defects by adjusting the process parameters of injection molding.

Charge Redistribution in High-Entropy Perovskite Oxide Porous Nanotubes Boosts Nitrate Electroreduction to Ammonia.

High-entropy perovskite oxides are promising materials in the field of electrocatalysis due to their advantages such as large spatial composition regulation, entropy effects, and tunable material properties. However, the preparation of high-entropy perovskite oxides with stable and controllable structures still remains challenging. Herein, we fabricated a series of high-entropy perovskite oxide porous nanotubes (PNTs) by electrospinning as efficient electrocatalysts for the nitrate reduction reaction (NO3RR). We further revealed that the different diffusion and decomposition behaviors of metal ions and polymers during the calcination process are the key to the formation of high-entropy perovskite oxide PNTs. Especially, LaSrNiCoMnFeCuO3 PNTs show excellent performance of the NO3RR, achieving the maximum NH3 Faradaic efficiency of almost 100%, yield rate of 1657.5 μg h-1 mgcat.-1, and durable stability after successive cycling, being one of the best electrocatalysts for the NO3RR. The mechanism studies show that the charge redistribution induced by the multisite synergistic effect and abundant unsaturated sites in the high-entropy perovskite oxide PNTs favors the adsorption of NO3- and key intermediates and reduces the catalytic energy barrier, thus further achieving high NO3- conversion efficiency.

Fabrication and application of wearable ionic polymer metal composite sensors for sports science

Ionic polymer-metal composite (IPMC) sensors were fabricated and investigated for quantifying impact energy in sports applications. Nafion membranes were roughened and electroless plated with gold-platinum electrodes to form IPMCs. When subjected to impacts of varying energies, the IPMCs generated transient voltage spikes whose peak amplitudes and slopes showed exponential relationships with the impact energies. Empirical models were developed correlating the IPMC voltage response features to the impact energies, achieving measurement accuracy within ±10 % RMS error over the tested dynamic range from 0.005 J to 1 J. The IPMC voltage profile was found to depend primarily on the impact energy and resultant strain rate, rather than impactor properties or contact geometry. Proper calibration procedures for each IPMC sensor before deployment were required to account for device-to-device variations. The results demonstrate the potential of IPMC sensors for continuous monitoring of athletes' impacts during sports activities. Further optimization is needed to improve the robustness, repeatability, and stability of the IPMC sensors under realistic sports conditions for reliable field performance.

Perspective on Lewis Acid-Base Interactions in Emerging Batteries.

Lewis acid-base interactions are common in chemical processes presented in diverse applications, such as synthesis, catalysis, batteries, semiconductors, and solar cells. The Lewis acid-base interactions allow precise tuning of material properties from the molecular level to more aggregated and organized structures. This review will focus on the origin, development, and prospects of applying Lewis acid-base interactions for the materials design and mechanism understanding in the advancement of battery materials and chemistries. The covered topics relate to aqueous batteries, lithium-ion batteries, solid-state batteries, alkali metal-sulfur batteries, and alkali metal-oxygen batteries. In this review, the Lewis acid-base theories will be first introduced. Thereafter the application strategies for Lewis acid-base interactions in solid-state and liquid-based batteries will be introduced from the aspects of liquid electrolyte, solid polymer electrolyte, metal anodes, and high-capacity cathodes. The underlying mechanism is highlighted in regard to ion transport, electrochemical stability, mechanical property, reaction kinetics, dendrite growth, corrosion, and so on. Last but not least, perspectives on the future directions related to Lewis acid-base interactions for next-generation batteries are like to be shared.

Selective metallization of polymer based on nanoscale tungsten oxide laser activators for advanced electronics

In recent years, laser-induced selective metallization (LISM) has been widely used to fabricate complex metal patterns and circuits due to its superior precision. Laser sensitizers known as laser-activated for electroless copper plating (ECP) are a significant premise in LISM. Herein, we confirmed that tungsten oxides (WO2.72, WO2.92, and WO3) exhibited excellent LISM activity due to oxygen vacancies (OVs) in their lattice. Moreover, non-stoichiometric tungsten (WO2.72, WO2.92) presented higher activity due to a higher concentration of OVs than the stoichiometric form of WO3, indicating the importance of OVs to the activity of laser sensitizers in LISM. Moreover, a higher OVs concentration in the laser sensitizer resulted in a higher LISM activity. This finding points out the direction for future laser sensitizer screening, synthesis, and development. After 30 min ECP, the square resistance of the prepared copper layer on ABS/WO2.72, ABS/WO2.92, and ABS/WO3 are 0.014, 0.035, and 0.176 Ω/sq, respectively. The nanoscale tungsten oxides with excellent LISM activity enabled the rapid fabrication of metal patterns and circuits in various scenarios, which expands the research field and application prospect of LISM technology. We demonstrate the advantages of LISM with tungsten oxides in fabricating advanced electronics. A strategy for replacing hand-wound windings in electromagnetic generators with 2D on-chip planar inductor arrays from LISM was proposed. The generated current reached a high level of 193 mA, and can be directly connected to wireless sensor networks to supply power. This work is the first research ever reporting laser sensitizers of tungsten oxides and introducing LISM technology into self-powered electronics.

Enhanced electromechanical performance of Nafion actuator doped by poly(ethylene glycol)‐grafted graphene oxide

AbstractCurrent ionic polymer–metal composite (IPMC) actuators have severe actuation drawbacks (i.e. low force output and poor stability), hampering their applications. To address these issues, poly(ethylene glycol)‐grafted graphene oxide (PEG‐GO) is synthesized and incorporated into a Nafion matrix, thus producing a PEG‐GO hybrid Nafion film with better physiochemical properties for fabricating a high‐performance, low‐cost IPMC actuator. The modification of PEG to GO not only prevents GO agglomeration and sedimentation, but also avoids loss of PEG in water. Driven by a 0.2 Hz, 2.5 V electric field, the hybrid IPMC actuator exhibits superior electromechanical behaviors, i.e. a swing angle of 110.3°, a blocking force of 6.89 mN and a stable working time of 485 s, respectively increasing by 92%, 209% and 294% when compared to a pure Nafion actuator. © 2024 Society of Chemical Industry.

Synthesis of bilaterally thiadiazole substituted vic-dioxime ligands and investigation of their polymeric metal complexes

In this study, three novels substituted 1,3,4-thiadiazole-derived vic-dioxime ligands and their corresponding polymeric transition metal (Co2+and Ni2+) complexes were synthesized and their structural characterizations were performed. For this purpose, 4,4′-bis(chloroacetyldiphenyl) ether (OKS1) was obtained from the reaction of diphenyl ether with chloroacetyl chloride at a 1:2 molar ratio with the help of the Friedel-Crafts reaction. Our first starting oxime compound “2,2′-(oxybis(4,1-phenylene))bis(N‑hydroxy-2-oxoacetimidoyl) chloride (OKS2)” was obtained from the reaction of OKS1 with butyl nitrite at a 1:2 molar ratio under the catalysis of HCl gas. Then, our final starting vic-dioxime compound “2,2′-(oxybis(4,1-phenylene))bis(N‑hydroxy-2-(hydroxyimino) acetimidoyl) chloride (OKS3)” was obtained from the reaction of OKS2 with hydroxylamine hydrochloride in ethanol media at 40 °C. Then, our three original target vic-dioxime compounds (OKL1-OKL3) were synthesized from the reaction of substituted 2-amino-1,3,4-thiadiazole compounds with OKS3. Structural characterizations of all synthesized organic compounds were made using elemental analysis, FTIR, 1H and 13C NMR and mass spectroscopy methods. Target complexes were obtained from the reaction of all ligands with MCl2.nH2O (M: Co2+and Ni2+) salts, and their structures were elucidated using FTIR, magnetic susceptibility, thermogravimetric analysis, elemental analysis, and ICP-OES spectroscopy methods.

Electrostatic Surface Charging by Water Dewetting.

Water dewetting generates static electricity. We reviewed historical experiments of this phenomenon, and we studied the charging of polymer slides and metal electrode supported polymer films withdrawn vertically from a pool of aqueous solutions. For pure water, charging was negative and surface charge densities increased with the speed of dewetting, which we explain by the thermally activated entrainment of nanometer-sized water droplets or clusters charged by unbalanced adsorbed electric double-layer ions. Surface charge densities increased for reduced polymer film thickness following a power law, which we explain by reduced discharge of the entrained water volumes. At low salinity c ≲ 10 μM, charging was proportional to electrokinetic interfacial charge densities: the negative charging was increased for alkaline solutions and for most salts at μM concentrations and the charge polarity was inversed to positive for a cationic surfactant, a salt with a highly positively charged cation, and for a strong acid at approximately pH 4. Charging was reduced again for c ≳ 100 μM, especially at high dewetting speeds and for chaotropic ions, which we explain by the entrainment of larger and more discharged droplets. We determined adsorption energies of the charged water clusters on the dewetted surface from thermally stimulated discharge of the charged polymer slides and we show that the surface charge distribution, imaged by charged toner powders and measured microscopically by Kelvin probe force microscopy, is a record of the dewetting process that provides spatial and kinetic information about the three-phase contact line motion.

Probing the microstructural properties of metal-reinforced polymer composites

Abstract Microstructural analysis is an important technique to study the extent of interaction between metal fillers and polymers. The aim of this study is to review the investigations on the microstructural properties of metal-reinforced polymer composites. Scanning Electron Microscope (SEM) operating at a magnification range of 2,500× is typically used for examining the microstructure of the composites. Microstructural analysis reveals two key qualitative informations, dispersion and interfacial adhesion. It was observed from the review that flaky metal fillers will maximise dispersion and interfacial adhesion hence leading to improved mechanical, tribological, electrical, and thermal properties of the composites. Utilizing ternary metallic components helps to eliminate aggregation because the cohesion of metal particles is limited. It is important that future microstructural studies evaluate nano-sized fillers as compared to micro-sized ones. Also, it is important to quantitatively correlate the arrangement of the fillers to macro-scale properties and finite element analysis is an important tool that can help achieving this.

Using fused filament fabrication to improve the tribocorrosion behaviour of 17-4 PH SS in comparison to other metal forming techniques

Fused filament fabrication (FFF) is one of the additive manufacturing processes which has gained more interest because of its simplicity and low-cost. This technology is similar to the conventional metal injection moulding (MIM) process, consisting of the feedstock preparation of metal powder and polymer binders, followed by layer-by-layer 3D printing (FFF) or injection (MIM) to create green parts and, finally, debinding and sintering. Moreover, both technologies provide near-dense parts. This work presents an in-depth study of the processing method’s influence. The porosity, microstructure, hardness, corrosion, and tribocorrosion behaviour are compared for 17-4 PH SS samples processed from powder by additive manufacturing using FFF and MIM, as well as conventional powder metallurgy (PM) samples. MIM samples exhibited the highest macro and microhardness, while corrosion behaviour was similar for both MIM and FFF samples, but superior in comparison to conventional PM samples. However, the FFF-as fabricated samples displayed a significant improvement in tribocorrosion resistance that could be explained by the higher proportion of delta ferrite and retained austenite in their microstructure.

Impact of gas flowrate on performance of chemiresistive NO2 sensors

This paper investigates in-depth the practical implications and the underlying mechanism of the effect of gas flowrate on the sensing performances of chemiresistive sensors. Three different types of 2D sensing layers were chosen for this study − metal oxide (ZnO, synthesized using hydrothermal method), organic polymer (tetrazine, synthesized using modified Pinner method), and transition metal dichalcogenide (WS2, synthesized using liquid exfoliation technique). The 2D morphologies of all the materials were confirmed using a field emission scanning electron microscope. These materials have different crystallographic structures, bandgaps, and functional groups. Yet, the response of all of them for 2–10 ppm NO2 was found to increase with increasing total flowrates when tested at 100, 500, and 1000 sccm. The response of ZnO varied from 6 to 46 %, 93 to 521 %, and 117 to 1416 %, while that of 2D tetrazine was found to vary from − 5.3 to − 13.9 %, −8.1 to − 26.5 %, and − 8.9 to − 34.2 %, and for WS2, the response ranged from 0 %, −0.8 to − 5.2 %, and − 2 to − 12.2 % for 2 – 10 ppm NO2 at 100, 500, and 1000 sccm flowrates, respectively. The response times and the recovery times of all the materials, too, exhibited the effect of gas flowrate.

Transparent electromagnetic interference shielding materials using MXene

AbstractWith the rapid advancement of terahertz technologies, electromagnetic interference (EMI) shielding materials are needed to ensure secure electromagnetic environments. Enormous efforts have been devoted to achieving highly efficient EMI shielding films by enhancing flexibility, lightweight, mechanical robustness, and high shielding efficiency. However, the consideration of the optical properties of these shielding materials is still in its infancy. By incorporating transparency, visual information from protected systems can be preserved for monitoring interior working conditions, and the optical imperceptibility allows nonoffensive and easy cover of shielding materials for both device and biology. There are many materials that can be applied to transparent EMI shields. In particular, two‐dimensional transition metal carbide/nitrides (MXenes), possessing the advantages of superior conductivity, optical properties, favorable flexibility, and facile processibility, have become a great candidate. This work reviews the recent research on developing highly efficient and optically transparent EMI shields in a comprehensive way. Materials from MXenes, indium tin oxide, metal, carbon, and conductive polymers are covered, with a focus on the employment of MXene‐based composites in transparent EMI shielding. The prospects and challenges for the future development of MXene‐based transparent EMI shields are discussed. This work aims to promote the development of high‐performance, optically transparent EMI shields for broader applications by leveraging MXenes.

Solid-State Electromechanical Smart Material Actuators for Pumps—A Review

Solid-state electromechanical smart material actuators are versatile as they permit diverse shapes and designs and can exhibit different actuation modes. An important advantage of these actuators compared to conventional ones is that they can be easily miniaturized to a sub-millimeter scale. In recent years, there has been a great surge in novel liquid pumps operated by these smart material actuators. These devices create opportunities for applications in fields ranging from aerospace and robotics to the biomedical and drug delivery industries. Although these have mainly been prototypes, a few products have already entered the market. To assist in the further development of this research track, we provide a taxonomy of the electromechanical smart material actuators available, and subsequently focus on the ones that have been utilized for operating pumps. The latter includes unidirectional shape memory alloy-, piezoelectric ceramic-, ferroelectric polymer-, dielectric elastomer-, ionic polymer metal composite- and conducting polymer-based actuators. Their properties are reviewed in the context of engineering pumps and summarized in comprehensive tables. Given the diverse requirements of pumps, these varied smart materials and their actuators offer exciting possibilities for designing and constructing devices for a wide array of applications.

Copper metallization of carbon fiber-reinforced epoxy polymer composites by surface activation and electrodeposition

The application of polymer metallization in lightweight and high-strength materials for the sporting goods, automotive, aerospace and construction sectors has attracted considerable attention. The present study aims to deposit a thin, uniform copper (Cu) layer on an epoxy‑carbon fiber (epoxy-Cf) composite material for lightweight, high-frequency radio reflector applications (Ka-Band and higher frequencies) required in space missions. In this work, a surface-activated electroplating technique in which the surface of the substrate is activated with a Sn/Ag system, followed by conventional electroplating is studied. Surface activation deposits layers of conducting metal ions on the surface of the epoxy-Cf composite, which significantly improves the electrical conductivity of the composite surface. The subsequent electrodeposition takes place from a CuSO4 solution with a pH value of 4 at three different current density values of 0.05 A/dm2, 0.5 A/dm2 and 1 A/dm2. The presence and abundance of metallic Cu over epoxy-Cf composite were confirmed by X-ray diffraction and X-ray photoelectron spectroscopy. The morphology and elemental composition of the coating were characterized by scanning electron microscopy equipped with energy dispersive spectroscopy. With current density and coating thickness, morphology of the deposit changed from cauliflower-like to spherical along with grain refinement. Microhardness test shows a hardness of 330 HV and the pull-off adhesion test gave a bond strength of 1.69 MPa for 27.56 μm thick copper deposit. A major challenge encountered during the deposition of Cu is the oxidation of the metal followed by immediate tarnishing. This issue has been effectively addressed by employing benzotriazole solution as a protective agent.