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Carbon nanomaterials, particularly carbon nanotubes (CNTs), are widely used as reinforcing fillers in rubber composites for advanced mechanical and electrical applications. However, the influence of rubber functionality and its interactions with CNTs remains underexplored. This study investigates electroactive elastomeric composites fabricated with CNTs in two common diene rubbers: natural rubber (NR) and acrylonitrile-butadiene rubber (NBR), each with distinct functionalities. For NR-based composites containing 2 vol% CNTs, mechanical properties, such as elastic modulus (2.24 MPa), tensile strength (12.48 MPa), and fracture toughness (26.92 MJ/m3), show significant improvements of 125%, 215%, and 164%, respectively, compared to unfilled rubber. Similarly, for NBR-based composites, the elastic modulus (5.46 MPa), tensile strength (13.47 MPa), and fracture toughness (82.89 MJ/m3) increase by 94%, 22%, and 65%, respectively, over the unfilled system. Although NBR-based composites exhibit higher mechanical properties, NR systems show more significant improvements, suggesting stronger chemical bonding between NR chains and CNTs, as evidenced by dynamic mechanical, X-ray diffraction, thermogravimetric, and thermodynamic analyses. The NBR-based composite at 1 vol% CNT content exhibits 261% higher piezoresistive strain sensitivity (GF = 65 at 0% ≤ Δε ≤ 200%) compared to the NR-based composite (GF = 18 at 0% ≤ Δε ≤ 200%). The highest gauge factor of 39,125 (1000% ≤ Δε ≤ 1220) was achieved in NBR-based composites with 1 vol% CNT content. However, 1.5 vol% CNT content in NBR provides better strain sensitivity and linearity than other composites. Additionally, NBR demonstrates superior electromechanical actuation properties, with 1317% higher actuation displacement and 276% higher electromechanical pressure compared to NR at an applied electric field of 12 kV. Due to the stronger chemical bonding between the rubber and CNT, NR-based composites are more suitable for dynamic mechanical applications. In contrast, NBR-based CNT composites are ideal for stretchable electromechanical sensors and actuators, owing to the high dielectric constant and polarizable functional groups in NBR. [ABSTRACT FROM AUTHOR]

This review article focuses on the potential of cobalt oxide composites with conducting polymers, particularly polypyrrole (PPy) and polyaniline (PANI), as advanced electrode materials for supercapacitors, batteries, and supercapatteries. Cobalt oxide, known for its high theoretical capacitance, is limited by poor conductivity and structural degradation during cycling. However, the integration of PPy and PANI has been proven to enhance the electrochemical performance through improved conductivity, increased pseudocapacitive effects, and enhanced structural integrity. This synergistic combination facilitates efficient charge transport and ion diffusion, resulting in improved cycling stability and energy storage capacity. Despite significant progress in synthesis techniques and composite design, challenges such as maintaining structural stability during prolonged cycling and scalability for mass production remain. This review highlights the synthesis methods, latest advancements, and electrochemical performance in cobalt oxide/PPy and cobalt oxide/PANI composites, emphasizing their potential to contribute to the development of next-generation energy storage devices. Further exploration into their application, especially in battery systems, is necessary to fully harness their capabilities and meet the increasing demands of energy storage technologies. [ABSTRACT FROM AUTHOR]

Wearable technology refers to the devices that are integrated with textiles, or implanted in the body or plants for smart monitoring. Hence, this wearable technology has attracted tremendous attention from researchers globally due to its smart functions to be useful for mankind. The key target of this review is to examine the potential of rubber composite materials for such wearable devices. The rubber composites reviewed explore silicone rubber as a rubber matrix (SR). Another objective includes the use of multi‐walled carbon nanotubes (MWCNTs) in pristine and functionalization forms explored as reinforcing fillers. Moreover, prospects of CNT including their structure, properties, and types are explored both in pristine and functionalized state are reviewed. Following this, the mechanical, and electrical, properties of such composites are reviewed. The reported results show that the reinforcing properties are strongly improved by adding functional groups to CNT in rubber composite. These improvements in reinforcing properties are assisted by the functional groups like carboxyl (OH), carbonyl (CO), epoxy, and alkoxy (CO) on the surface of filler are useful. They assist in improving the filler‐rubber compatibility thereby improving filler dispersion and thus finally mechanical and electrical properties. Following this, such improved properties are explored for specific real‐time wearable technologies. This real‐time monitoring includes nursing plant pulse growth monitoring, health monitoring, and humidity sensors. The review further proposes that the functionalized CNTs can be useful for obtaining robust real‐time strain‐sensing monitoring. Moreover, it assists in obtaining sharp response time, strain sensitivity, and good stretchability. Finally, the prospects and challenges are explored discussing the real‐time monitoring of these sensors. Highlights: Configurations for nursing plant growth and other monitoring parameters are reviewed.The properties of pristine and functionalized carbon nanotubes reinforced silicone rubber for wearable technology were reviewed.The mechanical, and electrical aspects of functionalized carbon nanotubes were comparatively reviewed.Applications such as wearable strain sensors, humidity sensors, and wearable plant pulse monitoring sensors were reported. [ABSTRACT FROM AUTHOR]

Multifunctional stretchable rubber composites are gaining attention due to their unique electrical, mechanical, and magnetic properties. However, their high production costs pose economic challenges. This study explores the use of cost-effective metal powders—iron, aluminum, and their 1:1 (vol/vol) hybrid filler—in styrene–butadiene rubber composites, varying from 10 to 20 vol%. The effects of these metal particles on the mechanical, electrical, morphological, and swelling properties were investigated. Metal particles generally act as non-reinforcing fillers but can significantly enhance the mechanical modulus, electrical, and magnetic properties based on the filler structure and the filler–rubber interactions. Iron-based composites exhibit significant electrical conductivity and excellent magnetic properties. Aluminum enhances the modulus, while the combination yields average mechanical properties with added magnetic characteristics. Iron demonstrates higher reactivity with sulfur-based crosslinking ingredients, adversely affecting the rubber matrix's crosslinks, as shown by swelling tests. This reactivity is attributed to iron's transition metal characteristics. At 20 vol%, iron-filled composites display the highest magnetic anisotropic effect on toughness (~25%) under a magnetic field by permanent magnets and excellent electrical conductivity (1.5 × 10−2 S/m). While iron significantly boosts the electrical and magnetic properties, higher filler amounts degrade the mechanical properties. These composites are currently suitable for electrical and smart mechanical applications, but incorporating reinforcing fillers could enhance their robustness for broader applications. [ABSTRACT FROM AUTHOR]

Energy harvesting systems fabricated from rubber composite materials are promising due to their ability to produce green energy with no environmental pollution. Thus, the present work investigated energy harvesting through piezoelectricity using rubber composites. These composites were fabricated by mixing titanium carbide (TiC) and molybdenum disulfide (MoS2) as reinforcing and electrically conductive fillers into a silicone rubber matrix. Excellent mechanical and electromechanical properties were produced by these composites. For example, the compressive modulus was 1.55 ± 0.08 MPa (control) and increased to 1.95 ± 0.07 MPa (6 phr or per hundred parts of rubber of TiC) and 2.02 ± 0.09 MPa (6 phr of MoS2). Similarly, the stretchability was 133 ± 7% (control) and increased to 153 ± 9% (6 phr of TiC) and 165 ± 12% (6 phr of MoS2). The reinforcing efficiency (R.E.) and reinforcing factor (R.F.) were also determined theoretically. These results agree well with those of the mechanical property tests and thus validate the experimental work. Finally, the electromechanical tests showed that at 30% strain, the output voltage was 3.5 mV (6 phr of TiC) and 6.7 mV (6 phr of MoS2). Overall, the results show that TiC and MoS2 added to silicone rubber lead to robust and versatile composite materials. These composite materials can be useful in achieving higher energy generation, high stretchability, and optimum stiffness and are in line with existing theoretical models. [ABSTRACT FROM AUTHOR]

This document discusses the advancements in functional rubber and elastomer composites. It begins by highlighting the innovations of mastication and vulcanization, which have greatly expanded the applications of rubber. The document then explores the development of synthetic rubbers and their various properties, as well as the use of elastomers in advanced technologies such as electronics and robotics. The importance of fillers in rubber composites is emphasized, along with the need for alternative or modified fillers. The document also provides an overview of published articles that focus on improving the properties of rubber composites through various techniques. It concludes by emphasizing the potential for further advancements in functional rubber and elastomeric materials and the need for continued research in this field. [Extracted from the article]

Vulcanization is a chemical modification of rubber that requires a considerable amount of thermal energy. To save thermal energy, the kinetics of rubber vulcanization should be improved. In this article, the curing properties of rubber vulcanization are thoroughly investigated using the moving die rheometer (MDR) technique. To enhance the kinetics in different stages of ZnO-based sulfur vulcanization systems, small amounts of MgO were added. The results revealed that the small amount of 1 to 2 phr (per hundred grams of rubber) of MgO in the controlled 5 phr ZnO-based curing systems can significantly improve the curing kinetics. For example, the optimum curing time of 1 phr MgO added to the 5 phr ZnO-containing semi-efficient vulcanization system at different temperatures was more than half that of the controlled 5 phr ZnO-only compound. While maintaining a similar rate of vulcanization, the vulcanization temperature can be reduced by up to 20 °C by using MgO as a co-cure activator, which exhibits similar or better rheometric mechanical properties compared to the controlled compounds. With the addition of MgO as a co-cure activator, the vulcanization reactions become very fast, enabling vulcanization to be completed, even at the boiling point of water (100 °C) with an affordable curing time (<1 h). By reducing the vulcanization temperature, the scorch safety time can be enhanced in the ZnO/MgO-based binary cure activator-containing vulcanizates. Overall, MgO could be a potential candidate as a co-cure activator with ZnO for the vulcanization of rubber, offering better economical and eco-friendly methods. [ABSTRACT FROM AUTHOR]

The contribution from specific interactions between rubber and filler sometimes plays a crucial role in the mechanical reinforcement and electromechanical sensitivities of rubber composites. This research explores the physical, mechanical, and electromechanical properties of styrene‐butadiene rubber (SBR) composites reinforced with carbon nanotubes (CNTs). Mechanical, thermodynamic, and scanning electron microscopy studies reveal that CNTs primarily enhance the mechanical properties through physical interactions with the rubber. Notably, π‐stacking interactions between the aromatic π‐electrons in SBR and the delocalized π‐electrons in CNTs contribute to significant improvements in mechanical strength. For instance, adding 4 phr (per hundred grams of rubber) of CNTs results in an impressive 871% increase in fracture toughness compared to unfilled rubber. These composites also exhibit remarkable stress and strain improvements even with small amounts of CNTs, making them suitable for robust strain sensing applications. Specifically, the composite containing 3 phr of CNTs demonstrates superior strain sensitivity (2.87 < GF < 48.62), a wide detection range (0% < Δε < 187%), and excellent linearity (0.927 < R2 < 0.995). Lower CNT content enhances sensitivities but reduces overall linearity, while higher CNT content improves linearity but decreases sensitivity. Moreover, these composites perform exceptionally well under compressive forces, even at a 0.5 N applied force. Given their excellent response to mechanical forces and strain, these composites hold promise for applications like electronic skin, strain sensors, and energy‐harvesting devices. Highlights: Carbon nanotubes (CNTs) were used as reinforcing fillers in SBR composites.CNTs significantly improve physical, mechanical, and electrical properties.Primarily, π‐stacking may be involved in enhancing these properties.The composites exhibit strong strain and force‐sensing capabilities.These composites could be valuable for wearable electronics in the future. [ABSTRACT FROM AUTHOR]

The different configurations of the composites originated with machine or human motion, and their mechanical stability for wearable electronics is in focus. Here, the study highlights that these configurations are critical for wearable devices. To achieve these aspects, the electroactive and dielectric silicone rubber (SR) was used as a host matrix. This SR not only provides flexibility, twisting, or stretchability for such devices, but its lightweight makes them comfortable for robust wearable devices. The reinforcing fillers such as graphite nanoplatelets (GNP) or diatomaceous earth (DE) and their hybrids are used. The electromechanical properties of the device were performed using the universal testing machine. The output voltage generated at 15 phr filler was 0.3 mV (GNP), 0.15 mV (DE), and 0.22 mV (hybrid). Similarly, the biomechanical properties were studied with human motion joints such as thumb pressing or wrist bending. The output voltage at 15 phr was best for thumb pressing and it was 0.42 mV (GNP), 0.18 mV (DE), and 0.25 mV (hybrid). In the same way, the mechanical aspects studied in this work are compressive modulus, tensile strength, and fracture strain. For example, the compressive modulus was 1.28 MPa (control) and increased at 15 phr filler to 2.44 MPa (GNP), 3.2 MPa (DE), and 2.75 MPa (hybrid). Similarly, the mechanical stretchability of the devices was 134% (control) and changed at 15 phr filler to 128% (GNP), 78% (DE), and 109% (hybrid). Overall, the work demonstrates the method to develop a device with high mechanical, electromechanical, and biomechanical properties and their usefulness for wearable electronic devices. [ABSTRACT FROM AUTHOR]

Mechanical robustness and high energy efficiency of composite materials are immensely important in modern stretchable, self-powered electronic devices. However, the availability of these materials and their toxicities are challenging factors. This paper presents the mechanical and energy-harvesting performances of low-cost natural rubber composites made of stearic acid-modified diatomaceous earth (mDE) and carbon nanotubes (CNTs). The obtained mechanical properties were significantly better than those of unfilled rubber. Compared to pristine diatomaceous earth, mDE has higher reinforcing efficiencies in terms of mechanical properties because of the effective chemical surface modification by stearic acid and enhanced filler–rubber interactions. The addition of a small amount of CNT as a component in the hybrid filler systems not only improves the mechanical properties but also improves the electrical properties of the rubber composites and has electromechanical sensitivity. For example, the fracture toughness of unfilled rubber (9.74 MJ/m3) can be enhanced by approximately 484% in a composite (56.86 MJ/m3) with 40 phr (per hundred grams of rubber) hybrid filler, whereas the composite showed electrical conductivity. At a similar mechanical load, the energy-harvesting efficiency of the composite containing 57 phr mDE and 3 phr CNT hybrid filler was nearly double that of the only 3 phr CNT-containing composite. The higher energy-harvesting efficiency of the mDE-filled conductive composites may be due to their increased dielectric behaviour. Because of their bio-based materials, rubber composites made by mDE can be considered eco-friendly composites for mechanical and energy harvesting applications and suitable electronic health monitoring devices. [ABSTRACT FROM AUTHOR]

Electro-mechanical configurations can be piezo-electric transducers, triboelectric generators, electromagnetic induction, or hybrid systems. Our present study aims at developing energy generation through the piezoelectric principle. Gel-type soft SR with Shore A hardness below 30 was used as a versatile material for an elastomeric substrate. Also, multi-wall carbon nanotube (MWCNT), and diatomaceous earth (DE) were used as reinforcing fillers. This "gel-type" soft SR has crosslinking polymer networks with silicone encapsulated within its structure. Mechanical properties such as modulus or stretchability are of utmost importance for such devices based on "gel-type" soft. From the experiments, some of the mechanical aspect's values are summarized. For example, the stretchability was 99% (control) and changes to 127% (3 phr, MWCNT), 76% (20 phr DE), and 103% (20 phr hybrid). From electro-mechanical tests, the output voltage was 0.21 mV (control) and changed to 0.26 mV (3 phr, MWCNT), 0.19 mV (20 phr DE), and 0.29 mV (20 phr hybrid). Moreover, from real-time biomechanical human motion tests in "gel-type" soft-based composites, a relationship among output voltage from machine to human motions was established. Overall, these configurations make them promising against traditional portable devices such as batteries for small power applications such as mobile phones. [ABSTRACT FROM AUTHOR]

Recently, the advances in stretchable electronic devices have attracted great attention around the world. New technologies are constantly updated to obtain a stretchable device with high performance and robust durability. The stretchable device‐based rubber composites were prepared with the addition of room‐temperature‐vulcanized silicone rubber (RTV‐SR) and different types of nanofillers such as graphite nanoplatelets (GNP), molybdenum disulfide (MoS2), and their hybrid. The hybrid composites contain both nanofillers in 50:50 ratios. The mechanical performance of the stretchable device was studied and presented. For example, the compressive modulus was 1.86 MPa (virgin), and at 20 per hundred parts of rubber (phr) was 3.9 MPa (GNP), 2.3 MPa (MoS2), and 2.72 MPa (Hybrid). The mechanical stretching ability of the composites was 120% (virgin), and at 20 phr was 170% (GNP), 182% (MoS2), and 171% for (Hybrid). At end of the work, a novel stretchable device based on a piezo‐electric effect is presented which provides an output voltage of ~1.2 V and high durability of >0.1 million cycles without significant degradation. This device is based on a rubber composite with the inclusion of electro‐active and dielectric materials as described in the subsequent section of the paper. [ABSTRACT FROM AUTHOR]

The demand for multi-functional elastomers is increasing, as they offer a range of desirable properties such as reinforcement, mechanical stretchability, magnetic sensitivity, strain sensing, and energy harvesting capabilities. The excellent durability of these composites is the key factor behind their promising multi-functionality. In this study, various composites based on multi-wall carbon nanotubes (MWCNT), clay minerals (MT-Clay), electrolyte iron particles (EIP), and their hybrids were used to fabricate these devices using silicone rubber as the elastomeric matrix. The mechanical performance of these composites was evaluated, with their compressive moduli, which was found to be 1.73 MPa for the control sample, 3.9 MPa for MWCNT composites at 3 per hundred parts of rubber (phr), 2.2 MPa for MT-Clay composites (8 phr), 3.2 MPa for EIP composites (80 phr), and 4.1 MPa for hybrid composites (80 phr). After evaluating the mechanical performance, the composites were assessed for industrial use based on their improved properties. The deviation from their experimental performance was studied using various theoretical models such as the Guth–Gold Smallwood model and the Halpin–Tsai model. Finally, a piezo-electric energy harvesting device was fabricated using the aforementioned composites, and their output voltages were measured. The MWCNT composites showed the highest output voltage of approximately 2 milli-volt (mV), indicating their potential for this application. Lastly, magnetic sensitivity and stress relaxation tests were performed on the hybrid and EIP composites, with the hybrid composite demonstrating better magnetic sensitivity and stress relaxation. Overall, this study provides guidance on achieving promising mechanical properties in such materials and their suitability for various applications, such as energy harvesting and magnetic sensitivity. [ABSTRACT FROM AUTHOR]

Recently, hybrid fillers have been found to be more advantageous in energy-harvesting composites. This study investigated the mechanical and electromechanical performances of silicone rubber-based composites made from hybrid fillers containing conductive nanocarbon black (NCB) and molybdenum disulfide (MoS2). A hybrid filler system containing only 3 phr (per hundred grams of rubber) MoS2 and 17 phr NCB provided higher fracture strain, better tensile strength, and excellent toughness values compared to the 20 phr NCB-only-filled and 5 phr MoS2-only-filled rubber composites. The chemical cross-link densities suggest that NCB promoted the formation of cross-links, whereas MoS2 slightly reduced the cross-link density. The higher mechanical properties in the hybrid filler systems suggest that the filler particles were more uniformly distributed, which was confirmed by the scanning electron microscope study. Uniformly distributed filler particles with moderate cross-link density in hybrid filler systems greatly improved the fracture strain and fracture toughness. For example, the hybrid filler with a 17:3 ratio of NCB to MoS2 showed a 184% increment in fracture toughness, and a 93% increment in fracture strain, compared to the 20 phr NCB-only-filled composite. Regarding electromechanical sensing with 2 kPa of applied cyclic pressure, the hybrid filler (17:3 CB to MoS2) performed significantly better (~100%) than the 20 phr NCB-only compound. This may have been due to the excellent distribution of conducting NCB networks and piezoelectric MoS2 that caused symmetric charging–discharging in the toughened hybrid composite. Thus, hybrid composites with excellent fatigue resistance can find dynamic applications, such as in blood pressure measurement. [ABSTRACT FROM AUTHOR]

Zinc oxide performs as the best cure activator in sulfur-based vulcanization of rubber, but it is regarded as a highly toxic material for aquatic organisms. Hence, the toxic cure activator should be replaced by a non-toxic one. Still, there is no suitable alternative industrially. However, binary activators combining ZnO and another metal oxide such as MgO can largely reduce the level of ZnO with some improved benefits in the vulcanization of rubber as investigated in this research. Curing, mechanical, and thermal characteristics were investigated to find out the suitability of MgO in the vulcanization of rubber. Curing studies reveal that significant reductions in the optimum curing times are found by using MgO as a co-cure activator. Especially, the rate of vulcanization with conventional 5 phr (per hundred grams) ZnO can be enhanced by more than double, going from 0.3 Nm/min to 0.85 Nm/min by the use of a 3:2 ratio of MgO to ZnO cure activator system that should have high industrial importance. Mechanical and thermal properties investigations suggest that MgO as a co-cure activator used at 60% can provide 7.5% higher M100 (modulus at 100% strain) (0.58 MPa from 0.54 MPa), 20% higher tensile strength (23.7 MPa from 19.5 MPa), 15% higher elongation at break (1455% from 1270%), 68% higher fracture toughness (126 MJ/m3 from 75 MJ/m3), and comparable thermal stability than conventionally using 100 % ZnO. Especially, MgO as a co-cure activator could be very useful for improving the fracture toughness in rubber compounds compared to ZnO as a single-site curing activator. The significant improvements in the curing and mechanical properties suggest that MgO and ZnO undergo chemical interactions during vulcanization. Such rubber compounds can be useful in advanced tough and stretchable applications. [ABSTRACT FROM AUTHOR]

New and soft composites with good mechanical stretchability are constantly addressed in the literature due to their use in various industrial applications such as soft robotics. The stretchable magnetic materials presented in this work show a promising magnetic effect of up to 28% and improved magnetic sensitivity. The composites are soft in nature and possess hardness below 65. These composites were prepared by mixing silicone rubber with fillers such as graphene nanoplatelets (GNP), electrolyte-iron particles (EIP), and their hybrid via solution mixing. The final composites were cured at room temperature for 24 h and their isotropic and anisotropic properties were studied and presented. The mechanical properties under compressive and tensile strain were studied in detail. The results show that the compressive modulus was 1.73 MPa (control) and increased to 3.7 MPa (GNP) at 15 per hundred parts of rubber (phr), 3.2 MPa (EIP), and 4.3 MPa (hybrid) at 80 phr. Similarly, the mechanical stretchability was 112% (control) and increased to 186% (GNP) at 15 phr, 134% (EIP), and 136% (hybrid) at 60 phr. Thus, GNP emerges as a superior reinforcing filler with high stiffness, a high compressive modulus, and high mechanical stretchability. However, the GNP did not show mechanical sensitivity under a magnetic field. Therefore, the hybrids containing GNP and EIP were considered and an improved mechanical performance with magnetic sensitivity was noticed and reported. The mechanism involves the orientation of EIP under a magnetic field causing a magnetic effect, which is 28% for EIP and 5% for hybrid. [ABSTRACT FROM AUTHOR]

Recently, polymer composite based stretchable piezo‐electric energy harvesting device have attracted a great attention in composite industry. At laboratory scale, these piezo‐electric devices have ability to generate impressive voltage (~8 V) with high durability (>0.5 million cycles) depending upon nature of the material used in electrode and substrate. In this work, composites were prepared by mixing room temperature vulcanized silicone rubber (RTV‐SR) and nanofillers such as multi‐wall carbon nanotube (MWCNT), nano‐carbon black (nano‐CB), graphite nanoplatelets (GNP), in single or hybrid with molybdenum disulfide (MoS2). These fillers differentiate on basis of their structure ranging from 0‐dimensional (0‐D) to 3‐D. The effects of these structures on mechanical properties are demonstrated. Among them, MWCNT with 1‐D, tube shape morphology, high aspect ratio of 65 shows dominating mechanical properties even at 2 per hundred parts of rubber (phr) loading followed by nano‐CB, GNP at 8 phr and MoS2 at 2 phr. A synergistic effect in mechanical properties between hybrid fillers such as tensile strength and fracture strain was demonstrated. In the end, the composites were tested for piezo‐electric energy generation and durability cycles for the best candidate such as MWCNT was tested for up to 0.5 million cycles was demonstrated. [ABSTRACT FROM AUTHOR]

In this study, we developed a combination accelerator system to synergistically improve the vulcanizing activity of 2-marcapto benzothiazole (MBT) with different nitrosamine-safe thiuram disulfides (TDs), namely, bis-(N-benzyl piperazino) thiuram disulfide (BPTD), bis-(N-phenyl piperazino) thiuram disulfide (PPTD), and bis-(N-ethyl piperazino) thiuram disulfide (EPTD), which can be used as nitrosamine-safe cross-linking accelerators for sulfur based rubber vulcanization. The results were compared with that of a conventionally unsafe TD, tetramethyl thiuram disulfide (TMTD) combined with MBT, to evaluate the efficiencies of these nitrosamine-safe TD accelerators for industrial applications. The curing and mechanical properties of rubber vulcanization were investigated to understand the synergism between MBT and nitrosoamine-safe TDs. The results indicate that novel TDs combined with MBT significantly improve the curing characteristics and mechanical properties following to the TDs with smaller molecular size and higher basicity. The MBT/BPTD system had higher modulus values because BPTD has a higher molar mass, which facilitates a better distribution of accelerators in the rubber matrix. Overall, the MBT/EPTD accelerator systems with equal molar ratios can compete with the curing rates, tensile strengths, and moduli of unsafe TMTD accelerator systems in the vulcanization of rubber. [ABSTRACT FROM AUTHOR]

New technologies are constantly addressed in the scientific community for updating novel stretchable devices, such as flexible electronics, electronic packaging, and piezo-electric energy-harvesting devices. The device promoted in the present work was found to generate promising ~6V and durability of >0.4 million cycles. This stretchable device was based on rubber composites. These rubber composites were developed by solution mixing of room temperature silicone rubber (RTV-SR) and nanofiller, such as multi-wall carbon nanotube (MWCNT) and micron-sized copper particles and their hybrid. The hybrid composite consists of 50:50 of both fillers. The mechanical stretchability and compressive modulus of the composites were studied in detail. For example, the compressive modulus was 1.82 MPa (virgin) and increased at 3 per hundred parts of rubber (phr) to 3.75 MPa (MWCNT), 2.2 MPa (copper particles) and 2.75 MPa (hybrid). Similarly, the stretching ability for the composites used in fabricating devices was 148% (virgin) and changes at 3 phr to 144% (MWCNT), 230% (copper particles) and 199% (hybrid). Hence, the hybrid composite was found suitable with optimum stiffness and robust stretching ability to be useful for stretching electronic devices explored in this work. These improved properties were tested for a real-time stretchable device, such as a piezoelectric energy-harvesting device and their improved voltage output and durability were reported. In the end, a series of experiments conducted were summarized and a discussion on the best candidate with higher properties useful for prospective applications was reported. [ABSTRACT FROM AUTHOR]

The 6th element of the periodic table is undoubtedly one of the most incredible aspects of creation. Graphene has a 2-D sheet structure comprised of strong covalent bonds between sp2 hybridized carbon atoms and has attracted much research interest because of its unique physicochemical properties. However, the controlled syntheses of mono-layered and few-layered graphene remain topics of research concern. In the present work, chemically reduced graphene oxide (CRGO) was synthesized by 'top-down' using the modified Hummers' method. CRGO and room-temperature-vulcanized silicone rubber (RTV-SR) were mixed to prepare composites with different CRGO loadings. We found that as little as 2 per hundred parts of rubber [phr] CRGO in RTV-SR transformed the normally rigid RTV-SR into a soft composite with a hardness decrease to 15. Moreover, the compressive modulus falls to 0.6 MPa. However, the dissipation losses decrease at 2 phr CRGO, which is a good property. For tensile mechanical properties, the fracture strain increases to 100% while tensile strength falls sharply to 0.1 MPa. Moreover, the electrical conductivity increases as the amount of CRGO increases. So, composite with soft nature and higher electrical properties are useful for various applications such as soft robotics or soft piezoelectric energy harvesting. In this work, the piezoelectric energy harvesting was performed by monitoring the output voltages generated. Output voltages were stable for RTV-SR but increased with increasing cycle number for RTV-SR/CRGO-based composites. This study provides insights into the use of soft RTV-SR/CRGO composites for soft robotics, actuation, energy harvesting, and vehicle applications. [ABSTRACT FROM AUTHOR]

Graphite nanoplatelet (GNP) flakes have attracted attention for the production of polymeric nanocomposites owing to their excellent mechanical, thermal, and electrical properties. In this work, the impact of three grades of GNP flakes with different surface area on the properties of room‐temperature vulcanized silicone rubber (RTV‐SR) nanocomposites was analyzed. The surface area was determined by the Brunauer–Emmett–Teller (BET) method using N2 adsorption isotherms. The BET analysis showed that the GNP grades had BET surface areas of 422, 295, and 123 m2/g. Nanocomposites based on the three grades of GNP flakes with different surface area and RTV‐SR were prepared using the solution‐casting process. Mechanical analysis of the samples showed that the compressive modulus increased from 3.8 MPa (0 phr) to 4.4, 4.34, and 5.26 MPa at the filler loading of 15 phr of GNPs with 422, 295, and 123 m2/g, respectively. In addition, the fracture strain of the nanocomposites increased from 116% (0 phr) to 228%, 198%, and 151% in the samples with 422, 295, and 123 m2/g, respectively, at the filler loading of 15 phr GNP. [ABSTRACT FROM AUTHOR]

Simultaneously exhibiting both a magnetic response and piezoelectric energy harvesting in magneto-rheological elastomers (MREs) is a win–win situation in a soft (hardness below 65) composite-based device. In the present work, composites based on iron oxide (Fe2O3) were prepared and exhibited a magnetic response; other composites based on the electrically conductive reinforcing nanofiller, graphite nanoplatelets (GNP), were also prepared and exhibited energy generation. A piezoelectric energy-harvesting device based on composites exhibited an impressive voltage of ~10 V and demonstrated a high durability of 0.5 million cycles. These nanofillers were added in room temperature vulcanized silicone rubber (RTV-SR) and their magnetic response and piezoelectric energy generation were studied both in single and hybrid form. The hybrid composite consisted of 10 per hundred parts of rubber (phr) of Fe2O3 and 10 phr of GNP. The experimental data show that the compressive modulus of the composites was 1.71 MPa (virgin), 2.73 (GNP), 2.65 MPa (Fe2O3), and 3.54 MPa (hybrid). Similarly, the fracture strain of the composites was 89% (virgin), 109% (GNP), 105% (Fe2O3), 133% (hybrid). Moreover, cyclic multi-hysteresis tests show that the hybrid composites exhibiting higher mechanical properties had the shortcoming of showing higher dissipation losses. In the end, this work demonstrates a rubber composite that provides an energy-harvesting device with an impressive voltage, high durability, and MREs with high magnetic sensitivity. [ABSTRACT FROM AUTHOR]