Thermal Properties Of Materials Research Articles

Investigating thermal properties of 2D non-layered material using a NEMS-based 2-DOF approach towards ultrahigh-performance bolometer

ABSTRACT Two-dimensional (2D) non-layered materials in many aspects differ from their layered counterparts, and the exploration of their physical properties has produced many intriguing findings. However, due to challenges in applying existing experimental techniques to such nanoscale samples, their thermal properties have remained largely uncharacterized, hindering further exploration and device application using this promising material system. Here, we demonstrate an experimental study of thermal conduction in β-In2S3, a typical non-layered 2D material, using a resonant nanoelectromechanical systems (NEMS) platform. We devise a new two-degrees-of-freedom technique, more responsive and sensitive than Raman spectroscopy, to simultaneously determine both the thermal conductivity to be 3.7 W m−1 K−1 and its interfacial thermal conductance with SiO2 as 6.4 MW m−2 K−1. Leveraging such unique thermal properties, we further demonstrate a record-high power-to-frequency responsivity of −447 ppm/μW in β-In2S3 NEMS sensors, the best among drumhead NEMS-based bolometers. Our findings offer an effective approach for studying thermal properties and exploring potential thermal applications of 2D non-layered materials.

Preparation, electronic structure and thermal properties of Zn-doped LaMgAl11O19 materials

LaMgAl11O19 (LMA) with magnetoplumbite structure is a promising thermal barrier material due to its excellent thermal properties. In this work, Zn-doped LMA materials were studied in order to improve the thermal performance, and LaZnxMg1-xAl11O19 (x = 0, 0.1, 0.3, 0.5, 0.7, 1.0) were prepared by sol-gel method. The as-synthesized powder materials possess pure LMA phase and show the morphology of hexagonal plates. X-ray photoelectron spectroscopy result shows that there are AlO4 tetrahedra and AlO6 octahedra units in the target materials, and Zn2+ ions replace Mg2+ ions to occupy the tetrahedral position of magnetoplumbite structure. The composition LaZn0.3Mg0.7Al11O19 material exhibits the lowest thermal conductivity of 0.38 W/(m·K) at 1000oC while maintaining a high coefficient of thermal expansion (10.86 × 10−6 K−1). Therefore, the thermal properties of LMA materials can be improved by adding an appropriate amount of Zn ions.

Graphene nanoribbon hydrogel scaffold for highly conductive and robust polyimide nanocomposite

Although highly loaded graphitic nanocarbon materials effectively enhance the electrical, mechanical, and thermal properties of polymeric materials, their practical implementation has been hindered by severe aggregation issues. Here, we propose a method to achieve homogeneous nanocarbon-polyimide (PI) composites by integrating graphene oxide nanoribbons (GONRs) with polyamic acid ammonium (PAA) salt, a precursor of PI. Self-assembled scaffold structure of GONRs hydrogel enables the uniform integration and immobilization of PAA within the GONR scaffold, mitigating aggregation concerns. The resulting GONR/PAA hydrogel, formed through physical interactions, can be coated onto substrates via a shear stress-induced bar coating method due to its viscoelastic rheological properties. Subsequent heat treatment at 400 °C triggers the imidization reaction of PAA and the reduction of GONR, facilitating the formation of uniformly integrated GNR/PI nanocomposite coatings. Under optimized conditions, incorporating a high-loading GONR content in PAA (95 wt% of GONR and 5 wt% of PAA) yielded GNR/PI composites with excellent mechanical properties, exhibiting a hardness of 0.75 GPa and an elastic modulus of 8.3 GPa. Additionally, this GNR/PI composite displayed a good electrical conductivity of 3890 S/m, attributed to the electrical pathways formed by GNRs within the PI matrix.

Thermal Properties of Athermal Granular Materials.

Dry granular materials consist of a vast ensemble of discrete solid particles interacting through complex frictional forces at the contact points. The particles are so large that these systems are believed to be completely athermal. Here, we arrest the dynamics of a flowing granular material in a steady-state-flow configuration, enabling an isolated examination of aging at the particle contacts without granular rearrangements. Our findings reveal that the evolution of interparticle forces within the arrested athermal granular network results in the spontaneous increase of the system's yield stress. This strengthening process is logarithmic in time with a rate that depends on the temperature. We demonstrate that the material's stress relaxation exhibits similar time- and temperature-dependent behavior, suggesting a shared origin for aging and stress relaxation in these systems governed by thermal molecular processes at the scale of the grain contacts.

Analysis of the Impact of Waste Fly Ash on Changes in the Structure and Thermal Properties of the Produced Recycled Materials Based on Polyethylene.

This paper presents the results of the research on the structure and thermal properties of materials made from fly ash based on high-density polyethylene (HDPE). Composites based on a polyethylene matrix with 5, 10, and 15 wt% fly ash from hard coal combustion content were examined. Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) was used to identify characteristic functional groups present in the chemical structure of polyethylene and the composites based on its matrix. Structural analysis was performed using X-ray diffraction (XRD), a differential scanning calorimeter (DSC), and microscopic examinations. Mechanical properties were also examined. Analysis of the thermal effect values determined by the DSC technique, XRD, and FTIR-ATR allowed the evaluation of the crystallinity of the tested materials. Polyethylene is generally considered to be a two-phase system consisting of crystalline and amorphous regions and is a plastic characterized by a significant crystalline phase content. Based on the FTIR-ATR spectra, DSC curves, and XRD, the effect of the filler and the changes occurring in the materials studied resulted in a decrease in the degree of crystallinity and a change in the melting point and crystallization temperature of the polymer matrix were established. Microscopic examinations were carried out to analyze the microstructure of the composites to collect information on the distribution and shape of the filler particles, indicating their size and distribution in the polymer matrix. Furthermore, the use of scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDS) allowed for the microanalysis of the chemical composition of the filler particles.

Recycling and reuse of waste banded iron formation as fine aggregate in the production of lightweight foamed concrete: Fresh-state, mechanical, thermal, microstructure and durability properties assessment

This study investigates the possibility of using BIFs as sustainable fine aggregates to produce lightweight foam concrete (LWFC) by replacing sand with 5, 10, 15, 20, and 25 % banded iron formations (BIFs). The fresh concrete properties, such as slump flow, density, and setting time, as well as its mechanical properties, including compressive strength, splitting strength, and flexural strength, were investigated. The thermal conductivity, specific heat, porosity, gas permeability, pore distribution, and sorptivity were measured to determine durability and thermal performance. Microstructural analysis of the mixes was performed using SEM, energy-dispersive X-ray spectroscopy (EDX), and mapping. The results recommended a 10 % replacement ratio to achieve an increased compressive strength ratio of 55.88 % compared to the control mix at 7 days (d). The strength at later ages increased compared to that of the control mix by 33.9 %, 30 %, 42.48 %, and 42.4 % at 14, 28, 56, and 180 d, respectively. In addition, the flexure increased by 42.7 % at 7 d, 49.6 % at 14 d, and 45.6 % at 28 d compared to the control mix. In addition, the UPV also increased gradually from 2757 to 3699 km/s with increase in BIFs content. Furthermore, the porosity decreased at 7 d, 14 d, 28 d, and 90 d. Moreover, chloride penetration decreased by 2.5 %, where an improvement in thermal conductivity was achieved with BIFs to 0.342 W/mK compared to that of the control mix. In addition, a reduction in the specific heat of the material from 1042 J/kg K to 1007 J/kg K was observed. SEM showed a better arrangement of pores when BIFs were utilized compared with that of control mix without BIFs. In conclusion, the incorporation of waste BIFs as fine aggregates in lightweight foam concrete demonstrates a promising potential for enhancing the mechanical and thermal properties of construction materials, paving the way for durable building materials in the construction industry.

Synergy of Hybrid Fillers for Emerging Composite and Nanocomposite Materials-A Review.

Nanocomposites with polymer matrix provide tremendous opportunities to investigate new functions beyond those of traditional materials. The global community is gradually tending toward the use of composite and nanocomposite materials. This review is aimed at reporting the recent developments and understanding revolving around hybridizing fillers for composite materials. The influence of various analyses, characterizations, and mechanical properties of the hybrid filler are considered. The introduction of hybrid fillers to polymer matrices enhances the macro and micro properties of the composites and nanocomposites resulting from the synergistic interactions between the hybrid fillers and the polymers. In this review, the synergistic impact of using hybrid fillers in the production of developing composite and nanocomposite materials is highlighted. The use of hybrid fillers offers a viable way to improve the mechanical, thermal, and electrical properties of these sophisticated materials. This study explains the many tactics and methodologies used to install hybrid fillers into composite and nanocomposite matrices by conducting a thorough analysis of recent research. Furthermore, the synergistic interactions of several types of fillers, including organic-inorganic, nano-micro, and bio-based fillers, are fully investigated. The performance benefits obtained from the synergistic combination of various fillers are examined, as well as their prospective applications in a variety of disciplines. Furthermore, the difficulties and opportunities related to the use of hybrid fillers are critically reviewed, presenting perspectives on future research paths in this rapidly expanding area of materials science.

The Effect of Expanded Graphite Content on the Thermal Properties of Fatty Acid Composite Materials for Thermal Energy Storage.

The mass content of expanded graphite (EG) in fatty acid/expanded graphite composite phase-change materials (CPCMs) affects their thermal properties. In this study, a series of capric-myristic acid/expanded graphite CPCMs with different EG mass content (1%, 3%, 5%, 8%, 12%, 16%, and 20%) were prepared. The adsorption performance effect of EG on the PCMs was observed and analyzed. The structure and thermal properties of the prepared CPCMs were characterized via scanning electron microscopy, differential scanning calorimetry, thermal conductivity measurements, and heat energy storage/release experiments. The results show that the minimum mass content of EG in the CPCMs is 7.6%. The phase-change temperature of the CPCMs is close to that of the PCMs, at around 19 °C. The latent heat of phase change is equivalent to that of the PCM at the corresponding mass content, and that of phase change with an EG mass content of 8% is 138.0 J/g. The CPCMs exhibit a large increase in thermal conductivity and a significant decrease in storage/release time as the expanded graphite mass content increases. The thermal conductivity of the CPCM with a mass content of 20% is 418.5% higher than that with a mass content of 5%. With an increase in the EG mass content in CPCMs, the heat transfer mainly transitions from phase-change heat transfer to thermal conductivity.

Comparative Study of Natural Fibres to Improve Insulation in Wooden Beehives Using Sensor Networks

The beekeeping sector is increasingly focused on creating optimal and natural environments for honeybees to reduce dependence on external factors, especially given progressively hotter summers. Improving hive thermal conditions can enhance bee wellbeing and production. While pinewood hives are predominant, some have started using insulating materials like polystyrene. However, many synthetic materials, despite their excellent insulation properties, are incompatible with organic food production, requiring alternative solutions. This study compares the thermal insulation properties of various natural materials, including white and black agglomerated cork, wood fibres, and rock mineral wool. These materials are potentially compatible with organic food production. Additionally, the research evaluates cost-effective sensor networks to monitor bioclimatic variables in real time. Lab tests using a Langstroth-type hive with a controlled heat source were conducted, monitoring temperature and humidity inside and outside the hive. The results revealed that all selected materials provided similar thermal insulation, superior to a hive without insulation. This finding suggests that using natural materials can enhance hive thermal comfort (i.e., the material’s ability to maintain a stable internal temperature), thereby improving honeybee wellbeing and productivity in a manner compatible with organic food production.

Bio-based modification of polyhydroxyalkanoates (PHA) towards increased antimicrobial activities and reduced cytotoxicity

With the increased occurrence of bacteria resistance to conventional antibiotics, the development of novel antimicrobials is urgently needed. Traditional biomaterials used for delivering these agents often struggle to achieve sustained release while maintaining non-cytotoxic properties. In this study, we present an innovative approach using bacterial polyhydroxyalkanoates (PHA) as a carrier for antimicrobial delivery, specifically designed for wound healing applications. Octenidine dihydrochloride (OCT), a widely used antimicrobial agent, served as our model drug. To achieve the desired balance of OCT release and low cytotoxicity, we introduced a novel bio-derived additive, 3-hydroxy-pentadecanoic acid (3OHC15), extracted from bacteria. This additive significantly improved the hydrophilicity of PHA films, resulting in enhanced and sustained release of OCT. Importantly, the additive did not adversely affect the material's tensile strength or thermal properties. The increased OCT release led to improved antibacterial activity against both Gram-negative and -positive strains. Most notably, the incorporation of 3OHC15 in PHA mitigated the cytotoxic effects of the released drug on human fibroblasts, ensuring biocompatibility. This work represents a novel strategy in the design of biomaterials for the delivery of bioactive compounds, achieving a critical balance between efficacy and cytocompatibility, and marks a significant advancement in the field of antimicrobial delivery systems.

Analyzing the thermal performance of walling systems in low-income housing through computational fluid dynamics approach

The thermal properties of wall materials have a direct impact on the thermal performance of the indoor environment, by also influencing the occupant’s well-being. Coupled with airflow dynamics, the thermal performance of wall materials influences the indoor air temperature distribution thereby impacting thermal comfort, particularly in naturally ventilated (NV) spaces. However, defining the relationships between the wall characteristics, airflow dynamics, and thermal comfort for selecting the appropriate wall material for low-income NV buildings is still not evident in the current literature. Therefore, this study proposes a simulation-based framework that considers the relationships between wall materials, airflow dynamics, and thermal comfort using a computational fluid dynamics (CFD) approach by spatially plotting the thermal comfort within the NV spaces.The study analyses locally accessible wall materials, subjecting them to different operating conditions within NV dwelling units of low-income housing in India. Out of the analyzed wall materials, aerated autoclaved blocks exhibited a significant indoor temperature reduction of 20.7 % compared to the compressed stabilized earth blocks, with constrained airflow exacerbating temperature fluctuations. The global implications of these findings are substantial for urban low-income dwellers experiencing excessive heat. Mass housing efforts worldwide can benefit from using thermally efficient materials in construction thereby improving living conditions, and mitigating the impact of climate change on thermal comfort and health.

Simultaneous Measurement of Thermal Conductivity and Volumetric Heat Capacity of Thermal Interface Materials Using Thermoreflectance.

Thermal interface materials are crucial to minimize the thermal resistance between a semiconductor device and a heat sink, especially for high-power electronic devices, which are susceptible to self-heating-induced failures. The effectiveness of these interface materials depends on their low thermal contact resistance coupled with high thermal conductivity. Various characterization techniques are used to determine the thermal properties of the thermal interface materials. However, their bulk or free-standing thermal properties are typically assessed rather than their thermal performance when applied as a thin layer in real application. In this study, we introduce a low-frequency range frequency domain thermoreflectance method that can measure the effective thermal conductivity and volumetric heat capacity of thermal interface materials simultaneously in situ, illustrated on silver-filled thermal interface material samples, offering a distinct advantage over traditional techniques such as ASTM D5470. Monte Carlo fitting is used to quantify the thermal conductivities and heat capacities and their uncertainties, which are compared to a more efficient least-squares method.

A thermogravimetric analysis of residual char formation by gilsonite-filled, polyfurfuryl alcohol composites: acid treatment of gilsonite

Gilsonite (GLS), a natural bitumen containing a considerable amount of asphaltenes, is expected to leave heavy char after pyrolysis; however, its high potential as an efficient filler to enhance the thermal properties of composite materials is surprisingly neglected throughout the literature. On the other hand, polyfurfuryl alcohol (PFA) has attracted much attention as a thermosetting resin due to its excellent char-leaving characteristics, the renewable nature of the monomer(s), and high accessibility at an affordable cost. This study aimed to investigate the thermal stability and char-forming performance of composites made of a PFA resin matrix filled with chemically modified GLS. To modify the ash and sulfur contents of GLS, the nitric acid leaching process was performed according to a D-optimal experimental design approach. The nitric acid concentration (10, 20, and 30 wt.%), treatment time (30, 75, and 120 min), and reaction temperature (30 °C, 50 °C, and 70 °C) were set as the input variables. The morphology (SEM), chemical structure (FTIR), thermal stability (TGA), sulfur content, and ash content of the GLS particles were characterized before and after acid treatment. Thermogravimetric analysis revealed the lowest ash content for GLS after treatment with 10 wt.% acid conc. at 75 °C for 75 min. The nitric acid concentration, reaction temperature, and time were the most influential parameters for improving the ash content of GLS according to their order of appearance. In addition, the inorganic form of sulfur, pyrite, was separated through the acid leaching process. Then, the PFA resin matrix was filled with modified GLS particles at different weight percentages (5, 10, 15, and 20 wt.%) and cured in the presence of an acid catalyst. The thermal stability of the PFA resin was negatively affected by the presence of GLS, probably due to oxidation reactions and disruption of the integrity of the resin structure.

The impact of helium clusters on the electronic thermal transport properties of tungsten plasma-facing materials at finite temperatures

In this work, we investigated the impact of different concentrations of helium (He) impurities on the electronic thermal transport properties of tungsten plasma-facing materials (W-PFMs) at finite temperatures using the W-He tight-binding (TB) potential model. We found that the electronic transport performance decreases with increasing He atom concentration at different sites, where the greatest reduction in the electrical conductivity of the system is caused by the introduction of He atoms at neighboring tetrahedral sites. As the temperature increases, the electrical conductivity decreases, while the electronic thermal conductivity increases. Importantly, the higher the temperature is, the weaker the response of the electrical conductivity and electronic thermal conductivity to the He atom concentration. We suggest that this behavior is attributed to the diverse contributions of scattering mechanisms within various temperature ranges. Furthermore, as the temperature increases, the electron scattering mechanism gradually transitions from electron-impurity scattering to electron-electron scattering. Additionally, our calculated atomic resolved electrical conductivity data indicate that at lower temperatures, the electrical conductivity is predominantly contributed by W atoms around the He cluster.

The thermal conductivity properties of porous materials based on TPMS

In this study, the effective thermal conductivity of materials based on a porous TPMS structure is investigated. The resulting structure is similar to a matrix and consists of identical pore cells that are strictly periodic in all directions. These pores have several characteristic sizes, and by altering them, materials with predictable effective thermal conductivity can be created. This work investigated materials based on Triply Periodic Minimal Surface (TPMS) of Schwarz P, Schoen IWP and Neovius. The calculation of thermophysical properties was performed using the numerical finite element method in the Ansys software package. Heat transfer in the structures was studied both with and without considering air. The empirical coefficient “n” for the Aivazov–Domashnev formula is expressed analytically. This relationship allows for the creation of materials with predictable thermophysical properties, taking into account the thermal conductivity of non-porous materials. The results of numerical modeling are validated by analytical Austin’s models and experimental data. The samples for the experimental study were made using additive technologies from PETG, ABS, PLA plastic and photopolymer resin. The study has scientific and applied significance, since a method is proposed for predicting the thermal conductivity of materials with an ordered structure. Several solid-state samples of elementary cells were made publicly available for designing materials with predictable thermal conductivity. The novelty of the work lies in obtaining the dependence of effective thermal conductivity on the geometric parameters of the ordered structure for materials with thermal conductivity in a wide range from 0.12 to 400 W/(m°C).

Enhancement of the underground cable current capacity by using nano‐dielectrics

AbstractIn most underground power cables, cross‐linked polyethylene (XLPE) is utilized as the main insulating material, while polyvinyl chloride (PVC) is usually used as a nonmetallic sheath or jacketing for the cable. Accordingly, improving the electrical and thermal characteristics of these materials leads to an increase in cable dielectric strength, besides a rise in the current capacity of the underground power cables. Thus, enhancing the thermal characteristics of cable insulation is the goal of many research studies. In this regard, increasing the current capacity of underground power cables is an essential topic for electrical distribution and transmission networks. This usually occurs by increasing the cross‐sectional area of the cable conductor, which means raising the cost of transmitting electrical energy. Another proposed alternative may be to improve the thermal properties of the dielectric material using nanotechnology to allow better dissipation of heat resulting from the cable losses. This article proposes the use of nano‐composite dielectrics to increase the current capacities of underground power cables. Nano‐fillers are used to enhance the thermal and electrical characteristics of XLPE and PVC, which represent cable dielectric materials. Accordingly, in this paper, many experiments are conducted on various nano‐dielectric materials to choose the most appropriate nano‐dielectrics for improving both the thermal and electrical properties. Hence, measurements are performed on the thermal and electrical properties of dielectric nano‐materials manufactured in the laboratory. Further, calculations of the cable's current capacities by the use of the measured properties of nano‐dielectrics are done considering several backfill soils. From the obtained measurements and calculations carried out on cable capacities, it is concluded that the use of XLPE/ZnO 5 wt.% as the insulation and PVC/ZnO 5 wt.% as the jacket material increased the cable current capacity by 6.2% for a cable of 33 kV rating, 9.2% for 66 kV cable, and 15.7% for 220 kV cable when wet clay is used as backfill soil. From the calculations carried out it is found that the use of nano‐composite dielectrics reduces the temperature of the cable components by significant values. For example, the core temperature of the 33 kV cable is reduced by 15.6°C, while for the 66 kV cable, the cable core temperature is decreased by 12.6°C, and for 220 kV the conductor temperature is reduced from 71.3°C to 58.3°C when each cable is loaded by its rating.

Investigating thermal and free vibrational properties of fabric sandwich composite materials for car hood application

Textile fabric wastes are the second most polluting materials in the world after plastic. This study investigated the thermal and free vibrational properties of the sandwich composites prepared from recycled fabric materials. Grey cotton fabric(C) and wool garment waste (G) reinforced a polyester matrix in a different layer arrangement (CCCC, CGCG, CGGC, GCCG, GGGG, and chopped). Thermogravimetric analysis (TGA) and dilatometry were performed to determine the thermal properties. TGA results showed similar initial weight loss for GCCG, CCCC, and CGGC (within a range of 25 °C–800°C) and for GCGC, GGGG, and chopped arrangements. All composites exhibited thermal stability up to 305°C. Between 310°C and 405°C, a gradual mass loss was observed, followed by more significant degradation above 405°C and residual mass loss observed at 655°C. Dilatometry tests reveal minimal volume change up to a heating temperature of 300°C for all durations (20 min, 40 min, and 60 min). In addition, the free-vibration analysis indicated poor energy-absorbing properties for CCCC, while CGGC sandwich composite specimen exhibited better energy-absorbing properties. Based on these results, it can be concluded that these composite materials are suitable for applications such as car hoods, which typically function below 105°C temperatures.

A VFM-based identification method for anisotropic thermal-mechanical properties of sheet metals using the digital image correlation and infrared thermography assisted heterogeneous test

The accurate characterization of the anisotropic thermal-mechanical constitutive properties of structural sheet metals at elevated temperatures and under nonuniform stress/strain states is crucial for the precise hot plastic forming and structural behavior evaluation of an engineering sheet part. Traditional thermal-mechanical testing methods rely on the assumption of states homogeneity, leading to a large number of tests required for the characterization of material anisotropy and nonlinearity at various high temperatures. In this work, a highly efficient identification method is proposed that allows the simultaneous characterization of the anisotropic yielding, strain hardening and elasto-plasticity thermal softening material properties using the minimum number of tests, releasing the limitations of traditional identification methods. This is implemented by performing a digital image correlation and infrared thermography assisted heterogeneous high temperature test and processing the full-field measurement data based on the principle of virtual work. A double-notched tensile specimen configuration combined with a center-to-periphery temperature gradient is designed first to enable the high heterogeneity of stress/temperature states. Simulations of the heterogeneous tests are then performed to supply idealized reference data that can be used to evaluate the identification sensitivity of the proposed identification algorithm. After the numerical validation of the methodology, it is then applied to the TC4 titanium alloy sheet specimen using the self-developed experimental setup. The experimental identification results verify that the multiple anisotropic thermal-mechanical elasto-plasticity constitutive parameters can be accurately identified from the heterogeneous test with high computation efficiency, significantly simplifying the testing process in comparison to applying multiple traditional homogeneous tests. The current work provides an effective and convenient alternative to high temperature identification strategies used by the material processing community.

Mechanical and thermal properties of fumed silica‐incorporated silane‐terminated urethane/epoxy‐interpenetrating polymer network nanocomposites

AbstractIn this study, it was aimed to improve the mechanical and thermal properties of epoxy materials based on diglycidyl ether of bisphenol‐A‐based. For this purpose, three different nanocomposite materials were prepared at various ratios including a fumed silica nanoparticle‐reinforced epoxy nanocomposite (FSN), an epoxy/silane‐terminated urethane (STU) hybrid interpenetrating polymer network (IPN) nanocomposite (SHIN), and a fumed silica‐reinforced epoxy/STU hybrid IPN nanocomposite (FSHIN). While synthesizing SHIN, 3‐isocyanato propyl trimethoxy silane (ICPTMS) and poly (hexamethylene carbonate) diol were used. The synthesized STU polymer chains were crosslinked by reacting them with TEOS via the sol–gel process. Therefore, hybrid networks were obtained. Moreover, fumed silica nanoparticles were incorporated into the hybrid networks via the sol–gel process for FSHINs. The three different nanocomposite materials exhibited much more improved properties than the neat epoxy. The most prominent nanocomposite was FSHIN. In comparison with the neat epoxy, Young's modulus, ultimate tensile strength, and Izod impact resistance values increased at ratios of 53%, 50%, and 223%, respectively. Glass transition temperature values and char yield values increased substantially in all nanocomposites. However, thermal decomposition temperatures increased only for FSNs. Moreover, these values for FSHINs that were very close to those of the neat epoxy were considerably higher than those of SHINs.Highlights Fumed silica‐incorporated silane‐terminated urethane/epoxy IPN nanocomposites. Substantially improved mechanical properties and impact resistance. Improved thermal stability.

A Review of EPDM (Ethylene Propylene Diene Monomer) Rubber-Based Nanocomposites: Properties and Progress.

Ethylene propylene diene monomer (EPDM) is a synthetic rubber widely used in industry and commerce due to its high thermal and chemical resistance. Nanotechnology has enabled the incorporation of nanomaterials into polymeric matrixes that maintain their flexibility and conformation, allowing them to achieve properties previously unattainable, such as improved tensile and chemical resistance. In this work, we summarize the influence of different nanostructures on the mechanical, thermal, and electrical properties of EPDM-based materials to keep up with current research and support future research into synthetic rubber nanocomposites.