Promoting the electromagnetic interference shielding of Ti3C2Tx flakes by loading Fe3O4 nanoparticles: Insights into the performance of oligo-layers exposed to microwave interferences

This study aims to provide insights into the absorption and shielding performances of Fe₃O₄ modified oligo-layered Ti₃C₂T_x towards microwave electromagnetic interference. Oligo-layered Ti₃C₂T_x was modified by Fe₃O₄ nanoparticles (60 nm) via a facile electrostatic assembly approach at different loading rates. This composite was shown to have high dielectric constant and high permeability compared with oligo-layered Ti₃C₂T_x. The microwave electromagnetic absorbing and shielding performances were monitored through a vector network instrument with focuses on the EMI performance. The sample Ti₃C₂T_x/Fe₃O₄ with a 5:1 mass ratio of Ti₃C₂T_x to Fe₃O₄ displayed the optimized EMI shielding performance. The average SE value was 62.19 dB, and the maximum value was 68.72 dB at 18 GHz with a 2.6 mm thickness. The EMI shielding mechanism was understood based on the conductive loss, magnetic loss, dipole polarization, and multiple scattering. Results suggests that Ti₃C₂T_x/Fe₃O₄ composites are expected to be superior EMI shielding material.     

Annealed Ti3C2Tx: A green and tunable electromagnetic interference shielding material

Electromagnetic interference (EMI) shielding materials are receiving more and more attentions and becoming a hot research topic because of their wide range of applications in life, defense and other fields. The development of green EMI shielding materials with tunable shielding effectiveness (SE) is a high pursuit and a great challenge for researchers. Here, we restricted the growth of TiO₂ on the Ti₃C₂T_x surface by adjusting the annealing temperature. This regulated the dipole and interface polarization and the construction of the conductive network, and improved the impedance matching. The Ti₃C₂T_x/TiO₂ heterostructured material was rationally designed and achieved an efficient EMI SE of 35.1 dB at 18 GHz when the annealing temperature was 600 °C. This work develops new avenues for the future design of efficient, controllable green EMI shielding materials. Simultaneously, this heterostructured material has great potential as a versatile green shielding material for civil, commercial and military aerospace applications.     

Ti3C2Tx-coated diatom frustules-derived porous SiO2 composites with high EMI shielding and mechanical properties

Effective electromagnetic interference (EMI) shielding materials have garnered substantial interest for their efficacy in attenuating electromagnetic wave energy, ensuring data confidentiality, ensuring the operational stability of fragile electronic systems. To begin, artificially cultured diatom frustules (DF)-derived porous silica (DFPS) skeletons were constructed as templates in this study. Porous ceramics hot-pressed at 800 °C displayed a high compressive strength with a high specific surface area due to their three-dimensional (3D) multilayered and porous structures. Then, mechanically robust Ti₃C₂T_x/DFPS composites with exceptional EMI shielding performance were fabricated by immersing porous DF-based ceramics into Ti₃C₂T_x solutions and annealing in an argon environment to increase the materials’ shielding efficiency (SE). The EMI SE of composites hot-pressed at 800 °C achieved the maximum EMI SE of 43.2 dB in the X-band and a compressive strength of 67.5 MPa, establishing a hitherto unreported balance of mechanical characteristics and shielding performance. Prolonged transmission paths, multiple dissipation, scattering and reflection of electromagnetic energy were achieved using a well-maintained hierarchical porous silica framework decorated with MXene, with adsorption caused by surface MXene serving as the primary shielding mechanism for the composites. Due to their superior overall performance, MXene/DFPS EMI shielding composites have a bright future in the aircraft sector as delicate electronic device components.     

Multilayer Ti3C2Tx: From microwave absorption to electromagnetic interference shielding

Ti₃C₂T_x MXene has attracted extensive attention in the field of electromagnetic (EM) protection over recent years. Multilayer Ti₃C₂T_x (M-Ti₃C₂T_x), as an intermediate product of MXene ultra-thin structure, has potential advantages in the field of EM protection. Herein, the M-Ti₃C₂T_x was obtained by HCl/LiF etching Ti₃AlC₂. The microwave absorption (MA) and electromagnetic interference (EMI) shielding performance of Ti₃AlC₂ and M-Ti₃C₂T_x were compared. The mechanism research of MA and EMI shielding indicates that the construction of local conductive network plays a leading role in the EM wave attenuation. The sample with 30% M-Ti₃C₂T_x display RL_min of ?50.26 dB, and corresponding bandwidth of 4.64 GHz at the thickness of 1.7 mm. Especially, the metastructure based on the EM parameters of M-Ti₃C₂T_x/wax exhibits ultra-wide bandwidth (15.54 GHz). Our research will provide a basis for the design of MXene-based EM protection performance.     

Bifunctional Ti3C2Tx–CNT/PANI composite with excellent electromagnetic shielding and supercapacitive performance

Ti₃C₂T_x exhibits excellent electromagnetic (EM) shielding and electrochemical properties. However, the inherent re-stacking tendency and easy oxidation of Ti₃C₂T_x limit its further application. In this study, a multi-walled carbon nanotube/polyaniline composite (CNT/PANI, denoted as C–P) was introduced into Ti₃C₂T_x nanosheets to obtain a Ti₃C₂T_x–CNT/PANI composite (T@CP). Owing to the integrated effects of Ti₃C₂T_x and C–P, the contribution of absorption was significantly improved, which finally enhanced the EM shielding performance of T@CP. The highest total EM shielding effectiveness (SE_T) was close to 50 dB (49.8 dB), which was substantially higher than that of pure Ti₃C₂T_x (45.3 dB). Moreover, T@CP demonstrated outstanding supercapacitive performance. The specific capacitance of T@CP (2134.5 mF/cm² at 2 mV/s) was considerably higher than that of pure Ti₃C₂T_x (414.3 mF/cm² at 2 mV/s). These findings provide a new route for the development of high-efficiency Ti₃C₂T_x-based bifunctional EM shielding and electrochemical materials.     

The effect of honeycomb pore size on the electromagnetic interference shielding performance of multifunctional 3D honeycomb-like Ag/Ti3C2Tx hybrid structures

To solve pollution problems caused by electromagnetic waves, advanced three-dimensional (3D) honeycomb Ag/Ti₃C₂T_x hybrid materials were produced by a microwave hydrothermal method. The Ag/Ti₃C₂T_x hybrid materials retained their hollow sphere structure after the polymethyl methacrylate (PMMA) template was removed by annealing. The hybrid materials changed from hydrophilic to hydrophobic and exhibited cross-surface heat insulation and reflection-dominant electromagnetic interference shielding (EMIS) performance owing to their special honeycomb structure. This study innovatively explored the influence of different particle sizes of honeycomb holes on EMIS performance. In particular, the Ag/Ti₃C₂T_x 5 μm hybrid materials had an excellent average EMIS performance of 51.15 dB in the X-band and 56.64 dB in the K_u-band. The superior performance was due to conduction loss, interface polarization, multi-reflection, and scattering caused by the 3D porous structure of the Ag/Ti₃C₂T_x hybrid materials. In general, Ag/Ti₃C₂T_x hybrid materials with honeycomb structures retained the advantages of lightweight, hydrophobicity, and EMIS performance, illustrating the great application prospects of these materials in high-end electronic equipment.     

2D Ti3C2Tx MXene/aramid nanofibers composite films prepared via a simple filtration method with excellent mechanical and electromagnetic interference shielding properties

Electromagnetic shielding (EMI) materials are becoming more and more important because of the increasingly serious radiation pollution. The preparation of high mechanical strength, ultrathin, lightweight, flexible materials with excellent EMI shielding performance have so far been elusive. Here, we try to prepare an ultrathin, lightweight and flexible film with excellent EMI shielding performance using one-dimensional aramid nanofibers (ANFs) and two-dimensional few-layered Ti₃C₂T_x through a simple filtration method. The ultimate tensile strength and strain of the film are up to 116.71 MPa and 2.64%. The EMI shielding effectiveness and the specific EMI shielding efficiency are 34.71 dB and 21971.37 dB cm² g⁻¹, which will be no recession after 1000 times bending. Our results show that a practical EMI shielding material with excellent performances has been successfully prepared, which will be widely applied in wearable electronics, robot joints, and precision instrument protection and so on.     

Highly conductive and flexible bilayered MXene/cellulose paper sheet for efficient electromagnetic interference shielding applications

In this work, a robust and flexible bilayered MXene/cellulose paper sheet with superhigh electrical conductivity was prepared via vacuum-assisted filtration and a subsequent hot-pressing process for electromagnetic interference (EMI) shielding applications. By tightly assembling few-layered MXene (f-Ti₃C₂T_x) on the cellulose substrate via hydrogen bonds, an effective and interconnected conductive network was constructed in the paper sheet, resulting in a high electrical conductivity of 774.6–5935.4 S m^?1 at various f-Ti₃C₂T_x loadings. The highly conductive MXene layer can promptly reflect a great amount of incident EM waves, a process which preceded the transmission of EM waves in the cellulose matrix. Owing to the highly efficient reflection-dominated EMI shielding mechanism, the resultant bilayered MXene/cellulose paper sheets exhibit excellent EMI shielding effectiveness of 34.9–60.1 dB and specific EMI shielding efficiency of 290.6–600.7 dB mm^?1. Moreover, the MXene/cellulose paper sheets demonstrated improved mechanical strength (up to 25.7 MPa) and flexibility due to the mechanical frame effect acted by the cellulose substrate. Consequently, the robust and flexible bilayered MXene/cellulose paper sheet is a promising candidate for application in next-generation electric devices.     

Fabrication and electromagnetic interference shielding effectiveness of Ti3Si(Al)C2 modified Al2O3/SiC composites

A dense alumina fiber reinforced silicon carbide matrix composites (Al₂O₃/SiC) modified with Ti₃Si(Al)C₂ were prepared by a joint process of chemical vapor infiltration, slurry infiltration and reactive melt infiltration. The conductive Ti₃Si(Al)C₂ phase introduced into the matrix modified the microstructure of Al₂O₃/SiC. The refined microstructure was composed of conductive phase, semiconductive phase and insulating phase, which led to admirable electromagnetic shielding properties. Electromagnetic interference shielding effectiveness (EMI SE) of Al₂O₃/SiC and Ti₃Si(Al)C₂ modified Al₂O₃/SiC were investigated over the frequency range of 8.2–12.4 GHz. The EMI SE of Al₂O₃/SiC-Ti₃Si(Al)C₂ exhibited a significant increase from 27.6 to 42.1 dB compared with that of Al₂O₃/SiC. The reflection and absorption shielding effectiveness increased simultaneously with the increase of the electrical conductivity.     

Multi-phase heterostructures of flower-like Ni(NiO) decorated on two-dimensional Ti3C2Tx/TiO2 for high-performance microwave absorption properties

Three-dimensional flower-like Ni(NiO) decorated on two-dimensional Ti₃C₂T_x/TiO₂ composites were successfully synthesized by an in situ solvothermal reaction, and the electromagnetic (EM) wave absorption performance of the hybrids were explored at 2.00–18.00 GHz. The as-prepared Ni(NiO)/Ti₃C₂T_x/TiO₂ composites include flower-like Ni(NiO) with uniform distribution on the surface of Ti₃C₂T_x MXenes and part of them get into the space between interlayers. The Ni(NiO)/Ti₃C₂T_x/TiO₂ composites exhibit a maximum reflection loss (RL) value of ?41.74 dB at 14.96 GHz with the absorber thickness of merely 1.3 mm and the effective absorption bandwidth (EAB) reaches 3.20 GHz. The outstanding electromagnetic wave absorbing performance can be attributed to the dielectric loss of Ti₃C₂T_x MXenes and multi-phase heterostructures, the magnetic loss of Ni(NiO) and their synergistic loss mechanism. Moreover, the zigzag path formed by flower-like Ni(NiO) also has a great consumption effect on electromagnetic waves by incurring the eddy current under the affect of alternating EM waves. The laminated structure of Ti₃C₂T_x MXenes also dissipates microwaves by offering the space for multiple reflections and scattering. This paper furnished a novel modus for synthesizing original EM wave absorption materials and making the balance among thickness, broad bandwidth, oxidation resistance and light weight, which makes Ni(NiO)/Ti₃C₂T_x/TiO₂ composites a hopeful material for microwave absorption (MA).     

Rapid preparation,thermal stability and electromagnetic interference shielding properties of two-dimensional Ti3C2 MXene

Two-dimensional (2D) MXenes have attracted much attention due to their unique structural characteristics and novel performance in a variety of functions. The fabrication of 2D Ti₃C₂ MXene by acid etching usually requires a long period of over 10 h. In this work, we report on the rapid preparation, thermal stability and electromagnetic interference (EMI) shielding effectiveness of 2D Ti₃C₂ MXene. With the processing conditions optimized by adjusting the etching time and temperature, Ti₃C₂ MXene with a scattered accordion-like structure has been successfully achieved by etching Ti₃AlC₂ powders with 40% HF at 50 °C for only 0.5 h. The as-synthesized Ti₃C₂ was stable at temperatures up to 300 °C in air, but stable in vacuum at temperatures up to 800 °C. The as-synthesized Ti₃C₂ MXene has good EMI shielding performance. The total shielding effectiveness of Ti₃C₂ in a WAX matrix exceeded 20 dB in the whole frequency ranging from 2 to 18 GHz. The maximum shielding effectiveness value achieved to 34 dB at 18 GHz as the Ti₃C₂ content was up to 70 wt%. This work provides an approach for the large scale preparation of the Ti₃C₂ MXene.     

Structural,thermal and dielectric properties of 2D layered Ti3C2Tx (MXene) filled poly (ethylene-co-methyl acrylate) (EMA) nanocomposites

Light-weight and flexible 2D MXene-based polymer materials with low dielectric loss and high dielectric constant have drawn great attention in the power systems and modern electronic field. A series of Ti₃C₂T_x/EMA composites were fabricated via simple solution casting followed by a compression molding method with various mass concentrations of Ti₃C₂T_x (0, 1, 3, 5, 8, 10, 12, and 15 wt%). Morphological and micro structural properties of the prepared composites were studied via X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM), where the distribution of Ti₃C₂T_x in the Ti₃C₂T_x/EMA composites was confirmed. Thermal behaviors were analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) investigations. The DSC analysis reveals that the % of crystallinity decreases from 11.06 with 1 wt% to 5.68 with 15 wt%, where Ti₃C₂T_x acts as an efficient nucleating agent. TGA data confirm the enhancement of the thermal stability of the composites upon increasing in Ti₃C₂T_x loading. The room temperature electrical and dielectric behavior of the studied composites were examined in the frequency range of 100 Hz–5 MHz. In this work, the 10 wt% of Ti₃C₂T_x loaded poly (ethylene-co-methyl acrylate) composite (EMA) showed higher dielectric permittivity (ε′ = 124.22) with lower dissipation loss (tan δ = 0.051) at 100 Hz among all weight percentages. The behavior of charge carriers in the prepared composites was studied by utilizing the impedance spectroscopy technique. The electrical parameters were calculated from the fitted Nyquist plots with a corresponding circuit model. I–V curves confirmed the conduction mechanisms of the composites. This beneficial enhancement in electrical properties recommends the composite can be utilized in flexible electronic storage devices.     

Electrically conductive and corrosion resistant MAX phases with superior electromagnetic wave shielding performance

MAX phases have emerged as promising corrosion-resistant electromagnetic interference (EMI) shielding materials. Herein, four MAX phases: Ti₃SiC₂, Ti₃AlC₂, V_0.5Cr_1.5AlC, and Nb₄AlC₃, were synthesized via solid–liquid reactions. The electrical conductivities of Ti₃SiC₂, Ti₃AlC₂, V_0.5Cr_1.5AlC, and Nb₄AlC₃ are 14.7 × 10³, 15.5 × 10³, 5.1 × 10³, 8.0 × 10³ S/cm, respectively, and the corresponding average EMI shielding effectiveness values in the frequency of 18–26.5 GHz are 53.9, 69.2, 19.4, and 29.0 dB, respectively. Most importantly, these MAX phases are highly corrosion resistant under acidic conditions. Despite the exposure to the acidic environment and a slight decrease in the electrical conductivity, the corroded MAX phases exhibited excellent EMI shielding properties compared to the pristine MAX phases. Additional analysis showed that reflection was the primary EMI blocking mechanism. The study offers a guide for designing MAX phase ceramics that exhibit high EMI shielding performance in corrosive environments.     

Advanced Ti3C2Tx MXene-modified cement nanocomposites toward high efficiency electromagnetic functional materials for green buildings

The proliferation of electronic devices and wireless communication is leading to serious electromagnetic (EM) interference. In this work, Ti₃C₂/cement composites were developed as high efficiency EM functional materials by introducing exfoliated Ti₃C₂T_x MXene with cement for green buildings with EM shielding function. In the composites, few-layered Ti₃C₂ MXene were dispersed homogeneously throughout the cement matrix. The EM properties of the composites were studied as a function of the MXene content. With increasing MXene content, real and imaginary part of permittivity was significantly improved owing to the polarization and electrical conduction caused by the MXene phase. Composites with 15 wt.% MXene showed good EM absorbing properties with a maximum effective absorbing bandwidth of 2.67 GHz. Strong EM shielding can be achieved when MXene content increased to 25 wt.%. The EM shielding effectiveness of such composites was higher than 22.0 dB, and the dominating shielding mechanism was EM absorption. This work finds new materials for the development of advanced green buildings with EM shielding function.     

Lightweight and robust Ti3C2Tx/carbon nanotubes foam with tuneable and highly efficient microwave absorption performance

In this study, a lightweight and robust Ti₃C₂T_x/carbon nanotubes (CNTs) foam (TCF) was fabricated using HCl-induced self-assembly, followed by vacuum freeze-drying. The electrical conductivity and mechanical elasticity of the TCF was higher than those of monolithic Ti₃C₂T_x foams. This was ascribed to the incorporation of CNTs into Ti₃C₂T_x preventing the stacking of the Ti₃C₂T_x nanosheets and producing a well-developed three-dimensional honeycomb-like porous network structure, which considerably improved impedance matching, promoted multiple reflection loss, increased conduction loss and polarisation loss, thus imparting remarkable microwave absorption properties to the TCF. The 1.72 and 1.92 mm thick TCF samples with absorber loadings of 4 wt%, which were obtained by immersing TCF into molten paraffin, followed by cutting it into coaxial rings, presented an optimum reflection loss of ?48.8 dB and a maximum effective absorption bandwidth (EAB) of 5.44 GHz, respectively. Moreover, upon increasing the thickness of the TCF samples from 1.52 to 4.92 mm, the EAB could be regulated from 4.16 to 18 GHz, respectively. In this study, we developed a facile method for fabricating a lightweight and robust TCF, which met the ‘light, thin, broad, and strong’ criteria and presented a broad EAB and remarkable dissipation capability, for microwave absorption materials.     

Enhanced room temperature ammonia response of 2D-Ti3C2Tx MXene decorated with Ni(OH)2 nanoparticles

Due to the expansion of human production activities, toxic ammonia (NH₃) is excessively released into the atmosphere, being a huge threat to human health and the natural environment. Therefore, it is of great significance to design an easy-synthesized gas-sensing material with both good room temperature sensitivity and selectivity for trace-level NH₃ detection. Herein, we fabricate a chemiresistive NH₃ gas sensor with enhanced performance based on Ni(OH)₂/Ti₃C₂T_x hybrid materials. The Ni(OH)₂/Ti₃C₂T_x hybrid materials are synthesized by an in-situ electrostatic self-assembly method. Attributed to the formation of interfacial heterojunctions and the modulation of carrier density, the Ni(OH)₂/Ti₃C₂T_x hybrid sensor exhibits high response, outstanding repeatability, good selectivity and stability in low concentrations of NH₃. Moreover, the Ni(OH)₂/Ti₃C₂T_x hybrid sensor has a higher response to 10 ppm NH₃ at the relative humidity of 40% and 60%, which makes it promising for applications in real complex environments with high humidity. Benefitting from the low power consumption and easy fabrication process, the Ni(OH)₂/Ti₃C₂T_x hybrid sensor possesses a broad application prospect in the internet of things (IoT) environmental monitoring.     

Improvement of electromagnetic interference properties of 3D few-layer graphene composite by means of freeze-drying

In this paper, we present a facile, green, and scalable approach for preparing high-quality few-layer graphene (FLG) nanoplatelets through a jet cavitation process. The electromagnetic interference (EMI) performance of FLG of three different lateral sizes is investigated. The midsized FLG (M-FLG) exhibits the best EMI performance. The jet-exfoliation technology used herein preserves the structure of FLG with few structural defects. The I_D/I_G ratio of M-FLG is as low as 0.092. Furthermore, we introduce 20 wt% M-FLG into paraffin wax to obtain a bulk material for conducting shielding measurements. The shielding effectiveness (SE) in the X-band is 19.28 dB, which exceeds that of unexfoliated graphite. Finally, we use freeze-drying technology to inhibit stacking of the graphene suspension during drying. The SE of the freeze-dried M-FLG (M-FLG-fd) increased considerably to 39 dB. The results indicate that jet cavitation combined with freeze-drying substantially improved the dielectric properties and absorption capabilities of FLG.     

Synergistically improved thermal stability and electromagnetic interference shielding effectiveness (EMI SE) of in-situ synthesized polyaniline/sulphur doped reduced graphene oxide (PANI/S-RGO) nanocomposites

Polyaniline (PANI) and its composite with sulphur doped reduced graphene oxide (S-RGO) have been successively synthesized via in-situ chemical oxidative polymerization of aniline in presence of 10 wt. % S-RGO nanosheets. Physico-chemical analyses of the synthesized nanomaterial was performed with various characterization techniques such as X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), Atomic Force Microscopy (AFM) and Thermogravimetric analysis/Differential Scanning Calorimetry (TGA/DSC). The results interpreted from the various characterizations confirm the doping of RGO with sulphur as well as strong interaction of PANI nanofibers and S-RGO nanosheets. TG/DSC curves confirm the enhanced thermal stability of polyaniline/sulphur doped reduced graphene oxide (PANI/S-RGO) nanocomposites with heat resistance index (T_HRI) of 155.2 °C in comparision to pure PANI (T_HRI = 145.3 °C) at a filler loading of 10 wt. %. TGA validates that thermal stability of PANI/S-RGO nanocomposite improves by 6–7 °C than pure PANI in terms of weight loss percentage at a temperature of 1117 °C. However DSC analysis confirms that PANI/S-RGO retains its structural integrity and conformity to temperatures as high as 900 °C beyond which the polymer composite starts to degrade. The electromagnetic interference shielding effectiveness (EMI SE) of PANI and PANI/S-RGO nanocomposites were measured via open-ended coaxial probe set-up connected to a Vector Network Analyser (VNA) at a broadband frequency range of 1–20 GHz (1000–20000 MHz). For EMI SE measurements the various nanomaterials were incorporated into paraffin wax and made into composite pellets of thickness 5 mm by solution casting technique. The dielectric properties, electrical conductivity and EMI SE were all greatly enhanced for the PANI/S-RGO/Paraffin composite pellets. The as synthesized PANI/S-RGO/Paraffin composite pellets exhibited highest EMI SE of ?22.5 dB (>99%) as compared to ?15.89 dB of PANI/Paraffin composite pellets. The prepared composite pellets revealed an absorption dominant mechanism of shielding with highest SE_A of ?14.6 dB for PANI/S-RGO/Paraffin composite pellets.     

Fabrication of 2D titanium carbide MXene/Au nanorods as a nanosensor platform for sensitive SERS detection

As an emerging label-free detection technology, surface-enhanced Raman scattering (SERS) has been used for biological detection, food safety, and environmental pollution owing to its high sensitivity, specificity and rapid response. However, traditional SERS substrates are unstable, prone to agglomeration, and demonstrate low productivity and high production cost. In this work, hybrids of a two-dimensional electron gas (2DEG) Ti₃C₂T_x monolayer and Au nanorods (AuNRs) were fabricated via self-assembly. Ti₃C₂T_x:AuNRs ratios were prepared, and each hybrid's SERS activity was evaluated through 4-aminothiophenol (pATP) detection. The Ti₃C₂T_x/AuNRs-1 substrate exhibited the weakest SERS performance, whereas the Ti₃C₂T_x/AuNRs-3 substrate had the best SERS activity enhancement, with a pATP limit of detection (LOD) of 10⁻⁹ M. When 30 sites on substrates were selected for SERS detection, the relative standard deviation (RSD) was found to be only 7.18 %, revealing the good performance sensitivity and high reproducibility of the Raman signal. The sensitivity of Ti₃C₂T_x/AuNRs-3 was also assessed with respect to a hazardous chemical, 1,2-bis (4-pyridyl) ethylene (BPE), revealing an LOD of 10⁻¹² M. For thiram, the LOD of Ti₃C₂T_x/AuNRs-3 was 10⁻⁸ M, which is considerably lower than the 1 ppm industry safety standard. A relative standard deviation RSD of 7.94 % indicates the high reproducibility and uniformity of the Raman signal of thiram for Ti₃C₂T_x/AuNRs-3. Compared with the LODs of 10⁻⁵ M and 10⁻⁶ M for commercial substrates T-SERS and Au nanorod arrays (AuNRAs), respectively, the 10⁻⁸ M LOD of our synthesized Ti₃C₂T_x/AuNRs indicates good sensitivity. Three kinds of pesticides were detected by Ti₃C₂T_x/AuNRs, and only Raman signal of thiram can be found, revealing the good selectivity for thiram. These results for Ti₃C₂T_x/AuNRs suggest its potential to serve as a novel SERS platform.     

A study to determine electromagnetic interference-shielding effectiveness on bio-based polyurethane foam reinforced with PVDF/MgO/Ni for emerging applications

The main objective of this study is to prepare nanoparticles-induced bio-based polyurethane foam to shield electromagnetic interference (EMI) radiation in the 8–12 GHz frequency range and compare the experimental result with optimization and simulation. Polyvinylidene fluoride (PVDF), magnesium oxide (MgO), and Nickel (Ni) nanoparticles were induced into bio-based PU (polyurethane) foam through absorption and hydrothermal reduction technique, which includes mechanical stirring, compressing, heating and evaporating. The design of experiment (DOE) methodology was used to find nanoparticle weight percentage (wt%). EMI shielding effectiveness of the bio-based PU foam composite was measured using Vector Network Analyzer (N5230A PNA-L). The weight percentages of the optimized sample were predicted using the response surface methodology (RSM), in which the central composite design (CCD) employed the weight percentages of the three nanoparticles as input and the results of the electromagnetic interference shielding effectiveness (EMI SE) experiment as the response output. The result from CCD showed that 3 wt% of PVDF, 10 wt% of MgO, and 1 wt% of Ni gave a maximum EMI SE of 27.78 dB. Then a confirmation sample was created for the same, and EMI SE was estimated empirically. The results obtained for the confirmation sample are 27.56 dB. Then, a scanning electron microscope image was taken for the confirmation sample to analyze nanoparticle-induced bio-based PU foam's structural properties. The SEM image with dxf format is imported into the radio frequency (RF) module to calculate the EMI SE through COMSOL Multiphysics. The simulated EMI SE for the confirmation sample was 25.1 dB.