Total Electromagnetic Interference Shielding Research Articles

Engineering lightweight Poly(lactic acid) graphene nanoribbon nanocomposites for sustainable and stretchable electronics: Achieving exceptional electrical conductivity and electromagnetic interference shielding with enhanced thermal conductivity

The challenge of creating flexible and sustainable electronics with properties such as lightweight, electrical and thermal conductivity, and electromagnetic interference (EMI) shielding is addressed in this study. Carbon nanotubes and graphene are commonly used in flexible electronic devices, but gaps exist in their conductivity and flexibility. A novel and scalable fabrication method is introduced, involving the creation of bio-based nanocomposites by integrating flexible and high aspect-ratio graphene nanoribbons (GNRs) into a poly (lactic acid) (PLA) matrix. The nanocomposites were drawn above the glass transition temperature (Tg) of PLA, resulting in the formation of extended shish structures, as observed in scanning electron microscope (SEM) images. These structures significantly enhanced thermal and electrical conductivities, as well as EMI shielding features. The combination of flexible GNR nanofillers with uniaxial stretching led to a substantial increase in Young's modulus, tensile strength, and toughness by approximately 550 %, 440 %, and 600 %, respectively, most likely due to the increased network connection despite the higher flexibility of GNRs. Moreover, in-plane thermal conductivity registered a notable enhancement of approximately 110 %. The EMI shielding reached 26 dB, with an absorption contribution to EMI shielding of around 45 %. Additional improvement was achieved through foaming of the stretched samples, resulting in multilayer structures with alternative extended shish and foam structures. Furthermore, a significant augmentation of approximately 33 dB in total EMI shielding of the foamed samples, accompanied by an 85 % increase in SEA was documented. These promising findings underscore potential applications across diverse domains, including thermal interface materials, electronic packaging, capacitors, and energy storage devices, with a specific emphasis on the realm of sustainable and stretchable electronics.

Ammonium Bicarbonate Templated 3D PDMS/rGO@CoFe2O4 Composite Foams for Effective Electromagnetic Interference Shielding and Thermal Insulation

In the past 50 years, the electronic and communication industries have grown exponentially, which has caused major concerns about electromagnetic (EM) pollution. In recent years, more thrust has been given to development of polymer composites to lessen electromagnetic interference (EMI) pollution. In the present work, porous polydimethylsiloxane (PDMS) composite foams based on cobalt ferrite (CoFe2O4) and reduced graphene oxide (rGO) are produced through the ammonium bicarbonate template approach. The resulting foams possess increased EMI shielding effectiveness via the absorption‐dominated mechanism due to the fact that PDMS foam functions as a three‐dimensional (3D) network, rGO offers the requisite conductive channel, and CoFe2O4 produces the necessary magnetic loss. The total EMI shielding effectiveness (SE) of PDMS/rGO composite foams without CoFe2O4 is 24 dB, however, with different weight percentages of CoFe2O4 added (3%, 6%, and 9%), the EMI SE increases to 41 dB for 3 mm thickness. The heat insulation performance of the material is also studied, and the measured thermal conductivity is 0.0391 Wm−1 K−1, which is very low value. The attributes of the composite foam underscore its excellent thermal insulation performance and its capacity for EMI shielding, rendering it highly suitable for diverse applications across various fields.

Optimization of CoFe2O4 nanoparticles and graphite fillers to endow thermoplastic polyurethane nanocomposites with superior electromagnetic interference shielding performance.

The rapid growth, integration, and miniaturization of electronics have raised significant concerns about how to handle issues with electromagnetic interference (EMI), which has increased demand for the creation of EMI shielding materials. In order to effectively shield against electromagnetic interference (EMI), this study developed a variety of thermoplastic polyurethane (TPU)-based nanocomposites in conjunction with CoFe2O4 nanoparticles and graphite. The filler percentage and nanocomposite thickness were tuned and optimized. The designed GF15-TPU nanocomposite, which has a 5 mm thickness, 15 weight percent cobalt ferrite nanoparticles, and 35 weight percent graphite, showed the highest total EMI shielding effectiveness value of 41.5 dB in the 8.2-12.4 GHz frequency range, or 99.993% shielding efficiency, out of all the prepared polymer nanocomposites. According to experimental findings, the nanocomposite's dipole polarization, interfacial polarization, conduction loss, eddy current loss, natural resonance, exchange resonance, multiple scattering, and high attenuation significantly contribute to improving its electromagnetic interference shielding properties. The created TPU-based nanocomposites containing graphite and CoFe2O4 nanoparticles have the potential to be used in communication systems, defense, spacecraft, and aircraft as EMI shielding materials.

Improved electromagnetic interference shielding performance of silicone rubber/CNTs composites by porous structure design via green supercritical CO2 foaming

In this study, the relationship between porous structure and electromagnetic interference (EMI) shielding performance of polymer foams is established. A green supercritical CO2 foaming technology is utilized to construct silicone rubber (PMVS)/carbon nanotubes (CNTs) foams with tunable porous structures (porosity, cell size, cell density and cell gradient structure). Notably, the introduction of moderate porosity (within 40 %) simultaneously enhanced the total EMI shielding effectiveness (SET) and absorption coefficient (A). PMVS/CNTs foam reached a maximum SET of 62.3 dB, a 35.4 % increase over solid PMVS/CNTs composite. Additionally, small-cell PMVS/CNTs foam shows a higher A under the same porosity, while large-cell foam exhibits higher SET. Moreover, gradient porous PMVS/CNTs, combining advantages of large and small cells, maintains a high A (78 %) and exhibits superior SET (52.7 dB), along with exceptional EMI shielding stability (with SET and A retaining 97.7 % and 99 %, respectively, after 1000 cycles of compression). This work provides a theoretical foundation for optimizing EMI shielding performance by regulating porous structures.

Thermally tunable ethanol impregnated PDMS/CoZTO/SWCNT composite architecture for smart electromagnetic shielding

Shape memory elastomer composites with externally stimulated shielding capability are greatly sought to protect high-end artificial intelligence-based electrical and telecommunication devices in the military, aerospace, robotics, etc., from electromagnetic interference (EMI). However, the fabrication of such composites integrated with externally responsive green EMI shielding capabilities is promising but greatly challenging. Herein, ethanol (thermally active phase) mixed polydimethylsiloxane (PDMS)/single wall carbon nanotube (SWCNT)/cobalt doped zinc tin oxide (CoZTO) hybrid composite with an active guest method was devised. This design strategy explores how the thermally controlled liquid-gas phase transition led microstructural modifications regulate the macroscopic shielding features like absorption enhancement and reflection minimization. The composite adapts the 72.18 % volumetric actuation by liquid-to-vapor phase transition of ethanol at 80 °C, promoting the total EMI shielding value up to 48.77 dB from 18.4 dB at 20 GHz due to microstructure induced electromagnetic modifications. Additionally, a green index of 7.2 confirms the absorption dominance over reflection shielding in the studied composite. Furthermore, ethanol-generated foamed architecture of composite offers pressure-sensitive on-off shielding tunability, which accounts for the potential use in manufacturing advanced RF switches.

Flexible free-standing BixSey@C/PEDOT:PSS thermoelectric composite film with high-performance electromagnetic interference shielding

Due to the component advantages and structural features, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) based inorganic–organic composite films shows huge application potential in various fields. However, there are few reports on the bi-functions of thermoelectric (TE) and electromagnetic interference (EMI) shielding for the PEDOT:PSS-based functional films. Herein, metal–organic frameworks (MOFs)-derived BixSey@C sheets with average size about ∼ 7.32 μm are obtained via the solvothermal reaction and selenization pyrolysis treatment, and then flexible free-standing BixSey@C/PEDOT: PSS (BSCP) composite films are obtained by a feasible vacuum filtration combined with cold pressing treatment, using different contents of BixSey@C content as inorganic component. Micrometer BixSey@C sheets are uniformly dispersed in the PEDOT:PSS matrix constructing bi-functional composite films with unique layered structure. When the MOFs-derived BixSey@C content is 70%, BSCP-70 composite film gets a power factor of 11.23 μW m−1 K−2 at 340 K. Meanwhile, the BSCP-70 composite film reaches the highest average total EMI shielding effectiveness (SET) value of 45.0 dB at only 41.9 μm thickness at X-band. Based on multi-physical properties of MOF-derived BixSey@C and PEDOT:PSS, flexible BixSey@C/PEDOT:PSS composite films display good application potentiality in the flexible TE devices and EMI shielding protection.

Synergistically-enhanced flexible electromagnetic interference shielding nanocomposites

The unique three-dimensional architecture endows melamine-based carbon foam with many intriguing merits, including lightweight, good mechanical strength, high electrical conductivity, good chemical stability, flexibility, etc. Hence, this kind of carbon foam is thought to be a promising candidate for next-generation electromagnetic interference (EMI) shielding material. However, its practical application is restricted by its moderate EMI shielding property. In this work, we proposed multiple synergistic strategies to address this issue. Specifically, a Co3O4/carbon nanotubes (CNTs)/carbon foam composite was experimentally constructed using a facile synthetic process. The results indicated that the total EMI shielding effectiveness (SET) of the Co3O4/CNTs/carbon foam composite with a thickness of 3 mm could reach 25.6 dB in the frequency range of 8.2–12.4 GHz, which was about 10 dB higher than that of pristine carbon foam. Moreover, the compressive strength of the composite was much higher than that of pristine carbon foam, and it also delivered a higher EMI shielding performance retention even after 100 and 200 times bending, respectively. Lastly, the role of multiple synergistic effects of Co3O4 and CNTs in influencing the composite’s EMI shielding performance was comprehensively discussed.

Tailored distribution of 1D nanoparticles in co-continuous EMA/TPO flexible polymeric blends used as emerging materials for suppressing electromagnetic radiation

Electromagnetic interference (EMI) is unwanted noise or interference that often affects electronic equipment and human health. An effective EMI shielding material is needed to protect electronic equipment and human health to block EMI signals. In this work, we have developed electrically conductive polymer composites via the preferential localization of MWCNTs in a co-continuous ethylene-co-methyl acrylate (EMA)/thermoplastic polyolefin (TPO) (80/20 w/w) binary blend system using a solution mixing technique. The electrical percolation threshold was achieved by incorporating 3 to 5 wt% of MWCNT in the blend matrix. FESEM and TEM images indicated a co-continuous morphology in which MWCNT was thermodynamically and kinetically driven into the EMA phase of the polymer blend. The DC and AC conductivity of the fabricated composite was significantly increased upon loading the MWCNT in the polymer composite. A total EMI shielding effectiveness of −35 dB was achieved by adding 15 wt% MWCNT into the matrix in the frequency range of 14.5–20.0 GHz, along with good thermal conductivity, dielectric properties, and mechanical properties.

Electromagnetic interference shielding in lightweight carbon xerogels

With the increasing use of high-frequency electronic and wireless devices, electromagnetic interference (EMI) has become a growing concern due to its potential impact on both electronic devices and human health. In this study, we demonstrated the performance of lightweight, electrically conducting 3D resorcinol-formaldehyde carbon xerogels, of 2.4 mm thickness, as an EMI shieldin the frequency range of 10–15 GHz (X-Ku band). The brittle carbon xerogels revealed complex porous structures with irregularly shaped pores that were randomly distributed. Electrochemical characterization revealed that the material behaved as an electrical double-layer capacitor. The carbon xerogels displayed reflection-dominated (∼ 84%) shielding behavior, with a total EMI shielding effectiveness (SE) value of ∼ 61 dB. The absorption process also contributed (∼ 16%) to the total SE. This behavior is attributed to the carbon xerogels' complex porous network, which effectively suppresses EM waves.

Development of highly flexible electromagnetic interference shielding composites for electronic applications using Cobalt/ Hevea brasiliensis seed husk carbon dots/Bamboo microfibre-polyvinyl alcohol

In this present work a highly flexible electromagnetic interference (EMI) shielding composite was prepared from industrial crop for advanced engineering applications. The EMI shielding composite product was further tested for its effectiveness on high frequency bands of 8–20 GHz. Through pyrolysis, the leftover rubber seed hulls were converted into carbon dots (C-dots). The composites were characterized after being made using the solution casting process. The inclusion of carbon dots increased the relative permittivity up to 9.4 with the lowest loss factor of 0.62 at 8 GHz, according to the findings. The hysteresis loop showed a broader "S" curve for cobalt with biochar at a 2 vol% concentration. Additionally, the composite contains 3 vol% of cobalt/carbon dots records a maximum tensile strength of 54.7 MPa, modulus of 0.88 GPa, and % of elongation of 128.7. However, the composite contains 5 vol% of cobalt/carbon dots (PBC4) had a total EMI shielding effect of − 54.3 dB at 20 GHz. These enhanced EMI shielding composites with highly retained flexibility could be employed as a protective material in telecommunication; chip sets manufacturing, defense and medical applications. • Carbon dots were successfully prepared from waste rubber seed hulls. • Cobalt/C-dots compound structure PVA composite prepared. • Measurement of total EMI shielding efficiency is improved for 2 vol% Co/C-dots. • The total EMI shielding up to − 54.7 dB was measured for Ku band. • The tensile and hardness properties measures 45% of improvement.

Nickel oxide-sprinkled in-situ grown hierarchal graphitic jungle anchored feathery aluminum foam: A novel material for remarkable electromagnetic waves absorption

Electromagnetic waves (EMW) absorbing materials with low density are in high demand because the miniaturization of devices requires high electromagnetic shielding. Metal foams (especially open-cell Aluminum foam, OCAF), due to their lightweight and reasonable mechanical properties, are considered encouraging materials for the aforementioned applications. OCAF counters the high-density issue, and also makes it compatible with impedance matching. Here nickel oxide (NiO)- sprinkled in-situ grown hierarchal graphitic carbon nanofiber anchored feathery OCAF (Al–NiO–CNF OCAF) is synthesized through a novel template method. The materials are explored intensively using different physico-electro-chemical, mechanical, and magnetic techniques. The EMW absorption capacity gets remarkably increased (four times) with the presence of NiO and hierarchal graphitic jungle. The total electromagnetic interference shielding is found to be ∼84 dB at 10.4 GHz, out of which 82 dB is the absorption component (>98%). The prepared Al–NiO–CNF OCAF approves the new pathway for the use of metal-based lightweight materials for high EMW absorption applications. The Al–NiO–CNF OCAF has shown better mechanical and environmental stability. This study demonstrates a simple alternative material for promising electromagnetic interference shielding and EM absorption capabilities in various orientations.

Preferential localization of conductive filler in ethylene‐co‐methyl acrylate/thermoplastic polyolefin polymer blends to reduce percolation threshold and enhanced electromagnetic radiation shielding over K band region

AbstractTo minimize radiation pollution at ultra‐low filler concentrations, there is a growing interest in microwave‐absorbing materials based on polymer blends composites. Herein, ethylene‐co‐methyl acrylate (EMA)/thermoplastic polyolefin (TPO) blend composites were prepared by employing solution mixing utilizing conductive Vulcan XC 72 carbon black (VCB) as nanofiller. The work focused on the reduction of electrical percolation and outstanding electromagnetic interference (EMI) shielding performance in low loading caused by the preferential distribution of carbon particles in one phase (ethylene‐co‐methyl acrylate copolymer) of the co‐continuous immiscible polymer blend. The fabricated conductive blend was further tested to ensure its superiority in physic‐mechanical and thermal stability. The morphology analysis reveals that the VCB particles are selectively localized in EMA phase of the blend which facilitates the formation of compact spatial conductive network throughout the matrix for electronic hopping. High electrical conductivity is achieved in the scale 10−2 S/cm for the prepared composites with 30 wt% of carbon black loading whereas a total EMI shielding effectiveness of −29 dB and thermal conductivity of ~0.75 W/m·K are achieved for this same filler content. This study reveals that the fabricated conductive polymer nanocomposites can be effectively utilized as promising EMI shields in the future generation of stretchable and wearable electronics.

Frequency‐selective electromagnetic interference shielding carbon spacer yarn fabric/polyurethane foam composites

Abstract3D fabric‐reinforced composites with electromagnetic interference (EMI) shielding performance are in urgent demand to deal with the electromagnetic (EM) pollution. In this work, carbon spacer fabrics/polyurethane foam (CSF/PUF) composites were prepared via in situ integration of PUF with fabrics. Their EMI shielding and frequency‐selective performances were realized via designing 3D fabric. CSF/PUF possesses two types of Fabry‐Pérot cavities that generated incident EM waves' resonances according to the quarter‐wavelength theory. The average total EMI shielding effectiveness (SET) of 3CSF/PUF was 69.6 dB in the X band. The maximum EMI SET of 3CSF/PUF was up to 83.2 dB in 9.7 GHz. The peaks of EMI SE move to the high‐frequency region with the increase of carbon spacer yarns' density. Moreover, CSF acted as a reinforcement role and significantly improved the mechanical properties of PUF. The peak stress under compression, three‐point bending and low‐velocity impact increased by 4.2‐, 5.6‐, and 4.9‐folds, respectively. CSF/PUF also exhibited good thermal insulation properties, maintaining a temperature difference of at least 19.5°C across its thickness at 60°C. The as‐prepared spacing yarn carbon fabric‐reinforced composite foams may raise an interest to explore multifunctional EMI materials via fabric structure design.

Dopants versus defects: Intense confrontation of nitrogen-doped Ti3C2Tx for enhanced electromagnetic interference shielding

MXene has been extensively studied in electromagnetic interference (EMI) shielding. In this work, the defects-rich nitrogen-doped Ti3C2Tx (N-doped Ti3C2Tx) was fabricated for EMI shielding. An intense confrontation of dopants versus defects was observed: N dopants offering extra electrons improved electrical conductivity. And the defects-rich characteristics contributed to its reduction, which consisted of crumpled morphology, structural collapse, the introduced N heteroatoms, and pore nature. The end of this conflict revealed that heteroatoms N led to a significant improvement of conductivity and suppressed the negative impact of defects, resulting in the reflection-dominant EMI shielding feature. Owning to greater advantage of dopants, the N-doped Ti3C2Tx prepared at 550 °C/paraffin composite with the most defects exhibited the highest conductivity. And it achieved the maximum total EMI shielding effectiveness from 8.0 to 12.4 GHz (covering the entire X-band) of 62.15 dB. This work presents a new paradigm for MXene-based materials utilizing the structure-property relationship and manifests an enormous application promise for new high-efficiency EMI shielding materials in the future.

Superb electromagnetic shielding polymer nanocomposites filled with 3-dimensional p-phenylenediamine/aniline copolymer nanofibers@copper foam hybrid nanofillers

The polymer nanocomposites with 3-dimensional (3D) nanofillers can form a 3D network and attain a uniform distribution of nanofillers, which benefits the transfer of charge carriers and phonons as well as the dispersion of stress at a very low loading of nanofillers. These polymer nanocomposites with high mechanical properties would have great potential for thermal and electrical conduction as well as electromagnetic interference (EMI) shielding. In this paper, the 3D epoxy nanocomposites are manufactured by stuffing epoxy resin into 3D p-phenylenediamine-aniline copolymer nanofibers@Cu foam (P-PANI@f-Cu) hybrid nanofillers that are constructed by electrophoretic deposition of phosphoric acid doped P-PANI copolymer nanofibers onto the surface of sodium hydroxide oxidized Cu foam. Benefiting from 3D continuous network of P-PANI@f-Cu hybrid nanofillers, the electrical conductivity and thermal conductivity of 3D P-PANI@f-Cu/epoxy nanocomposites with the P-PANI loading of 0.262 wt% could achieve 7.71 ± 0.04 S cm−1 and 5.4670 ± 0.0085 W m−1K−1, respectively, which are much better than that of pure epoxy (insulator and 0.2310 ± 0.0017 W m−1K−1, respectively) and epoxy composites filled with only Cu foam (4.46 ± 0.03 S cm−1 and 2.7907 ± 0.0057 W m−1K−1, respectively). Meanwhile, with a thickness of 1.8 mm, the average total EMI shielding effectiveness (SET) of 3D P-PANI@f-Cu/epoxy nanocomposites in the X-band range reaches a high value of 66.14 dB, which is capable of effectively shielding the electromagnetic signal between Bluetooth earphone and smartphone in the practical application. Furthermore, the 3D P-PANI@f-Cu hybrid nanofillers can efficiently prevent the crack growth in the epoxy nanocomposites and improve their mechanical properties including hardness and elastic modulus.

In-situ growth of TiO2 nanoparticles on crumpled Ti3C2Tx with negative permittivity for electromagnetic interference shielding

MXenes have been attracting enormous attention owning to their high electronic conductivity, abundant functional groups, and surface modification ability in the application of electromagnetic interference (EMI) shielding. In this work, TiO2 nanoparticles were in-situ grown on the surface of crumpled Ti3C2Tx MXene to generate TiO2/MXene heterointerfaces and create an extra absorption path. It was found that Ti3C2Tx with less oxidation time generated more TiO2. This intriguing phenomenon was caused by the fact that more functional groups escaped in the pre-oxidation step, creating extra active sites and allowing for more intense oxidation in a shorter period. Besides, the hybrid showed negative permittivity due to the metal-like conduction behavior, contributing to the reflection-dominant shielding mechanism. The TiO2/MXene heterostructure with negative permittivity exhibited an excellent total EMI shielding effectiveness of 73.98 dB at a filler content of 25 wt% in 8.0–12.4 GHz (covering the X band) at 2 mm. This work offers a new insight into exploring the structure-property relationship for MXene-based materials.

Electromagnetic interference shielding epoxy composites with satisfactory thermal conductivity and electrical insulation performance enabled by low-melting-point alloy layered structure

Nowadays, electronic packaging materials requires electrical insulation, heat conduction and electromagnetic interference (EMI) shielding performance. With the inspiration raised by Janus materials, introducing low-melting-point alloy (LMPA) layered structure in epoxy resin is potential method to acquiring satisfying properties. The layered structure is originated from LMPA particles self-sedimentation and closely stacking. Meanwhile, LMPA particles are coated by epoxy resin that could remain the overall electrical insulation. When loading of 20 vol% LMPA, composite obtained thermal conductivity 1.23 W/mK (the LMPA side), total EMI shielding value of 35.56 dB at 30 GHz, and electrical conductivity of 5.00 × 10−8 S/cm. Further, the introduction of boron nitride nanosheet (BNNS) into the composites could promote isotropic heat conduction and improve the electrical insulation. This paper has provided novel LMPA layered structure, showing great promise for applications of electronic packaging materials with heat conduction, electrical insulation and EMI shielding properties.

Lightweight leaf-structured carbon nanotubes/graphene foam and the composites with polydimethylsiloxane for electromagnetic interference shielding

One of the key requirements for novel electromagnetic interference (EMI) shielding composites is lightweight. In this article, we report a kind of novel foam materials (labeled as CGF) with a leaf structure composed of carbon nanotubes (CNTs) and reduced graphene oxide (rGO) for EMI shielding. It was found that adding 20 wt% CNTs into the new material could expand the conductive network and increase the conductivity of CGF by 274.4%. Such an expansion could facilitate the multiple reflections and absorptions of EMWs within the materials and boost the conversion efficiency to induced currents (ICs), resulting in excellent total EMI shielding effectiveness (SE) of 71.4 dB at mass per unit area of only 12.5 mg·cm−2. Moreover, the CGF materials manifest exceptional EMI SE divided by density (SED) or mass per unit area (SEMA) value were 1142 dB·cm3·g−1 and 5712 dB·cm2·g−1, respectively. Considering the radar chart prepared by the total EMI SE, SED and SEMA, CGF reflects excellent comprehensive performance. Being compounded with polydimethylsiloxane (PDMS), the EMI SE of CGF/PDMS show excellent pressure resistance. After press CGF/PDMS for 100 times under a pressure of 500 kPa, the EMI SE retention rate can reach 71.6%. Furthermore, the addition of CGF increase the heat resistance indexes (THRI) of the composites by 6 °C. In conclusion, CGF/PDMS are extremely practical in the field of EMI shielding.

Multilayer polymeric nanocomposite thin film heater and electromagnetic interference shield

An unprecedented highly transparent glass heater and electromagnetic interference (EMI) shield is fabricated, using a layer-by-layer assembly of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and silver nanowires (AgNWs) to replace both the conventional indium tin oxide (ITO) and other metal- and carbon-based electrodes proposed to date. The novel simple fabrication of the electrode, unlike many other reported technologies, does not require any vacuum or chemical vapor deposition, hot pressing, pulsed laser irradiation, UV-lithography, and electroplating. The ∼ 80 nm layered thin film offers an exceptionally high figure-of-merit of 610 with a low sheet resistance of 6.4 Ω sq–1 and a total EMI shielding of 23 dB, attenuating 99.5% of the incident electromagnetic waves in the X-band frequency range at high optical transparency of 91%. The transparent heater, sandwiched between two ∼ 2.5 mm glass substrates, shows promising Joule heating performance when successfully de-ices a 2 mm ice in less than a minute while maintained under a sub-zero temperature of – 10 °C. A numerical heat transfer model is also developed to assess the temperature profile distribution and confirm the de-icing time.

Thin and efficient EMI shielding materials from binary thermoplastic blend nanocomposites

AbstractEMI shielding materials and related research are of very relevance in this era of electronic gadgets. Here this report presents a binary thermoplastic blend nanocomposite system comprising poly‐(trimethylene terephthalate) and polyethene compatibilized with multiwalled carbon nanotubes, which are showing superior electromagnetic interference (EMI) shielding compared to similar systems. The blend composition with a 90/10 ratio of PTT/PE was showing the optimum properties when a MWCNT concentration of 1 wt% was incorporated. The compatibilization efficacy was analyzed and confirmed through scanning and tunneling electron microscopes. The MWCNTs are preferably localized in the PTT phase. The blend system provides an electrical percolation threshold of 0.19 wt% due to the double percolating effect of the blend system and MWCNT in the PTT phase. It was observed that the EMI shielding value shows a corresponding increase with MWCNT loadings. The most favorable value obtained for EMI shielding effectiveness was ~32 dB and it was with 3 wt% MWCNT of film thickness 2 mm in range of frequency 2–4 GHz. The PTT/PE/MWCNT system was not considered for EMI applications anywhere else. The theoretical support of the experimental data was examined for DC conductivity employing different models such as Voet, Bueche, and Scarisbrick and the actual contribution of reflection, absorption, transmission loss to the total EMI shielding was done with Power balance. The present work is a facile and cost‐effective method to fabricate lightweight and materials with high EMI shielding properties for mobile phones.