C/SiO2 and C/SiC composite foam monoliths from rice husk for thermal insulation and EMI shielding

Chithra, A.; Ramanan, Rajeev; Prabhakaran, K.

doi:10.1007/s42823-021-00303-9

Cited by 7 publications

(5 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The maximum total EMI shielding effectiveness of 52.4 dB observed in the present case at a carbonization temperature of 900 °C is much higher than the maximum shielding effectiveness of 45.5 dB obtained by Chen et al for a carbon grid prepared from wood pulp fabric matting heat-treated at 2000 °C wherein the empty grid size was 0.6 mm . Further, the EMI shielding effectiveness of the cotton cloth-derived CCGs is much higher than that of porous carbon monoliths prepared from other biomasses. ,,,,− The specific shielding effectiveness and thickness-normalized specific shielding effectiveness are two important parameters used for a comparison of EMI shielding effectiveness. Specific shielding effectiveness (SSE), which is determined by dividing the total shielding effectiveness with volumetric density, ranges from 144.4 to 105.0 dB cm 3 g –1 for CCGs prepared at PF solution concentration in the range of 30–70 vol %.…”

Section: Resultscontrasting

confidence: 58%

“…Recently, carbon foams and aerogels prepared from naturally renewable biomasses are becoming more important as these precursors are eco-friendly and sustainable, and their utilization for the production of carbon materials reduces the carbon footprint. Carbon foams and aerogels developed from biomasses such as lignin, cellulose, sucrose, ,, wheat flour, natural cotton, sawdust, rice husk, wheat straw, and silk have been reported with very high EMI shielding effectiveness.…”

Section: Introductionmentioning

confidence: 99%

“…The materials used to mitigate this problem are called EMI-shielding materials. Metallic, ceramic, polymeric, and composite materials with adequate electrical conductivity, dielectric permittivity, and magnetic permeability are widely explored for EMI shielding applications. − The advancement of mobile communication and extensive use of electronic gadgets in the defense and aerospace sectors necessitate the development of lightweight materials with excellent corrosion and fire resistance and showing outstanding EMI shielding performance at a low thickness. , In this regard, carbon-based materials outperform their metallic, ceramic, and polymeric counterparts. ,− In addition, the easy preparation of carbon-based materials with engineered porosity from low-cost precursors makes them more attractive. Carbon foams and aerogels prepared from synthetic and natural raw materials are studied for EMI shielding.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Upcycling of Used Cotton Cloth to Robust Fire-Resistant Carbon Composite Grids with Excellent EMI Shielding

Saraswathy,

M R,

Prabhakaran

2024

ACS Appl. Eng. Mater.

Self Cite

View full text Add to dashboard Cite

The castoff cotton cloth is used for the preparation of robust carbon composite grids (CCGs) by bonding the warp and fill yarns at their contact point by successive impregnation with a solution of sucrose and phenol formaldehyde (PF) followed by curing and carbonization at 900 °C. The CCGs are characterized by X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectra (XPS), and scanning electron microscopy (SEM) analysis. The width, thickness, empty grid size, and density of the CCGs are modulated in the ranges of 0.354−0.388, 0.587−0.657, 0.357−0.299 mm, and 0.24−0.55 g•cm −3 , respectively, by the PF solution concentrations in the range of 30−80 vol %. The tensile strength and modulus increase from 0.42 to 2.73 and 18.8 to 111 MPa, respectively, when the PF solution concentration increases from 30 to 80 vol %. The CCGs are fire-resistant and exhibit reflection-dominated EMI shielding. The absorption contribution and total EMI shielding effectiveness increase from 30.1 to 46.9 and 34.8 to 52.4 dB, respectively, when the PF solution concentration increases from 30 to 70 vol %. The multiple internal reflections within the empty grid space, interfiber porosity, and lumen of the carbonized cotton fiber led to attenuation of electromagnetic (EM) waves by both conductive losses due to mobile electrons and dielectric losses due to polarization at the functional groups and the large area of carbon−carbon and carbon−air interfaces. The thin, robust, and large-area CCGs produced can be a candidate for high-performance electromagnetic interference (EMI)-shielding material with excellent fire resistance for the strategic sector.

show abstract

Section: Resultscontrasting

confidence: 58%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Upcycling of Used Cotton Cloth to Robust Fire-Resistant Carbon Composite Grids with Excellent EMI Shielding

Saraswathy,

M R,

Prabhakaran

2024

ACS Appl. Eng. Mater.

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, metal-based shielding materials are being replaced because of their heavy weight, corrosive nature, and reflection-based shielding mechanism, which can cause secondary EMI. Current research focuses on alternate materials such as two-dimensional (2D) nanomaterials like MXenes − and carbon-based materials such as carbon nanofibers (CNFs), , carbon foam, − and graphene , due to their versatile features. Among them, one-dimensional (1D) CNF materials and their polymer composites assume great interest because of their unique advantages .…”

Section: Introductionmentioning

confidence: 99%

Tellurium Nanoparticles Incorporated into Electrospun Poly(acrylonitrile) Nanofibers, Followed by Carbonization and Their Poly(dimethylsiloxane) Composites for Electromagnetic Interference Shielding

Sharma,

Joseph,

M S

et al. 2024

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

Miniaturized, flexible, and highly integrated electronic devices have become an essential part of everyday life. This has contributed to a huge increase in the emission of electromagnetic (EM) waves and has resulted in electromagnetic interference (EMI), which can affect the function of the devices. So, high-performance EMI shielding materials assume great importance. Low density and favorable flexibility are desirable properties for these shielding materials. The present study reports tellurium nanoparticles (Te NPs) incorporated into an nitrogendoped carbon nanofiber (Te-CNF) prepared through electrospinning, followed by carbonization, for EMI shielding applications. Tellurium is a metalloid with a narrow band gap, and the incorporation of Te NPs in carbon nanofiber (CNF) may alter the electronic properties to improve the 3D conductive network. Te NPs also can introduce polarization sites and heterointerfaces in CNF. Te-CNF exhibited an average EMI shielding effectiveness of 37 dB in the X-band region with a thickness of 0.08 mm and a density of 0.499 g cm −1 and possessed a high electrical conductivity of 0.68 S cm −1 . Te-CNF exhibited higher SE A values compared to SE R due to the synergistic effect of the incorporated Te NPs and nitrogen-doped CNF, such as interfacial polarization, conduction loss, polarization loss, and multiple scattering and multiple internal reflections of EM waves. Poly(dimethylsiloxane) (PDMS), which is a common flexible substrate, has been used to improve the flexibility and ease of handling of the prepared Te-CNF mat. Thus, the EMI shielding property of Te-CNF and the flexibility of the PDMS substrate have been made use of in the composite to achieve a flexible EMI shielding material. The Te-CNF and its PDMS composites are lightweight, flexible, and hydrophobic and exhibit a high EMI shielding property.

show abstract

“…Various processing approaches reported a variety of polymer-based composite foams as EM wave shielding materials including mesocarbon microbead (MCMB), carbon nanotube, carbon black, and so forth as reinforcement − and incorporating dielectric and magnetic fillers such as Fe 2 O 3 , Fe 3 O 4 , MnO 2 , ZnO, SiO 2 , MXene, and so forth − and various biomass and agricultural residues such as banana leaf, rice husk, cotton, saw dust, and so on. − Zhang et al reported a novel method of preparation of phthalonitrile-based carbon foam by using a chemical blowing agent and achieved high EMI SE with an attenuation of ∼51.2 dB . Recently, Xiao et al reported the fabrication of nitrogen-doped phthalonitrile carbon composites containing porous graphene and adenine formulated by the high-energy ball-milling molding–sintering procedure that showed outstanding mechanical properties and notable EMI shielding properties quantified as 47 dB for 0.94 mm thick sample …”

Section: Introductionmentioning

confidence: 99%

Phthalonitrile and Cyanate Ester-Based Carbon Foams for Effective Electromagnetic Interference Shielding Applications

Sreelal,

Saraswathy,

Thomas

et al. 2024

ACS Appl. Eng. Mater.

View full text Add to dashboard Cite

Lightweight materials with high electromagnetic interference (EMI) shielding effectiveness (SE) are greatly sought to address the increasing electromagnetic menace, especially in aerospace domain. In this work, lightweight foam-based EMI shielding materials are realized from phthalonitrile (PN), cyanate ester (CE), and a blend of PN−CE resin matrices by infusing into a rigid graphitic board (RGB) template. The low-density (0.3 and 0.4 g/cm 3 ) carbon foams have achieved good electrical conductivity of 0.45−0.62 S/cm, high total EMI shielding efficiency of ∼72−78 dB, specific EMI shielding of 75−195 dB, and thickness-normalized EMI shielding of 150−390 dB, indicating the excellent shielding of incident EM waves.The heterocyclic cross-linked networks formed from the ring formation polymerization of nitrile and cyano moieties are instrumental in conferring high EMI SE to the carbon foams. The primary EMI shielding mechanism is determined to be absorption. A thermal degradation mechanism proposed further confirms the formation of a hybrid graphitic structure conducive for high EMI SE. The polarization effects brought on by the built-in nitrogen-containing cured framework also contribute to the shielding efficiency. These lightweight carbon foams are prospective EMI shielding materials expected to be useful in aerospace, aeronautical, and high-end industrial fields in the future.

show abstract

C/SiO2 and C/SiC composite foam monoliths from rice husk for thermal insulation and EMI shielding

Cited by 7 publications

References 71 publications

Upcycling of Used Cotton Cloth to Robust Fire-Resistant Carbon Composite Grids with Excellent EMI Shielding

Upcycling of Used Cotton Cloth to Robust Fire-Resistant Carbon Composite Grids with Excellent EMI Shielding

Tellurium Nanoparticles Incorporated into Electrospun Poly(acrylonitrile) Nanofibers, Followed by Carbonization and Their Poly(dimethylsiloxane) Composites for Electromagnetic Interference Shielding

Phthalonitrile and Cyanate Ester-Based Carbon Foams for Effective Electromagnetic Interference Shielding Applications

Contact Info

Product

Resources

About