Description:COMPLETE SPECIFICATION
[001] Low-weight concentrated MWCNTs and Graphene reinforce the polymer nanocomposite, a key component of the invention. The material is tested for multilayered structures, and its performance is verified in X-band to design an effective microwave absorber.

TECHNICAL FIELD

[002] The need for invention in the application of Multi-Walled Carbon Nanotubes (MWCNTs) in polymer nanocomposites, particularly for electromagnetic wave-absorbing materials (EMAMs), arises from the demand for effective electromagnetic interference (EMI) shielding in aerospace and electronic communications. Traditional materials often fall short in terms of mechanical robustness and lightweight properties, necessitating the development of advanced materials that can efficiently attenuate electromagnetic waves.

BACKGROUND
US6386131B1
A hybrid ship hull which includes three parts and whose stem and bow parts are made of composite materials while the mid-section is made of hybrid steel framing with a composite skin or of advanced double-steel hull or of conventional steel hull construction.

US4365580A
A composite hull construction for boats and the like is disclosed. A rigid inner box-like structure of steel or aluminum is provided and acts as the main structural element of the hull, a rigid synthetic foam core being intimately bonded to the exterior surfaces thereof. The exterior surface of the foam material is easily formed as desired to define the outer configuration of the hull and a layer of resin impregnated glass fibers is layed-up over the foam to provide a protective outer skin for the hull.

CN102317200B
A composite composition includes a plurality of carbon nanotube (CNT)-infused fibers dispersed in a matrix material. The amount of carbon nanotubes in the composition is in a range between about 0.1% percent by weight to about 60 percent by weight of the composite.

JP2005178756A
To provide a ship having a hull which has superior efficiency, high cost-efficiency, more lightweight, and especially length of 300 meters or more.

SOLUTION: The ship has a stemhead part, a stern part, and a midship part, and the structure of the stemhead part and the stern part is different from the midship part. The midship part is curved shape and made of a hybrid structure body. The port side and bow side of the midship part are made of a hybrid composite material internally supported by a lightweight frame supporting pressure load, namely, the midship part comprises an internal structure body made of a box-type girder structure or a longitudinal bulkhead structure.

CN106393732A
The invention discloses a manufacturing method of a yacht and solves multiple problems caused by dependence on hand laying-up by operators for machining of yachts. The method can comprise steps as follows: a yacht mold is waxed or coated with a release agent; a reinforced fiber material is laid in the yacht mold according to the yacht body structure layer requirement; vacuum auxiliary materials are laid on the upper surface of the reinforced fiber material in the yacht mold and comprise a flow guide net, release cloth, flow guide pipes, exhaust pipes, a grease injecting rubber seat, an exhaust rubber seat and a vacuum bag mold; the exhaust pipes connected with a vacuum pump are used for exhausting air between the yacht mold and the vacuum bag mold, and a vacuum mold cavity between the yacht mold and the vacuum bag mold is formed; the flow guide pipes connected with resin barrels are used for injecting resin into the vacuum mold cavity, and the yacht mold is impregnated with the resin along the flow guide net; and when the resin injected into the vacuum mold cavity is cured to form a yacht body of the yacht, the vacuum auxiliary materials are removed from the yacht mold, the yacht mold is removed, and the molded yacht body of the yacht is obtained.

CN111806036B
The invention discloses a bionic fiber reinforced composite material with high impact resistance and a preparation method thereof, wherein the combined bionic fiber composite material is formed by alternately laying forward spiral fiber resin layers and reverse spiral fiber resin layers which are bionic fiber resin layers in sequence according to a certain proportion, and then pressurizing, heating and curing; the forward spiral fiber resin layer and the reverse spiral fiber resin layer are arranged non-coaxially and are uniformly rotated and superposed along the central axis of each resin layer in a periodic manner, and the bionic fiber resin layer is formed by soaking a fibermaterial with a bionic structure in resin; the bionic fiber resin layer comprises a scorpion-chelate-like structure fiber resin layer, a mantis shrimp jawbone-like structure fiber resin layer and a small-tail Han sheep horns-sheath-like body and pheasant feather combined structure fiber resin layer; the invention effectively improves the shock resistance and interlayer toughness of the fiber composite material by combining and simulating the fiber material structure and the layering mode.

CN105841551A
The invention discloses a bionic energy absorbing and cushioning lining for a ballistic helmet. The bionic energy absorbing and cushioning lining consists of an anti-penetration scaly structure, a compound energy absorption sponge body and a multi-layer interlaced Kevlar fiber bushing, wherein the compound energy absorption sponge body is fixedly arranged on the multi-layer interlaced Kevlar fiber bushing; and the clam shell imitated anti-penetration scaly structure is fixedly arranged on the compound energy absorption sponge body. The anti-penetration scaly structure can effectively reduce the impact angle of a bullet and shrapnel to the helmet, reduces the structural weight and relieves the load of combatants; the compound energy absorption sponge body can play a cushioning protection role on such organs as cervical vertebrae and brains of the combatants; and the multi-layer interlaced Kevlar fiber bushing is formed by pasting multiple layers of Kevlar fiber cloth layer by layer at a certain angle, therefore has favorable strength in all directions, and is further improved in the anti-penetration capability.

US10457355B2
A motile buoyancy apparatus for use in a fluid. The motile buoyancy apparatus includes an outer layer, the outer layer having a performance surface. The motile buoyancy apparatus includes at least a portion including a first material. The first material is a non-Newtonian material. The at least a portion causes the performance surface to exhibit a shear rate-variable shear response.

CN103906795B
Provide the fiber reinforced polymer composites with improved damping capacity.On the one hand, fiber provides relatively high dynamic modulus in the frequency of the wide scope of given temperature for the composite material.On the other hand, polymer can be included with the viscoelastic polymer for the relatively high fissipation factor of given frequency and temperature.Centre frequency when further can adjust polymer to control the maximum loss factor for reaching polymer.Dramatically increasing for the relatively small reduction of fissipation factor and dynamic modulus is presented in the composite material so formed in the frequency of the wide scope of given temperature.Therefore, contrasted with conventional damping material, relatively high, constant fissipation factor is presented by the structure of composite material damping.Therefore, the embodiment of disclosed composite material dissipates significantly more energy during each vibration cycles than conventional damping material.

CN105308085B
The present invention relates to the hardening resin composition characterized by the polyalcohol (A), PIC (B) and polymer particles (C) for being 200~1500mgKOH/g containing average hydroxyl value；Or to contain polyalcohol (A), PIC (B) and polymer particles (C), necessarily containing PEPA (a2) as above-mentioned polyalcohol (A), and the amount of PEPA (a2) is the hardening resin composition more than 20 mass parts being characterized in the mass parts of total amount 100 of polyalcohol (A) composition.

CN101831193B
There is provided a fiber-reinforced composite material containing fibers having an average fiber diameter of 4 to 200 nm and a matrix material, the composite material having a visible light transmittance of 60% or more at a wavelength of 400 to 700 nm, which is a conversion value based on a thickness of 50 mum. A fiber-reinforced composite material composed of a matrix material and a fiber aggregate impregnated therewith is provided, in which when a segment length of a bright region corresponding to a pore region of the fiber aggregate is represented by L, which is obtained by statistical analysis of a unidirectional run-length image formed from a binary image obtained by binarization of a scanning electron microscopic image of the fiber aggregate, the total length of segments that satisfy L>=4.5 mum is 30% or less of the total analyzed length. A transparent multilayered sheet, a circuit board, and an optical waveguide are also provided which use a transparent substrate formed from this fiber-reinforced composite material.

US8096223B1
A multi-layer composite armor component that includes a plurality of layers of energy-dispersion objects including a first layer that includes a first plurality of energy-dispersion objects, wherein the first plurality of energy-dispersion objects in the first layer are held in place relative to one another in a closely-packed configuration; and a first layer of bonding material, wherein the first layer of bonding material has a first durometer value, and wherein the first plurality of energy-dispersion objects are held in place relative to one another via the first layer of bonding material. A method that includes providing a plurality of layers of energy-dispersion objects; arranging the first plurality of layers of energy-dispersion objects such that each of the first plurality of energy-dispersion objects are held in place relative to one another in a closely-packed configuration; and embedding the first plurality of energy-dispersion objects in a first layer of bonding material.

US8132495B2
An armor system for defeating rocket propelled grenade-type missiles and/or high velocity jets created by shaped charges directed at a vehicle includes a grid layer such as a net and/or an array of slats or bars (“RPG”) spaced from an outer surface of the vehicle by support members. The grid layer has a characteristic mesh size or bar/slat spacing to disrupt the missile firing mechanism. The system also has a shaped layer having a plurality of tapered members formed from a fiber-reinforced material, the tapered members positioned between the grid layer and the vehicle outer surface and having respective apex ends proximate the distant the grid layer and base ends, the tapered members defining with adjacent tapered members a plurality of depressions opening in a direction to receive an incoming conical portion of an unexploded RPG-type missile, or a jet emanating from an exploded RPG or other anti-armor device, and a layer of fiber-reinforced material abutting the base ends of the tapered members. The system may further include reactive elements disposed on surfaces of the tapered members defining the depressions to deflect impinging jets. The system may still further include one or more metal armor layers and one or more additional fiber-reinforced material layers disposed between the shaped fiber-reinforced material layer and the vehicle surface.

US7409920B2
A boat hull is provided that has a substantially seamless construction wherein the boat hull is an integral monolithic structure. In the formation of the boat, the boat interior components for example deck precursors are positioned in the mold prior to formation of the hull so that the boat hull can be made in a one shotmolding process.

US8365649B1
A multi-layer armor structure that includes a first composite layer and a second composite layer affixed to the first composite layer, wherein the second composite layer includes a metal plate and sound-wave-deadening material. The first and second composite layers form an overall composite layer. Some embodiments provide a multi-layer composite-armor article that includes a first metal layer, wherein the metal layer has an outer face that will be closer to an outermost surface of the armor article, and an inner face that will be farther from the outermost surface of the armor article; and a multi-layer polymer structure attached to the inner face of the first metal layer, wherein the polymer structure has an outer portion that is attached to the inner face of the first metal layer, and an inner portion that has a lower durometer value than the outer portion.

US20180370156A1
The present invention relates to a multilayer composition comprising a surface layer comprising a thermoplastic polymer A and a substrate layer comprising a polymeric composite material based thermoplastic (meth)acrylic matrix and a fibrous material as reinforcement. The multilayer composition is suitable for mechanical or structured parts or articles with a decorative surface aspect. The present invention concerns also a manufacturing process for multilayer mechanical or structured parts or articles and three-dimensional mechanical or structured parts.

US9475548B1
In a first aspect, a multi-hull platform boat comprises an upper deck or platform that is secured to a plurality of longitudinally extending hulls via a plurality of corresponding longitudinally extending connectors. Each connector extends from the bottom of the platform above a corresponding hull. The platform is constructed with a continuous uninterrupted planar lower support spanning the area between the connectors. The lower support is preferably made from one or more moldable materials and may be covered with a finish coating. In a second aspect, a multi-hull platform boat has a platform with a relatively planar upper support surface and a wedge-shaped base extending from the upper support surface of the platform to the bottom of the hulls. The base is wedge-shaped such that it increases in height from the front to the rear of the boat.

US5517934A
Disclosed is a plastic boat hull and a method for making a plastic boat hull by roto-molding a thermoplastic material in a mold cavity. The resultant boat hull in a preferred embodiment has an upper hull portion which is identical to the lower hull portion. The forebody, in a preferred embodiment is identical to the afterbody except that one is rotated 90° with respect to the other about the longitudinal axis of the hull. The boat hull shape provides for minimal weight, windage and surface area. The vessel has a wave-piercing bow, which creates an asymmetric water plane even though the fore body and after body are conceptually identical. The asymmetric water plane reduces pitching of the hull in rough water. In a preferred embodiment, two smaller hulls and one larger hull are combined with cross beams to form a trimaran sailboat.

JPH09507807A
The passengers' safety is ensured by reliably preventing local damage to the pair of hulls. The life of the hull body structure is extended and the weight of the hull body structure is reduced. The combined FRP hull body structure of a double-hulled ship comprises at least two hull bodies and a wet deck D bridged between these hull bodies. Each hull body has a laminated veneer structure, and this laminated veneer structure is formed by a laminated plate in which a large number of thin FRP panels 2 are laminated. Each FRP panel 2 is molded using a mixture of synthetic resin and fiber material. The wet deck D has a sandwich structure, in which a laminated FRP panel made of a mixture of synthetic resin and fiber material is adhered to the upper surface and the lower surface of a PVC foam material having a predetermined thickness. It is composed of three.

RU163516U1
1. A small fishing vessel containing a hull, including a metal section and a section made on the basis of polymer material, deck structures, bulkheads, characterized in that the metal section is made in the form of the lower part of the hull and is connected not lower than the cargo waterline with a section made of polymer composite material in the form of the upper part of the hull in one piece with the deck, and the connection of the parts of the hull is carried out by combining and fixing using means of insulation located on the inside s side of the housing and oriented at an angle thereto mounting surfaces, which are provided with upper and lower housing part, furthermore the lower part of the housing is provided with a fender, a superstructure and ship bulkheads are made of a polymeric composite materiala.2. A small fishing vessel according to claim 1, characterized in that for connecting the parts of the hull, as the mounting surfaces, shelves of corner profiles made of steel and polymer composite materials are used, as a means of insulation, a sealing gasket, and fixing of the mounting surfaces is made using means of tightening in the form bolts with nuts and washers. 3. A small fishing vessel according to claim 1, characterized in that the mounting surface of the upper part of the hull is made integral with the upper part of the hull.

RU211094U1
The utility model relates to the field of shipbuilding, in particular to the design of unmanned vessels designed to perform and support work in any area of the World Ocean in the field of marine engineering surveys, ensuring multi-agent interaction and marine telecommunications.The technical result is an increase in the initial stability of the vessel and a decrease in the amplitude of its oscillations relative to the water surface.The crewless catamaran contains a hull equipped with a keel and made of a hollow, sealed, streamlined shape, a radar communication unit, the hull is made of a composite on a resin matrix reinforced with fiberglass, and has a number of sealed compartments with technical equipment, a vessel control unit with integrated artificial intelligence, in a sealed transverse springboard compartment contains equipment for switching solar panels and a regulator of charging and voltage of the on-board network, two hulls rigidly connected by a transverse springboard made of a similar composite material, each of the hulls is equipped with a keel made of a similar composite material and rigidly fixed in the lower part of the hull to increase the initial stability of the vessel and the decrease in the amplitude of its oscillations relative to the water surface.

CN102471458B
Provided is a resin composition for fiber-reinforced composite materials which exhibits excellent flow properties and attains excellent impregnation into fibrous substrates and which can provide a cured product with excellent heat resistance. A resin composition for fiber-reinforced composite materials, characterized by comprising, as the essential components, (A) a poly(glycidyloxyaryl) compound, (B) a polymerizable monomer that consists of an unsaturated carboxylic acid or an anhydride thereof and has a molecular weight of 160 or less, (C) an aromatic vinyl compound or a (meth)acrylic acid ester, and (D) a radical polymerization initiator at an equivalent ratio of the glycidyloxy group of the component (A) to the acid group of the component (B), (glycidyloxy group)/(acid group), of 1/1 to 1/0.48 and at a molar ratio of the component (B) to the component (C), (B)/(C), of 1/0.55 to 1/2.

US9873488B2
A deep-drawn, marine hull having a sandwich structure and watercraft utilizing same are provided. The hull includes an outer skin having a waterproof outer surface, an inner skin having a compartment-defining outer surface and a shock absorbing, cellular core positioned between the skins. The skins are bonded to the core by press molding. The cellular core has a 2-D array of cells, each of the cells having an axis substantially perpendicular to the outer surfaces. Thickness of side walls of the hull is substantially uniform to maximize stiffness of the hull. The cells absorb energy of an impact at the outer surface of the outer skin by deformably crushing. Air trapped within cells which are not completely crushed or punctured by the impact provide the hull with buoyancy to allow the hull to float at the surface of a body of water.

US10208241B2
Proppants are used in oil and gas extraction, particularly in fracking operations. The invention relates to resin coated proppants. The coatings on proppants have antimicrobial materials incorporated within these coatings. The antimicrobially active agents are incorporated in a concentration less than 20% by weight of the coatings or the active agent from these coatings can be released from these coatings in the environment of the proppants.

US7854211B2
The present invention introduces a small boat (kayak or hybrid kayak-canoe) made in a plurality of nesting sections. It is covered with a waterproof fabric cover, incorporating a stabilizing and flexible keel sewn into it. The boat also has a releasably attachable and flexible coaming.

US20100196705A1
A method of repairing a composite component having a damaged area including: laying a composite patch over the damaged area; activating the shape memory polymer resin to easily and quickly mold said patch to said damaged area; deactivating said shape memory polymer so that said composite patch retains the molded shape; and bonding said composite patch to said damaged part.

US8951632B2
A composition includes a carbon nanotube (CNT)-infused carbon fiber material that includes a carbon fiber material of spoolable dimensions and carbon nanotubes (CNTs) infused to the carbon fiber material. The infused CNTs are uniform in length and uniform in distribution. The CNT infused carbon fiber material also includes a barrier coating conformally disposed about the carbon fiber material, while the CNTs are substantially free of the barrier coating. A continuous CNT infusion process includes: (a) functionalizing a carbon fiber material; (b) disposing a barrier coating on the functionalized carbon fiber material (c) disposing a carbon nanotube (CNT)-forming catalyst on the functionalized carbon fiber material; and (d) synthesizing carbon nanotubes, thereby forming a carbon nanotube-infused carbon fiber material.

US20070237942A1
The present invention provides a composite material including a substrate layer, a knit porous layer intermixed within the substrate material, and a thermoplastic layer disposed upon the porous layer. The porous layer is at least partially disposed within the thermoplastic layer. The present invention also provides a method for forming the composite material including the steps of: providing a substrate layer, providing a porous layer disposed on the substrate layer, providing a thermoplastic layer disposed on the porous layer, applying pressure and vacuum to mechanically interlock the thermoplastic layer with the porous layer; and bonding the porous layer to the substrate layer.

US10501945B2
A polymeric composite derived from a reclaimed polymeric material. The polymeric composite in particulate form can be thermally compressed into panels and other embodiments that require a component that possesses sufficient mechanical strength and moisture resistance. In certain embodiments, the panel may be utilized as one layer in a multilayered article.

DISCLOSURE OF INVENTION
[003] The novel approach to optimizing electromagnetic wave absorbing materials (EMAMs) through the innovative use of polymer nanocomposites, specifically incorporating multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs). The study highlights the complexity of predicting absorption performance in multi-layered structures, addressing this challenge byimplementing the Pareto Genetic algorithm (NSGA-II). This algorithm effectively manages nonlinear problems and optimizes the design by maximizing performance while maintaining essential parameters.

[004] The Key innovations include the development of a two-layered nanocomposite structure that achieves a remarkable reflection loss (RL) of -21 dB across the entire X-band, absorbing 99.7% of X-band radiation.

[005] The integration of GNPs enhances thermal stability, contributing to the composite's overall performance. The innovation demonstrates that combining advanced optimization techniques and additive manufacturing can significantly improve EMAM capabilities, making these materials suitable for practical applications in computer and aircraft systems.

[006] The innovation presented in this research lies in developing a composite absorber made from Multi-Walled Carbon Nanotubes (MWCNTs) and Polypropylene (PP) through an in-situ polymerization process. This novel composite demonstrates exceptional microwave absorption capabilities, achieving effectiveness values as high as -12.5 dB. The study highlights the significant increase in dielectric loss with higher MWCNT content, indicating a strong correlation between conductivity and microwave absorption characteristics.

[007] The composite's lightweight nature and low mass fraction of carbon make it an economically advantageous option, especially when combined with a glass fibre/epoxy foundation. Furthermore, the optimized composition of polymer nanocomposite enhances its electromagnetic properties, making it suitable for energy storage applications.

[008] The engineered hybrid nanocomposite allows precise control over microwave absorption within specific frequency ranges, opening up potential applications in electromagnetic interference (EMI) shielding and related technologies. The invention showcases a significant advancement in materials science, offering a practical solution for effective microwave absorption.

[009] The invention introduces a groundbreaking graphene-based polymer nanocomposite specifically engineered for electromagnetic shielding and flame retardancy in electric vehicle (EV) battery housings.

[0010] This innovative material combines a polymer matrix, such as polyimide or epoxy resin, with graphene nanoplatelets (GNPs) and hybrid fillers like carbon nanotubes or boron nitride, resulting in exceptional electrical conductivity and EMI shielding effectiveness exceeding 60 dB across a broad frequency spectrum.

[0011] Integrating flame-retardant additives, including phosphorus-based compounds or metal hydroxides, provides high thermal stability and self-extinguishing capabilities. This composite's lightweight and corrosion-resistant nature allows for complex battery housing designs, presenting a durable and cost-effective design.
SUMMARY
[0012] A simplified patent disclosure summary is given to help readers comprehend the information. It states that this description is incomplete, does not emphasize crucial innovation aspects, and does not identify its scope. The main purpose of disclosure principles is to introduce them.

[0013] The present disclosure focuses on developing a shielding material for EV battery housing that emphasizes a lightweight and compact design for enhanced absorption and shielding of EM waves during extended use. It promotes sustainable EV battery housing through polymer-based nanocomposite materials, reducing dependence on conductive and absorption shielding materials to minimizethe environmental impact.

[0014] The need for innovation in shielding technologies for electric vehicle (EV) batteries is critical due to several safety and performance challenges. Key areas for improvement include thermal management and developing materials that effectively dissipate heat without trapping it to prevent thermal runaway.

[0015] The innovation contributes to creating advanced insulating materials to mitigate risks of electrical short circuits from conductive shielding layers. Innovating lighter shielding materials that maintain structural integrity to enhance vehicle efficiency.

[0016] A balanced design shielding that minimizes electromagnetic reflection to avoid interference with vehicle electronics. The approach of formulating flame-retardant materials that do not emit toxic fumes under extreme conditions.

[0017] A disclosure focuses on recyclable and durable materials that withstand environmental stresses like moisture and vibrations. A balanced approach incorporating hybrid materials, advanced insulation, and effective grounding solutions is essential to enhance safety and performance.

[0018] Additionally, the system aims to improve safety and durability, ensuring energy-efficient integrity while providing cooling benefits. It also offers adaptability to various environmental conditions, allowing customization for different climates and user preferences to optimize performance.

[0019] The disclosure outlines several objectives for reducing EM pollutionin EV systems, particularly in battery housing, by modifying the shielding materials. Key objectives include enhancing absorption performance by employing low-weight concentration polymers and doping agents.

[0020] The need for innovation in electric vehicle (EV) battery housing is highlighted by developing a real-time monitoring system for microwave absorbers' electromagnetic (EM) properties. This system addresses critical challenges such as ensuring optimal electromagnetic interference (EMI) suppression, maintaining compliance with regulatory standards, and enhancing battery safety.

[0021] By integrating embedded sensors and a control unit, the innovation allows for continuous assessment of shielding effectiveness and material integrity, detecting issues like degradation or structural damage.

[0022] The adaptive feedback loop further enhances the system by dynamically adjusting configurations or alerting for maintenance, ultimately prolonging component lifespan and optimizing shielding efficiency.

[0023] This advancement is essential for the evolution of next-generation EV technologies, emphasizing the necessity for ongoing innovation in EV battery housing.

BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The following outlines various embodiments with specific details, emphasizing that certain features can be practised with variations or less detail without affecting the overall novelty or importance of the invention. The description aims to provide a comprehensive understanding while ensuring that no element is more significant than others.

[0025] The technical solutions presented in the embodiments of this invention are more clearly illustrated by the following illustrations, which are included in the description. Acknowledging that these illustrations illustrate particular embodiments of the invention is crucial. Those proficient in the art will immediately recognise that they can generate additional drawings or variations from these without the need for inventive effort.

[0026] FIG. 1 Development of polymer nanocomposites for EV battery housing.

[0027] FIG.2 Workflow of designing multilayered structures composed of carbon filler.

DETAILED DESCRIPTION
[0028] It is important to note that the current disclosure is not restricted to construction and component arrangement specifics as outlined in the subsequent description or illustrated in the illustrations.

[0029] The current disclosure has the potential to be implemented in a variety of ways and to take on additional embodiments. Additionally, it is important to recognise that the terminology and phraseology employed in this document are intended to serve as descriptive aids and should not be interpreted as restrictive.

[0030] The terms "including," "comprising," or "having," as well as their variations, are intended to include the items enumerated below, as well as their equivalents and any supplementary items. The terms "a" and "an" refer to the presence of at least one of the referenced items rather than a quantity limitation. Additionally, the terms "first," "second," and "third," as well as similar terms, are employed in this context to differentiate one element from another rather than to indicate any degree of importance, quantity, or order.

[0031] The invention pertains to a method for electromagnetic (EM) characterization of hybrid nanocomposites, specifically focusing on assessing AC conductivity, attenuation constant, complex permittivity, and permeability within the X-band frequency range (8.2 GHz to 12.4 GHz). The method involves calculating the absorption capabilities of materials through their real and imaginary components, which fluctuate with EM wave frequency.

[0032] The key findings include the relationship between multi-walled carbon nanotube loading and the complex permittivity of polymer composites, revealing that an increase in MWCNT concentration enhances the imaginary component of permittivity up to an optimal loading beyond which energy storage capacity diminishes due to increased conductive losses. The study also highlights forming a three-dimensional conductive network within the MWCNT/polypropylene (PP) composite, which is responsible for energy dissipation primarily as heat rather than magnetic losses due to the non-magnetic nature of the materials involved.

[0033] This method provides a systematic approach to optimizing the absorption qualities of EM absorbing materials (EMAMs) by adjusting the composition of hybrid nanocomposites, as presented in FIG 1 and 2, enhancing their performance in specific frequency ranges.

[0034] The findings can be utilized to develop advanced materials with tailored electromagnetic properties for applications in stealth technology, radar, and communication systems.

[0035] The invention relates to a composite material comprising multi-walled carbon nanotubes (MWCNTs) and polypropylene (PP) that exhibits enhanced dielectric properties, electrical conductivity, and microwave absorption capabilities. The dielectric loss tangent of the MWCNTs/PP composites demonstrates a frequency-dependent increase in dielectric loss with higher MWCNT weight percentages, particularly peaking loading. This increase is attributed to interfacial polarization effects between the conductive fillers and the resin matrix, which are influenced by the concentration of MWCNTs.

[0036] The electrical conductivity of the composites also shows a significant increase with MWCNT content, reaching a maximum of 5.3 S/cm. This behaviour aligns with percolation theory, indicating that a conductive network forms when the concentration of MWCNTs exceeds a certain threshold, enhancing the material's conductivity and complicating permittivity.

[0037] Furthermore, the composites' attenuation constant and reflection loss (RL) are optimized at specific MWCNT concentrations, with the maximum RL of -10 dB observed at lower filler loading in the X-band frequency range, indicating superior microwave absorption performance. However, beyond this optimal concentration, the RL decreases, suggesting a decline in absorption capacity due to forming a more conductive network that reduces effective absorption.

[0038] The findings suggest that incorporating MWCNTs into PP improves dielectric and electrical properties and enhances microwave absorption, making these composites suitable for applications in electromagnetic interference shielding and other advanced material uses. The invention thus provides a novel approach to designing high-performance polymer composites with tailored electromagnetic properties.

[0039] The optimization of total thickness and the number of layers in epoxy/GNP/PP composite structures for X-band applications has been conducted using the NSGA II algorithm. Various multi-layered configurations (ranging from 2 to 6 layers) were analyzed, resulting in a Pareto front that illustrates the relationship between return loss (RL) and total material thickness. The microwave absorption performance of these structures was evaluated based on electromagnetic wave theory.

[0040] Among the tested configurations, a two-layered composite structure with low weight concentrations of MWCNT/PP/epoxy (1.0520 mm) and high weight loading of GNP/PP/epoxy (4.4569 mm), totalling 5.506 mm in thickness, demonstrated optimal performance with a feasible RL of -20 dB across the entire X-band frequency range, indicating a 99.7% absorption of incident radiation.

[0041] It also examined the relative permittivity of the composites, revealing that the real part of permittivity for graphene/epoxy and PU/graphene/epoxy composites remains relatively stable with frequency. In contrast, the GNP-PP-epoxy composite's permittivity varies from 3.9 to 6.2 in the X-band, peaking at a slightly higher loading of GNP. The imaginary part of permittivity showed values between 0.6 and 1.2, with a notable decrease at higher frequencies due to the inability of charge carriers to keep pace with the changing electric field.

[0042] This invention provides valuable insights into the design and optimization of composite materials for effective microwave absorption, highlighting the potential for thin-layered structures in advanced applications.
, Claims:

1. The claim is that the polymer nanocomposite material demonstrates exceptional microwave absorption capabilities, achieving significant effectiveness values and strong absorption properties even at low concentrations. This composite is considered economically advantageous and suitable for energy storage and electromagnetic interference (EMI) shielding applications due to its lightweight and practical nature.

2. The system, as claim 1, utilizes Multi-Walled Carbon Nanotubes (MWCNTs), Graphene nanoplatelets and Polypropylene (PP).

3. As claim 1 presents, the microwave attenuation constant (AC) and reflection loss (RL) of PP/MWCNT/epoxy composites are significantly influenced by the weight percentage of MWCNTs. Specifically, the AC rises as the MWCNT concentration increases, peaking lower filler loading due to enhanced permittivity and permeability. Additionally, RL increases with MWCNT concentrations up to some loading but decreases beyond this point, indicating a decline in absorption performance for higher concentrations. The study suggests optimal MWCNT levels improve microwave energy absorption, while excessive amounts reduce effectiveness.

4. The invention claims that multi-layer polymer nanocomposites incorporating multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) significantly enhance the performance of electromagnetic wave-absorbing materials (EMAMs).

5. claim 4 demonstrates that these composites exhibit exceptional thermal stability and effective radiation absorption in the X-band. They can be optimized using advanced methods, making them suitable for practical technological applications such as computers and aircraft systems.

6. The system includes the input that the relative permittivity (both real and imaginary parts) of various composites, specifically PP/epoxy and PP/GNP/epoxy, exhibits distinct behaviours in the X-band frequency range. The real permittivity of graphene/epoxy and PU/graphene/epoxy composites remains nearly constant with increasing frequency. In contrast, the GNP-PP-epoxy composite shows a variation in real permittivity from 3.9 to 6.2, peaking at certain weight loading of fillers due to enhanced electrical conductivity. The imaginary parts of permittivity for graphene composites are relatively stable, with a noted decrease at higher frequencies due to limitations in charge carrier response. Additionally, the complex permeability of graphene/epoxy composites is low due to graphene's diamagnetic properties, and dielectric resonance peaks are attributed to various physical interactions within the material.