Non-spherical particle and dielectric composite material containing same

Abstract

The present application relates to a non-spherical particle having a first dimensional size, a second dimensional size, and a third dimensional size wherein the first dimensional size is between 0.01 and 1 [mu] m, the ratio of the first dimensional size to the second dimensional size is between 1 / 10 and 1 / 1200, the third dimensional size is between the first dimensional size and the second dimensional size, wherein the non-spherical particles comprise one or more elements selected from titanium (Ti), magnesium (Mg), aluminum (Al), nickel (Ni), silver (Ag), copper (Cu), indium (In), tin (Sn), silicon (Si), boron (B), gallium (Ga), zinc (Zn), iron (Fe), germanium (Ge), bismuth (Bi), gold (Au) and manganese (Mn), and the surface of the non-spherical particles is coated with a surfactant selected from one or more of fatty acids, organosilicon compounds and combinations thereof. The invention also relates to a dielectric composite material containing the non-spherical particles and a method for regulating and controlling the dielectric property of the composite material by using the non-spherical particles.

Description

Non-spherical particles and dielectric composite material containing the same Technical Field

[0001] This application relates to the field of dielectric materials, and more particularly to non-spherical particles that can be used to control the dielectric properties of composite materials and methods for preparing the same. The application also relates to dielectric composite materials containing the non-spherical particles and methods for controlling the dielectric properties of composite materials using the non-spherical particles. Background Art

[0002] The demand for miniaturization of high-energy storage devices and radio frequency devices, such as dielectric resonator antennas (DRAs), is driving the development of dielectric materials with improved and desirable properties. Materials with increased dielectric constants and reduced dielectric losses have garnered widespread attention. The 5G era has ushered in countless new devices with higher performance and newer functionality. Advanced dielectric materials will have an immeasurable impact on future applications, including 5G healthcare, smartphone innovation, and the Internet of Things (IoT). These applications and scenarios rely heavily on antenna technology, including resonators, waveguide filters, terminals, and base station antennas. These products share common technological requirements for frequency and directional control and reconfiguration, intelligent multi-antenna beam control, and isolation reconstruction for high-speed connections.

[0003] The development of 5G technology continues to place greater and higher demands on antenna performance, including wide bandwidth, miniaturization, and low energy consumption. Meeting these demands necessitates new materials with the required dielectric constant, relaxation, and low loss tangent across a wide frequency range, as well as the ability to control dielectric properties. Consequently, methods for controlling these material parameters are essential.

[0004] Existing technologies have attempted to address this issue through various approaches, including liquid antennas, which leverage the adjustable and controllable size of liquids to dynamically adjust antenna performance. However, this approach requires a liquid storage and transport system as a carrier for the liquid, as well as a high-precision pump system to regulate the flow of the liquid. These systems occupy a considerable amount of physical space and are difficult to miniaturize. For applications with very limited space in terminals (such as mobile phones, watches, and tablets), deploying size-adjustable liquid antennas is difficult.

[0005] Another approach is to use a new liquid material without changing the original antenna structure. This material inherently offers ultra-wideband frequency response, ultra-wide operating temperature, and passive liquid heat dissipation. However, to date, no satisfactory new liquid material has been developed.

[0006] To date, polymer-ceramic composites have attracted much attention by combining low-loss polymers (such as epoxy and silicone resins) with high-dielectric-constant ceramics (such as CaCu3Ti4O12 These polymer-ceramic composites have shown promising improvements in their dielectric constants and can also achieve low losses at certain frequencies, but this formulation approach is limited because the dielectric properties achieved in the composites are a simple combination of the intrinsic dielectric properties of each component and do not provide control over dielectric relaxation.

[0007] Furthermore, adding certain metal particles as fillers to a polymer matrix can increase the dielectric constant, but with little or no increase in dielectric loss, provided the weight percentage of the metal filler remains below the concentration required to form a conductive network. Above the threshold for conductive network formation, the dielectric loss tangent increases exponentially with increasing weight percentage. Besides negatively impacting the loss tangent, these metal-polymer composites are also limited in their practicality. For example, a theoretical study calculated that silver particles dispersed in the matrix must be uniformly distributed and oriented in the same direction, something that cannot be achieved in practical composites.

[0008] There is currently no method that can simultaneously significantly increase the dielectric constant of a dielectric material, increase the degree of relaxation (if necessary), and simultaneously reduce the dielectric loss tangent.

[0009] Therefore, to meet the 5G technology requirements for wide bandwidth, miniaturization, and low energy consumption of antennas, there is a need to provide a new material that can be widely used, which can have a dielectric constant that meets the requirements across a wide frequency range, while also taking into account relaxation (in some cases) and low loss. Furthermore, there is a need to develop a method for producing new dielectric materials with controlled electromagnetic properties (including dielectric constant, dielectric relaxation, dielectric loss, etc.), preferably with good stability and low energy consumption.

[0010] Summary of the Invention

[0011] The present application provides non-spherical particles that can be used to regulate the dielectric properties of dielectric composite materials.

[0012] In one aspect, the present application provides a non-spherical particle having a first dimension, a second dimension, and a third dimension, wherein the first dimension is between 0.01-1 μm, the ratio of the first dimension to the second dimension is between 1 / 10-1 / 1200, and the third dimension is between the first dimension and the second dimension, wherein the non-spherical particle comprises one or more elements selected from titanium (Ti), magnesium (Mg), aluminum (Al), nickel (Ni), silver (Ag), copper (Cu), indium (In), tin (Sn), silicon (Si), boron (B), gallium (Ga), zinc (Zn), iron (Fe), germanium (Ge), bismuth (Bi), gold (Au), and manganese (Mn), and the surface of the non-spherical particle is coated with a surfactant, which is one or more selected from fatty acids, organosilicon compounds, and combinations thereof.

[0013] In another aspect, the present application provides a method for preparing non-spherical particles, the method comprising the step of grinding a raw material powder and a surfactant together for 1-20 hours to obtain non-spherical particles, wherein the raw material powder comprises one or more elements selected from titanium (Ti), magnesium (Mg), aluminum (Al), nickel (Ni), silver (Ag), copper (Cu), indium (In), tin (Sn), silicon (Si), boron (B), gallium (Ga), zinc (Zn), iron (Fe), germanium (Ge), bismuth (Bi), gold (Au) and manganese (Mn), and the surfactant is one or more selected from fatty acids, organosilicon compounds and combinations thereof.

[0014] In yet another aspect, the present application provides a dielectric composite material comprising the non-spherical particles according to the present application or the non-spherical particles prepared by the method according to the present application.

[0015] In another aspect, the present application provides a method for regulating the dielectric properties of a composite material, the method comprising adding non-spherical particles according to the present application or non-spherical particles prepared by the method according to the present application to a composite material matrix, wherein the dielectric property is one or more selected from dielectric constant, dielectric loss tangent and dielectric relaxation.

[0016] In yet another aspect, the present application provides use of the non-spherical particles according to the present application, or the non-spherical particles prepared by the method according to the present application, or the dielectric composite material according to the present application in preparing a dielectric component.

[0017] Abstract: By selecting specific particle constituent elements and morphology and carrying out specific modification to the surface, the application provides a method for preparing filler particles using simple preparation technology and low-cost raw materials to improve the dielectric properties of composite materials. The application describes a simple and cost-effective but widely applicable method for improving the performance of any composite material with dielectric constant and loss tangent (and dielectric relaxation in some cases) as important factors. It can be applied to the composite materials of various solid, liquid, semi-solid or liquid-solid mixed forms. In particular, the application, by adding specific filler particles in composite materials, can achieve significant and controllable improvement of dielectric constant and / or dielectric relaxation while reducing dielectric loss tangent.

[0018] Therefore, the present application provides more possibilities for the development of high-performance dielectric composites by providing a new type of non-spherical particles as fillers or additives. Specifically, the present application provides one or more of the following advantages: 1) improving the dielectric constant of the composite material; 2) improving the dielectric relaxation of the composite material; 3) reducing the dielectric loss tangent of the composite material; 4) allowing for the regulation of dielectric properties (such as dielectric constant, dielectric relaxation, and loss tangent); 5) having good stability; 6) low energy consumption; 7) low cost; 8) having a wider applicability, suitable for various types and forms of composite materials, components, and various application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present application is explained in detail through the following specific implementation methods and drawings, so that those skilled in the art can better understand the present application, but it should not be understood as limiting the scope of the present application in any way.

[0020] FIG1 shows the measured real part of the complex dielectric constant and loss tangent of a series of metal powders (irregularly shaped particles) dispersed in PEG 600 (polyethylene glycol 600) liquid to prepare composite materials.

[0021] Figure 2 shows scanning electron microscope (SEM) images of irregular spherical aluminum powder particles (Figure 2a, hereinafter referred to as "aluminum powder" or "raw aluminum powder") and aluminum flake particles (Figure 2b, hereinafter referred to as "raw aluminum flake particles").

[0022] FIG3 shows the real part of the complex dielectric constant and the loss tangent measured when the aluminum irregular spherical powder particles ( FIG2 a ) and aluminum flake particles ( FIG2 b ) of FIG2 are dispersed in PEG600 (polyethylene glycol 600) liquid to prepare a composite material.

[0023] 4 shows SEM images of aluminum flake particles obtained by milling raw aluminum powder, stearic acid (SA, surfactant) and toluene (wetting solvent) for 1 h, 2 h and 4 h according to one embodiment of the present application.

[0024] Figure 5 shows the real part of the complex dielectric constant and the loss tangent measured when the aluminum flake particles shown in Figure 4 and the raw aluminum flake particles are dispersed in PEG 600 liquid to prepare a composite material according to one embodiment of the present application (m = grinding, Alp = aluminum powder, SA = stearic acid, 1 = 1 hour grinding time, 2 = 2 hours grinding time, 4 = 4 hours grinding time, 50wt% refers to the weight content of the aluminum flake particles in the composite material).

[0025] FIG6 shows the difference in physical appearance between the fatty acid surface-modified aluminum flake particles obtained after 4 hours of grinding according to one embodiment of the present application and the raw aluminum powder in a dry powder state and when dispersed in PEG 600.

[0026] FIG7 shows a schematic diagram of the chemical structures of saturated and unsaturated LCFAs used for surface modification of aluminum flake particles according to one embodiment of the present application.

[0027] FIG8 shows the chemical structural formula of tetraethyl orthosilicate (TEOS) and its hydrolysis reaction used according to one embodiment of the present application.

[0028] FIG. 9 shows SEM images of aluminum flake particles having different silica / aluminum molar ratios according to one embodiment of the present application.

[0029] 10 shows the real part of the complex dielectric constant of aluminum flake particles having different silica / aluminum molar ratios according to one embodiment of the present application measured in dry powder form using a solid dielectric evaluation kit (DAK, see “Details and methods of measuring dielectric properties” below).

[0030] 11 shows the real part of the complex dielectric constant and the loss tangent measured when the aluminum flake particles with different silica / aluminum molar ratios shown in FIG. 9 and the raw aluminum flake particles (without silica shell layer) are dispersed in PEG 600 liquid to prepare composite materials according to one embodiment of the present application.

[0031] FIG. 12 shows a roadmap for preparing double-coated aluminum flake particles according to one embodiment of the present application.

[0032] FIG. 13 shows the m-SAlp2.5-SA4 aluminum flake particles prepared according to FIG. 12 , raw aluminum flake particles (Alf), and SAlf with a silica coating prepared from the raw aluminum flake particles according to one embodiment of the present application. 2.5 The real part of the complex dielectric constant and the loss tangent of a composite material prepared by dispersing aluminum flake particles in PEG 600 liquid.

[0033] FIG. 14 shows a schematic diagram of exemplary aluminum flake particle sizes according to one embodiment of the present application.

[0034] FIG15 shows the complex dielectric constant spectrum (real part of complex dielectric constant and loss tangent) of the solid composite material 1 obtained by adding aluminum flakes to a polymer (PS-PIP) according to one embodiment of the present application.

[0035] FIG16 shows a comparison of the real part of the dielectric constant and the loss tangent before and after adding aluminum flakes (0 and 20 wt %) to the PS+TiAlC+Alf composite material according to one embodiment of the present application.

[0036] FIG. 17 illustrates an optimized process for preparing a composite material using a liquid material according to one embodiment of the present application.

[0037] FIG. 18 shows the relationship between the dielectric properties of the liquid polymer composite 1 according to one embodiment of the present application and the change of the aluminum particle content.

[0038] FIG. 19 shows a normalized graph showing that the degree of dielectric relaxation of the liquid polymer composite 1 according to one embodiment of the present application increases with increasing aluminum filler content.

[0039] FIG. 20 illustrates a solid dielectric evaluation kit employed in accordance with one embodiment of the present application.

[0040] FIG. 21 illustrates a liquid dielectric evaluation kit employed according to one embodiment of the present application. DETAILED DESCRIPTION

[0041] In the context of describing the present application (especially in the context of the following claims), unless otherwise stated herein or clearly contradictory to the context, the terms "one / a kind" and "the / said" and similar uses should be interpreted as covering the singular and plural. Unless otherwise stated, the terms "comprising", "having", "including" and "containing" should be interpreted as open terms (that is, "including, but not limited to"), but also include partially closed or closed terms such as "essentially consisting of" and "consisting of". Unless otherwise stated, the term "and / or" means either or both. For example, "A and / or B" means only A, only B, or both A and B. Unless otherwise stated herein, the recording of numerical ranges herein is only intended to be used as a shorthand method for independently referring to each individual value falling within the range, and each individual value is incorporated into this specification as if it were independently recorded herein.

[0042] In this document, "diameter" refers to the length of a line segment passing through the center of a standard circle and intercepted by two points on the circumference of the circle; in the case of a non-standard circle or other planar shape, it refers to the equivalent diameter corresponding to the diameter of a circle with the same area.

[0043] Herein, "particle size" in the case of standard spherical particles refers to the length of a line segment intercepted by two points on the spherical surface of a straight line passing through the center of the spherical particle; in the case of non-standard spherical particles or other three-dimensional shapes, it refers to the equivalent particle size corresponding to the particle size of a spherical particle with the same volume.

[0044] Unless otherwise stated herein or the context is clearly contradictory, all methods described herein can be performed in any suitable order. Unless otherwise stated, the use of any and all examples or exemplary language (e.g., "such as") provided herein is intended only to better illustrate the present application and does not limit the scope of the present application. Any language in this specification should not be interpreted as indicating that any unclaimed element is essential for the practice of the present application.

[0045] The preferred embodiments of the present application are described herein, including the best mode known to the inventor for implementing the present application. After reading the foregoing description, variations of those preferred embodiments may become apparent to those of ordinary skill in the art. The inventors expect that skilled artisans will appropriately adopt such variations, and the inventors hope that the present application will be implemented in a manner different from that specifically described herein. Therefore, the present application includes all modifications and equivalents of the subject matter described in the appended claims as permitted by applicable law. Moreover, unless otherwise specified herein or the context clearly contradicts, the present application encompasses any combination of all possible variations of the above elements.

[0046] The present application provides a method for preparing non-spherical particles using simple processing technology and low-cost raw material powders and using the non-spherical particles to significantly increase the dielectric constant of a composite material to a desired level while reducing the dielectric loss tangent of the composite material. The present application also relates to composite materials with improved dielectric properties (e.g., dielectric constant, relaxation, and loss tangent). The present application includes novel methods for improving and controlling the dielectric properties of composite materials and manufacturing / processing non-spherical particles for improving and controlling the dielectric properties of composite materials. The composite material can be in various physical forms, including solid, liquid, semi-solid, or liquid-solid mixed forms. Non-spherical particles with specific elemental composition, morphology, and surface modification can be formulated into a variety of matrix materials (e.g., polymer matrix materials) to produce composite materials with greatly improved dielectric properties. The present application relates to the preparation of particles that can be used to formulate dielectric composite materials having a dielectric constant that is significantly increased or allows the dielectric constant to reach a desired level, allows for increased relaxation when needed, and can counterintuitively reduce the dielectric loss tangent.

[0047] The application scenarios of the present application include situations where miniaturization of electronic devices is required while maintaining low loss (for example, achieved by high dielectric constant materials), and situations related to radio frequency equipment where materials with strong dielectric relaxation may be required. The present application can also be applied to existing dielectric materials to increase the dielectric constant or reduce the loss tangent as needed (for example, in order to improve the efficiency / performance of the device). The scope of application of the present application is wide, and it is applicable to solid, liquid, semi-solid or liquid-solid mixed forms, and can be widely used in communication networks, big data, the Internet of Things, artificial intelligence, telemedicine, unmanned driving, industrial automation, data centers and other fields. For example, the product of the present application can be any dielectric composite material for energy storage and acquisition, equipment cooling, electronic circuits, sensors, actuators, high-power applications and antennas. For example, in antennas, the composite material of the present application can be used as a filler for the metal edge antenna of a smartphone to increase bandwidth and reduce device size.

[0048] Non-spherical particles

[0049] Many metals, metalloids, alloys, carbides, ceramics, and carbon-based particles can be used to increase the dielectric constant, but only a few specific metals / metalloids / alloys can also simultaneously reduce the loss tangent.

[0050] In some embodiments, the present application provides a non-spherical particle having a first dimension size, a second dimension size and a third dimension size, wherein the first dimension size is between 0.01-1 μm, the ratio of the first dimension size to the second dimension size is between 1 / 10-1 / 1200, and the third dimension size is between the first dimension size and the second dimension size, wherein the non-spherical particle contains one or more elements selected from titanium (Ti), magnesium (Mg), aluminum (Al), nickel (Ni), silver (Ag), copper (Cu), indium (In), tin (Sn), silicon (Si), boron (B), gallium (Ga), zinc (Zn), iron (Fe), germanium (Ge), bismuth (Bi), gold (Au) and manganese (Mn), and the surface of the non-spherical particle is coated with a surfactant, which is one or more selected from fatty acids, organosilicon compounds and combinations thereof.

[0051] In some embodiments, the first dimension is within a range consisting of any two of the following values ​​as endpoints: 0.01 μm, 0.02 μm, 0.03 μm, 0.04 μm, 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.0 μm. Preferably, the first dimension is between 0.05 and 0.5 μm. Preferably, the average value of the first dimension is between 0.05 and 0.5 μm, preferably about 0.1 μm.

[0052] In some embodiments, the ratio of the first dimension to the second dimension is within a range consisting of any two of the following values ​​as endpoints: 1 / 10, 1 / 15, 1 / 20, 1 / 25, 1 / 30, 1 / 35, 1 / 40, 1 / 45, 1 / 50, 1 / 55, 1 / 60, 1 / 65, 1 / 70, 1 / 75, 1 / 80, 1 / 85, 1 / 90, 1 / 95, 1 / 100, 1 / 101, 1 / 102, 1 / 103, 1 / 104, 1 / 105, 1 / 106, 1 / 107, 1 / 108, 1 / 109, 1 / 110, 1 / 111, 1 / 112, 1 / 113, 1 / 114, 1 / 115 Preferably, the ratio of the first dimension to the second dimension is between 1 / 20 and 1 / 100.

[0053] In some embodiments, the second dimension is within a range consisting of any two of the following values ​​as endpoints: 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm,

[0025] Preferably, the second dimension is between 5 and 15 μm. Preferably, the average value of the second dimension is between 5 and 15 μm, and preferably is about 10 μm.

[0054] According to the present application, the third dimension is between the first dimension and the second dimension. Specifically, the third dimension can be the same as or close to the first dimension, or the same as or close to the second dimension, or be in a range between the first dimension and the second dimension. When the third dimension is the same as or close to the first dimension, the non-spherical particles of the present application can be elongated as a whole. When the third dimension is the same as or close to the second dimension, the non-spherical particles of the present application can be flaky as a whole. In some specific embodiments, the third dimension is within a range consisting of any two of the following values ​​as endpoints: 0.01 μm, 0.02 μm, 0.03 μm, 0.04 μm, 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, 85μm m, 90μm, 95μm, 100μm, 150μm, 200μm, 250μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm, 1000μm, 1100μm, 1200μm.

[0055] Herein, particle size (e.g., primary, secondary, and tertiary dimensions) can be measured using a variety of methods, such as sieving, microscopy (imaging), sedimentation, electrical resistance, light resistance, laser diffraction, dynamic light scattering, electron microscopy, ultrasound, and specific surface area. In some embodiments, particle size is measured using electron microscopy. Particle size measurement using electron microscopy is typically accomplished by obtaining images of the particles. This method suffers from measurement errors primarily due to the size of the particle detection range. To reduce this error, measurements must be taken from multiple sides of a given pattern. Two typical methods are scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The lower measurement limit for SEM is 0.02 μm, while that for TEM is 0.001 μm. Combining an SEM with a modern image analyzer can avoid errors caused by particle counting. SEM can also reveal the three-dimensional morphology and stacking of particles. While images and photographs have a strong sense of three-dimensionality, the resolution is lower than that of TEM, making it difficult to obtain clear images of fine particles. The transmission electron microscope (TEM) is a high-resolution, high-magnification microscope that is an effective tool for measuring and observing the morphology, organization, and structure of particles. Particle size, size distribution, and morphology can be determined by evenly dispersing particles on a copper mesh with a support film and observing them under a TEM. Typically, particle size is calculated by averaging the sizes obtained from a predetermined number of randomly selected samples (e.g., 100 samples).

[0056] In some embodiments, the non-spherical particles comprise aluminum (Al).

[0057] In some embodiments, the non-spherical particles are composed of one or more selected from aluminum (Al), aluminum composites, and aluminum alloys. In some specific embodiments, aluminum flake particles have been found to reduce the loss tangent of dielectric composites in various physical forms while increasing the dielectric constant and relaxation (if desired).

[0058] In some embodiments, the aluminum alloy comprises an alloy formed by aluminum (Al) and any one or more elements selected from titanium (Ti), magnesium (Mg), nickel (Ni), silver (Ag), copper (Cu), indium (In), tin (Sn), silicon (Si), boron (B), gallium (Ga), zinc (Zn), iron (Fe), germanium (Ge), bismuth (Bi), gold (Au), and manganese (Mn). In some preferred embodiments, the aluminum alloy comprises one or more elements selected from aluminum-gallium (AlGa) alloy, aluminum-magnesium (AlMg) alloy, zinc-aluminum (ZnAl) alloy, copper-aluminum (CuAl) alloy, and aluminum-manganese (AlMn) alloy.

[0059] In some embodiments, the aluminum complex includes one or more of an aluminum-carbon complex, an aluminum-graphene complex, an aluminum-polymer complex (e.g., an aluminum-polyester complex, an aluminum-polyurethane complex, an aluminum-polyethylene complex), an aluminum-metal oxide complex (e.g., an aluminum-ferrosoferric oxide complex), and an aluminum-organic amine complex (e.g., an aluminum-hexamethylenetetramine complex).

[0060] In some embodiments, aluminum is the most preferred metal element. Nano-aluminum flakes and aluminum-containing fillers in the form of nanoparticles are the most effective material forms, and their effects can be further optimized by optional surface modification.

[0061] The non-spherical particles according to the present application may have a regular or irregular shape, such as an angular shape, an elongated shape (rod-like, stick-like or needle-like), a flat shape (flake-like), or a combination thereof. In some embodiments, the non-spherical particles are one or more selected from flake-like particles, rod-like particles, needle-like particles and dendritic particles.

[0062] Preferably, the non-spherical particles are flaky particles. As a method for measuring the planar dimensions (e.g., diameter, length, width, etc.) and thickness of flaky particles, the planar dimensions and flaky particle thickness of flaky particles can be determined based on scanning electron microscope photos (SEM photos). For example, a measurement value can be obtained based on the size of the image coordinates of the digitized image data of the SEM photos of the non-spherical particles of the present application. In addition, the average value can also be determined by the size obtained by a predetermined number of randomly selected samples (e.g., 100 samples), and the average value obtained is defined as the planar dimensions or flaky particle thickness of the flaky particles. Preferably, the flaky particles have a planar diameter of 5-60 μm and a thickness of 0.05-1 μm.

[0063] The non-spherical particles of the present application are preferably surface modified. Examples of surface modification include, but are not limited to, acid treatment and silanization. Surface acid treatment refers to the use of fatty acids and the like to prevent oxidation of the metal (e.g., aluminum) surface, which can further enhance the performance of the material. Silanization modification refers to the surface treatment of metal particles using organosilicon compounds, where the end groups of organosilicon compounds such as silanes can be selected and / or adjusted according to the chemical properties of the insulating matrix (e.g., polymer matrix). Polar matrices benefit from silanes with polar end groups (e.g., -NH2 or -OH), and non-polar matrices refer to improvements in silanes with similar compatible functional groups (e.g., propyl, octyl, or phenylethyl end groups). For example, when the end group of the silane is a propyl group, the dispersibility in low-polarity polymers (e.g., PS or PS-PIP) can be improved; when the end group of the silane is a polar end group such as an amine (-NH2) or a hydroxyl (-OH), it can be used to improve composite materials with a high-polarity matrix environment.

[0064] In some embodiments, the fatty acid is a hydrophilic carboxylic acid having a saturated or unsaturated hydrophobic aliphatic carbon chain. Preferably, the number of carbon atoms in the hydrophobic aliphatic carbon chain is within the range consisting of any two of the following values ​​as endpoints: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 36, 38, 40, 45, 50, 55, 60.

[0065] In some embodiments, the fatty acid is a hydrophilic carboxylic acid having a saturated or unsaturated hydrophobic aliphatic carbon chain of 18-22 carbon atoms.

[0066] In some embodiments, the fatty acid is selected from stearic acid, behenic acid, and combinations thereof.

[0067] In some embodiments, the organosilicon compound is a silane or siloxane compound having a saturated or unsaturated hydrophobic aliphatic carbon chain. Preferably, the number of carbon atoms in the hydrophobic aliphatic carbon chain is within the range consisting of any two of the following values ​​as endpoints: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 36, 38, 40, 45, 50, 55, 60.

[0068] In some embodiments, the organosilicon compound has at least one saturated or unsaturated hydrocarbon chain greater than 18 carbon atoms, for example, 18 Chain silane or siloxane (including but not limited to having a> C 18 chain trimethylsilane, dimethylchlorosilane, triethylsilane, tripropylsilane, ethylpropylchlorosilane, trimethoxysilane, triethoxysilane, pentamethyldisiloxane, etc.).

[0069] In some embodiments, the surface of the non-spherical particles is further coated with a silica shell. The silica shell can further reduce dielectric loss and adjust the dielectric constant. The silica shell can adjust the dielectric constant by adjusting the molar ratio of silica to the non-spherical particle body elements according to the dielectric constant desired for a specific application to increase or decrease the dielectric constant. The addition of the silica shell is particularly useful when it is necessary to prepare a material that reduces loss but does not require a high dielectric constant. In addition, the silica shell also helps to improve the physical properties of the composite material.

[0070] In some embodiments, the non-spherical particles have a silica shell, wherein the molar ratio of silica to the bulk element of the particle is within a range consisting of any two of the following values ​​as endpoints: 0.1:10, 0.2:10, 0.3:10, 0.4:10, 0.5:10, 0.6:10, 0.7:10, 0.8:10, 0.9:10, 1:10, 1.2:10, 1.4:10, 1.6:10, 1.8:10, 2:10 : 10, 7: 10, 8: 10, 9: 10, 10: 10, 11: 10, 12: 10, 13: 10, 14: 10, 15: 10, 16: 10, 17: 10, 18: 10, 19: 20, 21: 22, 23: 24, 25: 26, 27: 28, 29: 30, 30: 31, 31: 32, 32: 33, 33: 34, 35: 36, 37: 38, 39: 40, 41: 42, 43: 44, 45: 46, 47: 48, 49: 50, 51: 52, 52: 54, 53: 56, 57: 58, 59: 51, 52: 5

[0071] In some embodiments, the non-spherical particles comprise aluminum as the bulk metal of the particle, and the non-spherical particles have a silica shell, wherein the molar ratio of silica to aluminum is within the range consisting of any two of the following values ​​as endpoints: 0.1:10, 0.2:10, 0.3:10, 0.4:10, 0.5:10, 0.6:10, 0.7:10, 0.8:10, 0.9:10, 1:10, 1.2:10, 1.4:10, 1.6:10, : 10, 1: 10, 2: 10, 3: 10, 4: 10, 5: 10, 6: 10, 7: 10, 8: 10, 9: 10, 10: 10, 11: 10, 12: 10, 13: 10, 14: 10, 15: 10, 16: 10, 17: 10, 18: 10, 19: 20, 21: 22, 23: 24, 25: 26, 27: 28, 29: 30, 31: 32, 33: 34, 35: 36, 37: 38, 39: 39, 40: 41, 41: 42, 43: 44, 45: 46, 47: 48, 49: 50, 51: 52, 52: 54, 53: 56, 57: 58, 59: 51, 52: 5

[0072] Preparation of non-spherical particles

[0073] The present application provides a method for preparing filler particles having specific elemental composition, morphology and surface chemistry (as described above), which, when added to composite materials, can significantly improve dielectric properties (in a controllable / adjustable manner).

[0074] In some embodiments, the present application provides a method for preparing non-spherical particles, comprising the step of grinding a raw material powder and a surfactant together for 1-20 hours to obtain non-spherical particles, wherein the raw material powder comprises one or more elements selected from titanium (Ti), magnesium (Mg), aluminum (Al), nickel (Ni), silver (Ag), copper (Cu), indium (In), tin (Sn), silicon (Si), boron (B), gallium (Ga), zinc (Zn), iron (Fe), germanium (Ge), bismuth (Bi), gold (Au), and manganese (Mn), and the surfactant is one or more selected from fatty acids, organosilicon compounds, and combinations thereof.

[0075] Advantageously, the method comprises the step of grinding the raw material powder and the surfactant together for a time period selected from any two of the following values: 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours. In some embodiments, the method comprises the step of grinding the raw material powder and the surfactant together for 1-20, preferably 2-10, more preferably 3-9 hours.

[0076] In some embodiments, the weight ratio of the raw material powder to the surfactant is in the range of 10:1-1:10. More specifically, the weight ratio of the raw material powder to the surfactant is in the range consisting of any two of the following values ​​as endpoints: 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10.

[0077] In some embodiments, the raw material powder includes one or more of aluminum powder, aluminum composite powder, and aluminum alloy powder.

[0078] In some embodiments, the raw material powder includes aluminum powder.

[0079] In some embodiments, the fatty acid is a hydrophilic carboxylic acid having a saturated or unsaturated hydrophobic aliphatic carbon chain. Preferably, the number of carbon atoms in the hydrophobic aliphatic carbon chain is within the range consisting of any two of the following values ​​as endpoints: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 36, 38, 40, 45, 50, 55, 60.

[0080] In some embodiments, the fatty acid is a hydrophilic carboxylic acid having a saturated or unsaturated hydrophobic aliphatic carbon chain of 18-22 carbon atoms.

[0081] In some embodiments, the fatty acid is selected from stearic acid, behenic acid, and combinations thereof.

[0082] In some embodiments, the organosilicon compound is a silane or siloxane compound having a saturated or unsaturated hydrophobic aliphatic carbon chain. Preferably, the number of carbon atoms in the hydrophobic aliphatic carbon chain is within the range consisting of any two of the following values ​​as endpoints: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 36, 38, 40, 45, 50, 55, 60.

[0083] In some embodiments, the organosilicon compound has at least one saturated or unsaturated hydrocarbon chain greater than 18 carbon atoms, for example, 18 Chain silane or siloxane (including but not limited to having a> C 18 chain trimethylsilane, dimethylchlorosilane, triethylsilane, tripropylsilane, ethylpropylchlorosilane, trimethoxysilane, triethoxysilane, pentamethyldisiloxane, etc.).

[0084] In particular, coating the non-spherical particles with fatty acids and / or organosilicon compounds helps reduce composite material losses. Using saturated or unsaturated fatty acids with a chain length of 18-22 and / or organosilicon compounds with a saturated or unsaturated hydrocarbon chain greater than 18 carbon atoms can achieve better dielectric properties. Using stearic acid and / or behenic acid can achieve optimal dielectric properties.

[0085] According to the present application, the grinding can be carried out under dry conditions or wet conditions. When carried out under wet conditions, a wetting solvent can be added during the grinding process. The grinding can be carried out in any suitable grinding equipment. Preferably, the grinding is carried out in a ball mill.

[0086] In some embodiments, the method includes the step of co-grinding the raw material powder and the surfactant in a ball mill (eg, a planetary ball mill) for 2-10 hours.

[0087] In some embodiments, the weight ratio of the raw material powder to the grinding balls is 1:10-1:60. Specifically, the weight ratio of the raw material powder to the grinding balls can be within a range consisting of any two of the following values ​​as endpoints: 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, 1:60. In some embodiments, the weight ratio of the raw material powder to the raw material powder is about 1:30-1:40.

[0088] In some embodiments, the grinding is performed in the presence of a solvent selected from one or more of toluene, mineral oil, hexane, ethanol, acetone, chloroform, dioxane, diethyl ether, ethyl acetate, and combinations thereof.

[0089] In some embodiments, the milling is performed in a planetary ball mill.

[0090] In some embodiments, the method further comprises the step of forming a silica shell layer on the surface of the non-spherical particles.

[0091] The method for forming the silica shell layer on the surface of the non-spherical particles is not particularly limited, and those skilled in the art can select a suitable precursor and a corresponding method as needed.

[0092] In some embodiments, the precursor used to form the silica shell layer is one or more selected from tetraethyl orthosilicate (also known as "tetraethyl orthosilicate"), tetrapropyl orthosilicate, tetraisopropyl orthosilicate, tetrabutyl orthosilicate, tetraisobutyl orthosilicate, tetra-tert-butyl orthosilicate, tetra(methoxyethoxy)silane, sodium silicate (water glass), colloidal silica, and fumed silica.

[0093] In some embodiments, a silica shell is formed on the surface of the non-spherical particle by reacting the non-spherical particle body with a silica shell precursor (e.g., tetraethyl orthosilicate (TEOS)) in the presence of water and an optional acid / base catalyst. In this method, silica shells of varying thicknesses can be formed by adjusting the molar ratio of the silica shell precursor (e.g., TEOS) to the particle body elements. Other precursors and methods for forming the silica shell are also possible.

[0094] In some embodiments, the molar ratio of silicon in the silica shell precursor to the bulk element of the particle is within a range consisting of any two of the following values ​​as endpoints: 0.1:10, 0.2:10, 0.3:10, 0.4:10, 0.5:10, 0.6:10, 0.7:10, 0.8:10, 0.9:10, 1:10, 1.2:10, 1.4:10, 1.6:10, 1.8:10, 2:10, 2.2:10, 3:10, 4:10, 5:10, 6:10, 7:10, 8:10, 9:10, 10:10, 11:10, 12:10, 13:10, 14:10, 15:10, 16:10, 17:10, 18:10, 19:10, 20:10, 21:10, 22:10 : 10, 8: 10, 9: 10, 10: 10, 11: 10, 12: 10, 13: 10, 14: 10, 15: 10, 16: 10, 17: 10, 18: 10, 19: 20, 21: 22, 23: 24, 25: 26, 27: 28, 29: 30, 30: 31, 31: 32, 33: 34, 35: 36, 37: 38, 39: 40, 41: 42, 43: 44, 45: 46, 47: 48, 49: 50, 51: 52, 52: 54, 53: 56, 57: 58, 59: 51, 52: 5

[0095] In some embodiments, the non-spherical particles contain aluminum as the bulk element of the particles, and the molar ratio of silicon to aluminum in the silica shell precursor is within a range consisting of any two of the following values ​​as endpoints: 0.1:10, 0.2:10, 0.3:10, 0.4:10, 0.5:10, 0.6:10, 0.7:10, 0.8:10, 0.9:10, 1:10, 1.2:10, 1.4:10. : 10, 6:10, 6.5:10, 7:10, 7.5:10, and 8:10. In some embodiments, the molar ratio of silicon to aluminum in the silica shell precursor is in the range of 0.4:10 to 5:10, preferably in the range of 0.4:10 to 2:10.

[0096] For example, when the particle body contains aluminum and TEOS is used as the silica shell precursor, the molar ratio of TEOS to aluminum can be 0.4:10-5:10. When the molar ratio of TEOS to aluminum is greater than or equal to 1:10, a complete silica shell can be formed without an exposed metal surface. The thickness of the silica shell is negatively correlated with the increase in dielectric constant. However, non-spherical particles with silica shells can further reduce the loss tangent of the composite material. In other words, by adjusting the thickness of the silica shell, the dielectric constant of the composite material can be controllably increased while reducing the loss tangent of the composite material. In addition, the silica shell also helps to improve the physical properties of the composite material.

[0097] According to one embodiment of the present application, the surface treatment of the non-spherical particles is performed by combining surface modification with surfactant and formation of a silica shell. Preferably, the surface modification is first performed by adding a surfactant (e.g., a fatty acid, an organosilicon compound, or a combination thereof) during the grinding process, and then a silica (SiO2) coating is formed on the surface thereof. The coating can control the level of dielectric constant increase while maintaining (or even improving) the loss reduction capability. This is very useful when a low-loss material is required but the dielectric constant is not significantly increased.

[0098] Aluminum flake particles are commonly used in the pigment and paint industry. Although aluminum flake particles are inexpensive and commercially available, the use of the new method according to the present application to prepare aluminum flake particles can ensure that their purity, surface material, repeatability and processing conditions can provide the desired dielectric properties for the composite material. The study found that careful control of the grinding conditions can produce aluminum flake particles that provide optimal dielectric properties when formulated into a composite material. These conditions include grinding time, the type and weight percentage of surfactant, the ratio of grinding balls to raw powder, and whether the grinding process is dry or wet (i.e., in a solvent or not).

[0099] Dielectric composite materials

[0100] This article describes the preparation and function of specific metal particles (e.g., aluminum flake particles) of specific elements, shapes, sizes, and surface chemistries that not only significantly increase the dielectric constant (to a desired level) but also, counterintuitively, significantly reduce the loss tangent. Using the non-spherical particles of the present application, low-loss dielectric composites with desired dielectric constants and / or relaxation levels can be produced by simply controlling the weight percentage of the non-spherical particles and the thickness of the coating on the surface of the non-spherical particles.

[0101] Therefore, the present application also provides a dielectric composite material comprising the above-mentioned non-spherical particles according to the present application. The dielectric composite material has a controlled increase in dielectric constant, a reduced loss tangent, an increased dielectric relaxation and / or improved other physical properties. The dielectric composite material can be solid, liquid, semi-solid and / or a liquid-solid mixed state. The composite material can be used in various occasions requiring specific or customized dielectric properties, such as energy storage and collection, equipment cooling, electronic circuits, sensors, actuators, high-power applications and antennas.

[0102] The present application does not particularly limit the matrix material of the dielectric composite material, and can be metal, ceramic, polymer, or any combination thereof. Generally speaking, any form of matrix material is suitable for the present application, as long as it can be mixed with the non-spherical particles of the present application and does not adversely react with the non-spherical particles.

[0103] In some embodiments, the matrix material of the dielectric composite is a polymer, wherein the non-spherical particles are dispersed in the polymer matrix.

[0104] In some embodiments, the polymer can be one or more selected from polyethylene glycol, polyvinyl chloride, polystyrene, polyisoprene, polyethylene oxide, polypropylene oxide, polytetrafluoroethylene, polyvinylidene fluoride, poly(vinylidene fluoride-co-trifluoroethylene), polyethylene, polypropylene, polyester, polyurethane, polyamide, polyimide, polyetheretherketone, and copolymers thereof. Those skilled in the art may also use other suitable polymer types as needed.

[0105] In some embodiments, the non-spherical particles are present in the dielectric composite material in an amount less than 80 wt % based on the total weight of the dielectric composite material. Preferably, the weight content of the non-spherical particles in the dielectric composite material is within a range consisting of any two of the following values ​​as endpoints: 0.5 wt %, 1 wt %, 2 wt %, 3 wt %, 4 wt %, 5 wt %, 6 wt %, 7 wt %, 8 wt %, 9 wt %, 10 wt %, 15 wt %, 20 wt %, 25 wt %, 30 wt %, 35 wt %, 40 wt %, 45 wt %, 50 wt %, 55 wt %, 60 wt %, 65 wt %, 70 wt %, 75 wt %, 80 wt %.

[0106] In some preferred embodiments, the non-spherical particles are present in the dielectric composite in an amount of 5 to 60 weight percent based on the total weight of the dielectric composite.

[0107] In some embodiments, the dielectric composite material further comprises silica particles. The inventors of the present application have found that adding silica (SiO2) particles to the non-spherical particles according to the present application can reduce the dielectric loss of the composite material when formulated into a composite material, and can increase or decrease the dielectric constant in a small range. This is very useful when manufacturing materials that need to reduce losses but do not require high dielectric constant materials, and can also be used to customize or fine-tune the dielectric properties of the composite material as needed. The particle size of the silica (SiO2) particles can be nanometer-scale or micrometer-scale, for example, within the range consisting of any two of the following numerical values ​​as endpoints: 1nm, 10nm, 50nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1μm, 5μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm. In one embodiment, the particle size of the silicon dioxide (SiO2) particles is in the range of 1 nm to 100 μm, preferably in the range of 5-80 μm. Prior art shows that when SiO2 particles are used alone without the non-spherical particles of the present application, dielectric loss and dielectric constant are generally reduced simultaneously. However, mixing the non-spherical particles of the present application with SiO2 particles can increase the dielectric constant to a certain extent while reducing dielectric loss, which is surprising.

[0108] The present application also provides a method for preparing a dielectric composite material, comprising adding the non-spherical particles according to the present application and optional silica particles into a composite material matrix.

[0109] Dielectric properties control method

[0110] This application describes how metal particles of specific elements, shapes, and sizes, when used in dielectric composites, can not only significantly increase the dielectric constant but also significantly reduce the dielectric loss. Particularly advantageously, this application allows for the dielectric constant, dielectric relaxation, and / or dielectric loss of the dielectric composite to be manipulated as needed, for example, by adjusting the preparation process for the non-spherical particles and / or adjusting the weight percentage of the non-spherical particles in the dielectric composite.

[0111] To the best of the inventors' knowledge, no other method has been found to reduce the losses of composite materials, particularly by significantly increasing the dielectric constant and / or enhancing dielectric relaxation, other than the present technique. This discovery is directly related to the choice of metal / metalloid element (e.g., aluminum was found to have the best performance) and the shape of the metal / metalloid particles (e.g., flake-shaped particles were found to have significantly improved performance over spheres or irregular spheres), which can be used to control the dielectric properties of the composite materials.

[0112] In some embodiments, the present application provides a method for regulating the dielectric properties of a composite material, the method comprising adding non-spherical particles according to the present application or adding non-spherical particles prepared by the method according to the present application to the composite material, wherein the dielectric property is one or more selected from dielectric constant, dielectric loss tangent and dielectric relaxation.

[0113] In some embodiments, the method includes regulating the dielectric properties by adjusting the content of non-spherical particles in the composite material.

[0114] In some embodiments, the method includes regulating the dielectric properties by adjusting the content of specific elements in the non-spherical particles.

[0115] In some embodiments, the method includes regulating the dielectric properties by adjusting the content of aluminum in the non-spherical particles.

[0116] In some embodiments, the method includes regulating the dielectric properties by adjusting the content and / or type of fatty acid, organosilicon compound, or a combination thereof on the surface of the non-spherical particles.

[0117] In some embodiments, the method includes tuning the dielectric properties by adjusting the thickness of the silica shell of the non-spherical particles. The silica shell thickness can be adjusted by the molar ratio between the silica shell precursor compound and the elements in the bulk of the non-spherical particles.

[0118] By adding the non-spherical particles of the present application, the dielectric constant of the dielectric composite material can be significantly increased or increased to a desired level, and its relaxation can be increased if necessary, and counterintuitively, its dielectric loss tangent can be reduced.

[0119] In some embodiments, the present invention can control the dielectric constant and relaxation degree of dielectric composite materials by controlling the weight percentage of non-spherical particles (e.g., aluminum flake particles). This method can be used to improve the dielectric properties (including dielectric constant and loss tangent) of any composite material, or to introduce dielectric relaxation into a material to achieve a frequency-dependent dielectric constant. Aluminum flake fillers have been found to be most effective in regulating dielectric properties, and the production process is simple, cost-effective, and widely applicable.

[0120] Therefore, the dielectric property control method according to the present application may include one or more of the following methods: 1) Adjusting the amount of non-spherical particles added. The weight content of non-spherical particles is positively correlated with the increase in the dielectric constant of the composite material and affects the dielectric relaxation of the composite material. 2) Adjusting the composition of the non-spherical particles. Non-spherical particles containing different metal / metalloid elements can bring about different degrees of dielectric constant improvement. Adding particles containing aluminum as the main element to the composite material can achieve the most significant increase in the dielectric constant. 3) Adjusting the morphology of the non-spherical particles. Flaky particles can further reduce the dielectric loss of the composite material. Preferably, the flaky particles have a planar diameter of 5-60 μm and a thickness of 0.05-1 μm. 4) Adjusting the processing method of the non-spherical particles. Surface modification of the non-spherical particles using fatty acids will help reduce dielectric loss. Coating the non-spherical particles with a silica shell can control the increase in the dielectric constant of the composite material, further reduce dielectric loss and improve physical properties.

[0121] Those skilled in the art are capable of comprehensively adjusting the above four methods to obtain various desired composite materials and desired composite material properties.

[0122] In addition, the inventor of the present application has also found that according to the non-spherical particles of the present application, silicon dioxide (SiO ) particle is added, when being mixed with composite material, the dielectric loss of composite material can be reduced, and dielectric constant can be increased or reduced in a small range. This is very useful when manufacturing needs to reduce loss but does not need high dielectric constant material, and can also be used to customize or fine-tune the dielectric properties of composite material as required. Therefore, according to the dielectric properties control method of the present application, it can also be included in that silicon dioxide (SiO ) particle is then added to the step of being mixed with composite material matrix, or comprises non-spherical particles and silicon dioxide (SiO ) particle is added to the step of being mixed with composite material matrix simultaneously. The particle size of the silica (SiO2) particles can be nanometer-scale or micrometer-scale, for example, within a range consisting of any two of the following values ​​as endpoints: 1 nm, 10 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm. In one embodiment, the particle size of the silica (SiO2) particles is in the range of 1 nm to 100 μm, preferably in the range of 5-80 μm. The amount of silica (SiO2) particles used will also affect the change in dielectric properties, so the dielectric properties can be adjusted to meet the needs of a specific application by adjusting the ratio of silica (SiO2) particles to non-spherical particles. In addition, the addition of silica particles can also help improve other physical properties of the composite material.

[0123] Therefore, the present application provides a novel, universal method for controlling the dielectric properties of composite dielectric materials, which achieves a controlled increase in the dielectric constant (eg, based on the weight % of filler) and a simultaneous reduction in dielectric loss compared to the prior art.

[0124] application

[0125] The present application can cover different application scenarios and improve various existing dielectric composite materials, especially can be used to improve dielectric constant / dielectric relaxation and reduce dielectric loss in various scenarios. By increasing the dielectric constant, device performance can be improved or the device can be miniaturized; by reducing dielectric loss, device energy consumption can be reduced. Therefore, the present application also provides the use of non-spherical particles or dielectric composite materials containing the same in the preparation of dielectric components. The non-spherical particles and their composite materials of the present application can be widely used in communication networks, big data, the Internet of Things, artificial intelligence, telemedicine, unmanned driving, industrial automation, data centers and other fields.

[0126] In some embodiments, the dielectric component can be one or more selected from the following: antennas, radomes, polymer-ceramic composite dielectric components, capacitors, printed circuit boards, sensors, actuators, resonators, waveguide filters, and other dielectric components.

[0127] In some embodiments, the non-spherical particles of the present application can be used as fillers in antenna dielectrics, improving the dielectric properties of the material to achieve miniaturization and broadband response of the antenna. Examples of antennas include, but are not limited to, DRAs, lens antennas, and mobile phone frame antennas.

[0128] In some embodiments, the non-spherical particles of the present application can be used as fillers in existing polymer-ceramic composite materials to further improve material properties and achieve higher dielectric constants and lower losses.

[0129] In some embodiments, the non-spherical particles of the present application can be used as dielectric materials in capacitors to increase energy density.

[0130] In some embodiments, the non-spherical particles of the present application can be added to printed circuit board (PCB) materials (eg, FR4-type materials) to further improve the material properties and achieve higher dielectric constants and lower losses.

[0131] Example

[0132] The following examples are illustrative and non-limiting of the products and methods described herein. Suitable modifications and adjustments of the various conditions, formulations, and other parameters commonly encountered in the art, as well as modifications and adjustments that are obvious to those skilled in the art in light of this disclosure, are within the spirit and scope of this application.

[0133] The raw materials used in the following examples can all be synthesized by known methods or obtained through commercial channels. The synthesis techniques and conditions used are also easily understood by those skilled in the art. The obtained dielectric compositions all meet the specifications of electronic chemicals.

[0134] Example 1 Effect of particle morphology and element type on dielectric properties

[0135] Various metal powders (irregular spherical particles with an average particle size range of 1-50 μm), including titanium, magnesium, aluminum, nickel, silver, copper, indium, tin, silicon, boron, gallium, zinc, iron, germanium, bismuth, gold, and manganese, can improve the dielectric constant when formulated into composite materials. Figure 1 shows the measured real part of the complex dielectric constant and loss tangent of a series of metal powders (irregularly shaped particles) dispersed in PEG600 (polyethylene glycol 600) liquid to formulate composite materials.

[0136] As can be seen from Figure 1, aluminum powder provides the largest dielectric constant compared to other metal powders, but the loss tangents of various metal powders are very close or almost the same.

[0137] Figure 2 shows SEM images of aluminum irregular spherical powder particles (Figure 2a, average particle size 1-50μm) and aluminum flake particles (Figure 2b, thickness between 0.1 and 1μm, planar diameter between 5 and 60μm). The dielectric properties of these two particles were measured when they were dispersed in PEG 600 (polyethylene glycol 600) liquid to form a composite material. Figure 3 shows the real part of the complex dielectric constant and loss tangent measured when composite materials were prepared by adding aluminum particles of different forms to the PEG 600 liquid. PEG 600 is originally a low dielectric constant material with no relaxation, but the dielectric constant increases after the addition of aluminum. As can be seen from Figures 2 and 3, compared to aluminum irregular spherical powder particles, aluminum flake particles provide a significantly higher dielectric constant and significantly lower dielectric loss, even at a lower weight percentage. In other words, aluminum flakes are more effective than aluminum powder in improving the dielectric properties of the composite material. In particular, aluminum flakes provide a higher dielectric constant while reducing losses, something that aluminum powder cannot provide.

[0138] Similar trends in dielectric properties were observed when commercially available flake metal particles (thicknesses ranging from 0.1 to 1 μm and planar diameters ranging from 5 to 60 μm) were dispersed in PEG 600 (polyethylene glycol 600) liquid to form composites. The flake metal particles exhibited significantly greater dielectric constants and lower dielectric losses than the non-flake powders of the same element. Furthermore, flake particles composed of 100% aluminum were found to provide the best results.

[0139] Although aluminum has been shown to have the best dielectric properties, other metallic elements / alloys have also been shown to be effective and, in some cases, can achieve similar results, particularly aluminum alloys such as aluminum-gallium (AlGa) alloys.

[0140] In this example, a particle shape / morphology that maximizes the effect of the metal element is used, namely, flake-shaped particles, which are more effective than spherical particles of the same element.

[0141] Example 2 Effect of surface modification on dielectric properties

[0142] When preparing composite materials with enhanced dielectric constant and reduced loss, it is necessary to consider not only the selection of metal elements as fillers and the shape of the filler particles, but also the surface chemical properties of the particles. In this example, aluminum flake particles are used as an example to study the effect of particle surface modification on the dielectric properties of composite materials. Aluminum flake particles are commonly used in the pigment and paint industries. Although aluminum flake particles are inexpensive and commercially available, this application proposes a new method for preparing aluminum flake particles to ensure that their purity, surface chemistry, repeatability and processing conditions can provide the desired dielectric properties for the composite material. In this example, aluminum flake particles are prepared by processing raw aluminum powder, surfactant and wetting solvent in a planetary ball mill.

[0143] The equipment and raw materials used are as follows:

[0144] Ball mill: Planetary Mono Mill poverisette 6 classic series (from Fritsch).

[0145] Grinding bowl: Hard stainless steel bowl (from Fritsch)

[0146] Grinding balls: stainless steel grinding balls (from Fritsch)

[0147] Aluminum powder: As shown in Figure 2a, the average particle size is 1-50μm

[0148] Surfactant: stearic acid

[0149] Wetting solvent: toluene

[0150] The sample surface was coated with gold using a Quorum S150T ES sprayer, and the powder morphology was analyzed using a Hitachi S-4800 cold field emission scanning electron microscope (FE-SEM).

[0151] Figure 4 shows SEM images of aluminum flake particles obtained by grinding raw aluminum powder, stearic acid (SA, surfactant) and toluene (wetting solvent) at a grinding speed of 200-300 rpm for 1h, 2h and 4h, wherein the weight ratio of raw aluminum powder to stearic acid is 4:1, and the weight ratio of grinding balls to raw aluminum powder is 40:1. It can be seen that within 1h, the aluminum powder was flattened into very large flakes with a particle size of 130μm. After 2h, the large flakes showed a reduced average particle size and thickness. After a grinding time of 4h, small flakes with a particle size of approximately 4-12μm were obtained, and the particle size distribution was also greatly improved. The aluminum flake particles obtained by the method of the present application under the condition of grinding for 4 hours are very different from the raw aluminum flake particles in physical morphology, whether in a dry state or when dispersed in PEG600.

[0152] Figure 5 shows the real part of the complex dielectric constant and loss tangent measured when the aforementioned aluminum flake particles and raw aluminum flake particles (thickness between 0.1 and 1 μm, planar diameter between 5 and 60 μm) were dispersed in a PEG 600 liquid to prepare composite materials. Figure 5 illustrates the effect of grinding time on the dielectric properties of the aluminum flake particle / PEG 600 composites. "m-Alp-SA1 50 wt%" refers to a composite material obtained by adding 50 wt% aluminum flake particles, obtained by grinding aluminum powder with stearic acid for 1 hour, to a PEG 600 liquid (m = grinding, Alp = aluminum powder, SA = stearic acid, 1 = 1 hour grinding time), and so on.

[0153] Figure 6 shows the macroscopic morphology of the raw aluminum powder and the fatty acid surface-modified aluminum flake particles obtained after 4 h of grinding in the dry powder state and when dispersed in PEG 600, and the difference in their physical appearance can be seen.

[0154] Without wishing to be bound by theory, it is believed that the surface of the aluminum flake particles prepared according to the method of the present application is coated with fatty acids, which play a role in reducing loss performance. Fatty acids (R-CO2H) include a hydrophilic carboxylic acid group and a hydrophobic aliphatic carbon chain, the length of which can vary and can be saturated or unsaturated. The length of the hydrophobic aliphatic carbon chain in the fatty acid can be short chain (≤5 carbons, also known as short chain fatty acids or SCFA), medium chain (6-12 carbons, also known as medium chain fatty acids or MCFA), long chain (13-21 carbons, also known as long chain fatty acids or LCFA) or very long chain (≥22 carbons, also known as very long chain fatty acids or VLCFA). Figure 7 shows a schematic diagram of the chemical structure of several saturated and unsaturated LCFAs.

[0155] The study found that treating aluminum flake particles with saturated or unsaturated fatty acids with carbon chain lengths of approximately 18-22 carbon atoms can achieve relatively better dielectric effects, with stearic acid (SA) and behenic acid (BA) providing the best dielectric results. In addition, using other surface modifiers with similarly large carbon chains (such as trimethoxysilane with a carbon chain greater than 18 carbon atoms) can also produce the same or similar effects as fatty acids.

[0156] Example 3 Effect of silicon dioxide shell on dielectric properties

[0157] Very high dielectric constant may be very useful for certain applications, but sometimes it is also necessary to control the level of dielectric constant improvement while keeping loss reduction. The present embodiment is an example study of the influence of silicon coating on the dielectric properties of composite materials by coating the particle surface with aluminum flake particles. It is found that the level of dielectric constant improvement can be controlled by using silicon dioxide (SiO2) shell coating particles of different thicknesses. In the present embodiment, tetraethyl orthosilicate (TEOS) is used as a silicon dioxide precursor. After adding water (optionally using an acid / base catalyst), tetraethyl orthosilicate (TEOS) can be easily converted into silicon dioxide. Through a series of condensation reactions, TEOS can form a solid similar to a mineral by forming Si-O-Si bonds (silicon dioxide) on the metal particle surface. Figure 8 shows the chemical structural formula and hydrolysis-condensation reaction of tetraethyl orthosilicate (TEOS).

[0158] The specific preparation process and parameters are as follows:

[0159] In a 500 ml round-bottom flask, raw aluminum flakes (Alf, as shown in FIG2 b , 5 g, 185.32 mmol, thickness between 0.1 and 1 μm, plane diameter between 5 and 60 μm) were suspended in ethanol (250 ml, anhydrous ethanol, purity 99%).

[0160] TEOS was added and the thickness of the silica shell layer was adjusted by the amount of TEOS added (eg, 9.65 grams, 10.33 ml, 46.33 mol, corresponding to a 2.5:10 molar ratio of TEOS:Alf; 4.13 ml, 18.48 mol, corresponding to a 1:10 molar ratio of TEOS:Alf).

[0161] The mixture was heated to 40° C. and NH 4 OH (28% in water) was added dropwise / slowly until a pH of 8-10 was reached.

[0162] The mixture was stirred for at least 6 hours, then poured into a 1 L Erlenmeyer flask to allow the silica-coated particles to settle at the bottom. The supernatant was carefully decanted (without removing any particles). Another portion of ethanol (250 ml) was added, the mixture was shaken thoroughly to allow it to settle, and the supernatant was decanted again. This washing process was repeated once more.

[0163] The particles were first dried at 60°C to remove residual ethanol and then significantly dried at 60°C under vacuum.

[0164] The product was isolated and dried.

[0165] Aluminum flake particles with different silica / aluminum molar ratios were prepared, and their SEM images are shown in Figure 9. Here, Alf refers to untreated raw aluminum flake particles (thickness between 0.1 and 1 μm, planar diameter between 5 and 60 μm) without a silica shell (Figure 9a); SAlf refers to untreated raw aluminum flake particles (thickness between 0.1 and 1 μm, planar diameter between 5 and 60 μm), without a silica shell (Figure 9a); 0.4 SAlf1 refers to a silica-coated aluminum flake particle with a silica-to-aluminum molar ratio of 1:10 ( FIG. 9 c , showing that the surface of the metal aluminum flake is completely covered with a silica shell); SAlf2 refers to a silica-coated aluminum flake particle with a silica-to-aluminum molar ratio of 1:10 ( FIG. 9 c , showing that the surface of the metal aluminum flake is completely covered with a silica shell); 2.5 SAlf5 refers to silica-coated aluminum flake particles with a silica to aluminum molar ratio of 5:10 ( FIG. 9e , showing that the surface of the metal aluminum flake is completely covered with an even thicker silica shell).

[0166] FIG. 10 shows aluminum flake particles (SAlf) with different silica / aluminum molar ratios. 0.4-5 ) in dry powder form using the Solid Dielectric Evaluation Kit (DAK, see "Dielectric Properties Measurement Details and Methods" section below). Figure 10 shows the effect of the thickness of the silica coating on the aluminum flake particles on the dielectric constant. The thickest silica coating is formed at a silica / aluminum molar ratio of 5:10, at which point the dielectric constant is only ε' = 10. As the silica / aluminum molar ratio decreases, the thickness of the silica shell decreases, but much higher dielectric constants can be achieved. This surface coating method allows the desired increase or decrease in dielectric constant to be achieved simply by adjusting the amount of silica precursor (e.g., TEOS) used to produce a thin or thick shell.

[0167] FIG11 shows the real part of the complex dielectric constant and the loss tangent measured when aluminum flake particles with different silica / aluminum molar ratios and raw aluminum flake particles (without silica shell) were dispersed in PEG 600 liquid to prepare composite materials. For aluminum flake particles with silica shells, as the thickness of the silica shell changes, the dielectric constant of the composite material shows the same trend as the dielectric constant change observed in the form of aluminum flake particles in the form of dry powder in FIG10, that is, as the thickness of the silica shell decreases, the dielectric constant increases. FIG11 also shows that when the molar ratio of silica to aluminum is greater than 2.5:10 (see SAlf in FIG11), the dielectric constant of the composite material increases. 2.5and SAlf5), the dielectric constant of the composite material obtained is even lower than that of the composite material prepared from aluminum flake particles without a silica shell (i.e., untreated Alf). In addition, it can be seen from Figure 11 that an increase in the thickness of the silica shell will lead to a decrease in the loss tangent, except for SAlf 0.4 In addition to having a loss tangent similar to that of the untreated Alf, SAlf1, SAlf 2.5 、SAlf 0.4 Provides successively lower loss tangents.

[0168] This example demonstrates that the performance of the material can be further improved through customized processing (such as adding a silica shell layer) by using commercially available mass-produced aluminum flakes (such as nano-aluminum flakes).

[0169] Example 4 Effect of Combination of Surface Modification and Silica Shell on Dielectric Properties

[0170] As described above, aluminum flake particles produced by surface-modifying aluminum powder with fatty acids (e.g., SA stearate) provide iridescent metallic flakes with optimal morphology and can significantly increase dielectric constant while reducing dielectric losses. Coating untreated raw aluminum flake particles with silica shells of varying thickness can be used to control the increase in dielectric constant to a desired level while maintaining the characteristics of reduced dielectric loss.

[0171] This example combines the two aforementioned techniques, using irregular spherical aluminum powder particles as raw material to prepare aluminum flake particles with a fatty acid coating, and then coating their surfaces with a silica shell layer. Figure 12 shows the overall scheme for preparing double-coated aluminum flake particles. Figure 13 shows the real part of the complex dielectric constant and loss tangent measured when the prepared m-SAlp2.5-SA4 aluminum flake particles were dispersed in a PEG 600 liquid to prepare a composite material, and compared them with the results of using untreated raw aluminum flake particles and SAlf with a silica coating prepared from untreated raw aluminum flake particles. 2.5 The real part of the complex dielectric constant and the loss tangent of the composite material of aluminum flake particles prepared in PEG 600 liquid and PEG 600 itself are compared, where 30wt% refers to the weight content of the aluminum flake particles in the composite material. As shown in Figure 13, the aluminum flake particles with a double coating, namely m-SAlp2.5-SA4, provide the highest and controlled dielectric constant (ε'<100) and the lowest dielectric loss. It can be seen that the addition of the silica shell layer can produce a positive effect by combining with the metal particles of the specific elements and shapes (and with specific surface treatments) according to the present application, not only reducing the dielectric loss, but also increasing the dielectric constant in a controllable manner, which is different from the effect of reducing the loss and also reducing the dielectric constant by adding silica particles observed in the prior art.

[0172] FIG14 is a schematic diagram showing the size of the non-spherical particles prepared in this example.

[0173] Example 5 Preparation of dielectric composite material

[0174] Solid-State Composites 1-Low-Loss, Frequency-Independent Dielectric Materials

[0175] In a 250 ml round-bottom flask, 10 g of the total mass of polystyrene-polyisoprene and aluminum flakes (up to 60 wt%) were dissolved / suspended in toluene (30 ml) and stirred at 80°C for 1 hour under an inert atmosphere. The mixture was ultrasonicated at 80°C for 1 hour, and then the solvent was dried under vacuum. The resulting composite mixture was then ground into a fine powder using a laboratory-grade grinder. The fine solid powder was transferred to a stainless steel mold (25 mm diameter) and pressed at a pressure of up to 5 tons. The pressed material was removed from the mold and prepared for dielectric measurements.

[0176] Figure 15 shows the complex dielectric constant spectrum of the solid composite material 1 obtained by adding aluminum flakes to the polymer (PS-PIP). The real part of the dielectric constant increases with the mass fraction of aluminum flakes; the loss tangent does not change significantly within the accuracy of the measuring instrument (0.01).

[0177] As can be seen, by increasing the weight percentage of aluminum flakes in the composite, the dielectric constant of a solid polymer (polystyrene-polyisoprene copolymer, PS-PIP), which originally has no frequency dependence, can be manipulated. The addition of aluminum flakes significantly increases the dielectric constant of the composite. For example, at a 60% by weight aluminum flake filler content, the dielectric constant increases from approximately 2.6 to approximately 70 (an increase of approximately 27 times). The loss tangent of all the composites shown in Figure 15 is very low, with the loss tangent of the pure polymer matrix being <0.001.

[0178] Solid-State Composite Materials 2 - Composite Materials with Frequency-Dependent Dielectric Constants (Dielectric Relaxation)

[0179] In a 250ml round-bottom flask, polystyrene (3g), titanium aluminum carbide (5g) and aluminum flakes (2g) were dissolved / suspended in toluene (30ml) and stirred at 80°C for 1 hour under an inert atmosphere. The mixture was then ultrasonicated at 80°C for 1 hour, and the solvent was then dried in vacuo. The resulting composite mixture was then ground into a fine powder using a laboratory-grade grinder. The fine solid powder was then transferred to a stainless steel mold (25mm in diameter) and pressed at 15 tons of pressure. The pressed material was removed from the mold and prepared for measurement.

[0180] Figure 16 shows a comparison of the real part of the dielectric constant and the loss tangent before and after the addition of aluminum flakes (0 and 20 wt%) to the PS+TiAlC+Alf composite. It can be seen that the addition of 20 wt% aluminum flakes to the solid composite with a frequency-dependent dielectric constant (dielectric relaxation) doubles the dielectric constant while significantly reducing the loss by 65%.

[0181] Liquid Composites 1 - Composites with Frequency-Dependent Dielectric Constants (Dielectric Relaxation)

[0182] In a 40 ml sample bottle with a PTFE-lined cap, polyethylene oxide (MW 300,000), propylene carbonate (0.8 ml) and N-methylacetamide (2 g) were dissolved in toluene and stirred vigorously at 80°C until a clear, homogeneous, viscous liquid was obtained. Aluminum flakes (up to 60 wt%) were added to the liquid polymer composite and the mixture was mixed at 2000 rpm using an overhead stirrer equipped with a blade stirrer tool for 0.5 hours. Figure 17 shows the optimized process for preparing composites using liquid materials.

[0183] Figure 18 shows the relationship between the dielectric properties of liquid polymer composite 1 and the content of aluminum particles. As the aluminum content increases, the dielectric constant increases. The more aluminum is added, the more significant the loss reduction is.

[0184] FIG. 19 shows a normalized graph showing the increase in the degree of dielectric relaxation of the liquid polymer composite 1 as the aluminum filler content increases.

[0185] As can be seen, the dielectric relaxation and frequency-dependent dielectric constant of the polymer composite can be manipulated by increasing the weight percentage of aluminum flakes. The addition of aluminum flakes significantly increases the dielectric constant, for example, at 60 weight percent, the dielectric constant is significantly increased. Two other notable characteristics include an increase in relaxation (see normalized plot) and a reduction in the loss tangent. For example, at 60 weight percent, the loss tangent is reduced by approximately 30-40% compared to the pure polymer matrix.

[0186] Dielectric properties measurement details and methods

[0187] Experimental Method 1 - Solid-State Material Measurements

[0188] FIG20 shows a solid dielectric evaluation kit used in an embodiment of the present application.

[0189] For dielectric measurements of solid-state materials, the new Thin Layer Dielectric Evaluation Kit (DAK-TL2) from SPEAG (Schmid & Partner Engineering AG, Switzerland) and an R&S VNA were used. This kit, based on the open coaxial probe method for dielectric spectroscopy, enables fast and accurate dielectric measurements of thin layers of solids, semi-solids, gels, and liquids. A DAK3.5-TL2 probe (0.2 GHz to 20 GHz) was used in combination with a ZVL (Rohde & Schwarz, Munich, Germany) to perform measurements within the aforementioned frequency range. The measurement resolution was set to 100 MHz, with a range of 0.2 GHz to 10 GHz. The DAK-TL2 system was calibrated before each measurement using a standard three-point calibration: an open circuit, a short circuit (copper tape), and deionized water as the load. A force of 500 N was applied during the short calibration to ensure good contact between the probe and the copper tape.

[0190] Experimental Method 2 - Liquid Material Measurement - Coaxial Probe Method

[0191] FIG21 shows a liquid dielectric evaluation kit used in an embodiment of the present application.

[0192] For dielectric measurements of liquid materials, an Agilent N9917A FieldFox microwave vector network analyzer (VNA) and a Keysight 85070E dielectric probe kit were used. The instrument's measurement frequency range was 30 kHz to 18 kHz, with 1001 data points. The VNA's RF output authority level was set to 0 dBm. A three-point calibration method, consisting of open circuit (in air), short circuit (calibration module), and 25°C distilled water measurements, was used in accordance with the manufacturer's guidelines. Multiple probes were used to measure each unknown sample, and measurements were performed after repeated calibrations to confirm that the same dielectric constant spectrum was obtained. All measurements were performed at 25°C under an inert nitrogen atmosphere (unless otherwise stated). Liquid samples were stored in 10 mL standard laboratory glass vials with Teflon-lined caps. The probes were immersed in the ionic liquid samples at a depth of approximately 20 mm from the liquid surface. The relative complex dielectric constants of the compounds, including both real and imaginary components, were measured accordingly.

[0193] The above method has been verified by the National Physical Laboratory of the United Kingdom, and the data obtained are accurate and reliable.

[0194] Therefore, the present application provides a new, effective and widely applicable method that can use new processing techniques and non-toxic, low-cost materials to control the dielectric properties (dielectric constant, relaxation and loss) of composite materials, such as significantly increasing the dielectric constant to a desired level while reducing the loss tangent, or introducing dielectric relaxation into the composite material to achieve a frequency-dependent dielectric constant.

[0195] Although many of the numerical values ​​and numerical ranges mentioned in this application are not described with the word "about", it should be understood that these numerical values ​​and numerical ranges, like the numerical values ​​and numerical ranges described with the word "about", can vary within the range of ±5% without departing from the spirit and scope of this application.

[0196] Unless expressly provided to the contrary, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. Although some methods and materials are described in detail herein, methods and materials similar or equivalent to those described herein may also be used to implement this application even if not specifically mentioned herein. For example, the compositions of the various specific dielectric composite materials described herein are not an exhaustive list of the various chemical compositions that can be used to construct the dielectric composite materials provided herein. In addition, the features of one or more of the dielectric composite materials shown can be combined with the features of one or more other dielectric composite materials shown to produce many different combinations, which are within the scope of this application. All publications, patent applications, patents and other references mentioned herein are incorporated herein by reference in their entirety. In the event of a conflict, the definitions in this application shall prevail. In addition, these materials, methods and examples are illustrative only and should not be construed as limiting the scope of protection claimed in this application.

[0197] Although this specification contains many details of specific embodiments, these details should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as detailed descriptions of features that may be features of particular embodiments of particular inventions. Certain features described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment, and various features described in the context of a single embodiment may also be implemented in multiple embodiments, either separately or in any suitable subcombination.

[0198] The acronyms and abbreviations used in this document are listed in the following table:

Claims

1. A non-spherical particle having a first dimension, a second dimension and a third dimension, wherein the first dimension is between 0.01-1 μm, the ratio of the first dimension to the second dimension is between 1 / 10-1 / 1200, and the third dimension is between the first dimension and the second dimension, wherein the non-spherical particle comprises one or more elements selected from titanium (Ti), magnesium (Mg), aluminum (Al), nickel (Ni), silver (Ag), copper (Cu), indium (In), tin (Sn), silicon (Si), boron (B), gallium (Ga), zinc (Zn), iron (Fe), germanium (Ge), bismuth (Bi), gold (Au) and manganese (Mn), and the surface of the non-spherical particle is coated with a surfactant, and the surfactant is one or more selected from fatty acids, organosilicon compounds and combinations thereof. 2 . The non-spherical particles according to claim 1 , wherein the first dimension is between 0.05-0.5 μm, the second dimension is between 5-15 μm, and the third dimension is between 5-15 μm.

3. The non-spherical particles according to claim 1 or 2, wherein the ratio of the first dimension to the second dimension is between 1 / 20 and 1 / 1000. The non-spherical particle according to claim 1 , wherein the non-spherical particle comprises aluminum (Al). 5 . The non-spherical particle according to claim 4 , wherein the non-spherical particle is composed of one or more selected from aluminum (Al), a composite of aluminum, and an aluminum alloy.

6. The non-spherical particles according to claim 5, wherein the aluminum alloy comprises one or more selected from aluminum-gallium (AlGa) alloy, aluminum-magnesium (AlMg) alloy, zinc-aluminum (ZnAl) alloy, copper-aluminum (CuAl) alloy, and aluminum-manganese (AlMn) alloy. 7 . The non-spherical particles according to claim 1 , wherein the non-spherical particles are one or more selected from the group consisting of flake-like particles, rod-like particles, needle-like particles, and dendritic particles.

8. The non-spherical particle according to claim 1, wherein the fatty acid is a hydrophilic carboxylic acid having a saturated or unsaturated hydrophobic aliphatic carbon chain of 18 to 22 carbon atoms.

9. The non-spherical particle according to claim 1, wherein the fatty acid is selected from the group consisting of stearic acid, behenic acid, and combinations thereof.

10. The non-spherical particles according to claim 1, wherein the organosilicon compound has a saturated or unsaturated hydrocarbon chain of more than 18 carbon atoms. The non-spherical particle according to claim 1 , wherein the surface of the non-spherical particle is further coated with a silica shell layer. 12 . The non-spherical particle according to claim 11 , wherein the non-spherical particle comprises aluminum, and a molar ratio of silica to aluminum is 0.4:10 to 5:

10.

13. A method for preparing non-spherical particles according to any one of claims 1 to 12, the method comprising the step of grinding a raw material powder and a surfactant together for 1 to 20 hours to obtain non-spherical particles, wherein the raw material powder contains one or more elements selected from titanium (Ti), magnesium (Mg), aluminum (Al), nickel (Ni), silver (Ag), copper (Cu), indium (In), tin (Sn), silicon (Si), boron (B), gallium (Ga), zinc (Zn), iron (Fe), germanium (Ge), bismuth (Bi), gold (Au) and manganese (Mn), and the surfactant is one or more selected from fatty acids, organosilicon compounds and combinations thereof.

14. The method according to claim 13, wherein the method comprises the step of grinding the raw material powder and the surfactant together in a ball mill for 2-10 hours.

15. The method according to claim 13, wherein the raw material powder comprises one or more of aluminum powder, aluminum composite powder, and aluminum alloy powder. The method of claim 13 , wherein the raw material powder comprises aluminum powder.

17. The method of claim 13, wherein the fatty acid is a hydrophilic carboxylic acid having a saturated or unsaturated hydrophobic aliphatic carbon chain of 18 to 22 carbon atoms.

18. The method of claim 13, wherein the fatty acid is selected from the group consisting of stearic acid, behenic acid, and combinations thereof.

19. The method of claim 13, wherein the organosilicon compound has a saturated or unsaturated hydrocarbon chain of greater than 18 carbon atoms.

20. The method according to any one of claims 13 to 19, wherein the grinding is performed in the presence of a solvent selected from one or more of toluene, mineral oil, hexane, ethanol, acetone, chloroform, dioxane, diethyl ether, ethyl acetate, and combinations thereof.

21. The method according to claim 13, further comprising the step of forming a silica shell layer on the surface of the non-spherical particles.

22. The method according to claim 21, wherein the precursor used to form the silica shell layer is one or more selected from tetraethyl orthosilicate, tetrapropyl orthosilicate, tetraisopropyl orthosilicate, tetrabutyl orthosilicate, tetraisobutyl orthosilicate, tetra-tert-butyl orthosilicate, tetra(methoxyethoxy)silane, sodium silicate (water glass), colloidal silica, and fumed silica.

23. The method of claim 21, wherein the non-spherical particles comprise aluminum, and the molar ratio of silica to aluminum is 0.4:10 to 5:

10.

24. A dielectric composite material comprising the non-spherical particles according to any one of claims 1 to 12 or comprising the non-spherical particles obtained by the method according to any one of claims 13 to 23.

25. The dielectric composite material according to claim 24, wherein the composite material is in a solid state, a semi-solid state, a liquid state, or a liquid-solid mixed state.

26. The dielectric composite material of claim 24, wherein the non-spherical particles are dispersed in a polymer matrix.

27. The dielectric composite material of claim 26, wherein the polymer is one or more selected from polyethylene glycol, polyvinyl chloride, polystyrene, polyisoprene, polyethylene oxide, polypropylene oxide, polytetrafluoroethylene, polyvinylidene fluoride, poly(vinylidene fluoride-co-trifluoroethylene), polyethylene, polypropylene, polyester, polyurethane, polyamide, polyimide, polyetheretherketone, and copolymers thereof.

28. The dielectric composite of claim 24, wherein the non-spherical particles are present in the dielectric composite in an amount less than 80 weight percent based on the total weight of the dielectric composite.

29. The dielectric composite material of claim 24, wherein the non-spherical particles are present in the dielectric composite material in an amount of 5-60 wt% based on the total weight of the dielectric composite material.

30. The dielectric composite of claim 24, wherein the dielectric composite further comprises silica particles.

31. A method for regulating the dielectric properties of a composite material, the method comprising adding non-spherical particles according to any one of claims 1-12 or adding non-spherical particles prepared by the method according to any one of claims 13-23 to a composite material matrix, wherein the dielectric property is selected from one or more of dielectric constant, dielectric loss and dielectric relaxation.

32. The method of claim 31, wherein the method comprises regulating the dielectric properties by adjusting the content of non-spherical particles in the composite material.

33. The method according to claim 31, wherein the method comprises regulating the dielectric properties by adjusting the content of aluminum in the non-spherical particles.

34. The method of claim 31, wherein the method comprises regulating the dielectric properties by adjusting the content and / or type of fatty acid, organosilicon compound, or a combination thereof on the surface of the non-spherical particles.

35. The method of claim 31, wherein the method comprises tuning the dielectric properties by adjusting the thickness of the silica shell of the non-spherical particles, wherein the thickness of the silica shell is adjusted by the molar ratio between the silica shell precursor compound and the non-spherical particle bulk element.

36. Use of the non-spherical particles according to any one of claims 1 to 12, or the non-spherical particles obtained by the method according to any one of claims 13 to 23, or the dielectric composite material according to any one of claims 24 to 30 in preparing a dielectric component.

37. The use according to claim 36, wherein the dielectric component is one or more selected from the group consisting of: an antenna, a radome, a polymer-ceramic composite dielectric component, a capacitor, a printed circuit board, a sensor, an actuator, a resonator, and a waveguide filter.

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