Non-thermal far-infrared radiation high-emissivity ceramic composite

Abstract

To provide a method for manufacturing a ceramic composite capable of being used for various purposes, including incorporation into a therapeutic apparatus for treating a human or animal body with non-thermal far-infrared (FIR) radiation, and to provide a composition.SOLUTION: In a ceramic composite, at least one phase transition is caused so that the ceramic composite includes at least one far-infrared luminescent center in at least one octahedral complex formed by a transition metal ion surrounded by six oxygen anions, or at least one tetrahedral complex formed by a transition metal ion surrounded by four oxygen anions, wherein the anions generate an electrostatic crystalline field around the complex. As a result, the ceramic composite emits non-thermal far-infrared radiation having a wavelength spectrum of 3 to 16 μm, wherein a measurable total radiation over the wavelength range of 8 to 14 μm is approximated as a blackbody radiation at a temperature of at least 1°C higher than the actual object temperature of the ceramic composite, and exhibits an effective emissivity greater than 1.0.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a ceramic composite that can be used for a variety of purposes, including incorporation into a treatment device for treating the human or animal body with non-thermal far infrared (FIR) radiation. More specifically, while all FIR-related prior art only emits broadband blackbody thermal radiation, the ceramic composite can emit not only the usual blackbody thermal radiation, but also the non-thermal FIR photon radiation of the present invention in the 3-16 μm wavelength spectrum. As a result, the entire measurable radiation in the 8-14 μm wavelength range from the ceramic composite has an approximate blackbody temperature at least 1°C higher than the actual temperature of the ceramic composite and exhibits an effective emissivity greater than 1.0, but cannot be exceeded since emissivity 1.0 is the theoretical limit assigned to an ideal blackbody. This is the result of adding the non-thermal FIR photon radiation in the 3-16 μm band to the blackbody thermal radiation in the continuous 4-1,000 μm band. [Background technology]

[0002] Blackbody radiation is the thermal electromagnetic radiation emitted by a black body in thermodynamic equilibrium with its environment. It has a specific continuous spectrum of wavelengths that depends only on the object's temperature. The emitted radiation is rigorously described by Planck's law, and due to its temperature dependence, Planck radiation is called thermal radiation. In the quantum description of Planck's law, radiation is perceived as a gas of massless, uncharged bosonic particles, or photons. Photons are considered as carriers of electromagnetic interactions between charged elementary particles.

[0003] The thermal radiation that is spontaneously and continuously emitted by many common objects can be approximated as blackbody radiation. A blackbody at room temperature (25°C, or 298°K) radiates primarily in the infrared spectrum, spanning the 4-1,000 μm spectrum, with a peak at a wavelength of 9.4 μm, and 90% of the total energy deposited in the 6-25 μm wavelength range.

[0004] This leads to a false belief that the prior art has stuck to: they mistakenly used blackbody thermal radiation in this 6-25 μm wavelength spectrum, expecting the effects to come only from non-thermal FIR photon radiation in the 3-16 μm wavelength range.

[0005] For example, biochemical reaction rates can be increased to different degrees by blackbody thermal radiation or by specific FIR photon radiation with wavelengths between 3 and 16 μm. The rate of a chemical reaction is described by the Arrhenius equation: k=A exp(-E A / RT) where k = rate constant, A = preexponential coefficient, E A = activation energy required (or called "activation barrier"), R = gas constant, T = temperature (°K).

[0006] Absorption of blackbody thermal radiation increases the object temperature. As temperature (T) increases, so does the reaction rate (k). A rough estimate for many reactions occurring near room temperature is that the reaction rate doubles for every 10°C (or 10°K) increase in temperature. In a typical FIR hyperthermia treatment using thermal radiation from prior art FIR emitting materials, the skin temperature increases by about 3-5°C, but the reaction rate increases by only about 30%.

[0007] In contrast, FIR photons with wavelengths between 3 and 16 μm are absorbed by molecules in the object and induce molecular vibrations, which are due to the activation barrier (E A ) by about 8-40KJ, and the formula is: E λ (KJ) = 120KJ / λ(μm). Accordingly, the reaction rate is exponential, exp(E λ / RT) could result in a 5,000-10,000% improvement.

[0008] This surprising effect is precisely the driving force behind the present invention, which proposes the development of a ceramic composite capable of emitting not only conventional blackbody thermal radiation as described in the prior art, but also an unprecedented additional non-thermal FIR photon radiation in the 3-16 μm wavelength spectrum.

[0009] Generally, prior art incorrectly uses blackbody thermal radiation, which is evidenced by the fact that all prior art only searches for FIR materials with emissivity ε as close as possible to the theoretical limit (ε=1.0).

[0010] All physical matter, whether solid, liquid or gaseous, can release energy through the process of electromagnetic radiation due to the vibrational and rotational motion of molecules and atoms. Planck radiation is the maximum amount of radiation that any object in thermal equilibrium can emit from its surface, regardless of its chemical composition or surface structure.

[0011] The emissivity of a material's surface is its efficiency at emitting energy as thermal radiation. Quantitatively, emissivity (ε) is the ratio of the radiant energy emitted by a surface to that emitted by a black body at the same temperature, and is given by the Stefan-Boltzmann law. This ratio varies between 0 and 1 (0<ε<1). All real objects have emissivities less than 1.0 and emit radiation at correspondingly lower rates. For example, everyday objects such as cloth, glass, charcoal, concrete, porcelain, rubber, and sand all have emissivities between 0.80 and 0.98.

[0012] Since FIR radiation became a promising alternative therapy, numerous inventions have been made towards the development of highly effective FIR-emitting materials with the desired emissivity greater than 0.9 (i.e., 0.9<ε<1.0) in mind, but an emissivity of 1.0 is widely recognized as a hypothetical limit that cannot be exceeded.

[0013] Raw metal oxides used in the prior art to manufacture FIR composites typically have individual emissivities between 0.5 and 0.9, depending on the degree of oxidation and surface treatment. The most commonly used FIR emitting oxides include oxides of aluminum, silicon, zirconium, titanium, magnesium, chromium, iron, cobalt, copper, calcium, sodium, etc. All materials are processed into specific shapes in the hope of improving their FIR emissivity by sintering.

[0014] As mentioned above, a key aspect of the design of conventional FIR radiating composites was to achieve an emissivity as close to 1.0 as possible. Nevertheless, all conventional FIR composites treated all of the constituent oxides in an unpurposeful and indiscriminate manner, resulting in emissivities of only around 0.85-0.95 (see, for example, U.S. Patent Nos. 8,285,391, 9,308,388, and 9,962,441, each of which is incorporated by reference in its entirety). None of the conventional techniques targeted emissivities above 1.0, which was considered unattainable since it was a theoretical limit assigned only to an ideal black body.

[0015] The present inventors have previously shared a similar view, which was reflected by the creation of FIR-emitting ceramic composites that require heating when higher radiation is required (e.g., U.S. Patent No. 10,610,699; U.S. Patent Application No. 20210228903, both of which are incorporated by reference in their entirety). However, the present inventors have subsequently studied the properties of transition metal oxides (TMOs) and discovered that by tuning the band gap and lattice constant of the final crystal structure, high emissivity can be obtained in the 3-16 μm wavelength spectrum (e.g., U.S. Patent Application No. 17 / 473,799, both of which are incorporated by reference in their entirety). The present inventors have further pursued this knowledge and, as described herein, have realized certain ceramic composites that can more efficiently and reliably emit FIR photons in the 3-16 μm wavelength range.

[0016] The ceramic composites of the present invention include solid solutions. A solid solution is a homogeneous mixture of two or more crystalline solids sharing a common crystal lattice. A solvent is an element or compound present in the greatest amount (>50 wt%), whereas a solute refers to an element or compound present in a minor concentration (<50 wt%). A solute can be incorporated into the solvent crystal lattice either substitutionally, by replacing the solvent particles within the lattice, or interstitially, by fitting into the spaces between the solvent particles. Both of these types of solid solutions affect the properties of the material by distorting the crystal lattice and disrupting the physical and electrical homogeneity of the solvent material.

[0017] Furthermore, the Hume-Rothery law defines the conditions under which elements in a solute can dissolve in a solvent to form a solid solution: if the solute and solvent have similar atomic radii (difference of 15% or less), electronegativity, valence, and crystal structure, then according to the law, the solute (or impurity atoms) can replace the atoms of the solvent.

[0018] In the present invention, the solid solution contains aluminum oxide (Al 2 O 3 ) because aluminum oxide is an excellent source for constructing the necessary octahedral crystal structure within the host lattice to accommodate the "persistent FIR photon emission mechanism" proposed in this invention. Essentially, silicon oxide (SiO 2 ) provides a more stable aluminosilicate oxoanion (AlSiO 4 - ) substrate construction and therefore a worthwhile option.

[0019] According to the Hume-Rothery law, iron (Fe) and chromium (Cr) are the best candidates as solutes to substitute for aluminum (Al) in the host lattice. The oxides of these elements (Al 2 O 3 , Cr 2 O 3 , Fe 2 O 3 ) all have similar atomic valences and the same octahedral crystal structure. All elements have the same electronegativity (III): Al 3+ , Cr 3+ , Fe 3+ In addition, Cr 3+ Ionic radius of (7.55Å) and low spin Fe 3+ The ionic radius of Al (6.9 Å) is 3+ The difference between the radius of the nucleus and that of the nucleus (6.8 Å) is within 15%.

[0020] Among the aforementioned features, the use of transition metals (TM) in octahedral crystal structures plays a key role in the proposed persistent FIR photon emission mechanism. Both elements iron and chromium belong to the transition metal elements of groups 3 to 12 of the periodic table. Precisely, the TM octahedral structure represents a key building block of the ceramic composite of the present invention.

[0021] Transition Metal Oxides (TMOs) are perhaps one of the most interesting classes of solids, exhibiting a wide variety of structures and properties. The nature of the metal-oxygen (MO) bonds in TMOs ranges from mostly ionic to highly covalent or metallic. The unusual properties of TMOs are apparently due to the unique nature of the outer d electrons in the five degenerate orbitals.

[0022] Based on the molecular orbital (MO) theory of transition metal complexes, the octahedral complex [ML 6 The nature of the transition metal-ligand (ML) bond is clarified by analyzing the molecular orbitals of a 3d metal (M) coordinated to six identical ligands (L) in a 3d-metal complex (M) with six identical ligands (L). The interaction of the metal d-orbitals with the ligand orbitals results in the formation of bonding, nonbonding, and antibonding complex molecular orbitals. The energy levels of the ligand orbitals are usually lower than those of the metal orbitals. The bonding orbitals have more ligand character, whereas the nonbonding and antibonding orbitals have more metallic character.

[0023] The concepts of MO theory are valuable in understanding the reactivity of coordination compounds. One of the fundamental ways in which MO concepts are applied to coordination chemistry is Ligand Field Theory (LFT). LFT focuses on the effect of donor (ligand) atoms on the energy of d orbitals in metal complexes. LFT can be thought of as an extension of crystal field theory so that all levels of covalent interactions can be incorporated into the model. The treatment of bonds in LFT is generally done using MO theory.

[0024] Crystal Field Theory (CFT) is a bonded model that describes the electronic structure of transition metal (TM) complexes. CFT focuses on the interaction between the pentavalent (n-1)d orbitals and the "field" of negative charges (electrons) from the ligands arranged around the TM ion. CFT was developed to explain the interesting spectroscopic properties of TM complexes.

[0025] Assume that the TM complex has an octahedral coordination sphere, with all six ligands aligned along the x, y, and z axes. There are two d orbitals that interact very strongly with these ligands: the d orbitals that lie directly on the x and y axes. x 2 -y 2 and d located directly on the z-axis z 2 These two orbitals have relatively high energy due to the bonding interactions with the donor (ligand) orbitals. These orbitals are called "e g " orbital set. "e g The term "symmetry" comes from the mathematics of symmetry.

[0026] On the other hand, the other three d orbitals, d xy , d xz , d yz All of the orbitals are between the bond axes of the donor ligands and do not collide directly with the donor ligands. These orbitals do not have a strong interaction with the donor electrons. These orbitals are called "t 2g " Sometimes called an orbital set.

[0027] When six negative charges (ligands) are arranged octahedrally around the TM ion, the five d orbitals are divided into two sets of different energies (e g and 2g ) This is called crystal field splitting. In crystal field splitting, the total energy of the d orbital does not change, but the energy of the electron does.

[0028] In a crystalline environment, the five-fold degeneracy of the d orbitals is partially lifted by the electrostatic crystal field and hybridization with the ligand ions. According to the CFT model, factors that influence the orbital energies include the nearest oxygen neighbors, electrostatic potentials from other parts of the crystal, kinetic energy due to hybridization of the metal orbitals with the nearest ligands, radial relaxation of the 3d orbitals, Coulomb and exchange contributions within the 3d shell, and excitations from other orbitals (screening effects).

[0029] e g and 2g The orbital degeneracy of the orbital set can be further lifted by coupling with the lattice, known as the Jahn-Teller effect, which occurs frequently, for example, when manipulating an octahedral crystal structure group to construct a tetragonal unit cell, resulting in tetragonal distortion of the octahedral complex.

[0030] Typically, unit cells within a polycrystal are not unique. Because the ceramic composites of the present invention may contain randomly oriented crystalline domains, the unit cells can be processed into any of seven crystal systems, including triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, and cubic, depending strongly on processing parameters.

[0031] The Jahn-Teller effect is observed in TM ions in electronically degenerate states. In electronically degenerate states, the orbitals are said to be asymmetrically occupied and therefore gain more energy. Thus, the system undergoes a distortion and tries to remove the excess energy by lowering the overall symmetry of the molecule. This is known as the Jahn-Teller distortion effect.

[0032] In other words, orbital degeneracy can be removed by either lengthening bonds along the z-axis ("Z-out" distortion) or shortening bonds along the z-axis ("Z-in" distortion). In this configuration, octahedrally symmetric molecules can be distorted to various degrees, from tetragonal geometry (a=b≠c, α=β=γ=90°) to triclinic geometry (a≠b≠c, α≠β≠γ). Throughout this patent application, the tetragonal system is used as an example due to its simplicity in CFT modeling. This case can be extended to other crystal systems.

[0033] A simple classification of Jahn-Teller (JT) distortion effects is as follows:

[0034] Z-out JT distortion: The bonds along the z axis become longer, so the z factor (d z 2 , d xz , d yz ) lowers the energy of the d orbitals. This is the most favorable distortion and occurs in most cases, but especially e g This occurs when degeneracy occurs at the level.

[0035] Z-in JT distortion: The bond along the z axis is shortened, so the energy of the d orbitals with z factors increases. For example, the octahedral d 1 This type of distortion is observed when the only electron in the xy orbit, t 2g The other two orbitals in the group d xz and d yz has less energy than

[0036] Static JT distortion: Some molecules exhibit a tetragonal shape under all conditions, from low to relatively high temperatures. This is called e g It is observed when orbits become degenerate, and therefore the distortion is strong and persistent.

[0037] Dynamic JT distortion: In some molecules, the random motion of bonds causes no visible distortion or distortion that is so weak that it can be ignored. However, by freezing the molecule at a lower temperature, distortion can be seen.

[0038] As highlighted above, the principles of the present invention include solid solutions, TM coordination complexes, octahedral crystal structures, MO theory, LFT, CFT, crystal field splitting, and JT distortion effects.

[0039] With an understanding of the characterizing science, as disclosed below, the octahedral coordination complex [CrO 6 ] 3+ We can now begin to consider the construction of FIR emission centers using the above.

[0040] The emission of photons occurs when the matrix is ​​capable of emitting light and contains luminescent centers. Any luminescent material is characterized by its host lattice and the specific luminescent centers. The emission of luminescent light (visible, near-infrared, or far-infrared) occurs as a result of a radiative electronic transition in which an electron jumps from a higher energy state to a lower energy state, and the energy difference is released as a photon. It is clear that the electron must first be excited by some means to a higher energy state, and then the stored energy from the excited state is released as a photon, allowing the system to spontaneously return to the ground state.

[0041] The representative component of the FIR luminescence center proposed in this invention is [CrO 6 ] 3+ which consists of six oxygen anions (O - ) surrounded by chromium III ions (Cr 3+ ) is composed of Cr 3+ The ion uses six orbitals of the 4s, 4p, and 4d levels of the chromium atom to accept a lone pair of electrons from the oxygen molecule and bond with oxygen, forming [CrO 6 ] 3+ Form.

[0042] [CrO 6 ] 3+Octahedral Cr 3+ For ions, 4s 1 One from 3d 5 This leaves only three electrons in the 3d orbital, so the 3d 3 The 3d level electrons of the Cr atom do not participate in bonding. In this case, the ligands are oriented on the orthogonal coordinate axes, and the transition metal still occupies the 3d orbitals d xy , d xz , d xz However, these do not interact with the ligands and are considered "non-bonding" orbitals.

[0043] The FIR emission center of the present invention is a 3d 3 Cr with electron configuration 3+ Because they are based on ions, the unit cells of ceramic composites must be purposefully sintered into a crystalline shape that creates a slight "JT distortion in Z-in." After sintering, t 2g The degeneracy of the orbitals of the group is removed. d xy The other two orbitals are d xz and d yz The energy is lower than that of Cr. 3+ The electron pair of the ion is d xy orbitals and the lone electron is d xz Orbitals and d yz Occupy one of the orbits.

[0044] By design, Cr 3+ The ions are arranged in a weak electrostatic crystal field formed by the surrounding anions (or oxoanions) and cations. Based on the CFT model, [d xy ] orbital and [d xz and d yz ] orbital crystal field splitting energy δ 2 is approximately 100-315 meV, which corresponds to a wavelength spectrum ranging from 4 to 12 μm, and is expressed by the formula: E λ (KJ) = 120KJ / λ(μm).

[0045] The CFT model measures the energy of electronic excitations as a function of lattice distortion. According to the transition (selection) rules, the transition requires a quantum overlap of lattice zero-point vibrations. Similarly, the Franck-Condon principle states that during an electronic transition, the greater the overlap between two vibrational wave functions, the easier it is to change from one vibrational energy level to another. The overlap between two vibrational wave functions is called the Franck-Condon overlap (or Franck-Condon factor).

[0046] The Franck-Condon principle helps in the analysis of vibrational transitions and describes the intensity distribution of vibrational bands. It plays an important role in understanding the nature of optical transitions and the optical spectroscopic processes occurring at TM ion sites. This model provides guidance for designing photoluminescence profiles that may include the 3-16 μm wavelength range defined in this invention, although in practice, vibrational transitions may occur within the theoretical 4-12 μm range.

[0047] Cr in octahedral complexes 3+ Ion t 2g 3d between orbits 3 The electron transition serves as the activation center for FIR emission. The energy stored as electrostatic potential during the crystal field splitting (δ 2 ) is released by thermal stimulation, causing “stimulated FIR photon emission” from the luminescent center.

[0048] In summary, the unique "persistent FIR photon emission mechanism" proposed in this invention is significantly different from the teachings of the prior art and can be explained as follows.

[0049] The solid solution of the present invention is a mixture of at least 10% by weight of aluminum oxide (Al 2 O 3 ) and at least 3% by weight of chromium oxide (Cr 2 O 3 ) and / or iron oxide (Fe 2 O 3) where weight percent indicates the percentage relative to the total weight of the complex. In practice, the chromium oxide and iron oxide may be used together or separately as solutes.

[0050] The combination of at least 10 wt. % aluminum oxide in a solvent with 3 wt. % chromium oxide and / or iron oxide as a solute in the present invention provides sufficient [CrO] as FIR luminescence centers for the resulting ceramic composite to effectively generate and emit non-thermal FIR photon radiation. 6 ] 3+ It represents the threshold (minimum requirement) for constructing an octahedron. For better results, it is desirable to combine more such components.

[0051] The solution is sintered at a temperature ranging from 0.5 to 0.75 of the melting point of the solvent. The length of sintering time depends on the temperature selected, during which the host lattice is constructed with aluminum ions in an octahedral structure, during which the aluminum ions (Al 3+ ) is converted to chromium ions (Cr 3+ ) or iron ions (Fe 3+ ) may be substituted.

[0052] During sintering, the ceramic composite is further deliberately treated to induce slight "JT distortions in Z-in" within its constituent unit cells by manipulating the phase transitions of the constituent oxides in a pre-calculated heating cycle. 2g The degeneracy of the group orbitals is removed, d xy The orbital energy is d xz and d yz It is lower than Cr 3+ ionic 3d 3 In the case of three electrons in the configuration, the electron pair is d xy orbitals and the lone electron is d xz Orbitals and d yz Occupy one of the orbits.

[0053] When such a ceramic composite is subjected to a thermal stimulus, a dynamic JT strain is induced. At one extreme of the thermal stimulus, [CrO 6 ] 3+ The z-axis of the octahedron stretches, causing a temporary Z-out JT distortion. xy Orbit is d xz and d yz This swings to have higher energy than d xy Two electrons in the orbital are excited and have energy δ 2 By emitting two photons corresponding to xz and d yz By design, the wavelength of the photon will be in the range of 3 to 16 μm. After emitting two photons, all three electrons will move to lower energy orbitals d xz and d yz Located in.

[0054] Similarly, at the other pole of the thermal stimulus, [CrO 6 ] 3+ The z-axis of the octahedron is shortened, causing a temporary JT distortion of Z-in. d xy Orbit is d xz and d yz swing to have lower energy than d xz Orbitals and d yz Two of the three electrons in the orbital have energy δ 2 By emitting two photons equivalent to xy must descend to

[0055] If the ceramic composite is manufactured correctly as planned, the process of FIR photon generation and emission will continue and persist indefinitely due to the induced effect of "thermally stimulated dynamic JT distortion."

[0056] However, the above explanation of the persistent FIR photon emission mechanism still lacks one important element that links the electronic excitation at the octahedral sites with the stimulated photon emission, namely, phonons (or lattice vibration waves). Therefore, the mechanism proposed in this invention can be called "persistent phonon-activated FIR photon emission".

[0057] Phonons are the quantum mechanical description of the fundamental vibrational motions in condensed matter, where a lattice of atoms or molecules vibrates uniformly at a single frequency. In classical mechanics, this denotes the normal modes of vibration. Any lattice vibration can be considered as a superposition of these fundamental vibrational modes. For crystals with at least two atoms in the elementary cell, the dispersion relations indicate two types of phonons, specifically the optical and acoustic modes.

[0058] At temperatures above absolute zero (0°K or -273°C), the energy of a lattice is not constant, but fluctuates randomly. These energy fluctuations are caused by random vibrations of the lattice and can be thought of as a gas of phonons. These phonons are sometimes called thermal phonons, since they are generated by the temperature of the lattice.

[0059] The thermodynamic properties of a solid are directly related to its phonon structure. The phonon density of states (DOS) describes the phonon dispersion relations of all possible phonons and determines the heat capacity of a crystal. The heat capacity is dominated by the high frequency part of the distribution (optical modes), while the thermal conductivity is a result of the low frequency region (acoustic modes).

[0060] Thermal phonons can be created and destroyed by random energy fluctuations. In statistical mechanics, this means that the chemical potential that adds phonons is zero. The behavior of thermal phonons is similar to the photon gas created by an electromagnetic cavity. It turns out that the electromagnetic field acts like a collection of harmonic oscillators, giving rise to blackbody radiation. Both phonons and photon gases behave similarly in an electromagnetic cavity and follow Bose-Einstein statistics.

[0061] This similarity is no coincidence. Planck's law describes the characteristic spectral distribution of electromagnetic radiation in thermodynamic equilibrium. For matter or net energy not confined in an electromagnetic cavity (such as an ideal blackbody), thermal radiation can be approximately described by Planck's law. From the point of view of quantum mechanics, in such an electromagnetic cavity, both phonons and photons are identical and interchangeable.

[0062] Planck's law arises as a limit to the Bose-Einstein distribution, which describes the energy distribution of non-interacting bosons in thermodynamic equilibrium. For massless bosons, such as photons and phonons, the chemical potential is zero and the Bose-Einstein distribution simplifies to the Planck distribution.

[0063] Kirchhoff's law of thermal radiation states that in thermodynamic equilibrium, the thermal radiation emitted by an ideal black body has a unique universal spectral radiance as a function of temperature, independent of the chemical properties of the material. The radiative transfer equation also describes how radiation is affected as it passes through a material medium. When a material medium is in thermodynamic equilibrium, the thermal radiation from a black body is always equal to the total amount specified by Planck's law.

[0064] As Planck explained, a black body absorbs all electromagnetic radiation that strikes it and does not reflect it. The reflection and transmission of radiation at interfaces obeys the Stokes-Helmholtz reciprocity principle. According to the reciprocity principle, radiation from the interior of a black body is not reflected by its surfaces and is completely transmitted to its exterior.

[0065] Based on the above principles of quantum mechanics, the following can be considered:

[0066] When incident thermal radiation (photons) is absorbed by a black body, waves of lattice vibrations (phonons) are generated within the object. This can be thought of as the thermal radiation (photons) being converted into lattice vibrations (phonons) at the interface through "photon-phonon coupling" involving the conservation of energy and momentum. Similarly, the emission of Planck radiation (thermal radiation) at the surface of a black body can be seen as the generation and emission of photons by lattice vibrations (phonons) within the object to maintain thermodynamic equilibrium, through the reverse process of "photon-phonon coupling".

[0067] The absorptivity (i.e., the energy transfer from incident photons to phonons in a condensed matter) and the emissivity (the energy transfer from phonons to photons) are separate properties of the molecules of a matter and depend on the distribution of molecular excited states at any given time. However, when a matter is in thermodynamic equilibrium, the emissivity and absorptivity are equal. All electromagnetic radiation (thermal radiation) absorbed by a black body is expected to be completely transmitted to its exterior when it is in thermodynamic equilibrium with its surroundings. Indeed, Kirchhoff demonstrated that the absorptivity and emissivity of a black body in thermodynamic equilibrium are equal.

[0068] The equality of absorptivity and emissivity became a norm of belief followed by the prior art. All prior art adhered to this norm as a guide when designing FIR emitting complexes and wanted to develop FIR materials whose emissivity ε was as close as possible to the theoretical limit (ε=1.0), because an ideal black body would have perfect absorptivity equal to 1.0 (i.e. no reflection), and therefore its emissivity would be similar.

[0069] However, the prior art ignores the fact that Planck's law is only applicable when there is no net flow of energy within a body. When there is a flow of energy within a body, such as the ceramic composites of the present invention, the Einstein coefficients discussed by Albert Einstein must come into play.

[0070] The principle of detailed equilibrium requires that in thermodynamic equilibrium, each elementary process must be balanced by an inverse process. In 1916, Albert Einstein applied this principle at the atomic level to the case where atoms emit and absorb radiation due to transitions between two specific energy levels. Einstein gave deeper insight into the radiative transfer equation and Kirchhoff's laws for this type of radiation.

[0071] Level 1 is Energy E 1 and level 2 has energy E 2 For the upper energy level having E 2 -E 1 =hv

[0072] According to Einstein's model, there are three parameters related to the photon frequency ν generated by the transition between two energy levels (states): 21 (spontaneous release), B 21 (evoked release), B 12 (photon absorption). These parameters are known as Einstein coefficients, and each line in the spectrum has its own set of associated coefficients.

[0073] When the atoms and radiation field are in equilibrium, the radiance is given by Planck's law, and by the principle of detailed equilibrium, the sum of the absorptivity and emissivity must be zero. This means that the emission and absorption coefficients are equal. Thus, for isotropic absorption and emission, the relationship of the Einstein coefficients results in the Kirchhoff's law formula mentioned above. In fact, all FIR-related prior art falls into this setting.

[0074] However, when there is a net flow of energy within the object, as is the case in the present invention with a persistent FIR emission mechanism, the emission and absorption coefficients defined in radiative transfer must be expressed in terms of Einstein coefficients. These coefficients apply to both atoms and molecules.

[0075] To put it simply, in a typical case of the prior art, the temperature T 1 A normal material body at temperature T 2 Imagine that the object is in a thermal radiation field of T 2 >T 1 In the case of a material with an absorptivity α, which is the proportion of incident radiation absorbed by the material, the incident energy is absorbed at a rate of α. On the other hand, the material has a temperature T 1 If a material is in thermodynamic equilibrium at temperature T, that is, T=T 1 =T 2 When α = ε, the thermal radiation from the object equals the incident radiation absorbed by the object. In other words, the absorptivity equals the emissivity, i.e., α = ε, which was pointed out by Kirchhoff and is believed in all prior art.

[0076] Conversely, in other cases representative of the present invention, one must consider the net flow of energy within the ceramic composite produced by the persistent phonon activated FIR photon emission mechanism of the present invention.

[0077] Again, the temperature of the ceramic composite is T 1 and the temperature T 2 Assume that the thermal radiation field is 2 >T 1 The composite absorbs incident thermal radiation (photons) and converts the radiant thermal energy into lattice vibrations (phonons) through "photon-phonon coupling". The lattice vibrations instantly induce dynamic JT distortions in the crystal lattice of the ceramic composite, forming [CrO 6 ] 3+The octahedral sites alternate between the "Z-in" and "Z-out" configurations. This results in the generation of FIR photons with wavelengths between 3 and 16 μm, which are spontaneously emitted. In this case, the non-zero Einstein coefficient for stimulated emission, B 21 ≠ 0 exists.

[0078] On the other hand, at the exact moment when the ceramic composite is in thermodynamic equilibrium with its environment at temperature T, i.e. T=T 1 =T 2 Even in the case of phonon-activated photon emission, the lattice vibrations of the composite persist and phonon-activated photon emission continues. As the ceramic composite continuously emits photons at wavelengths between 3 and 16 μm, energy is lost. Then, to maintain thermodynamic equilibrium, the temperature must increase by absorbing incident radiation. Meanwhile, the additional energy absorbed from the incident radiation induces lattice vibrations, which leads to the emission of FIR photons. This cycle is repeated many times, perpetuating the emission of FIR photons.

[0079] To be precise, the technology developed herein by the inventors is comparable to existing technology of persistent emission, also known as Long-Lasting Phosphors (LLP).

[0080] Applications of LLPs include night vision, temperature sensors, LEDs, lasers, medical diagnostics, and in vivo bioimaging (e.g., tumor marking). In these applications, phosphors are excited by X-rays or UV light (ultraviolet rays), and the excitation energy is stored in the phosphor's distorted octahedral sites. The stored energy is released by heat, light, or other physical stimuli, which triggers the emission of visible or NIR light.

[0081] The LLP consists of two sets of orbitals (e g and 2g Broadband energy Δ of crystal field splitting in octahedral configurations between o (the subscript "o" stands for "octahedral"), where Δ o >2 eV. For example, blue LEDs have a Δ o=16,746cm -1 (corresponding to 2.08 eV) of chromium(III)-doped barium borate (BaB 2 O 4 :Cr 3+ ), which emits blue light (λ = 596 nm).

[0082] Alternatively, the present invention provides a method for detecting an energy δ in the range of 100 to 315 meV. 2 t 2g The small energy difference between the d orbitals of the groups (d xy vs. d xz and d yz ) is used to allow the emission of FIR photons in the wavelength spectrum from 3 to 16 μm. In this method, the energy difference (δ 2 ) is so small that FIR photoemission can be activated simply by natural energy fluctuations associated with lattice vibrations (phonons) of condensed matter at room temperature, and therefore no external excitation energy source is required to trigger the FIR photoemission of the present invention.

[0083] In summary, all FIR related prior art teaches only the convention of blackbody thermal radiation and adheres to the concept of equal absorptivity and emissivity, which was derived specifically for black bodies with no net flow of energy through them.

[0084] Therefore, all prior art assumes that the thermal radiation emitted by any object is always equal to the total amount of thermal radiation absorbed, as dictated by Planck's law. This practice is reflected in the fact that FIR materials developed by prior art always aim for the emissivity of an ideal black body (ε=1.0), but an emissivity of 1.0 is considered a theoretical limit that cannot be exceeded. However, prior art always falls short, remaining stuck with emissivities between 0.85 and 0.95.

[0085] Also, when calculating the effect of FIR radiation in therapeutic applications, all prior art aims to "heat" the body part to be treated. This shows that the FIR radiation generated by the prior art is nothing but thermal radiation. As mentioned above, Planckian radiation has a continuous spectrum of wavelengths ranging from 4 to 1,000 μm at room temperature, and 90% of the total energy is accumulated in the 6 to 25 μm range of the FIR spectrum. Although Planckian thermal radiation originally falls into the 6 to 25 μm spectrum, all prior art misunderstands and improperly handles the FIR characteristics of blackbody thermal radiation. This is because blackbody thermal radiation is generated by the water vapor (H 2 O) and carbon dioxide (CO 2 ), otherwise, when interacting with atoms and molecules in condensed matter such as solids and liquids, it is simply thermal radiation for radiative heat transfer.

[0086] In contrast, the present invention discloses a ceramic composite that can emit not only conventional blackbody thermal radiation but also non-thermal FIR photon radiation through an innovative FIR luminescence mechanism called "persistent phonon activated FIR photon emission". The components of the FIR luminescence center are [CrO 6 ] 3+ And so on.

[0087] The ceramic composite of the present invention comprises a solid solution in which the solvent is at least 10 wt. % aluminum oxide and the solute is at least 3 wt. % chromium oxide or iron oxide, or both. The solution is such that the aluminum oxide forms a host lattice having an octahedral crystal structure, and the aluminum ions (Al 3+ ) is partly chromium ion (Cr 3+ ) or iron ions (Fe 3+ ) and is purposely sintered under conditions such that during sintering, transition metal ion coordination complexes (TM ion octahedra) are formed by back diffusion of the cations. Furthermore, the ceramic composite after sintering has a structure in which [CrO 6 ] 3+ or [FeO 6 ] 3+The octahedral primitive cells are intentionally treated to induce a slight "Z-in JT distortion." In this way, [CrO 6 ] 3+ or [FeO 6 ] 3+ FIR luminescence centers are generated at each site.

[0088] In this procedure, chromium ions (Cr 3+ ) or iron ions (Fe 3+ )t 2g The degeneracy of the group orbitals is removed, so d xy The orbital energy is d xz and d yz It is lower than Cr 3+ ionic 3d 3 In the case of three electrons in the configuration, the electron pair is d xy orbitals and the lone electron is d xz Orbitals and d yz orbitals. [FeO 6 ] 3+ A similar outline is observed for Fe 3+ ionic 3d 5 There are five electrons in the configuration.

[0089] When the ceramic composite absorbs thermal radiation from the surroundings, the incident thermal radiation is converted into phonons (waves of lattice vibrations). On the one hand, the lattice vibrations of the composite generate heat, increasing the object temperature, and thermal radiation is emitted to reach and maintain thermodynamic equilibrium with the surroundings. On the other hand, the lattice vibrations induce dynamic JT distortion of the TM ion octahedra, which oscillate between the "Z-in" and "Z-out" JT distortions. As a result, photons in the wavelength range of 3-16 μm are generated, which is related to the energy difference of the crystal field splitting δ 2 The period of lattice vibration is 10 -13 seconds, and electronic transitions are on the order of 10 -16 It occurs on the order of seconds, so that the emission of FIR photons from the ceramic composite of the present invention is spontaneous and continuous.

[0090] Even after the ceramic composite reaches thermodynamic equilibrium with the surrounding environment, the lattice vibrations continue and phonon-activated photon emission continues, so that the 3-16 μm wavelength FIR photon emission from the ceramic composite of the present invention continues indefinitely.

[0091] As disclosed herein, the main property of the persistent FIR emission mechanism of the present invention is the "phonon-activated dynamic JT distortion". The Jahn-Teller effect is a geometric distortion that reduces the symmetry and energy of nonlinear molecular systems. This distortion is typically observed in octahedral complexes, where the two axial bonds can be shorter or longer than the equatorial bond. However, the effect is also observed in tetrahedral compounds.

[0092] It should be noted here that the present invention is based on the octahedral structure [MO], which leads to the selection of aluminum oxide as part of the solvent and chromium(III) oxide and / or iron(III) oxide as the solute. 6 ] 3+ However, tetrahedral compounds can also be used separately to make ceramic composites similar to those described in this invention, or in combination with octahedral compounds to make more stable host lattices.

[0093] Considering the tetrahedral structure, the solvent may include any mineral consisting of silicon oxide or aluminosilicate, and the solute may be any mineral consisting of a tetrahedral crystal structure [MO 4 ] 2+ The oxides may be titanium oxide, zirconium oxide, cobalt oxide, or iron(II) oxide, which share the same structure. If the solvent is composed of both silicon oxide and aluminum oxide, a more stable layered structure constructed by linking octahedra and tetrahedra may be formed.

[0094] As disclosed herein, the science of "persistent phonon activated FIR photon emission" (or in other words "persistent FIR emission"), in which the ceramic composites of the present invention can emit not only blackbody thermal radiation but also non-thermal FIR photon radiation in the wavelength range of 3 to 16 μm, is not taught in the prior art at all. Summary of the Invention [Problem to be solved by the invention]

[0095] It is therefore one object of the present invention to provide a ceramic composite that emits not only blackbody thermal radiation but also non-thermal FIR photon radiation in the wavelength spectrum ranging from 3 to 16 μm.

[0096] It is another object of the present invention to provide a ceramic composite that emits FIR radiation with an effective emissivity greater than 1.0.

[0097] Another object of the present invention is to provide a ceramic composite for incorporation into a therapeutic device that enhances the kinetics of relevant biochemical reactions within the therapeutic body to produce a positive biological effect.

[0098] It is yet another object of the present invention to provide a simple, easy to use, maintenance-free treatment device that can be flexibly attached to any part of the human or animal body in need of treatment.

[0099] These objectives are achieved by a ceramic composite that simultaneously emits blackbody thermal radiation and stimulated FIR photon radiation in the 3-16 μm wavelength spectrum with an effective emissivity higher than that expected from typical blackbody radiating materials. The ceramic composite comprises a mixture of powders to form a solid solution of at least 10% by weight aluminum oxide in a solvent and at least 3% by weight chromium oxide and / or iron oxide in a solute. The solution is sintered to produce a ceramic composite incorporating a sustained FIR light emission mechanism. The ceramic composite may be secured to a flexible attachment means and placed in proximity to a body site requiring treatment.

[0100] Other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following description. [Means for solving the problem]

[0101] According to the invention, a ceramic composite comprises a solid solution in which the solvent is composed of at least 10 wt. % aluminum oxide and the solute is composed of at least 3 wt. % chromium oxide and / or iron oxide, said solution being sintered into a ceramic article comprising an octahedral crystal structure and characterized by a "persistent phonon activated FIR photon emission" mechanism, capable of simultaneously emitting blackbody-like thermal radiation in the wavelength spectrum of 4-1,000 μm and stimulated FIR photon radiation in the wavelength range of 3-16 μm, resulting in an effective emissivity greater than 1.0. Effect of the Invention

[0102] Ceramic composites can be used for a variety of purposes, including providing an effective means to improve the health of the human or animal body, based on the absorption of FIR photons of 3-16 μm wavelength by molecules within the object to enhance the rate of chemical reactions and, as a result, biological effects. [Brief description of the drawings]

[0103] [Figure 1] FIG. 1 is a perspective view of a first embodiment of the present invention, showing a ceramic composite in the shape of a sphere. [Diagram 2] FIG. 4 is a perspective view of a second embodiment of the present invention, showing a ceramic composite in the shape of a circular plate. [Diagram 3] FIG. 11 is a perspective view of a third embodiment of the present invention showing a ceramic composite in the shape of a rectangular plate. [Figure 4] FIG. 13 is a perspective view of a fourth embodiment of the present invention showing a ceramic composite in the shape of a partial cylinder. [Diagram 5] FIG. 13 is a top perspective view of a fifth embodiment of the present invention showing a plurality of ceramic composites secured to a flexible substrate for attachment to a body part to be treated, each ceramic composite having a concave surface facing the body. [Figure 6] FIG. 6 is a bottom perspective view of the embodiment of FIG. 5, showing a pocket that receives the concave ceramic composite. [Figure 7]FIG. 13 is a perspective view of a seventh embodiment of the present invention showing an array of IR emitters embedded within a substrate and disposed within a mounting means. [Figure 8] FIG. 13 is a perspective view of an eighth embodiment of the present invention showing an array of IR emitters embedded within a substrate and disposed within a mounting means. [Figure 9] FIG. 13 is a perspective view of an eighth embodiment of the present invention showing an array of IR emitters embedded within a substrate and disposed within a mounting means. [Figure 10] FIG. 13 is a perspective view of an eighth embodiment of the present invention showing an array of IR emitters embedded within a substrate and disposed within a mounting means. [Figure 11] FIG. 13 is a perspective view of an eighth embodiment of the present invention showing an array of IR emitters embedded within a substrate and disposed within a mounting means. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0104] The present invention is a ceramic composite that can emit not only natural blackbody thermal radiation in the 4-1,000 μm wavelength spectrum, but also innovative non-thermal FIR photon radiation in a specific 3-16 μm wavelength band. The ceramic composite features an ingenious "sustained phonon-activated FIR photon emission mechanism" that absorbs ambient thermal radiation to persistently induce the emission of FIR photons in the 3-16 μm wavelength range.

[0105] The persistent phonon-activated FIR photon emission mechanism (or "persistent FIR emission" mechanism) includes a number of FIR luminescent centers based on transition metal (TM) ion coordination complexes in octahedral or tetrahedral structures. In this invention, we focus only on octahedral structures for ease of design, high efficiency, and predictability of results. Following the teachings of the invention described below, similar complexes can also be made in tetrahedral structures.

[0106] The components of the FIR luminescence center are [CrO 6 ] 3+ [FeO 6 ] 3+etc., which is chromium III (Cr 3+ ) and iron III (Fe 3+ ) surrounded by six oxygen anions forming an octahedral coordination complex. By design, the TM ion is placed in a weak electrostatic crystal field formed by the anions (or oxoanions) in the host lattice and the surrounding doped cations. In this arrangement, the energy of the crystal field splitting, δ, can be determined by predetermining the type and number of doped cations based on CFT modeling. 2 can be approximately 100-315 meV, which corresponds to a wavelength spectrum of 4-12 μm, with the projected emission profile covering a specific wavelength range of 3-16 μm.

[0107] Thus, the ceramic composite is composed of a solid solution with a solvent amount >50 wt. % and a solute amount <50 wt. %. The solvent is at least 10 wt. % aluminum oxide (Al 2 O 3 ), which helps establish the octahedral crystal structure within the host lattice required for the persistent FIR photon emission mechanism. The remaining weight percent of the solvent is made up of aluminosilicates (Al 2 SiO 5 ) to construct a more stable host lattice containing silicon oxide (SiO 2 ). In addition, the oxoanion (SiO 4 4- , AlSiO 4 - ) provides an effective approach to fine-tune the crystal field splitting.

[0108] In practice, the solvent constitutes 50-80 wt. % of the solution, with approximately 10-40 wt. % Al. 2 O 3 and 10 to 40 wt% SiO 2 As an example, 20% by weight aluminum oxide and 40% by weight silicon oxide can be used to construct a stable host lattice that retains a layered architecture with interlocking octahedra and tetrahedra.

[0109] In this study, to demonstrate this concept, Cr and Fe are used in separate cases to substitute for Al in the host lattice. 3+ or Fe 3+ Al in the octahedral sites of the host lattice during sintering 3+ It is expected to be replaced by ions.

[0110] Typically, the solute may contain two parts. The first part is mainly for constructing the FIR luminescence centers and is at least 3 wt. % chromium oxide (Cr 2 O 3 ) and / or iron oxide (Fe 2 O 3 The amount may range from 3 to 40% by weight, preferably from 10 to 20% by weight.

[0111] The second portion of solutes is for fine tuning the crystal field partitioning and may contain 3-20 wt% oxides of other transition metals such as zirconium (Zr), titanium (Ti), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), niobium (Nb), or oxides of alkali or alkaline earth metals such as lithium (Li), sodium (Na), potassium (K), magnesium (Mg), calcium (Ca). Cations from the transition metals or metallic elements are used to manipulate the electrostatic crystal field by interstitially intercalating into the spaces between the solvent particles in the host lattice during sintering.

[0112] It should be noted here that among the aforementioned transition metals, Zr, Ti, Co, and Ni elements can form the host lattice [SiO 4 ] 4- The advantage of this method is that it can be managed to substitute for Si in the tetrahedral structure. In this case, they can act as additional FIR luminescence centers. Or they can be used alone to produce ceramic composites similar to those disclosed in this invention. It will be clear to one skilled in the art to produce such composites following the teachings of this invention by simply modifying the process parameters associated with the selected materials.

[0113] In one embodiment, the solid solution of the present invention comprises 70% by weight of solvent and 30% by weight of solute. The solvent consists of 45% by weight of silicon oxide and 25% by weight of aluminum oxide. The solute consists of 25% by weight of transition metal oxides with 5% by weight of chromium oxide and 15% by weight of iron oxide for FIR emission, and the remaining 5% by weight of minor transition oxides such as zirconium oxide, titanium oxide, zinc oxide as cation dopants. The second part of the solute consists of up to 5% by weight in total of calcium oxide, potassium oxide, magnesium oxide for doping cations.

[0114] After the appropriate oxides are selected, the mixture of these oxides can be processed into molded or powdered form for practical applications such as therapeutic devices. In this process, all the constituent oxides are mixed with binders and stabilizers, followed by grinding, drying, molding, green processing and sintering. The resulting FIR emission spectrum and its spectral intensity depend on the resulting crystal structure and can be affected by many factors, including the sintering temperature, the length of sintering time, the course of the specific procedure and associated heating / cooling rates.

[0115] The powder mixture of the solid solution system is heated to a temperature in the range of 0.5 to 0.75 of the melting point. Al, which has a melting point of 2,073°C, 2 O 3 For , sintering temperatures are typically around 1,000-1,600 °C. During the solid-state sintering process, the powder does not melt. Instead, atomic diffusion in the solid state occurs, bonding the particles together and reducing the porosity (increasing density) of the object.

[0116] In the simplest system, two solid phases A and B react to produce product C. For example, using both aluminum oxide and silicon oxide as solvents, the host lattice product aluminosilicate (Al 2 SiO 5 ) is generated and can be expressed as follows: Al 2 O 3+SiO 2 →Al 2 SiO 5

[0117] On the other hand, during the sintering process, chromium cations (Cr 3+ ) or iron cation (Fe 3+ ) is an aluminum cation (Al 3+ ) occupying the octahedral sites of [Al 2 SiO 5 :Cr 3+ ] or [Al 2 SiO 5 :Fe 3+ ] can form FIR luminescent centers represented by the formula:

[0118] The reaction mechanism involves the back diffusion of cations (Al 3+ vs. Cr 3+ or Fe 3+ ) in which the cations move in opposite directions and the oxygen ions remain essentially stationary. This is the most likely mechanism by which the cation flux is coupled to maintain electroneutrality.

[0119] If the rate of product formation is controlled by diffusion through the product C layer, the product thickness y is observed to follow a parabolic growth law as follows: y 2 =Kt Here, t is the length of sintering time, and K is the rate constant according to the Arrhenius relationship.

[0120] y=r a +r b When r = 1, the reaction is 100% (complete), where r a and r b are the radii of reactants A and B, respectively. This means that the reaction is diffusion controlled, and in practice the diffusion coefficients of such cations vary widely.

[0121] The reaction rate (K) decreases with temperature according to the Arrhenius relationship. The sintering time required to complete the reaction depends on the particle size of the reactants (r a , r b ) increases with increasing diffusion distance (r a +r b ) increases. Therefore, the most important powder properties are size, size distribution, shape, agglomeration, chemical composition and purity.

[0122] Generally, larger particles (>10 μm) require higher temperatures and longer times for the reaction due to diffusion mechanisms during sintering. There is a continuing trend to prepare fine powders, especially very fine powders with particle sizes between 50 and 100 nm (often called nanoscale powders). However, as sizes drop below 1 μm, there is a strong tendency for particles to interact, leading to the formation of agglomerates, which may require proper control.

[0123] Furthermore, the kinetics of particle growth is also affected by the particle size distribution. When the distribution is large, the pressure difference between the small and large particles becomes very large, so the large particles grow much faster at the expense of the small particles compared to when the distribution is narrow. Therefore, it is desirable to have a narrow powder size distribution, e.g., 50-100 nm for nano powders and 1-10 μm for micron particles. However, the optimal particle size and size distribution for practical applications is 0.1-1 μm.

[0124] Usually, uniformity of mixing is one of the most important parameters. It affects the diffusion distance between reactants and the relative number of contacts between reactant particles, producing a homogeneous product. Incomplete reactions, especially with poorly mixed powders, can produce undesirable phases.

[0125] In general, higher temperatures speed up the sintering mechanism and reduce the time required to achieve the diffusion reaction. Higher temperatures favor volume diffusion over interface diffusion. Since grain growth is often controlled by surface diffusion, whereas densification is controlled by volume or grain boundary diffusion, higher temperatures often favor densification over grain growth. Given that interface diffusion mechanisms dominate over volume diffusion, an optimal sintering temperature must be selected. Furthermore, a heating cycle divided into multiple steps with correlated heating / cooling rates is required to achieve the proper phase transformation of the involved elements into the designed polycrystalline structure.

[0126] Thus, in at least one embodiment of the present invention, a three-step process is used in which a heating rate of 5-10°C / min is used to reach a temperature of 1,200°C and the solution is sintered for at least 2 hours to allow for the necessary phase transformation, followed by controlled cooling to lock in the engineered polycrystalline structure phase.

[0127] One important aspect of the present invention is the use of [CrO 6 ] 3+ [FeO 6 ] 3+ The first step is to create FIR luminescence centers in octahedral complexes such as ZnO, ZnSe, ...

[0128] Despite the above guidelines, solid-state reactions in powder systems depend on several parameters, including the chemical nature of the reactants and products, particle size, particle size distribution, particle shape, relative sizes of reactant particles in the mixture, uniformity of mixing, reaction atmosphere, temperature, heating / cooling rates, and time, etc. Therefore, it is difficult to predict the outcome with simplified theoretical models.

[0129] In practice, a large number of experiments need to be carried out to observe the effects of synthesis parameters on the polycrystalline structure and material properties. Before the synthesis process of the ceramic composite of the present invention is perfected, various experimental samples are tried with different sintering temperatures and heating steps. The manufacturing process is certainly not simple. However, those skilled in ceramic processing should be able to experimentally work out their own synthesis parameters following the teachings set forth herein.

[0130] With carefully selected composition and synthesis parameters, the resulting ceramic composite will produce a mixture of crystalline and amorphous regions. Each crystalline region acts as a dipole [CrO 6 ] 3+ or [FeO 6 ] 3+ Allowing electronic transitions within the octahedral structure and controlled by the persistent phonon-activated FIR photon emission mechanism of the present invention, stimulated FIR photons in the wavelength spectrum from 3 to 16 μm are thus generated.

[0131] The ceramic composite of the present invention, made as disclosed above, has an overall FIR emission, including both blackbody-like thermal emission and stimulated FIR photon emission, that can be approximated as a blackbody emission at a temperature at least 1° K (or 1° C) above the actual body temperature of the ceramic composite, which indicates an effective emissivity greater than 1.0 (ε>1.0).

[0132] Figures 1-3 show three different shaped embodiments of the present invention, in Figure 1 the ceramic composite 11 is shaped as a sphere, in Figure 2 the ceramic composite 11 is shaped as a circular plate, and in Figure 3 the ceramic composite 11 is shaped as a rectangular plate. Although it can also be made in powder form, the bulk form has at least three times higher radiation efficiency than the powder form of the same mass.

[0133] The ceramic composite 11 of the present invention can be formed into a variety of shapes and sizes depending on the particular application. In at least one embodiment, the ceramic composite can be circular in shape, with a diameter of 2-50 mm and a thickness of 1-10 mm. In another embodiment, the ceramic composite can be rectangular with dimensions of 2×3 mm to 40×50 mm with a thickness of 1-10 mm. Rectangular and circular ceramics are generally easier to manufacture than other shapes.

[0134] However, it may be advantageous to form the ceramic composite 11 in a concave shape. It is anticipated that the concave surface may aid in concentrating radiation emitted by the ceramic composite to an area or point away from the surface of the ceramic composite. The concave surface may take a variety of shapes, such as a hemisphere, a bowl shape, or a partial cylinder. Figure 4 shows one embodiment of the present invention, in which the ceramic composite 11 has a partial cylindrical shape.

[0135] FIG. 5 shows a preferred embodiment of the invention for therapeutic applications, in which a plurality of ceramic composites 11 are embedded in a substrate 21 made of silicon or a similar material. The substrate 21 is a generally flat sheet and includes a number of pockets 22, which are curved protrusions sized to accommodate the ceramic composites 11. FIG. 6 shows the back side of the substrate 21, which faces away from the body part to be treated. In this embodiment, all of the ceramic composites 11 have the same dimensions, and therefore all of the pockets 22 have the same dimensions. However, in other embodiments, the pockets 22 may have different sizes or shapes to suit a particular application or arrangement of the various ceramic composites 11.

[0136] Also, the ceramic composite 11 of FIG. 5 has a partial cylindrical shape. The partial cylindrical ceramic composite is positioned with the concave surface facing the body area to be treated. This configuration helps to focus the FIR radiation approximately one inch above the surface of the device. When the device is wrapped closely around the body during use, the radiation is focused approximately one inch deep within the body tissue, greatly enhancing the radiation effect within the body.

[0137] FIG. 7 illustrates another embodiment of the invention in which the substrate 23 is housed in an attachment means. Preferably, the attachment means includes a housing 24 and straps 25 attached to either end of the housing 24. In the embodiment illustrated in FIG. 7, the housing 24 includes a hole 29 formed in one side. The hole 29 is sized and positioned such that the pocket 28 in the substrate 23 protrudes partially outside the housing 24, so that the housing 24 is generally flat on the side facing the user. However, other configurations are within the scope of the invention, such as a housing without a hole. This embodiment can be adapted to fit around the waist of a user, with the pocket 28 targeting FIR radiation generally around the lower back of the user.

[0138] FIG. 8 illustrates another embodiment of the present invention in which a substrate 31 is housed in an attachment means. Preferably, the attachment means includes a housing 32 and straps 30 attached to either end of the housing 32. In the embodiment shown in FIG. 8, the housing 32 includes a hole 36 formed in one side. The hole 36 is sized and positioned such that the pocket 34 in the substrate 31 protrudes partially outside the housing 32, so that the housing 32 is generally flat against the user. However, other configurations are within the scope of the present invention, such as a housing without a hole. This embodiment can be adapted to fit around the shoulder of a user, with the pocket 34 targeting FIR radiation generally around the shoulder of the user.

[0139] FIG. 9 illustrates another embodiment of the present invention, in which a substrate 41 is housed in an attachment means. Preferably, the attachment means includes a housing 42 and straps 40 attached to either end of the housing 42. In the embodiment illustrated in FIG. 9, the housing 42 includes a hole 46 formed in one side. The hole 46 is sized and positioned such that the pocket 44 in the substrate 41 partially protrudes outside the housing 42, so that the housing 42 is generally flat on the side facing the user. However, other configurations, such as a housing without a hole, are within the scope of the present invention. This embodiment can be adapted to fit around a user's knee, with the pocket 44 targeting FIR radiation generally around the user's kneecap.

[0140] FIG. 10 illustrates another embodiment of the invention in which a substrate 51 is housed in an attachment means. Preferably, the attachment means includes a housing 52 and straps 50 attached to either end of the housing 52. In the embodiment illustrated in FIG. 10, the housing 52 includes a hole 56 formed in one side. The hole 56 is sized and positioned such that the pocket 54 of the substrate 21 partially protrudes outside the housing 52, so that the housing 52 is generally flat on the side facing the user. However, other configurations are within the scope of the invention, such as a housing without a hole. This embodiment can be adapted to fit around a user's wrist, with the pocket 54 targeting the FIR radiation generally around the user's wrist.

[0141] FIG. 11 shows another embodiment of the invention, in which the substrate 61 is housed in an attachment means. Preferably, the attachment means includes a separable housing 62 for attachment around a body part of a user. In the embodiment shown in FIG. 11, the housing 62 includes a hole 66 formed in one side. The hole 66 is sized and positioned to allow the pocket 64 of the substrate 21 to partially protrude outside the housing 62, so that the housing 62 is generally flat on the side facing the user, and the housing 62 wraps around a body part of the user, such as the forearm, ankle, shin, etc. However, other configurations are within the scope of the invention, such as a housing without a hole. This embodiment can be adapted to fit around the wrist of a user, with the pocket 64 targeting the FIR radiation generally around the body part of the user.

[0142] The substrates 21, 23, 31, 41, 51, 61 in various embodiments may be made from silicone (polydimethylsiloxane), zinc sulfide, sodium chloride, potassium bromide, or similar materials.

[0143] In the experiment, the ceramic composite was fabricated in the shape of a 12 mm long cylindrical tube cut into one third around a circle with ID (inner diameter) of 10 mm and OD (outer diameter) of 20 mm. The specific spectral radiance of the ceramic composite was measured to cover the wavelength spectrum from 3 to 16 μm. Furthermore, the thermal radiation, which is the stimulated FIR photon radiation in the wavelength range of 8 to 14 μm plus blackbody-like thermal radiation, was measured with a commercial sensor and approximated as blackbody radiation at a temperature about 3 °C higher than the actual temperature of the ceramic composite, showing an effective emissivity of 1.04 (ε = 1.04).

[0144] (Conclusions, Implications, and Scope) According to the present invention, the ceramic composite is characterized by a persistent phonon-activated FIR photon emission mechanism capable of simultaneously emitting blackbody thermal radiation in the wavelength spectrum of 4-1,000 μm and induced FIR photon radiation in the wavelength band of 3-16 μm, resulting in an effective emissivity greater than 1.0. The ceramic composite can be used for a variety of purposes, including providing an effective means for improving the health of the human or animal body based on the enhancement of chemical reaction rates in the body through the absorption of FIR photons in the wavelength range of 3-16 μm, which results in favorable biological effects.

[0145] Having described the present invention, it will be apparent that numerous modifications and variations of the present invention are possible in light of the above teachings. Such variations are not to be regarded as departing from the spirit and scope of the present invention, and all modifications that would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

[0146] (CROSS REFERENCE TO RELATED APPLICATIONS) This application is a continuation-in-part claiming the benefit of Application No. 17 / 473,799, filed September 13, 2021, which is incorporated herein by reference in its entirety. [Explanation of symbols]

[0147] 11: Ceramic composite 21, 23, 31, 41, 51, 61: Substrate 22,28,34,44,54,64:Pocket 24, 32, 42, 52, 62: Containment 25,30,40,50:Strap 28,34,44,54,64:Pocket 29, 36, 46, 56, 66: Hole

Claims

1. 1. A method for making a non-thermal far infrared (FIR) emitting ceramic composite, comprising: a) heating a powder material at a heating rate to reach a sintering temperature; b) sintering said powder material at said sintering temperature for a sintering time; c) cooling the powder material at a cooling rate to form a ceramic composite; Steps a)-c) induce at least one phase transition such that the ceramic composite contains at least one far infrared emissive center in at least one octahedral complex formed by a transition metal ion surrounded by six oxygen anions or at least one tetrahedral complex formed by a transition metal ion surrounded by four oxygen anions; The anion creates an electrostatic crystal field around the complex; As a result, the ceramic composite emits non-thermal far infrared radiation in the wavelength spectrum of 3 to 16 μm; wherein the total measurable radiation over the wavelength range of 8 to 14 μm is approximated as blackbody radiation at a temperature at least 1° C. above the actual body temperature of the ceramic composite and exhibits an effective emissivity greater than 1.

0.

2. 10. The method of claim 1 , The method of claim 1, wherein the material is produced by mixing a solvent containing at least about 10% by weight of a first oxide with a solute containing at least about 3% by weight of a second oxide and between about 3% by weight and about 20% by weight of a third oxide.

3. 10. The method of claim 1 , The method of claim 1, wherein the first oxide comprises one or more of a silicon oxide and an aluminum oxide.

4. 10. The method of claim 1 , The method of claim 1, wherein the second oxide comprises one or more of a chromium oxide and an iron oxide.

5. 10. The method of claim 1 , The third oxide comprises one or more of zirconium oxide, titanium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, niobium oxide, lithium oxide, sodium oxide, potassium oxide, magnesium oxide, and calcium oxide.

6. 10. The method of claim 1 , The method, wherein the heating rate is from about 5 degrees / minute to about 10 degrees / minute.

7. 10. The method of claim 1 , The method according to claim 1, wherein the sintering temperature is about 1,000 to 1,600°C.

8. 10. The method of claim 1 , The method, wherein the sintering temperature is about 50% to about 75% of the melting point of the solvent.

9. 10. The method of claim 1 , The method according to claim 1, wherein the sintering time is at least 2 hours.

10. A ceramic composite composition that emits non-thermal far infrared radiation, comprising: a solvent for the first oxide of about 10% by weight or more; % or more by weight of a second oxide and a solute comprising from about 3% to about 20% by weight of a third oxide.

11. The composition according to claim 10, The composition, wherein the first oxide comprises one or more of silicon oxide and aluminum oxide.

12. The composition according to claim 10, The second oxide comprises one or more of a chromium oxide and an iron oxide.

13. 11. The composition of claim 10, The third oxide comprises one or more of zirconium oxide, titanium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, niobium oxide, lithium oxide, sodium oxide, potassium oxide, magnesium oxide, and calcium oxide.

14. 1. A therapeutic device for treating the human or animal body, comprising: A treatment device comprising: a ceramic module capable of emitting blackbody thermal radiation and stimulated far-infrared photon radiation having an effective emissivity greater than about 1.0; and a flexible means for attaching said module to a body part to be treated.

15. 15. The treatment device of claim 14, The ceramic module emits blackbody thermal radiation at wavelengths of about 4 to about 1,000 μm and stimulated FIR photon radiation at wavelengths of about 3 to about 16 μm.

16. 15. The treatment device of claim 14, The treatment device, wherein the ceramic module comprises three oxides.

17. 17. The treatment device of claim 16, The first oxide comprises one or more of silicon oxide and aluminum oxide.

18. 17. The treatment device of claim 16, The second oxide comprises one or more of a chromium oxide and an iron oxide.

19. 17. The treatment device of claim 16, The third oxide comprises one or more of zirconium oxide, titanium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, niobium oxide, lithium oxide, sodium oxide, potassium oxide, magnesium oxide, and calcium oxide.

20. 15. The treatment device of claim 14, the ceramic module comprises at least one FIR luminescent center in at least one octahedral complex formed by a transition metal ion surrounded by six oxygen anions; The anion creates an electrostatic crystal field around the complex; As a result, the ceramic composite is characterized as having a sustained phonon activated FIR photon emission mechanism.

Images