Water cluster, method for manufacturing a water cluster, and method for using a water cluster

Abstract

To provide a water cluster capable of maintaining an ordered structure even at a high temperature.SOLUTION: The water cluster has a structure in which H ions and / or OH ions are bonded to the surface of an aggregate in which water molecules are bonded by hydrogen bonds. The water cluster satisfies the relation S1≤S2 when S1 is the S-parameter after the positron age of 2 nanoseconds measured at 8°C by a positron annihilation gamma-ray lifetime-momentum correlation measurement (AMOC) and S2 is the S-parameter measured at 10°C.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present invention relates to water clusters, a method for producing water clusters, and a method for using water clusters.

Background Art

[0002] Although research on environmentally friendly solvents such as ionic liquids has been actively conducted, the solvent with the least environmental impact is water, and the use of water is extremely important in many fields including the industrial field.

[0003] It has been proposed that water has two liquid structures: an ordered structure (Figure 1) and a disordered structure (Figure 2) that closely resembles ice (Non-Patent Document 1). Subsequently, research on the observation of the liquid structure of water and computational science has been carried out (Non-Patent Document 2).

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the method for controlling the liquid structure of water has not yet been elucidated, and furthermore, there is a problem that the ordered structure of water clusters changes to a disordered structure under high-temperature conditions. An object of the present invention is to provide a water cluster that can maintain an ordered structure even at high temperatures.

Means for Solving the Problems

[0006] The inventors of the present invention have conducted extensive research to solve the above problems and have found that the above problems can be solved by using water clusters on which H ions and / or OH ions are bound to the surface, and which satisfy the relationship S1 ≤ S2 when the S-parameter measured at 8°C at a positron age of 2 nanoseconds or more by positron annihilation gamma-ray lifetime-momentum correlation (AMOC) is denoted as S1 and the S-parameter measured at 10°C is denoted as S2, thereby completing the present invention.

[0007] In other words, the present invention relates to the following [1] to [7]. [1] A water cluster having a structure in which H ions and / or OH ions are bonded to the surface of an aggregate of water molecules linked by hydrogen bonds, The water containing the water cluster satisfies the relationship S1 ≤ S2, where S1 is the S-parameter measured at 8°C at a positron age of 2 nanoseconds or more by positron annihilation gamma-ray lifetime-momentum correlation (AMOC) and S2 is the S-parameter measured at 10°C. [2] The water cluster according to [1], capable of trapping ions and / or ionic compounds by hydrogen bonding. [3] The water cluster described in [1], wherein the structure of the water cluster is represented by formula (A). [ka] [In equation (A), m, n, and l are integers from 0 to 30, m+n is an integer greater than or equal to 1. m+n+l is an integer between 10 and 30. [ka] This indicates a hydrogen bond. [4] The water cluster described in [2], wherein the structure of the water cluster is represented by formula (B). [ka] [In equation (B), o, p, and r are integers from 0 to 30, q is an integer between 1 and 30. o+p is an integer greater than or equal to 1, o+p+q+r are integers between 10 and 30. [ka] This indicates a hydrogen bond. A method for producing water clusters as described in [5][1] or [3], comprising the following steps (i) to (iii). (i) A selection step to identify the cooling temperature [°C] and the storage time [day] corresponding to the cooling temperature, based on a predetermined correspondence between the S-parameter [-] in water measured by the positron annihilation gamma-ray lifetime-momentum correlation (AMOC) method, the temperature of the water [°C], and the storage time [day] at the water temperature. (ii) A cooling step of cooling water to a temperature below the cooling temperature [°C], (iii) A storage step in which the water is stored at a temperature below the cooling temperature [°C] for a storage period [day] or longer after the cooling step. A method for producing water clusters as described in [6][2] or [4], comprising the following steps (i) to (iv). (i) Based on the predetermined correspondence between the S-parameter [-] measured by the positron annihilation gamma-ray lifetime-momentum correlation (AMOC) method, the water temperature [°C], and the storage time [day] at the water temperature, the cooling temperature [°C] and the storage corresponding to the cooling temperature A specific process that identifies the time [day], (ii) A cooling step of cooling water to a temperature below the cooling temperature [°C], (iii) A storage step in which the water is stored at a temperature below the cooling temperature [°C] for a storage period [day] or longer after the cooling step, (iv) A heating step in which the water is heated to a temperature of 5°C or higher after the storage step. A method of using a water cluster as described in any of [7][1] to [4], Method of using the water cluster for industrial use and / or medical use.

Advantages of the Invention

[0008] According to the present disclosure, a water cluster capable of maintaining an ordered structure even at high temperatures can be provided.

Brief Description of the Drawings

[0009] [Figure 1] It is a diagram showing a symmetrical water cluster structure. [Figure 2] It is a diagram showing an asymmetrical water cluster structure. [Figure 3] It is a diagram showing the pH change with respect to the heating rate of the water cluster of the present embodiment. [Figure 4] It is a diagram showing the pH change at a cooling rate of -0.5 °C / hour showing the formation of the water cluster of the present embodiment. It is measured after sufficiently eliminating the cluster structure at 45 °C. [Figure 5] It is a diagram showing the pH change due to the formation of the water cluster of the present embodiment at 2.5 °C. [Figure 6] It is a diagram showing the time dependence of the existence probability of the singlet state of a geminate radical pair by an electron spin rotating at a speed of 2 nanoseconds and an electron spin rotating at 10 picoseconds, whose rotation direction is unknown. [Figure 7] It is a reaction flow diagram with a conceptual diagram of the singlet state and the triplet state inserted. [Figure 8] It is a block diagram of the apparatus used for the AMOC measurement method. [Figure 9] It is the energy spectrum (total absorption peak) of positron-electron two-photon pair annihilation gamma rays measured by a Ge semiconductor detector. <> [Figure 10] It is a diagram showing the positron age dependence of the positron annihilation gamma ray energy distribution in water obtained by AMOC at 18 °C. [Figure 11]This figure shows the positron age dependence of the positron annihilation gamma-ray energy distribution in water with a conventional cluster structure, obtained by AMOC at 2.5°C. The S-parameters are normalized to the S-parameters for positron ages of -0.1 to 0.2 nanoseconds. [Figure 12] This figure shows the positron age dependence of the positron annihilation gamma-ray energy distribution in water having the cluster structure of the present invention, obtained by AMOC at 0.6℃. The S-parameters are normalized to the S-parameters for positron ages of -0.1 to 0.2 nanoseconds. [Figure 13] This figure shows the measurement results of the S-parameter [-] in water measured by the AMOC method in the examples (conditions 1-3). The S-parameter is normalized to the positron age of -0.1 to 0.2 nanoseconds. The time resolution of the AMOC method is 230 picoseconds in full width at half maximum. [Modes for carrying out the invention]

[0010] The following describes specific embodiments, but each embodiment is presented as an example of the present invention and does not necessarily specify the invention as claimed. Furthermore, not all of the features described in the embodiments are essential for solving the problems of the present invention.

[0011] When a numerical range is expressed as "XX or greater and YY or less" or "XX to YY," unless otherwise specified, it means a numerical range that includes the lower and upper limits. When a numerical range is expressed in steps, the upper and lower limits of each range can be combined in any way.

[0012] [Water cluster] A water cluster according to one embodiment of the present invention has a symmetrical water cluster structure, as shown in Figure 1, that is, an ordered structure very similar to ordinary ice (ice Ih phase). Ordinary water clusters undergo a significant change in their cluster structure above approximately 10°C, and lose their ability to maintain their ordered structure (H Okajima, M Ando, ​​H Hamaguchi. Formation of “Nano-Ice” and Density Maximum Anomaly of Water. Bull. Chem. Soc. Jpn.2018, 91, 991-997). On the other hand, the water cluster of this embodiment can maintain its ordered structure up to approximately 40°C. The water cluster of this embodiment is preferably obtained by the water cluster manufacturing method described later.

[0013] The water cluster of this embodiment is a water cluster having a structure in which H ions and / or OH ions are bonded to the surface of an aggregate of water molecules linked by hydrogen bonds. By bonding H ions and / or OH ions to the surface, the ordered structure can be maintained even at temperatures above 10°C.

[0014] The presence of H ions and / or OH ions bound to the surface of the water cluster in this embodiment can be confirmed by the change in pH readings (when using a Horiba 300-PC unrefilled pH sensor) when the temperature of the water cluster is changed. Figure 3 shows the change in the pH value (hereinafter referred to as pH) of the water containing the water cluster in this embodiment.

[0015] When the temperature was increased at a constant rate of 0.4°C / hour, the pH initially decreased. This is a change that shows the normal temperature dependence of pH, but at 30°C, the pH actually increased. This occurs because, as the temperature rises, molecular mobility increases and some ions are eliminated, causing a decrease in proton conductivity. When the heating rate was increased to 1.8°C / hour above 40°C, the pH decreased significantly. This indicates that H ions bound to the surface of the water clusters were being detached, meaning the detachment rate increased in response to the heating rate. Above 43°C, the pH rose again, indicating that the proton conductivity decreased due to the breakdown of the water cluster structure caused by proton detachment, etc.

[0016] Furthermore, in this embodiment, the water cluster satisfies the relationship S1 ≤ S2, where S1 is the S-parameter measured at 8°C by positron annihilation gamma-ray lifetime-momentum correlation (AMOC) and is defined as the S-parameter measured at 10°C, and S2 is defined as the S-parameter.

[0017] Positron annihilation gamma-ray lifetime-momentum correlation (AMOC) The UM correlation method is a method for measuring the positron age dependence of the momentum of the electron that is annihilated by a positron. Here, it is used to obtain information about the reaction between positronium, which is the bonded state of a positron and an electron, and surrounding free radicals. First, let's explain the mechanism of free radical generation by positrons. Electrons within a molecule form pairs, and two electrons occupy the same orbital. Electrons have spin, and in this state, the spin of this electron pair is in a singlet state.

[0018] The following equations (1) to (5) describe the reaction when a positron is incident on water. Like electrons, the incident positron imparts energy to the molecule along its range, and when this energy is absorbed by the water molecule, the reaction in equation (1) occurs. When the water molecule is ionized as in equation (1), the unpaired electron and the ejected electron (daughter electron) in the resulting positive ion radical (parent ion radical) are singlets and retain their spin memory. Subsequently, various reactions from equation (1) to equation (3) occur in the picosecond time domain, and the unpaired electron in the parent ion radical retains its spin memory, sometimes transforming into a different radical (referred to here as the parent radical). In the case of water, it transforms into a short-lived OH radical (·OH) as in equation (3).

[0019] On the other hand, an incident positron can form positronium in the picosecond range with its daughter electron, as shown in equation (2), and the memory of the electron's spin within the positronium is preserved. The electron within the positronium rotates due to hyperfine coupling with the spin of the positron with which it forms a pair, but its period is about 10 picoseconds, which is faster than the time resolution of the instruments used to measure normal positron annihilation (approximately 200 picoseconds), so it cannot be observed. Meanwhile, the electron within the parent radical also rotates due to hyperfine coupling with the nuclear spin inside the parent radical. This period depends on the hyperfine coupling constant with the nuclear spin, and if the hyperfine coupling constant is large, it becomes nanosecond-range. This change can be tracked with the time resolution of the instruments used in positron annihilation.

[0020] As shown in equation (2), 1 / 4 of positronium is formed as para-positronium, which annihilates in 125 picoseconds. The remaining 3 / 4 is ortho-positronium, which has a lifetime of about 1 to 10 nanoseconds in normal liquids and solids. This long-lived ortho-positronium can react with parent radicals as shown in equations (4) and (5). Positronium consists of one positron and one electron and is a type of free radical. Reactions between a parent radical and a positronium pair containing a daughter electron (geminate radical pair) are radical reactions or electron transfer reactions. Radical reactions (including electron transfer) like equation (4) are possible when the unpaired electrons in the two radicals are in singlet form, according to the Pauli principle. Spin exchange reactions like equation (5) are also possible between the parent radical and positronium, and these do not show spin dependence. Typically, the reaction rate of such reactive species is determined by diffusion, and the sum of the rates of the radical reaction in equation (4) and the spin-exchange reaction including equation (5) is approximately constant. In other words, when an OH radical and ortho-positronium meet, the spin-exchange reaction in equation (5) is always possible, and the radical reaction in equation (4) exhibits spin dependence.

[0021]

number

[0022] Here, o-Ps represents ortho-positronium, p-Ps represents para-positronium, and PsOH represents the bonding state between positronium and the OH radical. In equation 5, (↑) and (↓) represent the spins of the unpaired electrons in the free radical, 1 / 2 and -1 / 2, respectively. At the time of ionization, the electron in the parent radical and the daughter electron in the ortho-positronium are in the singlet state. Subsequently, the spin of the electron in the parent radical rotates with a period of about nanoseconds, and the spin of the electron in the ortho-positronium rotates with a period of about 10 picoseconds. In this state, the direction of electron spin rotation depends on the spin direction of the nucleus or positron of the hyperfinely bonded partner. Therefore, this geminated radical pair oscillates between the singlet and triplet states according to the difference or sum of the rotation speeds of these two electron spins, and since it is impossible to know which state is occurring, a superposition of these two states is observed. As a result, the time dependence of the probability of existence of the singlet state shows a slow rotation caused by the hyperfine coupling of free radicals as a wave with a short period of 10 picoseconds. This is shown in Figures 6 and 7.

[0023] For example, in Figure 6, at 500 and 1500 picoseconds, the probability of singlet existence is 0.5. When ortho-positronium and radicals in a germinated radical pair meet, half undergo a radical reaction, while the other half fail to undergo a radical reaction, resulting only in a spin exchange reaction. Furthermore, at 0 or 1000 picoseconds, the probability of singlet existence oscillates between 0 and 1 with a period of 10 picoseconds. All germinated radical pairs pass through the point where the probability of singlet existence is 1 at 10 picosecond intervals, and as a result, many germinated radical pairs can undergo radical reactions.

[0024] In summary, at 0 and 1000 picoseconds, much of the ortho-positronium that forms the gemminate radical pair undergoes radical reactions, resulting in bonding states and oxidation as shown in equation (4). At 500 and 1500 picoseconds, half proceed to the reaction shown in equation (4), while the other half undergoes only spin exchange reactions and disappears as para-positronium. In other words, the disappearance from para-positronium is maximized at 500 and 1500 picoseconds, which corresponds to half the period of electron spin rotation due to the actual hyperfine bonding of radicals.

[0025] When a positron annihilates in a liquid or solid, the energy equivalent to the mass of the annihilated electron and positron is given by E=mc². 2 It is emitted according to this principle. In this process, in order to conserve energy and momentum, two gamma rays are emitted in opposite directions in almost all cases. The energy is approximately 511 keV, but a shift (Doppler shift) occurs depending on the momentum of the electron and positron just before annihilation. The magnitude of this shift is small in the case of para-positronium and large in the case of ortho-positronium. This shift is actually observed as a change in the broadening of the peak due to the annihilation gamma-ray energy. As mentioned above, if annihilation from para-positronium increases with a certain period, a periodicity will be observed in the broadening of this annihilation gamma-ray energy. It will oscillate with a period twice that of the actual radical spin oscillation.

[0026] In this way, by directly observing short-lived free radicals, such as OH radicals formed in water, whose reactions occur in nanoseconds, we can elucidate the structure of short-lived free radicals, the nanosecond-level interactions and reactions between short-lived free radicals and surrounding molecules, and evaluate their diffusion and molecular mobility around the free radicals.

[0027] In molecules and atoms, two electrons occupy a single orbital. These two electrons are in a singlet state, as shown in Figure 7. The arrows indicate the electron spins, and electrons in the same orbital are in the same environment and therefore rotate at the same frequency. When one electron is ejected during ionization, the pair of electrons that were in a singlet state at that moment are placed in different environments, resulting in them rotating at different periods. This difference in periods causes them to oscillate between triplet and singlet states, as shown in Figures 6 and 7.

[0028] Free radicals contain unpaired electrons, which result in high reactivity. According to Pauli's principle, in reactions between free radicals or electron transfer between them, the reaction will not proceed unless the free radicals are in a singlet state, as they cannot occupy the same orbital. In this measurement method using positrons, positrons incident from a positron source cause ionization of molecules and atoms, capturing the electrons emitted during this process to form positronium. Therefore, positronium possesses unpaired electrons and is a free radical. The ion remaining after electron emission during ionization also contains unpaired electrons, and this ion, or the reactive species formed from it, is a free radical. To react with positronium or undergo electron transfer, it must be in a singlet state. On the other hand, the electron spins of unpaired electrons within a free radical can exchange states through spin exchange reactions. In the diffusion-controlled reaction between a free radical and positronium, only spin exchange reactions occur if the free radical is in a triplet state, while radical reactions and electron transfers are possible if the free radical is in a singlet state.

[0029] Figure 8 shows the apparatus 100 used for the age-momentum correlation (AMOC) method of positron annihilation gamma-ray lifetime-momentum. AMOC is a measurement technique that combines positron annihilation lifetime measurement (PAL) and annihilation gamma-ray Doppler width measurement (DBPA: Doppler broadening of positron annihilation radiation). Positron sources used include those using radioactive isotopes and those using positron beams. In Figure 8, the method for obtaining the start signal for lifetime measurement is (1) the positron source. 22 (1) Some methods, like the early AMOCs that used Na directly, detect 1.27 MeV gamma rays emitted simultaneously with positron emission; (2) others, when using a low-energy positron beam, utilize the pulsed signal of the beamline.

[0030] In Figure 8, the apparatus 100 consists of a container 10 that holds a sample into which positrons are incident, a scintillation detector (SD) 20 that detects gamma rays generated in the container 10 by the reaction between the positrons and the sample, a lifetime measurement system (PAL) 30 connected to the SD 20, an AMOC system 40 which is a two-dimensional multi-wave height analyzer (2D-MCA), a Ge semiconductor gamma-ray detector (SSD) 60 that detects annihilation gamma rays, and a Doppler broadening measurement system (DBPA) 50 connected to the SSD 60. The PAL 30 and SSD 60 are connected to the AMOC system 40.

[0031] As shown in Figure 8, positron e + The positron annihilates with an electron in the sample, producing two annihilation gamma rays. One of these is used as a stop signal for the lifetime measurement system PAL30, while the other annihilation gamma ray is detected by a Ge semiconductor detector (SSD) 60 with high energy resolution to obtain the DBPA. By performing a correlation measurement of the lifetime information and DBPA information using a two-dimensional multi-wave height analyzer (2D-MCA) based on simultaneous counting, an AMOC spectrum is obtained. In other words, the correlation measurement allows for the measurement of energy information of the annihilation gamma ray from the same positron whose lifetime was measured. Recently, it has become possible to record all the signal waveforms from these detectors and perform the same measurements using a computer program.

[0032] The spectrum shown in Figure 9 is the spectrum of gamma rays at approximately 511 keV emitted by the two-photon annihilation of electron-positron pairs, as measured by the Ge semiconductor detector (SSD) 60.

[0033] Gamma rays emitted from radioactive isotopes have uniform energy, and the peak shape of the measured gamma rays indicates the energy resolution of the instrument. However, annihilation gamma rays exhibit an energy broadening due to the Doppler effect, depending on the momentum of the electrons and positrons at the time of annihilation. This difference in Doppler broadening allows for qualitative discussion of, for example, whether there is a large or small amount of annihilation from the para-positronium state. S-parameters are often used for qualitative discussion. S-parameters are defined as the ratio of the area of ​​a given central region to the area of ​​the entire peak. As annihilation from para-positronium increases, the peak becomes sharper, and as a result, the S-parameter increases. In Figure 9, widths W1 and W2 indicate the range for deriving the S-parameter. The S-parameter is obtained as the ratio of the area of ​​the region contained in the central part of the spectrum within width W2 to the area of ​​the entire spectrum contained within width W1.

[0034] The phenomenon where the generated geminated radical pair reacts without diffusing for some reason is called the "cage effect." The water clusters in this embodiment can maintain a symmetrical cluster structure up to about 40°C. Long-range diffusion of radicals is suppressed by cluster formation, and the cage effect appears. In other words, even at rising temperatures, the spin exchange reaction between the OH radical and o-Ps in the water clusters of this embodiment is significantly reduced due to the cage effect caused by cluster formation, as the spin exchange reaction between the parent OH radical and daughter o-Ps, which retain spin memory, is significantly reduced. This increases the yield of p-Ps formation, and the S-parameter does not increase or decrease.

[0035] On the other hand, when the temperature of a normal water cluster is raised to around 10°C, the cluster structure changes and the cluster disappears. As a result, the cage effect disappears, and the S-parameter decreases.

[0036] Figure 10 shows the results of AMOC measurements in water. In Figure 10, S(t) refers to the S-parameter for positron age t, measured by the time difference between the start signal, which indicates the time of positron incidence into the sample, and the stop signal, which detects the annihilation gamma ray indicating positron annihilation using the SD, as shown in Figure 7. A large value of S(t) indicates a narrow annihilation gamma ray energy distribution. The arrows indicate the peak positions.

[0037] In Figure 10, oscillations in S(t) are observed from 2 nanoseconds to 10 nanoseconds in the 18°C ​​measurement. This indicates that oscillations are occurring in the broadening of the energy distribution of the annihilation gamma rays. This time domain corresponds to the annihilation from ortho-positronium, which exhibits the longest lifetime in the positron annihilation process. In water, it generally exhibits a lifetime of approximately 2 nanoseconds. In the 18°C ​​measurement results, for example, the region where S(t) increases around 2.8 nanoseconds indicates that the energy distribution of the annihilation gamma rays is narrowing, indicating a smaller broadening of the energy distribution. This indicates an increase in the component in which ortho-positronium is converted to para-positronium and annihilated, and that the spin exchange reaction between the parent OH radical and daughter o-Ps described above is occurring. In other words, at this time, the germated radical pair, that is, the unpaired electrons in ortho-positronium and some of the unpaired electrons in the free radical (in this case, the OH radical), cannot become a singlet state. Subsequently, around 3.5 nanoseconds, S(t) decreases, indicating a large spread in the energy distribution of the annihilation gamma rays, suggesting that a spin exchange reaction is not occurring. This means that a radical reaction is taking place between the ortho-positronium and the OH radical that meet by diffusion, and at this time, it is possible for the unpaired electrons of the parent OH radical and daughter o-Ps to be in a singlet state.

[0038] Thus, the change in S(t) observed during the ortho-positronium annihilation process exhibits oscillations due to the undulation seen in the change in the probability of existence of the singlet state, as shown in Figure 1. Consequently, AMOC measurements show a period twice that of the electron spin rotation period within the free radical. In other words, the hyperfine coupling constant a [Hz] of the electrons within the free radical can be obtained from the oscillation of S(t) observed in Figure 10.

[0039] Figures 11 and 12 show the results of AMOC measurements at 2.5°C and 0.6°C in water having a conventional cluster structure and a cluster structure according to the present invention, respectively. The S-parameters are normalized to the S-parameters at a positron age of -0.1 to 0.2 nanoseconds. The S(t) oscillations seen in Figures 10 and 11 are called quantum beats. When a water cluster has an asymmetric structure as shown in Figure 2, unpaired electrons in the OH radical are localized as usual, and S(t) oscillations are observed.

[0040] On the other hand, when a water cluster has a symmetrical structure as shown in Figure 1, the position of unpaired electrons in the OH radical is not determined (delocalized), and the oscillation of S(t) is not observed as shown in Figure 12.

[0041] The structure of the water cluster in this embodiment is preferably represented by the following formula (A).

[0042] [ka] [In equation (A), m, n, and l are integers from 0 to 30, m+n is an integer greater than or equal to 1. m+n+l is an integer between 10 and 30. [ka] This indicates a hydrogen bond.

[0043] In this embodiment, it is preferable that the water cluster is capable of capturing ions and / or ionic compounds by hydrogen bonding. Furthermore, if the water cluster in this embodiment is capable of capturing ions and / or ionic compounds by hydrogen bonding, it is preferable that the structure of the water cluster is represented by the following formula (B).

[0044] [ka] [In equation (B), o, p, and r are integers from 0 to 30, q is an integer between 1 and 30. o+p is an integer greater than or equal to 1, o+p+q+r are integers between 10 and 30. [ka] This indicates a hydrogen bond.

[0045] [Method for manufacturing water clusters] One embodiment of the present invention is a method for manufacturing water clusters, comprising the following steps (i) to (iii). In one embodiment of the present invention, water clusters are preferably manufactured by the manufacturing method of this embodiment in order to satisfy the relationship S1 ≤ S2, where S1 is the S parameter measured at 8°C by the AMOC method after a positron age of 2 nanoseconds, and S2 is the S parameter measured at 10°C. (i) A process to identify the cooling temperature [°C] and the storage time [day] corresponding to the cooling temperature, based on a predetermined correspondence between the S-parameter [-] in water measured by the AMOC method, the temperature of the water [°C], and the storage time [day] at the water temperature. (ii) A cooling step of cooling water to a temperature below the cooling temperature [°C], (iii) A storage step in which the water is stored at a temperature below the cooling temperature [°C] for a storage period [day] or longer after the cooling step.

[0046] (i) A specific step of identifying the cooling temperature [°C] and the storage time [day] corresponding to the cooling temperature. Step (i) is the step of determining the cooling temperature and the storage time corresponding to the cooling temperature. In this embodiment of the manufacturing method, water is stored at a predetermined temperature for a predetermined time or longer, but first the storage temperature (cooling temperature) and storage time are determined. The required storage time differs depending on the cooling temperature. The binding of H ions and / or OH ions to the surface of water clusters due to cooling can be confirmed from the pH change, and as an example, Figure 5 shows the pH change when stored at 2.5°C. From Figure 5, it can be seen that when stored at 2.5°C, it takes about a week for the binding of H ions and / or OH ions to the surface of water clusters to reach a saturation state. Figure 4 shows the pH change when water in which the cluster structure has been sufficiently eliminated at 45°C is cooled at a cooling rate of -0.5°C / hour. As can be seen from Figure 4, the cooling temperature is preferably less than 5°C.

[0047] First, the S-parameters are measured at a temperature of 10°C or higher. The water is stored at a predetermined cooling temperature T1[°C] for a predetermined period (referred to as the storage number of days). After storage, the S-parameters [-] in the water are measured using the AMOC method while the water temperature is increased, and it is confirmed whether the S-parameters decrease from T1[°C] to 10°C or higher to the previously measured S-parameters. The number of storage days at which no decrease in the S-parameters occurs from T1[°C] to 10°C or higher is identified as the storage time D1[day] corresponding to the cooling temperature T1[°C].

[0048] In a particular process, only one condition may be specified, or two or more conditions may be specified. That is, only a certain cooling temperature T1 [°C] and a storage time D1 [day] corresponding to that cooling temperature may be specified, or a different cooling temperature T2 [°C] and a storage time D2 [day] corresponding to that cooling temperature may be further specified.

[0049] (ii) Temperature cooling step of cooling the water to below the temperature cooling temperature [°C] Step (ii) is a step of cooling water to a temperature [°C] or lower than the cooling temperature [°C] specified in step (i). The method of cooling is not particularly limited.

[0050] (iii) A storage step in which the water is stored at a temperature below the cooling temperature [°C] for a storage period [day] or longer after the cooling step. Step (iii) is a step in which the water that has been cooled to a temperature below the cooling temperature [°C] in step (ii) is stored at a temperature below the cooling temperature [°C] for a storage time [day] or longer that corresponds to the cooling temperature specified in step (i).

[0051] The method of storage below the cooling temperature is not particularly limited; the product may be stored while being cooled using the same method as the initial cooling, or it may be stored while being cooled using a different method. The storage temperature should be below the cooling temperature, it may be a constant temperature, or it may fluctuate.

[0052] If the method for producing water clusters in this embodiment is a method for producing water clusters capable of capturing ions and / or ionic compounds by hydrogen bonding, it is preferable to further include the following step (iv).

[0053] (iv) A heating step in which the water is heated to a temperature of 5°C or higher after the storage step. Step (iv) is a step of heating the water stored in step (iii) to 5°C or higher. The method of heating to 5°C or higher is not particularly limited. The heating rate is not particularly limited.

[0054] [How to use water clusters] One embodiment of the present invention is a method for utilizing water clusters. The method of use of this embodiment is preferably a method for utilizing water clusters, which is one embodiment of the present invention, in industrial and / or medical applications.

[0055] One embodiment of the present invention, a water cluster, can increase the proton concentration in the solution by releasing protons from the water cluster structure at around 40°C. Simultaneously, OH- The ion concentration can also be increased. Therefore, a high proton concentration or OH - It can be useful in industrial applications where ion concentration is required, as well as in medical applications.

[0056] One embodiment of this invention, a water cluster, undergoes a structural change at around 40°C. This structural change is thought to occur in water molecules within living organisms as well. This could enable functional control of molecules with molecular structures surrounded by water molecules, such as biomolecules, in industrial and medical applications.

[0057] As described in Example 3 below, a water cluster, which is one embodiment of the present invention, may exhibit hysteresis in its S-parameter at temperatures of approximately 15-28°C. Since such reversible structural changes are thought to be due to ion desorption and adsorption, it can be usefully utilized in industrial applications where the manifestation of ion adsorption capacity is required.

[0058] One embodiment of the present invention, a water cluster, exhibits high proton conductivity due to its cluster structure. Since the cluster structure is stably maintained even at high temperatures, high proton conductivity can be achieved even at high temperatures, making it useful in industrial applications such as fuel cells.

[0059] One embodiment of the present invention, a water cluster, can adsorb ions onto its surface and exist stably. Normally, ions in aqueous solutions recombine and disappear, but by using the water cluster according to one embodiment of the present invention, ions can be stored stably and transported as they are. For example, by transporting them into a living organism, it is possible to increase the proton and OH ion concentrations within the organism. [Examples]

[0060] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0061] [Specific step of determining the cooling temperature [°C] and the storage time [day] corresponding to the cooling temperature] The S-parameter [-] in water, measured previously at 15°C, was 0.935. The S-parameter [-] in water was measured using the AMOC method while varying the water temperature under the following conditions. <Condition 1> Water at 25°C was cooled to 5°C and stored at 5°C or below for 18 days. After storage, the water was heated back up to 25°C. <Condition 2> Water at 25°C was cooled to 5°C and stored at 5°C or below for 64 days. After storage, the water was cooled to 25°C. The temperature rose. <Condition 3> Water at 25°C was cooled to 2.5°C and stored at 2.5°C or below for 10 days. After storage, the water was heated to 28°C, then cooled to 15°C, and finally heated to 25°C.

[0062] Figure 13 shows the measurement results of the S-parameter [-] in water measured by the AMOC method under conditions 1 to 3. The S-parameter is normalized to the S-parameter at a positron age of -0.1 to 0.2 nanoseconds. Under condition 1, the S-parameter decreased to a level similar to that of the S-parameter in water previously measured at 15°C when the temperature was increased from 5°C to 15°C. This indicates that the symmetric cluster structure changed and disappeared due to the temperature increase. On the other hand, under condition 2, the S-parameter did not decrease when the temperature was increased from 5°C to 15°C; rather, it increased. This indicates that the symmetric cluster structure was maintained. From conditions 1 and 2, it was determined that the storage time corresponding to a cooling temperature of 5°C is 64 days.

[0063] As shown in Figure 13, under condition 3, the S-parameter did not decrease during the temperature increase from 2.5°C to 15°C; rather, it increased. This indicates that the symmetrical cluster structure was maintained. From condition 3, it was determined that the storage time corresponding to a cooling temperature of 2.5°C is 10 days.

[0064] Furthermore, as shown in Figure 13, under condition 3, the S-parameter decreased when the temperature was raised to 28°C. Afterward, when the temperature was lowered to 15°C and then raised to 25°C, the S-parameter increased again. Thus, hysteresis in the S-parameter was observed between 15°C and 28°C. This indicates that some ions bound to the cluster surface detached at 28°C, and then re-bound to the cluster upon lowering the temperature, thereby reforming the symmetry of the cluster structure.

[0065] [Comparative Example 1] Similar to Condition 1, water at 25°C was cooled to 5°C and stored at 5°C or below for 18 days. As shown in Figure 13, in Comparative Example 1, S1 > S2, and water clusters were obtained in which the symmetrical structure changed when the temperature was raised.

[0066] [Example 1] Similar to Condition 2, water at 25°C was cooled to 5°C and stored at 5°C or below for 64 days. As shown in Figure 13, in Example 1, S1 ≤ S2, and water clusters were obtained in which the symmetrical structure was maintained even when the temperature was raised to 10°C or higher.

[0067] [Example 2] Similar to Condition 3, water at 2.5°C was cooled to 2.5°C and stored at 2.5°C or below for 10 days. As shown in Figure 13, in Example 2, S1 ≤ S2, and water clusters were obtained in which the symmetrical structure was maintained even when the temperature was raised above 10°C.

[0068] [pH measurement] When the pH of the water obtained in Example 2 was measured while raising the temperature to 45°C, the pH change shown in Figure 3 was observed. It was found that in the water obtained in Example 2, H ions and / or OH ions were sufficiently bound to the surface of the cluster structure to maintain the structure.

[0069] The water obtained in Example 1, like in Example 2, retains its symmetrical cluster structure even when the temperature is increased, suggesting that sufficient H ions and / or OH ions are bound to the surface of the cluster structure to maintain its structure. In other words, if the pH of the water obtained in Example 1 is measured in the same way as in Example 2, it is expected that a pH change similar to that shown in Figure 3 will be observed.

[0070] On the other hand, the water obtained in Comparative Example 1 shows a change in its symmetrical cluster structure as the temperature rises, and it disappears. This suggests that a sufficient amount of H ions and / or OH ions are not bound to the surface of the cluster structure. In other words, even if the pH of the water obtained in Comparative Example 1 is measured in the same way as in Example 2, it is expected that the same pH change as shown in Figure 3 will not be observed. [Explanation of symbols]

[0071] 100 devices 10 containers 20 SD 30 PAL 40 AMOC System (2D-MCA) 50 DBPA 60 SSD

Claims

1. A method for producing a water cluster having a structure in which H ions and / or OH ions are bonded to the surface of an aggregate of water molecules linked by hydrogen bonds, The water containing the aforementioned water cluster satisfies the relationship S1 ≤ S2, where S1 is the S-parameter measured at 8°C at a positron age of 2 nanoseconds or more by positron annihilation gamma-ray lifetime-momentum correlation (AMOC) and S2 is the S-parameter measured at 10°C. A method for producing water clusters, comprising the following steps (i) to (iii). (i) A process to identify a cooling temperature [°C] and a storage time [day] corresponding to the cooling temperature, based on a predetermined correspondence between the S-parameter [-] in water measured by the positron annihilation gamma-ray lifetime-momentum correlation (AMOC) method, the temperature of the water [°C], and the storage time [day] at the water temperature, (ii) A cooling step of cooling water to a temperature below the aforementioned cooling temperature [°C], (iii) A storage step in which the water is stored at a temperature below the cooling temperature [°C] for a storage time [day] or longer after the cooling step.

2. The method for producing a water cluster according to claim 1, wherein the water cluster is capable of capturing ions and / or ionic compounds by hydrogen bonding, and further comprises the following step (iv). (iv) A heating step in which the water is heated to a temperature of 5°C or higher after the storage step.

3. The method for producing a water cluster according to claim 1, wherein the structure of the water cluster is represented by formula (A). 【Chemistry 1】 [In equation (A), m, n, and l are integers from 0 to 30, m+n is an integer greater than or equal to 1, m + n + l are integers between 10 and 30. 【Chemistry 2】 This indicates a hydrogen bond.

4. The method for producing a water cluster according to claim 2, wherein the structure of the water cluster is represented by formula (B). 【Transformation 3】 [In equation (B), o, p, and r are integers from 0 to 30, q is an integer between 1 and 30. o + p is an integer greater than or equal to 1. o + p + q + r are integers between 10 and 30. 【Chemistry 4】 This indicates a hydrogen bond.

5. A method for utilizing water clusters produced by the water cluster manufacturing method described in any one of claims 1 to 4, Methods of using the water cluster for industrial and / or medical applications.

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