DE202022105194U1 - A system for the synthesis of KMgSO4Cl nanocrystallites - Google Patents

Abstract

A system for synthesizing KM ₉ SO ₄ Cl nanocrystallites, the system comprising:
a reaction chamber for the treatment of KCl and MgSO ₄ leading to a cationic-anionic process using H ₂ O to generate an interaction between cationic (K ⁺ , H ⁺ and Mg ⁺ ) and anionic (S ^- , O ^- and Cl ^- ) to allow ions, which leads to a charge-compensated aggregate;
a heating unit to evaporate H ₂ O using the applied temperature and the recombination of K ⁺ , Mg ⁺ , S ^- , O ^- and Cl- resulting in the formation of KMgSO ₄ Cl nanocrystallites; and
a Bruker X-ray diffractometer to characterize the resulting powder sample for its phase purity and crystallinity by X-ray powder diffraction (XRD).

Description

FIELD OF THE INVENTION

The present disclosure relates to the nanoarchitecture for the synthesis of nanocrystallites, more specifically to a system for the synthesis of KMgSO ₄ Cl nanocrystallites.

BACKGROUND OF THE INVENTION

The development of thermoluminescent dosimeters (TLD) and the associated nanoarchitecture is an important global challenge due to environmental and health issues. Sustainable TLD materials include rare earth-doped fluorides, borates, oxides, and sulfates. Of these, sulfates are known as TLD phosphors because of their extensive applications in personal radiation monitoring and as an outstanding photoluminescent material. In recent decades, nanoarchitectural methods for personal radiation monitoring systems have been developed and attracted increasing interest to solve the health problems caused by hazardous radiation. The defects and color centers in TLD materials are formed by irradiation, with the dopant ions acting as electron and hole traps.

As soon as the thermal energy is applied to the irradiated materials, visible light, the so-called ThermoLuminescence (TL) glow peak, occurs due to the recombination of electrons and holes in the capture centers. The TL performance depends on various parameters, e.g. on the nature of the host lattice, the irradiation source, the morphology, the dopant ions, the formation of defect centers, color centers and trap sites, etc. The valuable information responsible for the conversion of the crystallite's storage energy into TL glows is conveyed by kinetic parameters are shown leading to the nature of the TL spectrum. The CaSO ₄ :Dy and CaSO ₄ :Tm TL dosimeters belong to the family of sulfate-based phosphors, which are widely used in human applications due to their utility and low cost. The crystallites K ₂ Ca ₂ (SO ₄ ) ₃ :Eu, K ₃ Na(SO ₄ ) ₂ :Eu and LiNaSO ₄ :Eu are also known to be highly sensitive TL dosimeters.

In addition, it is reported that sulfate-based K ₂ SO ₄ -Na ₂ SO ₄ :Eu phosphors are more sensitive TL dosimeters than the known CaSO ₄ :Dy phosphors. The unique TL properties of K ₂ SO ₄ -Na ₂ SO ₄ :Eu are due to its ability to form defect centers, color centers and traps upon irradiation compared to CaSO ₄ :Dy TL dosimeters. The addition of halide ions to sulfate crystallites is known as halosulfate. The first halosulfate crystallite, Na ₆ Ca ₄ (SO ₄ ) ₆ F ₂ , was reported in 1939 and paved the way for the development of the halosulfate family. The detailed PL and TL study of the rare earth-doped halosulfate phosphors Na ₆ Pb4(SO4)6Cl ₂ , Na ₆ Cd4(SO4)6Cl ₂ , Na _{6 45} Ca _{3 55} (SO ₄ ) ₆ (F _x Cl _1-x ) _1.55 , Na ₃ (SO ₄ )F, and NaMg(SO ₄ )F have been studied and reported previously. A brief TL and PL analysis of rare earth ion-doped KZnSO ₄ Cl and KMgSO ₄ Cl phosphors was previously published by our group. In addition to the TL and PL properties, the occupancy of the dopant ion in the oxidation state +3 or +2 in the entire phosphor is an important parameter that determines the resulting light output. On the other hand, it can also be seen that the Eu(II) oxidation level of the dopant ions leads to better light yield. The presence of Eu(II) or Eu(III) in the host crystallites in the form of impure impurities or due to charge balancing by an oxygen ion at the chlorine site is the subject of extensive investigation.

In this study, a blue-red luminescent KMgSO ₄ Cl:Eu ^2+,3+ phosphor was prepared using a wet chemical method and the concept of nanoarchitecture behind the fabrication of nanostructures was explained. The basic photoluminescence (PL) and thermoluminescence (TL) properties have been described with reference to our previous report. The presence of oxidation states of the Eu ion was monitored using XPS analysis. The systematic TL response, kinetic parameters, and fading effect of the γ-irradiated KMgSO ₄ Cl:Eu ^3+,2+ phosphor have been studied and reported here. The detailed TL kinetic parameters such as geometric factors (µg), activation energies/trap depth (E), and frequency factor (s) of gamma-γ-irradiated KMgSO ₄ Cl:Eu phosphors were determined using the Chen peak shape method, the Ilich method or the initial rise method. The fading behavior of the KMgSO ₄ Cl:Eu phosphor after γ-ray irradiation was also shown. The correlated TL and PL mechanism was also presented to support the results obtained.

In view of the above, it is clear that a system for the synthesis of KMgSO ₄ Cl nanocrystallites is needed.

SUMMARY OF THE INVENTION

The present disclosure aims to provide a system for the synthesis of KMgSO ₄ Cl-Nano to provide crystallites using a wet-chemical process.

In one embodiment, a system for synthesizing KMgSO ₄ Cl nanocrystallites is disclosed. The system includes a reaction chamber for treating KCl and MgSO ₄ , resulting in a cationic-anionic process using H ₂ O to induce the interaction of cationic (K ⁺ , H ⁺ and Mg ⁺ ) and anionic (S ^- , O ^- and Cl ^- ) ions, resulting in a charge-compensated aggregate. The system further includes a heating unit to vaporize H ₂ O using the applied temperature and the recombination of K ⁺ , Mg ⁺ , S ^- , O ^- and Cl ^- , resulting in the formation of KMgSO ₄ Cl nanocrystallites. The system also includes a Bruker X-ray diffractometer to characterize the resulting powder sample in terms of its phase purity and crystallinity by X-ray powder diffraction (XRD).

In another embodiment, the interaction of the molecular springs specific to the nanoscale areas makes an indispensable contribution to the structure of the material.

In another embodiment, a bottom-up assembly method preferably involves a low-energy self-assembled process for the synthesis of KMgSO ₄ Cl nanocrystallites, using the concept of nanoarchitectural self-assembly for the synthesis of KMgSO ₄ Cl and KMgSO ₄ Cl:Eu phosphor Using the wet chemical method is used.

In another embodiment, the average activation energy (E _avg ) calculated by the Chen peakform method, the initial rise method and the Ilich method for γ-ray irradiated KMgSO ₄ Cl:Eu nanocrystallites is 0.89 , 1.10, and 0.98 eV for 450 K (i.e., peak-1), 486 K (i.e., peak-2), and 542 K (i.e., peak-3) GCD peaks, with the estimated trap levels at 0.89, 1.10, and 0.98 eV for the species are responsible for the TL glow curve.

A goal of the present disclosure is the development of nanoarchitecture, a self-assembly concept for the synthesis of nanocrystallites.

Another object of the present disclosure is to confirm the formation of KMgSO ₄ Cl:Eu phosphor with the symmetry class of monoclinic β structure with space group C2/m.

Another object of the present invention is to provide a rapid and inexpensive system for the synthesis of the KMgSO ₄ Cl:Eu _1m% phosphor using the wet-chemical method.

In order to further clarify the advantages and features of the present disclosure, a more detailed description of the invention is provided by reference to specific embodiments that are illustrated in the accompanying figures. It is understood that these figures represent only typical embodiments of the invention and therefore should not be considered as limiting the scope of the invention. The invention will be described and illustrated with additional specificity and detail with the accompanying figures.

character list

• 1 ein Blockdiagramm eines Systems zur Synthese von KMgSO₄Cl-Nanokristalliten in Übereinstimmung mit einer Ausführungsform der vorliegenden Offenbarung zeigt;
• 2 das Röntgenbeugungsmuster eines KMgSO₄Cl-Kristallits gemäß einer Ausführungsform der vorliegenden Offenbarung zeigt;
• 3 eine Tabelle 1 mit geschätzten kinetischen Parametern unter Verwendung der Chen-Peakform-Methode für mit γ-Strahlen bestrahlten KMgSO₄Cl: Eu-Leuchtstoff gemäß einer Ausführungsform der vorliegenden Offenbarung zeigt;
• 4 eine Tabelle 2 mit geschätzten kinetischen Parametern unter Verwendung der Initial Rise-Methode für mit γ-Strahlen bestrahlten KMgSO₄Cl: Eu-Leuchtstoff gemäß einer Ausführungsform der vorliegenden Offenbarung zeigt; und
• 5 eine Tabelle 3 mit geschätzten kinetischen Parameter eines mit γ-Strahlung bestrahlten KMgSO₄Cl: Eu-Leuchtstoffs gemäß einer Ausführungsform der vorliegenden Offenbarung nach der Methode von Ilich zeigt.

These and other features, aspects, and advantages of the present disclosure will be better understood when the following detailed description is read with reference to the accompanying figures, in which like characters represent like parts throughout the figures, wherein:

• 1 Figure 12 shows a block diagram of a system for synthesizing KMgSO ₄ Cl nanocrystallites in accordance with an embodiment of the present disclosure;
• 2 Figure 12 shows the X-ray diffraction pattern of a KMgSO ₄ Cl crystallite according to an embodiment of the present disclosure;
• 3 Table 1 shows estimated kinetic parameters using Chen peakform method for γ-ray irradiated KMgSO ₄ Cl:Eu phosphor according to an embodiment of the present disclosure;
• 4 Table 2 shows estimated kinetic parameters using the initial rise method for γ-ray irradiated KMgSO ₄ Cl:Eu phosphor according to an embodiment of the present disclosure; and
• 5 Figure 3 shows Table 3 with estimated kinetic parameters of a γ-irradiated KMgSO ₄ Cl:Eu phosphor according to an embodiment of the present disclosure according to the method of Ilich.

Those skilled in the art will understand that the elements in the figures are presented for simplicity and are not necessarily drawn to scale. For example, the flow charts illustrate the method of key steps to enhance understanding of aspects of the present disclosure. Furthermore, one or more components of the device may be represented in the figures by conventional symbols, and the figures show only the specific details relevant to the understanding of the embodiments of the present disclosure in order to provide the Not to overload figures with details that are readily apparent to those skilled in the art familiar with the present description.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the invention, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe the same. It should be understood, however, that no limitation on the scope of the invention is intended, and such alterations and further modifications to the illustrated system and such further applications of the principles of the invention set forth therein are contemplated as would occur to those skilled in the art invention would normally come to mind.

Those skilled in the art will understand that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be limiting.

When this specification refers to "an aspect," "another aspect," or the like, it means that a particular feature, structure, or characteristic described in connection with the embodiment is present in at least one embodiment included in the present disclosure. Therefore, the phrases "in one embodiment," "in another embodiment," and similar phrases throughout this specification may or may not all refer to the same embodiment.

The terms "comprises," "including," or other variations thereof are intended to cover non-exclusive inclusion such that a method or method that includes a list of steps includes not only those steps, but may also include other steps that are not expressly stated or pertaining to any such process or method. Likewise, any device or subsystem or element or structure or component preceded by "comprises...a" does not, without further limitation, exclude the existence of other devices or other subsystem or other element or other structure or other component or additional device or additional subsystems or additional elements or additional structures or additional components.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The system, methods, and examples provided herein are for purposes of illustration only and are not intended to be limiting.

Embodiments of the present disclosure are described in detail below with reference to the attached figures.

In 1 Illustrated is a block diagram of a system for synthesizing KMgSO ₄ Cl nanocrystallites according to an embodiment of the present disclosure. The system 100 includes a reaction chamber 102 for treating KCl and MgSO ₄ resulting in a cationic-anionic process using H ₂ O to promote the interaction of cationic (K ⁺ , H ⁺ and Mg ⁺ ) and anionic (S ^- , O ^- and Cl ^- ) ions, resulting in a charge-compensated aggregate.

In one embodiment, a heating unit 104 is coupled to the reaction chamber 102 to vaporize H ₂ O using the applied temperature and the recombination of K ⁺ , Mg ⁺ S ^- , O ^- and Cl ^- resulting in the formation of KMgSO ₄ Cl- Nanocrystallites leads.

In one embodiment, a Bruker X-ray diffractometer 106 is in communication with the heating unit 104 for characterizing the resulting powder sample for phase purity and crystallinity by X-ray powder diffraction (XRD).

In another embodiment, the interaction of the molecular springs specific to the nanoscale areas makes an indispensable contribution to the structure of the material.

In another embodiment, a bottom-up assembly method preferably involves a low-energy self-assembled process for the synthesis of KM ₉ SO ₄ Cl nanocrystallites, using the concept of nanoarchitectural self-assembly for the synthesis of KMgSO ₄ Cl- and KMgSO ₄ Cl:Eu- Phosphor using the wet chemical method is used.

In another embodiment, the average activation energy (Eavg) calculated by the Chen peakform method, the initial rise method, and the Ilich method for γ-ray irradiated KMgSO ₄ Cl :Eu nanocrystallites is 0.89, 1.10 and 0.98 eV for 450 K (i.e. peak-1), 486 K (i.e. peak-2) and 542 K (i.e. peak-3) GCD peaks, with the estimated trap levels at 0.89, 1.10 and 0.98 eV for the type of TL glow curve are responsible.

KMgSO ₄ Cl phosphors (pure and doped with Eu) are produced using the wet-chemical method. The detailed synthetic procedure is given in our reference. The chemical reaction for the synthesis of KMgSO ₄ Cl and KMgSO ₄ Cl:Eu is given in Equation 1 and Equation 2, respectively. KCI + MgSO ₄ → KMgSO ₄ Cl (1) KCI + MgSO ₄ + EuSO ₄ → KMgSO ₄ Cl:Eu (2)

The concept of nanoarchitecture was first proposed by Masakaza Aono in 2000. The design of functional materials using nanoscale units based on the principle of nanotechnology is called nanoarchitecture. The production of functional materials through nanoarchitecture takes place in several steps, including molecular synthesis. In this case, the wet-chemical method was used for the synthesis of KMgSO ₄ Cl and KMgSO ₄ Cl:Eu phosphor. The wet chemical method is a self-assembly process based on an equilibrium, which in our case produces a symmetrical and uniform structure. The raw materials KCl, MgSO ₄ , H ₂ O and EuSO ₄ are used for the synthesis of the KMgSO ₄ Cl phosphor. The process involves the interaction of cationic (K ⁺ , H ⁺ and Mg ⁺ ) and anionic (S ^- , O ^- and Cl ^- ) ions, resulting in a charge-balancing aggregate. H ₂ O is used to dissolve KCl and MgSO ₄ crystallites forming a homogeneous solution resulting in a cationic-anionic process. The interaction of the molecular springs, which are specific for the nanoscale areas, makes an indispensable contribution to the structure of the material. The H ₂ O is vaporized using the temperature and the recombination of K ⁺ , Mg ⁺ , S ^- , O ^- and Cl ^- leads to the assembly of KMgSO ₄ Cl ^- nanocrystallites. This method is called bottom-up assembly and is basically a non-energy consuming self-organized process. Therefore, the methods of nanoarchitecture are advantageous for fabricating hierarchical material structures from different nanobuilding blocks. The nanoarchitecture is a self-assembly concept for the synthesis of KMgSO ₄ Cl and KMgSO ₄ Cl:Eu phosphor using the wet chemical method.

Characterization methods

The resulting powder sample is analyzed for phase purity and crystallinity by X-ray powder diffraction (XRD) using a Bruker 106 X-ray diffractometer. Morphology analysis is performed with a PHI 700 Nano Scanning Auger Electron Microprobe (NanoSAM). Energy dispersive X-ray spectroscopy (EDS) to determine the individual elements of the resulting powder sample is performed using a Shimadzu SSX-550 scanning electron microscope. The PL analysis is recorded on a carry eclipse spectrophotometer at room temperature using a monochromatized xenon flash lamp as the excitation source. X-ray photoelectron spectroscopy (XPS) is measured with a PHI 5000 VersaProbe spectrometer using a monochromatic Al-Ka radiation source. TL glow curves are recorded with a Nucleonix Integrated Thermoluminescence Reader TLD10091 after the samples are irradiated at room temperature with γ-rays from a ⁶⁰ Co source at a rate of 0.995 kGy/h. The heating rate of 2°C/s is maintained during the TL measurement. The TL glow curve of commercial TLD-CaSO ₄ :Dy is also recorded under identical conditions for comparison.

2 12 shows the X-ray diffraction pattern of a KMgSO ₄ Cl crystallite according to an embodiment of the present disclosure. The X-ray diffraction pattern (XRD) of the synthesized KMgSO ₄ Cl nanocrystallite is in 2 shown. Crystalline product formation and phase purity are confirmed by comparison of the XRD pattern to ICCD file #074-0383. The symmetry class of KMgSO ₄ Cl follows a monoclinic β-structure with a space group of C2/m. The parameters of the unit cell are a = 19:7200, b = 16:2300, c = 9:5300 and β = 94.9200°. The number of formulas per unit cell, i.e. Z = 16 and the volume of the unit cell (V _c ) = 3038.89 Å3. The number of atomic positions per full unit cell (P/U) = 172 and the molar volume (Vm) = 114.40 cm ³ /mol. The hk I values of the KMgSO ₄ Cl crystallites are labeled with their respective XRD peaks and in 2 shown.

3 Table 1 shows the estimated kinetic parameters using the Chen peakform method for γ-ray irradiated KMgSO ₄ Cl:Eu phosphor in accordance with an embodiment of the present disclosure. The estimated values of the geometric factor (µg), activation energy/trap depth (E), and frequency factor (s) using Chen's equations τ, δ, and ω are summarized in Table 1.

4 Table 2 shows the estimated kinetic parameters using the initial rise method for γ-irradiated KMgSO ₄ Cl:Eu phosphor in accordance with an embodiment of the present disclosure. The estimated activation energy/capture depth (E) values obtained using the IR method for irradiated KMgSO ₄ Cl:Eu ^1m% Lumin substance are summarized in Table 2.

5 Table 3 shows the estimated kinetic parameters of a γ-ray irradiated KMgSO ₄ Cl:Eu phosphor by the Ilich method according to an embodiment of the present disclosure. The estimated activation energy/trap depth (E) and frequency factor (s) values of the irradiated KMgSO ₄ Cl:Eu phosphor by the Ilich method are summarized in Table 3. The estimated activation energy (E) and frequency factor (s) values also agree well with previous reports for halosulfate phosphors.

The KMgSO ₄ Cl:Eu phosphor was synthesized using a wet-chemical method, and the nanoarchitectural concept behind the fabrication of the nanostructures was explained. Compound formation was demonstrated using X-ray diffraction analysis (XRD) and the presence of individual elements using energy-dispersive X-ray spectroscopy (EDS). The spherical but faceted, highly agglomerated morphology of the KMgSO ₄ Cl nanocrystallites was verified by NanoSAM analysis. The band gap (Eg) value of KMgSO ₄ Cl was found to be 3.4±0.1 eV from analysis of the diffuse reflectance spectrum. Photoluminescence (PL) analysis shows that Eu is present in both the divalent (Eu ²⁺ ) and trivalent (Eu ³⁺ ) oxidation states. The two oxidation states were detected by XPS analysis as EuCl ²⁺ and EuCl ³⁺ species, essentially as Eu(II) and Eu(III) oxidation states, respectively. The TL glow curve consists of a broad main band at 450 K and a small peak at 542 K. The TL glow curve was deconvoluted to calculate the kinetic parameters and the quasi-continuous distribution of the trap levels. The kinetic parameters of the TL glow curve were estimated using the Chen peak form method, the Ilich method, and the initial slope method, respectively. The fading response shows that the TL intensity was reduced to 25-30% during the 30 day storage period.

The figures and the preceding description give examples of embodiments. Those skilled in the art will understand that one or more of the elements described may well be combined into a single functional element. Alternatively, certain elements can be broken down into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, the order of the processes described herein may be changed and is not limited to the manner described herein. Additionally, the actions of a flowchart need not be performed in the order shown; Also, not all actions have to be carried out. Also, the actions that are not dependent on other actions can be performed in parallel with the other actions. The scope of the embodiments is in no way limited by these specific examples. Numerous variations are possible, regardless of whether they are explicitly mentioned in the description or not, e.g. B. Differences in structure, dimensions and use of materials. The scope of the embodiments is at least as broad as indicated in the following claims.

Advantages, other benefits, and solutions to problems have been described above with respect to particular embodiments. However, the benefits, advantages, problem solutions, and components that can cause an advantage, benefit, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all claims.

reference list

100

A system for the synthesis of KMgSO4Cl nanocrystallites.

102

reaction chamber

104

heating unit

106

Bruker X-ray diffractometer

Claims (4)

A system for synthesizing KM ₉ SO ₄ Cl nanocrystallites, the system comprising: a reaction chamber for treating KCl and MgSO ₄ leading to a cationic-anionic process using H ₂ O to generate an interaction between cationic (K ⁺ , H ⁺ and Mg ⁺ ) and anionic (S ^- , O ^- and Cl ^- ) ions, resulting in a charge-compensated aggregate; a heating unit to evaporate H ₂ O using the applied temperature and the recombination of K ⁺ , Mg ⁺ , S ^- , O ^- and Cl- resulting in the formation of KMgSO ₄ Cl nanocrystallites; and a Bruker X-ray diffractometer to characterize the resulting powder sample for its phase purity and crystallinity by X-ray powder diffraction (XRD). system after claim 1 , whereby the interaction of the molecular springs specific to the nanoscale areas makes an indispensable contribution to the structure of the material. system after claim 1 , wherein a bottom-up assembly method preferably involves a non-energy consuming, self-assembled process for synthesizing KMgSO ₄ Cl nanocrystallites using the nanoarchitectural self-assembly concept for synthesizing KMgSO ₄ Cl and KMgSO ₄ Cl:Eu phosphor a wet-chemical process is used. system after claim 1 , where the average activation energy (Eavg) calculated using the Chen peak shape method, the initial slope method, and the Ilich method for γ-ray irradiated KMgSO4Cl:Eu nanocrystallites are 0. 89, 1.10, and 0.98 eV for 450 K (i.e. peak-1), 486 K (i.e. peak-2), and 542 K (i.e. peak-3) GCD peaks, with the estimated trap levels at 0.89, 1.10, and 0.98 eV for the type of TL glow curve are responsible.

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