Method for synthesizing calcium carbonate nanoparticles

Abstract

A method for synthesizing calcium carbonate nanoparticles comprising forming a calcium chloride solution, forming a mixture by adding polyacrylic acid and ethylenediaminetetraacetic acid with a weight ratio of 1:1 to the calcium chloride solution, forming a sodium carbonate solution, forming a calcium carbonate suspension comprising forming a reaction mixture by adding the sodium carbonate solution to the mixture, forming a calcium carbonate slurry by filtering the calcium carbonate suspension through a filter with a pore size of 50-150 nm, forming calcium carbonate aggregates by drying the calcium carbonate slurry at a temperature level of 100- 120 °C, forming a first grinded calcium carbonate particles by grinding the calcium carbonate aggregates using a pin mill, forming a second grinded calcium carbonate particles by grinding the first grinded calcium carbonate particles using a ball mill, and forming the calcium carbonate nanoparticles by grinding the second grinded calcium carbonate particles using a jet mill.

Description

METHOD FOR SYNTHESIZING CALCIUM CARBONATE NANOPARTICLESTECHNICAL FIELD

[0001] The present disclosure is generally related to an exemplary method for synthesizing exemplary calcium carbonate nanoparticles, and more particularly to an exemplary method for synthesizing exemplary calcium carbonate nanoparticles with calcite phase and less than 100 nm in size using an exemplary chemical bath deposition process.BACKGROUND

[0002] Calcium carbonate (CaCOs), a highly prevalent biomineral, has garnered significant interest due to its extensive utilization in various industrial sectors, including paper manufacturing, rubber production, plastics industry, and paint formulation. Utilization of CaCOs particles may be contingent upon several factors, including their structure, morphology, size, brightness, specific surface area, oil absorption capacity, chemical purity, and more. Of these factors, particle morphology is of crucial importance; thus, controlling shape and size of CaCOs crystals may be mandatory with respect to different applications.

[0003] Calcium carbonate may exist in three distinct polymorphic variations, namely calcite, aragonite, and vaterite. Among these, calcite is recognized as the most stable and least soluble form of calcium carbonate. Formation of any of these polymorphic forms may be strictly contingent upon certain variables, including supersaturation, temperature, and pH level of reaction mixture. On the other hand, the necessity to produce calcium carbonate with specific morphology, structure, and particle size is crucial, given its extensive utilization across multiple industries. Thus, there is need to develop facile synthesis methods for controlled production ofhighly pure calcium carbonate particles with diverse shapes, sizes (specially nanosized particles), morphologies, and polymorphs on a larger scale.SUMMARY

[0004] This summary is intended to provide an overview of the subject matter of the present disclosure, and is not intended to identify essential elements or key elements of the subject matter, nor is it intended to be used to determine the scope of the claimed implementations. Its sole purpose is to present some concepts of one or more exemplary aspects in a simplified form as a prelude to the more detailed description that is presented later. The proper scope of the present disclosure may be ascertained from the claims set forth below in view of the detailed description below and the drawings.

[0005] One or more exemplary embodiments describe an exemplary method for synthesizing exemplary calcium carbonate nanoparticles. Exemplary method may comprise forming an exemplary calcium chloride solution by dissolving calcium chloride in water with an exemplary concentration of 0.1-0.5 M, forming an exemplary mixture by adding polyacrylic acid (PAA) and ethylenediaminetetraacetic acid (EDTA) with an exemplary weight ratio (PAA:EDTA) of 1:1 to an exemplary calcium chloride solution, forming an exemplary sodium carbonate solution by dissolving sodium carbonate in water with an exemplary concentration of 0.1-0.5 M, forming an exemplary calcium carbonate suspension, forming an exemplary calcium carbonate slurry by filtering an exemplary calcium carbonate suspension through an exemplary rotating silicon carbide (SiC) filter with an exemplary pore size between 50 nm and 150 nm, forming exemplary calcium carbonate aggregates by drying an exemplary calcium carbonate slurry in an exemplary rotary dryer with an exemplary temperature level between 100 °C and 120 °C for an exemplary time duration between 100 minutes and 120 minutes, forming an exemplary first grinded calcium carbonate particles by grinding exemplary calciumcarbonate aggregates using an exemplary pin mill, forming an exemplary second grinded calcium carbonate particles by grinding an exemplary first grinded calcium carbonate particles using an exemplary ball mill, forming exemplary calcium carbonate nanoparticles with an average particle size between 20 nm and 150 nm by grinding an exemplary second grinded calcium carbonate particles using an exemplary jet mill.

[0006] In an exemplary embodiment, forming an exemplary calcium carbonate suspension may include forming an exemplary reaction mixture with an exemplary pH level of 8.5-9 by adding an exemplary sodium carbonate solution, with an exemplary volume flow rate between 1 L / min and 5 L / min, to an exemplary mixture; and mixing an exemplary reaction mixture with an exemplary rotation speed between 1200 rpm and 1500 rpm for an exemplary time duration between 90 minutes and 120 minutes. In an exemplary embodiment, exemplary calcium carbonate nanoparticles may comprise PAA with an exemplary concentration of 0.1 -0.5% (w / w) and EDTA with a concentration of 0.1-0.5% (w / w).

[0007] This Summary may introduce a number of concepts in a simplified format; the concepts are further disclosed within the “Detailed Description” section. This Summary is not intended to configure essential / key features of the claimed subject matter, nor is intended to limit the scope of the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The novel features which are believed to be characteristic of the present disclosure, as to its structure, organization, use and method of operation, together with further objectives and advantages thereof, will be better understood from the following drawings in which an exemplary embodiment will now be illustrated by way of example. It is expressly understood, however, that the drawings are for the purpose of illustration and description only and are notintended as a definition of the limits of the present disclosure. Exemplary embodiments will now be described by way of example in association with the accompanying drawings in which:

[0009] FIG. 1 illustrates flowchart of an exemplary method for synthesizing exemplary calcium carbonate nanoparticles, consistent with one or more exemplary embodiments of the present disclosure;

[0010] FIG. 2 illustrates a schematic representation of an exemplary reaction for forming calcium carbonate by reacting sodium carbonate with calcium chloride, consistent with one or more exemplary embodiments of the present disclosure;

[0011] FIG. 3 illustrates a plot of XRD pattern analysis of exemplary calcium carbonate nanoparticles, consistent with one or more exemplary embodiments of the present disclosure;

[0012] FIG. 4 illustrates a plot of XRD pattern analysis of exemplary calcium carbonate nanoparticles revealing an exemplary composition comprising a mixture of aragonite and calcite phases, consistent with one or more exemplary embodiments of the present disclosure; and

[0013] FIG. 5 illustrates transmission electron microscopy (TEM) images of exemplary calcium carbonate nanoparticles, consistent with one or more exemplary embodiments of the present disclosure.DETAILED DESCRIPTION

[0014] In the following detailed description, numerous specific details are set forth by way of examples to provide a thorough understanding of the relevant teachings related to the exemplary embodiments. However, it should be apparent that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and / or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.

[0015] The following detailed description is presented to enable a person skilled in the art to make and use the methods and devices disclosed in one or more exemplary embodiments of the present disclosure. For purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that these specific details are not required to practice the disclosed exemplary embodiments. Descriptions of specific exemplary embodiments are provided only as representative examples. Various modifications to the exemplary implementations will be plain to one skilled in the art, and the general principles defined herein may be applied to other implementations and applications without departing from the scope of the present disclosure. The present disclosure is not intended to be limited to the implementations shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.

[0016] Disclosed herein is an exemplary cost-effective method for producing exemplary calcium carbonate nanoparticles less than 100 nm in size while significantly reducing the level of impurities, such as Manganese (Mn) and iron (Fe). In an exemplary embodiment, chemical bath deposition may be used for synthesizing exemplary calcium carbonate nanoparticles with a diameter less than about 100 nm. In an exemplary embodiment, “chemical bath deposition” may refer to a process where exemplary precursor compounds may be dissolved into an exemplary liquid bath. Exemplary precursors may react within an exemplary liquid bath to form nanoparticles, which may precipitate out of an exemplary solution and remain suspended in an exemplary solution. An exemplary chemical bath deposition method may be advantageous due to its ability to control particle size and distribution by adjusting exemplary parameters, such as temperature, pH, concentration, and reaction time.

[0017] FIG. 1 illustrates flowchart of exemplary method 100 for synthesizing exemplary calcium carbonate nanoparticles, consistent with one or more exemplary embodiments of thepresent disclosure. In an exemplary embodiment, an exemplary method may include: forming an exemplary calcium chloride solution by dissolving calcium chloride in water with a concentration between about 0.1 M and 0.5 M (step 102); forming an exemplary mixture by adding poly aery lie acid (PAA) and ethylenediaminetetraacetic acid (EDTA) with a weight ratio (PAA:EDTA) of about 1:1 to an exemplary calcium chloride solution (step 104); forming an exemplary sodium carbonate solution by dissolving sodium carbonate in water with a concentration between about 0.1 M and 0.5 M (step 106); forming an exemplary calcium carbonate suspension (step 108); forming an exemplary calcium carbonate slurry by filtering an exemplary calcium carbonate suspension through an exemplary filter with a pore size between about 50 nm and 60 nm (step 110); forming exemplary calcium carbonate aggregates by drying an exemplary calcium carbonate slurry at a temperature level between about 100 °C and 120 °C (step 112); forming exemplary first grinded calcium carbonate particles by grinding exemplary calcium carbonate aggregates using an exemplary pin mill (step 114); forming exemplary second grinded calcium carbonate particles by grinding exemplary first grinded calcium carbonate particles using an exemplary ball mill (step 116); and forming exemplary calcium carbonate nanoparticles by grinding exemplary second grinded calcium carbonate particles using an exemplary jet mill (step 118).

[0018] In further detail with respect to step 102, step 102 may comprise forming an exemplary calcium chloride solution by dissolving calcium chloride in water with a concentration between about 0.1 M and 0.5 M. In an exemplary embodiment, dissolving calcium chloride in water with a concentration between about 0.1 M and 0.5 M may include adding calcium chloride powder (with a purity of about 99-99.9% (w / w)) in an exemplary water with a concentration of about 0.5 M (with respect to an exemplary final volume of an exemplary calcium chloride solution), in an exemplary container. An exemplary container may include,but is not limited to, beakers, tins, flasks, tanks, bottles, buckets, basins, bowls, vials, tubes, barrels, cannisters, etc. In an exemplary embodiment, an exemplary water used for forming an exemplary calcium chloride solution may include distilled water, double-distilled water, or ultrapure water. “Ultrapure water” may refer to a water that has been purified using a combination of ultrafiltration technologies and ultraviolet photo-oxidation system. In an exemplary embodiment, dissolving calcium chloride powder (with a purity of about 99.5% (w / w)) in an exemplary water with a concentration of about 0.5 M in an exemplary container may include dissolving calcium chloride (with a purity of about 99.5% (w / w)) in distilled water with a final concentration of about 0.5 M, in an exemplary solution tank, while stirring, e.g., using a magnetic stirrer or an agitation machine (with a speed between about 500 rpm and 600 rpm), for a time duration of about 60-90 minutes at a temperature level of about 25-35 °C.

[0019] In further detail with respect to step 104, step 104 may include forming an exemplary mixture by adding PAA and EDTA with a weight ratio (PAA:EDTA) of about 1:1 to an exemplary calcium carbonate solution. In an exemplary embodiment, adding PAA and EDTA with a weight ratio (PAA:EDTA) of about 1:1 to an exemplary calcium carbonate solution may include adding PAA powder and EDTA powder to an exemplary calcium carbonate solution in an exemplary container (e.g., an exemplary solution tank) so that final concentration of each of PAA and EDTA may be about 0.5% (w / w) with respect to final weight of exemplary calcium carbonate nanoparticles.

[0020] In further detail with respect to step 106, step 106 may include forming an exemplary sodium carbonate solution by dissolving sodium carbonate in water with a concentration between about 0.1 M and 0.5 M. In an exemplary embodiment, dissolving sodium carbonate in water with a concentration between about 0.1 M and 0.5 M may include adding sodium carbonate powder (with a purity of about 98-99.9% (w / w)) in an exemplarywater with a concentration of about 0.5 M (with respect to an exemplary final volume of an exemplary sodium carbonate solution), in an exemplary container (e.g., an exemplary solution tank). In an exemplary embodiment, an exemplary water used for forming an exemplary sodium carbonate solution may include distilled water, double-distilled water, or ultrapure water. In an exemplary embodiment, dissolving sodium carbonate powder (with a purity of about 98% (w / w)) in an exemplary water with a concentration of about 0.5 M in an exemplary container may include dissolving sodium carbonate in distilled water with a final concentration of about 0.5 M, in an exemplary solution tank, while stirring, e.g., using a magnetic stirrer or an agitation machine (with a speed between about 500 rpm and 600 rpm), for a time duration of about 60-90 minutes at a temperature level of about 25-35 °C.

[0021] In further detail with respect to step 108, step 108 may include forming an exemplary calcium carbonate suspension. In an exemplary embodiment, forming an exemplary calcium carbonate suspension may include: forming an exemplary reaction mixture may include: forming a reaction mixture with a pH level of about 8.5-9 (in a reactor) by adding an exemplary sodium carbonate solution, with a volume flow rate between about 1 L / min and 5 L / min, to an exemplary mixture (using exemplary steel nozzles); and mixing an exemplary reaction mixture with a rotation speed between 1200 rpm and 1500 rpm for a time duration between 90 minutes and 120 minutes. FIG. 2 illustrates a schematic representation of exemplary reaction 200 for forming calcium carbonate 202 by reacting sodium carbonate 204 with calcium chloride 206, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, forming an exemplary reaction mixture with a pH level of about 8.5-9 (in a reactor) may include: monitoring pH level of an exemplary reaction mixture continuously using an exemplary pH meter; and adjusting inflow rate and / or concentration of sodium carbonate solution to adjust / maintain pH level at about 8.5-9. In anexemplary embodiment, mixing an exemplary reaction mixture with a rotation speed between 1200 rpm and 1500 rpm for a time duration between 90 minutes and 120 minutes may include mixing / shaking an exemplary reaction mixture with a rotation speed between about 1200 rpm for a time duration between 90 minutes and 120 minutes, using a magnetic stirrer or an agitation machine.

[0022] In further detail with respect to step 110, step 110 may include forming an exemplary calcium carbonate slurry by filtering an exemplary calcium carbonate suspension through an exemplary filter with a pore size between about 50 nm and 60 nm. In an exemplary embodiment, filtering an exemplary calcium carbonate suspension through an exemplary filter with a pore size between about 50 nm and 60 nm may include filtering an exemplary calcium carbonate suspension through a rotating silicon carbide (SiC) filter with a pore size between about 50 nm and 60 nm and a rotation speed between about 2 rpm and 3 rpm. In an exemplary embodiment, “SiC filter” may refer to a specialized piece of equipment used in industrial processes, particularly in the field of metallurgy and material science. An exemplary silicon carbide filter may serve as a durable and efficient medium for filtering out impurities or particulates from a substance. Rotation aspect of an exemplary SiC filter may help to increase efficiency of filtration by moving an exemplary filter through an exemplary substance, allowing more material to come into contact with it.

[0023] In further detail with respect to step 112, step 112 may include forming exemplary calcium carbonate aggregates by drying an exemplary calcium carbonate slurry at a temperature level between about 100 °C and 120 °C. In an exemplary embodiment, drying an exemplary calcium carbonate slurry at a temperature level between about 100 °C and 120 °C may include drying an exemplary calcium carbonate slurry in an exemplary rotary dryer witha temperature level between about 100 °C and 120 °C for a time duration between about 100 minutes and 120 minutes.

[0024] In further detail with respect to step 114, step 114 may include forming exemplary first grinded calcium carbonate particles by grinding exemplary calcium carbonate aggregates using an exemplary pin mill. In an exemplary embodiment, “pin mill” may refer to a type of grinding mill that may utilize pins to crush or grind materials into fine particles. An exemplary pin mill may operate by employing a series of concentric discs, each fitted with numerous pins, that rotate at high speeds. Exemplary pins may interact with exemplary particles as they travel through an exemplary mill, reducing their size through impact and shear forces. In further detail with respect to step 114, an exemplary pin mill equipped with high-speed motors, adjustable grinding pins, and a dynamic air classifier may be used for grinding exemplary calcium carbonate aggregates. In an exemplary embodiment, dimensions of an exemplary pin mill may be determined based on the quantity of exemplary calcium carbonate aggregates that require processing. Nevertheless, in an exemplary embodiment, an exemplary pin mill measuring approximately 1-2 meters in diameter may be employed in a medium-sized production facility. In an exemplary embodiment, grinding exemplary calcium carbonate aggregates in an exemplary pin mill may include: i) adjusting motor speed and pin configuration (e.g., an exemplary size of exemplary grinding pins may vary from 0.5 mm to 2 cm in diameter, and an exemplary speed at which exemplary pins rotate may be between 1000 to 2000 rpm); ii) feeding exemplary calcium carbonate aggregates into an exemplary feed hopper of an exemplary pin mill at a predetermined rate (an exemplary feed rate into an exemplary pin mill may be controlled such that it may not overload or underload an exemplary mill and may range from 1 kg / min to 500 kg / h); and iii) collecting exemplary first grinded calcium carbonate particles obtained from an exemplary pin mill.

[0025] In further detail with respect to step 116, step 116 may include forming exemplary second grinded calcium carbonate particles by grinding exemplary first grinded calcium carbonate particles using an exemplary ball mill. In an exemplary embodiment, “ball mill” may refer to a type of grinding mill, specifically designed to grind and blend materials for use in various processes, such as mineral dressing processes, paints, pyrotechnics, ceramics, and selective laser sintering. An exemplary ball mill may operate on the principle of impact and attrition: size reduction may be achieved by an exemplary grinding media's impact and sliding motion against both an exemplary material to be ground and walls of cylinder. Internal cascading effect of an exemplary ball mill may reduce an exemplary material to a fine powder over a period of several hours.

[0026] In an exemplary embodiment, grinding exemplary first grinded calcium carbonate particles using an exemplary ball mill may include: i) loading exemplary first grinded calcium carbonate particles (e.g., 700-1000 Kg) into an exemplary ball mill; ii) adjusting an exemplary ball mill’s parameters (e.g., size of exemplary balls used in an exemplary ball mill may be about 3-15 cm, and ball-to-powder ratio (BPR) in an exemplary ball milling procedure may be adjusted to at least 10: 1 (mass of balls to mass of powder)); and iii) collecting exemplary second grinded calcium carbonate particles after a predetermined time duration (e.g., an exemplary time duration for ball milling of about 700-1000 Kg calcium carbonate particles may be about 90-120 minutes).

[0027] In further detail with respect to step 118, step 118 may include forming exemplary calcium carbonate nanoparticles by grinding exemplary second grinded calcium carbonate particles using an exemplary jet mill. In an exemplary embodiment, grinding exemplary second grinded calcium carbonate particles using an exemplary jet mill may include: i) loading exemplary second grinded calcium carbonate particles into an exemplary jet mill; ii) adjustingexemplary parameters of an exemplary jet mill (e.g., feed rate that may range from 5 Kg to 500Kg, and classifier speed); and iii) collecting exemplary calcium carbonate nanoparticles that may have an average particle size of about 100 nm.EXAMPLES

[0028] Hereinafter, one or more exemplary embodiments will be described in further detail with reference to examples. It will be obvious to a person having ordinary skill in the art that these examples may be for illustrative purposes only and are not to be interpreted to limit the scope of the present disclosure.Example 1: Synthesis of Calcium Carbonate Nanoparticles

[0029] In this example, exemplary calcium carbonate nanoparticles were synthesized based on an exemplary process similar to method 100. To synthesize exemplary calcium carbonate nanoparticles, first an exemplary calcium chloride solution with a concentration of about 0.5 M may be prepared in a solution tank. In an exemplary embodiment, an exemplary calcium chloride solution may be prepared by dissolving calcium chloride powder (with a purity of about 99.5% (w / w)) in distilled water such that the final concentration of calcium chloride may be about 0.5 M by final volume of the calcium chloride solution, followed by stirring at about 500-600 rpm for about 60 minutes at a temperature level of about 25-35 °C. For example, to prepare about 50 L of 0.5 M calcium chloride solution, 3675.5 g of CaC12.2H2O (with a molecular weight: 147.02) may be dissolved in 25 L of deionized or distilled water using a magnetic stirrer with a speed range of between 500 rpm and 600 rpm. Then, about 25 L of distilled / deionized water may be added to an exemplary calcium chloride solution until the volume reaches about 50 L.

[0030] Then, polyacrylic acid (PAA) and ethylenediaminetetraacetic acid (EDTA) (both with a concentration of about 0.5% (w / w) by final weight of exemplary calcium carbonate nanoparticles) may be added to an exemplary calcium chloride solution to form an exemplary mixture (similar to an exemplary mixture set forth in step 104 of method 100). On the other hand, an exemplary sodium carbonate solution with a concentration of about 0.5 M may be prepared in a solution tank. In an exemplary embodiment, an exemplary sodium carbonate solution may be prepared by dissolving sodium carbonate powder (with a purity of about 98% (w / w)) in distilled water such that the final concentration of sodium carbonate may be about 0.5 M by final volume of the sodium carbonate solution, followed by stirring at about 500-600 rpm for about 60 minutes at temperature level of about 25-35 °C.

[0031] Afterwards, an exemplary calcium carbonate suspension may be prepared in a reactor by adding the formed sodium carbonate solution, with a volume flow rate between 1 L / min and 5 L / min (e.g., using steel nozzles of an exemplary reactor), to an exemplary mixture within a time duration of about 60 minutes. An exemplary suspension may be mixed at a rotation speed of about 1200 rpm for a time duration of about 30 minutes. Next, an exemplary suspension may be filtered through a rotating silicon carbide (SiC) filter with a pore size between about 50 nm and 60 nm and rotating speed between about 2 rpm and 3 rpm, resulting in production of an exemplary slurry with a moisture content between 10% and 20%. An exemplary produced slurry may be dried using a rotary dryer with a temperature level between 100 °C and 120 °C.

[0032] An exemplary slurry may thereafter be dried using an exemplary rotary dryer adjusted to a temperature level between about 100 °C and 120 °C to form calcium carbonate aggregates. To form calcium carbonate nanoparticles with average particle size of about 100 nm, exemplary calcium carbonate aggregates may undergo 3 phases of grinding using anexemplary pin mill, an exemplary ball mill, and an exemplary get mill, respectively. For this purpose, first a pin mill equipped with high-speed motors, adjustable grinding pins, and a dynamic air classifier may be selected. The size of an exemplary pin mill may depend on an exemplary volume of calcium carbonate aggregates that need to be processed. However, in an exemplary embodiment, for a medium- sized factory, an exemplary pin mill with a diameter of about 1-2 meters may be used. In an exemplary embodiment, to grind calcium carbonate aggregates in a pin mill, first one or more exemplary parameters of an exemplary pin mill, such as motor speed and pin configuration may be adjusted (e.g., an exemplary size of exemplary grinding pins may vary from 0.5 mm to 2 cm in diameter, and an exemplary speed at which exemplary pins rotate may be between 1000 to 2000 rpm). Then, exemplary calcium carbonate aggregates may be fed into feed hopper of an exemplary pin mill at a predetermined rate (an exemplary feed rate into an exemplary pin mill may be controlled such that it may not overload or underload an exemplary mill and may range from 1 kg / min to 500 kg / h). Finally, exemplary calcium carbonate particles obtained from an exemplary pin mill may be collected.

[0033] In an exemplary embodiment, exemplary calcium carbonate particles obtained from an exemplary pin mill may be grinded using an exemplary ball mill. In an exemplary embodiment, grinding calcium carbonate particles using an exemplary ball mill may be started by loading exemplary calcium carbonate particles (e.g., 700-1000 Kg) into an exemplary ball mill. One or more exemplary parameters of an exemplary ball mill may be adjusted; for example, size of balls used in an exemplary ball mill may be about 3-15 cm, and ball-to-powder ratio (BPR) in an exemplary ball milling procedure may be adjusted to at least 10:1 (mass of balls to mass of powder). Exemplary grinded calcium carbonate particles may be collected after a predetermined time duration (e.g., an exemplary time duration for ball milling of about 700-1000 Kg calcium carbonate particles may be about 90-120 minutes).

[0034] In an exemplary embodiment, following an exemplary grinding process with an exemplary ball mill, exemplary calcium carbonate particles collected from an exemplary ball mill may be grinded using an exemplary jet mill. In an exemplary embodiment, grinding calcium carbonate particles using an exemplary jet mill may be accomplished by loading exemplary calcium carbonate particles into an exemplary jet mill. An exemplary jet milling process may be followed by adjusting one or more exemplary parameters of an exemplary jet mill, such as feed rate that may range from 0.5 Kg to 500 Kg. Finally, calcium carbonate nanoparticles having an average particle size of about 100 nm may be collected from an exemplary jet mill.Example 2: Characterization of Calcium Carbonate Nanoparticles

[0035] In this example, exemplary produced calcium carbonate nanoparticles in “Example 1” were characterized by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD) analysis. Particle size and morphology were examined using transmission electron microscopy (TEM), revealing particles with dimensions less than 100 nm, and exhibiting a predominantly spherical shape. Furthermore, X-Ray Fluorescence (XRF) analysis was employed to assess purity of exemplary synthesized nanoparticles, which was determined to exceed 98%.

[0036] An exemplary product synthesized through an exemplary method similar to method 100 (as set forth in Example 1) may exhibit a crystalline structure, as evidenced by exemplary results of XRD pattern analysis which may clearly indicate the presence of crystal calcite. FIG. 3 illustrates plot 300 of XRD pattern analysis of exemplary calcium carbonate nanoparticles, consistent with one or more exemplary embodiments of the present disclosure. In further detail with respect to plot 300, results from the XRD analysis demonstrated that anexemplary phase of calcium carbonate nanoparticles synthesized via an exemplary method similar to method 100 may be calcite. Notably, no phase impurity was detected in this analysis. Furthermore, the main characteristic peak of an exemplary calcite phase, observed at an angle of 29=29.5°, aligns perfectly with reference peak.

[0037] Furthermore, the absence of any detected peaks from exemplary precursors used may suggest a thorough utilization of these precursors an exemplary reaction of nano-CaCCh production. To verify the presence of any other impurities quantitatively and to corroborate XRD analysis results on exemplary synthesized CaCCh compound, XRF analysis was conducted. Table 1 below shows results of XRF analysis of exemplary produced calcium carbonate nanoparticles.Table 1:X-ray fluorescence (XRF) analysis results of exemplary calcium carbonate nanoparticles, consistent with one or more exemplary embodiments of the present disclosure.

[0038] Exemplary results set forth in Table 1 may indicate the presence of exemplary impurities, such as SiCh, SO3, MgO, Na2O, Cl, Fe2O3. These impurities collectively constitute about 1.5% of the total composition of exemplary produced nano-CaCCh. The origin of these impurities may be traced back to exemplary elements and compounds found in exemplary consumable precursors. A minor percentage of impurity may be unavoidable in such materials but does not pose significant issues for industrial applications.

[0039] The Loss on Ignition (L.O.I) percentage in XRF analysis may represent the proportion of volatile substances in an exemplary sample. An exemplary XRF analysis procedure may involve heating exemplary samples at about 950 °C (in a furnace) for one hour after weighing them. Post-cooling, exemplary samples may be weighed again and any weight difference may be calculated as a percentage representing volatile substances or L.O.I. In spite that an exemplary XRF analysis method may have its limitations — it may struggle with accurate measurement of elements with an atomic number less than 11. Given this limitation and considering that carbon (atomic number 6) and oxygen of calcium carbonate may not be accurately measured using XRF, a temperature of about 950 °C may be utilized to eliminate these elements as volatile substances. Consequently, about 44.4% of exemplary synthesizedcalcium carbonate may show up as volatile substances which may be attributed to carbon present in carbonate released as CO2 gas at about 950 °C.

[0040] It's noteworthy that primary purpose of an exemplary method similar to method 100 may be synthesizing nano-calcium carbonate in calcite phase. However, by modifying both concentration and type of precursors and surfactant, it may be possible to synthesize other phases, such as aragonite alongside calcite. In an exemplary embodiment, an exemplary mixture of calcite and aragonite nanoparticles was prepared by simultaneously adding solutions of calcium chloride (0.1 M) and sodium carbonate (0.1 M) in a 1:1 ratio over an hour to deionized water maintained at a temperature of about 50 °C. An exemplary mixture contained 0.05% PVP as a surfactant, was stirred at a speed of about 1200 rpm, and maintained at a working pH range of about 11-12. FIG. 4 illustrates plot 400 of XRD pattern analysis of exemplary calcium carbonate nanoparticles revealing an exemplary composition comprising a mixture of aragonite and calcite phases, consistent with one or more exemplary embodiments of the present disclosure.

[0041] Morphology and dimensions of exemplary calcium carbonate nanoparticles were examined using TEM analysis. FIG. 5 illustrates TEM images 500 of exemplary calcium carbonate nanoparticles, consistent with one or more exemplary embodiments of the present disclosure. The precise size of exemplary calcium carbonate nanoparticles was further determined via an exemplary image analysis software, yielding an average particle size of less than 100 nanometers. High-speed stirring and pronounced turbulence were employed during solution mixing (using a magnetic stirrer) in an exemplary synthesis process to regulate particle size and inhibit sprout growth. Furthermore, inflow rate of sodium carbonate solution to calcium chloride solution was meticulously calculated to ensure that an exemplary reaction between precursors may span for about three hours at a constant rotation speed of about 1200rpm, thus facilitating complete process execution. Furthermore, EDTA surfactant was utilized to regulate the size of exemplary particles and inhibit development of calcite phase. EDTA, by inducing alterations on the surface of germinated nanoparticles in solution, may restrict their growth through creating separation between germinated solid particles and establishing a surface charge. Meanwhile, EDTA may generate repulsion between exemplary germinated solid particles via electrostatic force, thereby preventing particle adhesion and growth.

[0042] Moreover, incorporation of PAA polymer surfactant not only aids in controlling calcite nanoparticle size but also may facilitate formation of spherical and quasi-spherical shaped particles. It is also noteworthy that during synthesis, reactor speed may be maintained at about 1200 rpm in accordance with the input flow rate of sodium carbonate solution into calcium chloride solution at point of entry. Maintaining reactor speed at about 12000 rpm may prevent localized sprouting and may avoid bud agglomeration, thus inhibiting their growth.

[0043] While the foregoing has described what are considered to be the best mode and / or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.

[0044] Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.

[0045] The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of Sections 101, 102, or 103 of the Patent Act, nor should they be interpreted in such a way. Any unintended embracement of such subject matter is hereby disclaimed.

[0046] Except as stated immediately above, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is or is not recited in the claims.

[0047] It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. An element proceeded by “a” or “an” does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0048] Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.

[0049] It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study, except where specific meanings have otherwise been set forth herein. Relational terms such as “first” and “second” and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0050] The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it may be seen that various features are grouped together in various implementations. This is for purposes of streamlining the disclosure, and is not to be interpreted as reflecting an intention that the claimed implementations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed implementation. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.While various implementations have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more implementations and implementations are possible that are within the scope of the implementations. Although many possible combinations of features are shown in the accompanying figures and discussed in this detailed description, many other combinations of the disclosed features are possible. Any feature of any implementation may be used in combination with or substituted for any other feature or element in any other implementation unless specifically restricted. Therefore, it will be understood that any of the features shownand / or discussed in the present disclosure may be implemented together in any suitable combination. Accordingly, the implementations are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.

Claims

What is claimed is:

1. A method for synthesizing calcium carbonate nanoparticles, comprising: forming a calcium chloride solution by dissolving calcium chloride in water with a concentration of 0.5 M, wherein the calcium chloride has a purity between 99% (w / w) and 99.9% (w / w); forming a mixture by adding polyacrylic acid (PAA) and ethylenediaminetetraacetic acid (EDTA) with a weight ratio (PAA:EDTA) of 1:1 to the calcium chloride solution, wherein the calcium carbonate nanoparticles comprise PAA with a concentration of 0.5% (w / w) and EDTA with a concentration of 0.5% (w / w); forming a sodium carbonate solution by dissolving sodium carbonate in water with a concentration of 0.5 M, wherein the sodium carbonate has a purity between 98% (w / w) and 99.9% (w / w); forming a calcium carbonate suspension comprising: forming a reaction mixture with a pH level of 8.5-9 by adding the sodium carbonate solution, with a volume flow rate between 1 L / min and 5 L / min, to the mixture; and mixing the reaction mixture with a rotation speed between 1200 rpm and 1500 rpm for a time duration between 90 minutes and 120 minutes; forming a calcium carbonate slurry by filtering the calcium carbonate suspension through a rotating silicon carbide (SiC) filter with a pore size between 50 nm and 150 nm;forming calcium carbonate aggregates by drying the calcium carbonate slurry in a rotary dryer with a temperature level between 100 °C and 120 °C for a time duration between 100 minutes and 120 minutes; forming a first grinded calcium carbonate particles by grinding the calcium carbonate aggregates using a pin mill; forming a second grinded calcium carbonate particles by grinding the first grinded calcium carbonate particles using a ball mill; and forming the calcium carbonate nanoparticles with an average particle size between 20 nm and 150 nm by grinding the second grinded calcium carbonate particles using a jet mill.

2. A method for synthesizing calcium carbonate nanoparticles, comprising: forming a calcium chloride solution by dissolving calcium chloride in water with a concentration between 0.1 M and 0.5 M; forming a mixture by adding polyacrylic acid (PAA) and ethylenediaminetetraacetic acid (EDTA) with a weight ratio (PAA:EDTA) of 1:1 to the calcium chloride solution, wherein the calcium carbonate nanoparticles comprise PAA with a concentration between 0.1% (w / w) and 0.5% (w / w) and EDTA with a concentration between 0.1% (w / w) and 0.5% (w / w); forming a sodium carbonate solution by dissolving sodium carbonate in water with a concentration between 0.1 M and 0.5 M; forming a calcium carbonate suspension comprising forming a reaction mixture by adding the sodium carbonate solution to the mixture; forming a calcium carbonate slurry by filtering the calcium carbonate suspension through a filter with a pore size between 50 nm and 150 nm;forming calcium carbonate aggregates by drying the calcium carbonate slurry at a temperature level between 100 °C and 120 °C; forming a first grinded calcium carbonate particles by grinding the calcium carbonate aggregates using a pin mill; forming a second grinded calcium carbonate particles by grinding the first grinded calcium carbonate particles using a ball mill; and forming the calcium carbonate nanoparticles by grinding the second grinded calcium carbonate particles using a jet mill.

3. The method of claim 2, wherein forming the calcium carbonate nanoparticles by grinding the second grinded calcium carbonate particles using the jet mill comprises forming the calcium carbonate nanoparticles with an average particle size between 20 nm and 150 nm by grinding the second grinded calcium carbonate particles using the jet mill.

4. The method of claim 2, wherein dissolving the calcium chloride in water with the concentration between 0.1 M and 0.5 M comprises dissolving the calcium chloride, with a purity of 99-99.9% (w / w), in water with a concentration of 0.5 M.

5. The method of claim 2, wherein the calcium carbonate nanoparticles comprise PAA with a concentration of 0.5% (w / w) and EDTA with a concentration of 0.5% (w / w).

6. The method of claim 2, wherein dissolving the sodium carbonate in water with the concentration between 0.1 M and 0.5 M comprises dissolving the sodium carbonate, with a purity of 98-99.9% (w / w), in water with a concentration of 0.5 M.

7. The method of claim 2, wherein forming the calcium carbonate suspension comprising forming the reaction mixture by adding the sodium carbonate solution to the mixture comprises:forming a reaction mixture with a pH level of 8.5-9 by adding the sodium carbonate solution, with a volume flow rate between 1 L / min and 5 L / min, to the mixture; and mixing the reaction mixture with a rotation speed between 1200 rpm and 1500 rpm for a time duration between 90 minutes and 120 minutes.

8. The method of claim 2, wherein filtering the calcium carbonate suspension through the filter with the pore size between 50 nm and 150 nm comprises filtering the calcium carbonate suspension through a rotating silicon carbide (SiC) filter with the pore size between 50 nm and 150 nm and a rotation speed between 2 rpm and 3 rpm.

9. The method of claim 2, wherein drying the calcium carbonate slurry at the temperature level between 100 °C and 120 °C comprises drying the calcium carbonate slurry in a rotary dryer with the temperature level between 100 °C and 120 °C for a time duration between 100 minutes and120 minutes.

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