WO2015072609A1 - Three-dimensional measuring method for porous geopolymer using electronic tomography - Google Patents

Three-dimensional measuring method for porous geopolymer using electronic tomography Download PDF

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WO2015072609A1
WO2015072609A1 PCT/KR2013/010614 KR2013010614W WO2015072609A1 WO 2015072609 A1 WO2015072609 A1 WO 2015072609A1 KR 2013010614 W KR2013010614 W KR 2013010614W WO 2015072609 A1 WO2015072609 A1 WO 2015072609A1
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geopolymer
dimensionally
porous
milling
coal ash
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French (fr)
Korean (ko)
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이수정
전철민
강남희
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한국지질자원연구원
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B15/00—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons
    • G01B15/04—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons for measuring contours or curvatures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B15/00—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons
    • G01B15/04—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons for measuring contours or curvatures
    • G01B15/045—Measuring arrangements characterised by the use of electromagnetic waves or particle radiation, e.g. by the use of microwaves, X-rays, gamma rays or electrons for measuring contours or curvatures by measuring absorption
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K15/00—Electron-beam welding or cutting
    • B23K15/08—Removing material, e.g. by cutting, by hole drilling
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/04—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material
    • G01N23/046—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material using tomography, e.g. computed tomography [CT]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
    • G01N23/225—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material using electron or ion
    • G01N23/2251—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material using electron or ion using incident electron beams, e.g. scanning electron microscopy [SEM]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P40/00—Technologies relating to the processing of minerals
    • Y02P40/10—Production of cement, e.g. improving or optimising the production methods; Cement grinding

Definitions

  • the present invention relates to a method for three-dimensionally measuring porous geopolymers using electron tomography.
  • the geopolymer is a kind of an alkali active binder prepared by chemical reaction of a silicate aluminum raw material with an alkali active solution at a low temperature.
  • Pozzolans including fly ash, meta kaolin, and natural pozzolans, are used as raw materials to produce geopolymers. Silicon and aluminum as raw materials are dissolved in an alkaline solution and the three-dimensional network structure is cured later, but the mechanism of the geopolymerization reaction has not yet been fully elucidated.
  • Geopolymers have advantages such as corrosion resistance, fire resistance, compressive and tensile strength, and fast strength strength compared to general Portland cement (OPC), and with these advantages they greatly reduce CO 2 emissions ,
  • a geopolymer is one of the potential alternatives to OPC.
  • long-term durability problems remain an obstacle to commercializing geopolymer cements for construction.
  • OPC much research has been done on the microstructure, pore structure and interface between aggregate and cement binder, and pore volume, pore size distribution, and pore connectivity have many properties of binder materials such as permeability, shrinkage, .
  • the long term durability is directly affected by the porosity of the geopolymer and OPC.
  • the microstructure including pore volume, porosity and pore distribution around the gel framework, determines the mechanical properties of the geopolymer. Penetration of chemicals such as chlorides into the pores of the geopolymer degrades the quality of the geopolymer concrete, so pore structure identification and quantification within the geopolymer is an important factor in understanding the impact on the durability of the geopolymer.
  • the present invention provides a method for manufacturing a geomolecule comprising the steps of: milling a geopolymer with an ion beam to prepare a geopolymer having a plate-like structure; Continuously obliquely observing the prepared sheet-like geopolymer with a transmission electron microscope and photographing with a CCD camera (charge-coupled device camera); And reconstructing the photographed image three-dimensionally using filtered back-projection.
  • the present invention also provides a three-dimensional measurement method of a porous geopolymer using electron tomography.
  • the geopolymer is produced by collecting coal ash from an embedding circuit, crushing and pulverizing the mixture and mixing with an activator.
  • the size of the pulverized and finely pulverized coal ash is 100-200 ⁇ .
  • the method may further include removing unburnt carbon contained in the coal ash after the wet milling.
  • the activator is characterized by comprising sodium silicate and sodium hydroxide.
  • the three-dimensional measurement method of the porous geopolymer is characterized by analyzing nano-sized pores contained in the porous geopolymer.
  • the geopolymer is characterized in that the molar ratio of Si: Al is 1.5 - 2.8 and the molar ratio of Na: Al is 1.2 - 1.5.
  • the present invention also relates to a method for producing a geopolymer comprising the steps of: milling a geopolymer with an ion beam to prepare a geopolymer having a plate-like structure; Immersing the prepared flaky geopolymer in a gold colloid solution and then drying to apply gold particles; Continuously obliquely scanning the sheet-like geopolymer coated with the gold particles, observing the particles with a transmission electron microscope, and photographing the particles with a charge-coupled device camera; And reconstructing the photographed image three-dimensionally using filtered back-projection.
  • the present invention also provides a three-dimensional measurement method of a porous geopolymer using electron tomography.
  • the present invention it is possible to analyze the pore characteristics of a geopolymer by nondestructive analysis at the nanometer level, obtain an image by continuously tilting the geopolymer to an elevation angle, and then reconstruct the three- ), It is possible to accurately obtain the pore shape and the pore distribution information in the geopolymer that can not be obtained by X-ray tomography.
  • the durability of the geopolymer can be accurately predicted by quantitatively evaluating the pores of the nano-scale level present in the geopolymer.
  • FIG. 1 is a flowchart showing a three-dimensional measurement method of a porous geopolymer using an electron tomography according to the present invention.
  • FIG. 2 is a photograph showing a buried structure and a bottom material, and is a backscattered electron image of iron oxide.
  • Figure 3 is a TEM bright field of a thin sheet geopolymer.
  • FIG. 4 is a photograph showing two z-slice images at intervals of 10.7 nm.
  • Figure 5 is a graph showing the pore size distribution of each of the circles in the four z-slices.
  • FIG. 6 is a photograph of a three-dimensional rendering of a reconstructed tomographic photograph of a sheet-form geopolymer.
  • the present invention relates to a method for producing a geopolymer comprising the steps of: milling a geopolymer with an ion beam to prepare a geopolymer having a plate-like structure;
  • the present invention also provides a method for three-dimensionally measuring a porous geopolymer using electron tomography.
  • the three dimensional measurement method of the porous geopolymer using the electron tomography according to the present invention has an effect on the transmittance, shrinkage, elastic modulus and strength of the material, and the pore volume, pore size distribution and pore connectivity Can be accurately measured.
  • the pore structure of the porous geopolymer can be accurately analyzed.
  • it is possible to accurately analyze the pore structure of the geopolymer by recognizing the problem that a clear image can not be obtained due to the low resolution of the conventional X-ray tomography and reconstructing it in three dimensions by using electron tomography and back projection, Durability can be accurately predicted.
  • FIG. 1 is a flowchart showing a three-dimensional measurement method of a porous geopolymer using an electron tomography according to the present invention.
  • the present invention will be described in detail with reference to Fig.
  • the method for three-dimensionally measuring a porous geopolymer using electron tomography includes a step (SlOO) of producing a geopolymer having a plate-like structure by milling a geopolymer with an ion beam.
  • the geopolymer may be prepared by collecting coal ash from an embedding circuit, crushing it, and pulverizing it, mixing it with an activator, wet milling using the rod mill after the pulverization and pulverization, and after the wet milling, And removing the contained unburned carbon by float sorting.
  • the size of the pulverized and finely pulverized coal material is preferably 100 to 200 ⁇ passing through 65 mesh, and float sorting can be easily performed due to the size of the pulverized and pulverized coal material.
  • the size of the crushed and pulverized coal ash is less than 100 ⁇ , it may be difficult to isolate individual particles by floating.
  • the particle size exceeds 200 ⁇ , unburnt carbon and fly ash particles are not separated, .
  • the float sorting may include a roughing step and a scavenging step.
  • the coal ash is washed, dehydrated and dried in an oven to be used as a raw material for the production of a geopolymer.
  • the activator may be added to the coal ash for the production of the geopolymer produced by the above method, mixed with the cement mixer, and cured to prepare the geopolymer.
  • the activator comprises sodium silicate and sodium hydroxide, and the molar ratio of Si: Al and the molar ratio of Na: Al in the geopolymer are 1.5-2.8 and 1.2-1.5, respectively.
  • Poly (sialate siloxo)) can be prepared by setting the mole ratio of Si: Al to 1.5-2.8.
  • the molar ratio of Na: Al is 1.2-1.5 because Na is volatile, (efflorescence) phenomenon can be prevented.
  • the prepared geopolymer is produced as a geopolymer having a plate-like structure by focused ion beam milling and can be milled after cutting with gallium ions to minimize milling defects.
  • the method for three-dimensionally measuring a porous geopolymer using the electron tomography comprises the steps of continuously obliquely observing the prepared sheet-like geopolymer with a transmission electron microscope, and then photographing with a CCD-camera (charge-coupled device camera) ).
  • CCD-camera charge-coupled device camera
  • the prepared sheet-like geopolymers can be continuously photographed at -55 ° to + 55 ° at intervals of 1 °, observed with a transmission electron microscope (TEM), and then photographed using a CCD camera.
  • the transmission electron microscope can obtain a bright field image by observing the plate-shaped geopolymer with an energy of 120 keV, and photographs the obtained image with a CCD camera.
  • the method for three-dimensional measurement of porous geopolymers using electron tomography includes reconstructing the photographed photographs three-dimensionally using filtered back-projection (S120).
  • the photographed photographs are reconstructed in three dimensions using a filter back projection method.
  • the reconstructed tomographic photographs can be analyzed using Chimera software v.16 and IMOD v.4.1.10.
  • the three dimensional measurement method of the porous geopolymer can analyze nano-sized pores contained in the porous geopolymer.
  • the present invention also relates to a method for producing a geopolymer comprising the steps of: milling a geopolymer with an ion beam to prepare a geopolymer having a plate-like structure;
  • the present invention also provides a method for three-dimensionally measuring a porous geopolymer using electron tomography.
  • the size of the gold particles applied to the flaky geopolymer is preferably 10 nm and can be used as an index for precise alignment according to an angle change.
  • Example 1 Three-dimensional measurement of a porous geopolymer
  • the geopolymer samples were pond ash, a bottom ash mixed with a small amount of rejected fly ash from Samchunpo Thermal Power Plant.
  • the flooring is coarse, porous coal particles, brownish gray. The remainder is a thick part of fly ash that is abandoned in landfills because of its high unburned carbon content and large particle size (> 45 ⁇ m).
  • Ash (ash) was collected in a landfill and dried at room temperature for 3 days. Thereafter, the 65 mesh (212 ⁇ ) was pulverized and pulverized to have a powder throughput of 43%.
  • 500 g of pulverized coal ash was slurried in 500 mL of water and wet milled to a size of less than 212 ⁇ m using a rod mill.
  • the unburned carbon content was measured by proximate analysis and the unburned carbon was removed by froth flotation because it interfered with the geopolymerization reaction.
  • About 60 g / t of kerosene and 20 g / t of fine oil were selectively absorbed on the surface of the particles, and the bonded carbon particles were frosted so as not to be lost.
  • a dispersant (Na 2 SiO 3 ) of about 600 g / t was used to minimize heterogeneous aggregation and promote selectivity.
  • Flotation screening consists of the first stage of roughing and the second stage of scavenging. Flocculant After washing, the washed coal ash was dehydrated and dried in an oven for one day to be used as a raw material for producing a geopolymer. The amount of carbon in the washed coal ash was measured by industrial analysis.
  • Platelet-shaped geopolymers were prepared from focused ion beam milling (Quanta 3D FEG, FEI) from the areas identified as geopolymer gels and not reacting with the coal precursor. Cutting with gallium ions at 30 keV and 15 nA, then polishing at 5 keV and 48 pA minimized milling defects.
  • the gold colloid solution was diluted 10 times with distilled water and 10 nm gold particles were applied to the upper and lower surfaces of the sample and used as indexes for precise alignment of angle changes. To place the gold particles on the specimen, the platelet-shaped geopolymer was immersed in a diluted gold colloid solution for 1 minute and then dried to place the gold particles on both surfaces of the specimen.
  • TEM images were obtained using FEI TECNAI G 2 Spirit equipped with a large inclination holder and a 2048 ⁇ 2048 pixel CCD camera.
  • the bright field image (acceleration of 120 keV) along the angle of the plate geometry was obtained from -55 ° to + 55 ° at an angle of 1 ° inclination.
  • Filter back-projection which is used for three-dimensional reconstruction of the TEM image, was used.
  • Each image size reduced the image size in half by an average pixel of 1024 pixels by 1024 pixels to minimize computer computation time.
  • Reconstructed tomographic images were analyzed using Chimera software v.16 and IMOD v.4.1.10.
  • the chemical composition and phase of the carbonaceous material were analyzed in the three dimensional measurement method of the porous geopolymer using the electron tomography according to the present invention.
  • the collected buried sludge showed various sizes and shapes (see Fig. 2 (a)).
  • the bottom material was porous with a large particle size, sandy and grayish gray (see Fig. 2 (b)).
  • Most of the coal particles were on aluminum silicate with small amounts of iron, calcium, potassium, magnesium and sodium (cf. Fig. 2).
  • Table 1 below shows the results of XRF analysis of the chemical composition of the landfill with unburned carbon removed.
  • the landfill was composed mainly of 57.7% of SiO 2 , 22.6% of Al 2 O 3 and 9.70% of Fe 2 O 3 , and contained only 4.13% of CaO.
  • the residual carbon content was 4.69%. No carbon was found in the coal ash after removal of unburned carbon.
  • the main crystal phases of coal ash were quartz, 16.1 wt%, mullite, 15.5 wt%, albite, 7.4 wt% and hematite, 1.5 wt%
  • the amorphous portion was 59.5 wt% and the composition of the amorphous portion was calculated as the difference between the bulk chemical composition and the crystalline constituents as oxide.
  • Table 2 below shows the chemical composition of the amorphous portion of the landfill.
  • the Si: Al ratio of coal ash removed unburned carbon was determined to be 1.30. Silicon and sodium were added to the coal ash so that the molar ratio of Si / Al was 2.0 and the molar ratio of Na / Al was 1.2.
  • the mixing ratio of the geopolymer gel was 61.5 wt% of coal ash, 24.3 wt% of silicate solution, 4.2 wt% of NaOH and 10 wt% of distilled water.
  • the porosity of the geopolymer prepared by the three-dimensional measurement method of the porous geopolymer using the electron tomography according to the present invention was analyzed.
  • Figure 4 is a TEM light field of a sheet-form geopolymer.
  • the pore structure of the flaky geopolymer was apparent due to the high contrast difference between the paste and the pores. Due to bragg scattering contrast at successive angular changes, dark spherical gold particles and numerous small crystals Were identified.
  • the crystalline phase was present in the geopolymer even though the gel phase was amorphous.
  • the crystal phase was generally larger, darker, and asymmetric than gold particles.
  • the diffuse diffraction ring generated from the gold particles was found in the electron diffraction analysis and no diffraction spot or ring appeared on the crystal.
  • the distinctive shape or ring in the diffraction pattern reflects the degree of long-range regularity.
  • the crystalline phase is judged to be a low-order zeolite based on energy scattering X-ray spectroscopic data. It is judged that zeolite is formed to some extent in the zeolite reaction.
  • Figure 5 is a photograph showing two z-slice images spaced apart by about 10.7 nm. The outer diameters of some pores are shown in Figs. 4 (a) and 4 (b). Most of the pores were almost circular or elliptical, but some were somewhat amorphous in shape.
  • FIG. 6 is a graph showing the pore size distribution of each of the circles in the four z-slices.
  • the diameters of the outer diameters of 145 pores in the four z-slices ranged from 13.5 to 147 nm.
  • the number of pores was about 20 to 60 nm, the number of pores out of the range was 8, and the pores having long and narrow pores (the part circled in FIG. 4 (b)) were 80 nm or more.
  • Multiple pores are present in two or more slices with a slice spacing of 10.7 nm. Thus, this size range does not represent 145 pore diameters, but provides an approximation of the size of the pores.
  • the porosity in the geopolymer was segmented and reconstructed into three dimensions as shown in Fig.
  • the segmentation is a process of grouping pixels based on different contrast values to distinguish between different images. For example, pores are distinguished by large contrast differences from the gel in the geopolymer.
  • manual sorting which manually distinguishes between contrasts without using an automated program, can be time-consuming and subjective. Quantification based on classification by thresholding can quickly distinguish images from other images.
  • the present invention quantifies pores by manual sorting because the binarization may not be able to completely separate pores and gels in z-slices.
  • the process of immersing the sheet-like geopolymer in a diluted gold colloid solution and then drying will cause the sheet-form geopolymer to bend slowly and reduce the volume of interest for quantifying the porosity.
  • the width, length, and thickness of the sheet-form geopolymers selected for sorting were 482 nm, 482 nm, and 32.2 nm, respectively, and the volume was 0.00748 mu m, which is a value of 19.3 It is a value corresponding to%.
  • the porosity in this region was 7.15%. This value is much lower than the 30.5% and 23 ⁇ 28% measured by the conventional method.
  • Electron tomography analyzes pore structures for very small volumes at the nanometer level at higher resolutions than mercury porosimetry (MIP), metal infiltration and X-ray tomography methods used for larger objects of several tens of millimeters or more. can do. Large pores of several hundred nanometers or more coexist with sizes ranging from microns to less than 5 nm, and pore sizes range from 100 nm to 10 nm. As shown in FIG. 6, the presence of micropores can be observed directly by visual observation.
  • MIP mercury porosimetry
  • the artifacts in the reconstructed image have a wormhole structure much smaller than the pores and arise from the scattering noise of the zeolite crystals present in the plate geometry polymer.
  • Typical algorithms for reconstruction in bright field electron tomography are filtered back projection (FBP) and simultaneous iterative reconstruction technique (SIRT). These algorithms are based on three-dimensional Performing reconfiguration always causes defects.
  • the spatial distribution of the dark portions in the crystal can be offset by the reconstruction of the entire sequential angle change. Therefore, it is considered that the wormhole structure is formed due to the effect of lightness error caused by bragg scattering and the uneven chemical composition in the solid phase region.
  • the pore size data is reliable.
  • FIG. 7 is a photograph of a three-dimensional rendering of a reconstructed tomographic photograph of a sheet-form geopolymer.
  • FIG. 7 most of the pores are not connected, and some large pores appear to be formed by a combination of a plurality of adjacent small pores.
  • the irregular structure of the pores in a 3-D tomographic image appears to be consistent with that observed in the z-slice image.
  • the electron tomography of the dark night scanning transmission electron microscope (ADF-STEM) is considered to be more appropriate for studying the geopolymer, but has a disadvantage in that it has a low resolution of less than 1/5 of the bright field mode. Pores smaller than those identified in the present invention can be identified by high magnification electron tomography.
  • the missing wedge effect is caused by the inclination angle limit up to + 70 °, and defects occur due to the reduction in projection in three-dimensional reconstruction.
  • the porosity changes when the sample to be measured is tilted to more than ⁇ 90 °, and the sewing wedge effect can be completely eliminated.
  • the porosity obtained in the present invention is a three-dimensional quantitative evaluation of micropores in a geopolymer gel, and provides a method for more specifically understanding the pore structure of a geopolymer at a spatial resolution on the order of nanometers.
  • One way is not to completely characterize the pore size range in the sample, but the method of the present invention is based on the use of TEM and filter corrected back-projection electron tomography in which nanopores at nanometer resolution Dimensional pore network and pore connectivity.
  • the present invention is not limited to the three-dimensional measurement method of the porous geopolymer using the electron tomography according to the present invention, but various modifications may be made without departing from the scope of the present invention.

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Abstract

The present invention relates to a three-dimensional measuring method for a porous geopolymer using electronic tomography, and more specifically relates to a three-dimensional measuring method for a porous geopolymer using electronic tomography, the method comprising the steps of: manufacturing a geopolymer of plate-shaped structure by milling a geopolymer with an ion beam; observing the manufactured plate-shaped geopolymer with a transmission electron microscope while tilting the geopolymer continuously, and then photographing the geopolymer with a charge-coupled device camera (CCD camera); and three-dimensionally reconstructing the photographed picture by using filtered back projection.

Description

전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법Three dimensional measurement method of porous geopolymer using electron tomography
본 발명은 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법에 관한 것이다. The present invention relates to a method for three-dimensionally measuring porous geopolymers using electron tomography.
지오폴리머는 규산 알루미늄 원료 물질을 저온에서 알칼리 활성 용액으로 화학 반응시켜 제조되는 알칼리 활성 결합재의 한 종류이다. 비산재, 메타카올린 및 천연 포졸란을 포함하는 포졸란 물질은 지오폴리머를 생산하기 위한 원료물질로 사용된다. 원료물질로서 실리콘과 알루미늄은 알칼리성 용액에서 용해되고, 3차원 네트워크 구조는 후에 경화되지만, 지오폴리머화 반응 메커니즘은 아직 완전히 규명되지 않았다.The geopolymer is a kind of an alkali active binder prepared by chemical reaction of a silicate aluminum raw material with an alkali active solution at a low temperature. Pozzolans, including fly ash, meta kaolin, and natural pozzolans, are used as raw materials to produce geopolymers. Silicon and aluminum as raw materials are dissolved in an alkaline solution and the three-dimensional network structure is cured later, but the mechanism of the geopolymerization reaction has not yet been fully elucidated.
지오폴리머는 일반적인 포트란드 시멘트(OPC)와 비교하여 내식성(corrosion resistance), 내화성, 압축 및 인장 강도, 빠른 강도 발현(strength gain)과 같은 이점이 있고, 이러한 장점과 함께 CO2 방출을 크게 감소시키므로, 지오폴리머가 OPC에 대한 잠재적인 대안 중 하나이다. 그러나, 건설용 지오폴리머 시멘트를 상업화하기에는 장시간 내구성에 대한 문제가 장애물로 남아있다. OPC의 경우, 골재와 시멘트 결합재 사이의 미세구조, 기공 구조 및 경계면에 대한 많은 연구가 수행되었고, 기공 부피, 기공 크기 분포 및 기공 연결성은 투과성, 수축율, 탄성도 및 강도와 같은 결합재 물질의 많은 특성에 영향을 미친다. 또한, 장시간 내구성은 지오폴리머와 OPC의 공극율에 직접적으로 영향을 받는다. 겔 프레임워크(framework) 주위의 기공 부피, 공극율 및 기공 분포를 포함하는 미세구조는 지오폴리머의 기계적 특성을 결정한다. 지오폴리머의 기공에 염화물과 같은 화학물질의 침투는 지오폴리머 콘크리트의 품질을 저하시키므로, 지오폴리머 내의 기공 구조 특정화 및 정량화는 지오폴리머의 내구성에 대한 영향을 이해하는데 중요한 요소이다.Geopolymers have advantages such as corrosion resistance, fire resistance, compressive and tensile strength, and fast strength strength compared to general Portland cement (OPC), and with these advantages they greatly reduce CO 2 emissions , A geopolymer is one of the potential alternatives to OPC. However, long-term durability problems remain an obstacle to commercializing geopolymer cements for construction. In the case of OPC, much research has been done on the microstructure, pore structure and interface between aggregate and cement binder, and pore volume, pore size distribution, and pore connectivity have many properties of binder materials such as permeability, shrinkage, . Also, the long term durability is directly affected by the porosity of the geopolymer and OPC. The microstructure, including pore volume, porosity and pore distribution around the gel framework, determines the mechanical properties of the geopolymer. Penetration of chemicals such as chlorides into the pores of the geopolymer degrades the quality of the geopolymer concrete, so pore structure identification and quantification within the geopolymer is an important factor in understanding the impact on the durability of the geopolymer.
가스 흡착 및 수은압입법(MIP)은 기포 크기 분포를 결정하기 위해 널리 사용되어왔다. 그러나, 상기 방법으로 데이터를 이해하기 위해서는 물질 내에서 기공이 규칙적인 구조를 가지고 서로 연결되어 있다는 가정이 필요하다. 시멘트와 콘크리트에 대한 수은압입법은 기공 크기가 SEM 이미지로 얻어진 크기보다 세배 정도 낮을 수 있다는 문제가 있다. 또한, 지오폴리머 내에서의 몇몇 보이드(void)는 후방산란전자(back-scattered electron)에서 겔에 의해 연결되지 않은 것으로 나타난다. X-선 마이크로 단층촬영은 포틀란드 시멘트 제품에서 기공 크기 분포에 대한 정보를 얻는데 사용되고 있고, 지오폴리머의 기공 구조의 평가에도 사용되고 있지만, 제한된 해상도로 인해 뚜렷한 3차원 이미지의 미세 기공 구조에 대한 정보를 제공하지 못하는 문제가 있다. Gas adsorption and mercury intrusion (MIP) have been widely used to determine the bubble size distribution. However, in order to understand the data by the above method, it is necessary to assume that the pores are connected to each other with a regular structure in the material. The mercury intrusion method for cement and concrete has a problem that the pore size may be three times lower than the size obtained by the SEM image. Also, some voids in the geopolymer appear to be not connected by gels in back-scattered electrons. X-ray micro-tomography is used to obtain information on the pore size distribution in Portland cement products, and is also used to evaluate the pore structure of geopolymers, but due to the limited resolution, information on the microporous structure of distinct three- There is a problem that can not be provided.
따라서, 본 발명은 다공성 지오폴리머 내의 기공 구조, 기공 분포 및 크기를 정확하게 분석할 수 있는 전자 단층촬영을 이용하여 다공성 지오폴리머에 포함된 미세 기공을 3차원으로 측정하는 방법을 제공하는데 있다. Accordingly, it is an object of the present invention to provide a method for three-dimensionally measuring micropores contained in a porous geopolymer by using an electron tomography capable of accurately analyzing pore structure, pore distribution and size within the porous geopolymer.
본 발명이 해결하고자 하는 과제는 이상에서 언급한 과제(들)로 제한되지 않으며, 언급되지 않은 또 다른 과제(들)는 이하의 기재로부터 당업자에게 명확하게 이해될 수 있을 것이다.The problems to be solved by the present invention are not limited to the above-mentioned problem (s), and another problem (s) not mentioned can be understood by those skilled in the art from the following description.
상기 과제를 해결하기 위해, 본 발명은 지오폴리머를 이온빔으로 밀링하여 판상 구조의 지오폴리머를 제조하는 단계; 상기 제조된 판상 지오폴리머를 연속적으로 기울여 투과전자현미경으로 관찰한 후 CCD 카메라(charge-coupled device camera)로 촬영하는 단계; 및 상기 촬영된 사진을 필터보정 역투영법(filtered back-projection)을 이용하여 3차원으로 재구성하는 단계;를 포함하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법을 제공한다.In order to solve the above-mentioned problems, the present invention provides a method for manufacturing a geomolecule comprising the steps of: milling a geopolymer with an ion beam to prepare a geopolymer having a plate-like structure; Continuously obliquely observing the prepared sheet-like geopolymer with a transmission electron microscope and photographing with a CCD camera (charge-coupled device camera); And reconstructing the photographed image three-dimensionally using filtered back-projection. The present invention also provides a three-dimensional measurement method of a porous geopolymer using electron tomography.
상기 지오폴리머는 매립회로부터 석탄재를 수집한 후 파쇄 및 미분쇄하고 활성화제와 혼합하여 제조되는 것을 특징으로 한다. The geopolymer is produced by collecting coal ash from an embedding circuit, crushing and pulverizing the mixture and mixing with an activator.
상기 파쇄 및 미분쇄된 석탄재의 크기는 100 - 200 ㎛인 것을 특징으로 한다. The size of the pulverized and finely pulverized coal ash is 100-200 탆.
상기 파쇄 및 미분쇄 공정 후 로드 밀을 이용하여 습식 밀링하는 단계를 더 포함할 수 있다. And wet milling using the rod mill after the crushing and pulverizing process.
또한, 상기 습식 밀링 후 석탄재에 포함된 미연탄소를 부유 선별로 제거하는 단계를 더 포함할 수 있다. Further, the method may further include removing unburnt carbon contained in the coal ash after the wet milling.
상기 활성화제는 규산 나트륨 및 수산화나트륨을 포함하는 것을 특징으로 한다. The activator is characterized by comprising sodium silicate and sodium hydroxide.
상기 연속 기울임은 1°간격으로 -55°에서 +55°까지 수행되는 것을 특징으로 한다. And the continuous tilt is performed from -55 DEG to + 55 DEG at intervals of 1 DEG.
상기 다공성 지오폴리머의 3차원 측정방법은 다공성 지오폴리머에 포함된 나노 크기 기공을 분석하는 것을 특징으로 한다. The three-dimensional measurement method of the porous geopolymer is characterized by analyzing nano-sized pores contained in the porous geopolymer.
상기 지오폴리머는 Si:Al의 몰비가 1.5 - 2.8이고 Na:Al의 몰비가 1.2 - 1.5인 것을 특징으로 한다. The geopolymer is characterized in that the molar ratio of Si: Al is 1.5 - 2.8 and the molar ratio of Na: Al is 1.2 - 1.5.
또한, 본 발명은 지오폴리머를 이온빔으로 밀링하여 판상 구조의 지오폴리머를 제조하는 단계; 상기 제조된 판상 지오폴리머를 금 콜로이드 용액에 침지시킨 후 건조시켜 금 입자를 도포하는 단계; 상기 금 입자가 도포된 판상 지오폴리머를 연속적으로 기울여 투과전자현미경으로 관찰한 후 CCD 카메라(charge-coupled device camera)로 촬영하는 단계; 및 상기 촬영된 사진을 필터보정 역투영법(filtered back-projection)을 이용하여 3차원으로 재구성하는 단계;를 포함하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법을 제공한다.The present invention also relates to a method for producing a geopolymer comprising the steps of: milling a geopolymer with an ion beam to prepare a geopolymer having a plate-like structure; Immersing the prepared flaky geopolymer in a gold colloid solution and then drying to apply gold particles; Continuously obliquely scanning the sheet-like geopolymer coated with the gold particles, observing the particles with a transmission electron microscope, and photographing the particles with a charge-coupled device camera; And reconstructing the photographed image three-dimensionally using filtered back-projection. The present invention also provides a three-dimensional measurement method of a porous geopolymer using electron tomography.
본 발명에 따르면, 나노미터 수준에서 비파괴 분석으로 지오폴리머의 기공 특성들을 분석할 수 있고, 지오폴리머를 고각까지 연속적으로 기울이며 영상을 얻은 다음, 이 영상들을 3차원으로 재구성하는 전자 단층촬영(electron tomography)을 이용함으로써 X-선 단층촬영으로는 얻을 수 없는 기공 형상 및 지오폴리머 내의 기공 분포 정보를 정확하게 얻을 수 있다. According to the present invention, it is possible to analyze the pore characteristics of a geopolymer by nondestructive analysis at the nanometer level, obtain an image by continuously tilting the geopolymer to an elevation angle, and then reconstruct the three- ), It is possible to accurately obtain the pore shape and the pore distribution information in the geopolymer that can not be obtained by X-ray tomography.
또한, 지오폴리머 내에 존재하는 나노 크기 수준의 기공에 대한 정량적인 결과를 도출함으로써 지오폴리머의 내구성을 정확하게 예측할 수 있다.In addition, the durability of the geopolymer can be accurately predicted by quantitatively evaluating the pores of the nano-scale level present in the geopolymer.
도 1은 본 발명에 따른 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법을 나타낸 순서도이다.FIG. 1 is a flowchart showing a three-dimensional measurement method of a porous geopolymer using an electron tomography according to the present invention.
도 2는 매립회 및 바닥재를 나타낸 사진이고, 철산화물의 후방산란전자(backscattered electron) 이미지이다. 2 is a photograph showing a buried structure and a bottom material, and is a backscattered electron image of iron oxide.
도 3은 얇은 판상 지오폴리머의 TEM 명시 야상이다.Figure 3 is a TEM bright field of a thin sheet geopolymer.
도 4는 10.7 ㎚ 간격의 두개의 z-슬라이스 이미지를 나타낸 사진이다.4 is a photograph showing two z-slice images at intervals of 10.7 nm.
도 5는 4개의 z-슬라이스에서의 원으로 표시된 각각의 기공 크기 분포를 나타낸 그래프이다. Figure 5 is a graph showing the pore size distribution of each of the circles in the four z-slices.
도 6은 판상 지오폴리머의 재구성된 단층사진을 3차원으로 렌더링(rendering)한 사진이다.6 is a photograph of a three-dimensional rendering of a reconstructed tomographic photograph of a sheet-form geopolymer.
이하 첨부된 도면을 참조하면서 본 발명에 따른 바람직한 실시예를 상세히 설명하기로 한다.Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
본 발명의 이점 및 특징, 그리고 그것을 달성하는 방법은 첨부된 도면과 함께 상세하게 후술되어 있는 실시예들을 참조하면 명확해질 것이다.BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving it will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings.
그러나 본 발명은 이하에 개시되는 실시예들에 의해 한정되는 것이 아니라 서로 다른 다양한 형태로 구현될 것이며, 단지 본 실시예들은 본 발명의 개시가 완전하도록 하며, 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자에게 발명의 범주를 완전하게 알려주기 위해 제공되는 것이며, 본 발명은 청구항의 범주에 의해 정의될 뿐이다.The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.
또한, 본 발명을 설명함에 있어 관련된 공지 기술 등이 본 발명의 요지를 흐리게 할 수 있다고 판단되는 경우 그에 관한 자세한 설명은 생략하기로 한다.In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.
본 발명은 지오폴리머를 이온빔으로 밀링하여 판상 구조의 지오폴리머를 제조하는 단계;The present invention relates to a method for producing a geopolymer comprising the steps of: milling a geopolymer with an ion beam to prepare a geopolymer having a plate-like structure;
상기 제조된 판상 지오폴리머를 연속적으로 기울여 투과전자현미경으로 관찰한 후 CCD 카메라(charge-coupled device camera)로 촬영하는 단계; 및 Continuously obliquely observing the prepared sheet-like geopolymer with a transmission electron microscope and photographing with a CCD camera (charge-coupled device camera); And
상기 촬영된 사진을 필터보정 역투영법(filtered back-projection)을 이용하여 3차원으로 재구성하는 단계;를 포함하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법을 제공한다.And reconstructing the photographed image three-dimensionally using filtered back-projection. The present invention also provides a method for three-dimensionally measuring a porous geopolymer using electron tomography.
본 발명에 따른 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법은 재료의 투과율, 수축율, 탄성률 및 강도에 영향을 미치고 장기적으로 내구성을 좌우하는 재료 내 기공부피, 기공의 크기 분포 및 기공의 연결성을 정확하게 측정할 수 있으며, 특히 다공성 지오폴리머의 기공 구조를 정확하게 분석할 수 있다. 또한, 종래 X-선 단층촬영의 낮은 분해능 때문에 뚜렷한 영상을 얻지 못하는 문제점을 인지하고 이를 전자 단층촬영 및 역투영법을 이용하여 3차원으로 재구성함으로써 지오폴리머의 기공 구조를 정확하게 분석할 수 있어 지오폴리머의 내구성을 정확하게 예측할 수 있다. The three dimensional measurement method of the porous geopolymer using the electron tomography according to the present invention has an effect on the transmittance, shrinkage, elastic modulus and strength of the material, and the pore volume, pore size distribution and pore connectivity Can be accurately measured. In particular, the pore structure of the porous geopolymer can be accurately analyzed. In addition, it is possible to accurately analyze the pore structure of the geopolymer by recognizing the problem that a clear image can not be obtained due to the low resolution of the conventional X-ray tomography and reconstructing it in three dimensions by using electron tomography and back projection, Durability can be accurately predicted.
도 1은 본 발명에 따른 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법을 나타낸 순서도이다. 이하, 도 1을 참고하여 본 발명을 상세히 설명한다.FIG. 1 is a flowchart showing a three-dimensional measurement method of a porous geopolymer using an electron tomography according to the present invention. Hereinafter, the present invention will be described in detail with reference to Fig.
본 발명에 따른 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법은 지오폴리머를 이온빔으로 밀링하여 판상 구조의 지오폴리머를 제조하는 단계(S100)를 포함한다.The method for three-dimensionally measuring a porous geopolymer using electron tomography according to the present invention includes a step (SlOO) of producing a geopolymer having a plate-like structure by milling a geopolymer with an ion beam.
상기 지오폴리머는 매립회로부터 석탄재를 수집한 후 파쇄하고 미분쇄한 후 활성화제와 혼합하여 제조될 수 있고, 상기 파쇄 및 미분쇄 후 로드 밀을 이용하여 습식 밀링하는 단계 및 상기 습식 밀링 후 석탄재에 포함된 미연탄소를 부유 선별로 제거하는 단계를 더 포함할 수 있다. The geopolymer may be prepared by collecting coal ash from an embedding circuit, crushing it, and pulverizing it, mixing it with an activator, wet milling using the rod mill after the pulverization and pulverization, and after the wet milling, And removing the contained unburned carbon by float sorting.
상기 파쇄 및 미분쇄된 석탄재의 크기는 65 메쉬를 통과하는 100 - 200 ㎛인 것이 바람직하고, 상기 범위의 크기로 인해 부유 선별을 용이하게 수행할 수 있다. 상기 파쇄 및 미분쇄된 석탄재의 크기가 100 ㎛ 미만인 경우에는 부유 선별시 개체 분리가 용이하지 않을 수 있고, 200 ㎛를 초과하는 경우에는 미연탄소와 회재입자가 분리되지 않아 부유 선별의 효율이 저하될 수 있다. The size of the pulverized and finely pulverized coal material is preferably 100 to 200 탆 passing through 65 mesh, and float sorting can be easily performed due to the size of the pulverized and pulverized coal material. When the size of the crushed and pulverized coal ash is less than 100 탆, it may be difficult to isolate individual particles by floating. When the particle size exceeds 200 탆, unburnt carbon and fly ash particles are not separated, .
또한, 상기 파쇄 및 미분쇄된 석탄재에 물을 첨가하여 슬러리로 제조한 후 로드 밀을 이용하여 습식 밀링할 수 있고, 석탄재에 포함된 미연탄소는 지오폴리머화 반응에 방해가 되기 때문에 부유 선별로 제거할 수 있다. 상기 부유 선별은 조선부선(roughing, 粗選)하는 단계와 청소부선(scavenging, 淸掃選) 단계로 구성될 수 있다. Further, water can be added to the pulverized and finely pulverized coal materials to prepare a slurry, followed by wet milling using a rod mill, and since unburnt carbon contained in the coal material interferes with the geopolymerization reaction, can do. The float sorting may include a roughing step and a scavenging step.
상기 부유 선별 후 석탄재를 세척한 후 탈수시키고 오븐에서 건조시켜 지오폴리머 생산을 위한 원료 물질로 사용한다. 상기 방법으로 제조된 지오폴리머 생산을 위한 석탄재에 활성화제를 첨가하여 시멘트 믹서에서 혼합한 후 양생하여 지오폴리머를 제조할 수 있다. After the fly ash separation, the coal ash is washed, dehydrated and dried in an oven to be used as a raw material for the production of a geopolymer. The activator may be added to the coal ash for the production of the geopolymer produced by the above method, mixed with the cement mixer, and cured to prepare the geopolymer.
이때, 상기 활성화제는 규산 나트륨 및 수산화나트륨을 포함하고, 지오폴리머 내에 Si:Al의 몰비와 Na:Al의 몰비가 각각 1.5 - 2.8 및 1.2 - 1.5가 되도록 포함되는 것이 바람직하다. 상기 Si:Al의 몰비를 1.5 - 2.8로 하여 폴리(시아레이트-실옥소)(poly(sialate siloxo))를 제조할 수 있고, Na:Al의 몰비는 Na가 휘발성이므로 1.2 - 1.5가 되도록 하여 백화(efflorescence) 현상을 방지할 수 있다. Preferably, the activator comprises sodium silicate and sodium hydroxide, and the molar ratio of Si: Al and the molar ratio of Na: Al in the geopolymer are 1.5-2.8 and 1.2-1.5, respectively. (Poly (sialate siloxo)) can be prepared by setting the mole ratio of Si: Al to 1.5-2.8. The molar ratio of Na: Al is 1.2-1.5 because Na is volatile, (efflorescence) phenomenon can be prevented.
상기 제조된 지오폴리머는 집속 이온빔 밀링으로 판상 구조의 지오폴리머로 제조되고, 갈륨(gallium) 이온으로 절삭한 후 연마하여 밀링 결함을 최소화할 수 있다. The prepared geopolymer is produced as a geopolymer having a plate-like structure by focused ion beam milling and can be milled after cutting with gallium ions to minimize milling defects.
본 발명에 따른 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법은 상기 제조된 판상 지오폴리머를 연속적으로 기울여서 투과전자현미경으로 관찰한 후 CCD 카메라(charge-coupled device camera)로 촬영하는 단계(S110)를 포함한다. The method for three-dimensionally measuring a porous geopolymer using the electron tomography according to the present invention comprises the steps of continuously obliquely observing the prepared sheet-like geopolymer with a transmission electron microscope, and then photographing with a CCD-camera (charge-coupled device camera) ).
상기 제조된 판상 지오폴리머는 1°간격으로 -55°에서 +55°까지 연속적으로 기울여 투과전자현미경(TEM)으로 관찰한 후 CCD 카메라를 이용하여 촬영될 수 있다. 상기 투과전자현미경은 120 keV의 에너지로 판상 지오폴리머를 관찰하여 명시야상(bright field image)을 얻을 수 있고, 얻어진 이미지를 CCD 카메라로 촬영한다. The prepared sheet-like geopolymers can be continuously photographed at -55 ° to + 55 ° at intervals of 1 °, observed with a transmission electron microscope (TEM), and then photographed using a CCD camera. The transmission electron microscope can obtain a bright field image by observing the plate-shaped geopolymer with an energy of 120 keV, and photographs the obtained image with a CCD camera.
본 발명에 따른 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법은 상기 촬영된 사진을 필터보정 역투영법(filtered back-projection)을 이용하여 3차원으로 재구성하는 단계(S120)를 포함한다. The method for three-dimensional measurement of porous geopolymers using electron tomography according to the present invention includes reconstructing the photographed photographs three-dimensionally using filtered back-projection (S120).
상기 촬영된 사진은 필터보정 역투영법을 이용하여 3차원으로 재구성되는데 3차원으로 재구성된 단층사진은 Chimera 소프트웨어 v.16 및 IMOD v.4.1.10.을 이용하여 분석될 수 있다. The photographed photographs are reconstructed in three dimensions using a filter back projection method. The reconstructed tomographic photographs can be analyzed using Chimera software v.16 and IMOD v.4.1.10.
상기 다공성 지오폴리머의 3차원 측정방법은 다공성 지오폴리머에 포함된 나노 크기 기공을 분석할 수 있다. The three dimensional measurement method of the porous geopolymer can analyze nano-sized pores contained in the porous geopolymer.
또한, 본 발명은 지오폴리머를 이온빔으로 밀링하여 판상 구조의 지오폴리머를 제조하는 단계; The present invention also relates to a method for producing a geopolymer comprising the steps of: milling a geopolymer with an ion beam to prepare a geopolymer having a plate-like structure;
상기 제조된 판상 지오폴리머를 금 콜로이드 용액에 침지시킨 후 건조시켜 금 입자를 도포하는 단계; Immersing the prepared flaky geopolymer in a gold colloid solution and then drying to apply gold particles;
상기 금 입자가 도포된 판상 지오폴리머를 연속적으로 기울여서 투과전자현미경으로 관찰한 후 CCD 카메라(charge-coupled device camera)로 촬영하는 단계; 및 Continuously observing the sheet-like geopolymer coated with the gold particles with a transmission electron microscope, and photographing the sheet with a charge-coupled device camera; And
상기 촬영된 사진을 필터보정 역투영법(filtered back-projection)을 이용하여 3차원으로 재구성하는 단계;를 포함하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법을 제공한다.And reconstructing the photographed image three-dimensionally using filtered back-projection. The present invention also provides a method for three-dimensionally measuring a porous geopolymer using electron tomography.
상기 판상 지오폴리머에 도포되는 금 입자의 크기는 10 ㎚인 것이 바람직하며, 각도 변화에 따른 정밀한 정렬을 위한 지표로 사용될 수 있다. The size of the gold particles applied to the flaky geopolymer is preferably 10 nm and can be used as an index for precise alignment according to an angle change.
실시예 1: 다공성 지오폴리머의 3차원 측정Example 1: Three-dimensional measurement of a porous geopolymer
1. 석탄재로부터 지오폴리머의 원료물질 제조 1. Production of raw material of geopolymer from coal ash
지오폴리머 시료는 삼천포화력발전소에서 제공되는 소량의 굵은 잔사회(rejected fly ash)가 혼합된 바닥재(bottom ash)인 매립회(pond ash)를 사용하였다. 바닥재는 굵은 다공성 석탄 입자이고, 갈색빛을 띄는 회색이다. 잔사회는 높은 미연탄소 함량과 큰 입자 크기(45 ㎛ 초과) 때문에 매립지에 버려진 비산재의 굵은 부분이다. 석탄재(ash)를 매립회에서 수집하고, 상온에서 3일 동안 건조시켰다. 그 후 65 메쉬(212 ㎛)를 43%로 통과하는 분말도를 갖도록 파쇄하고 미분쇄하였다. 500g의 분쇄된 석탄재를 500 mL의 물에서 슬러리로 제조하였으며, 로드 밀(rod mill)을 이용하여 212 ㎛ 미만의 크기로 습식 밀링하였다. 미연탄소 함량은 공업 분석(proximate analysis)으로 측정하였으며, 미연탄소는 지오폴리머화 반응에 방해가 되기 때문에 부유 선별(froth flotation)로 제거하였다. 약 60 g/t의 포수제(kerosene)와 20 g/t의 기포제(fine oil)를 입자의 표면에 선택적으로 흡수되도록 하였으며, 결합된 탄소 입자들이 손실되지 않도록 안정하게 포말(froth)되게 하였다. 약 600 g/t의 분산제(Na2SiO3)를 사용하여 이종 응집을 최소화하고, 선택성(selectivity)을 촉진시켰다. 부유 선별은 조선부선(roughing)의 제1 단계와 청소부선(scavenging)의 제2 단계로 구성된다. 부유 선별 후 세척된 석탄재를 탈수시키고 하루 동안 오븐에 건조시켜 지오폴리머를 생산하기 위한 원료로 사용하였다. 세척된 석탄재의 탄소량은 공업 분석으로 측정하였다. The geopolymer samples were pond ash, a bottom ash mixed with a small amount of rejected fly ash from Samchunpo Thermal Power Plant. The flooring is coarse, porous coal particles, brownish gray. The remainder is a thick part of fly ash that is abandoned in landfills because of its high unburned carbon content and large particle size (> 45 μm). Ash (ash) was collected in a landfill and dried at room temperature for 3 days. Thereafter, the 65 mesh (212 탆) was pulverized and pulverized to have a powder throughput of 43%. 500 g of pulverized coal ash was slurried in 500 mL of water and wet milled to a size of less than 212 μm using a rod mill. The unburned carbon content was measured by proximate analysis and the unburned carbon was removed by froth flotation because it interfered with the geopolymerization reaction. About 60 g / t of kerosene and 20 g / t of fine oil were selectively absorbed on the surface of the particles, and the bonded carbon particles were frosted so as not to be lost. A dispersant (Na 2 SiO 3 ) of about 600 g / t was used to minimize heterogeneous aggregation and promote selectivity. Flotation screening consists of the first stage of roughing and the second stage of scavenging. Flocculant After washing, the washed coal ash was dehydrated and dried in an oven for one day to be used as a raw material for producing a geopolymer. The amount of carbon in the washed coal ash was measured by industrial analysis.
2. 지오폴리머 제조 2. Geopolymer production
규산 나트륨 용액(SiO2 36.50%, Na2O 18.00%, Kanto Chemical Co., INC)과 수산화나트륨(Wako Pure Chemical Industries, Ltd)을 활성화제로 사용하여 Si:Al의 비가 2.0이고 Na:Al의 비가 1.2인 지오폴리머를 제조하였다. 석탄재와 활성화제의 혼합물을 시멘트 믹서에서 15분간 혼합한 후 5 ㎝ 큐브 틀에 붓고 밀봉하여 70 ℃에서 24 시간 양생한 후 틀에서 분리하였다. 하루 양생 후 석탄재와 활성화제 혼합물 페이스트(paste)의 압축강도는 49.8 MPa이고, 표준 편차는 4.7 MPa이였다. And Al ratio of 2.0 Na:: sodium silicate solution (SiO 2 36.50%, 18.00% Na 2 O, Kanto Chemical Co., INC) and sodium hydroxide (Wako Pure Chemical Industries, Ltd) a Si to Al ratio of activator 1.2. ≪ / RTI > The mixture of coal ash and activator was mixed in a cement mixer for 15 minutes, poured into a 5 cm cube mold, sealed, cured at 70 ° C for 24 hours and then separated from the mold. After one day curing, the compressive strength of coal ash and activator mixture paste was 49.8 MPa and the standard deviation was 4.7 MPa.
3. TEM 데이터 획득 및 3차원 재구성 방법3. TEM data acquisition and 3D reconstruction method
지오폴리머 겔로 확인되고 석탄 전구체와 반응하지 않는 부분으로부터 집속이온빔 밀링(Quanta 3D FEG, FEI)으로 판상 구조의 지오폴리머를 제조하였다. 30 keV 및 15 nA에서 갈륨 이온으로 절삭한 후 5 keV 및 48 pA에서 연마하여 밀링 결함을 최소화하였다. 금 콜로이드 용액을 증류수로 10배 희석하여 10 ㎚ 금 입자를 시료의 위, 아래 표면에 입혀 각도 변화의 정밀한 정렬을 위한 지표로 사용하였다. 시편 위에 금 입자를 위치시키기 위해, 판상 구조의 지오폴리머를 1 분 동안 희석된 금 콜로이드 용액에 담근 후 건조시켜 금 입자를 시편 양 표면에 위치시켰다. 영상 획득을 위해 큰 경사각 홀더와 2048×2048 픽셀 CCD 카메라가 장착된 FEI TECNAI G2 Spirit를 이용하여 TEM 이미지를 얻었다. 판상 구조 지오폴리머의 각도 변화에 따른 명시 야상(bright field image, 120 keV의 가속력)은 경사각 1°의 간격에서 -55°에서 +55°까지 얻었다. 각도 변화에 따른 정확한 정렬은 전자 단층촬영에서 필수적인 단계이며, 각도 변화에 따른 정렬을 위해 Diez et al.을 개선하여 새로운 공식을 사용하였다. TEM 이미지의 3차원 재구성(reconstruction)을 위해 사용되는 필터 역투영법(filtered back-projection)을 이용하였다. 각각의 이미지 크기는 컴퓨터 계산시간을 최소화하기 위해 1024 픽셀×1024 픽셀의 평균 픽셀로 이미지 크기를 반으로 감소시켰다. 재구성된 단층사진은 Chimera 소프트웨어 v.16 및 IMOD v.4.1.10.을 이용하여 분석하였다. Platelet-shaped geopolymers were prepared from focused ion beam milling (Quanta 3D FEG, FEI) from the areas identified as geopolymer gels and not reacting with the coal precursor. Cutting with gallium ions at 30 keV and 15 nA, then polishing at 5 keV and 48 pA minimized milling defects. The gold colloid solution was diluted 10 times with distilled water and 10 ㎚ gold particles were applied to the upper and lower surfaces of the sample and used as indexes for precise alignment of angle changes. To place the gold particles on the specimen, the platelet-shaped geopolymer was immersed in a diluted gold colloid solution for 1 minute and then dried to place the gold particles on both surfaces of the specimen. TEM images were obtained using FEI TECNAI G 2 Spirit equipped with a large inclination holder and a 2048 × 2048 pixel CCD camera. The bright field image (acceleration of 120 keV) along the angle of the plate geometry was obtained from -55 ° to + 55 ° at an angle of 1 ° inclination. Accurate alignment with angle changes is an essential step in the electronic tomography and Diez et al. Filter back-projection, which is used for three-dimensional reconstruction of the TEM image, was used. Each image size reduced the image size in half by an average pixel of 1024 pixels by 1024 pixels to minimize computer computation time. Reconstructed tomographic images were analyzed using Chimera software v.16 and IMOD v.4.1.10.
실험예 1: 석탄재의 화학적 조성 및 상 분석Experimental Example 1: Chemical composition and phase analysis of coal ash
본 발명에 따른 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법에서 탄소재의 화학적 조성 및 상을 분석하였다. The chemical composition and phase of the carbonaceous material were analyzed in the three dimensional measurement method of the porous geopolymer using the electron tomography according to the present invention.
도 2에 나타난 바와 같이, 수집된 매립회는 다양한 크기와 형상을 나타내었다(도 2의 (a) 참고). 바닥재는 큰 입자 크기를 가지며 다공성이고 모래 형상이며 갈회색이었다(도 2의 (b) 참고). 대부분의 석탄 입자는 소량의 철, 칼슘, 칼륨, 마그네슘 및 나트륨을 갖는 규산 알루미늄 상이었다(도 2의 (c) 참고). 하기 표 1은 미연탄소가 제거된 매립회의 화학적 조성을 XRF로 분석한 결과이다. As shown in Fig. 2, the collected buried sludge showed various sizes and shapes (see Fig. 2 (a)). The bottom material was porous with a large particle size, sandy and grayish gray (see Fig. 2 (b)). Most of the coal particles were on aluminum silicate with small amounts of iron, calcium, potassium, magnesium and sodium (cf. Fig. 2). Table 1 below shows the results of XRF analysis of the chemical composition of the landfill with unburned carbon removed.
표 1
조성 SiO2 Al2O3 Fe2O3 CaO MgO K2O Na2O TiO2 MnO P2O5 강열감량
함량 57.7 22.6 9.70 4.13 1.48 1.47 0.68 1.12 0.13 0.32 0.39
Table 1
Furtherance SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO K 2 O Na 2 O TiO 2 MnO P 2 O 5 Weight loss
content 57.7 22.6 9.70 4.13 1.48 1.47 0.68 1.12 0.13 0.32 0.39
상기 표 1을 참고하면, 매립회는 주로 SiO2 57.7%, Al2O3 22.6% 및 Fe2O3 9.70%로 구성되어 있으며, CaO는 4.13%만 함유되어 있었다. 탄소 잔류량은 4.69%였다. 미연탄소가 제거된 석탄재에서는 공업분석 결과 탄소가 발견되지 않았다. Referring to Table 1, the landfill was composed mainly of 57.7% of SiO 2 , 22.6% of Al 2 O 3 and 9.70% of Fe 2 O 3 , and contained only 4.13% of CaO. The residual carbon content was 4.69%. No carbon was found in the coal ash after removal of unburned carbon.
석탄재의 리트벨트 정량분석 결과, 석탄재의 주요 결정 상은 석영(quartz, 16.1 wt%), 멀라이트(mullite, 15.5 wt%), 알바이트(albite, 7.4 wt%) 및 적철석((hematite, 1.5 wt%)을 포함하였다. 비정질 부분은 59.5 wt%이었고, 비정질 부분의 조성은 벌크 화학 조성과 산화물로서 결정질 구성 성분의 차이로 계산되었다. 하기 표 2는 매립회의 비정질 부분의 화학 조성을 나타낸 것이다. The main crystal phases of coal ash were quartz, 16.1 wt%, mullite, 15.5 wt%, albite, 7.4 wt% and hematite, 1.5 wt% The amorphous portion was 59.5 wt% and the composition of the amorphous portion was calculated as the difference between the bulk chemical composition and the crystalline constituents as oxide. Table 2 below shows the chemical composition of the amorphous portion of the landfill.
표 2
조성 SiO2 Al2O3 Fe2O3 CaO MgO K2O TiO2 MnO P2O5
함량 25.9 17.1 8.3 4.2 1.5 1.5 1.1 0.1 0.3
Table 2
Furtherance SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO K 2 O TiO 2 MnO P 2 O 5
content 25.9 17.1 8.3 4.2 1.5 1.5 1.1 0.1 0.3
미연탄소가 제거된 석탄재의 Si:Al 비는 1.30으로 결정하였다. 규소와 나트륨은 Si/Al의 몰비가 2.0이고, Na/Al의 몰비는 1.2가 되게 석탄재에 첨가되었다. 지오폴리머 겔의 혼합비율은 석탄재 61.5 wt%, 규산 용액 24.3 wt%, NaOH 4.2 wt% 및 증류수 10 wt%였다. The Si: Al ratio of coal ash removed unburned carbon was determined to be 1.30. Silicon and sodium were added to the coal ash so that the molar ratio of Si / Al was 2.0 and the molar ratio of Na / Al was 1.2. The mixing ratio of the geopolymer gel was 61.5 wt% of coal ash, 24.3 wt% of silicate solution, 4.2 wt% of NaOH and 10 wt% of distilled water.
실험예 2: 지오폴리머에서의 나노 크기의 기공 구조 분석Experimental Example 2: Analysis of nanoscale pore structure in a geopolymer
본 발명에 따른 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법에서 제조된 지오폴리머의 기공을 분석하였다. The porosity of the geopolymer prepared by the three-dimensional measurement method of the porous geopolymer using the electron tomography according to the present invention was analyzed.
도 4는 판상 지오폴리머의 TEM 명시 야상이다. 도 4에 나타난 바와 같이, 판상 지오폴리머의 기공 구조는 페이스트와 기공 사이의 높은 명암차로 인해 뚜렷하게 나타났으며, 연속적인 각도 변화에서 브래그 산란 명암(bragg scattering contrast) 때문에 어두운 구형 금 입자 및 수많은 작은 결정들이 식별가능하였다. 겔 상이 비정질임에도 지오폴리머 내에 결정상이 존재하였다. 결정상은 금 입자보다 대개 크고, 어두웠으며, 비대칭이었다. 금 입자로부터 발생되는 확산 회절고리(diffuse diffraction ring)는 전자 회절 분석에서 나타났으며, 결정상에서 발생되는 회절 도형(diffraction spot) 또는 링은 나타나지 않았다. 회절 패턴에서 뚜렷한 도형 또는 링은 장거리 규칙성의 정도를 반영한다. 한편, 정렬되지 않은 나노입자들은 극히 작은 크기 때문에 식별가능한 회절 도형 또는 링을 제공하지 않았다. 이런 이유로, 결정질상은 에너지 산란 X-선 분광분석 데이터를 토대로 규칙성이 낮은 제올라이트인 것으로 판단된다. 제오폴리머 반응에서 제올라이트가 어느 정도 형성되는 것으로 판단된다. Figure 4 is a TEM light field of a sheet-form geopolymer. As shown in FIG. 4, the pore structure of the flaky geopolymer was apparent due to the high contrast difference between the paste and the pores. Due to bragg scattering contrast at successive angular changes, dark spherical gold particles and numerous small crystals Were identified. The crystalline phase was present in the geopolymer even though the gel phase was amorphous. The crystal phase was generally larger, darker, and asymmetric than gold particles. The diffuse diffraction ring generated from the gold particles was found in the electron diffraction analysis and no diffraction spot or ring appeared on the crystal. The distinctive shape or ring in the diffraction pattern reflects the degree of long-range regularity. On the other hand, unaligned nanoparticles did not provide an identifiable diffraction pattern or ring because of their extremely small size. For this reason, the crystalline phase is judged to be a low-order zeolite based on energy scattering X-ray spectroscopic data. It is judged that zeolite is formed to some extent in the zeolite reaction.
도 5는 약 10.7 ㎚ 간격으로 이격된 두개의 z-슬라이스 이미지를 나타낸 사진이다. 일부 기공의 외경지름을 도 4의 (a) 및 (b)에 표시하였다. 대다수의 기공은 거의 원형 또는 타원이었으나, 일부는 형상이 다소 무정형이었다. Figure 5 is a photograph showing two z-slice images spaced apart by about 10.7 nm. The outer diameters of some pores are shown in Figs. 4 (a) and 4 (b). Most of the pores were almost circular or elliptical, but some were somewhat amorphous in shape.
도 6은 4개의 z-슬라이스에서의 원으로 표시된 각각의 기공 크기 분포를 나타낸 그래프이다. 도 6에 나타난 바와 같이, 4개의 z-슬라이스에서의 145개 기공의 외경의 지름은 13.5 - 147 ㎚의 범위였다. 다수의 기공 크기는 20 - 60 ㎚ 정도였고, 상기 범위를 벗어나는 기공은 8개 였으며, 가늘고 긴 기공(도 4의 (b)에서 원으로 표시된 부분)은 80 ㎚ 이상이었다. 다수 기공은 슬라이스가 10.7 ㎚ 간격이어서 두개 또는 그 이상의 슬라이스에 존재한다. 따라서, 이러한 크기 범위가 145개의 기공 직경을 나타내는 것은 아니지만, 기공의 크기에 대한 근사치를 제공한다. 6 is a graph showing the pore size distribution of each of the circles in the four z-slices. As shown in Fig. 6, the diameters of the outer diameters of 145 pores in the four z-slices ranged from 13.5 to 147 nm. The number of pores was about 20 to 60 nm, the number of pores out of the range was 8, and the pores having long and narrow pores (the part circled in FIG. 4 (b)) were 80 nm or more. Multiple pores are present in two or more slices with a slice spacing of 10.7 nm. Thus, this size range does not represent 145 pore diameters, but provides an approximation of the size of the pores.
실험예 3: 나노크기에서의 지오폴리머 기공 분석Experimental Example 3: Analysis of Geopolymer Pore at Nano Size
지오폴리머 내의 공극율을 정량적인 값으로 나타내기 위해 도 7에 나타난 바와 같이 구분화(segmentation)하여 3차원으로 재구성하였다. 구분화는 서로 다른 상을 구별하기 위해 상이한 명암값을 토대로 픽셀을 그룹화하는 과정이다. 예를 들어, 기공은 지오폴리머 내의 겔로부터 큰 명암차이로 구분된다. 그러나, 자동화된 프로그램을 이용하지 않고 수작업으로 명암을 구분하는 수동 구분화에는 시간이 많이 소비되며, 주관적일 수 있다는 것이다. 이진화(thresholding)에 의한 구분화를 토대로한 정량화는 이미지를 다른 상으로 빠르게 구분할 수 있다. 따라서, 본 발명은 이진화가 z-슬라이스에서 기공과 겔을 완전히 구분화하지 못할 수도 있기 때문에 수동 구분화에 의해 기공을 정량화하였다. 희석된 금 콜로이드 용액에 판상 지오폴리머를 담근 후 건조시키는 공정은 판상 지오폴리머를 서서히 구부러지게 하고, 공극율을 정량화하기 위한 관심 부피를 감소시킨다. 구분화를 위해 선택된 판상 지오폴리머의 폭, 길이 및 두께는 각각 482 ㎚, 482 ㎚ 및 32.2 ㎚이고, 부피는 0.00748 μ㎥였으며, 이는 도 4에 나타난 이미지를 3차원 재구성한 부피 0.0387 μ㎥의 19.3%에 해당하는 값이다. 상기 영역에서의 공극율은 7.15%로 나타났다. 상기 값은 종래 방법으로 측정된 30.5%, 23~28%보다 휠씬 낮은 값이다. 이러한 차이는 원료물질의 상이한 화학 조성, 제제(formulation), 양생조건, 샘플의 제조년도에 따라 상이할 수 있지만, 무엇보다도 공극율 측정 장치에서의 해상도 및 부피 차이와 관련된다. 전자 단층촬영은 수십 밀리미터 이상의 큰 물체에 사용되는 수은 압입법(MIP), 금속 압입법 및 X-선 단층촬영과 같은 공극율 측정 방법보다 높은 해상도로 나노미터 수준에서 매우 작은 부피에 대해 기공 구조를 분석할 수 있다. 수백 나노미터 이상의 큰 기공은 마이크론에서부터 5 ㎚ 미만 범위의 크기와 공존하고, 기공 크기는 100 ㎚에서 10 ㎚ 범위이다. 도 6에 나타난 바와 같이, 미세 기공의 존재를 시각으로 직접 관찰할 수 있다. 재구성된 이미지에서의 결함(artifact)은 기공보다 휠씬 작은 크기의 웜홀(wormhole) 구조를 가지며, 판상 지오폴리머에 존재하는 제올라이트 결정의 산란 노이즈로부터 발생된다. 명시야 전자 단층촬영에서 재구성을 위한 일반적인 알고리즘은 필터 역 투사(filtered back projection, FBP) 및 동시 반복영상 구성 기술(simultaneous iterative reconstruction technique, SIRT)이고, 이들 알고리즘은 결정질 입자가 포함되어 있는 경우 3차원 재구성을 수행하면 항상 결함을 발생시킨다. 결정에서 어두운 부분들의 공간 분포는 전체 순차적인 각도 변화의 재구성에 의해 상쇄될 수 있다. 그러므로, 웜홀 구조는 브래그 산란(bragg scattering)으로 발생되는 명도 오차의 효과 및 고상 영역에서의 불균일한 화학적 조성으로 인해 형성되는 것으로 판단된다. 그러나, 이러한 결함은 z-슬라이스 이미지 또는 재구성된 3차원 이미지 내에서 기공의 형태 또는 크기와 같은 시각적 세부사항들을 심각하게 왜곡하지는 않으므로, 기공 크기 데이터는 신뢰할 수 있다. In order to express the porosity in the geopolymer as a quantitative value, it was segmented and reconstructed into three dimensions as shown in Fig. The segmentation is a process of grouping pixels based on different contrast values to distinguish between different images. For example, pores are distinguished by large contrast differences from the gel in the geopolymer. However, manual sorting, which manually distinguishes between contrasts without using an automated program, can be time-consuming and subjective. Quantification based on classification by thresholding can quickly distinguish images from other images. Thus, the present invention quantifies pores by manual sorting because the binarization may not be able to completely separate pores and gels in z-slices. The process of immersing the sheet-like geopolymer in a diluted gold colloid solution and then drying will cause the sheet-form geopolymer to bend slowly and reduce the volume of interest for quantifying the porosity. The width, length, and thickness of the sheet-form geopolymers selected for sorting were 482 nm, 482 nm, and 32.2 nm, respectively, and the volume was 0.00748 mu m, which is a value of 19.3 It is a value corresponding to%. The porosity in this region was 7.15%. This value is much lower than the 30.5% and 23 ~ 28% measured by the conventional method. These differences may be different depending on the different chemical composition, formulation, curing conditions of the raw material, and the year of manufacture of the sample, but above all are related to the resolution and volume difference in the porosimetry device. Electron tomography analyzes pore structures for very small volumes at the nanometer level at higher resolutions than mercury porosimetry (MIP), metal infiltration and X-ray tomography methods used for larger objects of several tens of millimeters or more. can do. Large pores of several hundred nanometers or more coexist with sizes ranging from microns to less than 5 nm, and pore sizes range from 100 nm to 10 nm. As shown in FIG. 6, the presence of micropores can be observed directly by visual observation. The artifacts in the reconstructed image have a wormhole structure much smaller than the pores and arise from the scattering noise of the zeolite crystals present in the plate geometry polymer. Typical algorithms for reconstruction in bright field electron tomography are filtered back projection (FBP) and simultaneous iterative reconstruction technique (SIRT). These algorithms are based on three-dimensional Performing reconfiguration always causes defects. The spatial distribution of the dark portions in the crystal can be offset by the reconstruction of the entire sequential angle change. Therefore, it is considered that the wormhole structure is formed due to the effect of lightness error caused by bragg scattering and the uneven chemical composition in the solid phase region. However, since such defects do not seriously distort the visual details such as the shape or size of the pores within the z-slice image or the reconstructed three-dimensional image, the pore size data is reliable.
도 7은 판상 지오폴리머의 재구성된 단층사진을 3차원으로 렌더링(rendering)한 사진이다. 도 7에 나타난 바와 같이, 대부분의 기공은 연결되어 있지 않으며, 일부 큰 기공들은 인접한 작은 다수의 기공들이 결합하여 형성된 것처럼 보인다. 3차원 단층사진에서 기공들의 불규칙적인 구조는 z-슬라이스 이미지에서 관찰된 바와 일치하는 것으로 보인다. 전술한 바와 같이, 암시야 주사투과전자현미경(ADF-STEM)의 전자 단층촬영은 지오폴리머를 연구하는데 더욱 적절한 것으로 판단되나, 명시야 모드의 1/5 미만의 낮은 분해능을 가지는 단점이 있다. 본 발명에서 확인된 것보다 작은 기공들은 고배율 전자 단층촬영으로 밝혀낼 수 있다. 한편, 미싱 웨지 효과는 ±70°까지의 경사각 한계 때문에 발생되고, 3차원 재구성에서 투영 감소 때문에 결함이 발생한다. 공극율은 측정하고자 하는 시료가 ±90° 이상으로 기울어지는 경우 변화되고, 미싱 웨지 효과를 완전히 없앨 수 있다. 그러나, 본 발명에서 얻어지는 공극율은 지오폴리머 겔에서의 미세 기공의 3차원 정량 평가이고, 나노미터 수준의 공간 해상도에서 지오폴리머의 기공 구조를 더욱 구체적으로 이해할 수 있는 방법을 제공한다. 하나의 방법으로 시료에서의 기공 크기 범위를 완전히 특정화할 수는 없으나, 본 발명의 방법은 TEM 및 필터보정 역투영법을 이용하는 전자 단층촬영으로 X-선 단층촬영에서는 얻을 수 없는 나노미터 해상도에서 지오폴리머의 3차원 기공 네트워크 및 기공 연결성에 대한 직접적인 정보를 얻을 수 있다. FIG. 7 is a photograph of a three-dimensional rendering of a reconstructed tomographic photograph of a sheet-form geopolymer. FIG. As shown in FIG. 7, most of the pores are not connected, and some large pores appear to be formed by a combination of a plurality of adjacent small pores. The irregular structure of the pores in a 3-D tomographic image appears to be consistent with that observed in the z-slice image. As described above, the electron tomography of the dark night scanning transmission electron microscope (ADF-STEM) is considered to be more appropriate for studying the geopolymer, but has a disadvantage in that it has a low resolution of less than 1/5 of the bright field mode. Pores smaller than those identified in the present invention can be identified by high magnification electron tomography. On the other hand, the missing wedge effect is caused by the inclination angle limit up to + 70 °, and defects occur due to the reduction in projection in three-dimensional reconstruction. The porosity changes when the sample to be measured is tilted to more than ± 90 °, and the sewing wedge effect can be completely eliminated. However, the porosity obtained in the present invention is a three-dimensional quantitative evaluation of micropores in a geopolymer gel, and provides a method for more specifically understanding the pore structure of a geopolymer at a spatial resolution on the order of nanometers. One way is not to completely characterize the pore size range in the sample, but the method of the present invention is based on the use of TEM and filter corrected back-projection electron tomography in which nanopores at nanometer resolution Dimensional pore network and pore connectivity.
지금까지 본 발명에 따른 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법에 관한 구체적인 실시예에 관하여 설명하였으나, 본 발명의 범위에서 벗어나지 않는 한도 내에서는 여러 가지 실시 변형이 가능함은 자명하다.It should be understood that the present invention is not limited to the three-dimensional measurement method of the porous geopolymer using the electron tomography according to the present invention, but various modifications may be made without departing from the scope of the present invention.
그러므로 본 발명의 범위에는 설명된 실시예에 국한되어 전해져서는 안 되며, 후술하는 특허청구범위뿐만 아니라 이 특허청구범위와 균등한 것들에 의해 정해져야 한다.Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.
즉, 전술된 실시예는 모든 면에서 예시적인 것이며, 한정적인 것이 아닌 것으로 이해되어야 하며, 본 발명의 범위는 상세한 설명보다는 후술될 특허청구범위에 의하여 나타내어지며, 그 특허청구범위의 의미 및 범위 그리고 그 등가 개념으로부터 도출되는 모든 변경 또는 변형된 형태가 본 발명의 범위에 포함되는 것으로 해석되어야 한다.It is to be understood that the foregoing embodiments are illustrative and not restrictive in all respects and that the scope of the present invention is indicated by the appended claims rather than the foregoing description, It is intended that all changes and modifications derived from the equivalent concept be included within the scope of the present invention.

Claims (12)

  1. 지오폴리머를 이온빔으로 밀링하여 판상 구조의 지오폴리머를 제조하는 단계;Milling a geopolymer with an ion beam to produce a geopolymer having a plate-like structure;
    상기 제조된 판상 지오폴리머를 연속적으로 기울여 투과전자현미경으로 관찰한 후 CCD 카메라(charge-coupled device camera)로 촬영하는 단계; 및Continuously obliquely observing the prepared sheet-like geopolymer with a transmission electron microscope and photographing with a CCD camera (charge-coupled device camera); And
    상기 촬영된 사진을 필터보정 역투영법(filtered back-projection)을 이용하여 3차원으로 재구성하는 단계;를 포함하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법.And reconstructing the photographed image three-dimensionally using filtered back-projection. 2. The method according to claim 1, wherein the photographed photographed image is reconstructed three-dimensionally using filtered back-projection.
  2. 제1항에 있어서, The method according to claim 1,
    상기 지오폴리머는 매립회로부터 석탄재를 수집한 후 파쇄 및 미분쇄하고 활성화제와 혼합하여 제조되는 것을 특징으로 하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법.Wherein the geopolymer is prepared by collecting coal ash from the buried circuit, and then crushing and pulverizing the mixture and mixing with an activating agent.
  3. 제2항에 있어서,3. The method of claim 2,
    상기 파쇄 및 미분쇄된 석탄재의 크기는 100 - 200 ㎛인 것을 특징으로 하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법. Wherein the size of the crushed and pulverized coal ash is 100-200 탆.
  4. 제2항에 있어서,3. The method of claim 2,
    상기 파쇄 및 미분쇄 공정 후 로드 밀을 이용하여 습식 밀링하는 단계를 더 포함하는 것을 특징으로 하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법. Further comprising wet milling using the rod mill after the crushing and milling process. ≪ Desc / Clms Page number 13 >
  5. 제4항에 있어서,5. The method of claim 4,
    상기 습식 밀링 후 석탄재에 포함된 미연탄소를 부유 선별로 제거하는 단계를 더 포함하는 것을 특징으로 하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법. Further comprising the step of removing the unburnt carbon contained in the coal ash after the wet milling by floating.
  6. 제2항에 있어서,3. The method of claim 2,
    상기 활성화제는 규산 나트륨 및 수산화나트륨을 포함하는 것을 특징으로 하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법. Wherein the activator comprises sodium silicate and sodium hydroxide. ≪ RTI ID = 0.0 > 11. < / RTI >
  7. 제1항에 있어서,The method according to claim 1,
    상기 연속 기울임은 1°간격으로 -55°에서 +55°까지 수행되는 것을 특징으로 하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법.Wherein the continuous tilt is performed from -55 DEG to + 55 DEG at intervals of 1 DEG.
  8. 제1항에 있어서,The method according to claim 1,
    상기 다공성 지오폴리머의 3차원 측정방법은 다공성 지오폴리머에 포함된 나노 크기 기공을 분석하는 것을 특징으로 하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법. A method for three-dimensionally measuring a porous geopolymer, the method comprising: analyzing nano-sized pores included in the porous geopolymer.
  9. 제1항에 있어서,The method according to claim 1,
    상기 지오폴리머는 Si:Al의 몰비가 1.5 - 2.8이고, Na:Al의 몰비가 1.2 - 1.5인 것을 특징으로 하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법.Wherein the geopolymer has a molar ratio of Si: Al of 1.5-2.8 and a molar ratio of Na: Al of 1.2-1.5.
  10. 지오폴리머를 이온빔으로 밀링하여 판상 구조의 지오폴리머를 제조하는 단계; Milling a geopolymer with an ion beam to produce a geopolymer having a plate-like structure;
    상기 제조된 판상 지오폴리머를 금 콜로이드 용액에 침지시킨 후 건조시켜 금 입자를 도포하는 단계; Immersing the prepared flaky geopolymer in a gold colloid solution and then drying to apply gold particles;
    상기 금 입자가 도포된 판상 지오폴리머를 연속적으로 기울여 투과전자현미경으로 관찰한 후 CCD 카메라(charge-coupled device camera)로 촬영하는 단계; 및 Continuously obliquely scanning the sheet-like geopolymer coated with the gold particles, observing the particles with a transmission electron microscope, and photographing the particles with a charge-coupled device camera; And
    상기 촬영된 사진을 필터보정 역투영법(filtered back-projection)을 이용하여 3차원으로 재구성하는 단계;를 포함하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법.And reconstructing the photographed image three-dimensionally using filtered back-projection. 2. The method according to claim 1, wherein the photographed photographed image is reconstructed three-dimensionally using filtered back-projection.
  11. 제10항에 있어서, 11. The method of claim 10,
    상기 지오폴리머는 매립회로부터 석탄재를 수집한 후 파쇄 및 미분쇄하고 활성화제와 혼합하여 제조되는 것을 특징으로 하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법.Wherein the geopolymer is prepared by collecting coal ash from the buried circuit, and then crushing and pulverizing the mixture and mixing with an activating agent.
  12. 제10항에 있어서,11. The method of claim 10,
    상기 연속 기울임은 1°간격으로 -55°에서 +55°까지 수행되는 것을 특징으로 하는 전자 단층촬영을 이용한 다공성 지오폴리머의 3차원 측정방법.Wherein the continuous tilt is performed from -55 DEG to + 55 DEG at intervals of 1 DEG.
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