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Delivery: <= 4 days. True-PDF full-copy in English will be manually translated and delivered via email. GB/T 40066-2021: Nanotechnologies - Thickness measurement of graphene oxide - Atomic Force Microscopy (AFM) Status: Valid
Basic dataStandard ID: GB/T 40066-2021 (GB/T40066-2021)Description (Translated English): Nanotechnologies - Thickness measurement of graphene oxide - Atomic Force Microscopy (AFM) Sector / Industry: National Standard (Recommended) Classification of Chinese Standard: A40 Word Count Estimation: 22,299 Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration GB/T 40066-2021: Nanotechnologies - Thickness measurement of graphene oxide - Atomic Force Microscopy (AFM)---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order. (Nanotechnology Graphene Oxide Thickness Measurement Atomic Force Microscopy) ICS 17.180 A40 National Standards of People's Republic of China Nanotechnology graphene oxide thickness measurement Atomic force microscopy Released on 2021-05-21 2021-12-01 implementation State Administration of Market Supervision and Administration Issued by the National Standardization Management Committee Table of contentsForeword Ⅰ Introduction Ⅱ 1 Scope 1 2 Normative references 1 3 Terms and definitions 1 4 Principles and calculation methods 1 5 Reagents and materials 3 6 Instruments and equipment 3 7 Sample preparation 3 8 Measurement step 3 9 Result calculation 3 10 Application of Graphene Oxide Thickness Measurement 5 11 Uncertainty 5 12 Test report 6 Appendix A (informative appendix) Method 1 example 7 Appendix B (informative appendix) Method 2 example 12 Appendix C (informative appendix) Graphene oxide thickness measurement application 16 Appendix D (informative appendix) Method 1 test report format 17 Appendix E (informative appendix) Method 2 test report format 18 Reference 19 Nanotechnology graphene oxide thickness measurement Atomic force microscopy1 ScopeThis standard specifies the sample preparation, measurement procedures, and calculation of results for the atomic force microscopy (AFM) measurement of graphene oxide thickness. This standard is applicable to the measurement of the thickness of graphene oxide with a diameter of not less than 300nm. AFM measurement of thickness of other two-dimensional materials The amount can be used by reference.2 Normative referencesThe following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document. GB/T 27760 Method for calibrating sub-nano height measurement of atomic force microscope using Si(111) crystal plane atomic steps GB/T 30544.13 Nanotechnology terminology Part 13.Graphene and related two-dimensional materials JJF1351 Scanning Probe Microscope Calibration Specification3 Terms and definitionsThe terms and definitions defined in GB/T 27760, GB/T 30544.13 and JJF1351 apply to this document. For ease of use, the following Some terms and definitions in GB/T 30544.13 are repeatedly listed. 3.1 Graphene oxide;GO The chemically modified graphene obtained after oxidation and exfoliation of graphite has a base plane that has been strongly oxidized. Note. Graphene oxide is a single-layer material with high oxygen content, usually characterized by the carbon-oxygen atomic ratio (related to the synthesis method, generally about 2.0). [GB/T 30544.13-2018, definition 3.1.2.13]4 Principles and calculation methods4.1 Principle Lay the graphene oxide sample flat on the substrate, use AFM to characterize the surface morphology of the graphene oxide and the substrate, and then use the software to perform The line background is subtracted to obtain the contour line, and the height difference between the upper step and the lower step is measured, which is the thickness of the graphene oxide sample. Calculated height The poor methods are divided into 4.2 and 4.3. 4.2 Calculation Method One The coordinates of each point of the upper and lower steps in the contour line are linearly fitted by the least square method, and two fitted straight lines (see Figure 1) and the pair are obtained. The corresponding fitting parameters a1, b1, a2, b2.Calculate the height difference H of the upper and lower steps by formula (1), which is the difference between the upper straight line and the lower straight line at point xT distance. 4.3 Calculation Method Two The corresponding data on both sides of the steps formed by the graphene oxide and the substrate is converted into a height probability distribution histogram (see Figure 2), using Gaussian simulation The normal distribution curve is obtained together, and the difference of the x-coordinate between the height peaks on both sides is the thickness of the sample, and the thickness value is calculated by formula (2). Note. The probability distribution histogram of the height data, where the black histogram represents the probability distribution of graphene oxide height, and the blue histogram represents the height of the substrate. The red line is the Gaussian fitting line obtained according to the formula in the figure. The upper and lower x are graphene oxide and the substrate obtained by Gaussian fitting The maximum value of the probability distribution of the height reached, the difference between the two is the sample thickness value.5 Reagents and materials5.1 Mica sheet. The surface flatness is atomic level. 5.2 Ultrapure water. conductivity is not more than 0.1μs/cm. 5.3 Ethanol. analytically pure.6 Equipment6.1 Atomic force microscope. the vertical direction (z direction) resolution is better than 0.1nm, and the number of scan lines in a single picture is not less than 500. 6.2 Ultrasonic disperser. power is not more than 300W. 6.3 Others. analytical balance, pipette, glass petri dish, tape, etc.7 Sample preparation7.1 The conditions of the sample preparation environment are temperature 20℃~30℃ and relative humidity not higher than 65%. 7.2 The environment and utensils should be kept clean during the sample preparation process, and pollutants should be avoided as much as possible. 7.3 Ensure that the prepared samples can be dispersed independently, and there is no stacking between the layers. Refer to Appendix A for sample preparation methods.8 Measurement steps8.1 The calibration of the atomic force microscope should comply with the regulations of JJF1351. 8.2 AFM scan parameters are set to tap mode, the number of scan lines is greater than 500, such as 512 or 1024, and the scan range is generally 10μm ×10μm or less. 8.3 Select a clear test image and save its original test data. In order to ensure the representativeness of the sample, at least 3 should be selected on the surface of the mica Graphene oxide in different effective areas is tested, a total of at least 10 (m) independent samples are selected for thickness measurement, and each sample is measured at least Try 3 (n) contour lines. Note. m and n are applicable to 11.1 Chinese formula (3).9 Result calculation9.1 Background deduction Perform the background subtraction operation on the AFM original image of the selected sample (see Appendix A), and the height of the substrate baseline on both sides of the measured area can be obtained. Image with consistent degree (see Figure 3).Appendix B(Informative appendix) Method two example B.1 Experiment content Example 2 of graphene oxide thickness measurement. B.2 Sample preparation Refer to A.2, A.3, A.4, A.5 for sample preparation, measurement steps, background subtraction, and contour selection process. B.3 Data processing Use the software analysis function to convert the height data on both sides of each selected step (base and sample) into height probability distributions. Rectangular graph, Gaussian fitting to get the maximum value of the probability distribution of the height of the base and the sample. Refer to the description of the analysis software used for specific processing methods. Recommended software Igor, Origin, Excel, etc. Take the Igor software as an example, select the Histogram option in the Analysis menu bar, manually select Sourcewave and the corresponding outputwave; then set bins related parameters according to the data in Sourcewave, including the number of bins, the starting value of bins, and The width of the bin. The width of the bin is determined by the number of data in Sourcewave. Generally, the less the data, the smaller the bin value, so It can ensure the measurement of the thickness of a small area sample. The specific operations are as follows. a) Import the base and sample height data respectively, see Figure B.1; b) The height probability distribution analysis is shown in Figure B.2; c) The height probability distribution fitting is shown in Figure B.3. ...... |
