GB/T 36081-2018 English PDF (GBT36081-2018)

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GB/T 36081-2018: Nanotechnology -- Characterization of CdSe quantum dot nanocrystal -- Fluorescence spectroscopy
GB/T 36081-2018
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 17.180
A 40
Nanotechnology - Characterization of CdSe quantum dot
nanocrystal - Fluorescence spectroscopy
ISSUED ON. MARCH 15, 2018
IMPLEMENTED ON. OCTOBER 01, 2018
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine of PRC;
National Standardization Administration.
Table of Contents
Foreword... 3
Introduction... 4
1 Scope... 5
2 Normative references... 5
3 Terms and definitions... 5
4 Method principle... 7
5 Instruments... 8
6 Samples... 8
7 Sample testing... 9
8 Testing report... 11
Appendix A (Informative) Testing of fluorescence emission spectra of CdSe quantum
dot nanocrystals... 13
Appendix B (Informative) Measurement of relative fluorescence quantum yield of
quantum dot nanocrystals... 15
Appendix C (Informative) Testing report of quantum dot nanocrystal fluorescence
emission spectrum... 19
References... 20
Nanotechnology - Characterization of CdSe quantum dot
nanocrystal - Fluorescence spectroscopy
1 Scope
This standard specifies the characterization method for the fluorescence emission
spectrum detection of cadmium selenide quantum dot nanocrystals.
This standard is applicable to the fluorescence emission spectrum characterization of
cadmium selenide quantum dot nanocrystals; the fluorescence emission spectrum
characterization of other nanomaterials can also refer to this standard.
2 Normative references
The following documents are essential to the application of this document. For the dated
documents, only the versions with the dates indicated are applicable to this document;
for the undated documents, only the latest version (including all the amendments) is
applicable to this standard.
GB/T 19267.2 Physical and chemical examination of trace evidence in forensic
sciences - Part 2.Ultraviolet-visible absorption spectroscopy
GB/T 24370-2009 Nanotechnologies - Characterization of cadmium chalcogenide
colloidal quantum dot - UV-Vis absorption spectroscopy
GB/T 30544.1 Nanotechnologies - Vocabulary - Part 1.Core terms
JJG 178 Verification regulation of ultraviolet, visible, near-infrared
spectrophotometers
JJG 537 Verification regulation of fluorescence spectrophotometer
3 Terms and definitions
The terms and definitions as defined in GB/T 30544.1, as well as the following terms
and definitions, apply to this document.
3.1
Quantum dot nanocrystals
5 Instruments
5.1 UV-visible spectrophotometer
Select a UV-visible spectrophotometer that complies with JJG 178, which has a
wavelength range of 300 nm ~ 800 nm.
5.2 Fluorescence spectrophotometer
Fluorescence spectrophotometer is also called fluorescence spectrometer. Select a
fluorescence spectrophotometer that complies with JJG 537, which has an excitation
wavelength range of 250 nm ~ 700 nm and an emission wavelength range of 300 nm ~
950 nm.
5.3 Sample cell
A quartz sample cell with two or four sides transparent for spectral detection in the
ultraviolet and visible light regions, which has a 1 cm optical path.
Note. The sample cell can be selected according to GB/T 9721.
5.4 Instrument calibration
Depending on the instrument type, the detection instrument shall be verified/calibrated
according to JJG 178, JJG 537 or tested according to GB/T 19267.2.
6 Samples
6.1 Sample preparation
For the preparation method of cadmium selenide quantum dot nanocrystals, see
Appendix B of GB/T 24370-2009.Cadmium selenide quantum dot nanocrystals need
to be modified by specific surfactant molecules, before they can be uniformly dispersed
in the solvent as experimental samples for UV-visible absorption spectrum and
fluorescence emission spectrum detection. The surface ligands of cadmium selenide
quantum dot nanocrystals prepared by high-temperature oil phase pyrolysis are
aliphatic hydrocarbon molecules, which can be uniformly dispersed in non-polar
organic solvents such as n-hexane, toluene, dichloroethane.
6.2 Test sample requirements
The quantum dot samples to be measured shall be uniformly dispersed in a suitable
solvent, to form a clear and transparent sol.
7 Sample testing
7.1 UV-visible absorption spectrum
Use a UV-visible spectrophotometer to detect the UV-visible absorption spectrum of
the cadmium selenide quantum dot nanocrystal test sample 1). Mark 450 nm and the
band edge absorption peak wavelength (λabs) and the corresponding absorbance on the
measured UV-visible absorption spectrum line.
The absorbance of the test sample used to test the fluorescence emission spectrum at
the selected excitation wavelength shall be less than 0.05; the recommended absorbance
is between 0.03 and 0.05.
7.2 Fluorescence emission spectrum
7.2.1 Selection of fluorescence excitation wavelength
Use a fluorescence spectrophotometer to detect the fluorescence emission spectrum of
the test sample in 7.1.
When detecting the fluorescence emission spectrum, the excitation wavelength (λex) is
recommended to be selected as follows.
a) For quantum dot test samples intended for photoelectric conversion (especially in
the display field), select 450 nm as the excitation wavelength;
b) For test samples intended for biomedicine or other research or application fields,
any wavelength within the wavelength range of (λabs - 150, λabs - 30) nm can be
selected as the excitation wavelength; (λabs - 60) nm is recommended.
7.2.2 Test conditions
The following test conditions are recommended.
a) Fluorescence excitation wavelength (λex). λ nm;
b) Fluorescence emission wavelength (λem) range. (λ + 15, λ + 200) nm)2);
c) Slit width. 5 nm or 10 nm;
d) Temperature. 23 °C ± 2 °C.
7.2.3 Test steps
1 For test samples, test conditions, test steps, please refer to GB/T 24370-2009.
2 To avoid the influence of the double frequency peak, the maximum value of the fluorescence emission wavelength
range is usually less than 2 times the excitation wavelength.
d) Temperature. 23 °C ± 2 °C.
7.3.3 Test steps
The test steps for fluorescence excitation spectrum are as follows.
a) Add 2.5 mL of test sample to a quartz sample cell with four transparent sides;
cover it;
b) Place the sample cell in the sample slot; apply the instrument sample compartment
cover to ensure good sealing and opaqueness;
c) Set the emission wavelength, excitation wavelength range, slit width, scanning
speed and other parameters;
d) Start scanning to obtain the fluorescence excitation spectrum of the test sample;
e) Mark the fluorescence excitation wavelength on the fluorescence excitation
spectrum line.
For the detection example of cadmium selenide quantum dot fluorescence emission
spectrum, please refer to Appendix A. For the measurement of relative fluorescence
quantum yield of quantum dot nanocrystals, please refer to Appendix B.
8 Testing report
The testing report of quantum dot nanocrystal fluorescence emission spectrum shall
include the following.
a) Test sample.
1) Test sample name;
2) Solvent.
b) Test conditions.
1) Instrument model (UV-visible spectrophotometer, fluorescence
spectrophotometer);
2) Test parameters (sample cell, excitation wavelength, emission wavelength
range, slit width, testing temperature).
c) Test results.
1) UV-visible abs...