Abstract: The barrier properties of graphene to gases are one of the research directions. In this paper, helium gas is used as the permeating gas, and the barrier property of graphene sample to helium gas is tested by differential pressure gas permeation instrument. The experimental principle, equipment parameters, application range and test procedure are introduced to study and test graphene. Or other materials provide reference for the barrier properties of oxygen, nitrogen, carbon dioxide, sulfur hexafluoride, helium and other gases. Key words: helium gas permeation, differential pressure gas permeation instrument, graphene, gas permeability, barrier properties 1 , meaning As a new emerging material in recent years, graphene has excellent optical, electrical and mechanical properties, and has broad application prospects in electronics, optics, magnetism, biomedicine, catalysis, energy storage and sensors. The dense internal structure determines the excellent barrier properties of graphene. How to use or change the barrier properties is an important research direction of graphene, such as graphene gas barrier film and high permeability graphene filter membrane. Helium is the inert gas with the smallest molecular diameter. It is widely used in aerospace, medical, optoelectronics production and other industries, as well as in the preparation of graphene products and gas permeability studies. In this paper, an effective graphene gas barrier performance detection technique is introduced by taking the test procedure of graphene gas transmission. 2 , test samples In this paper, a graphene film provided by a research institute is used as a test sample. 3 , test methods The test method for gas permeability of film materials is mainly divided into two principles: differential pressure method and equal pressure method. The differential pressure method can test more kinds of gases, and the equal pressure method can only be used for oxygen permeability test. Therefore, this test Refer to the test using the differential pressure method. The test is based on GB/T 1038-2000 " Phase Difference Method for Plastic Film and Sheet Gas Permeability Test Method ". 4 , test equipment In this paper, the VAC-V2 differential pressure gas permeation instrument is used to test the helium gas permeation of the sample. The equipment is independently developed and produced by Jinan Languang Electromechanical Technology Co., Ltd. Figure 1 VAC-V2 differential pressure gas permeation meter 4.1 Test principle The principle of the differential pressure method is to obtain the gas permeation amount of the material by monitoring the change of the gas pressure in the low pressure chamber of the pressure sensor. The clamped sample divides the test chamber of the device into upper and lower test chambers. The upper chamber is filled with test gas. In this paper, helium gas is formed, and the lower chamber is vacuumed to form a low pressure environment. At the beginning of infiltration, the helium gas in the upper chamber penetrates the sample from the upper chamber into the lower chamber under the action of the pressure difference, causing the change of the gas pressure in the lower chamber. The pressure sensor in the lower chamber monitors the pressure in the lower chamber in real time with the penetration time. The change of the situation, and based on this, the helium gas permeation amount of the sample was obtained. 4.2 Scope of application (1) This equipment is specially used for testing the gas permeability, permeability coefficient, solubility coefficient and diffusion coefficient of various film and sheet samples at various temperatures. (2) This equipment can also be extended to aerospace materials, paper and paperboard, paint film, fiberglass cloth, glass fiber paper, cosmetic hose sheets, various rubber sheets and other materials for gas permeability testing. (3) This equipment is suitable for the permeability test of various gases, such as oxygen, carbon dioxide, nitrogen, helium, air, etc. (4) This equipment can meet a variety of national and international standards, such as ISO 15105-1 , ISO 2556 , GB/T 1038 , ASTM D1434 , JIS K7126-1 , YBB00082003 and so on. 4.3 Equipment parameters The test range of the equipment is 0.05 ~ 50,000 cm 3 /(m 2 ·24h·0.1MPa) , the vacuum resolution can reach 0.1 Pa ; the temperature control range is 5 °C ~ 95 °C , the temperature control accuracy is ±0.1 °C ; the humidity control range It is 0%RH , 2%RH ~ 98.5%RH , 100%RH , and the humidity control precision is ±1%RH , which can meet the testing requirements of customers under different test conditions. There are three completely independent test chambers, which can test three kinds at the same time. The same or different samples; can be fitted to the data at any temperature, easy to obtain the test results under extreme test conditions; can also support the test of toxic gases, flammable and explosive gases after the modification; provide standard film for rapid Calibration to ensure the accuracy and versatility of the test data; support Lystem TM laboratory data sharing system, unified management of test results and test reports. 5 , the test process (1) Cutting samples Three samples having a diameter of 97 mm were cut out from the surface of the graphene film sample. (2) The sample is applied with a layer of vacuum grease around the three test chambers, and then a 65 mm diameter filter paper is placed in the test area in the middle of each test chamber to support the sample and prevent the low pressure chamber. Being polluted. Finally, the sample is flattened onto the test chamber, the upper chamber is closed and tightened. (3) Connect the helium to the test equipment, set the sample name, thickness, test temperature, test humidity and other parameters on the control software. Click the test start option to open the vacuum pump and the test starts. (4) End of test The equipment automatically completes the upper chamber inflation - lower chamber vacuum - upper and lower chamber vacuum - upper chamber inflation - test infiltration process according to the set parameters . After the test, the equipment displays the test results. 6 , test results The test results of the three samples tested in this test were 1.0113 cm 3 /(m 2 ·24h·0.1MPa) , 1.1848 cm 3 /(m 2 ·24h·0.1MPa) , 1.2007 cm 3 /(m 2 · 24h · 0.1MPa), graphene samples helium permeation rate of the average of three test specimens results 1.1323 cm 3 / (m 2 · 24h · 0.1MPa). 7 , conclusion In this paper, through the test of the helium gas permeation of graphene samples, the detection technology of the gas barrier properties of graphene materials by the principle of differential pressure method is introduced. The equipment is simple in operation, high in intelligence, and reduces the man-made operation process; the test result has high precision and good accuracy, and can truly reflect the barrier performance of the tested graphene sample on helium gas. Labthink is a high-tech enterprise specializing in the production of R&D packaging testing equipment and providing efficient and reliable packaging testing services. Over the years , it has provided tens of thousands of oxygen barrier testing equipment and services to customers around the world . Labthink is looking forward to enhancing technical exchanges and cooperation with enterprises and institutions in the industry. Vault Room Construction,Vault Room In House,Vault Room Door,Vault Room Hebei Yingbo Safe Boxes Co.,Ltd , https://www.yingbosafes.com