microporebetSpecific surface area analyzer

JW-BK200CResearch grade ultra-high performance dual station specific surface area and microporous porosity analyzer, fully inheritingJWAll technical features of the series aperture analyzer are independently and uniquely innovated. The core hardware of this instrument is all made of international advanced brands and equipped with“Turbo Molecular Pump”reach1torrThe small range pressure sensor, combined with the accurate application of the microporous analysis model, fully realizes the precise analysis of micropores and nitrogen adsorption micropores Small aperture can actually be measured0.35nmThe accuracy, precision, and stability of the test results have fully reached the level of similar imported instruments, and the cost-effectiveness is extremely high. It is very suitable for activated carbon, activated alumina, molecular sieves, zeolites, etcMOFMaterials, etc.

microporebetPerformance parameters of specific surface area analyzer:

Instrument model:JW-BK200CmicroporebetSpecific surface area analyzer

Principle and method: static capacity method, low-temperature nitrogen adsorption;

Test function: isothermal adsorption desorption curve; Single point, multi-pointBETSpecific surface area;LangmuirSpecific surface area; External surface area（STSA）； Adsorption total pore volume and average pore size;BJHAnalysis of mesoporous macropore volume and pore size distribution;t-plotLawα s- plotLawDRLawMPConventional analysis of micropores;HKLawSFAccurate analysis of micropores;NLDFTAnalysis of aperture distribution using the method; True density test; Gas adsorption capacity and adsorption heat testing; Quality input method testing;

Test gases: nitrogen, oxygen, hydrogen, argon, krypton, carbon dioxide, methane, etc;

Test scope: Specific surface area0.0005m2/gUp to no limit, aperture3.5 nm-5000 nm；

Scope of pore volume testing: 0.0001cc/gUp to no limit;

Repeatability accuracy: specific surface area≤± 1.0%, aperture≤0.2 nm；

Test efficiency: Average specific surface area per sample15minAverage analysis of mesoporous and macroporous samples per sample2-3Hour; Micropore analysis average per sample5-8Hour;

Analysis Station:2A completely independent microporous analysis station, with dual stations capable of conducting testing simultaneously;

P0Position:2A completely independent individualP0Station;

Lifting system:2A sample analysis station is set up in situ2Set up an independent lifting system, electrically controlled and automatically controlled, and do not interfere with each other;

Vacuum system: Multi channel parallel vacuum pumping system, modular modular design, vacuum pumping speed fine adjustment valve system * * technology, can be used in2-200ml/sAutomatic adjustment within the range;

Vacuum pump: External imported two-stage rotary vane mechanical vacuum pump (automatic oil backflow prevention)+Built in imported turbo molecular pump, with a maximum vacuum degree of up to10^-6Pa；

Degassing system: Standardized design of same position and out of position vacuum degassing pretreatment system, controlled by separate inlet pressure sensors, completely separated from the analysis position, can measure the vacuum degree of the degassing system in real time and accurately:2An independent heating package,2A set of independent temperature controllers, both capable of programmable temperature control, with up to several heating steps10Stage can be used for both in-situ degassing and ex situ degassing of samples;2At the same time as analyzing and testing one sample, vacuum degassing treatment can be performed on the other two samples;

Degassing temperature: room temperature—400℃, accuracy±1℃；

Pressure sensor: imported with original packaging,1000torr、10torr、1torr, accuracy≤± 0.15%(Read value);

Voltage division range:P/P0 10^-8 - 0.998；

Pressure control: Balanced pressure intelligent control method, pressure controllable interval<0.1KPa, adsorption High pressure points can be automatically controlled;

Data collection: Ethernet data collection, fast collection speed, high accuracy, compatibleWindows 7/XP 32/64Positional system;

microporebetTechnical characteristics of specific surface area analyzer:

●Fully independent dual station parallel analysis, capable of simultaneously conducting pore size analysis and degassing treatment of two samples, with high testing efficiency;
●The instrument is equipped with two ectopic degassing stations, and the analysis station also has the function of in-situ degassing, with a humanized design; High degassing temperature400℃；
●Dual station multi-pointBETCompared to surface testing,30It can be automatically completed within minutes;
●Adopting a liquid nitrogen surface control comprehensive system and software compensation technology to ensure a relatively constant non-uniform temperature field in the sample chamber throughout the entire testing process, in order to ensure the accuracy of analysis, suitable for various cold baths such as liquid nitrogen, liquid argon, ice water, etc;
●Introducing advanced temperature control clamp technology from abroad, equipped with3LLarge capacity vacuum glass inner Dewar flask and anti liquid nitrogen evaporation unit ensure the sustainability of the experiment72Hour;
●Self controlled adjustable multi-channel parallel vacuum pumping system, built-in anti splash unit, and“STEP CUT”Anti splash program, effectively preventing ultrafine powder from flying and completely avoiding instrument contamination;
●The original imported turbo molecular pump and the original imported mechanical vacuum pump are used together, and the maximum pressure of the analysis station and degassing station can reach up to10-8Completely satisfied0.35nm-0.7nmUltra microporous analysis;
●imported with original packaging1000torr、10torr、1torr(Can be upgraded to)0.1torr）The combined use of three pressure sensors with different ranges results in high precision and small errors in pressure data acquisition, fully meeting the requirements for precise analysis of micropores;
●Nitrogen saturation vapor pressure during mesoporous and microporous experimentsP0Fully real-time testing, conducted in parallel with the analysis station; At the same time, atmospheric pressure input method can be used for measurementP0；
●The sample degassing system is equipped with a cold trap device, which can effectively remove impurities such as water and harmful substances that may be emitted during sample degassing, avoiding contamination of the vacuum system;
●The instrument control panel is equipped with valve position control indicator lights, allowing experimenters to more intuitively and clearly see the working status of the control valve, with a user-friendly design;
●Non local density function theoryNLDFTAnalyze the standard configuration of the model to achieve international standards;
●HK、SFAccurate application of microporous analysis model and domestic microporous analysis technology A company that has passed the metrological certification of China National Institute of Metrology;
●Balanced pressure intelligent control technology, sample suction/The automatic determination and data collection of desorption equilibrium pressure, as well as the control accuracy of isothermal adsorption desorption curve measurement, have reached international standards;
●Ethernet data acquisition and processing software, guided operation, one set of software can control multiple instruments simultaneously, and can be remotely controlled;

microporebetApplication areas of specific surface area analyzer:

●Catalyst materials: activated alumina, molecular sieve, zeolite, etc;
●Environmental protection field: adsorbents such as activated carbon;
●Nanomaterials: Nanoceramic powders (alumina, zirconia, yttrium oxide, silicon nitride, etc.) Silicon carbide, nano metal powders (silver powder, iron powder, copper powder, tungsten powder, nickel powder, etc.) Nano polymer materials, carbon nanotubes, etc;
●Coal mining industry: coal, ore, rock, shale gas, coalbed methane, etc;
●Other materials: ultrafine fibers, porous fabrics, composite materials, etc.

microporebetTechnical tips for specific surface area analyzer:

Introduction to Practical Techniques for Specific Surface Area Analysis:

There are several factors that have a significant impact on the testing process and results of gas adsorption method, such as surface area and pore size distribution (porosity). Effective analysis of test results requires consideration of these factors. These factors include: sample processing conditions, characteristics of adsorbate gases, different testing methods, etc., which will be described in detail below.

　　Sample processing conditions

Due to the close relationship between the determination of specific surface area and porosity and the outer surface of particles, and the key to adsorption method determination is the adsorbate gas molecules“effectively”Adsorbed on the surface of the tested particles or filled in the pores, therefore, whether the surface of the sample particles is“clean”crucial. The main purpose of sample processing is to release the surface occupied by non adsorbate molecules as much as possible, in order to facilitate the surface adsorption of adsorbate molecules during the testing process. Generally, pre-treatment is required before sample determination, and the treatment method is selected according to the characteristics of the measured sample. In general, most samples need to remove the water molecules adsorbed on their surface, so it is higher than100℃ (usually taken as105℃-120Drying at normal pressure (℃) can achieve this goal, which is beneficial for simplifying the operation process. For samples containing micropores or with strong adsorption characteristics, impurity molecules are easily adsorbed at room temperature and pressure, or many other molecules are adsorbed on the surface during the manufacturing process. It is usually necessary to perform degassing treatment under vacuum conditions, and sometimes an inert protective atmosphere must be introduced during the pretreatment process to facilitate the desorption of impurities on the sample surface. In summary, the purpose of sample pretreatment is to make the surface of the sample clean, in order to ensure accurate and effective measurement results of specific surface area and pore size (porosity).

　　Characteristics of adsorbate gas

In the analysis and testing of surface area and pore size distribution of gas adsorption method, the adsorption of adsorbate gas The basic requirement is that its chemical properties are stable, and the adsorption process will not have any impact on the performance and surface adsorption characteristics of the sample itself, and it must be reversible physical adsorption. Nitrogen is The commonly used adsorbate, practice has shown that nitrogen is chosen as the adsorbate for the determination of the vast majority of substances, and the accuracy and repeatability of the test results are ideal. For samples containing micropores, if the micropore size is very small, close to the diameter of nitrogen molecules, on the one hand, nitrogen molecules are difficult or impossible to enter the micropores, resulting in incomplete adsorption; On the other hand, the adsorption characteristics of gas molecules in pores with diameters equivalent to their own are very complex and are influenced by many additional factors, so the adsorption capacity cannot fully reflect the size of the sample surface area. For such samples, argon or krypton with smaller molecular diameters are generally used as adsorbents to facilitate sample adsorption and ensure the validity of test results.

　　Testing method factors

Different testing methods also have a significant impact on the test results, and each testing method has its own advantages and disadvantages. In the continuous flow method, due to the use of“contrast”The principle of the method can effectively reduce the impact of sample processing on test results compared to the capacity method. By comparing, to some extent, the errors caused by imperfect processing between the standard sample and the tested sample can be offset, provided that the surface structure and adsorption characteristics of the two samples are similar and the processing conditions are the same. This is very valuable for testing used for on-site product quality control purposes, reducing sample processing time and greatly improving testing efficiency. If the same substance is used as the standard sample and the tested sample, due to the similar surface structure and adsorption characteristics, the specific surface area test result will be insensitive to the sample processing conditions, in other words, the error will be offset. Therefore, the continuous flow method is very suitable for on-site inspection of product quality. On the contrary, the capacity method can be said to be very sensitive to sample processing because it uses The principle of measuring adsorption capacity is that any unclean surface or other factors that affect the adsorption process of adsorbates will directly affect the measured product.