GOLD APP INSTRUMENTS analyzing services is equipped with the latest and most powerful analytical instruments for the physical characterization of materials. Including single and multi- point BET surface area, full pore size, pore area and pore volume determination, true density measurements and Gibbs adsorption isotherms by high pressure and high temperature. Our techniques may be combined and the analysis tailored to suit our customers’ specific materials and individual requirements.

The state-of-the-art analytical software used at GOLD APP INSTRUMENTS is extremely powerful in terms of the reporting options available. For this reason we offer standard reporting formats which include the most commonly required information. It is, however, possible to expand these to include very specialised report formats.

We can also generate graphical plots showing overlaid sample information according to individual specifications of parameters. These are supplied in a file format suitable for direct application to written reports, presentations and publications. Furthermore, raw data can often be supplied in an Excel file.

If you have any further questions about our services or would like to discuss sample analysis or a collaborative research project then please contact us via email sales@goldapp.com.cn

 Analyzing List

The testing data obtained from our analytical tests are generally reported in a standard format, giving a great depth of information yet in an easily understandable and locatable manner and are transferred as pdf files for speedy communication. However, the software used at GOLD APP INSTRUMENTS is state-of-the-art and our measurement data reports can be expanded to include additional information pertinent to individual requirements. 

All analytical equipments at GOLD APP INSTRUMENTS are regularly checked using approved reference materials, ensuring that our customers gain both accurate and reliable results. This makes our analytical tests appropriate for both QC work and fundamental research.

BET Surface Area testing service

BET Surface area measurement, also termed specific surface area (SSA), is undertaken through two fundamentally different techniques, static volumetric or flowing gas technique. In both cases either a single point BET measurement or, more accurately, multipoint BET measurement is available. Through this, and the availability of a wide choice of adsorbent gases, the surface area of almost any solid, powder, porous, fiber etc sample can be determined, such as activated carbon, silica gel, active alumina oxide, molecular sieve, sepiolite, zeolite, alumina oxide, zirconium oxide, black lead, ferrite, nano metal materials, filler, silica, inorganic powders, rare earth, coal, cement, catalyst, cleansing agent, filter aid, superfine fiber, porous fabric, composite material and so on.

For the determination of very low surface areas (typically lower than about 0.1 m2g) the use of krypton gas in place of nitrogen as the absorptive provides for increasing accuracy.

Comprehensive actions of pretreatment options are available and analytical parameters are fully flexible to allow accordance with pre-existing specifications. 

The standard report data with the surface area measurement and the BET surface area plot. The determination of surface area also forms part of our standard report for gas adsorption isotherm data.

GOLD APP INSTRUMENTS testing is able to offer extensions to traditional surface area measurement, thus covering the most specialized analyses, through the application of alternative adsorbate gases, such as krypton, argon and carbon dioxide. As with our standard testing, these methods also employ the BET area method and Langmuir surface method.

Micropore analysis

GOLD APP INSTRUMENTS offers dedicated micropore analysis using the volumetric technique micropore instruments (V-Sorb 2800, V-Sorb 2800P, V-Sorb 2800TP, V-Sorb 4800P, V-Sorb 4800TP), capable of obtaining adsorption/physisorption data at ultra-low partial pressures.  Analysis of the isotherm may be confined to the micropore range of pressures or extended to measure a full isotherm thus providing micropore and mesopore distribution data. Micropore reports detail both micropore volume and area together with the surface area of the material.

GOLD APP INSTRUMENTS micropore physisorption instruments extend the range of pore sizes analyzed down to approximately 0.35 nm diameter. The common data reduction techniques are available for the generation of micropore volume and micropore area reports and the most appropriate may be selected according the specific material being analyzed and its application.       

The combination of the adsorptive used and reporting options selected, allow analyses to be tailored to the most specialised of applications. For example, the Saito Foley cylindrical pore volume can be generated from Horvath Kawazoe data, which is particularly suited to the analysis of zeolites and MOFs. Of particular interest to hydrogen storage / fuel cell materials is the generation of pressure composition isotherms showing hydrogen adsorption capacity. Carbon dioxide adsorption can also be undertaken at common temperatures.  

If have any particular questions or technique problems, please find us at any time, GOLD APP INSTRUMENTS staffs will be glad to discuss your requirements and provide sample testing data reports pertinent to individual applications.

Density analysis

Helium Pycnometry (helium density, true density / absolute density)

The measurement of sample density by pycnometry is undertaken at GOLD APP INSTRUMENTS through gas pycnometer helium true density analyser G-DenPyc X900 series,  it providing fundamentally different information regarding sample density.

Helium pycnometry is applied to the measurement of the absolute density of a sample (also termed the true density or helium displacement density). This technique may be combined for the measurement of the total pore volume of a sample. This is performed using a state-of-the-art G-DenPyc 2900 porosimeter which has 3 stations and has a sound sealing performance can guarantee a thermostatic analysis environment and highly accurate and reliable density measurements data produced. A variety of sample cells of differing volume are available to accommodate a wide range of sample types and sizes.

Pore size analysis

Pore sizes, pore size distribution and porosity are usually quoted in the terms of micropore, mesopore and macropore ranges. 

The most common techniques for porosimetry analysis are Mercury Porosimetry (covering the meso pore and macro pore ranges) and Gas Adsorption Isotherms (for the micro pore and meso pore range). Dedicated micropore analysis is provided for the smallest pore sizes and we offer a range of adsorptive gases to meet with the most specialized of analyses. 

Information on these techniques and our analytical services is given below. The table below provides a guide for the categorization of pore sizes. 

Classifications of pore size distribution

*These ranges refer to the diameter of a cylindrical pore or the width of a slit-shaped pore. 

No single porosimetry technique can determine pore size distribution, pore volume or the porosity of a sample throughout the entire range of pore sizes. 

GOLD APP INSTRUMENTS Services offers gas adsorption / isotherm techniques for the determination of the pore size distribution, pore area and pore volume distribution and the measurement of sample porosity. The choice of technique is dependent on the expected pore sizes within the sample.

For the analysis of mesoporous materials, gas adsorption (adsorption isotherms) using our V-Sorb 2800TP is recommended. The pore size range covered by this technique is typically 2 nm to 50 nm but can be extended depending on the nature of the sample. 

Gas Adsorption and Desorption Isotherms

Porosimetry by gas adsorption / desorption. 

Pore size distribution, pore volume distribution and pore area distribution

Full gas adsorption / desorption isotherms are provided by GOLD APP INSTRUMENTS Services using a state-of-the-art instrument. These are conducted using nitrogen gas, alternative adsorptive gases being available via our micropore analysis options. 

This technique provides a full porosimetry testing method through  pore size distribution, pore area and pore volume data. These are  reported as standard with this analysis together with the multipoint BET surface area of the sample. Typically pore sizes in the range 0.55 nm to 350 nm diameter are measured by this technique, although this may be extended to larger pore sizes depending on the nature of the sample. The test is ideal for the characterisation of microporous and mesoporous materials and may be combined further with mercury porosimetry to cover the complete range of micro pores through to macro pores at approximately 600 μm. Generation of adsorption data at very low partial pressures has proven beneficial to the assessment of microporous materials rapid determination is required. 

GOLD APP INSTRUMENTS Services has considerable expertise in the field of porosimetry and gas adsorption isotherms and we often work alongside our clients on specialised projects. If these activities are of interest, then please contact our staff who will be happy to advise and discuss the options available. We offer assistance with interpretation of results at no extra charge, ensuring that our clients obtain the maximum information from the analysis.

 
GOLD APP INSTRUMENTS Services provides clients with a broad range of data as standard for this technique, including:  

• Graphical gas isotherm plot for adsorption and desorption
• Multi point BET surface area plot
• Multi point BET surface area data
• Tabulated gas adsorption and desorption data (including pore size, pore area and pore volume distribution)
• Cumulative pore area / pore size distribution (graphical and tabulated)
• Differential pore area / pore size distribution (graphical and tabulated)
• Cumulative pore volume / pore size distribution (graphical and tabulated)
• Differential pore volume / pore size distribution (graphical and tabulated)

For more specialised porosimetry testing, alternative reports and data analyses can also be included on request, for example t-plots and other associated representations. Data may be derived from the adsorption isotherm or desorption isotherm depending on preference.       

For the generation of accurate pore size distribution, pore volume and pore area data it is imperative that samples are degassed prior to analysis. GOLD APP INSTRUMENTS Services can accommodate a wide range of conditions for this which may be combined to suit the individual requirements of our clients. Degassing temperatures up to 200˚C under vacuum or 400˚C with flowing nitrogen or helium gas can be applied. This is usually conducted at GOLD APP INSTRUMENTS Services immediately prior to analysis as part of  standard procedure.

A standard specimen report for the full analysis of sample porosity through gas adsorption is available in PDF format, Please contact GOLD APP INSTRUMENTS Services for a copy.