Advanced Material Characterizaion

We offer various advanced analytical services for characterization of materials including:

Powder X-ray Diffraction (XRD)

Qualitative and quantitative analysis of wide range of crystalline solid materials including minerals, clays, rocks, corrosion products, etc can be done using XRD. Powder diffraction allows for rapid, non-destructive analysis of multi-component mixtures without the need for extensive sample preparation. This gives us the ability to quickly analyze unknown materials and perform materials characterization in various fields such as metallurgy, mineralogy, forensic science, archeology, condensed matter physics, as well as biological and pharmaceutical sciences. Identification is performed by comparison of the diffraction pattern to a known standard or to a database such as the International Centre for Diffraction Data's Powder Diffraction File (PDF) or the Cambridge Structural Database (CSD).

Scanning Electron Microscopy (SEM) with EDX

SEM shows the topography of surface features at a few nm across. Materials are viewed at high magnifications up to 100,000x without the need for extensive sample preparation and without damaging the sample. Therefore sample morphology can be viewed in details. Backscattered Electron Imaging (EDX) shows the spatial distribution of elements or compounds within the top micron of the sample. Features as small as 10 nm are resolved and composition variations of as little as 0.2% can be determined.

Surface Area Measurement & Pore-Size Distribution Analysis

Surface area measurement is required for a number of different applications, particularlly where the materials surface is the key active part. Examples include: catalysts, the inner surface of hardened cement paste, activated carbon, and polishing compounds. Surface area is normally expressed in square meters per gram, and is the result of measuring surface roughness as well as quantity and size distribution of open pores. BET is a well known methode for the physical adsorption of gas molecules on a solid surface, and is the basis for an analysis technique for the measurement of the specific surface area of a material.

Carbon dioxide and Kr physisorption technique is used to determine the surface area and pore size of microporous solids. Other physosorption analysis using methane, ethane, hydrogen and Argon can be performed to give insight to other interesting chemical and physical properties.

Particle Size Measurements

Particle size affects many properties of materials such as strength, stability and flowability. Hence particle size measurement is an important feature in many industries. Particle size measurement can be done using:

Sieve Analysis: Ensemble method that looks at the entire distribution without looking at the individual particles.
Laser Diffraction: Particle counting method which looks at the size of many individual particles and then assume the distribution for the whole population.

Fourier-Transform Infra-red Spectroscopy (FTIR)

Fourier-transform infrared spectroscopy is widely used in both research and industry as a simple and reliable technique for qualitative or quantitative measurement, quality control and dynamic measurement. It is perhaps the most widely used spectroscopic method in industry. Infrared spectroscopy has been highly successful for applications in identification of organic and inorganic compounds. We can help you to analyse unknown solids and liquids.

Diffuse reflectance FTIR (DRIFT) allows us to do direct analysis of a powders or solid pieces. DRIFT can be used to study solids before and after a chemical reaction, surface treatments or corrosion studies.

Thermogravimetric Analysis (TGA)

TGA is a type of testing that is performed on samples to determine changes in weight upon changes in temperature. Such analysis relies on a high degree of precision in three measurements: weight, temperature, and the temperature change. TGA is commonly employed in research and industry to determine characteristics of various materials such as:

to determine degradation temperatures of polymers
absorbed moisture content of materials
amount of volatile inorganic and organic components in materials
decomposition points of various materials
solvent residues
to estimate the corrosion kinetics at high temperature

CATALYST CHARACTERIZATION VIA TEMPERATURE PROGRAMMED TECHNIQUES

Total Acidity or Basicity of Catalyst

Catalyst characterization via temperature programmed techniques is important to understand the nature of the active sites present in a catalyst. We have expertise to determine the total acidity or basicity of a catalyst using temperature programmed desorption method. Amonia or carbon dioxide are adsorbed on a surface to determine acidity or basicity respectively for a given solid. The amount of gas adsorbed can be quantified to determine the extent of chemisorption.

Peak of desorbed amonia at low and high temperatures is indicative of the weak and strong acidic sites respectively. Applications include: heterogeneous catalysis for petroleum refining, carbon dioxide adsorption, solids for NOx and Sulfur removal etc.

Temperature Programed Reduction

Temperature programmed reduction using hydrogen is carried out to understand the nature of reducing species in a given solid. It is used to characterize metal oxides, mixed metal oxides and metal oxides dispersed on a solid. This characterization method allows us to determine the temperature at which a metal in a solid gets reduced.

The following figure shows that there are two kinds of metallic species in a given solid that tend to reduce at different temperatures. One around 550 °C and the other around 870 °C. So if a catalytic reaction involving hydrogen is carried out around 600 °C, only one kind of metallic species would do the catalysis. The high temperature metallic site shall remain catalytically inactive. This information is important for catalyst characterization in refining industry.

Dynamic Light Scattering (DLS)

We offer to determine particle size of nano particles via dynamic light scattering method. A given nano particle is suspended in oil or water phase. The amount of light scattered is propotional to the size of the particles. Application includes proteins, polymers, micelles, carbohydrates, nanoparticles, colloidal dispersions, emulsions, microemulsions.

Number, volume and intensity distributions of a bimodal mixture of 5 and 50nm lattices present in equal numbers are shown here as an example (www.malvern.de).

We are utilizing a Zetasizer Nano from Malvern instruments for dynamic light scattering measurements.

UV-Vis Spectroscopy

UV-vis spectroscopy can be used for a variety of applications such as quantitative and qualitative analysis organic and inorganic compounds with active chromophore usually a functional group. It can also be used to study the kinetics of adsorption or a chemical reaction.