Chemistry & Physics of Materials
Southern Research Institute has developed a number of unique facilities and procedures dealing with specific problems encountered in the applications of structural, insulative and ablative materials. Engineers and chemists in the Chemistry and Physics of Materials laboratory have extensive experience characterizing materials and understanding their behavior in a variety of applications, focusing on:
Contact:
Eric H. Stokes, PE
Research Engineer
205-581-2649
stokes@sri.org
Material Chemistry
- Moisture specific weight loss
- Moisture absorptivity
- Total carbon analysis
- Oxidative mass loss from oxygen adsorbing materials
- Kinetic of decomposition and gasification
- Thermogravimetric weight changes at heating rates up to 3000°C/minute
- Combined thermogravimetry / mass spectroscopy
Material Physics
- Constituent mass and volume fractions in cured polymer based composites
- Swelling
- Total and apparent porosity
- Pore size distribution
- Gas compressibility
- Effective porosity
- Complex permittivity
- Complex permeability
- Dielectric loss tangent
- Refractive index and phase
- Conductivity
Mass Transport Characteristics
- Moisture and solvent diffusion
- Molecular diffusion through membranes
- Gas permeability of consolidated and unconsolidated media
- Cryogenic to 2760°C (5000°F)
- Capabilities to 6000 psid
- Over 16 orders of magnitude in permeability
- Flow regime determination
- As a function of material direction
- Simultaneous multi-axial flow measurements
- Contiguous pore path characterization
- Pore evolution as a function of environmental history
- Permeability and diffusion of inert and reactive gases (hydrogen, methane, oxygen, etc.)
- Gas permeability as a function of combined applied multi-axial mechanical stress/strain and temperature
Dielectric Characterization Facility
Southern Research Institute's Chemistry and Physics of Materials Group has a facility measuring the dielectric properties of materials. The facility is capable of measuring nine electric and magnetic properties of materials including real and imaginary permittivity, real and imaginary permeability, permittivity and permeability loss tangent, refractive index and phase, and conductivity. Materials can be evaluated at elevated temperature and pressures from ambient to vacuum. Institute personnel are currently working to extend the operating envelope of the instrument in both pressure and frequency dimensions.
- Real and imaginary permittivity
- Real and imaginary permeability
- Permittivity and permeability loss tangent
- Refractive index and phase
- Conductivity
- Solid, fabric and surface measurements
- Room temperature 45 - 9000 MHz
- Elevated temperature to 1000°C (1800°F)
- Vacuum (0-14.7 Psi)
- Variety of gases
Complex Permittivity and Loss Tangent
Complex Permeability and Loss Tangent
Room Temperature Capabilities – Frequency
| Solid Samples |
<14 mm diameter |
45-9000 MHz |
| Solid Samples |
14-50mm diameter |
45-2000 MHz |
| Surface Samples |
>50mm diameter |
45-2000 MHz |
| Surface Samples |
25-50mm diameter |
45-4000 MHz |
| Fabric Samples |
<50mm diameter |
45-2500 MHz |
Sample Types and Sizes
- Solid
- Fabric
- Surface
- Up to 50mm diameter
Elevated Temperature Capabilities
- Temperature: 20-1000°C (70-1800°F)
- Pressure: vacuum – 101 kPa (0-14.7 psi)
- Variety of gases
- Frequency: 3300 to 4900 MHz
Contact:
Eric Stokes, PE
205-581-2649
stokes@sri.org
In addition, facilities have been developed which are capable of reproducing and studying the pore pressure induced delamination and plylift failure events of composite materials under a variety of controlled conditions.
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