Dynamic vapor sorption analyzers
Water sorption behavior plays an important role in the development and use of many common and advanced materials. Some examples include:
► Stability of pharmaceutical excipients and drug actives.
► Drying and storage of grains.
► Texture and shelf life of food products .
► PEM fuel cell components.
► Mortar, grout and other cementitious materials.
► Paper and coatings.
► Hydrophobic surface treatments.
► Microporous and nanostructured carbons.
► Archaeological ceramics .
The Aquadyne DVS instruments are fully automated, gravimetric, one or two sample water vapor sorption analyzers. They measure adsorption and desorption isotherms of water vapor both accurately and sensitively, including sorption kinetics, with minimal operator involvement. The weight(s) of one or two sample(s) is / are constantly monitored and recorded as the relative humidity is automatically varied by the blending of dry carrier gas with a saturated gas stream using precision mass flow controllers.
The dual balance design of the Aquadyne DVS-2HT allows increased analysis throughput, side-by-side comparison with known or reference materials, or an extended mass range for a single sample.
The independently temperature controlled balance head environment ensures long term stability. The small sample chamber ensures rapid changes in sample atmosphere conditions when the relative humidity is altered during an analysis. Sample(s) can be pre-dried insitu up to 90° C (DVS-2HT) in a flow of dry gas. A version of the software which fully supports 21 CFR Part 11 is available to ensure and document the integrity of the data. The software runs under Windows 7 or higher.
Measurement Capabilities
Isotherms:
Mass change as a function of changing relative humidity, increasing mass during adsorption (increasing RH%), decreasing mass during subsequent desorption (decreasing RH%).
Kinetics:
Time-dependent studies give the rate of sorption.
Effect of Temperature:
Isotherms and kinetics change as a function of temperature. Can be used to yield sorption enthalpies.
Applications/Results DVS-1/DVS-2HT3
Deliquescence:
Certain salts exhibit the property of dissolving in selfadsorbed water.
Equilibrium moisture content:
Quantitatively the amount of water associated (adsorbed/absorbed) with the material under given atmospheric conditions of temperature and relative humidity (organic materials may be subject to molding according to atmospheric humidity, for example).
Hysteresis working range:
Adsorption and desorption usually differ by hysteresis - this gives a range of stability in which subsequent sorption cycles produce no change in equilibrium moisture content.
Hydrophobicity/philicity:
The shape of the isotherm reveals relative strength of affinity between water and the surface, due to polar or other chemical interactions.
Micropore investigations:
Even hydrophobic materials can take up moisture if their pores are small enough.
Crystallization phenomena:
Certain amorphous materials will undergo crystallization as a function of water sorption due to, for example, shifts in glass transition points.
Sample form:
Sorption kinetics can be altered by the physical form of a material - powder, granule, pellet, tablet, monolith etc.
The one-station Aquadyne DVS-1 offers a weighing resolution of 0.1 µg and an analysis temperature range of 15°C to 60°C. Aquadyne DVS-2HT offers increased throughput with a second analysis station, a broader temperature range of 10°C to 85°C, and the unique ability to combine stations for a maximum sample weight of 10 g.
| Model | Aquadyne DVS |
| Balance heads | 1 (DVS-1), 2 (DVS-2HT) |
| Balance type | Ultrasensitive electronic microbalance |
| Balance capacity | 5 g per balance head |
| | 10 g combined (DVS-2HT only) |
| Dynamic weighing range | ±500 mg, 0 mg to 1000 mg (per station) |
| | ±1000 mg, 0 mg to 2000 mg combined (DVS-2HT only) |
| Weighing resolution | 0.1 µg |
| RH range | <2 % to 98 % (depending on temperature) |
| RH resolution | 0.1 % |
| RH accuracy | ±0.8 % RH at 25 °C |
| Sample chamber temperature | 15 °C to 60 °C (DVS-1) |
| range | 10 °C to 85 °C (DVS-2HT) |
| Sample chamber temperature stability | ±0.1 °C |
| Gas flow rates | 0 cm³/min to 200 cm³/min (mass flow controllers) |
| Viewing port/sample chamber | Heated, triple-glazed |
| door | |
| Data acquisition rate | Adjustable, up to 12 points per minute |
| Sample pan material | Silica |
| Water reservoir capacity | 46 mL |
| |
Brochure_ParticleCharacterization.pdf
To get information about: «Aquadyne DVS» contact us by phone (044) 229 15 31 or fill in the form.