Posts by Nanbiosis

U6-E16. Freeze Dryer

Freeze drying (also known as lyophilization) is a water (or other solvents) removal process typically used to preserve materials, to extend their shelf life or reduce its weight. Freeze drying works by freezing the material, then reducing the pressure and adding heat to allow the frozen water in the material to change directly to a vapor (sublimation).

Freeze drying occurs in three phases:

             1-Freezing

Freezing can be done in a freezer, a chilled bath (shell freezer) or on a shelf in the freeze dryer. Cooling the material below its triple point ensures that sublimation, rather than melting, will occur. This preserves its physical form.

              2-Primary Drying

Freeze drying’s second phase is primary drying (sublimation), in which the pressure is lowered and heat is added to the material in order for the water to sublimate. About 95% of the water in the material is removed in this phase. Primary drying can be a slow process.

             3-Secondary Drying

Freeze drying’s final phase is secondary drying (adsorption), during which the ionically-bound water molecules are removed. Most materials can be dried to 1-5% residual moisture.

Technical Specifications:

• Vacuum pump: 7 m³/h
• Condenser min. Temperature: – 80º C

Aplications:

Solvent removal is typically used to preserve materials, to extend their shelf life or reduce its weight.

U6-E05. Tangential flow filtration system

Tangential flow filtration (TFF)  is a process of separation widely used in bio-pharmaceutical and food industries. It is different from other filtration systems in that the fluid is passed parallel to the filter, rather than being pushed through a membrane perpendicularly which can clog the filter media. This method is preferred for its continuous filtration and reproducible performance. The particles that pass through the membrane, the permeate, are put off to the side, while the rest, the retentate, is recycled back to the feed.

 Technical Specifications:

• Volume: 10 ml
• Filtration volume rate: 0.01 to 2300 ml/min

Aplications: Tangential flow filtration is used in the following processes:

Concentration: Increases the concentration of a solution by removing fluids while keeping the solute molecules. This process is done by selecting a filter significantly smaller than the solute molecules to allow for a higher retention of solute molecules.

 Diafiltration:  The separation of small and large particles, leaving the smaller particles behind without altering the overall concentration.

U6-E08. Mastersizer 2000

Mastersizer 2000 – Malvern

Description:

The Mastersizer 2000 uses the laser diffraction technique to measure the size and particle size distribution of materials. This is carried out by measuring the intensity of light scattered when a laser beam passes through a sample of dispersed particles. The detectors measure light intensity for red and blue light. The data is analyzed to calculate the size of the particles that created the scattering pattern.

The equipment contains two sample dispersion units:
– Wet: for samples in solution, which can be applicable to different solvents.
– Dry: for solid samples in powder form, which are dispersed by a current of air.

Technical specifications:

• Particle size: 10 nm – 3.5 mm
• Measurement principle: Mie and Fraunhofer dispersion
• Light source:
– Red: He-Ne (632.8 nm)
– Blue: LED (470 nm)
• Optical Alignment: Automatic rapid alignment system with darkfield optical reticle and multi-element alignment detector
• Dispersion units:
– Dry route
– Wet route
• Operating temperature: 5º to 40º C

Applications:

• Molecular and particle size distribution analysis.
• Powder fluidity analysis
• Particle compression density analysis
• Stability analysis in suspensions and emulsions
• Analysis of the dissolution rate of materials
• Determination of the reaction rate in solid systems