Any ingredient or product termed freeze/thaw-stable shows a resistance to deterioration after repeated temperature cycling . Such temperature fluctuations cause the available water to form ice crystals, then melt, then refreeze, and so on. ... This means that usually a certain amount of water remains in a liquid state.
What does freeze/thaw mean?
Freeze-thaw occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart . Exfoliation occurs as cracks develop parallel to the land surface a consequence of the reduction in pressure during uplift and erosion.
How do you improve freeze/thaw stability?
- Use materials that has the ability to bind water. ...
- Use efficient stabilizers that can keep the formulation ingredients in a dispersed and homogeneous position throughout the formulation and reduce structural changes that can occur after thawing.
How do you test freeze/thaw stability?
Freeze-thaw testing is conducted by exposing the product to freezing temperatures (approximately -10 °C) for 24 hours , and then allowing it to thaw at room temperature for 24 hours.
What is considered a freeze/thaw cycle?
What is a freeze-thaw cycle? A freeze-thaw cycle is when the temperature fluctuates from above freezing (32F), to below freezing, and then back to above freezing . This is considered one freeze-thaw cycle, and Minneapolis, Minnesota experiences several freeze-thaw cycles each year.
How do you prevent freeze thaw?
- Using Deicing Chemicals. One of the simplest ways to prevent concrete freeze-thaw damage is with deicing chemicals. ...
- Reviewing Concrete Structure and Environment. High-quality concrete can also help to prevent deterioration. ...
- Applying a Sealer.
Where is freeze/thaw most common?
Where is freeze/thaw weathering most common? Freeze-thaw weathering is common in regions where the temperature often drops below freezing at night . It does not happen much in warm climates, or in very cold places like Antarctica, where the temperature seldom rises above zero!
Can you freeze an emulsion?
Both emulsion and emulsion remover can and will freeze . Most emulsions are not freeze/thaw stable. Depending on the emulsion’s chemistry, you can see a number of different results when opening the container.
Do cosmetics freeze?
Will makeup freeze? Yes, any makeup with water as an ingredient—that’s most liquid products, even if they’re viscous— will partially freeze .
How do you test accelerated stability?
We carry out our accelerated stability study by subjecting the product to an elevated level of stress like controlled changes in temperature or humidity. The testing period is determined by the time frame expected or required for the expiration of the product (i.e. 1 year, 2 years, etc).
What is stability testing protocol?
The stability test protocol should define the test parameters that would be used for evaluation of the stability samples . The tests that monitor the quality, purity, potency, and identity which could be expected to change upon storage are chosen as stability tests.
What is long term stability testing?
real-time (long-term) stability studies Experiments on the physical, chemical, biological, biopharmaceutical and microbiological characteristics of a drug , during and beyond the expected shelf-life and storage periods of samples under the storage conditions expected in the intended market.
How long does freeze/thaw take?
2.2.
The freeze–thaw process represents a “mild” homogenization procedure and it is usually used in combination with other homogenization methods. It consists of quickly freezing at −85°C and thawing at 4°C in sequence (the tubes could be thawed quickly at 6–10°C in a water bath for 10 min and kept at 4°C).
How does freeze/thaw damage occur?
The freeze-thaw cycle is a major cause of damage to construction materials such as concrete and brick assemblies. Freeze-thaw damage occurs when water fills the voids of a rigid, porous material and then freezes and expands.
What is the difference between freezing and thawing?
As nouns the difference between freezing and thawing
is that freezing is (uncountable|physics|chemistry) the change in state of a substance from liquid to solid by cooling to a critically low temperature while thawing is the process by which something thaws.
What is freezing and thawing effect?
The freeze-thaw phenomenon occurs when concrete is saturated with water and the temperature drops, freezing the H 2 O molecules . Since frozen water expands 9% of its original volume, it causes distress to the concrete structure. ... When water freezes, it occupies 9% more volume and creates microcracks.
