Cooling Rate
Cooling Rate - Related Videos
09:32
Cooling Rate Dependent Ellipsometry Measurements to Determine the Dynamics of Thin Glassy Films
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Cited by 2 •
2016
Here, we present a protocol for cooling rate dependent ellipsometry experiments, which can determine the glass transition temperature (Tg), average dynamics, fragility and the expansion coefficient of the super-cooled liquid and glass for a variety of glassy materials.
02:44
Heating and Cooling Curves
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2020
When a substance—isolated from its environment—is subjected to heat changes, corresponding changes in temperature and phase of the substance is observed; this is graphically represented by heating and cooling curves. For instance, the addition of heat raises the temperature of a solid; the amount of heat absorbed depends on the heat capacity of the solid (q = mcsolidΔT). According to thermochemistry, the relation between the amount of heat absorbed or released by a substance, q, and its...
11:21
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
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Cited by 1 •
2017
We present a parametric driving method to cool an ultracold Fermi gas in a crossed-beam optical dipole trap. This method selectively removes high-energy atoms from the trap by periodically modulating the trap depth with frequencies that are resonant with the anharmonic components of the trapping potential.
02:53
Reaction Rate
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2020
The rate of reaction is the change in the amount of a reactant or product per unit time. Reaction rates are therefore determined by measuring the time dependence of some property that can be related to reactant or product amounts. Rates of reactions that consume or produce gaseous substances, for example, are conveniently determined by measuring changes in volume or pressure. The mathematical representation of the change in the concentration of reactants and products, over time, is the rate...
08:32
Measurement of Outgassing Rates of Steels
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Cited by 5 •
2016
A protocol for the measurement of outgassing rates of hydrogen from ordinary steel vacuum chambers using the rate-of-pressure rise method is presented.
FAQs
Cooling rate affects crystallization by changing the time available for nucleation and crystal growth. When heat leaves gradually, molecules can reorganize into larger, more ordered structures. A faster temperature decrease changes this balance, potentially limiting ordered growth and producing smaller crystals or an amorphous solid. This makes the thermal profile an important variable when designing a crystalline material.
Rapid cooling can restrict the molecular rearrangement needed to form an ordered crystal structure. As solidification or crystallization proceeds quickly, impurities may remain enclosed rather than being excluded from the growing structure. The resulting material can therefore contain more trapped impurities, along with smaller crystals or amorphous regions, making the selected cooling conditions important for controlling composition and structure.
Cooling rate influences whether a chemical system has time to approach an equilibrium arrangement or instead preserves a kinetically favored outcome. Slower cooling provides more opportunity for molecular reorganization, while rapid cooling can limit that adjustment as the material changes phase. Consequently, the cooling profile can affect which structures or products are ultimately observed.
In recrystallization, controlling the cooling rate helps determine the balance among crystal order, crystal size, and impurity retention. Gradual cooling can support the formation of larger, more ordered crystals, whereas rapid cooling may yield smaller crystals or retain impurities within the solid. Researchers select the cooling conditions according to the desired purity and physical characteristics of the recovered material.
Cooling rate provides a controlled variable for examining how chemical materials respond as they lose thermal energy. Changing the rate can reveal differences in phase changes, structural formation, and the tendency toward ordered or amorphous solids. This information helps connect observed thermal behavior with molecular motion and supports interpretation of material properties during cooling.
During solidification, cooling rate helps determine the structure that develops as a material changes from a less ordered state to a solid. Adjusting it can influence crystal size, structural order, impurity retention, and other physical properties. These effects make controlled cooling relevant when preparing materials whose purity, particle size, or final characteristics must meet a specific objective.