Effect of temperature on the properties of substances
Substance Stability：
Certain substances may be inactivated or undergo property changes at high temperatures, e.g., enzymes in biological samples are easily inactivated at high temperatures, thus affecting the separation.
Solubility:
Changes in temperature affect the solubility of a substance. In some cases, lowering the temperature can increase the solubility of a solute in a solvent, while in other cases the opposite may be true. This depends on the nature of the solute and solvent and their interaction.
Viscosity：
The viscosity of a fluid varies with temperature. In general, an increase in temperature reduces the viscosity of the fluid, which facilitates the flow and mixing of the fluid, but may also affect the diffusion and distribution of substances during the separation process.
Effect of temperature on separation methods
Chromatography：
In chromatographic separations, temperature is one of the most important factors affecting the separation. The setting of column temperature affects the equilibrium of analyte partitioning between the stationary phase and mobile phase, which in turn affects the separation and peak shape. Generally speaking, increasing the column temperature can improve the separation, but it may also lead to poor peak shape or decomposition of certain compounds. Therefore, it is necessary to choose the appropriate column temperature according to the specific situation.
Centrifugation：
The effect of temperature on centrifugal separations is mainly in the form of changes in the properties of the sample. For example, high temperatures may lead to volatilization or degradation of certain components in the sample, thus affecting the separation. In addition, temperature may also affect the operational stability and service life of the centrifuge.
Hydrate Method：
In gas separation, the operating temperature has a significant effect on the hydrate method. Lowering the operating temperature may increase the separation rate of gases such as CO, because the lower temperature provides a greater driving force (subcooling), allowing more gas molecules to enter the hydrate phase. However, this may also lead to an increase in the rate of loss of the remaining gas components.
Practical application considerations
Equipment Requirements：
Different equipment and separation methods have different operating temperature requirements. Designers and operators need to pay close attention to the temperature rating and data sheet specifications of the equipment to ensure that it operates within the specified temperature range.
Safety：
There are certain safety risks associated with operating at high or low temperatures. For example, high temperatures may cause equipment to overheat, catch fire or explode; low temperatures may cause equipment to freeze, damage or affect personnel health. Therefore, appropriate safety measures need to be taken during operation.
Economic Benefits：
The choice of operating temperature also needs to be considered in terms of economic efficiency. Too high a temperature will increase energy consumption and equipment maintenance costs: too low a temperature may require additional cooling equipment and energy consumption. Therefore, the need to ensure that the separation effect under the premise of selecting economically rational operating temperature.
The operating temperature has an important influence on the separation effect. In practical application, it is necessary to select the appropriate operating temperature according to the specific situation, and take corresponding measures to ensure the safe operation of the equipment and the optimization of the separation effect.