Thermal Expansion of Solvent Mixture question

[OptiPessimist]

Hello,

Currently, I am working on a science project involving the creation of silica aerogels through the process of freeze-drying. As a result, i need to experiment with mixtures of solvents with low thermal expansion coefficients (so the crystallization of the solvents will not damage the aerogel matrix) However, i have hit a huge impediment.

While it is relatively simple to look up the thermal expansion coefficients for a given solvent,

how would one determine the thermal expansion coefficient for a mixture of solvents? (For example, the thermal expansion coef of a mixture of Tert Butanol and Propanol?)

Would the coefficient be nearly the same if the solvents were in solid state? (For they will be frozen, then sublimated)

 

[Zefram]

Hello,

Thank you for reaching out with your question. Determining the thermal expansion coefficient for a mixture of solvents can be a bit more complicated than for a single solvent. The thermal expansion coefficient is a measure of how much a material expands or contracts when its temperature changes. In a mixture of solvents, each solvent will have its own thermal expansion coefficient, and the overall coefficient will depend on the proportions of each solvent in the mixture.

One way to determine the thermal expansion coefficient for a mixture of solvents is to use a technique called differential scanning calorimetry (DSC). This method measures the heat flow into or out of a sample as its temperature is changed, and can provide information on thermal expansion coefficients for mixtures.

Another method is to use a dilatometer, which measures the change in volume of a sample as its temperature changes. This can also provide information on thermal expansion coefficients for mixtures.

To answer your question about whether the coefficient would be the same in the solid state, it is important to note that thermal expansion coefficients can vary depending on the state of the material (solid, liquid, gas). Therefore, the coefficient for a mixture of solvents in the solid state may be different from the coefficient for the same mixture in the liquid state. This is because the molecules are arranged differently and have different interactions in each state.

I hope this information helps with your project. Best of luck with your experiments!

 

[quicknote]

Hello,

Thank you for sharing your project with me. The issue of determining the thermal expansion coefficient for a mixture of solvents is a common challenge in scientific research. There are a few factors to consider when trying to determine the thermal expansion coefficient for a solvent mixture.

Firstly, it is important to note that the thermal expansion coefficient of a mixture is not simply the average of the individual thermal expansion coefficients of the solvents in the mixture. This is because the individual solvents may interact with each other in a way that affects their thermal expansion behavior.

One approach to determining the thermal expansion coefficient of a solvent mixture is through experimental methods. This involves measuring the volume change of the mixture as it is heated or cooled and using this data to calculate the thermal expansion coefficient. However, this method can be time-consuming and may not be feasible for your project.

Another approach is to use theoretical models and equations to predict the thermal expansion coefficient of the mixture. These models take into account the properties of the individual solvents and their interactions in the mixture. However, it is important to note that these models may not accurately predict the thermal expansion coefficient for all solvent mixtures.

To answer your question about the thermal expansion coefficient being the same in the solid state, it is likely that the coefficient would be similar since freezing and sublimation do not significantly change the molecular interactions in the mixture. However, it is always best to verify this through experimental data or theoretical models.

I hope this information helps you in your project. Best of luck with your research!