Analysis of thermal expansion of liquids

Analyzing the thermal expansion of liquids allows us to measure how a fluid's volume changes with temperature. This fundamental physicochemical property is crucial for predicting the behavior of liquids subjected to temperature variations , particularly in the packaging , environmental , materials , and technical fluid (oils, solvents, lubricants, chemicals, and cosmetics) .

Understanding how a liquid expands or contracts depending on the temperature is essential for designing safe and efficient systems , avoiding overpressures, controlling mixtures, and ensuring product stability over time.

Principle and objectives of thermal expansion measurement

When a liquid is heated, its volume tends to increase due to increased molecular agitation. This phenomenon is quantified by the coefficient of volumetric thermal expansion (β) , expressed in K⁻¹, which indicates the relative change in volume for a given degree of temperature increase.

The objective of this analysis is to:

• Determine the coefficient of thermal expansion of a pure liquid or a mixture;
• Evaluate volumetric stability under different temperatures;
• Anticipating the internal pressure in a container subjected to heating;
• Optimize the formulations of liquid products sensitive to temperature variations;
• Ensuring material-container compatibility in industrial packaging.

This data is essential for the safety, design and performance of products, particularly in the chemical, cosmetic, food and energy sectors.

Analytical methods used

The analysis is generally performed by dilatometry, the reference technique for measuring changes in volume or length as a function of temperature.
Two types of equipment can be used:

• The capillary dilatometer: direct measurement of the volume occupied by the liquid in a sealed capillary tube immersed in a thermostatic bath;
• Automated volumetric measurement systems: modern instruments capable of continuously monitoring volume variation under precise thermal control (± 0.01 °C).

The data obtained allows us to draw a volume-temperature curve, from which the coefficient of expansion β is calculated according to the relation:
β = (1/V₀) × (ΔV/ΔT).

Industrial applications

The thermal expansion of liquids is a critical parameter in many fields:

• Packaging and conditioning: anticipation of internal pressures in bottles, tubes or tanks subjected to temperature variations (transport, storage);
• Cosmetics and fine chemicals: stability control of lotions, gels and organic solvents;
• Agri-food: study of the thermal behavior of oils, juices, drinks or fermented products;
• Environment and energy: analysis of heat transfer fluids, biodegradable oils, technical solvents;
• Formulation of industrial mixtures: prediction of compatibility and stability as a function of temperature.

This analysis also helps to improve process safety and reduce the risks of leakage, container deformation or uncontrolled evaporation.

Technical specifications and associated standards

Thermal expansion tests are performed according to standardized protocols (e.g., ASTM D2879 , ISO 11357 for organic liquids).
Measured parameters include:

• The coefficient of volumetric expansion (β);
• The total volume change between two given temperatures;
• The dimensional stability temperature of the liquid.

The tests are carried out under strictly controlled conditions (temperature, atmosphere, pressure) by partner laboratories accredited to ISO 17025 , guaranteeing the reliability and traceability of the results.

YesWeLab Expertise and Support

YesWeLab provides you with a network of laboratories specializing in thermal and rheological testing, capable of accurately measuring the thermal expansion of any type of industrial liquid.
Our scientific team supports you in:

• Choosing the measurement method best suited to your products (capillary, volumetric, instrumental dilatometry);
• Interpreting the results according to your industrial constraints (packaging, formulation, safety, regulations);
• The implementation of combined tests (stability, compatibility, viscosity, density).

Thanks to the YesWeLab digital platform, you can manage your analysis requests, track your samples and view your technical reports online.

Further analyses recommended

For a complete understanding of the thermal and rheological behavior of liquids, YesWeLab recommends:

• Measurement of viscosity and rheological behavior
• Material-container compatibility
• Measurement of density and specific gravity

These additional services allow for a complete characterization of the physical and thermal properties of liquids, guaranteeing their stability and safety under all conditions of use.