Related Experiment Video
Updated: May 16, 2026

Mechanical Expansion of Steel Tubing as a Solution to Leaky Wellbores
Published on: November 20, 2014
Effect of gas pressure on negative thermal expansion in MOF-5
Nina Lock1, Mogens Christensen, Cameron J Kepert
1Dept of Chemistry and iNANO, Aarhus University, Denmark.
Abstract:
Powder diffraction is used to study thermal expansion properties of MOF-5 at moderate helium gas pressures: 1.7 bar (100-500 K) and 5-150 bar (150-300 K). The framework shows negative thermal expansion (NTE) at all pressures, but vibrational motions causing NTE are damped with increasing pressures, leading to decreased NTE.
Related Concept Videos
The Joule and Joule–Thomson Experiments
Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation
Pressure and Volume in an Adiabatic Process
Heat and Free Expansion
Thermal expansion and Thermal stress: Problem Solving
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in temperature (ΔT) is 55 °C.
Van der Waals Equation
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...

