Immersional and Wetting Calorimetry Experiments

Measurements of the enthalpy changes accompanying the immersion and wetting phenomena may be performed with a Tian-Calvet type differential calorimeter [49, 54]. The experimental procedure includes several intermediate stages which may take much time, especially when the wetting enthalpy is measured as a function of the surface coverage by the vapour of the immersional liquid. 

The standard operating procedure for heat measurement is as follows [49,54]. The glass bulb containing the solid sample after the sample evacuation (and pre-coverage) stage is introduced into the calorimetric cell, which has been previously filled with 

When a given volume of the immersional liquid enters the bulb, the liquid level in the cell is lowered and there is some evaporation of the liquid to equilibrate the vapour pressure in the dead volume. This phenomenon yields an endothermic effect which is proportional to the dead volume Vb of the bulb  

Finally, the enthalpy change upon immersion of a solid in a given liquid per unit surface area of the solid is calculated as follows  

3 Hydrophilic-Hydrophobic Series and Harkins-Jura Method 

---

Fig. 6.7 Schematic representation of the sample preparation stage in immersional and wetting calorimetry experiments (a) solid sample enclosed in the glass bulb, (b) sample evacuation and pre-coverage, (c) seating the end of the tube, (d) assembling...

---