Aqueous dispersions of paraffins are used in the production of paper, woodworking, and in the production of particle boards (chipboard). The use of paraffin dispersions as heat carriers (thermofluids) in the form of systems that change their phase state (Phase Change Material, PCM) is considered promising. The use of such materials makes it possible to more efficiently accumulate thermal energy and release heat in a certain temperature range during phase transitions.
Common methods for studying phase behavior of paraffins are adiabatic and differential scanning calorimetry. To study the rotational phases of paraffins, X-ray diffraction methods are used. In this work, the authors propose an original method for determining the temperatures of phase transitions of paraffins (melting, crystallization, and rotator phases), based on optical methods. A feature of this method is that paraffin for research is presented in the form of a nanodispersion in water with a characteristic particle size of about 100 nm.
For a series of n-alkanes (from C19H40 to C42H86), aqueous dispersions were prepared and their physicochemical properties were studied. The temperatures of phase transitions of the studied n-alkanes were determined. For some samples, the dependence of the zeta potential of particles in the dispersion on the pH of the medium was measured. The investigated dispersions were subjected to thermal cycles, during which melting and crystallization of the dispersed phase occurred. More than 600 such cycles were carried out without disturbing the stability of the dispersion.
The work was funded by RFBR, project number 20-08-00984.
|Affiliation of speaker||Oil and Gas Research Institute of RAS|
|Publication||Impact Factor journals|
|Position of speaker||с.н.с.|