Transitiometry
Experimental vessels

 


     Standard high pressure vessels (max.. pressure 400 MPa and max. internal volume ~1 ml or max. press. 200 MPa and max. internal volume ~4 ml) are presented in Figs.1, 2 and 3.


Fig. 1. Standard high pressure vessels ( measuring and reference) connected to a manifold fixed on the transitiometric stand.



Fig. 2. Standard high pressure vessels fixed in a special holder for opening or closing procedures.


Fig. 3. A starch-water suspension extruded from the experimental vessel after isobaric thermal gelatinization at 100 MPa.


Other high pressure vessels have also been developed and are available:

1. Modified classical transitiometric vessels with a special closing head allowing to dose portions of low critical point liquids, such as ethane or CO2 in order to prepare quantitatively asymmetric mixtures directly in the experimental vessel, such as {solid or low volatile macromolecules + supercritical fluids} in order to prepare transitiometrically full (p,T,x) diagrams of asymmetric systems. The hydraulic liquid is mercury. The best transitiometric mode is quasi-isochoric temperature scan, with both thermal and mechanical outputs clearly visible. The whole internal active volume can be varied from 4 cm3 to ~0.5 cm3. Pressure limit is 200 MPa (higher pressure are possible).

2. Experimental vessels closed with a very flexible SS bellows connected to a very sensitive displacement digital recording unit with a linear resolution of 0.2 - 1 micron and precision of 0.1 percent. Such vessels are especially adapted to simultaneous measurement of Cp and thermal expansivity of liquids and to investigate phase transitions over large intervals of temperatures at fixed pressures. The vessels permit also to eliminate mercury as hydraulic fluid. Very good functioning can be obtained at pressures up to 50 MPa, although higher pressure are possible.

3. Experimental vessels with very flexible SS bellows placed outside of the calorimetric detector, but connected to the interior of that part of the experimental vessel which is placed inside the calorimetric detector. Such vessels are extremely well adapted to study intrusion/extrusion of fluids in porous media, but can be also easily adapted to study other phenomena, such as precise simultaneous measurements of volume expansion coefficient and isothermal compressibility coefficient, including the phase transitions in systems of biophysical importance.

4. A selection of experimental vessels with an electrically driven mechanical stirrer which can be used up to at least 50 MPa, other pressures can be negotiated.

We are open to elaborate any other vessels or to co-operate to adapt our vessels to investigation of other, even most difficult processes.