# Critical Point Phase Diagram

Tuesday, April 27, 2021

*Edit***Critical Point Phase Diagram**. For each substance, the conditions defining the critical point are the critical temperature, the critical pressure, and the critical density. So just to understand what's going on here, is that on this axis, I have pressure.

The procedure of critical point drying is an efficient method for drying delicate samples for SEM applications. Now lets put some numbers on the diagram to show the exact positions of the critical point. Critical behavior occurs at but one point of the phase diagram of a typical system.

### The critical point is the end point of a phase equilibrium curve, defined by a critical pressure Tp and critical temperature Pc.

Finding this critical point in the lab will require luck and an understanding of the possible experimental signatures.

The solid and liquid regions are separated by the melting curve of the substance, and the liquid and gas regions. This is a particularly interesting part of the phase diagram. The procedure of critical point drying is an efficient method for drying delicate samples for SEM applications.