Liquid breathing can not effectively protect the lung from biophysical forces associated with the gas ventilator. New application modes for PFC have been developed. Partial liquid ventilation (PLV) involves filling the lungs with a fluid. This fluid is perfluorocarbon, also called Liquivent or Perflubron. The liquid has some unique properties. It has a very low surface tension, similar to surfactant, a substance that is produced in the lungs to prevent the alveoli from collapsing and sticking together during exhalation. It also has a high density, oxygen readily diffuses through it, and it may have some anti-inflammatory properties. In PLV, the lungs are
Surface tension known as equilibrium. The horizontal component of is canceled by the adhesive force, . The more telling balance of forces, though, is in the vertical direction. The vertical component of must exactly cancel the difference of the forces along the solid surface, . Since the forces are in direct proportion to their respective surface tensions, we also have: where This means that although the difference between the liquid–solid and solid–air surface tension, , is difficult to measure directly, it can be inferred from the liquid–air surface tension, , and the equilibrium contact angle, , which is a function of the