Perfluoropolyether main

The first heavier than water internal tamponade was introduced in 1987 by Chang with LPFC [1]. The two perfluorocarbons most used are perfluorooctane and perfluorodecaline. Perfluorotributylamine, perfluoropolyether, perfluorooctyl-bromide and perfluorophenanthrene are less used. LPFC are transparent fluids and are not miscible in water and their main characteristic is their high density (1.76-2.03) [2], Their properties are summarised in Table 1. 

As previously mentioned, another class of fluoropolymers known to be readily soluble in CO2 are perfluoropolyethers (PFPEs) [1]. A unique class of fluoropolymers, PFPE polymers and copolymers have been established as high performance materials, exhibiting low surface energies and low moduli, as well as excellent thermal and chemical stabilities. PFPEs are primarily found in high-performance lubricant applications, e.g., for magnetic data storage media and as heat exchanger fluids. One of the main industrial processes for the production of PFPEs is photooxidation of fluoroolefins [41]. Currently, only TFE and HFP are used commercially in this process. Typically, HFP is photooxidized in bulk because of its very low reactivity, while TFE requires an inert diluent in order to prevent homopolymerization of the olefin. 

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