The aim of this study was to determine the solubility of CO2 in perfluorodecalin (PFD) which is frequently used as efficient liquid carrier of respiratory gases in bioprocess engineering. The application of perfluorinated liquid in a microsystem has been presented. Gas-liquid mass transfer during Taylor (slug) flow in a microchannel of circular cross section 0.4 mm in diameter has been investigated. A physicochemical system of the absorption of CO2 from the CO2/N2 mixture in perfluorodecalin has been applied. The Henry’s law constants have been found according to two theoretical approaches: physical (H = 1.22·10-3 mol/m3Pa) or chemical (H = 1.26·10-3 mol/m3Pa) absorption. We are hypothesising that the gas-liquid microchannel system is applicable to determine the solubility of respiratory gases in perfluorinated liquids.
A mathematical model of a hybrid culture system supported with a stationary layer of liquid perfluorochemical (PFC) as a source of O2 for cells which grow in the aqueous phase of culture medium has been developed and discussed. The two-substrate Monod kinetics without inhibition effects, i.e. the Tsao-Hanson equation, has been assumed to characterise the biomass growth. The Damköhler number which relates the growth rate to the mass transfer effects has been used to appraise the regime (i.e. diffusion-limited or kinetics) of the whole process. The proposed model predicted accurately previously published data on the submerged batch cultures of Nicotiana tabacum BY-2 heterotrophic cells performed in a culture system supported with a stationary layer of hydrophobic perfluorodecalin as a liquid O2 carrier. Estimated values of the parameters of the model showed that the process proceeded in the kinetics regime and the growth kinetics, not the effects of the mass transfer between aqueous phase and liquid PFC, had essential influence on the growth of biomass.
Fully synthetic, biochemically inert and water-immiscible liquid perfluorochemicals (PFCs) are recognised as flexible liquid carriers/scavengers of gaseous compounds (respiratory gases mainly, i.e. O2 and CO2) and increasingly applied in bioprocess engineering. A range of unmatched physicochemical properties of liquid PFCs, i.e. outstanding chemo- and thermostability, extremely low surface tension, simultaneous hydro- and lipophobicity, which result from carbon chain substitution with fluorine atoms (the most electronegative chemical element) and the presence of intramolecular C-F bonds (the strongest single bond known in organic chemistry) have been described in detail. Exceptional propensity to solubility of respiratory gases in liquid perfluorinated compounds has been widely discussed. Advantages and disadvantages of bioprocess applications of liquid PFCs in the form of a pure PFC as well as in an emulsified form have been pointed out. A liquid PFC-mediated mass transfer intensification in various types of microbial, plant cell and animal cell culture systems: from miniaturised microlitre-scale cultures, via biomaterial-based scaffolds containing culture systems, to litre-scale bioreactors, has been reviewed and elaborated on bearing in mind the benefits of bioprocesses.