Filmix particles subpopulation are surfactant-stabilized gas microbubbles

2 Combined evidence that the larger-diameter Filmix particles (i.e.. subpopulation) are surfactant-stabilized gas microbubbles 

Several arguments in favor of the belief that the population of larger-diameter particles, detected in these photon correlation spectroscopy measurements on artificial microbubble surfactant solutions, are indeed microbubbles (cf. Chapter 12) are as follows  

1) The surfactant mixture used (CAV-CON Filmix 3) is identical to that used to form the artificial gas-in-water emulsions described in Chapter 9, where the concentrated emulsion particles observed were all above 0.3 pm in diameter (which is the lower detection limit of the laser-based flow cytometer instrument) and therefore did not include the co-existing micelles. 

2) The surfactant solution was passed through a precleaned, membrane filter which removed all solid debris greater than 6.0 pm in diameter. 

3) Since none of the surfactants used are liquids, oil-in-water microemulsions or emulsions cannot be the basis for the existence of the larger-diameter population (or even the smaller-diameter population) of particles detected. 

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