Fluorocarbon bonded phase

N. D. Danielson, L. G. Beaver, J. Wangsa, Eluoropoly-mers and Fluorocarbon Bonded Phases as Column Packings for Liquid Chromatography , J. Chromat. 1991, 544,187. 

ABS plastic, a polymer consisting of polybutadiene spheroids is dispersed in a continuous phase of poly(styrene—acrylonitrile). The chromic acid attacks the polybutadiene at a much higher rate than the continuous phase. This gives an excellent microroughened surface with superior metal-to-plastic bond strength. A typical recommended formulation consists of 20 vol % sulfuric acid, 420 g/L chromic acid, and 0.1—1.0% of a fluorocarbon wetting agent. The plastic is treated with this formulation for 6—10 min at 60—65°C. 

Reta, M., Carr, R W., Sadek, P. C., and Rutan, S. C., Comparative study of hydrocarbon, fluorocarbon and aromatic bonded RP-HPLC stationary phases by linear solvation energy relationships. Anal. Chem., 71, 3484-3496, 1999. 

The smaller band, labelled A, is at a frequency sufficiently close to that of the gas-phase HDO (3707 cm 1 for OH stretch and 2727 cm 1 for OD stretch) that it must be considered due to OH groups not involved in 0-H 0 hydrogen bonding. It was shown in ref. that the frequencies are in fact very nearly those that would be expected for water molecules on the periphery of the aqueous medium, with one or both OH or OD groups exposed to the fluorocarbon, but also engaging in some water-water and water-ion interactions. 

Perfluorination techniques have been developed for the conversion of many hydrocarbons to their perfluorinated counterparts. Fluorocarbons are chemically inert because of their kinetically unreactive carbon skeletons and have been considered as blood substitutes because of their high oxygen solubility. The thermal stability and low secondary bond forces of fluorocarbons have contributed to their use as greases, lubricants, and vapor-phase heat transfer reagents. 

---