Properties of decalin as a solvent in thermal field-flow fractionation

Cis-trans-decahydronaphthalene (67.85 % trans + 32.15 % cis, here briefly r eferred to as cis-trans-decalin) as a possible solvent for thermal field-fl ow fractionation is proposed. Different features such as solvent properties with respect to low polarity polymers, availability of basic physicochemic al data (viscosity and thermal conductivity in a convenient temperature ran ge), low toxicity and low cost are emphasized. Retention data over a wide r ange of cold wall temperatures and thermal gradients were collected. The nu correction factor and lambda retention data were determined for polystyren e samples over a relative molecular mass range of 11,300-3,950,000 g mol(-1 ) From these data, selectivity values were determined and compared to the com monly found values for polystyrene in different solvent systems. The averag e value of -0.6 found here for cis-trans-decalin falls in the optimum selec tivity solvent-domain. Cis-trans-decalin is thus fully proven as an optimum solvent for ThFFF.