Polarity of organic liquids and adsorbents

The general rule is that a polar adsorbate will tend to prefer that phase which is the more polar, i.e. it will be strongly adsorbed by a polar adsorbent from a non-polar solution. Similarly, a non-polar 

Langmuir [29] gave an instructive interpretation to this rule. The work to transfer one mole of solute from solution to surface is [30, p. 95]  

Traube found that for each additional CH2 group the concentration required to give a certain surface tension was reduced by a factor of 3, i.e. if C i = 3C then y = and  

This may be regarded as the work required to bring one group from the body of the solution to the surface. Adamson assumed this to imply that the chains were lying flat on the surface but suggested that this was undoubtedly an over simpliflcation. 

Harkins and Dahlstrom [31] have shown that the oxides of titanium, tin and zinc act like water in attracting polar rather than nonpolar groups. Thus in oils any -COOH, -OH, -CN and other similar groups orient towards the oxide powder and the hydrocarbon groups orient themselves towards the oil. 

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