Hydrophobically modified methyl cellulose

Figure 2 The distance dependence characterizing exclusion of small solutes from macromolecular surfaces follows the same exponential behavior as the hydration force between macromolecules. The extent of exclusion can be extracted from the dependence of forces on solute concentration. ITexcess is the effective osmotic pressure applied by the solute in the bulk solution on the macromolecular phase, and np is the maximal pressure from complete exclusion, riexcess/rio = 1 then corresponds to complete exclusion and n excess/Ho = 0 means no inclusion or exclusion. The distance dependent exclusion the polar polyols adonitol (A) and glycerol ( ) from hydrophobically modified hydroxypropyl cellulose (FIPC) and of the nonpolar alcohols i-propanol ( ) and methyl pentanediol (MPD) ( ) from spermidine +-DNA is shown. As in Fig. 1, interaxial spacings are converted to surface separations. The apparent exponential decay length varies between 3.5 and 4 A (solid lines indicate fits to the data).

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