Adsorption of Particulate Solids on Textiles1

Adsorption uf particulate solids and synthetic soil on cellulose and synthetic fabrics has been studied by a dynamic method involving high speed rotation of the solid and the substrate in a closed chamber. The results confirm that adhesion, and not mechanical entrapment, is the dominant soiling mechanism. Adsorption of particulate matter on the fiber surface increases with increasing pressure and mechanical work done during the soiling process. Some desorption of already adsorbed solid particles occurs because of abrasion; fibers with a higher toughness index retain adsorbed particles more firmly. The amount of particulate matter adsorbed on the fabric increases with the increasing amount of soil contacted with the fabric. A linear log-log plot of the two amounts resembles formally the Freundlich adsorption iso therm. The amount of soil adsorbed increases linearly with the logarithm of soiling time; the kinetics are apparently of second order. A linear relationship exists also between the amount of soil adsorbed and the reciprocal of rotational velocity of the impeller driving the solid and the substrate. It is shown that fabrics with different construction respond differently to the mechanical action of the soiling process. The geometry of the fabric can be a more important factor determining soil resistance than the chemical composition of the fiber. A surface film of either hydrophilic or hydrophobic liquids on hydrophilic or hydrophobic fibers increases soil adsorption.