Authors: A. Kohut, A. Voronov and W. Peukert
Affilation: Friedrich-Alexander-University of Erlangen-Nuremberg, Germany
Pages: 165 - 168
Keywords: invertible polymers, synthesis, colloidal stability
A new range of amphiphilic polyesters with both hydrophilic and hydrophobic functionalities alternately distributed in the polymer backbone has been synthesized. These polyesters are soluble in aqueous and organic media, where they reveal inverse behavior that could be correlated to their chemical structure. The work suggests a simple method for fabricating self-adjustable invertible polymer coatings made of the amphiphilic polyesters. For the modified titanium dioxide particles, we observed an essential increase in colloidal stability after the modification with the invertible oligomer tails. Multiple drying/redispersion cycles demonstrate the ability of the modified titania particles after their removal from one type of dispersion and consequent drying to be redispersed in dispersing media strongly differing in polarity from the previous medium. Environmentally induced switching of the surface properties has been observed via AFM investigations of silicon wafers covered with the tethered polyester chains. These experiments strongly support the capability of such polymer coatings to switch their environmental appearance as a result of the ability of the attached amphiphilic polyester chains to change their conformations in response to environmental changes.