We synthesized and characterized novel amphiphilic polyesters with both hydrophilic and hydrophobic functionalities. The polyesters are soluble in organic and aqueous media and reveal the formation of inverse architectures whose behavior could be correlated to their chemical structure. We foresee that the amphiphilic properties of the polyesters reported here are obviously the basis of new architectures both in solution and on the solid surfaces, which could be used in a broad range of applications. The described synthesis of the copolymers is very simple and is based on commercially available products. That makes this approach attractive in various uses.

This article presents a new approach to building up self-adjustable invertible polymer coatings at solid surfaces. The approach is based on a two-step process. In the first step, the surface of dispersed TiO2 or silicon wafers was functionalized with the aid of a reactive copolymer, viz., poly(styrene-alt-maleic anhydride) (PSM), to which, in the second step, the chains of amphiphilic oligoester have been tethered. The latter contains both hydrophilic poly(ethylene glycol) and hydrophobic aliphatic dibasic acid moieties being alternately distributed along the oligomer chains. It is shown that the titania modified in this way can form stable suspensions in both polar (water) and nonpolar (toluene) media. Moreover, 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 by polarity from that of the previous medium. An environmentally induced switching of the surface properties has been observed via the measurement of the wetting contact angles and scanning force microscopy (SFM) of silicon wafers covered by PSM with tethered oligoester chains. These experiments give strong support for the predicted capability of such polymer coatings to switch their environmental appearance (i.e., to behave as a self-adjustable invertible interface because of the ability of the tethered amphiphilic oligoester chains to change their conformations in response to environmental changes in such a manner so as to adapt and enhance their compatibility with the surrounding media).

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