Poly(amidoamine) (PAMAM) dendrimers with different generations (G ¼ 2, 3 and 4) were synthesized, peripherally modified with aniline pentamers and studied for their redox and dopable behavior under different pH conditions. It was found that the electron transition of the p B -p Q band red-shifted and the size of PAMAM G2 decreased in an alkaline medium. The chemical oxidation process and the color change of these modified dendritic macromolecules were measured by cyclic voltammetry (CV) and electrochromism. All of the dendrimers showed three redox peaks in the CV. The current density of the voltammograms increased with increasing the number of aniline pentamer segments at the periphery. A drastic color change was observed when a linear potential sweep was applied. The thermal properties of the electroactive dendrimers were evaluated by differential scanning calorimetry and thermogravimetric analysis.

A series of amphiphilic poly(amidoamine) dendrimers (PAMAM, G2-G5) composed of a hydrophilic core and a hydrophobic shell of aniline pentamer (AP) were synthesized and characterized. The modified dendrimers self-assembled to vesicular aggregates in water with the critical aggregation concentration (CAC) decreased in the order of G2 > G3 > G4 > G5. It was found that the modified dendrimers self-organized into spherical aggregates with a bilayer vesicular structures and that the dendrimers in higher generation have more order structure, which may be attributed to the crystallization induced by the compacted effect of AP segments. In addition, larger spherical vesicles were observed under acidic and alkaline conditions, as compared with sizes of aggregates in neutral medium. At low pH, the tertiary amine groups of PAMAM-AP were transformed to ammonium salts; the polarons were formed from AP units by doping with strong acids, thereby leading to the stability of vesicular aggregates being better than that in double distilled water. Nevertheless, in high pH environment, the deprotonation of PAMAM-AP caused the enhancement of π-π interactions, resulting in generation of twins or multilayered vesicles.

The superhydrophobic surface (SHS) applied for corrosion protection in this study was prepared from an organic fluorinated polyacrylate incorporated with methyltriethoxysilane (MTES)-based silsesquioxanes spheres. The SHS, with a contact angle of about 153.2 , was coated onto the surface of cold-rolled steel (CRS) with spin-coating technology. The coating materials applied as anticorrosive coatings were based on a series of electrochemical corrosionprotection measurements in saline conditions. The SHS coat-ing on CRS was found to provide superior corrosion protection to that of the hydrophobic organic coating in a series of electrochemical measurements in 3.5 wt % aqueous NaCl electrolyte. This form of coating could also provide better corrosion protection to coated CRS substrates and could serve as an effective barrier against aggressive species. V C 2012Wiley Periodicals, Inc. J Appl Polym Sci 126: E48-E55, 2012

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