Oxidant control of polydopamine surface chemistry in acids: a mechanism-based entry to superhydrophilic-superoleophobic coatings

Auteurs

F. Ponzio, J. Barthes, J. Bour, M. Michel, P. Bertani, J. Hemmerlé, M. d'Ischia, and V. Ball

Référence

Chemistry of Materials, vol. 28, no. 13, pp. 4697–4705, 2016

Description

Efficient surface functionalization with polydopamine films (PDA) can be easily achieved on virtually any object via single immersion in slightly basic dopamine solutions. In such conditions, however, poor homogeneity, low thickness and long time of reaction are usually the major limitations. Herein, we report a rational entry to the control of PDA deposition via chemical oxidation under slightly acidic conditions (pH 5.0) ensuring inhibition of uncontrolled autox-idation processes, to gain insight about the reaction mechanism and the impact of oxidation conditions on PDA struc-ture. Comparative chemical analysis of dopamine oxidation with three different oxidants (ammonium peroxodisulfate, sodium periodate and copper sulfate) revealed significant differences in the reaction course and allowed selection of periodate for the fast and homogeneous deposition of PDA films with thickness never reported before. Notably, PDA coatings with unprecedented superhydrophilic/superoleophobic properties were obtained under conditions of high periodate concentration, due to degradation of quinone units to yield carboxyl functions. Moreover these films still present biocompatibility and metal cation reduction properties. Overall, these results provide a novel rational method-ology to tailor PDA coatings for technological applications based on periodate control over dopamine polymerization and post-synthetic functional group modification.

Lien

doi: 10.1021/acs.chemmater.6b01587

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