Incorporation of organic functions into mesoporous thin films through click chemistry

ANDREA V. BORDONI; ANE ESCOBAR; M. MERCEDES ZALDUENDO; RUSBEL CONEO RODRÍGUEZ; SERGIO E. MOYA; PAULA C. ANGELOMÉ

San Sebastián

Workshop; International Workshop on Self-assembly and Hierarchical Materials in Biomedicine: Drug Delivery, Tissue Engineering, Sensing and Safety Issues; 2018

BackgroundOxide-based mesoporous hybrid thin films possess the large specific surface area and the tunable pore size of the mesoporous materials, the mechanical and thermal stability of the inorganic oxide and the chemical flexibility of the organic functions. Therefore, these materials have potential for a wide variety of applications, including: catalysis, chemical detection, adsorption, immobilization of pollutants and controlled release of drugs or genes. Interestingly, he development of thin films containing the very useful acid and phosphonic groups is scarce, since there are no commercial silanes containing these moieties. In this work the synthesis and characterization of mesoporous thin films modified with COOH and PO(OR)2 groups is presented.MethodsThe groups were incorporated within the films taking advantage of the click thiol-ene reaction. Two routes were tested: (1) preparation of the functional silane and subsequent co-condensation with a commercial silane and (2) direct click reaction onto the thin films surface. All films were synthesized by Evaporation Induced Self Assembly pathway.Results, Discussion and ConclusionsBy the presented methodologies, it was possible to obtain mesoporous oxides with different amounts (from 5-20%) of five different carboxylic acids and two phosphonic acid derivatives in their walls. All materials were porous, with a degree of porous order dependent on the amount and nature of the incorporated silane. The functional groups were accessible for a variety of chemical reactions including: protonation, fluorescent labeling and adsorption of metal ions. Taking advantage of this last feature, Cu and Ag nanoparticles were grown inside the hybrid films, and the use of the composite for catalysis and sensing was demonstrated. What this project adds? The present work demonstrates the feasibility of the incorporation of non-commercial organic functions to mesoporous thin films through the utilization of click chemistry reactions. The photochemical radical thiol-ene addition was used to introduce COOH and PO(OR)2 groups, whose usefulness for several chemical processes was demonstrated.