Busca avançada
Ano de início
Entree


Biomimetic PDMS-hydroxyurethane terminated with catecholic moieties for chemical grafting on transition metal oxide-based surfaces

Texto completo
Autor(es):
de Aguiara, Kelen R. ; Rischka, Klaus ; Gaetjen, Linda ; Noeske, Paul-Ludwig Michael ; Cavalcanti, Welchy Leite ; Rodrigues-Filho, Ubirajara P.
Número total de Autores: 6
Tipo de documento: Artigo Científico
Fonte: Applied Surface Science; v. 427, p. 10-pg., 2018-01-01.
Resumo

The aim of this work was to synthesize a non-isocyanate poly(dimethylsiloxane) hydroxyurethane with biomimetic terminal catechol moieties, as a candidate for inorganic and metallic surface modification. Such surface modifier is capable to strongly attach onto metallic and inorganic substrates forming layers and, in addition, providing water-repellent surfaces. The non-isocyanate route is based on carbon dioxide cycloaddition into bis-epoxide, resulting in a precursor bis(cyclic carbonate)-polydimethylsiloxane(CCPDMS), thus fully replacing isocyanate in the manufacture process. A biomimetic approach was chosen with the molecular composition being inspired by terminal peptides present in adhesive proteins of mussels, like Mefp (Mytilus edulis foot protein), which bear catechol moieties and are strong adhesives even under natural and saline water. The catechol terminal groups were grafted by aminolysis reaction into a polydimethylsiloxane backbone. The product, PDMSUr-Dopamine, presented high affinity towards inhomogeneous alloy surfaces terminated by native oxide layers as demonstrated by quartz crystal microbalance (QCM-D), as well as stability against desorption by rinsing with ethanol. As revealed by QCM-D, X-ray photoelectron spectroscopy (XPS) and computational studies, the thickness and composition of the resulting nanolayers indicated an attachment of PDMSUr-Dopamine molecules to the substrate through both terminal catechol groups, with the adsorbate exposing the hydrophobic PDMS backbone. This hypothesis was investigated by classical molecular dynamic simulation (MD) of pure PDMSUr-Dopamine molecules on SiO2 surfaces. The computationally obtained PDMSUr-Dopamine assembly is in agreement with the conclusions from the experiments regarding the conformation of PDMSUr-Dopamine towards the surface. The tendency of the terminal catechol groups to approach the surface is in agreement with proposed model for the attachment PDMSUr-Dopamine. Remarkably, the versatile PDMSUr-Dopamine modifier facilitates such functionalization for various substrates such as titanium alloy, steel and ceramic surfaces. (C) 2017 Elsevier B.V. All rights reserved. (AU)

Processo FAPESP: 13/05279-3 - Adesivos biomiméticos baseados em uretanas derivadas de poli(dimetilsiloxano) utilizando fixação de CO2
Beneficiário:Kelen Menezes Flores Rossi de Aguiar
Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
Processo FAPESP: 11/08120-0 - Filmes nanoestruturados: impacto da arquitetura dos filmes contendo nanopartículas e fosfotungstato sobre as propriedades fotoativas
Beneficiário:Ubirajara Pereira Rodrigues Filho
Modalidade de apoio: Auxílio à Pesquisa - Regular
Processo FAPESP: 11/06019-0 - Fixação de CO2 e síntese de co-polímeros de poliuretana e polisilicona incorporado em ormosils: utilização como filmes bioativos e sistemas condutores iônicos
Beneficiário:Kelen Menezes Flores Rossi de Aguiar
Modalidade de apoio: Bolsas no Brasil - Doutorado