Silicone-geranium essential oil blend for long-term antifouling coatings.

This study explores the potential of geranium essential oil as a natural solution for combating marine biofouling, addressing the environmental concerns associated with commercial antifouling coatings. Compounds with bactericidal activities were identified by 13Carbon nuclear magnetic resonance (13C NMR). Thermogravimetric analysis (TGA) revealed minimal impact on film thermal stability, maintaining suitability for antifouling applications. The addition of essential oil induced changes in the morphology of the film and Fourier transform infrared spectroscopy (FTIR) analysis indicated that oil remained within the film. Optical microscopy showed an increase in coating porosity after immersion in a marine environment. A total of 18 bacterial colonies were isolated, with Psychrobacter adeliensis and Shewanella algidipiscicola being the predominant biofilm-forming species. The geranium essential oil-based coating demonstrated the ability to reduce the formation of Psychrobacter adeliensis biofilms and effectively inhibit macrofouling adhesion for a duration of 11 months.

Influência do tratamento superficial na resistência de uniäo dos reparos de resina composta / Influence of superficial treatment on the shear bond strength of composite resin repairs

Este estudo avaliou, in vitro, a resistência de uniäo de seis técnicas diferentes de tratamento superficial em reparos de resina composta. Os maiores valores de resistência de uniäo foram obtidos com o tratamento superficial utilizando-se ácido fosfórico, aplicaçäo de um agente de sinalizaçäo e aplicaçäo do adesivo