Gemini Surfactant as a Template Agent for the Synthesis of More Eco-Friendly Silica Nanocapsules

abstract

Silica mesoporous nanocapsules are a class of smart engineered nanomaterials (ENMs) applied in several fields. Recent studies have highlighted that they can exert deleterious effects into marine organisms, attributed to the use of the toxic cationic surfactant N-hexadecyl-N,N,N-trimethylammonium bromide (CTAB) during the synthesis of ENMs. The present study reports the successful synthesis and characterization of novel gemini surfactant-based silica nanocapsules. The gemini surfactant 1,4-bis-[N-(1-dodecyl)-N,N-dimethylammoniummethyl]benzene dibromide (QSB2-12) was chosen as a more environmentally-friendly replacement of CTAB. Nanocapsules were characterized by scanning electron microscopy (SEM), Fourier-transformed infrared spectroscopy (FTIR), dynamic light scattering (DLS), thermogravimetric analysis (TGA) and N-2 adsorption-desorption isotherms. Short-term exposure effects of new ENMs were evaluated in four marine species (Nannochloropsis gaditana, Tetraselmis chuii and Phaeodactylum tricornutum) and the microcrustacean (Artemia salina). The replacement of the commercial cationic surfactant by the gemini surfactant does not change the structure nor the environmental behaviour in seawater of the newly synthesised silica nanocontainers. Additionally, it is demonstrated that using gemini surfactants can reduce the toxicity of novel silica nanocapsules towards the tested marine species. As a result, environmentally-friendly ENMs can be obtained based on a safe-by-design approach, thereby fitting the concept of Green Chemistry.

keywords

IN-VITRO; COATINGS; TOXICITY; DRUG; ECOTOXICITY; RELEASE; SPACER

subject category

Chemistry; Engineering; Materials Science; Physics

authors

Kaczerewska, O; Sousa, I; Martins, R; Figueiredo, J; Loureiro, S; Tedim, J

Groups

G3 - Electrochemical Materials, Interfaces and Coatings

Projects

Smart anticorrosion coatings based on nanocontainers loaded with novel, eco-friendly cationic gemini surfactants as efficient corrosion inhibitors for carbon steel in seawater. (EcoGEmCoat)

SMARTAQUA-Development of SMART nanostructured layers for sensing corrosion in AQUAtic structures (SMARTAQUA)

acknowledgements

O. Kaczerewska received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 792945 (EcoGemCoat). R. Martins was hired under the Scientific Employment Stimulus-Individual Call (CEECIND/01329/2017), funded by national funds (OE), through FCT, in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of 29 August, changed by Law 57/2017, of 19 July. This work was developed under the framework of the NANOGREEN project (CIRCNA/BRB/0291/2019), funded by the Portuguese Foundation for Science and Technology (FCT) through national funds (OE). This work was also carried out in the framework of SMARTAQUA project, which is funded by the Foundation for Science and Technology in Portugal (FCT), the Research Council of Norway (RCN-284002), Malta Council for Science and Technology (MCST), and co-funded by European Union's Horizon 2020 research and innovation program under the framework of ERA-NET Cofund MarTERA (Maritime and Marine Technologies for a new Era). This work was developed within the scope of the project CICECO-Aveiro Institute of Materials (UIDB/50011/2020; UIDP/50011/2020) and CESAM-Centre for Environmental and Marine Studies (UIDB/50017/2020 + UIDP/50017/2020) financed by national funds.