@Article{EscanioAntuTravCora:2023:InSoCa,
               author = "Escanio, Camila Alves and Antunes, Erica Freire and Trava-Airoldi, 
                         Vladimir Jesus and Corat, Evaldo Jos{\'e}",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)}",
                title = "Influence of sodium and calcium contaminant in the growth of 
                         carbon nanotube on rayon-based carbon fibers",
              journal = "Materials Science and Engineering B: Advanced Functional 
                         Solid-State Materials",
                 year = "2023",
               volume = "287",
                pages = "e116089",
                month = "Jan.",
             keywords = "Alkali metals, Catalyst, Rayon, Carbon fiber, Carbon nanotubes.",
             abstract = "This study investigated the role of contaminants commonly found on 
                         rayon-based carbon fibers (CF) for the carbon nanotubes (CNT) 
                         synthesis. The most common contaminant found on CF is sodium. From 
                         the experi-mental results, sodium contaminant indeed performed as 
                         a catalyst, but with low efficiency. However, some CF samples also 
                         contained calcium as a contaminant, and Ca presence made higher 
                         density and better-quality CNT growth. Probably Ca acts as the 
                         reducing agent, keeping Na in metallic form along the entire 
                         growth process. XPS data suggests a new view of sodium 
                         oxide/hydroxide to sodium carbonate transition after CNT 
                         synthesis. On CF samples with calcium, sodium keeps activity and 
                         carbonate does not form, differently of the sample containing just 
                         Na. CF free of contaminants (PAN-based CF) helps set apart the 
                         effects and Raman Spectroscopy picked up sodium and calcium 
                         effects on the CNT crystalline quality. The sodium presence in 
                         rayon-based CF worsens CNT quality when growing from the foreign 
                         iron-cobalt catalyst. By another hand, calcium presence helps 
                         keeping iron-cobalt nanoparticles surface reduced. Images of Field 
                         Emission Gun Scanning Electron Microscopy (FEG-SEM), Energy 
                         Dispersive Spectroscopy (EDS), and X-ray Diffraction (XRD) also 
                         supported the analysis.",
                  doi = "10.1016/j.mseb.2022.116089",
                  url = "http://dx.doi.org/10.1016/j.mseb.2022.116089",
                 issn = "0921-5107",
             language = "en",
           targetfile = "1-s2.0-S0921510722004779-main.pdf",
        urlaccessdate = "11 maio 2024"
}