@Article{OishiBoteRezeFerr:2017:StSuFu,
               author = "Oishi, Silvia Sizuka and Botelho, Edson Cocchieri and Rezende, 
                         Mirabel Cerqueira and Ferreira, Neidenei Gomes",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Universidade Estadual Paulista (UNESP)} and {Universidade Federal 
                         de S{\~a}o Paulo (UNIFESP)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)}",
                title = "Structural and surface functionality changes in reticulated 
                         vitreous carbon produced from poly(furfuryl alcohol) with sodium 
                         hydroxide additions",
              journal = "Applied Surface Science",
                 year = "2017",
               volume = "394",
                pages = "87--97",
                month = "Feb.",
             keywords = "Poly(furfuryl alcohol), Reticulated vitreous carbon, Surface 
                         functionalities, Microstructure, NaOH oxidation.",
             abstract = "The use of sodium hydroxide to neutralize the acid catalyst 
                         increases the storage life of poly(furfuryl alcohol) (PFA) resin 
                         avoiding its continuous polymerization. In this work, a 
                         concentrated sodium hydroxide solution (NaOH) was added directly 
                         to the PFA resin in order to minimize the production of wastes 
                         generated when PFA is washed with diluted basic solution. Thus, 
                         different amounts of this concentrated basic solution were added 
                         to the resin up to reaching pH values of around 3, 5, 7, and 9. 
                         From these four types of modified PFA two sample sets of 
                         reticulated vitreous carbon (RVC) were processed and heat treated 
                         at two different temperatures (1000 and 1700 °C). A correlation 
                         among cross-link density of PFA and RVC morphology, structural 
                         ordering and surface functionalities was systematically studied 
                         using Fourier transform infrared spectroscopy, scanning electron 
                         microscopy, Raman spectroscopy, X-ray diffraction, and X-ray 
                         photoelectron spectroscopy techniques. The PFA neutralization (pH 
                         7) led to its higher polymerization degree, promoting a 
                         crystallinity decrease on RVC treated at 1000 °C as well as its 
                         highest percentages of carboxylic groups on surface. A NaOH excess 
                         (pH 9) substantially increased the RVC oxygen content, but its 
                         crystallinity remained similar to those for samples from pH 3 and 
                         5 treated at 1000 °C, probably due to the reduced presence of 
                         carboxylic group and the lower polymerization degree of its cured 
                         resin. Samples with pH 3 and 5 heat treated at 1000 and 1700 °C 
                         can be considered the most ordered which indicated that small 
                         quantities of NaOH may be advantageous to minimize continuous 
                         polymerization of PFA resin increasing its storage life and 
                         improving RVC microstructure.",
                  doi = "10.1016/j.apsusc.2016.10.112",
                  url = "http://dx.doi.org/10.1016/j.apsusc.2016.10.112",
                 issn = "0169-4332",
             language = "en",
           targetfile = "Oishi_structural.pdf",
        urlaccessdate = "02 maio 2024"
}