@InProceedings{MarcondesUedaOliv:2009:TrRiFl,
               author = "Marcondes, A. R. and Ueda, M{\'a}rio and Oliveira, R. M.",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)}",
                title = "Treatment of Rigid and Flexible Polymers by Plasma Immersion Ion 
                         Implantation for Space Applications",
                 year = "2009",
         organization = "International Workshop on Plasma-Based Ion Implantation and 
                         Deposition, 10. (PPI\&D).",
             abstract = "Surface modification of polymers has growth a lot in the last 
                         decades due to the necessity to combine the unique bulk properties 
                         of those materials with some selected surface properties that can 
                         be tailored for specific applications. Among the rigid polymers 
                         suitable for space use there is the Ultra-High Molecular Weight 
                         Polyethylene (UHMWPE), a polymer with outstanding physical and 
                         chemical properties which is currently used in multiple areas. 
                         Despite the unique properties of UHMWPE, some effort need to be 
                         made in order to adequate its surface properties to withstand the 
                         Low Earth Orbit (LEO) space environment which is rich in harmful 
                         species like atomic oxygen, UV-rays and space debris. Flexible 
                         polymers have also a widespread use in satellites and space 
                         station but as any other material it shows use life limitation due 
                         to atomic oxygen degradation. In this work is presented the 
                         results that have been achieved when treating UHMWPE and films of 
                         KaponŽ by Plasma Immersion Ion Implantation (PIII) where the 
                         workpieces were pulsed to a high negative voltage in nitrogen and 
                         argon plasma respectively. For UHMWPE pulse intensities of 5, 10 
                         and 15kV were applied to the samples. Others parameters like pulse 
                         duration (10 and 20{\`{\i}}s), treatment time (15, 30, 45 and 
                         60min), and metallic grid distance to the sample (2 and 10 mm) 
                         were also varied. In all cases Raman spectroscopy has indicated 
                         the formation of Diamond-Like Carbon (DLC) in the UHMWPE surface 
                         with improvement on properties like hardness (by a factor of 1.6) 
                         and elastic modulus, as confirmed by nanohardness measurements. 
                         XPS characterization was used to assure the nitrogen ions 
                         implanted in the polymer were linked to carbon atoms instead of 
                         forming clusters. XPS also indicated a relative high fraction of 
                         sp3 carbons which is in agreement with the same information 
                         obtained from Raman spectra.The fraction has varied from 10 to 60% 
                         depending on the treatment condition. The several set of treatment 
                         conditions have led to some important conclusions about the 
                         influence of pulse intensity, time treatment, pulse duration and 
                         grid distance on the DLC formation. In general DLC formation, or 
                         the intensities of G and D bands related to, respectively, sp2 and 
                         sp3 carbons increases with higher pulse intensities. The treatment 
                         time has the same influence on DLC formation. Grid distance seems 
                         to have little influence on DLC formation but based on data 
                         obtained so far it is possible to conclude that closer the grid 
                         better the ion implantation. And with respect to pulse duration, 
                         the results have confirmed what was expected. Longer pulse 
                         duration seems worse to DLC formation. That was confirmed by Raman 
                         spectroscopy since longer the pulse duration higher the expected 
                         accumulated charge in the polymer surface. Samples of KaptonŽ 
                         films have also been treated by PIII using an aluminum source of 
                         ions. The previous results have shown a significant color 
                         modification in the film surface. The ion implantation and the 
                         expected increase in the surface hardness will be confirmed by XPS 
                         and nanohardness characterization in the following.",
  conference-location = "S{\~a}o Jos{\'e} dos Campos, SP",
      conference-year = "7-11 Sept.",
        urlaccessdate = "20 maio 2024"
}