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Ground-granulated blast-furnace slags (GGBS) are by-products of the pig iron production and have been used as a cement additive for almost 150 years. 1,2 GGBS is a common constituent in CEM II and CEM III (EN 197-1), replacing clinker/Portland cement up to 95% in some applications. GGBS-containing binders have superior long-term properties, including increased chemical and mechanical resistance and decrease the CO 2 footprint of the material. 2-7 Starting from a certain addition level, early compressive strength development is below the ordinary Portland cement or cements with lower additions levels. 2,3,6 However, large differences exist in short-term reactivity of GGBS. It was shown that in different modern day GGBS, 2 day compressive strength in mortars with 75 % GGBS varied by a factor ×4. 8 Main source of variation of the reactivity of GGBS in various cementitious systems was their chemical composition and intensive research has been carried out on the influence of major element composition. 8-15 Differences in reactivity are likely due to differences in chemical durability of the slag glass, as for strength development GGBS needs to dissolve and reprecipitate as cementitious phase. 6 Chemically, GGBS are glasses (>99%) of the CaO-Al 2 O 3-SiO 2 compositional system, also containing significant amounts of Mg and Ti, and a wide variety of other minor and trace elements. 2,6,16 Structurally, main network formers are Si and the majority of Al, as often observed in calcium-aluminosilicate glasses. 16-18 Ca and Mg are present in network modifier positions. 16

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Surface composition, fluorine distribution, and morphology were determined for polyimide films modified downstream from microwave plasmas containing CF4/O2. Complementary analytical techniques including x-ray photoelectron spectroscopy, Rutherford backscattering spectroscopy, and scanning electron microscopy yielded a more complete understanding of polyimide fluorination and subsequent etching of the modified film. Depth of fluorination increased nonlinearly with treatment time for films exposed downstream from a CF4-rich plasma. Exposure downstream from an O2-rich plasma resulted in a reduction of thickness in both the fluorinated layer and the unmodified polyimide during etching. Finally, a model for fluorination of polyimide and subsequent removal is proposed.

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Rutherford backscattering spectrometry (RBS), routinely used for the analysis of inorganic materials, is finding applications in the characterization of organic polymeric films, which may be sensitive to damage. To investigate ion beam effects on polyimide, pyromellitic dianhydride–oxydianiline films were exposed to He2+ ions in the energy range of 1.9 to 3.6 MeV, fluences of 0.25 to 3.0×1015 ions/cm2, and sample temperatures of 298 and 130 K. RBS, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, optical interferometry, and enhanced image analysis techniques were used to determine film changes during irradiation. RBS spectra collected in the range of specified fluences are essentially superimposable, except for differences in their signal-to-noise ratios. The damage is optically observed as a darkening of the film. At 130 K, there was no motion of the gold marker in the film, indicating no loss of mass. During irradiation, molecular rearrangements are detected and include cleavage of imide rings.

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