Download citation
Download citation
link to html
A kinetic study of the solid-state polymerization of disulfur dinitride (S2N2) to polysulfur nitride [(SN)x] has been performed, combining monochromatic high-energy (λ = 0.3263 Å) synchrotron radiation X-ray powder diffraction, a large-area (ø = 220 mm) CCD-based X-ray image-intensifier detector and Rietveld refinement. Recently developed techniques for detector calibration and reduction of two-dimensional images to one-dimensional diffraction patterns have been employed for data processing/analysis. Good fits were obtained after Rietveld refinement [Rp = 8.4%, wRp = 9.4%, sin(θmax)/λ = 0.585 Å−1] of diffraction patterns of S2N2 from images with 2 s exposure time. The solid-state polymerization of S2N2 to (SN)x, was followed at a maximum rate of two diffraction images per minute. Scale factors and cell parameters for S2N2 and β-(SN), as functions of time were readily obtained after Rietveld refinement of the diffraction patterns obtained from each individual image throughout the polymerization. The polymerization was preceded by a lattice distortion of S2N2, and at 50% conversion the a axis had decreased by about 1% and the c axis had increased about 1%. The polymerization yielded not only the expected polymer β-(SN)x, but also a small amount of a compound that could be another phase of (SN)x.
Follow J. Synchrotron Rad.
Sign up for e-alerts
Follow J. Synchrotron Rad. on Twitter
Follow us on facebook
Sign up for RSS feeds