A high pressure cell for supercritical CO2 on-line chemical reactions studied with x-ray techniques

作者：Hermida Merino Daniel; Portale Giuseppe; Fields Peter; Wilson Richard; Bassett Simon P; Jennings James; Dellar Martin; Gommes Cedric; Howdle Steven M^*; Vrolijk Benno C M; Bras Wim

来源：Review of Scientific Instruments, 2014, 85(9): 093905.

DOI：10.1063/1.4895717

A versatile high pressure X-ray sample cell has been developed for conducting in situ time-resolved X-ray scattering experiments in the pressure and temperature regime required (pressures up to 210 bars and temperatures up to 120 degrees C) for chemical reactions in supercritical fluids. The large exit opening angle of the cell allows simultaneous performance of SAXS-WAXS experiments. Diamond windows are used in order to benefit from the combination of maximum strength, minimal X-ray absorption and chemical inertia. The sample cell can also be utilised for X-ray spectroscopy experiments over a wide range of photon energies. Results of the online synthesis of a block copolymer, poly(methyl methacrylate-block-poly(benzyl methacrylate), by Reversible Addition-Fragmentation Chain Transfer (RAFT) in a supercritical CO2 dispersion polymerisation will be discussed. The contribution of the density fluctuations, as function of temperature, to the X-ray scattering signal has been quantified in order to allow appropriate background subtractions.

• 出版日期2014-9