The mixing quality in nanoparticulate systems plays a fundamental role in the functional enhancement of advanced materials.In this study,we evaluate the effectiveness of mixing TiO_(2)(rutile)and ZrO_(2)(monoclinic)na...The mixing quality in nanoparticulate systems plays a fundamental role in the functional enhancement of advanced materials.In this study,we evaluate the effectiveness of mixing TiO_(2)(rutile)and ZrO_(2)(monoclinic)nanopowders using Raman mapping and energy-dispersive X-ray(EDX)spectroscopy within a scanning electron microscope(SEM).Eighteen experiments were carried out in an opposed jet fluidized bed,varying process time,mass ratio,and Laval nozzle back pressure.Raman mapping enabled spatially resolved identification of phases,while SEM/EDX provided high-resolution elemental composition.Both techniques indicated good overall inter-aggregate mixing efficiency,especially at a mass ratio of 1:1,with average Ti atomic fractions close to 0.607.Quantitative comparison showed that Raman micro spectroscopy yielded lower relative deviations from the expected values and required simpler sample preparation,making it a practical choice for assessing mixing homogeneity.Deviations from the expected compositions were more pronounced at other mass ratios(especially 1:2),likely owing to differences in particle size,density,and aggregation tendencies.Finally,in contrast to previous intra-aggregate mixing studies,the current results suggest that inter-aggregate composition tends to stabilize near equimolar proportions regardless of the initial mass ratio,highlighting self-regulating behavior at the macro scale.展开更多
基金Funding of this work by Deutsche Forschungsgemeinschaft(DFG)in the framework of Priority Programme 2289“Hetero-aggregates”is gratefully acknowledged(Project ID 462314498-Bück,Schmidt).
文摘The mixing quality in nanoparticulate systems plays a fundamental role in the functional enhancement of advanced materials.In this study,we evaluate the effectiveness of mixing TiO_(2)(rutile)and ZrO_(2)(monoclinic)nanopowders using Raman mapping and energy-dispersive X-ray(EDX)spectroscopy within a scanning electron microscope(SEM).Eighteen experiments were carried out in an opposed jet fluidized bed,varying process time,mass ratio,and Laval nozzle back pressure.Raman mapping enabled spatially resolved identification of phases,while SEM/EDX provided high-resolution elemental composition.Both techniques indicated good overall inter-aggregate mixing efficiency,especially at a mass ratio of 1:1,with average Ti atomic fractions close to 0.607.Quantitative comparison showed that Raman micro spectroscopy yielded lower relative deviations from the expected values and required simpler sample preparation,making it a practical choice for assessing mixing homogeneity.Deviations from the expected compositions were more pronounced at other mass ratios(especially 1:2),likely owing to differences in particle size,density,and aggregation tendencies.Finally,in contrast to previous intra-aggregate mixing studies,the current results suggest that inter-aggregate composition tends to stabilize near equimolar proportions regardless of the initial mass ratio,highlighting self-regulating behavior at the macro scale.
