Evaluation of fine particle removal capability of multi inner stage cyclone

Adsorbate Formation/Removal and Plasma‐Induced Evolution of Defects in Graphitic Materials

“…Another possible explanation is that the islands were created by reactive oxygen from the plasma itself, reacting with the graphene surface to form sp 3 ‐type defects. Following the previous discussion on defect evolution upon oxygen‐plasma treatment, based on Raman spectroscopy experiments (Section 2.1), sp 3 ‐type defect generation substantiates the interpretation of Zandiatashbar et al and Lee et al [ 26,28 ] Both groups concluded that prior to reaching a maximum in the intensity ratio between the D‐peak and G‐peak as a function of plasma‐treatment time (transition between stage 1 and stage 2), sp 3 ‐type defects occurred predominantly for graphene samples.…”

“…This method allows a detailed analysis of the in‐plane and out‐of‐plane interactions of a sharp tip with adsorbates and graphitic surfaces. [ 41 ] Based on the findings of Zandiatashbar et al [ 28 ] and Lee et al, [ 26 ] we propose that for 30 s of plasma treatment predominantly sp 3 ‐type defects, such as epoxy, carbonyl, and ether groups, should be visible. Depending on the thickness of the few‐layer graphene/graphite sample, longer plasma‐treatment durations should either lead to the formation of further sp 3 ‐type defects or to vacancies whose presence we also aimed to confirm by the multifrequency AFM method.…”

“…[ 43 ] This argument is supported by the trend of the intensity ratio I 2D /I G (Figure 2b,d, blue), which was initially larger for thinner areas of the flake, but decreased with plasma‐treatment time. Lee et al [ 26 ] found that during stage 1 (prior to reaching the maximum value of I D /I G ) oxygen tended to adsorb on the graphene surface to form sp 3 ‐type defects, such as epoxy, carbonyl, and ether groups. The epoxy groups exhibited, according to the authors, the lowest defect formation energy and were energetically favored to form on the graphene surface.…”

“…[ 27 ] Zandiatashbar et al [ 28 ] reported that the introduction of defects in graphene samples during plasma treatment could be strongly reduced by placing the sample upside down in the chamber on two glass slides, resulting in a shielded configuration. An illustration of the shielded configuration was shown by Lee et al [ 26 ] Additionally, they found that the ratio between the D‐ and G‐peak as a function of plasma‐treatment time of monolayer graphene had a local maximum at the transition between predominantly sp 3 ‐type and predominantly vacancy‐type defects. [ 28 ] Because the number of defects and the number of layers both influence the Raman spectra of few‐layer graphene/graphite samples, we examined the effect of plasma treatment on the few‐layer graphene/graphite samples during stepwise ablation of the graphene layers.…”

“…Smaller intensity ratios between the D‐ and the D’‐peak (≈3.5) were attributed to boundaries in the graphite. Lee et al [ 26 ] defined different stages of defect generation based on the aforementioned intensity ratio between D‐ and D’‐peak. They deduced that the transition between sp 3 ‐ (stage 1, crystalline defects) and vacancy‐type defects (stage 2, nanocrystalline defects) occurred at I D /I D’ ≈ 7.…”