Tham khảo tài liệu 'tribology lubricants and lubrication 2012 part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 242 Tribology - Lubricants and Lubrication Mass m z Fig. 25. Mass spectra of negative fragment ions for sample A as determined by TOF-SIMS upper spectrum initial lower spectrum after 60 min X-ray exposure by XPS Initial After 60min X-ray explosured Lub. film thickness nm Lub. film coverage Lub. film thickness nm Lub. film coverage Sample F 98 over 88-91 Sample G 98 over 94-95 Sample H 98 over 94-95 Table 3. Film thickness and coverage ratio of lubricant before and after XPS damage Abrasion test The water contact angle for sample F sample G and sample H before and after the abrasion test is listed in table 4. The XPS spectrum for each sample before and after abrasion test is shown in figures 26 - 28. Figures 29 - 31 show the topographic image and the phase image for each sample before and after abrasion test image on the upper left image initial topographic image upper right image initial phase image lower left image topographic image after abrasion test lower right image phase image after abrasion test . The results in table 4 indicate that the water contact angles in the case of sample G and sample H decreased slightly after the abrasion test was performed. In contrast the water contact angle of sample F decreased drastically from 116 to 89 after the sample was scratched by a 2 kg weight over 600 strokes. In the case of sample F it seems that the water Characterization of Lubricant on Ophthalmic Lenses 243 Fig. 26. Changing chemical structure of Cis spectrum for sample F before and after the abrasion test Binding Energy KV Fig. 27. Changing chemical structure of C1s spectrum for sample G before and after the abrasion test Binding Energy KV Fig. 28. Changing chemical structure of C1s spectrum for sample H before and after the abrasion .
