期刊
ACS APPLIED MATERIALS & INTERFACES
卷 7, 期 49, 页码 27362-27372出版社
AMER CHEMICAL SOC
DOI: 10.1021/acsami.5b08957
关键词
phosphate glass; bioresorbable; bioactive thin films; osseointegration; dissolution; sputtering; PVD
资金
- MeDe Innovation
- EPSRC Centre for Innovative Manufacturing in Medical Devices [EP/K029592/1]
- EPSRC [EP/K029592/1] Funding Source: UKRI
- Engineering and Physical Sciences Research Council [EP/K029592/1] Funding Source: researchfish
Quinternary phosphate-based glasses of up to 2.67 mu m, deposited by radio-frequency magnetron sputtering, were degraded in distilled water and phosphate-buffered saline (PBS) to investigate their degradation characteristics. Magnetron-sputtered coatings have been structurally compared to their compositionally equivalent melt-quenched bulk glass counterparts. The coatings were found to have structurally variable surfaces to melt-quenched glass such that the respective bridging oxygen to nonbridging oxygen bonds were 34.2% to 65.8% versus 20.5% to 79.5%, forming metaphosphate (PO3)(-) (Q(2)) versus less soluble (P2O7)(4-) (Q) and (PO4)(3-) (Q(0)), respectively. This factor led to highly soluble coatings, exhibiting a t(1/2) degradation dependence in the first 2 h in distilled water, followed by a more characteristic linear profile because the subsequent layers were less soluble. Degradation was observed to preferentially occur, forming voids characteristic of pitting corrosion, which was confirmed by the use of a focused ion beam. Coating degradation in PBS precipitated a (PO3)(-) metaphosphate, an X-ray amorphous layer, which remained adherent to the substrate and seemingly formed a protective diffusion barrier, which inhibited further coating degradation. The implications are that while compositionally similar, sputter-deposited coatings and melt-quenched glasses are structurally dissimilar, most notably, with regard to the surface layer. This factor has been attributed to surface etching of the as-deposited coating layer during deposition and variation in the thermal history between the processes of magnetron sputtering and melt quenching.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据