Department of Biomedical Sciences, Texas A&M Health Science Center, College of Dentistry , Dallas, Texas 75246, United States.
Department of Electrical and Computer Engineering, New York Institute of Technology , Old Westbury, New York, 11568, United States.
J Phys Chem B. 2017 Sep 28;121(38):8991-9005. doi: 10.1021/acs.jpcb.7b05885. Epub 2017 Sep 14.
Silicon oxynitride (Si-O-N) is a new biomaterial in which its O/N ratio is tunable for variable Si release and its subsequent endocytotic incorporation into native hydroxyapatite for enhanced bone healing. However, the effect of nitrogen and hydrogen bonding on the formation and structure of hydroxyapatite is unclear. This study aims to uncover the roles of H and N in tuning Si-O-N surface bioactivity for hydroxyapatite formation. Conformal Si-O-N films were fabricated by plasma-enhanced chemical vapor deposition (PECVD) onto Ti/Si substrates. Fourier transform infrared spectroscopy (FTIR) and Rutherford backscattering spectrometry (RBS) analysis indicated increased Si-H and N-H bonding with increased N content. Surface energy decreased with increased N content. X-ray absorbance near edge structure (XANES) analysis showed tetrahedral coordination in O-rich films and trigonal coordination in N-rich films. O-rich films exhibited a 1:1 ratio of 2p to 2p electron absorbance, while this ratio was 1.73:1 for N-rich films. Both Si and N had a reduced partial charge for both O- and N-rich films, whereas O maintained its partial charge for either film. O-rich films were found to exhibit random bonding SiON, while N-rich films exhibited random mixing: [Si-Si]-[Si-O]-[Si-N]. Thus, hydrogen bonding limits random nitrogen bonding in Si-O-N films via surface Si-H and N-H bonding. Moreover, increased nitrogen content reduces the partial charge of constituent elements and changes the bonding structure from random bonding to random mixing.
氮化硅氧（Si-O-N）是一种新型生物材料，其 O/N 比可调，可实现 Si 的释放，并随后被内吞进入天然羟基磷灰石，从而增强骨愈合。然而，氮和氢键对羟基磷灰石的形成和结构的影响尚不清楚。本研究旨在揭示 H 和 N 在调节 Si-O-N 表面生物活性以促进羟基磷灰石形成中的作用。采用等离子体增强化学气相沉积（PECVD）在 Ti/Si 基底上制备了共形 Si-O-N 薄膜。傅里叶变换红外光谱（FTIR）和卢瑟福背散射光谱（RBS）分析表明，随着 N 含量的增加，Si-H 和 N-H 键合增加。表面能随 N 含量的增加而降低。X 射线吸收近边结构（XANES）分析表明，富 O 薄膜中存在四面体配位，富 N 薄膜中存在三角配位。富 O 薄膜的 2p 到 2p 电子吸收比为 1:1，而富 N 薄膜的 2p 到 2p 电子吸收比为 1.73:1。对于 O-和 N-富的薄膜，Si 和 N 的部分电荷均降低，而 O 保持其部分电荷。富 O 薄膜表现出随机键合的 SiON，而富 N 薄膜表现出随机混合：[Si-Si]-[Si-O]-[Si-N]。因此，通过表面 Si-H 和 N-H 键合，氢键限制了 Si-O-N 薄膜中随机氮键合。此外，增加的氮含量降低了组成元素的部分电荷，并改变了从随机键合到随机混合的键合结构。
