Room‐temperature bonding method of bioactive ultrathin glass film on titanium by a dissolution‐polymerization reaction

Abstract

Freestanding ultrathin glass film (UGF) of 45S5 bioglass was successfully bonded on a Ti substrate by the room-temperature bonding method. 45S5 UGFs with a thickness of 1~4 μm were fabricated by the glass-blowing technique, and the UGF was attached on the Ti plate at room temperature with a water layer between them. The bonding strength was about 370 mJ/m 2 just after bonding, and it increased during storing in the ambient atmosphere at room temperature and reached about 900 mJ/ m 2 after 9 hours storage. The interfaces of the UGF and Ti substrate during the bonding process were analyzed by an X-ray photoelectron spectroscopy. The as-prepared UGF was found to have surface layers with a high content of Na 2 O and low content of SiO 2 , and the dissolution of Na 2 O-rich component into water layer induced depolymerization and polymerization of SiO 2 network to form Si-O-Si bonds between the UGF and Ti plate and then to increase the bonding strength during storage. This work presents the simple technique to laminate the bioactive glass layer on the surface of the metal without post heat treatment.

Low‐temperature bonding of glasses: The role of plasma‐engrafted surface amino groups

“…This hypothesis is based on the role of basic catalysis in solvents for sol–gel synthesis 39,46,47 . A similar bonding mechanism based on this phenomenon has been proposed at the previous study of glass‐Ti bonding interface with Na 2 O‐rich layer and liquid water 48 . However, this reaction pathway is unlikely for our system where the amount of adsorbed water on the SiO 2 glass surface should be very small compared to liquid water 44 .…”

“…39,46,47 A similar bonding mechanism based on this phenomenon has been proposed at the previous study of glass-Ti bonding interface with Na 2 O-rich layer and liquid water. 48 However, this reaction pathway is unlikely for our system where the amount of adsorbed water on the SiO 2 glass surface should be very small compared to liquid water. 44 Further, a reaction scheme via intra-surface proton transfer is also possible.…”

Hydrophilic property of titanium oxide aiming for bio‐applications

“…Among these applications, to improve its compatibility with the human body, especially bone bonding, many studies on modification and functionalization of the titanium surface have been reported continuously. [1][2][3][4][5][6][7] Regarding the abovementioned functionalization of titanium metal, several types of chemical treatment and electrical treatment related to TiO 2 formation are widely performed. However, most of these treatments are relatively complicated processes, for example, (a) hydrothermal reaction using strong acids and higher pressures 6 and (b) anodic oxidation using a higher voltage and strong acids.…”