The NGTi-based TIO2 film becomes very dense, smooth and hydrophilic after the etching process of the Ar plasma cleaner:
Nanocrystalline titanium (NGT1) has the advantages of non-toxicity, high specific strength, low elastic modulus and excellent biological activity. It has become a research hotspot in the field of biomaterials. TIO2 film is an excellent bioactive material. In recent years, it has gradually replaced hydroxyapatite coating. The latter has limited its application due to its poor bonding with metal implant materials.

Compared with the coarse-grained titanium-based TIO2 film, the TIO2 film has more excellent biological activity and film/substrate interface bonding force, and it is easy to obtain a single rutile TIO2 film on the surface of NGTi at room temperature. It is of great significance to improve the biological activity of NGTI funded redstone TIO2 film and expand the application prospects of NGTI/TIO2 composite materials in artificial joints and bone trauma products.
The high surface energy TIO2 film can promote the growth of osteoblasts. The methods to improve the surface energy of TIO2 film include ion doping ultraviolet light irradiation, plasma surface modification of Ar plasma cleaner and so on. After plasma treatment with Ar plasma cleaner, the NGTi-based TIO2 film becomes very dense, smooth and flat, and nano-scale pits appear. At room temperature, a large number of crystalline rutile TiO2 particles can be obtained on the surface of NGTi, but it is difficult to observe this phenomenon in TiO2 films prepared by magnetron sputtering technology on the surface of ordinary substrates (such as glass silicon wafers with coarse-grained metal bases).
Ar plasma cleaner plasma cleaner plasma has bombardment and cleaning effects on the film, which makes the discontinuous and non-dense particles on the surface of the TIO2 film removed by Ar plasma cleaning, leaving a flat, dense and smooth film surface . Ar plasma has a bombardment and etching effect, which can completely remove organic pollutants on the surface of the sample, thereby increasing the surface energy of the T1O2 film; after Ar plasma treatment, the T14+ on the surface of the TIO2 film is reduced and converted to T3+, which will generate electron voids. The hole pair, the hole reacts with the bridging oxygen of the rutile crystal plane to form an oxygen vacancy.
After 　　 Ar plasma cleaner plasma treatment, the TIO2 film will introduce oxygen vacancies, and water molecules will neutralize these oxygen vacancies to form OH groups, which improves the hydrophilicity of the TIO2 film. Ar plasma treatment significantly improves the hydrophilicity of NGT-based TiO2 films.