| 摘要 |
The invention relates to a composition based on natural zeolite and to a process for coating therewith biomedical implants, based on Ti alloy, to be used in orthopedics and dentistry, the composites on the so-coated implants being imparted a tetragonal crystalline structure and an elasticity modulus more similar to the human bone, acting as a barrier between the Ti alloy and the corrosive medium. According to the invention, the composition consists of the following elements expressed in weight percentage: 10...30% tribomechanically activated natural zeolite clinoptilolite, which is gradually introduced, while stirring, in a basic solution obtained by mixing 5...10% sodium hydroxide in hot distilled water. The claimed process consists in obtaining the clinoptilolite basic suspension, by stirring for 30 minutes, at a temperature of 80° C, and introducing the same in an autoclave made of stainless steel and lined with teflon, the implant being vertically suspended in the basic suspension with two teflon rings placed perpendicularly to one another, it being previously cleaned with a solution comprising less than 10% caustic soda and less than 5% non-ionic wetting agents and glycol, abundantly rinsed with distilled water, dried by pressing between two filter paper sheets and kept at the room temperature for 1..2 h before being immersed into the basic clinoptilolite suspension, after which the autoclave is introduced into a convection oven and kept therein for 24...72 h at a temperature ranging between 100...230° C, then the autoclave being taken out of the oven and cooled suddenly with tap water, after which the implant is taken out, washed with distilled water, pressed between filter paper sheets and left to dry at the room temperature. |
