The present invention relates to the technical field of composite materials, and in particular, to a functional composite particle and a preparation method thereof.
Biocompatible ceramics not only have the mechanical compatibility and stability of ceramics, but also have affinity and biological activity with biological tissue, and can be applied in biological, medical, chemical, and other fields related to human body or animal body. However, single biocompatible ceramics have some limitations in practical application. For example, when the biocompatible ceramics are applied in artificial joints, it is easy to cause bacterial infections and, more seriously, local complications of bones may occur.
Combining metallic particles having specific functions with biocompatible ceramics is a solution to the limitations of the biocompatible ceramics above. For example, in patent CN10293614A, a given amount of metallic silver powder is mixed in a ceramic raw material, and the mixture is sintered under a normoxic or oxygen-enhanced environment to form ceramics that can release silver ions, such that a certain antibacterial effect is achieved. However, in the sintering process of the ceramics, excessive temperature would make it difficult to locate the metallic silver at a fixed position, resulting in that the metallic silver and the ceramic material are not evenly distributed in the finished product; moreover, silver in high temperature is also easy to be oxidized by oxygen in the environment, and thus the antibacterial effect of silver ions would be lost. In addition, the bonding force between the metallic silver and the ceramic material is weak, and during specific use, the release time of silver ions is relatively short, so it is difficult to achieve a lasting antibacterial effect.
Therefore, the existing biocompatible ceramics can be further improved.
In order to improve the property of the existing biocompatible ceramics and enhance the biological safety and specific functionality thereof, one of the purposes of the present invention is to provide a functional composite particle and a preparation method thereof.
According to an embodiment of the present invention, the functional composite particle includes an inner core and a shell layer, wherein the inner core is consisted of functional metallic particles and has an outer surface, while the shell layer is a physical vapor deposition (PVD) ceramic layer consisted of biocompatible ceramic materials, and is attached to the outer surface of the inner core. The shell layer is a crystalline structure thereby allowing the ionic functional metallic particles to be sustained-released to the outside of the shell layer from the inner core via crystal boundaries.
Another embodiment of the present invention provides a preparation method of the functional composite particle, comprising the following steps: by means of an evaporation-condensation process, putting a solid metal block composed of functional metallic particles into a crucible, and evaporating the solid metal block by heating to a vacuum PVD process furnace for condensation; and depositing a PVD ceramic layer composed of a biocompatible ceramic material on the outer surface of the functional metallic particles in the condensed state by means of a PVD process.
Another embodiment of the present invention also provides an application of the functional composite particle. The functional composite particle is used for being coated on the surface of metal, cloth, ceramic, or plastic or implanted in metal, cloth, ceramic, or plastic.
In the embodiments of the present invention, biocompatible ceramic materials are used to cover the outside surface of the functional metallic particles which have specific functions via the PVD process so as to form functional composite particles. On the one hand, this coating structure of the functional composite particle can prevent the functional metallic particles from being oxidized by ambient oxygen, and on the other hand, the ionic state of the functional metallic particles can be sustained-released through the crystal boundaries of the shell layer, such that the action time of the functional metallic particles can be prolonged.
For a better understanding of the spirit of the present invention, the functional composite particle provided in embodiments of the present invention is further described in detail below with reference to the drawings and the specific embodiments. The advantages and features of the embodiments of the present invention would be clearer according to the following description and the claims.
It should be noted that
Specifically,
With reference to
In an embodiment of the present invention, the functional metallic particles of the inner core 11 have a particle diameter of 5 nm to 5 mm; and the shell layer 12 is a biocompatible ceramic layer consisting of a metal oxide or metal nitride composed of Zr, Ti, or Al, or a mixture of the metal oxide and the metal nitride, and has a thickness of 5 nm to 50000 nm, preferably 50 nm to 5000 nm, and surface hardness of 1000 HV to 4500 HV, preferably 3000 HV to 4000 HV.
In an embodiment of the present invention, the shell layer 12 is a biocompatible ceramic layer consisting of ZrN, TiN, AlTiN, or Al2O3.
In an embodiment of the present invention, the functional metallic particles of the inner core 11 are antibacterial metallic particles, which are Ag metallic particles, Zn metallic particles, Cu metallic particles, or a mixture thereof.
In another embodiment of the present invention, the functional metallic particles of the inner core 11 are growth-promoting metallic particles, which are Ca metallic particles, K metallic particles, Mg metallic particles, or a mixture thereof.
As shown in
The preparation method of the functional composite particl 10 shown in
by means of an evaporation-condensation process, putting a solid metal block composed of functional metallic particles into a crucible, and evaporating the solid metal block by heating to a vacuum PVD process furnace for condensation, so as to form an inner core 11 which has an outer surface 111; and depositing a PVD ceramic layer composed of a biocompatible ceramic material on the outer surface 111 of the functional metallic particles (the inner core 11) in the condensed state by means of a PVD process, to form a shell layer 12, wherein the shell layer 12 is of a crystalline structure, has a crystal boundary 121, and allows the ionic state of the functional metallic particles in the inner core 11 to be sustained-released to the outside of the shell layer 12 through the crystal boundary 121.
In an embodiment of the present invention, the particle diameter of the functional metallic particles after condensation is affected by the heating power of the heating source. In an embodiment of the present invention, the solid metal block composed of functional metallic particles is heated by using an electron gun as the heating source, wherein the current intensity of the electron gun is in a range of 60 A to 300 A, preferably 150 A to 250 A.
In an embodiment of the present invention, the step of forming the PVD ceramic layer by means of a PVD process comprises: introducing nitrogen or oxygen with a purity of 99.999% into the vacuum PVD process furnace; at a bias voltage of 0 V to 1000 V, opening a target containing a biocompatible ceramic material, with an arc current of 120 A to 200 A; and depositing a PVD ceramic layer on the outer surface of the functional metallic particles in the condensed state by means of the PVD process.
In the embodiments of the present invention, the shell layer 12 may be formed using a conventional PVD device by means of a conventional PVD process.
In the embodiments of the present invention, the functional composite particles have different functions depending on the kind of the functional metallic particles. For example, Ag metallic particles, Zn metallic particles, Cu metallic particles, or a mixture thereof correspond to antibacterial functional composite particles, and Ca metallic particles, K metallic particles, Mg metallic particles, or a mixture thereof correspond to growth-promoting functional composite particles.
Functional composite particles can be further coated on the surface of metal, cloth (cotton, nonwoven fabric, etc.), ceramic, or plastic. For example, the functional composite particles may be coated on the surface of a metal product, such as an orthopedic instrument, an artificial bone scaffold, or an artificial joint, to form an antibacterial coating or a growth-promoting coating, may be coated on the surface of a plastic product to form an antibacterial coating, and may also be coated on the surface of a nonwoven fabric to form an antibacterial coating, etc.
Moreover, the functional composite particles can also be implanted in metal, fabric, ceramic, or plastic to form a product having a specific function directly.
This is further illustrated in combination with some more preferred embodiments of the present invention as follows.
By means of an evaporation-condensation process, putting a Ag metal block into a crucible, and evaporating the Ag metal block by heating with an electron gun at a current intensity of 200 A to a vacuum PVD process furnace for condensation; and introducing nitrogen with a purity of 99.999% into the vacuum PVD process furnace; at a bias voltage of 80 V to 100 V, opening a target containing Ti, with an arc current of 120 A to 200 A; and depositing a TiN ceramic layer on the outer surface of the Ag metallic particles in the condensed state by means of the PVD process, so as to form powder of TiN—Ag composite particles, the particle diameter d1 of which is 68 nm, as shown in
By means of an evaporation-condensation process, putting a Cu metal block into a crucible, and evaporating the Cu metal block by heating with an electron gun at a current intensity of 200 A to a vacuum PVD process furnace for condensation; and
introducing nitrogen with a purity of 99.999% into the vacuum PVD process furnace; at a bias voltage of 80 V to 100 V, opening a target containing Ti, with an arc current of 120 A to 200 A; and depositing a TiN ceramic layer on the outer surface of the Cu metallic particles in the condensed state by means of the PVD process, so as to form powder of TiN—Cu composite particles, the particle diameter d2 of which is 154 nm, as shown in
By means of an evaporation-condensation process, putting a Zn metal block into a crucible, and evaporating the Zn metal block by heating with an electron gun at a current intensity of 200 A to a vacuum PVD process furnace for condensation; and
introducing oxygen with a purity of 99.999% into the vacuum PVD process furnace; at a bias voltage of 80 V to 100 V, opening a target containing Al, with an arc current of 120 A to 200 A; and depositing a TiN ceramic layer on the outer surface of the Zn metallic particles in the condensed state by means of the PVD process, so as to form powder of TiN—Zn composite particles having a growth-promoting effect.
By means of an evaporation-condensation process, putting a Mg metal block into a crucible, and evaporating the Mg metal block by heating with an electron gun at a current intensity of 200 A to a vacuum PVD process furnace for condensation; and introducing nitrogen with a purity of 99.999% into the vacuum PVD process furnace; at a bias voltage of 80 V to 100 V, opening a target containing a mixture of AlTi, with an arc current of 120 A to 200 A; and depositing an AlTiN ceramic layer on the outer surface of the Mg metallic particles in the condensed state by means of the PVD process, so as to form powder of AlTiN-Mg composite particles having a growth-promoting effect.
The functional composite particles obtained in the above embodiments 1 and 2 were respectively coated on the surfaces of plastic articles as samples of the following antibacterial effect experiments. At the same time, another identical plastic article, the surface of which was not coated with the functional composite material, was taken as a control. Test method: please refer to ISO22196:2011.
Please refer to Table I and Table II for experimental data.
Staphylococcus
aureus
Escherichia coli
Staphylococcus
aureus
Escherichia coli
Note: The values of the antimicrobial activity in the tables are the values of the antimicrobial activity of the samples with respect to the controls.
It can be known from tables I and II that compared with the plastic which is not coated with the functional composite particles provided in embodiments 1 and 2 of the present invention, the plastic coated with the functional composite particles obviously has a higher antimicrobial property.
In the embodiments of the present invention, the biocompatible ceramic material is coated on the outer surface of functional metallic particles having a specific function by means of the PVD process to form a functional composite particle. The ionic state of the functional metallic particles in the functional composite particle can be sustained-released through the crystal boundaries of the shell layer, such that the action time of the functional metallic particles can be prolonged.
The technical content and technical features of the present invention have been described in detail, but various substitutions and modifications may be made by those skilled in the art without departing from the spirit of the invention, based on the teachings and disclosures of the present invention. Therefore, the scope of protection of the present invention should not be limited to the content disclosed by the embodiments, but rather encompasses various substitutions and modifications that do not depart from the invention and are covered by the claims of this patent application.
Filing Document | Filing Date | Country | Kind |
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PCT/CN17/93391 | 7/18/2017 | WO | 00 |