Integrated femtosecond laser induced graphene oxide coating surface periodic structure method based on BiBurst mode

Abstract

The invention provides an integrated femtosecond laser induced graphene oxide coating surface periodic structure method based on a BiBurst mode, which comprises the steps of forming a graphene oxide coating, introducing a GHz frequency pulse string, further forming a laser induced periodic surface structure and the like, and belongs to the technical field of laser application. According to the invention, micro-nano structures with different periods and shapes can be flexibly realized so as to meet the requirements of different applications; the materials and the process used in the invention have advantages in environmental friendliness, can reduce the use of harmful substances, and meet the requirements of modern sustainable development.

Description

Technical Field

[0001] The invention relates to a method for forming a periodic structure on the surface of an oxide graphene coating by inducing an integrated femtosecond laser based on a BiBurst mode, and belongs to the technical field of laser application. Background Art

[0002] Graphene oxide is a sp 2 and sp 3 A material similar to graphene composed of hybrid carbon atoms, the oxygen-containing functional groups such as hydroxyl and carboxyl on its basal surface and edges make it more modifiable. Graphene oxide is a material with good biocompatibility and antibacterial properties. Graphene oxide coating has the advantages of high specific surface area and low cytotoxicity, and the rich oxygen-containing groups on the surface make it easier to be functionally modified. Graphene oxide coating cannot promote bone regeneration, and the osteogenic properties of the coating need to be improved.

[0003] Bone tissue research engineering shows that periodic nanostripes on the surface of long bones during development are beneficial to improving osteogenesis and promoting periosteal tissue formation. Therefore, a periodic structure is constructed on the surface of graphene oxide coating to improve the coating performance.

[0004] Laser processing has the advantages of high efficiency, high precision, cleanliness, and controllability, and is widely used in many fields. Ultrafast lasers have high peak energy, low heat accumulation, and processing characteristics of extremely small resolution and extremely small scale regulation. With the development of ultrafast laser processing technology, by using femtosecond lasers, high-precision control of the micro-nano morphology and chemical composition of the graphene oxide surface can be achieved, and efficient and accurate periodic structure processing can be achieved on the graphene oxide surface. Graphene oxide coatings with specific groups and surface morphologies can be accurately and controllably prepared, while meeting the antibacterial and osteogenic performance requirements of implants, and improving their application in biomedicine.

[0005] In the prior art, the periodic structure of the surface of graphene oxide coating prepared by technology results in excessive stripe period and depth that damages the substrate, precise control of oxygen-containing functional groups, and surface defects common in traditional processing.

[0006] Therefore, there is an urgent need in the art for a method for inducing periodic structures on the surface of graphene oxide coatings using an integrated femtosecond laser based on the BiBurst mode. Summary of the invention

[0007] The purpose of the present invention is to solve the problems of excessive stripe period and depth that damage the substrate, precise control of oxygen-containing functional groups, and common surface defects in traditional processing caused by the prior art technology for preparing the periodic structure of the surface of graphene oxide coating.

[0008] In order to achieve the purpose of solving the above problems, the technical solution adopted by the present invention is to provide a method for integrating femtosecond laser-induced periodic structure on the surface of graphene oxide coating based on BiBurst mode, comprising the following steps:

[0009] Step 1: Use a coating machine to evenly coat the graphene oxide aqueous solution on the titanium alloy substrate and dry it to form a graphene oxide coating.

[0010] Step 2: Adjust the number of MHz-Burst and GHz-Burst pulse trains of the laser to form a pulse train mode (BiBurst mode) containing sub-pulse trains, increase the pulse frequency of the femtosecond laser processing system from KHz to MHz, and introduce a GHz frequency pulse train.

[0011] Step 3: Apply a femtosecond laser in BiBurst mode to the surface of the graphene oxide coating to form a laser-induced periodic surface structure (LIPSS).

[0012] Preferably, in step 1, the graphene oxide coating is evenly coated on the surface of the titanium alloy.

[0013] Preferably, in step 2, the laser used is an integrated femtosecond laser.

[0014] Preferably, the wavelength of the integrated femtosecond laser is 1030 nm.

[0015] Preferably, the integrated femtosecond laser has a pulse train-containing sub-pulse train function (BiBurst mode).

[0016] Preferably, the integrated femtosecond laser generates a MHz-Burst pulse train including a sub-pulse train (BiBurst) by forming a pulse train, and generates a GHz-Burst pulse train therein.

[0017] Preferably, in step 2, the pulse spacing in the MHz-Burst pulse train is 15 ns, and the adjustable number of pulses is 1 to 10.

[0018] Preferably, in step 2, the pulse spacing in the GHz-Burst pulse train is 400 ps to 480 ps, ​​and the number of tunable pulses is between 1 and 10.

[0019] Preferably, in step 3, the graphene oxide coating is placed on a motion platform of a femtosecond laser processing system, the number of MHz-Burst pulse trains and GHz-Burst pulse trains is set, and the graphene oxide coating on the titanium alloy is processed.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention can generate multiple sub-pulses in a single laser pulse, thereby completing more complex processing in a shorter time and improving energy utilization and processing speed.

[0022] (2) The present invention provides better pulse interval control, making the energy distribution during the processing more uniform, thereby constructing a more refined and uniform periodic structure on the graphene oxide coating, avoiding the surface defects commonly seen in traditional processing.

[0023] (3) The present invention can flexibly realize micro-nano structures of different periods and shapes to meet the needs of different applications; the materials and processes used in the present invention have advantages in environmental friendliness, can reduce the use of harmful substances, and meet the needs of modern sustainable development.

[0024] (4) The present invention does not require a vacuum experimental environment.

[0025] (5) The present invention is not only applicable to graphene oxide, but can also be extended to other two-dimensional materials and nanomaterials. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a flowchart of the method proposed by the present invention.

[0027] Figure 2 Flowchart for preparing graphene oxide coating on titanium alloy substrate.

[0028] Figure 3 Schematic diagram of the femtosecond laser processing system.

[0029] Figure 4 Schematic diagram of BiBurst mode.

[0030] Figure 5 This is a scanning electron microscope image of the laser-induced periodic surface structure.

[0031] Figure numbers: 1-titanium alloy, 2-spinning machine, 3-graphene oxide aqueous solution, 4-graphene oxide coating, 5-femtosecond laser source, 6-half-wave plate, 7-polarizer, 8-filter, 9-mirror, 10-shutter, 11-scanning head, 12-motion platform, 13-computer. DETAILED DESCRIPTION

[0032] In order to make the present invention more clearly understood, a preferred embodiment is described in detail with reference to the accompanying drawings as follows:

[0033] like Figure 1-5As shown, the present invention provides a method for forming a periodic structure on the surface of graphene oxide coating by inducing femtosecond laser in BiBurst mode, and generates periodic nano-stripes with specific functional groups on the surface of graphene oxide coating by adjusting the laser pulse and scanning speed, namely laser induced periodic surface structure, LIPSS. The use of BiBurst mode makes the energy distribution of pulses in the processing process more uniform, thereby constructing a more delicate, uniform and periodic structure containing specific functional groups. Figure 1 This is a flow chart of the method proposed by the present invention, and the specific steps are as follows:

[0034] Step 1: Use a coating machine to evenly coat the graphene oxide aqueous solution on the titanium alloy substrate and dry it to form a graphene oxide coating.

[0035] Step 2: Adjust the number of MHz-Burst and GHz-Burst pulse trains to form a pulse train mode (BiBurst mode) containing sub-pulse trains, increase the pulse frequency of the femtosecond laser processing system from KHz to MHz, and introduce a GHz frequency pulse train.

[0036] Step 3: Apply a femtosecond laser in BiBurst mode to the surface of the graphene oxide coating to form a laser induced periodic surface structure (LIPSS).

[0037] In step 1, the titanium alloy sheet is surface polished and ultrasonically cleaned, and then a graphene oxide aqueous solution is coated on the surface of the titanium alloy, and a uniformly coated graphene oxide coating is formed after drying. The process is as follows: Figure 2 shown.

[0038] The laser used is an integrated femtosecond laser.

[0039] The wavelength of the integrated femtosecond laser is 1030nm.

[0040] The laser emitted by the integrated femtosecond laser is linearly polarized in a vertical direction.

[0041] In step 2, a single pulse is tuned into a MHz-Burst and a GHz-Burst pulse train to form a BiBurst pulse train. The process is as follows: Figure 4 shown.

[0042] In step 2, the pulse interval in the MHz-Burst pulse train is 15 ns, and the number of pulses can be adjusted from 1 to 10.

[0043] In step 2, the pulse interval in the GHz-Burst pulse train is 400 ps to 480 ps, ​​and the number of tunable pulses is between 1 and 10.

[0044] In step three, the graphene oxide coating on the titanium alloy substrate is placed on a motion platform (such as Figure 3 As shown), the number of MHz-Burst and GHz-Burst pulse trains is set to process the graphene oxide coating to generate a laser-induced periodic surface structure with specific functional groups (such as Figure 5 shown).

[0045] By tuning the values ​​of MHz and GHz pulses, a pulse sequence containing sub-pulses is generated within the pulse train, so that the energy of the femtosecond laser is more evenly distributed on the coating, a more refined and uniform periodic structure is constructed, and micro-nano structures with different periods and shapes are flexibly realized. At the same time, the chemical composition of the coating is regulated with high precision to prepare a graphene oxide coating with specific groups and surface morphology.

[0046] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and equivalent changes made by using the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for forming a periodic structure on the surface of a graphene oxide coating by an integrated femtosecond laser-induced graphene oxide coating based on a BiBurst mode, characterized in that: The following steps are involved: Step 1: Use a coating machine to evenly coat the graphene oxide aqueous solution on the titanium alloy substrate and dry it to form a graphene oxide coating. Step 2: Adjust the number of MHz-Burst and GHz-Burst pulse trains of the laser to form a pulse train mode containing sub-pulse trains, namely BiBurst mode, increase the pulse frequency of the femtosecond laser processing system from KHz to MHz, and introduce a GHz frequency pulse train. Step 3: Apply a femtosecond laser in BiBurst mode to the surface of the graphene oxide coating to form a laser-induced periodic surface structure.

2. The method for forming a periodic structure on the surface of an integrated femtosecond laser-induced graphene oxide coating based on the BiBurst mode according to claim 1, characterized in that: In the step 1, the graphene oxide coating is evenly coated on the surface of the titanium alloy.

3. The method for forming a periodic structure on the surface of an integrated femtosecond laser-induced graphene oxide coating based on the BiBurst mode according to claim 1, characterized in that: In the step 2, the laser used is an integrated femtosecond laser.

4. The method for forming a periodic structure on the surface of an integrated femtosecond laser-induced graphene oxide coating based on the BiBurst mode according to claim 3, characterized in that: The wavelength of the integrated femtosecond laser is 1030nm.

5. The method for forming a periodic structure on the surface of an integrated femtosecond laser-induced graphene oxide coating based on the BiBurst mode according to claim 3, characterized in that: The integrated femtosecond laser has a pulse train-containing sub-pulse train function.

6. The method for forming a periodic structure on the surface of an integrated femtosecond laser-induced graphene oxide coating based on BiBurst mode according to claim 3, characterized in that: The integrated femtosecond laser generates a MHz-Burst pulse train including sub-pulse trains by forming a pulse train, and generates a GHz-Burst pulse train therein.

7. The method for forming a periodic structure on the surface of an integrated femtosecond laser-induced graphene oxide coating based on the BiBurst mode according to claim 1, characterized in that: In the step 2, the pulse spacing in the MHz-Burst pulse train is 15ns, and the number of pulses can be adjusted from 1 to 10.

8. The method for forming a periodic structure on the surface of an integrated femtosecond laser-induced graphene oxide coating based on the BiBurst mode according to claim 1, characterized in that: In the step 2, the pulse spacing in the GHz-Burst pulse train is 400ps to 480ps, and the number of tunable pulses is between 1 and 10.

9. The method for forming a periodic structure on the surface of an integrated femtosecond laser-induced graphene oxide coating based on the BiBurst mode according to claim 1, characterized in that: In the step 3, the graphene oxide coating is placed on a motion platform of a femtosecond laser processing system, the number of MHz-Burst pulse trains and GHz-Burst pulse trains is set, and the graphene oxide coating on the titanium alloy is processed.

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