Preparation of chemically stable super-hydrophobic wood
阅读说明：本技术 一种化学稳定的超疏水木材的制备 (Preparation of chemically stable super-hydrophobic wood ) 是由 沈华杰 杨玉山 周晓剑 邱坚 于 2019-04-10 设计创作，主要内容包括：本发明提出一种化学稳定的超疏水木材的制备,属于木材基体表面功能化改性技术领域。具体包括几个步骤：(1)用Stber法合成了二氧化硅微球,通过溶液自组装低表面能物质得到改性二氧化硅纳米粒子；(2)制备PDMS体混合液；(3)在木材表面上交替滴涂500nm和100nm粒径粒径的SiO2,获得了微纳结构表面；(4)再滴涂PDMS层连接。本发明提供了制备一种化学稳定的超疏水木材的制备,改变了木材表面的亲水性能,有效的防止腐蚀性液体的侵蚀,而且具有良好的化学稳定性。本发明解决了木材表面改性修饰稳定性差的问题。此方法制备简单,成本低廉,延长了木材的使用寿命,缓解木材供需矛盾,具有广阔的应用前景。(The invention provides a preparation method of chemically stable super-hydrophobic wood, and belongs to the technical field of surface functional modification of wood substrates. The method specifically comprises the following steps: (1) synthesizing silicon dioxide microspheres by a Stber method, and self-assembling a low-surface-energy substance by a solution to obtain modified silicon dioxide nano particles; (2) preparing PDMS body mixed liquid; (3) alternately dripping SiO2 with the grain diameter of 500nm and 100nm on the surface of the wood to obtain a micro-nano structure surface; (4) and then drop-coating the PDMS layer connection. The invention provides a method for preparing chemically stable super-hydrophobic wood, which changes the hydrophilic property of the surface of the wood, effectively prevents the corrosion of corrosive liquid and has good chemical stability. The invention solves the problem of poor stability of wood surface modification. The method is simple in preparation and low in cost, prolongs the service life of the wood, relieves the contradiction between supply and demand of the wood, and has wide application prospect.)
1. Preparation of chemically stable superhydrophobic wood, characterized by: the method specifically comprises the following steps:
(1) the monodisperse nano SiO is prepared by a Stber method2Microsphere preparation: 3.8ml of tetraethyl orthosilicate (TEOS) was added to 5.7 ml of ammonia water in 144ml of absolute ethanol; magnetically stirring for 24 hours at room temperature; repeatedly centrifuging and separating by using absolute ethyl alcohol to purify the silicon dioxide microspheres;
(2) the modification is carried out by growing low surface energy substances on the silicon dioxide spheres by the method of solution self-assembly in (1): suspending 0.3g of nano silicon dioxide in 50 ml of OTS benzene solution with the volume ratio of 0.6%, performing ultrasonic treatment for 20min, aging for 2h at room temperature, and curing for 24h at 100 ℃; purifying by repeated centrifugation, and collecting modified silica nanoparticles;
(3) preparation of crosslinked PDMS mixtures: the volume ratio of the main agent PDMS to the curing agent is 10: 1;
(4) preparing a super-hydrophobic wood surface: 100nm modified SiO280 mg，500nmSiO2100 mg, respectively suspended in 40ml of ethanol.
2. The preparation of chemically stable superhydrophobic wood of claim 1, wherein: the particle size of the silica microspheres purified by repeated centrifugal separation with absolute ethyl alcohol in the step (1) is 500 +/-10 nm and 100 +/-10 nm as determined by a scanning electron microscope.
3. The preparation of chemically stable superhydrophobic wood of claim 1, wherein: the low surface energy substances in the step (2) are OTS and FAS-17.
4. The preparation of chemically stable superhydrophobic wood of claim 1, wherein: the curing agent in the step (3) is 184 silicone rubber.
5. The preparation of chemically stable superhydrophobic wood of claim 1, wherein: the step (4) is carried out by mixing 500 nmH and 100nm SiO2The mixed liquid drop coating speed is 1-3 drops/s.
6. The preparation of chemically stable superhydrophobic wood of claim 1, wherein: the step (4) is to modify SiO by self-assembly on a wood substrate2Particles of since SiO2Poor compatibility with PDMS, organic modification of SiO2Nanoparticle formation of flexible SiO2Network and covalent bonding PDMS molecules are decorated to prepare the super-hydrophobic surface, and the used organic solvent is n-hexane.
7. The preparation of chemically stable superhydrophobic wood of claim 1, wherein: the step (4) is carried out by preparing modified SiO on the surface of the wood before preparing the laminated structure2And a PDMS micro-particle film; the samples were all aged at 60 ℃ for 24h and cured at 140 ℃ for 24 h.
8. Super-hydrophobic wood having mechanical stability and abrasion resistance is prepared according to the method of any one of claims 1 to 7.
Technical Field
The invention belongs to the field of solid surface wettability technology and functional modification, and particularly relates to preparation of chemically stable super-hydrophobic wood.
Background
The wettability of the solid surface has important application value in both academic research and practical application. In nature, many surfaces, including the lotus leaf and the water strider leg, have water contact angles above 150 ° and are referred to as superhydrophobic surfaces. The self-cleaning behavior of these surfaces, known as the "lotus effect", is believed to be caused by the hierarchical structure and layering of low surface energy materials. Methods for preparing superhydrophobic surfaces are numerous, such as templating, soft printing, chemical deposition, colloidal self-assembly, deposition, sol-gel, and the like. Wherein the self-assembly method of the colloid from bottom to top isA simple and inexpensive technique. Materials such as silicon, silica particles, etc. have been used to prepare surfaces having dual structure roughness. However, this method is difficult to achieve mass production. Recently, young et al have proposed a method for preparing a superhydrophobic surface based on inorganic particles and alkyl-PDMS. Firstly, CaCO is sprayed on the glass3/SiO2The particles were mixed and then PDMS was self-assembled on the glass surface. However, the stable PDMS-based superhydrophobic surface is prepared by methods such as a template method, pulse laser treatment, a soft printing technology and the like, the method is limited by expensive equipment and complicated procedures, and the structure of the superhydrophobic surface is very fragile, so that the scale of application is hindered. The current super-hydrophobic material not only has harsh experimental conditions, but also has low strength of the surface nano/micro nano structure, easy aging, easy abrasion and short service life. According to the invention, the silica nanoparticles and PDMS copolymer are dripped on the surface of wood to obtain the wood-based super-hydrophobic surface. Compared with the prior art, the method has the advantages of time saving, low cost and simple and easy preparation technology. Meanwhile, the silica particles are used for surface modification, which is beneficial to forming stable super-hydrophobic wood and prolonging the service life of the wood. Therefore, the development of chemically stable superhydrophobic wood technology is the key point for the wide popularization and application of wood.
Disclosure of Invention
Aiming at the problems in the prior art, the invention aims to provide a preparation method of chemically stable super-hydrophobic wood, which can realize the chemical stability and super-hydrophobic property of the surface of the wood, change the hydrophilicity of the surface of the wood and effectively prevent the abrasiveness and the easy aging property of the wood. The method is simple in operation, low in cost, green, environment-friendly and sustainable in development.
Therefore, the invention provides a preparation method of chemically stable super-hydrophobic wood, which is characterized by comprising the following steps: the method specifically comprises the following steps:
(1) the monodisperse nano SiO is prepared by a Stber method2Microsphere preparation: in 144ml of absolute ethanol, 3.8ml of tetraethyl orthosilicate (TEOS) was added to 5.7 ml of aqueous ammonia. Magnetically stir at room temperature for 24 h. Purification of silica microspheres by repeated centrifugation with absolute ethanol；；
(2) Growing Octadecyl Trichlorosilane (OTS) on the silicon dioxide spheres by a method of self-assembly of the solution in (1) for modification: 0.3g of nano-silica is suspended in 50 ml of OTS benzene solution with the volume ratio of 0.6 percent, ultrasonic treatment is carried out for 20min, aging is carried out for 2h at room temperature, and curing is carried out for 24h at 100 ℃. Collecting and purifying the modified silicon dioxide super-hydrophobic nano particles by a repeated centrifugation method;
(3) preparation of crosslinked PDMS mixtures: the volume ratio of the main agent PDMS to the curing agent 184 silicon rubber is 10: 1;
(4) preparing a super-hydrophobic wood surface: 100nm modified
In the preparation method, preferably, the particle size of the silica nanoparticle subjected to repeated centrifugal separation and purification is 500 +/-10 nm or 100 +/-10 nm.
In the above-mentioned preparation method, preferably, the low surface energy substance is OTS and FAS-17.
In the above preparation method, preferably, the curing agent is 184 silicone rubber.
In the preparation method, preferably, the speed of applying the mixed liquid drops of 500 nmH and 100nm SiO2 on the surface of the wood is 1-3 drops/s.
In the preparation method, preferably, the modified SiO2 particles are self-assembled on the wood substrate, because the compatibility of SiO2 and PDMS is poor, the organic modified SiO2 nanoparticles are used to form a flexible SiO2 network and covalently bond PDMS molecules for decoration, so that a super-hydrophobic surface is prepared, and the used organic solvent is n-hexane.
In the above preparation method, preferably, the modified SiO2 and PDMS microparticle films are prepared on the wood surface. The samples were all aged at 60 ℃ for 24h and cured at 140 ℃ for 24 h.
The invention has the advantages that:
1. the invention provides a preparation method of chemically stable super-hydrophobic wood, which adopts a simple dripping method to modify micro-nano modified SiO2The microspheres are coated on the surface of the wood, and the required period is about 48 hours.
2. The invention provides a preparation method of chemically stable super-hydrophobic wood, which adopts a simple dropping coating method to prepare the super-hydrophobic wood with a water contact angle of 158 degrees and a sliding angle of 6 degrees on the surface of the wood. Thereby imparting superhydrophobic properties to the wood.
3. The invention provides a preparation method of chemically stable super-hydrophobic wood, and a super-hydrophobic coating on the surface of the wood can effectively prevent moisture from entering the wood, namely SiO2The surface modification of the microspheres improves the dispersibility of particles, improves the compatibility of the particles and PDMS, finally enhances the strength of the nano structure on the surface of the wood, improves the dimensional stability of the wood and enlarges the application range of the wood.
4. The invention provides a preparation method of chemically stable super-hydrophobic wood, which researches that the super-hydrophobic surface has better chemical stability through a sand paper abrasion test on the surface of the wood by adopting a simple dropping coating method, and the super-hydrophobic wood still keeps super-hydrophobicity under the action of a corrosive solution.
5. The invention provides a preparation method of chemically stable super-hydrophobic wood, which does not need expensive and complex special equipment.
Drawings
In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.
FIG. 1: EDS spectrogram of the chemically stable super-hydrophobic wood surface prepared by the method.
FIG. 2: the chemically stable super-hydrophobic wood prepared by the method is used for preparing a high-power electron microscope image of the surface of the chemically stable super-hydrophobic wood.
FIG. 3: the static water contact angle graph of the chemically stable super-hydrophobic wood surface and the wood element surface obtained by the method is adopted.
FIG. 4: the chemically stable super-hydrophobic wood obtained by the method has a macroscopic picture of salt water, milk, tea and vinegar after sand paper test on the surface of the chemically stable super-hydrophobic wood.
FIG. 5: the static tea water contact angle graph of the chemically stable super-hydrophobic wood surface obtained by the method is adopted.
FIG. 6: the static vinegar contact angle graph of the chemically stable super-hydrophobic wood surface obtained by the method is adopted.
FIG. 7: the static coffee contact angle graph of the chemically stable super-hydrophobic wood surface obtained by the method is adopted.
FIG. 8: the chemically stable super-hydrophobic wood surface static salt water contact angle graph obtained by the method is adopted.
Detailed description of the preferred embodiments
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.
The experimental procedures in the following examples are conventional unless otherwise specified.
The test materials used in the following examples were purchased from a conventional reagent store unless otherwise specified.
In the quantitative tests in the following examples, three replicates were set, and the data are the mean or the mean ± standard deviation of the three replicates.
The invention provides a preparation method of chemically stable super-hydrophobic wood, which specifically comprises the following steps:
(1) the monodisperse nano SiO is prepared by a Stber method2Microsphere preparation: at 144mlTo the absolute ethanol of (3.8 ml) was added Tetraethoxysilane (TEOS) to 5.7 ml of ammonia water. Magnetically stir at room temperature for 24 h. Repeatedly centrifuging and separating by using absolute ethyl alcohol to purify the silicon dioxide microspheres;
(2) growing Octadecyl Trichlorosilane (OTS) on the silicon dioxide spheres by a method of self-assembly of the solution in (1) for modification: 0.3g of nano-silica is suspended in 50 ml of OTS benzene solution with the volume ratio of 0.6 percent, ultrasonic treatment is carried out for 20min, aging is carried out for 2h at room temperature, and curing is carried out for 24h at 100 ℃. Collecting and purifying the modified silicon dioxide super-hydrophobic nano particles by a repeated centrifugation method;
(3) preparation of crosslinked PDMS mixtures: the volume ratio of the main agent PDMS to the curing agent 184 silicon rubber is 10: 1;
(4) preparing a super-hydrophobic wood surface: 100nm modified
The stable wear-resistant SiO prepared in this example was analyzed by Scanning Electron Microscopy (SEM)2Micro-morphology of super-hydrophobic wood. In addition, to further verify the properties of the wood obtained in the examples of the invention, it was subjected to stability and hydrophobicity tests:
1. the results of chemical element analysis of chemically stabilized superhydrophobic wood are shown in FIG. 1
The chemically stable super-hydrophobic wood surface obtained from the figure contains Si;
2. the micro-topography of the chemically stable superhydrophobic wood surface is shown in FIG. 2
The chemically stable super-hydrophobic wood surface structure can be obtained from fig. 2, and the micro-nano structure morphology of the rose petal-like surface on the surface can be clearly seen, so that the super-hydrophobic effect is achieved;
3. contact angles of chemically stabilized superhydrophobic wood surfaces are shown in fig. 3
The contact angles of the original wood obtained from the figure 3 are all less than 20 degrees, so that the hydrophilic characteristic is presented; and the contact angles of the chemically stable super-hydrophobic wood surface are all larger than 150 degrees, so that the super-hydrophobic characteristic is presented.
4. The stable abrasion resistance characteristics of the chemically stable superhydrophobic wood surface are shown in fig. 4
From FIG. 3, SiO2The superhydrophobic wood sample was placed on a 300 grit sandpaper and pressed against a 150 gram weight and moved 20 cm along the ruler, and recorded as a cycle. After a sand paper abrasion one-cycle test, the wettability of 4 common liquids (including salt water, tea, milk and vinegar) on the surface is measured, different liquid drops on the surface are similar to a sphere, and contact angles are all larger than 150 degrees, so that the stable abrasion resistance characteristic is realized.
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