Composite self-cleaning roller shutter fabric and preparation method thereof

Abstract

The invention belongs to the field of roller shutter fabrics, and particularly relates to a composite self-cleaning roller shutter fabric and a preparation method thereof. The method comprises the following steps: 1) pretreating raw materials to prepare a base material; (2) carrying out structure optimization on the surface of the base material by adopting a chemical vapor deposition method to prepare an optimized base material; and (3) annealing the optimized base material at low temperature to prepare the composite self-cleaning roller shutter fabric. The transverse nanotube formed by chemical vapor deposition guides water drops to rapidly migrate in a specific direction through surface energy gradient difference, self-cleaning is realized, cycloaddition transition enables surface molecules to form a stable Si-O-Si cross-linked network, surface free energy is remarkably reduced, hydrophobic durability is enhanced, meanwhile, a polyester / polyamide base material provides flexibility, and the self-cleaning performance is improved. And through chemical bond combination with the chemical vapor deposition layer, the problem of interface stripping is avoided.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of roller blind fabric, and particularly relates to a composite self-cleaning roller blind fabric and a preparation method thereof. BACKGROUND

[0002] In the field of traditional roller blind fabric, the self-cleaning function mainly depends on the surface coating technology of fluorocarbon compounds or silicon resins. However, this dependence has several significant defects: first, the durability is insufficient. Since the coating is easily affected by mechanical friction and ultraviolet radiation in practical application, the coating peels off, thereby reducing the hydrophobic property of the fabric and seriously affecting the self-cleaning effect. Second, the self-cleaning efficiency is not high. The static hydrophobic surface has obvious deficiencies in guiding the directional migration of water droplets, and cannot quickly and effectively remove stains with water droplets, resulting in serious stain residue problem, which is difficult to meet the ideal self-cleaning demand. Finally, there is a deficiency in environmental protection. Some coating materials contain organic solvents or heavy metal components, which not only have adverse effects on the ecological environment, but also may pose a potential threat to human health in the long-term contact process. The current market urgently needs a self-cleaning roller blind fabric combining a new preparation process and environmentally friendly materials to achieve efficient and durable hydrophobic properties and meet the industry development and actual user demand. SUMMARY

[0003] The technical scheme of the present application aims to solve the technical problems of poor durability, low hydrophobic efficiency and poor self-cleaning effect of traditional self-cleaning roller blind fabric, and provides a composite self-cleaning roller blind fabric and a preparation method thereof.

[0004] The main purpose of the present application is: 1. Strengthening the weather resistance of the fabric.

[0005] 2. Optimizing the self-cleaning effect.

[0006] 3. Enhancing the surface hydrophobic effect of the fabric.

[0007] To achieve the above purpose, the present application adopts the following technical scheme.

[0008] A preparation method of a composite self-cleaning roller blind fabric, the method comprising: 1) pretreating raw materials to obtain a base material.

[0009] 2) optimizing the structure of the base material surface by chemical vapor deposition to obtain an optimized base material.

[0010] 3) annealing the optimized base material at low temperature to obtain a composite self-cleaning roller blind fabric.

[0011] As a preferred, the raw material of step 1) is polyester and / or polyamide fiber fabric, the thickness is 0.2-0.5 mm, and the density is ≥150 g / m 2 .

[0012] Preferably, the pretreatment in step 1 is oxygen plasma activation, which is performed under the following conditions: oxygen atmosphere, pressure of 30-50 Pa, gas flow of 20-40 sccm, power of 80-120 W, and treatment time of 3-10 min using a radio frequency plasma generator.

[0013] Preferably, the precursor in the chemical vapor deposition method in step 2 is hexamethyldisiloxane, the flow rate is 5-15 sccm, the carrier gas is nitrogen, the flow rate is 40-60 sccm, the deposition is performed at a temperature of 200-220 ℃ and a pressure of 10-50 Pa for 30-60 min.

[0014] Preferably, the low-temperature annealing in step 3 is performed under the following conditions: nitrogen atmosphere, temperature of 80-120 ℃, and holding time of 30-60 min.

[0015] A composite self-cleaning roller blind fabric.

[0016] In the technical solution of the present application, the core lies in the use of chemical vapor deposition to construct a transverse nanoscale pipeline structure on the surface of the fabric. The construction process includes multiple fine and interrelated steps, each of which plays a decisive role in achieving excellent performance of the fabric.

[0017] First, the surface activation treatment of the raw material is the key starting link of the entire process. In this stage, hydroxyl (-OH) and carboxyl (-COOH) groups are introduced on the surface of the raw material. The introduction of these active groups significantly enhances the adhesion of related substances to the surface of the fabric during the subsequent chemical vapor deposition process, laying a solid foundation for subsequent precise deposition and structure construction.

[0018] Subsequently, the chemical vapor deposition process is used to deposit siloxane fragments on the surface of the activated substrate in a targeted manner. This process is not random, but strictly follows the crystal lattice direction of the substrate surface for orderly arrangement. Siloxane fragments are deposited along the crystal lattice direction, and finally form a semi-open transverse nanotube array structure on the surface of the fabric. In this structure, the methyl groups are arranged outward in an orderly manner, forming an outer layer with low surface energy characteristics. At the same time, through the complex chemical reaction mechanism of cycloaddition transition, a stable hydrophobic network structure is formed. This network not only enhances the interfacial bonding force between the parts, but also makes the entire structure more stable. Specifically, the siloxane fragments undergo condensation reaction with the pre-introduced hydroxyl (-OH) groups on the surface of the substrate to form Si-O-C covalent bonds, which tightly connect the siloxane to the substrate. In addition, the siloxane molecules are further cross-linked through dehydrogenation reaction to form a three-dimensional Si-O-Si cross-linked network, greatly improving the stability and functionality of the overall structure.

[0019] After the above deposition process is completed, a low-temperature annealing process is immediately carried out. This step is crucial for stabilizing the surface structure and improving the mechanical properties of the fabric. By precisely controlling the annealing temperature and time, the microstructure inside the fabric is further optimized, ensuring that it not only has excellent hydrophobic properties but also meets the requirements for mechanical strength and other aspects in actual applications.

[0020] After a series of precise operations through the chemical vapor deposition process, the transverse nanochannels successfully constructed on the substrate surface exhibit unique physical and chemical properties. Based on the principles of surface energy gradient and capillary force, these nanochannels can guide water droplets to quickly migrate along a specific direction, thereby realizing the function of active self-cleaning. The nanochannels are arranged in a specific direction, forming periodic surface energy difference regions on the fabric surface. Specifically, the high surface energy region is located at the bottom of the channel, while the low surface energy region is at the top of the channel. When a water droplet contacts the fabric surface, the high surface energy region rapidly absorbs water into the channel due to strong capillary force, while the low surface energy region plays a pushing role, promoting the water to quickly migrate along the channel direction. In the process of water droplet migration, it naturally carries the particulate contaminants attached to the fabric surface, like a rolling broom, achieving efficient "rolling self-cleaning" effect.

[0021] In the present invention, the Si-O-Si crosslinking network formed by cycloaddition transition plays a crucial role in the entire technical solution. This crosslinking network not only significantly reduces the free energy of the fabric surface, making it difficult for water to adhere to it, but also combines with the polyester / polyamide substrate through strong chemical bonds. Among them, the Si-O-C bond serves as a bridge connecting the hydrophobic layer and the substrate, tightly combining the two together, effectively avoiding the interface peeling problem that is prone to occur in traditional coatings. At the same time, in the three-dimensional Si-O-Si crosslinking network formed by the dehydrogenation reaction between siloxane molecules, the Si-O-Si network has high bond energy, giving the fabric excellent ultraviolet and chemical corrosion resistance. This series of characteristics collectively ensures that the hydrophobic properties of the fabric remain stable and reliable during long-term use, providing strong protection for its application in various complex environments.

[0022] The advantages of the present invention are: 1) The transverse nanochannels formed by chemical vapor deposition guide water droplets to quickly migrate along a specific direction through the difference in surface energy gradient, realizing self-cleaning; 2) The cycloaddition transition causes the surface molecules to form a stable Si-O-Si crosslinking network, significantly reducing the surface free energy and enhancing the hydrophobic durability; 3) The polyester / polyamide substrate provides flexibility and is combined with the chemical vapor deposition layer through chemical bonds, avoiding the problem of interface peeling. DETAILED DESCRIPTION

[0023] The present application will be further described in connection with the following detailed description of specific embodiments. Those skilled in the art will be able to implement the present application based on the description and drawings. Furthermore, the embodiments of the present application described herein are generally only exemplary embodiments of the present application and are not exhaustive of all embodiments of the present application. Therefore, all other embodiments of the present application that are obtained based on the embodiments of the present application described herein without creative work should be within the scope of the present application.

[0024] Unless otherwise specified, the raw materials used in the embodiments of the present application are commercially available or available to those skilled in the art. Unless otherwise specified, the methods used in the embodiments of the present application are methods mastered by those skilled in the art.

[0025] Example 1: A preparation method of a composite self-cleaning roller blind fabric, the method comprising: 1) polyamide fiber fabric with a thickness of 0.5 mm and a density of 150 g / m 2 is subjected to oxygen plasma activation, and is treated by a radio frequency plasma generator under the following environmental conditions: oxygen atmosphere, pressure of 30 Pa, gas flow of 20 sccm, power of 80 W, and treatment time of 10 min, to obtain a substrate.

[0026] 2) The substrate surface is subjected to structure optimization by chemical vapor deposition, using hexamethyldisiloxane as the precursor, with a flow rate of 5 sccm and nitrogen as the carrier gas, with a flow rate of 40 sccm, under the following environmental conditions: temperature of 200 ℃, pressure of 10 Pa, and deposition time of 60 min, to obtain an optimized substrate.

[0027] 3) The optimized substrate is subjected to low-temperature annealing under the following environmental conditions: nitrogen atmosphere and temperature of 80 ℃, with a holding time of 60 min, to obtain a composite self-cleaning roller blind fabric.

[0028] The roller blind fabric prepared in this example is subjected to performance testing, and the specific characterization results are as follows.

[0029] Mechanical property testing: The fabric prepared in this example is subjected to mechanical property testing according to the ASTM D5034 testing method, using a universal material testing machine, taking 5 test samples along the warp direction of the fabric, stretching the test samples to break at a rate of 50 mm / min, and recording the maximum load and elongation.

[0030] Abrasion resistance testing: The fabric prepared in this example is cut into 5 circular test samples with a diameter of 38 mm, a pressure of 12 kPa is applied, wool felt is used as the friction medium, and the mass loss rate of the fabric after 5000 times of friction is tested.

[0031] Chemical stability test: The fabric prepared in this example was cut into 10 test samples of 100 mm x 100 mm, divided into two groups, and immersed in acidic and basic reagents for 24 hours, respectively. After taking out, rinse with deionized water for 3 times, dry and test the tensile strength retention rate. The acidic reagent is 5% sulfuric acid solution, and the basic reagent is 5% sodium hydroxide solution.

[0032] Hydrophobicity test: The fabric prepared in this example was cut into 20 mm x 20 mm test samples, and the test samples were fixed on the contact angle measuring instrument stage. 5 μL of deionized water was added dropwise, and the droplet morphology was recorded by a high-speed camera. The contact angle (θ) and roll angle (α) were calculated.

[0033] Self-cleaning efficiency test: The fabric prepared in this example was cut into 20 mm x 20 mm test samples, and carbon black dust with a particle size of 10 μm was prepared. The test sample was placed on a 5° fixed angle inclined platform, and a water dripping device with a flow rate of 0.5 mL / s was set at the upper end 10 cm. The dust was evenly spread on the surface of the test sample at a rate of 0.1 g / m 2 and left for 5 minutes. A constant flow rate of water was dripped, and the time for the dust to be completely washed away was recorded.

[0034] Interface bonding strength test: Scratch test (ASTM D7027) was used, with a 200 μm radius diamond indenter applying a load of 0-50 N. The critical force for hydrophobic layer peeling was recorded.

[0035]

[0036] Analyzing the above characterization results, in terms of mechanical properties, the tensile strength of the fabric along the warp and weft directions reached 34.3 MPa, and the elongation at break was 112.4 %, indicating that the fabric had good strength and toughness, and could meet the mechanical requirements in actual application. In the abrasion resistance test, the mass loss rate of the fabric after 5000 times of friction was only 3.7 %, showing excellent wear resistance, ensuring that the fabric would not be easily worn out during long-term use. In terms of chemical stability, the tensile strength retention rate of the fabric after immersion in acidic and basic reagents for 24 hours was 94.3 % and 95.2 % respectively, indicating that the fabric had good chemical stability and could maintain stable performance in various chemical environments. In the hydrophobicity test, the contact angle of the fabric reached 157.5°, and the roll angle was 8.3°, showing excellent hydrophobic performance. Water droplets were difficult to adhere to the surface of the fabric and easily rolled away with stains, achieving high-efficiency self-cleaning effect. The self-cleaning efficiency test results showed that under the condition of constant flow rate of water dripping, the fabric could completely wash away the dust from the surface in only 6.2 seconds, indicating that the fabric had high-efficiency self-cleaning ability. In addition, the interface bonding strength test results showed that the critical force for hydrophobic layer peeling was 14.7 N, indicating that the hydrophobic layer was tightly bonded with the substrate and was not easy to peel off.

[0037] Example 2: A method for preparing a composite self-cleaning roller shutter fabric, the method comprising: 1) activating a polyamide fiber fabric with a thickness of 0.3 mm and a density of 150 g / m2using oxygen plasma, under the environmental conditions of an oxygen atmosphere, a pressure of 40 Pa, a gas flow rate of 30 sccm, and a power of 100 W, using a radio frequency plasma generator for a treatment time of 7 min, to obtain a substrate. 2

[0038] 2) structurally optimizing the substrate surface using a chemical vapor deposition method, using hexamethyldisiloxane as the precursor, a nitrogen gas as the carrier gas, a flow rate of 50 sccm, under the environmental conditions of a temperature of 210 °C and a pressure of 30 Pa, for a deposition time of 45 min, to obtain an optimized substrate.

[0039] 3) annealing the optimized substrate at a low temperature, under the environmental conditions of a nitrogen atmosphere and a temperature of 100 °C, for a holding time of 45 min, to obtain a composite self-cleaning roller shutter fabric.

[0040] The roller shutter fabric prepared in this example was subjected to performance testing, and the specific characterization results are as follows.

[0041] Mechanical property testing: The fabric prepared in this example was subjected to mechanical property testing according to the ASTM D5034 testing method, using a universal material testing machine, and five test samples were taken along the warp and weft directions of the fabric, respectively, and the test samples were stretched to break at a rate of 50 mm / min, and the maximum load and elongation were recorded.

[0042] Abrasion resistance testing: The fabric prepared in this example was cut into five circular test samples with a diameter of 38 mm, a pressure of 12 kPa was applied, and wool felt was used as the friction medium, and the mass loss rate of the fabric after 5000 rubs was tested.

[0043] Chemical stability testing: The fabric prepared in this example was cut into ten test samples with a size of 100 mm x 100 mm, and was divided into two groups, which were immersed in acidic and alkaline reagents, respectively, for 24 h, then washed with deionized water for 3 times, dried, and then the tensile strength retention rate was tested. The acidic reagent was a 5% sulfuric acid solution, and the alkaline reagent was a 5% sodium hydroxide solution.

[0044] Hydrophobicity testing: The fabric prepared in this example was cut into test samples with a size of 20 mm x 20 mm, the test samples were fixed on the sample stage of a contact angle measuring instrument, 5 μL of deionized water was added dropwise, the droplet morphology was recorded by a high-speed camera, and the contact angle (θ) and roll-off angle (a) were calculated.

[0045] ​Self-cleaning efficiency detection: cut the fabric prepared in this example into a 20 mm x 20 mm detection sample, prepare carbon black dust with a particle size of 10 μm, place the detection sample on a 5° fixed angle inclined platform, set a water dripping device with a flow rate of 0.5 mL / s at the upper end 10 cm, sprinkle the dust at 0.1 g / m 2 2 on the surface of the detection sample and stand for 5 min, drip water at a constant flow rate, and record the time when the dust is completely washed away.

[0046] Interface bonding strength detection: use scratch test (ASTM D7027), apply a load of 0-50 N with a 200 μm radius diamond indenter, and record the critical force for peeling off the hydrophobic layer.

[0047]

[0048] Based on the above characterization results, the composite self-cleaning roller shutter fabric prepared in this example exhibits excellent comprehensive performance.

[0049] Example 3: A preparation method of a composite self-cleaning roller shutter fabric, the method comprising: 1) activating a polyamide fiber fabric with a thickness of 0.5 mm and a density of 150 g / m 2 2 in an oxygen plasma, using a radio frequency plasma generator under the following environmental conditions: oxygen atmosphere, pressure of 50 Pa, gas flow of 40 sccm, power of 120 W, and processing time of 3 min, to obtain a substrate.

[0050] 2) Structure optimization on the surface of the substrate is performed by chemical vapor deposition method, the precursor is hexamethyldisiloxane, the flow rate is 15 sccm, the carrier gas is nitrogen, the flow rate is 60 sccm, the deposition is performed under the following environmental conditions: temperature of 220 ℃, pressure of 50 Pa, and time of 30 min, to obtain an optimized substrate.

[0051] 3) The optimized substrate is subjected to low-temperature annealing under the following environmental conditions: nitrogen atmosphere and temperature of 120 ℃, and heat preservation for 30 min, to obtain a composite self-cleaning roller shutter fabric.

[0052] The roller shutter fabric prepared in this example is subjected to performance detection, and the specific characterization results are as follows.

[0053] Mechanical property detection: the fabric prepared in this example is detected according to the detection method of ASTM D5034, a universal material testing machine is used, 5 detection samples are taken along the warp and weft directions of the fabric, the detection sample is stretched to break at a rate of 50 mm / min, and the maximum load and elongation are recorded.

[0054] Abrasion resistance test: the fabric prepared in this example was cut into 5 circular test samples with a diameter of 38 mm, a pressure of 12 kPa was applied, wool felt was used as the friction medium, and the mass loss rate of the fabric after 5000 rubs was tested.

[0055] Chemical stability test: the fabric prepared in this example was cut into 10 test samples with a size of 100 mm x 100 mm, divided into two groups, and soaked in acidic and alkaline reagents for 24 h, respectively. After taking out, rinse with deionized water for 3 times, dry and test the tensile strength retention rate. The acidic reagent is 5% sulfuric acid solution, and the alkaline reagent is 5% sodium hydroxide solution.

[0056] Hydrophobicity test: the fabric prepared in this example was cut into test samples with a size of 20 mm x 20 mm, the test samples were fixed on the contact angle measuring instrument stage, 5 μL of deionized water was added dropwise, the droplet morphology was recorded by a high-speed camera, and the contact angle (θ) and rolling angle (α) were calculated.

[0057] Self-cleaning efficiency test: the fabric prepared in this example was cut into test samples with a size of 20 mm x 20 mm, carbon black dust with a particle size of 10 μm was prepared, the test samples were placed on a 5° fixed angle inclined platform, a water dripping device with a flow rate of 0.5 mL / s was set at the upper end 10 cm, the dust was evenly spread on the surface of the test sample at a rate of 0.1 g / m 2 2, and the water was dripped at a constant flow rate, and the time when the dust was completely washed away was recorded.

[0058] Interface bonding strength test: using scratch test (ASTM D7027), a diamond indenter with a radius of 200 μm was used to apply a load of 0~50 N, and the critical force of hydrophobic layer peeling was recorded.

[0059]

[0060] Based on the above characterization results, the composite self-cleaning roller shutter fabric prepared in this example exhibits excellent comprehensive performance.

[0061] Example 4: A preparation method of a composite self-cleaning roller shutter fabric, the method comprising: 1) activating a polyester fiber fabric with a thickness of 0.3 mm and a density of 150 g / m 2 2 by oxygen plasma, under the environmental conditions of oxygen atmosphere, pressure of 40 Pa, gas flow of 30 sccm, power of 100 W, using a radio frequency plasma generator for 7 min to prepare the substrate.

[0062] 2) The substrate surface was optimized by chemical vapor deposition, the precursor was hexamethyldisiloxane, the flow rate was 10 sccm, the carrier gas was nitrogen, the flow rate was 50 sccm, the deposition was carried out at a temperature of 210°C and a pressure of 30 Pa for 45 min, and the optimized substrate was prepared.

[0063] 3) The optimized substrate was annealed at a low temperature, and the composite self-cleaning roller blind fabric was prepared under the conditions of nitrogen atmosphere and a temperature of 100°C for 45 min.

[0064] The roller blind fabric prepared in this example was subjected to performance detection, and the specific characterization results are as follows.

[0065] Mechanical property detection: The fabric prepared in this example was detected according to the ASTM D5034 detection method, a universal material testing machine was used, 5 detection samples were taken along the warp and weft directions of the fabric, the sample was stretched to break at a rate of 50 mm / min, and the maximum load and elongation were recorded.

[0066] Abrasion resistance detection: The fabric prepared in this example was cut into 5 circular detection samples with a diameter of 38 mm, a pressure of 12 kPa was applied, wool felt was used as the friction medium, and the mass loss rate of the fabric after 5000 times of friction was tested.

[0067] Chemical stability detection: The fabric prepared in this example was cut into 10 detection samples with a size of 100 mm×100 mm, and was divided into two groups, which were soaked in acid reagent and alkaline reagent respectively for 24 h, then washed with deionized water for 3 times, dried and tested for tensile strength retention rate. The acid reagent was 5% sulfuric acid solution, and the alkaline reagent was 5% sodium hydroxide solution.

[0068] Hydrophobicity detection: The fabric prepared in this example was cut into detection samples with a size of 20 mm×20 mm, the detection sample was fixed on the contact angle measuring instrument stage, 5 μL of deionized water was added dropwise, the droplet shape was recorded by a high-speed camera, and the contact angle (θ) and rolling angle (α) were calculated.

[0069] Self-cleaning efficiency detection: The fabric prepared in this example was cut into detection samples with a size of 20 mm×20 mm, carbon black dust with a particle size of 10 μm was prepared, the detection sample was placed on a 5° fixed angle inclined platform, a water dripping device with a flow rate of 0.5 mL / s was set at the upper end 10 cm away, the dust was evenly spread on the surface of the detection sample at a rate of 0.1 g / m 2 2, and water was dripped at a constant flow rate, and the time when the dust was completely washed away was recorded.

[0070] Interface bonding strength detection: Scratch test (ASTM D7027) was used, a diamond indenter with a radius of 200 μm was used to apply a load of 0~50 N, and the critical force of hydrophobic layer peeling was recorded.

[0071]

[0072] Based on the above characterization results, the composite self-cleaning roller blind fabric prepared in this embodiment exhibits excellent comprehensive performance.

[0073] Comparative Example 1: Based on Example 2, only the treatment process of the raw material is changed in this example, and the remaining steps are the same as Example 2. The specific settings are as follows.

[0074]

[0075] The performance test method of the product of the comparative example is completely consistent with Example 1, and partial performance characterization is performed, and the characterization results are shown in the following table.

[0076]

[0077] Based on the above characterization results, in-depth analysis of the key process of oxygen plasma activation shows that its mechanism is to successfully introduce active functional groups such as hydroxyl (-OH) and carboxyl (-COOH) to the substrate surface through specific physical and chemical reactions. From the perspective of chemical structure and interaction, these active functional groups can have strong chemical bonding with the deposited layer formed in the subsequent chemical vapor deposition process. This chemical bonding is not simple physical adsorption, but is based on the redistribution and sharing of electron clouds between atoms, forming stable and firm chemical connections, thereby significantly enhancing the bonding strength between the substrate and the deposited layer.

[0078] If the key step of oxygen plasma activation is omitted during preparation, a series of adverse consequences will be caused. From the perspective of interfacial mechanical properties, due to the lack of chemical bonding mediated by the above-mentioned active functional groups, the interfacial bonding force between the substrate and the deposited layer will decrease significantly. This decrease in bonding force makes the originally tightly bonded two-layer structure loose, especially the hydrophobic layer, which is easily peeled off from the substrate surface when subjected to external small forces. The peeling of the hydrophobic layer not only destroys the integrity of the fabric surface, but also directly affects the self-cleaning performance of the fabric, resulting in a significant decrease in its self-cleaning performance. This is because the realization of self-cleaning function is highly dependent on the stable and uniform hydrophobic structure on the fabric surface. Once the hydrophobic layer is damaged or peeled off, the surface tension and capillary action, which are the key driving forces in the self-cleaning process, will be severely disturbed, and the dirt will not form droplets that are easy to roll under the action of surface tension, thus failing to achieve efficient self-cleaning effect.

[0079] By comparing the characterization results of Example 2 and D1-1, it can be clearly and deeply realized that the oxygen plasma activation treatment is of great significance to the performance of the fabric. In Example 2, a complete and carefully designed preparation process is strictly followed, which includes oxygen plasma activation, chemical vapor deposition, and low-temperature annealing, and other indispensable links. In this systematic preparation process, each link cooperates and synergizes with each other, so that the fabric exhibits excellent performance in multiple key performance indicators.

[0080] Specifically, in terms of wear resistance, the fabric can withstand a certain degree of friction and wear while maintaining the relative stability of structure and performance; in terms of hydrophobicity, the fabric has good hydrophobic performance, which can be directly reflected by the accurate measurement data of the two key parameters of contact angle and rolling angle. A larger contact angle indicates that the water droplets tend to form a nearly spherical shape on the fabric surface, minimizing the contact area with the fabric surface; a smaller rolling angle means that the water droplets can easily roll and slide on the fabric surface under the action of a small external force. This excellent hydrophobic performance plays a crucial role in the realization of the self-cleaning function, which ensures that stains can be effectively removed along with the rolling and sliding of water droplets, thereby maintaining the cleanliness of the fabric surface. In addition, in terms of interfacial bonding strength, the fabric exhibits a higher value, which is due to the formation of firm chemical bonds between the active functional groups introduced by oxygen plasma activation and the CVD layer, making the substrate and the hydrophobic layer closely connected, ensuring the stability and durability of the overall structure of the fabric.

[0081] However, in the D1-1 group, due to the cancellation of oxygen plasma activation treatment, only a relatively simple pretreatment method of ethanol ultrasonic cleaning of the polyamide fiber fabric, leading to the decline of multiple performance of the fabric in varying degrees. Among them, the decline of hydrophobicity is particularly significant, which is manifested in the decrease of contact angle and the increase of rolling angle. The decrease of contact angle means that the wettability of water droplets on the fabric surface is enhanced, and the water droplets can no longer exist stably in the form of a sphere, but are more likely to spread on the fabric surface; the increase of rolling angle indicates that the external force required for the rolling of water droplets on the fabric surface increases, making it difficult to roll and slide naturally. This deterioration of hydrophobicity directly affects the self-cleaning efficiency, making the stains more firmly attached to the fabric surface, which is difficult to remove by conventional water flow flushing or natural rolling.

[0082] At the same time, the decrease of interfacial bonding strength is also a prominent problem faced by the fabric in the D1-1 group. Due to the lack of chemical bonding effect provided by oxygen plasma activation, the bonding force between the hydrophobic layer and the substrate is significantly weakened. This weakening of the bonding force makes the hydrophobic layer prone to peeling off from the substrate surface during actual use, not only reducing the durability of the fabric and shortening its service life, but also damaging the stable surface structure on which the self-cleaning function depends, further affecting the durability and stability of the self-cleaning function.

[0083] Comparative Example 2: Based on Example 2, only the chemical vapor deposition process temperature is changed in this example, and the remaining steps are the same as Example 2. The specific settings are as follows.

[0084]

[0085] The performance test method of the product of the comparative example is completely consistent with Example 1, and partial performance characterization is performed, and the characterization results are shown in the following table.

[0086]

[0087] Analyzing the above characterization results, it is found that the low temperature environment has a significant impact on the cracking process of hexamethyldisiloxane. From the perspective of chemical reaction kinetics, under low temperature conditions, molecular thermal motion is slowed down, and the activation energy provided for the cracking reaction of hexamethyldisiloxane is relatively insufficient, resulting in insufficient cracking of hexamethyldisiloxane.

[0088] Under ideal conditions, hexamethyldisiloxane should form a complete and orderly three-dimensional Si-O-Si crosslinking network structure after sufficient cracking. This crosslinking network is crucial for maintaining the stability and functionality of the material, as it not only imparts good mechanical properties to the material, but also has a profound impact on the chemical properties of the material. However, due to insufficient cracking caused by low temperature, the three-dimensional Si-O-Si crosslinking network cannot be completely constructed, resulting in obvious defects in the pipe structure.

[0089] This structural defect directly leads to the deterioration of material performance. Specifically, both chemical corrosion resistance and hydrophobic stability show a downward trend. The decrease in chemical corrosion resistance means that the internal structure of the material is more easily damaged when it is exposed to chemical substances, because a complete crosslinking network can effectively block the penetration and reaction of chemical substances. The decline in hydrophobic stability indicates that the material's original hydrophobic properties are difficult to maintain stable over time or in certain environments, which may be related to changes in surface chemical properties caused by crosslinking network defects.

[0090] By systematically comparing the characterization results of Example 2 and D2-1, it can be clearly revealed that the chemical vapor deposition process temperature has a key impact on the performance of the fabric. In Example 2, a complete and precise preparation process is involved, including oxygen plasma activation, chemical vapor deposition, and low-temperature annealing. In this process, each step cooperates with each other, so that the fabric exhibits excellent performance in multiple performance dimensions.

[0091] The fabric showed good chemical corrosion resistance in the chemical stability test under acidic and basic conditions. This result fully proves that the preparation process can effectively build a stable microstructure, enabling the fabric to have strong resistance in complex chemical environments. Looking at the D2-1 group, when the chemical vapor deposition temperature is adjusted to 150 ℃, the situation changes significantly. Low-temperature environment causes hexamethyldisiloxane to be insufficiently cracked, and thus unable to form an intact three-dimensional Si-O-Si crosslinking network. This structural defect, like a domino effect, negatively affects various properties of the fabric. In terms of chemical corrosion resistance, due to the incompleteness of the crosslinking network, the fabric is more likely to react with chemicals under acidic and basic conditions, resulting in a significant decrease in chemical stability. From the chemical stability test results, it can be directly seen that the fabric performance of the D2-1 group is significantly inferior to that of Example 2. In addition, the decrease in self-cleaning efficiency also highlights the limitations of the fabric prepared under low-temperature chemical vapor deposition conditions. The self-cleaning function depends on the microstructure and chemical properties of the fabric surface, and the structural defects caused by low temperature change these key factors, so that the fabric cannot effectively utilize surface tension, capillary action, and other principles to remove stains during the self-cleaning process, resulting in insufficient self-cleaning efficiency.

[0092] Comparative Example 3: Based on Example 2, this example only modifies the chemical vapor deposition process, and the remaining steps are the same as Example 2. The specific settings are as follows.

[0093]

[0094] The performance test methods of the comparative product are exactly the same as those of Example 1, and the characterization results are shown in the following table.

[0095]

[0096] Analyzing the above characterization results, in terms of the siloxane fragments generated by methyltrichlorosilane, there are significant deficiencies in the construction of directional nanochannels. From the microstructure level, the effective formation of directional nanochannels requires specific molecular arrangement and interaction mechanisms, and the siloxane fragments generated by methyltrichlorosilane fail to meet this requirement, resulting in the inability to form ideal directional nanochannel structures.

[0097] This structural defect further triggers a series of performance problems. First, due to the absence or imperfection of the oriented nanochannel, the surface energy gradient of the fabric surface is difficult to achieve the ideal state, and the insufficient surface energy gradient directly weakens the capillary guiding effect. Capillary guiding effect plays a key role in the process of liquid transmission and particulate matter migration, and its weakening will inevitably have an adverse effect on the functionality of the entire system. Second, the low crosslinking density is also a problem that cannot be ignored. Crosslinking density reflects the tightness of intermolecular connection in the material, and lower crosslinking density means that the material has poor structural stability. When subjected to external friction and other forces, the material is more likely to wear, thereby leading to deterioration of wear resistance. At the same time, low crosslinking density will also affect the microtopography and chemical properties of the material surface, making it difficult to effectively overcome the interaction between stains and the material surface during the self-cleaning process, thereby leading to a decrease in self-cleaning efficiency.

[0098] By carefully comparing the characterization results of Example 2 and D3-1, it can be clearly seen that the selection of the precursor in the chemical vapor deposition process has a profound impact on the performance of the fabric. In Example 2, hexamethyldisiloxane was chosen as the precursor, and the preparation process was complete and accurately controlled. In this process, hexamethyldisiloxane, with its unique molecular structure and reactivity, participates in the construction of the microstructure of the fabric, making the fabric exhibit excellent performance in wear resistance, hydrophobicity, and self-cleaning efficiency, among other aspects.

[0099] It is particularly worth noting that in terms of hydrophobic performance, the data of contact angle and roll angle, two key parameters, can directly indicate that the fabric has excellent hydrophobic properties. A larger contact angle indicates that the liquid tends to form a spherical shape on the fabric surface and is not easy to spread; a smaller roll angle means that the liquid droplet can easily roll on the fabric surface. These two characteristics together ensure the good hydrophobic performance of the fabric, which is undoubtedly crucial for the effective realization of the self-cleaning function.

[0100] In contrast, in the D3-1 group, after the precursor is changed to methyltrichlorosilane, the structure of the generated siloxane fragment is abnormal. Essentially, the molecular structure and reactivity of methyltrichlorosilane differ from those of hexamethyldisiloxane, and this difference causes the generated siloxane fragment to fail to form an effective oriented nanochannel as expected.

[0101] This structural defect brings about multiple negative effects. On one hand, the energy gradient on the surface of the fabric cannot reach a reasonable level due to the absence of directional nanochannels, and the insufficient energy gradient directly weakens the capillary guiding effect, hindering the transmission and distribution of liquid on the surface of the fabric. On the other hand, the reduction of crosslinking density seriously affects the physical and chemical stability of the fabric. The reduction of crosslinking density means that the intermolecular interaction force is weakened, and the overall structure of the material becomes loose, which not only reduces the ability of the fabric to resist wear and tear, but also changes the chemical properties of the surface of the fabric, making it easier for stains to adhere, and in the self-cleaning process, stains are difficult to be quickly and effectively removed.

Claims

1. A method for preparing a composite self-cleaning roller blind fabric, characterized in that: The method comprises: 1) pre-treating raw materials to obtain a substrate; 2) optimizing the structure on the surface of the substrate by using a chemical vapor deposition method to obtain an optimized substrate; and 3) annealing the optimized substrate at a low temperature to obtain a composite self-cleaning roller blind fabric.

2. The method for preparing a composite self-cleaning roller blind fabric according to claim 1, characterized in that: Step 1) The raw material is polyester and / or polyamide fiber fabric with a thickness of 0.2-0.5 mm and a density of ≥150 g / m 2 .

3. The method for preparing a composite self-cleaning roller blind fabric according to claim 1 or 2, characterized in that: Step 1) The pretreatment is oxygen plasma activation, using a radio frequency plasma generator under the environmental conditions of oxygen atmosphere, pressure of 30-50 Pa, gas flow of 20-40 sccm, and power of 80-120 W for a treatment time of 3-10 min.

4. The method for preparing a composite self-cleaning roller blind fabric according to claim 1, characterized in that: Step 2) In the chemical vapor deposition method, the precursor is hexamethyldisiloxane with a flow rate of 5 to 15 sccm, the carrier gas is nitrogen with a flow rate of 40 to 60 sccm, and the deposition is carried out for 30 to 60 minutes under environmental conditions of a temperature of 200 to 220°C and a pressure of 10 to 50 Pa.

5. The method for preparing a composite self-cleaning roller blind fabric according to claim 1, characterized in that: Step 3) The low-temperature annealing is carried out in a nitrogen atmosphere at a temperature of 80-120° C. for 30-60 minutes.

6. A composite self-cleaning roller blind fabric produced by the method according to any one of claims 1 to 5.

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