Coating, preparation method therefor, and product comprising same
The preparation of polysiloxane monomer coatings by PECVD method solves the problems of complex preparation and poor liquid transfer of existing superhydrophobic surfaces, and realizes simple and efficient preparation of nanoscale coatings. It is suitable for the surface of electronic components and has excellent superhydrophobicity and stable liquid transfer.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- JIANGSU FAVORED NANOTECHNOLOGY CO LTD
- Filing Date
- 2025-07-01
- Publication Date
- 2026-06-11
AI Technical Summary
The existing superhydrophobic surface preparation process is complex and not easy to industrialize, and the commonly used fluorine-free superhydrophobic coating oil has a large contact angle hysteresis, making it difficult to remove droplets from the surface.
A polysiloxane monomer coating was prepared by PECVD. The nanoscale coating was formed on the substrate surface by plasma discharge. The water roll-off angle of the coating was below 30 degrees, and the polysiloxane chains could rotate and move freely, exhibiting excellent superhydrophobicity and stable liquid transfer properties.
It enables the simple preparation of nanoscale coatings with excellent superhydrophobicity and stable liquid transfer properties, suitable for industrial production and for the surfaces of electronic components with high precision requirements, while reducing coating thickness and preparation complexity.
Smart Images
Figure CN2025106407_11062026_PF_FP_ABST
Abstract
Description
Coatings, their preparation methods, and products including them
[0001] This application claims priority to Chinese Patent Application No. CN202411793374.3, filed on December 6, 2024, entitled "Coating, Method of Preparation Thereof and Products Including Thereof", the entire contents of which are incorporated herein by reference. Technical Field
[0002] This invention relates to the field of surface treatment, and more particularly to a coating, a method for preparing the same, and products comprising the same. Background Technology
[0003] Superhydrophobic surfaces are widely used in self-cleaning, anti-icing, and anti-corrosion applications due to their ability to repel aqueous solutions and some organic liquids. Minimizing contact hysteresis is key to facilitating droplet removal from the surface. When the contact hysteresis is relatively small, droplets only require a small surface tilt angle to move smoothly downwards, avoiding pinning and significant droplet deformation. Although superhydrophobic surfaces have low water contact hysteresis, they generally require the formation of special morphologies through laser etching, making the fabrication process complex and difficult for industrial production. Furthermore, the surface morphology is easily damaged, increasing the water contact hysteresis and making water removal difficult. Meanwhile, commonly used fluorine-free superhydrophobic coatings exhibit large contact hysteresis and lack oil-repellent properties.
[0004] Therefore, a relatively stable surface with liquid-fluidizing properties can be formed by utilizing the co-hydrolysis and co-condensation between siloxanes through the sol-gel method. The free rotation and movement of the siloxane chains impart liquid-like properties to the surface, making it easy to remove liquids. However, coatings prepared by the sol-gel method are typically tens of micrometers thick, making them impractical for high-precision electronic component surfaces. Furthermore, the precursors for the sol-gel method generally include multiple siloxanes and catalysts, making the preparation method complex. Summary of the Invention
[0005] This invention provides a nanoscale coating with excellent superhydrophobicity and stable liquid transfer properties that can be easily prepared, a method for preparing the same, and products including the same.
[0006] One aspect of this invention relates to a coating formed from a polysiloxane monomer by a PECVD method, wherein the coating has a water roll-off angle of less than 30 degrees.
[0007] The polysiloxane monomer has the following structural formula (I) and a number-average molecular weight of 200 to 1500:
[0008] Where n is an integer from 1 to 1000.
[0009] In some embodiments, the water roll-off angle of the coating is below 20 degrees.
[0010] In some embodiments, the water roll-off angle of the coating is less than 15 degrees.
[0011] In some embodiments, the oil roll-off angle of the coating is less than 10 degrees.
[0012] In some embodiments, the water contact angle of the coating is above 90 degrees.
[0013] In some embodiments, the number-average molecular weight of the polysiloxane monomer is 500 to 1200.
[0014] Another aspect of this invention relates to a method for preparing a coating, which includes the following steps:
[0015] Provide a substrate, place the substrate in a plasma reactor; and
[0016] Gaseous polysiloxane monomers are introduced into a plasma reactor to perform plasma discharge, thereby forming a coating on the substrate surface through plasma polymerization.
[0017] Plasma discharge includes continuous discharge and / or pulsed discharge. The discharge power of continuous discharge is 10W to 300W and the discharge time is 60 seconds to 36,000 seconds. The discharge power of pulsed discharge is 10W to 400W and the discharge time is 200 seconds to 36,000 seconds.
[0018] In some embodiments, the reaction temperature for plasma polymerization is between 30°C and 60°C.
[0019] In some embodiments, the average discharge power of the pulsed discharge is 60W to 75W.
[0020] Another aspect of the present invention relates to a product whose surface at least partially includes the coating of this application.
[0021] Another aspect of the present invention relates to a product whose surface at least partially comprises a coating obtained by the method of the present application.
[0022] The technical solutions of this application embodiment can facilitate the simple preparation of nanoscale coatings with excellent superhydrophobicity and stable liquid transfer properties. Attached Figure Description
[0023] Figure 1 shows the relationship between the average discharge power of the pulsed discharge and the water roll-off angle of the coating in Examples 1, 3, 5, 6 and Comparative Example 4; and
[0024] Figure 2 shows the relationship between the number-average molecular weight of the polysiloxane monomers and the water roll-off angle of the coatings in Examples 1, 2, 4, 5, 7 and Comparative Examples 1, 2 and 3. Detailed Implementation
[0025] One aspect of this invention relates to a coating formed from a polysiloxane monomer by a PECVD method, wherein the coating has a water roll-off angle of less than 30 degrees.
[0026] Polysiloxane monomers have the following structural formula (I) (i.e., hydrogen-terminated polydimethylsiloxane) and a number-average molecular weight of 200 to 1500:
[0027] Where n is an integer from 1 to 1000.
[0028] Polysiloxane chains are relatively flexible and can move freely. In this embodiment of the invention, the polysiloxane oligomer is used as a reactive monomer and further polymerized into a polysiloxane coating by PECVD. Because the siloxane chains in the polysiloxane coating can rotate and move freely, the polysiloxane coating has liquid-like properties, and therefore exhibits stable liquid transfer properties and excellent superhydrophobic properties.
[0029] The coating in this embodiment of the invention is formed by PECVD, and the coating thickness can reach the nanometer level.
[0030] In addition, the coating of this invention uses only one polysiloxane oligomer as the reaction raw material for the PECVD process, without the need to add other monomers or other raw materials. The coating preparation process is simple, highly repeatable, and suitable for industrial production.
[0031] Furthermore, the coating of this embodiment has a water roll-off angle of less than 30 degrees, exhibiting excellent water repellency.
[0032] In this embodiment of the invention, "liquid repellency" refers to the property of removing liquids from a surface, such as the property of removing water or oil from a coating surface, i.e., water repellency and oil repellency.
[0033] In this embodiment of the invention, unless otherwise specifically indicated, the numerical range may include any sub-range therein. For example, a number-average molecular weight of 200 to 1500 may include 250 to 1300, 450 to 1000, 500 to 900, 550 to 800, 600 to 700, and below 30 degrees may include 30 degrees, 25 degrees, 20 degrees, 15 degrees, 10 degrees, 5 degrees, etc.
[0034] In this embodiment of the invention, the roll-off angle of the coating refers to the critical angle formed by the inclined surface and the horizontal plane when the droplet just begins to roll on the inclined surface. Specifically, when the droplet is a water droplet, the roll-off angle is the water roll-off angle; when the droplet is an oil droplet, the roll-off angle is the oil roll-off angle.
[0035] In this embodiment of the invention, the water contact angle of the coating refers to the angle between the tangent of the gas-liquid interface at the junction of the gas, liquid, and solid phases and the liquid-solid interface.
[0036] In some embodiments, the water roll-off angle of the coating is below 20 degrees.
[0037] In some embodiments, the water roll-off angle of the coating is less than 15 degrees.
[0038] In some embodiments, the oil roll-off angle of the coating is less than 10 degrees.
[0039] The coating has an oil roll-off angle of less than 10 degrees, thus exhibiting excellent oil repellency.
[0040] In some embodiments, the water contact angle of the coating is above 90 degrees.
[0041] In this way, the coating can have excellent hydrophobicity.
[0042] In some embodiments, the number-average molecular weight of the polysiloxane monomer is 500 to 1200.
[0043] For example, the number average molecular weight of polysiloxane monomers can be between 580 and 1000.
[0044] Another aspect of this invention relates to a method for preparing a coating, which includes the following steps:
[0045] Provide a substrate, place the substrate in a plasma reactor; and
[0046] Gaseous polysiloxane monomers are introduced into a plasma reactor to perform plasma discharge, thereby forming a coating on the substrate surface through plasma polymerization.
[0047] Plasma discharge includes continuous discharge and / or pulsed discharge. The discharge power of continuous discharge is 10W to 300W and the discharge time is 60 seconds to 36,000 seconds. The discharge power of pulsed discharge is 10W to 400W and the discharge time is 200 seconds to 36,000 seconds.
[0048] In this embodiment of the invention, a PECVD method is performed by continuously discharging polysiloxane monomers with a logarithmic molecular weight of 200 to 1500 for 60 to 36000 seconds at a discharge power of 10 W to 300 W, or by pulse discharging for 200 to 36000 seconds at a discharge power of 10 W to 400 W. This process can form a nanoscale coating with excellent superhydrophobicity and stable liquid transfer properties with a water roll-off angle of less than 30 degrees.
[0049] In some embodiments, before the polysiloxane monomer is introduced into the plasma reactor, the substrate in the plasma reactor can be pretreated by solvent cleaning, plasma bombardment, or other methods to enhance the adhesion between the subsequently formed coating and the substrate surface. "Plasma bombardment" can be performed by continuous discharge of 50W to 600W for 60 seconds to 2400 seconds or pulsed discharge of 10W to 500W for 60 seconds to 2400 seconds.
[0050] In the above embodiments of the present invention, the pulse duty cycle in the pulse discharge is 0.1% to 90%, and the pulse frequency is 10Hz to 500Hz.
[0051] Gaseous polysiloxanes can be obtained by vaporizing polysiloxane monomers at temperatures ranging from 60°C to 150°C.
[0052] The plasma process gas source in "plasma discharge" may include at least one of an inert gas and oxygen. The inert gas may include helium and / or argon. The plasma reactor may be evacuated before introducing the plasma source gas. Introducing the plasma source gas into the plasma reactor may be performed before introducing the gaseous form of the polysiloxane monomer into the plasma reactor.
[0053] In the embodiments of the present invention, unless otherwise specifically indicated, the "plasma discharge" method may include electrodeless discharge (such as radio frequency inductively coupled discharge, microwave discharge), single-electrode discharge (such as corona discharge, plasma jet formed by unipolar discharge), two-electrode discharge (such as dielectric barrier discharge, radio frequency glow discharge of bare electrodes), and multi-electrode discharge (such as discharge using a floating electrode as a third electrode).
[0054] In some embodiments, the reaction temperature for plasma polymerization is between 30°C and 60°C.
[0055] In some embodiments, the average discharge power of the pulsed discharge is 60W to 75W.
[0056] This allows for the preparation of coatings with lower roll-off angles, such as 9 to 13 degrees.
[0057] In this embodiment of the invention, the average discharge power of the pulse discharge is defined as: P = Pcw × D, where P is the average discharge power, D is the duty cycle, and Pcw is the pulse discharge power.
[0058] Another aspect of the present invention relates to a product whose surface at least partially includes the coating of this application.
[0059] Another aspect of the present invention relates to a product whose surface at least partially comprises a coating obtained by the method of the present application.
[0060] The products can include various devices with high precision requirements for coating thickness. For example, the devices can be electronic or electrical components, optical instruments, etc. Specifically, electrical components can be printed circuit boards (PCBs), electronic products, or semi-finished electronic assemblies. When the device is an electronic product, examples include, but are not limited to, mobile phones, tablets, keyboards, e-readers, wearable devices, displays, headphones, etc. The device can also be any suitable electrical component of an electrical assembly; specifically, the electrical component can be a resistor, capacitor, transistor, diode, amplifier, relay, transformer, battery, fuse, integrated circuit, switch, mobile phone screen, LED, LED display, piezoelectric element, optoelectronic component, antenna, or oscillator, etc.
[0061] The technical solutions of the embodiments of the present invention can help provide products with nanoscale coatings that are easy to prepare and have excellent superhydrophobicity and stable liquid transfer properties as the coating surface. This can help improve the hydrophobicity and liquid transfer properties of the product surface, reduce the thickness of the coating on the product surface and its preparation complexity, etc.
[0062] The embodiments of the present invention will be illustrated below with specific examples. These examples are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.
[0063] Example 1
[0064] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0065] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0066] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number-average molecular weight of 580 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 30%, the pulse frequency was 50 Hz, the pulse discharge power was 200 W (average power 60 W), and the reaction time was 3000 seconds for coating.
[0067] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0068] Example 2
[0069] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0070] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0071] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number average molecular weight of 1000 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 30%, the pulse frequency was 50 Hz, the pulse discharge power was 200 W (average power 60 W), and the reaction time was 3000 seconds for coating.
[0072] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0073] Example 3
[0074] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0075] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0076] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number-average molecular weight of 580 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 30%, the pulse frequency was 50 Hz, the pulse discharge power was 250 W (average power 75 W), and the reaction time was 3000 seconds for coating.
[0077] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0078] Example 4
[0079] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0080] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0081] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number average molecular weight of 1000 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 50%, the pulse frequency was 50 Hz, the pulse discharge power was 300 W (average power 150 W), and the reaction time was 3000 seconds for coating.
[0082] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0083] Example 5
[0084] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0085] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0086] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number-average molecular weight of 580 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 50%, the pulse frequency was 50 Hz, the pulse discharge power was 300 W (average power 150 W), and the reaction time was 3000 seconds for coating.
[0087] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0088] Example 6
[0089] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0090] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0091] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number-average molecular weight of 580 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 50%, the pulse frequency was 50 Hz, the pulse discharge power was 400 W (average power 200 W), and the reaction time was 3000 seconds for coating.
[0092] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0093] Example 7
[0094] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0095] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0096] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number-average molecular weight of 208 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 30%, the pulse frequency was 50 Hz, the pulse discharge power was 200 W (average power 60 W), and the reaction time was 3000 seconds for coating.
[0097] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0098] Comparative Example 1
[0099] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0100] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0101] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number average molecular weight of 2000 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 30%, the pulse frequency was 50 Hz, the pulse discharge power was 200 W (average power 60 W), and the reaction time was 3000 seconds for coating.
[0102] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0103] Comparative Example 2
[0104] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0105] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0106] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number average molecular weight of 2000 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 50%, the pulse frequency was 50 Hz, the pulse discharge power was 300 W (average power 150 W), and the reaction time was 3000 seconds for coating.
[0107] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0108] Comparative Example 3
[0109] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0110] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0111] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number-average molecular weight of 208 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 50%, the pulse frequency was 50 Hz, the pulse discharge power was 300 W (average power 150 W), and the reaction time was 3000 seconds for coating.
[0112] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0113] Comparative Example 4
[0114] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0115] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0116] After pretreatment, hydrogen-terminated polydimethylsiloxane monomer with a number-average molecular weight of 580 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 20%, the pulse frequency was 50 Hz, the pulse discharge power was 100 W (average power 20 W), and the reaction time was 3000 seconds for coating.
[0117] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0118] Comparative Example 5
[0119] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0120] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0121] After pretreatment, methyl-terminated polydimethylsiloxane monomer with a number average molecular weight of 1500 was introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure was maintained at 120 mTorr and the helium flow rate was maintained at 80 sccm. Plasma pulse discharge was activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle was 30%, the pulse frequency was 50 Hz, the pulse discharge power was 200 W (average power 60 W), and the reaction time was 3000 seconds for coating.
[0122] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0123] Comparative Example 6
[0124] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0125] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0126] After pretreatment, a polysiloxane monomer with the following structural formula (II) and a number-average molecular weight of 2000 is introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure is maintained at 120 mTorr and the helium flow rate is maintained at 80 sccm. Plasma pulse discharge is activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle is 30%, the pulse frequency is 50 Hz, the pulse discharge power is 200 W (average power 60 W), and the reaction time is 3000 seconds for coating.
[0127] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0128] Comparative Example 7
[0129] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0130] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0131] After pretreatment, a polysiloxane monomer with the following structural formula (III) and a number-average molecular weight of 2500 is introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure is maintained at 120 mTorr and the helium flow rate is maintained at 80 sccm. Plasma pulse discharge is activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle is 30%, the pulse frequency is 50 Hz, the pulse discharge power is 200 W (average power 60 W), and the reaction time is 3000 seconds for coating.
[0132] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0133] Comparative Example 8
[0134] The Si wafer and the mobile phone screen were placed on the substrate placement bracket inside the plasma reactor chamber. The chamber was then evacuated to 120 mTorr, helium gas was introduced at a flow rate of 80 sccm, and the chamber temperature was adjusted to 45°C.
[0135] Maintain the chamber pressure at 120 mTorr and the helium flow rate at 80 sccm, initiate continuous plasma discharge with a discharge power of 300 W, and discharge for 100 seconds to pretreat the substrate.
[0136] After pretreatment, a polysiloxane monomer with the following structural formula (IV) and a number-average molecular weight of 1500 is introduced into the evaporator at a flow rate of 240 μL / min and vaporized at 150 °C before being introduced into the plasma reactor chamber. The chamber pressure is maintained at 120 mTorr and the helium flow rate is maintained at 80 sccm. Plasma pulse discharge is activated to perform plasma chemical vapor deposition on the substrate surface. The pulse duty cycle is 30%, the pulse frequency is 50 Hz, the pulse discharge power is 200 W (average power 60 W), and the reaction time is 3000 seconds to perform the coating.
[0137] After coating, compressed air was introduced to restore the plasma reactor chamber to atmospheric pressure. The coated substrate was then removed, and the film thickness on the Si wafer was measured using a thin film thickness meter according to GB / T 40279-2021 standard. Furthermore, the water contact angle (droplet angle) and roll-off angle of the mobile phone screen were measured according to GB / T 30447-2013 and GB / T 42694-2023 standards, respectively. The roll-off angle was obtained by testing with 20 μL of water and 10 μL of n-hexadecane, respectively. The test results are listed in Table 1 below.
[0138] Table 1. Test results of the coatings in Examples 1-6 and Comparative Examples 1-9
[0139] Referring to Table 1, the number-average molecular weight of the hydrogen-terminated polydimethylsiloxane monomers in Examples 1, 3, 5, 6, and Comparative Example 4 was 580, and the average discharge power of the pulsed discharge was 60W, 75W, 150W, 200W, and 20W, respectively. Figure 1 shows the relationship between the average discharge power of the pulsed discharge and the water roll-off angle of the coating in Examples 1, 3, 5, 6, and Comparative Example 4. As shown in Figure 1, under the condition of the same number-average molecular weight of the polysiloxane monomers, the water roll-off angle of the coating first decreased and then increased with the increase of the average discharge power. When the average discharge power was between 60W and 75W, the coating exhibited good low water roll-off angle performance, with the water roll-off angle ranging from 9 degrees to 13 degrees. When the average discharge power is low, for example below 60W, a relatively complete nano-coating cannot be formed. The coating surface lacks long-chain siloxanes that can make droplets roll, resulting in an increased water roll-off angle of the coating. When the average power is high, for example above 75W, the high plasma intensity causes the long-chain siloxanes to be pinned to the coating surface, making it impossible to form a surface with freely moving long-chain siloxanes. This causes the coating surface to lose its "liquid-like" properties, ultimately leading to an increased water roll-off angle of the coating.
[0140] Figure 2 shows the relationship between the number-average molecular weight of the polysiloxane monomers and the water roll-off angle of the coatings in Examples 4 and 5 and Comparative Examples 2 and 3. The average discharge power in Examples 4 and 5 and Comparative Examples 2 and 3 was 150 W, and the molecular weights of the polysiloxane monomers were 1000, 580, 2000, and 208, respectively. As can be seen from Figure 2, under the same average power condition, the water roll-off angle of the coating first decreases and then increases with increasing molecular weight. The water roll-off angle is lowest, ranging from 21 to 28 degrees, when the number-average molecular weight of the polysiloxane monomers is between 580 and 1000. In Examples 1, 2, and 7 and Comparative Example 1, the average discharge power was 60 W, and the number-average molecular weights of the polysiloxane monomers were 580, 1000, 208, and 2000, respectively. With increasing molecular weight, the water roll-off angle of the coating also showed a trend of first decreasing and then increasing. The water roll-off angle of the coating was also lowest, ranging from 9 to 15 degrees, when the number-average molecular weight of the polysiloxane monomers was between 580 and 1000. Under two different power conditions, the water roll-off angle of the coating showed the same trend with the change in the number-average molecular weight of the polysiloxane monomers: it first decreased and then increased with the increase of the number-average molecular weight. When the number-average molecular weight of the polysiloxane monomers was too low, the siloxane chains were shorter, and the free mobility of shorter siloxane chains was much less than that of long-chain siloxanes, resulting in an increased water roll-off angle of the coating. When the number-average molecular weight of the polysiloxane monomers was too high, the viscosity was too high, and the monomers blocked at the feed inlet, unable to enter the coating chamber and form a polysiloxane coating on the substrate surface. Therefore, the water roll-off angle of the coating increased significantly, and the coating thickness was also very small due to the small amount of monomers fed. As can be seen from Comparative Examples 1 and 2, when the molecular weight was 2000, even if the average power was increased from 60W to 150W, the coating thickness did not increase significantly. This is because the monomer concentration in the chamber was too low, and the effect of the average discharge power was limited.
[0141] From the above, it can be concluded that the average discharge power of plasma discharge and the molecular weight of polysiloxane monomers have a significant impact on the roll-off angle of the coating. Only when the number-average molecular weight of the polysiloxane monomers is between 580 and 1000, and the average discharge power is between 60W and 75W, can coatings with good low roll-off performance be produced by PECVD deposition.
[0142] Furthermore, in Table 1, the average discharge power of Comparative Examples 5 to 8 was 60 W, the polysiloxane monomers were all methyl-terminated, and the number-average molecular weights were 1500, 2000, 2500, and 1500, respectively. The water roll-off angles of the coatings were all relatively large, exceeding 30 degrees. Although the number-average molecular weight of the polysiloxane monomers in Comparative Example 8 was the same as that in Comparative Example 5, the polysiloxane monomers in Comparative Example 8 had branched molecules. Therefore, even at the same average discharge power, the water roll-off angle of the final coating in Comparative Example 8 was significantly higher than that in Comparative Example 5. Additionally, although the number-average molecular weight of the polysiloxane monomers in Comparative Example 8 was smaller than that in Comparative Example 7, the water roll-off angle of the coating in Comparative Example 8 was much larger than that of the coating in Comparative Example 7 at the same average discharge power. This may be because the degree of molecular branching and the length of the branched chains in the polysiloxane monomers in Comparative Example 8 were higher than those in Comparative Example 7. This shows that coatings formed by PECVD of polysiloxane monomers with linear structures and hydrogen-capped ends can have relatively low water roll-off angles.
[0143] The various specific embodiments described above and shown in the accompanying drawings are for illustrative purposes only and do not represent the entirety of the invention. Any modifications made by those skilled in the art within the scope of the basic technical concept of this invention are within the protection scope of this invention.
Claims
1. A coating characterized in that, The coating is formed from polysiloxane monomers via PECVD, and the water roll-off angle of the coating is below 30 degrees. The polysiloxane monomer has the following structural formula (I) and a number-average molecular weight of 200 to 1500: Where n is an integer from 1 to 1000.
2. The coating of claim 1, wherein, The water roll-off angle of the coating is below 20 degrees.
3. The coating of claim 1, wherein, The water roll-off angle of the coating is below 15 degrees.
4. The coating of claim 1, wherein, The oil roll-off angle of the coating is below 10 degrees.
5. The coating of claim 1, wherein, The water contact angle of the coating is above 90 degrees.
6. The coating of claim 1, wherein, The number average molecular weight of the polysiloxane monomer is between 500 and 1200.
7. A method of preparing a coating according to any one of claims 1 to 6, characterized in that, Includes the following steps: A substrate is provided, and the substrate is placed in a plasma reactor; as well as The gaseous polysiloxane monomer is introduced into the plasma reactor to perform plasma discharge, thereby forming the coating by plasma polymerization on the substrate surface. The plasma discharge includes continuous discharge and / or pulsed discharge. The continuous discharge has a discharge power of 10W to 300W and a discharge time of 60 seconds to 36,000 seconds. The pulsed discharge has a discharge power of 10W to 400W and a discharge time of 200 seconds to 36,000 seconds.
8. The method of claim 7, wherein, The reaction temperature for plasma polymerization is between 30°C and 60°C.
9. The method of claim 7, wherein, The average discharge power of the pulsed discharge is 60W to 75W.
10. A product characterized by, At least a portion of the surface comprises the coating as described in any one of claims 1 to 6.
11. A product characterized by, At least a portion of the surface comprises a coating obtained by the method of any one of claims 7 to 9.