A porous surface having slippery lubricant-infused and preparation method thereof

Abstract

This invention relates to a porous surface with lubricant injection and a method for preparing the same. The method includes: first, providing a substrate; then, providing a composition of a plurality of surface particles; next, fixing the plurality of surface particles onto the substrate to form a porous particle surface; and finally, forming a lubricant surface on the porous particle surface. The porous surface with lubricant injection of this invention includes a substrate, a plurality of first polystyrene particles and a plurality of second silica particles formed on the surface of the substrate, and a lubricant impregnating the porous surface and forming between the plurality of first particles and the plurality of second particles.

Description

Technical Field

[0001] This invention relates to a porous surface and a method for preparing the same, particularly to a porous surface with lubricant injection capability and a method for preparing the same. Prior Technology

[0002] As is well known, many plants and animals in nature have very special functions. For example, geckos can walk on vertical walls, chameleons or cephalopods can change their skin color to hide from threats, spider silk can help spiders capture prey and can stay in place for a long time, and lotus leaves emerge from the mud unsullied, becoming the famous lotus leaf effect. These are the origins of the idea for biomimetic superhydrophobic surfaces, and people are increasingly applying their biomimetic concepts to their daily lives to help them pursue a more convenient life.

[0003] The self-cleaning ability of superhydrophobic surfaces stems from their combination of micro / nano-level roughness with low surface energy materials, making it difficult for water droplets to adhere to the surface and achieving the same effect as the lotus leaf effect, where the water contact angle needs to be greater than 150°. In 2011, a new type of self-cleaning surface was proposed, called "slippery lubricant-infused porous surface (SLIPS)." Unlike lotus leaves, the surface of the pitcher plant's lips, while possessing radially arranged groove-like microstructures, does not directly resist external liquids. Instead, liquid fills these pore textures, adhering completely to the pores to form a lubricating film, thereby repelling external fluids. The primary function of the pores is to lock in the liquid and also to provide surface roughness. Based on this concept, a lubricant is injected into a porous surface, filling the air layer of the superhydrophobic surface with the lubricant to form a lubricating layer. Because the fluid has the characteristic of filling a position with lower potential energy, it can flow freely on the surface, has self-healing properties, and its mechanical properties are also improved. It can also make it easier for various foreign fluids to slide off, thus overcoming the bottleneck of superhydrophobic surfaces.

[0004] The aforementioned method for injecting lubricant into porous surfaces utilizes fluorine-based materials because fluorine provides extremely low surface energy. Subsequently, other studies have proposed using fluorine-based materials to create lubricant injection surfaces. However, even with its extremely low surface energy, fluorine raises concerns about releasing toxic gases upon high-temperature heating, necessitating improvements. Eliminating the use of fluorine would also be a crucial step in implementing environmental protection principles. Summary of the Invention

[0005] The present invention relates to a porous surface with lubricant injection and a method for preparing the same, that is, a method for preparing a porous surface with lubricant injection, and or, a porous surface with lubricant injection.

[0006] One method for preparing a porous surface with lubricant injection according to the present invention includes: first, providing a substrate, then providing a surface particle composition, wherein the surface particle composition includes one or more surface particles dispersed in one or more dispersions, then fixing the surface particles onto the substrate to form a porous particle surface, and finally forming a lubricant surface on the porous particle surface.

[0007] The present invention provides a method for preparing a porous surface with lubricant injection. One of its advantages is that the substrate and surface particles are heat-treated at a temperature not lower than the glass transition point of the material, so that they can be fixed together.

[0008] The present invention discloses a method for preparing a porous surface with lubricant injection. One of its advantages is that the step of providing the surface particle composition includes preparing a first particle dispersion solution and a second particle dispersion solution that can be mixed with each other.

[0009] The present invention discloses a method for preparing a porous surface with lubricant injection, one advantage of which is that no adhesive is used, and therefore no fluorine is used.

[0010] The present invention provides a porous surface with lubricant injection, one advantage of which is that it does not use fluorine, which has extremely low surface energy but raises concerns about biotoxicity after heating.

[0011] The present invention provides a porous surface with lubricant injection, comprising a substrate, wherein a plurality of first polystyrene particles and a plurality of second silica particles are formed on the surface of the substrate, and a lubricant is impregnated between the plurality of first particles and the plurality of second particles to form a porous surface.

[0012] The present invention provides a porous surface with lubricant injection, one advantage of which is that the substrate is composed of various materials such as metal, plastic, polymer, and wood.

[0013] The present invention provides a porous surface with lubricant injection, one advantage of which is that the first particle comprises: silicon dioxide particles, polystyrene particles, and poly(3-hydroxybutyrate-co-4-hydroxybutyrate), P34HB particles, and the particle size is between 300 nanometers and 400 nanometers.

[0014] The present invention provides a porous surface with lubricant injection, one advantage of which is that the second particle comprises: silicon dioxide particles, polystyrene particles, and poly(3-hydroxybutyl ester-co-4-hydroxybutyl ester) particles, and the particle size is between 300 nanometers and 400 nanometers.

[0015] The present invention provides a porous surface with lubricant injection, one advantage of which is that the lubricant comprises linear polysilane material and polydimethylsiloxane.

[0016] The present invention provides a porous surface for lubricant injection, one advantage of which is that the prepared coating has anti-adhesion and self-cleaning properties for common fluids and extracorporeal circulation tubing infusion.

[0017] The present invention provides a porous surface with lubricant injection, one advantage of which is that it can reduce the rupture and damage of blood cells when used in medical surgery.

[0018] The present invention provides a porous surface with lubricant injection, one advantage of which is that it can remain unchanged under repeated silicone oil immersion and anti-sticking tests, and has excellent reusability.

[0019] The present invention provides a porous surface with lubricant injection, one advantage of which is that when the surface is scratched by external force, the silicone oil can spontaneously fill the area with lower potential energy, promoting the self-healing process.

[0020] The present invention provides a porous surface with lubricant injection, one of the advantages of which is that it can resist frost adhesion under drastic temperature changes and has excellent mechanical strength and resistance to cold and heat. Simple Explanation of the Diagram

[0021] Figure 1 is a schematic diagram of a method for preparing a porous surface with lubricant injection according to the present invention. Figure 2 is a cross-sectional schematic diagram of a porous surface with lubricant injection according to the present invention. Figure 3A is a schematic diagram of the "anti-icing test" of the present invention. Figure 3B is a schematic diagram of the control group for the "anti-icing test" of this invention. Figure 4 is a schematic diagram of the "anti-icing test" of the present invention. Implementation

[0022] The following specific embodiments illustrate the present invention, which is a porous surface with lubricant injection and its preparation method, namely the "Lactant-Wet Porous Surface (SLIPS)" and its preparation method of the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed herein. The present invention can be implemented or applied through other specific embodiments. Various details can be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. The accompanying drawings of the present invention are only simple illustrations and are not depicted according to actual dimensions. For ease of explanation, specific details may be enlarged. The term "or" used herein should be interpreted to include any or more combinations of the associated listed items as appropriate.

[0023] The substrate referred to in this invention includes, but is not limited to, various materials, including metallic materials, such as those listed in the periodic table, or plastic materials, or polymeric materials, including silicone gel, polydimethylsiloxane (PDMS), or polyvinyl chloride (PVC), as well as gauze (degreased cotton), and various materials such as wood.

[0024] The surface particles referred to below in this invention are low surface energy materials with hydrophobic properties. They may include a combination of particles of one or more materials and can be fixed to the surface of a substrate by appropriate methods. Examples include silicon dioxide (SiO2) particles, polystyrene (PS) particles, and poly(3-hydroxybutyrate-co-4-hydroxybutyrate), P34HB particles. The particle size should be between 300 and 400 nanometers, and they should have a narrow distribution. Suitable methods, such as, but not limited to, dispersion in a suitable dispersion solution followed by spin coating or dip coating, can be used.

[0025] The lubricant referred to in this invention is a combination of one or more highly biocompatible materials and a polymeric material that remains liquid at room temperature, such as linear polysilane or polydimethylsiloxane.

[0026] Figure 1 is a schematic diagram of a method for preparing a porous surface with lubricant injection according to the present invention. First, please refer to step 10 in Figure 1, which is the "step of providing a substrate", and the substrate can be pretreated to facilitate subsequent processes. In the first embodiment, a silicone board is used as the substrate, and it is cleaned, dried and light-treated to modify the surface of the silicone board.

[0027] Figure 1 illustrates a method for preparing a porous surface with lubricant injection according to the present invention. Referring again to step 10 in Figure 1, the silicone substrate surface is cleaned of dirt and organic matter by ultrasonic oscillation, washed with deionized water, dried, and then irradiated with an ultraviolet (UV) light-modifying lamp. During the light treatment process, photon energy breaks the molecular bonds on the surface of the object and releases hydrogen ions. Oxygen molecules in the air absorb the photon energy and generate oxygen ions. The hydrogen ions and oxygen ions combine to form hydrophilic groups such as hydroxyl (OH-) bonds on the silicone substrate surface, making the silicone substrate surface more hydrophilic, which facilitates the subsequent adhesion of surface particles.

[0028] Referring again to Figure 1, a schematic diagram of a method for preparing a porous surface with lubricant injection according to the present invention, and continuing to refer to step 12 of Figure 1, which is the "step of providing a surface particle composition", nano-sized particles of one or more materials are dispersed in a dispersion or multiple dispersions and mixed together. In the embodiment, two particle dispersion solutions are prepared: the "first particle dispersion solution" includes nano-sized polystyrene particles dispersed in deionized water, and the "second particle dispersion solution" includes nano-sized silicon dioxide particles dispersed in ethanol.

[0029] Continuing with Figure 1, which illustrates a method for preparing a porous surface with lubricant injection according to the present invention, please refer to step 12 of Figure 1 again. This involves preparing a first particle dispersion solution, including: dissolving styrene and polyvinylpyrrolidone (PVP) in ethanol; heating the styrene solution in an oil bath; slowly adding potassium sulfate (KPS) aqueous solution dropwise to the styrene solution; and continuing the heating reaction for a period of time. After the synthesized polystyrene solution is cooled and precipitated by extraction, nano-sized polystyrene particles are purified. The "first nano-sized polystyrene particles" are dispersed in deionized water (dispersion in H₂O) to maintain the nanosphere state.

[0030] Referring again to Figure 1, which is a schematic diagram of a method for preparing a porous surface with lubricant injection according to the present invention, and continuing to refer to step 12 of Figure 1, a second particle dispersion solution is prepared. The second particle dispersion solution can be prepared using the general sol-gel method to prepare silicon dioxide nanoparticles, which will not be described in detail here. It should be noted that the nano-sized silicon dioxide particles prepared by the sol-gel method are spherical, and silicon dioxide nanoparticles of different particle sizes can be prepared by adjusting the ratio of ethanol and water during the preparation process. Therefore, the "second nano-sized silicon dioxide particles" can be dried into powder first, and then dispersed in ethanol in subsequent steps.

[0031] Figure 1 is a schematic diagram of a method for preparing a porous surface with lubricant injection according to the present invention. Referring to step 14 in Figure 1, which is the "step of fixing surface particles onto a substrate," the surface particle composition is fixed onto a silicone substrate using an appropriate method. The fixing method of the present invention does not use an adhesive; that is, it uses an adhesive-free method to fix the surface particle composition onto the silicone substrate. In an embodiment, a "first particle dispersion solution" and a "second particle dispersion solution" are mixed in an appropriate ratio to form a surface particle composition. For example, a "first particle dispersion solution" with a solid content of 5% polystyrene and a "second particle dispersion solution" with a solid content of 2.5% are mixed at a volume ratio of 1:20 to obtain the surface particle composition. Next, the surface particle composition is spin-coated onto the pretreated silicone substrate and then heat-treated.

[0032] Continuing with Figure 1, a schematic diagram of the preparation method of a porous surface with lubricant injection according to the present invention, please also refer to the fixation method in step 14 of Figure 1. This involves heating the material to the glass transition temperature of polystyrene (or higher) through heat treatment to soften the "first polystyrene particles," forming a self-assembling amorphous adhesive that requires no additional introduction and is non-toxic. This adhesive then fixes the "second silicon dioxide nanoparticles" onto the substrate, forming a porous particle surface. Alternatively, the fixation method of the present invention can also be replaced by an immersion method, where the silicone substrate is immersed in the body composed of surface particles for a period of time, achieving the same result of fixing the surface particles onto the substrate.

[0033] Figure 1 is a schematic diagram of a method for preparing a porous surface with lubricant injection according to the present invention. Please refer to step 16 in Figure 1, which is the "step of forming a lubricant surface on the porous particle surface". In the embodiment, the porous particle surface formed by "first polystyrene particles" and "second silicon dioxide particles" is immersed in silicone oil for several hours, allowing the silicone oil to slowly penetrate and wet the porous particle surface. Then, the unpenetrated lubricant is removed by an appropriate method, such as a rotation method, thereby forming a continuous and stable "lubricant-wetted porous surface (SLIPS)" to achieve the effect of repelling the adhesion of foreign liquids and protein adhesion.

[0034] Figure 2 is a cross-sectional schematic diagram of a porous surface with lubricant injection according to the present invention. It is a porous surface with lubricant injection produced by the preparation method of the porous surface with lubricant injection shown in Figure 1. The substrate 21 includes metal materials, plastic materials, polymer materials, and polymer materials including silicone, polydimethylsiloxane, polyvinyl chloride, gauze (degreased cotton), and various materials such as wood.

[0035] As shown in Figure 2, a cross-sectional schematic diagram of a porous surface with lubricant injection according to the present invention, a plurality of first polystyrene particles 22 and a plurality of second silicon dioxide particles 23 are formed on the surface of the substrate 21. The first particles include: silicon dioxide particles, polystyrene particles, and poly(3-hydroxybutyrate-co-4-hydroxybutyrate), P34HB particles. The second particles also include: silicon dioxide particles, polystyrene particles, and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) particles, and the particle size is between 300 and 400 nanometers.

[0036] As shown in Figure 2, a cross-sectional schematic diagram of a porous surface with lubricant injection according to the present invention, the porous surface is formed between a plurality of first particles 22 and a plurality of second particles 23 by lubricant 24, forming a lubricant surface on the surface of the porous particles. The lubricant 24 is a combination of one or more biocompatible materials and a polymeric material that remains liquid at room temperature, including linear polysilane materials and polydimethylsiloxane.

[0037] After the present invention provides a method for preparing a porous surface with lubricant injection, the "anti-icing test" of the present invention, as shown in Figure 3A, can be performed. In this "anti-icing test," the "lubricant-wetted porous surface" is placed in liquid nitrogen for about 1 minute to simulate an extremely low-temperature freezing environment. After being removed from the liquid nitrogen, deionized water is sprayed onto the surface, causing a thick layer of frost to form. As the temperature rapidly decreases, the entire silicone plate is surrounded by frost. Then, it is placed on a heating plate at 100°C. Large areas of frost are observed sliding directly off the surface of the "lubricant-wetted porous surface." This allows for rapid observation of the ice sliding off the "lubricant-wetted porous surface," thus determining its anti-icing properties. Since freezing water requires sufficient low temperature and the presence of crystal nuclei, this "anti-icing test," while unable to prevent the formation of crystal nuclei, allows the frost formed on the surface after the crystal nuclei grow to slide off quickly, preventing frost from remaining on the surface and thus achieving anti-icing adhesion. Furthermore, during the "anti-icing test," it withstood drastic temperature changes in a very short period of time without any damage to the surface, and the "anti-icing test" can be repeated continuously, demonstrating its excellent mechanical strength and durability.

[0038] Figure 3B shows a schematic diagram of the control group in the "anti-icing test" of this invention. During the anti-icing process of the silicone board in the control group, frost could not easily slide off the surface of the silicone board without lubricating oil. Instead, it would turn from ice to water due to the temperature rise caused by heating. Although silicone is a hydrophobic material, without a sufficiently large tilt angle, the water droplets would still remain on the surface of the silicone board and could not easily slide to the bottom.

[0039] Figure 4 is a schematic diagram of the "simulated blood test" of the present invention. It uses human blood and adds heparin and hydroxyethyl starch solution (HES solution) to simulate the infusion of tubing during extracorporeal circulation, which becomes an anti-blood cell adhesion test liquid. It can be drawn up using a micropipette and dripped onto a porous surface with lubricating fluid injection of the present invention to perform the "simulated blood test". The result of the test is shown in Figure 4.

[0040] As shown in Figure 4, a schematic diagram of the "simulated blood test" is presented. The porous surface of this invention, with its rough particle surface and numerous pores that allow silicone oil to fill, forms an external protective and anti-adhesion lubricating layer for external fluids. Even when the test fluid is a complex and highly viscous solution of human blood mixed with heparin and hydroxyethyl starch, it maintains excellent self-cleaning ability and does not exhibit the tailing phenomenon seen in the control group. Instead, it retains a droplet-like shape, preventing the test liquid from adhering to the surface of the porous surface with lubricating fluid injection. This reduces blood cell rupture, increases the amount of blood returning to the patient, and reduces treatment discomfort. In contrast, in the control group shown in Figure 4, the test blood stagnates on the silicone plate surface after being dripped, exhibiting severe tailing and a slow flow rate. This causes blood cells to adhere to and break on the surface, taking a long time to reach the bottom, where they remain stagnant, even after 24 hours, eventually drying out.

[0041] In summary, the polydimethylsiloxane used in this invention is non-toxic and commonly used in bio-related materials such as contact lenses and microfluidics. This invention leverages the similarity in structural properties between silicon dioxide and polydimethylsiloxane, their ease of synthesis, and the controllable particle size, choosing silicon dioxide as the main particle structure for the coating. The polystyrene used in this invention is commonly used in medical devices, is non-toxic, and is easily synthesized; therefore, polystyrene was chosen as one of the materials. Furthermore, the silicone oil used in this invention is also polydimethylsiloxane, thus utilizing highly biocompatible silicone oil to replace fluorinated lubricants. Moreover, this invention involves spin-coating a particle dispersion of polystyrene and silicon dioxide, followed by heat treatment to form a porous particle surface without adhesive on the substrate surface. Finally, silicone oil is injected to form a lubricant surface on the porous particle surface, creating a "lubricant-injected porous surface."

[0042] This invention utilizes polystyrene to spin-coat silica to create porous particle surfaces, followed by heat treatment above the glass transition temperature of polystyrene. This heats the polystyrene to act as an adhesive between the silica and the silica sheet. Finally, silicone oil is introduced as a lubricant layer, forming a lubricant surface on the porous particle surface, successfully creating a "lubricant-injected porous surface." Furthermore, this invention does not use fluorine, which, although possessing extremely low surface energy, raises concerns about biotoxicity upon heating. Furthermore, the coating prepared by this invention possesses anti-adhesion and self-cleaning properties against common fluids and extracorporeal circulation tubing infusions. When used in medical surgery, it can reduce the rupture and damage of blood cells. This invention can remain unchanged under repeated immersion in silicone oil and anti-adhesion tests, exhibiting excellent reusability. When the surface of this invention is scratched by external force, the silicone oil can spontaneously fill the area with lower potential energy, promoting a self-healing process. It can also resist frost adhesion under drastic temperature changes, possessing outstanding mechanical strength and resistance to cold and heat.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the patent application of the present invention; all other equivalent changes or modifications made without departing from the spirit disclosed in the present invention should be included in the scope of the patent application below.

[0044] 10: Steps 12: Steps 14: Steps 16: Steps 21: Substrate 22: First particle 23: Second particle 24: Lubricating fluid

Claims

1. A method for preparing a self-healing porous surface by injecting a mixture of nano-sized polystyrene particles, nano-sized silica particles, and polydimethylsiloxane lubricant, comprising: providing a silicone substrate, wherein the silicone substrate is subjected to a cleaning, a drying, and a light treatment to repair a surface of the silicone substrate; preparing a first particle dispersion solution, the first particle dispersion solution comprising nano-sized polystyrene particles dispersed in deionized water, the nano-sized polystyrene particles having a solid content of 5%, comprising at least: dissolving styrene and polyvinylpyrrolidone in ethanol to form a styrene solution; heating the styrene solution in an oil bath, slowly adding an aqueous potassium sulfate solution dropwise to the styrene solution, and continuing the heating reaction for a period of time; cooling the polystyrene solution and extracting and precipitating the polystyrene solution to form nano-sized polystyrene particles; and dispersing the nano-sized polystyrene particles in deionized water to maintain the nanosphere state; A second particle dispersion solution is prepared, comprising nano-sized silicon dioxide particles dispersed in ethanol, the solid content of the nano-sized silicon dioxide particles being 2.5%, and comprising at least: adjusting the ratio of ethanol to water to prepare nano-sized silicon dioxide particles using a sol-gel method; drying the nano-sized silicon dioxide particles to obtain nano-sized silicon dioxide particle powder; and dispersing the nano-sized silicon dioxide particle powder in ethanol; mixing the first particle dispersion solution and the second particle dispersion solution at a volume ratio of 1:20 to obtain a surface particle composition, one of the surface particle compositions having a particle size between 300 nanometers and 400 nanometers; and spin-coating the surface particles onto a silicone substrate. A heat treatment is performed to heat the nano-sized polystyrene particles to a glass transition temperature, forming a self-assembling amorphous adhesive to fix the nano-sized silica particles onto the silicone substrate, creating a porous particle surface. The porous particle surface is then immersed in a polydimethylsiloxane for several hours, allowing the polydimethylsiloxane to slowly penetrate and wet the porous particle surface, forming a lubricant that wets the porous particle surface, thereby achieving the effect of repelling the adhesion of foreign liquids and proteins.

2. A method for preparing a self-healing porous surface for lubricant injection as described in claim 1, wherein the cleaning includes removing surface dirt and organic matter from the silicone substrate by ultrasonic vibration and washing the silicone substrate with deionized water.

3. A method for preparing a self-healing porous surface for lubricant injection as described in claim 1, wherein the light treatment comprises irradiating the silicone substrate with an ultraviolet lamp.

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