CN115073795B - A method for surface hydrophilic modification of hydrophobic polymer materials based on carbon dioxide plasma - Google Patents

Abstract

The application discloses a hydrophobic polymer material surface hydrophilic modification method based on carbon dioxide plasma, which comprises the following steps: step one: spraying plasma jet on the surface of the hydrophobic polymer material by adopting a high-pressure air plasma spray gun to obtain a cleaned hydrophobic polymer material; step two: placing the cleaned hydrophobic polymer material in a plasma treatment device, vacuumizing the plasma treatment device, then introducing a first mixed gas, controlling the gas flow, regulating the gas pressure in the plasma treatment device, and starting a power supply to perform plasma modification treatment on the surface of the polymer material after the gas pressure in the plasma treatment device is stable to obtain a pre-modified material; step three: and (3) turning off the power supply of the plasma treatment device, and standing the pre-modified material in the plasma treatment device to obtain the modified material. The surface of the polymer material treated by the method has good hydrophilicity, and can also realize the activation and reutilization of carbon dioxide.

Description

A hydrophilic modification of the surface of hydrophobic polymer materials based on carbon dioxide plasma sexual methods

Technical field

The invention relates to the technical field of material modification, and in particular to a hydrophilic modification method for the surface of hydrophobic polymer materials based on carbon dioxide plasma.

Background technique

Plasma surface treatment technology excites gas molecules with a certain amount of energy, causing the gas to dissociate into excited states such as electrons, ions, free radicals and other metastable states, which collide with the material surface, destroy covalent bonds, generate free radicals, and activate the material. surface. The activated material surface can combine with the excitation gas to generate chemically active groups on the surface. At present, plasma surface treatment technology is widely used in the electroplating, coating, and ink industries to increase the bonding force with the substrate. Some researchers have used plasma to modify the surface of bamboo and found that plasma treatment can effectively reduce the contact angle of the bamboo surface to water, but as time goes by, the contact angle of the surface will slowly recover. The applicant has also conducted research on plasma technology packaging and found that plasma can activate the surface of any material, but the activated groups will annihilate over time. Therefore, in order to obtain a material surface with better hydrophilicity, some researchers use plasma grafting technology to graft and polymerize hydrophilic monomers or polymers on the hydrophobic surface after plasma activation. The resulting material surface has Lower contact angle. Han et al. used steam generated by ionizing triethylene glycol dimethacrylate with normal pressure helium plasma to treat feldspathic ceramics. The results showed that the surface of the ceramics treated by plasma jet contained hydroxyl radicals and its hydrophilicity was improved. .

Carbon dioxide is a very stable molecule and is difficult to react after being excited. Global warming caused by greenhouse gas emissions, mainly carbon dioxide, is seriously threatening human survival and sustainable development and is one of the major global challenges currently facing mankind. At the same time, my country's current task of improving environmental quality is still severe. In recent years, many studies have focused on the adsorption and energy recycling of carbon dioxide. Among them, the research on catalytic decomposition of carbon dioxide using plasma technology has become one of the hot spots in carbon dioxide energy research. However, the current conversion rate of carbon monoxide or methane is not ideal, and the utilization rate of carbon dioxide is not high. Research has found that carbon dioxide is activated as an electron acceptor, and blending carbon dioxide with rare gases such as oxygen or argon can improve the decomposition efficiency of carbon dioxide to a certain extent. After the polymer material is bombarded by ions, it will lose electrons and generate some activated groups. It will also accelerate the decomposition of carbon dioxide and facilitate the covalent bonding of the activated carbon dioxide with the material surface, thereby forming a permanent affinity bond on the material surface. water group. This application aims to activate and reuse carbon dioxide to generate more hydrophilic groups on the surface of the material, thereby reducing carbon dioxide emissions in the environment.

Contents of the invention

The purpose of the present invention is to propose a technology for surface hydrophilic modification of vacuum plasma in a carbon dioxide atmosphere, which uses high-frequency electricity to ionize carbon dioxide, which can not only achieve hydrophilic modification of the surface of hydrophobic polymer films, but also realize the reuse of carbon dioxide. Reduce carbon dioxide emissions.

In order to achieve the above objects, the present invention provides the following technical solutions:

The invention provides a method for hydrophilic modification of the surface of hydrophobic polymer materials based on carbon dioxide plasma. The method includes the following steps:

Step 1: Use a high-pressure air plasma spray gun to spray the plasma jet on the surface of the hydrophobic polymer material to obtain the cleaned hydrophobic polymer material;

Step 2: Place the cleaned hydrophobic polymer material in the plasma treatment device, evacuate the plasma treatment device, then introduce the first mixed gas, control the gas flow, and adjust the air pressure in the plasma treatment device. After the air pressure in the plasma treatment device is stabilized, the power is turned on to perform plasma modification treatment on the surface of the polymer material to obtain the pre-modified material;

Step 3: Turn off the power of the plasma treatment device, and let the pre-modified material stand in the plasma treatment device.

Further, in step two, the first mixed gas includes carbon dioxide and the second mixed gas, and the volume ratio of the second mixed gas to carbon dioxide is (0-5): (95-100).

Further, the second mixed gas is oxygen or a rare gas.

Further, in the second step, the vacuum is evacuated until the degree of vacuum is 5-10Pa, the time of the modification treatment is 3-10min, the pressure of the modification treatment is 20-80Pa, and the power supply of the plasma treatment device is 50-300W. .

Further, in the third step, the resting time of the pre-modified material in the plasma treatment device is 30s-3min.

Further, hydrophobic polymer materials include polyethylene, polypropylene, polyester, and silicone.

Compared with the prior art, the beneficial effects of the present invention are:

According to the hydrophilic modification method of the hydrophobic polymer material surface based on carbon dioxide plasma of the present invention, the surface of the polymer material treated by the plasma has good hydrophilicity and can be used in the fields of super absorbent materials, biomedical materials, oil-water separation and other fields. . Moreover, the surface hydrophilic stability of the modified polymer material is better, and the contact angle does not change significantly over time. Compared with existing plasma surface modification technology, this method does not require polymer monomers and is less likely to cause pollution. It can also realize the activation and reuse of carbon dioxide, thereby reducing the storage of carbon dioxide in the environment. Moreover, the modification process of this method has a short reaction time and good modification effect.

Description of drawings

Figure 1 is a schematic diagram of the effect after modification in Example 1;

Figure 2 is a schematic diagram of the effect after modification in Example 3;

Figure 3 is a schematic diagram of the effect after modification in Example 4.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

The invention provides a method for hydrophilic modification of the surface of hydrophobic polymer materials based on carbon dioxide plasma. The method includes the following steps:

Step 1: Use a high-pressure air plasma spray gun to spray the plasma jet on the surface of the hydrophobic polymer material to obtain the cleaned hydrophobic polymer material;

Step 2: Place the cleaned hydrophobic polymer material in the plasma treatment device, evacuate the plasma treatment device, then introduce the first mixed gas, control the gas flow, and adjust the air pressure in the plasma treatment device. After the air pressure in the plasma treatment device is stabilized, the high-frequency power supply is started to perform plasma modification treatment on the surface of the polymer material to obtain the pre-modified material;

Step 3: Turn off the high-frequency power supply of the plasma treatment device, and let the pre-modified material stand in the plasma treatment device.

Specifically, in the second step, the first mixed gas includes carbon dioxide and the second mixed gas, and the volume ratio of the second mixed gas to carbon dioxide is (0-5): (95-100).

Specifically, the second mixed gas is oxygen or rare gas.

Specifically, in the second step, the vacuum is evacuated until the degree of vacuum is 5-10Pa, the time of the modification treatment is 3-10min, the pressure of the modification treatment is 20-80Pa, and the power supply of the plasma treatment device is 50-300W. .

Specifically, in the third step, the resting time of the pre-modified material in the plasma treatment device is 30s-3min.

Specifically, hydrophobic polymer materials include polyethylene, polypropylene, polyester, silicone, rubber and other material films, rod-shaped or three-dimensional materials.

Example 1

This embodiment discloses a method for hydrophilic modification of the surface of hydrophobic polymer materials based on carbon dioxide plasma, which includes the following steps:

S1: Place the polypropylene spunbond non-woven fabric on the operating table, use a high-pressure atmospheric plasma spray gun that can move two-dimensionally at a speed of 5m/min, and spray the plasma jet on the surface of the polypropylene spunbond non-woven fabric. The voltage is 200V, the discharge frequency is 15kHz, and the polypropylene spunbond non-woven fabric is cleaned.

S2: Arrange the cleaned polypropylene spunbond nonwoven in the plasma treatment device, evacuate the plasma treatment device to a vacuum of 5Pa, introduce CO ₂ gas, and adjust the air pressure in the plasma treatment device to 40Pa. After stabilization, start the high-frequency power supply, the processing power is 300W, and the processing time is 5 minutes.

S3: Turn off the high-frequency power supply, take out the polypropylene spunbond non-woven fabric after 1 minute, and obtain the modified polypropylene. The contact angle is measured to be reduced from 97.5° before treatment to 48.5°. One month later, the contact angle was measured to be 49.9°, as shown in Figure 1.

Example 2

This embodiment discloses a method for hydrophilic modification of the surface of hydrophobic polymer materials based on carbon dioxide plasma, which includes the following steps:

Place the ultra-high molecular weight polyethylene rod-shaped material on the operating table, and use a high-pressure atmospheric plasma spray gun that can move up and down at a speed of 10m/min and rotate at 15 ^o /min to spray the plasma jet onto the ultra-high molecular weight polyethylene rod-shaped material. On the surface, the ultra-high molecular weight polyethylene rods were cleaned at a voltage of 200V and a discharge frequency of 15kHz.

Place the cleaned ultra-high molecular weight polyethylene rod in the plasma treatment device, evacuate the plasma treatment device to a vacuum of 5Pa, and pass in a mixed gas of CO ₂ and O ₂ , in which the volume ratio of O ₂ is 5 %. Adjust the air pressure in the plasma treatment device to 80Pa. After stabilization, start the high-frequency power supply, the processing power is 250W, and the processing time is 10 minutes.

Turn off the high-frequency power supply and take out the ultra-high molecular weight polyethylene rod after 3 minutes to obtain the modified ultra-high molecular weight polyethylene rod. After immersing it in water and taking it out, a relatively uniform water film can be obtained, and the droplets will not flow down in strands. .

Example 3

This embodiment discloses a method for hydrophilic modification of the surface of hydrophobic polymer materials based on carbon dioxide plasma, which includes the following steps:

S1: Place the polyester foam on the operating table, use a high-pressure atmospheric plasma spray gun that can move two-dimensionally at a speed of 5m/min, and spray the plasma jet on the surface of the polyester foam at a voltage of 200V and a discharge frequency of 15kHz. , cleaning polyester foam.

S2: Place the cleaned polyester foam in the plasma treatment device, evacuate the plasma treatment device to a vacuum of 7Pa, and introduce a mixed gas of CO ₂ and O ₂ , in which the volume ratio of O ₂ is 2%. . Adjust the air pressure in the plasma treatment device to 20Pa. After stabilization, start the high-frequency power supply, the processing power is 50W, and the processing time is 10min.

S3: Turn off the high-frequency power supply, take out the polyester foam after 3 minutes, and measure the contact angle from 90° to 38.4°. One month later, the contact angle was measured to be 37°, as shown in Figure 2.

Example 4

This embodiment discloses a method for hydrophilic modification of the surface of hydrophobic polymer materials based on carbon dioxide plasma, which includes the following steps:

S1: Place the PTFE plate on the operating table, and use a normal pressure atmospheric plasma spray gun that can move two-dimensionally at a speed of 1m/min to spray the plasma jet on the surface of the PTFE plate at a voltage of 200V. , the discharge frequency is 15kHz, and the polyester foam is cleaned.

S2: Place the cleaned polyester foam in the plasma treatment device, evacuate the plasma treatment device to a vacuum of 5Pa, and introduce a mixed gas of CO ₂ and O ₂ , in which the volume ratio of O ₂ is 1% . Adjust the air pressure in the plasma treatment device to 60Pa. After stabilization, start the high-frequency power supply, the processing power is 300W, and the processing time is 8 minutes.

S3: Turn off the high-frequency power supply, take out the polyester foam after 3 minutes, and measure the contact angle to drop from 103° to 64°. One month later, the contact angle was measured to be 68°, as shown in Figure 3.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as illustrative and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is therefore intended that all claims falling within the claims All changes within the meaning and scope of equivalent elements are included in the present invention. Any reference signs in the claims shall not be construed as limiting the claim in question.

In addition, it should be understood that although this specification is described in terms of implementations, not each implementation only contains an independent technical solution. This description of the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole. , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (2)

1. A method for hydrophilic modification of the surface of hydrophobic polymer materials based on carbon dioxide plasma, characterized in that the method consists of the following steps: Step 1: Use a high-pressure air plasma spray gun to spray the plasma jet on the surface of the hydrophobic polymer material to obtain the cleaned hydrophobic polymer material; Step 2: Place the cleaned hydrophobic polymer material in the plasma treatment device, evacuate the plasma treatment device to a vacuum degree of 5-10Pa, then introduce the first mixed gas, control the gas flow, and adjust the plasma The air pressure in the treatment device. When the air pressure in the plasma treatment device is stable, turn on the power and perform plasma modification treatment on the surface of the polymer material. The treatment time is 3-10min, and the modification treatment pressure is 20-80Pa. Obtain the pre-modified material; the first mixed gas here includes carbon dioxide and the second mixed gas, the volume ratio of the second mixed gas to carbon dioxide is (0-5): (95-100), and the second mixed gas is oxygen or Rare gases; the power supply of the plasma treatment device is 50-300W; Step 3: Turn off the power of the plasma treatment device, and let the pre-modified material stand in the plasma treatment device for 30s-3min. 2. The method for surface hydrophilic modification of hydrophobic polymer materials based on carbon dioxide plasma according to claim 1, characterized in that the hydrophobic polymer materials include polyethylene, polypropylene, polyester, silica gel, and rubber materials. , hydrophobic polymer materials are in the form of films, rods or three-dimensional structures.