Application of the hottest fluorocarbon plasma tec

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Application of fluorocarbon plasma technology

in order to solve the problem of environmental pollution and achieve the purpose of cleaner production, plasma surface treatment technology has attracted people's attention. Plasma is another widely existing basic form of matter other than gas solid liquid three states. Under certain conditions, such as heating, external electric field, laser irradiation and other means, molecules are dissociated and ionized to form free electrons and ions. When the density of charged particles produced by ionization reaches a certain value, the ionized gas becomes an aggregation of charged particles and neutral particles, becoming a plasma. Plasma contains various ions, excited molecules, free radicals, photons and other high-energy active particles. The energy of plasma can act on the material surface through the collision of radiation, neutral particle flow and ion flow, so that the material surface can be modified

the internal electron temperature of plasma is very high, while the temperature of gas particles (ions, neutral particles, etc.) may be very low. This state of plasma is called low-temperature plasma. Using low-temperature plasma to modify materials has the following outstanding advantages: it only modifies the surface of materials without damaging the material body, and can retain the original physical and mechanical properties of materials to the greatest extent; Various gases can be used for plasma treatment, and even gases that are not reactive by themselves, such as inert gases, can also be used as reaction atmospheres; Plasma treatment belongs to dry processing, which only produces little pollution and toxic waste. Unlike traditional chemical treatment, it will cause solvent residues and other problems. It is a new technology that saves energy, water and environment

plasma treatment with fluorocarbon compounds introduces fluorine-containing groups to obtain low-energy surfaces, so that the materials can obtain various special properties, which can be used in all aspects. It is an important means of material modification

1. Application of fluorine-containing gas low-temperature plasma technology in the textile industry

compared with the traditional wet treatment process of textile printing and dyeing enterprises, plasma treatment technology, as an effective surface treatment technology, is a clean production technology with great development prospects. The research on the application of plasma processing technology in textiles at home and abroad mainly focuses on the following aspects: improving the spinning performance of wool fiber; Improve the dyeing and printing properties of the fiber; Improve the anti felting property of wool; The deepening effect of dyed fabrics; Improve the adhesion and interfacial strength between fiber and polymer matrix; Enhance the pretreatment effect of the fabric, and the use atmosphere is mostly oxygen, nitrogen, air, argon and other gases

the durable water and oil repellent multifunctional finishing of fabrics is mostly reported at home and abroad to be treated with organic fluorine resin. There are not many researches on durable water and oil repellent multifunctional finishing by using plasma treatment and introducing fluorine-containing groups

later, it is blended with polyethylene glycol (P measure the wear scar diameter eg of any one or three steel balls in the ball box after each experiment) to make an anisotropic hydrogel fiber support. The water and oil repellency of various fibers can be improved by using fluorine-containing gas plasma treatment. Yasuda used CF4 plasma to treat some fabrics of common fibers such as polyester, nylon, vinylon, cotton, nylon, wool and silk. After treatment, the contact angle of the fabric was increased to varying degrees, the surface tension was reduced, and the fabric had good water and oil repellency. Some people use fluorine-containing monomers to conduct plasma polymerization on cotton fabrics and acrylic fabrics, so that the fabrics can obtain good waterproof effect. The softness, water retention, color change, hand feel and air permeability of cotton fabrics are better than those coated with commercial scotchgad waterproof and antifouling agent

there are many gases that can be used as plasma treatment atmosphere, including the mixture of CF4, c2f4, C3F6, CF4 and H2. These gases can improve the water repellency of fabrics, and the water repellency changes with the types of fluorocarbons used, treatment time and power. Using different gases and different operating conditions to treat different fabrics, the fluorine content on the fabric surface is obviously different, and the fluorine-containing groups introduced are also different. Using CF4 as the atmosphere to treat nylon, the content of fluorine on the surface is%; With C3F6 as the atmosphere, the content of fluorine on the surface is 2 8%。 X-ray photoelectron spectroscopy (XPS) observed that fluorination occurred on the fiber surface after CF4 plasma treatment, and fluorine-containing groups were introduced. The analysis of the CL spectrum showed that -c-o-c-, -cf, -cf2 and -cf3 groups increased, while -coh and -cooh groups decreased. For different fabrics, the main groups introduced are also different, for polyester, nylon The control system of vinylon and cotton Jinan assaying universal tensile testing machine adopts DC servo electromechanical as The "power source" fabric mainly introduces -cf2 group, while the natural protein fiber wool and silk show strong -cf absorption. And the C3F6 treatment effect is better than CF4.

the durability of the treatment effect is one of the important indicators to evaluate the treatment effect. It has been reported that the fabric after plasma treatment has a time-lapse effect, that is, the hydrophilic property obtained will gradually decline after a period of time, but when the polyester fabric is treated with CF4 plasma, it is found that Even if the treated material is stored for 150 days, there is no significant change in f/c and its water repellency. It is found that the structure of using gas is an important factor affecting the durability of fabric treatment effect. When using unsaturated gas, the durability of fabric is worse than that of saturated gas. The reason may be that the gas with unsaturated structure is prone to polymerization during plasma treatment, and the combination between polymer and fabric surface is not very strong

the water repellency obtained after plasma treatment will be weakened after water washing and drying, because the fluorine-containing groups on the fiber surface are prone to overturn after water washing, and the surface tension increases, resulting in the decline of the water repellency of the fabric. If high temperature drying is used after washing, it is conducive to the recovery of water repellency

2. Plasma treatment of other materials with fluorine-containing monomers

polyester film (PET), polypropylene (PP) and other materials are now widely used. Using fluorine-containing monomer plasma to treat these polymer materials can obtain special properties and wider applications. Glowski et al. Treated PET film with c6f14 plasma and used it as biological treatment material. After plasma treatment, the material did not cause any toxic reaction, would not affect its biocompatibility, and could improve its anticoagulant performance. It was reported that plasma polymerization was carried out on the membrane material to obtain a fluorine-containing film, which can be used to separate oxygen and nitrogen. Using the mixture of C2F6 and H2 as the atmosphere, when the proportion of C2F6 in the mixture increases, the permeability of oxygen and the selectivity of the membrane are improved. There is a layer of polyimide coating on the ink cartridge nozzle of the traditional ink-jet printer, which is easy to be wetted by the ink and affect the printing effect. Some people use fluorine-containing monomer as the atmosphere. If the machine performs plasma treatment in the standby state to obtain a water and oil repellent surface, it improves the shortcomings of the traditional ink cartridge, and has applied for a number of patents. Using cf4/ch4 plasma to treat the surface of the material can also obtain flame retardant performance. XPS study shows that a highly crosslinked polymer carbon film can be obtained after methane plasma treatment. The higher the deposition rate of methane plasma is, the thicker the polymer film is, which is more conducive to flame retardation. Shi Laishun's research also confirmed that the combustion rate of polypropylene film generally decreased after being treated by methane plasma, which confirmed the flame retardant effect of carbon layer with high cross-linking effect on the surface of plasma modified polymer film

sigurdur sigurdsson et al. Treated pet and PP with CF4 plasma, and the surface energy decreased to mj/m2 after treatment. Washing with water and acetone has little effect on the hydrophobicity of the treated surface, indicating that the treated surface is relatively stable. XPS showed that the hydrophobicity increased with the increase of non-polar groups -cf2-, -cf3, and -ch2-cf2- on the surface. Some people used cf4ch4/cf4 plasma to modify the surface of pet. It was found that the mechanism of carbon fluorine mixture with different molar ratios was different, and it was divided into three regions. Region 1 (.3%cf4) was the plasma polymerization region, region 2 (83..2%cf4) played a major role in plasma polymerization, etching played a secondary role, and region 3 (96.%cf4) played a major role in etching and fluorination grafting

3. Conclusion

plasma technology can clean, quickly and efficiently change the surface properties of various materials, and has important application value in the textile industry and the field of polymer materials. Low temperature plasma treatment with different fluorocarbons can obtain special low-energy surfaces for various purposes. However, at present, there are still many problems in the application of low-temperature plasma technology in industry. For example, plasma is usually produced in vacuum, which brings difficulties to large-scale application. And the reaction mechanism of surface modification by low temperature plasma of fluorocarbons has not been clear, which limits its further application. With the improvement of plasma technology, low temperature plasma treatment with fluorocarbons will be more widely used

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