When PET is exposed to O2 plasma gas, atoms or fragments are attached to the polymer's chain (figure 4.1). On the surface, as oxygen species incorporate into the sample's surface, O2 concentration on it increases, different functional groups form, the surface becomes more hydrophilic, and cell adhesion is enhanced [222, 224, 225].
Full Answer
What is the contact angle of pet after oxygen plasma treatment?
After the oxygen plasma treatment for 5 s, the contact angle of PET decreases to 31° as a result of surface modifications cause by the plasma treatment. For the treatment time of 20 s, the contact angle decreased from 31° to 7°.
How long do hydrophilic devices last after second oxygen plasma treatment?
Devices treated with the second oxygen plasma of 100 and 200 s can only retain the hydrophilicity (contact angle of less than 90°) for about 3 h after exposure to air. However, with a treatment time from 300 to 500 s the devices remain hydrophilic and never fully regain their hydrophobicity during the time period of our investigation.
How does hydrophilic plasma treatment work?
Then, to begin the hydrophilic treatment, a precursor gas is inserted into the chamber where the combination of energy and a low-pressure causes the gas to ionize and become plasma. The excited plasma ions collide with the surface, microscopically changing the geometry of the surface.
What are the benefits of plasma treatment for pet?
The plasma treatment provides a reduction in the contact angle of fiber surfaces compared to the untreated fibers; consequently, this increases the superficial energy and the work adhesion of the PET fibers.
Why the surface of PDMS turns hydrophilic after oxygen plasma treatment?
Oxygen plasma treatment has been used extensively by many in the fabrication of PDMS microfluidic devices. The treatment of oxygen plasma on PDMS introduces polar functional groups12 which is mainly the silanol group (SiOH). This group changes the surface properties of PDMS from being hydrophobic to hydrophilic.
Does plasma treatment increase hydrophilicity?
Plasma treatment is one of the most widely utilized surface treatment methods to improve the hydrophilicity of the surfaces.
How does plasma treatment increase surface energy?
Plasma treatments aim to convert low energy surfaces to higher energy surfaces by removing hydrogen from the surface and attaching oxygen-containing species in its place. Other 'functional groups' can also be formed at the surface to give different and interesting properties.
How does oxygen plasma treatment work?
Plasma cleaning removes organics contamination through chemical reaction or physical ablation of hydrocarbons on treated surfaces. Chemically reactive process gases (air, oxygen) react with hydrocarbon monolayers to form gaseous products that are swept away by the continuous gas flow in the plasma cleaner chamber.
How do you increase hydrophilicity?
To enhance hydrophilicity, the introduction of nanoparticles into polymeric membranes has been proven to be effective. The nanoparticles mixed into the polymeric membrane casting solution mainly include TiO2, SiO2, Mg(OH)2, ZnO, carbon naotubes, and boehmite nanoparticles.
What is hydrophobic recovery?
Modified surfaces are subject to changes during storage and the basic change observed is a decrease in their hydrophilicity, observed by a decrease in the value of surface free energy and an increase in the contact angle with water [42,77,78]. This phenomenon is called hydrophobic recovery.
How does plasma surface treatment work?
Plasma treatment is the process by which gas is ionized in a vacuum chamber to form plasma and alter the surface of a material. The plasma improves bonding, printing, coatings and primers; this is also known as increased wettability. The process is performed in a plasma chamber under vacuum pressure.
How does plasma surface modification work?
Any process by which a product's surface is modified to accept either a bond or an ink for printing is commonly referred to as plasma surface modification. These processes are used to make an object hydrophilic (wettable). A hydrophobic surface will repel water and is considered non-wettable.
How does plasma exchange work for GBS?
Plasma exchange (plasmapheresis). The blood cells are then put back into your body, which manufactures more plasma to make up for what was removed. Plasmapheresis may work by ridding plasma of certain antibodies that contribute to the immune system's attack on the peripheral nerves.
Why is plasma used in vacuum?
The vacuum plasma process avoids damage to materials as it is a controlled, low temperature process with low energy densities. The plasma energy is highly efficient because the vacuum pressure reduces recombinations, and increases the mean free path length of the particles resulting in higher ionic kinetic energies.
What is oxygen plasma serum?
Oxygen Plasma reduces lines and wrinkles, treats abnormal skin conditions and beautifies the skin. It “mimics” the blood's ability to carry oxygen and active substances into cells. It transports oxygen to tissues and triggers formation of collagen and elastin.
Why plasma cleaning is important?
Plasma cleaning removes organic contaminants and prepares surfaces for subsequent processing through the introduction of chemical functional groups. Benchtop plasma cleaners tune surface chemistry quickly and easily, without hazardous wet chemicals.
Abstract
Prosthetic composite is a widely used biomaterial that satisfies the criteria for application as an organic implant without adverse reactions. Polyethylene therephthalate (PET) fiber-reinforced composites have been used because of the excellent cell adhesion, biodegradability and biocompatibility.
1. Introduction
In composites, the reinforcement fibers sustain almost all of the applied tensile load whereas the role of the matrix is to adhere to the fibers, protect the fibers, and transfer the load through the interface [1].
2. Experimental
PET fibers with a filament diameter of about 13 μm and elastic modulus of 14 GPa were provided by Montefiber Spa (Acerra, Naples, Italy). The PET filaments were treated in a cold plasma reactor as shown in the schematic diagram of Fig. 1.
3. Results and discussions
Table 1 shows the contact angle ( θ) values for untreated PET and for oxygen-plasma-treated PET, the surface energy values and the work adhesion values for treatment times from 5 to 100 s.
4. Conclusions
The plasma treatment provides a reduction in the contact angle of fiber surfaces compared to the untreated fibers; consequently, this increases the superficial energy and the work adhesion of the PET fibers.
Acknowledgments
The authors thank Mrs. Maria Lúcia Brison de Mattos, INPE São José dos Campos, for scanning electron microscopy characterization. The support provided by FAPESP through the process number 97/01160-7, is acknowledged.
Why is hydrophilization not stable?
The main reasons for the recovery have been identified as being the reorientation of the surface layer, or the migration of the polymer chains from the bulk of the polymer to the surface or from the surface to the bulk.
How does plasma treatment affect the surface of a polymer?
In a plasma treatment process, the surface is placed in a chamber under vacuum and bombarded by ionized gas. The ionized gas will induce chemical reactions at the surface of the material being treated, changing its surface energy. Typically, polymer surfaces exposed to oxygen or nitrogen plasmas become more hydrophilic due to formation of high energy surface groups in reactions between the native surface groups of the polymer and the reactive plasma species. In addition to surface chemistry, plasma treatment also often affects the surface topography. This means that in some cases, the surface roughness needs to also be taken into account when wettability of the surface is evaluated.
Most recent answer
While I cannot directly speak towards oxygen plasma, low pressure atmosphere plasma tends to destroy the conductivity of our PEDOT:PSS films after 1 minute. It works great for ZnO films, though.
Similar questions and discussions
What is the drop casting method details , advantage and disadvantage of this method , and what is maximum thickness of films can be given?
What happens to the surface during hydrophilic treatment?
Specifically, during a hydrophilic treatment, the surface undergoes oxidation and the bombarding plasma ions form hydroxyl groups on the surface.
What is hydrophilic treatment?
Hydrophilic Treatment - Increasing surface energy and wettability • Changing surfaces. One very important application of plasma technology is the hydrophilic treatment. This procedure is done to modify surfaces to have a strong attraction to water. This is the opposite of hydrophobic treatments which make surfaces repel water.
How does Thierry Plasma work?
Thierry can use its low-pressure plasma systems to perform hydrophilic treatments on objects of various sizes and shapes. The target object is placed within an airtight chamber. Next the pressure of the chamber is lowered by using a vacuum to remove all of the air.
Is water a hydrophobic material?
Some materials are naturally hydrophobic, meaning water beads up into droplets and it does not spread out evenly onto the surface. This can be problematic if you want to paint this surface or you want to attach something to this surface because paints and glues will not adhere well to it.