Effect Of Argon Plasma Treatment Research Articles

Effects of argon plasma treatment on surface characteristic of photopolymerization PEGDA–HEMA hydrogels

AbstractThe aim of this research was to determine the influence of argon plasma treatment condition on the surface properties of poly(ethylene glycol) diacrylate (PEGDA)–hydroxyethly methacrylate hydrogel films, a kind of scaffold materials for tissue engineering. The changes of surface properties have been evaluated by contact angles, X‐ray photoelectron spectra (XPS), and scanning electron microscopy (SEM). From the contact angle measurements of different liquids, the surface free energy of the hydrogel was calculated according to approaches by Owens–Wendt–Kaelble. Results showed that the contact angle of the hydrogel to water decreased remarkably after argon plasma treatment, which was caused by the changes in morphology (SEM images) and chemical composition (XPS results) of the argon plasma‐treated surface. The surface free energy increased with the increase of the argon plasma treated time and power, and these increasing was mainly due to the increase of polar component. The XPS results confirmed that plasma oxidation reaction produced oxygen‐containing functional groups onto the surface. This functional group played an important role in increasing the hydrophilic properties of the hydrogel. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Effects of argon plasma treatment on the interfacial adhesion of PBO fiber/bismaleimide composite and aging behaviors

This paper is concerned with the influence of argon plasma on the interfacial adhesion of PBO fiber/bismaleimide composites and aging behaviors. The interlaminar shear strength (ILSS) was greatly increased to 62.3MPa with an increase of 39.7% after treatment for 7min at 80Pa, 200W. A small amount of O and N atoms was incorporated onto the fiber surface, but the plasma caused C–O bonds to break and generated OC–N groups. The fiber surface roughness increased, contributing much to the wettability. However, long-time treatment excessively destroyed the inherent and newly created structures. The SEM images suggested that the fracture shifted from the interface to the matrix. The modification effects degraded with storage time in the air and the ILSS decreased to approximately 54.0MPa after 10–30 days. The composite had low water absorption of 2.0wt% and a high retention of 90% in the ILSS at moisture conditions.

Effect of argon plasma treatment on the PTC and NTC behaviors of HDPE/carbon black/aluminum hydroxide nanocomposites for over-voltage resistance positive temperature coefficient (PTC)

In this investigation, carbon black and inorganic flame retardants were added into high density polyethylene (HDPE) to produce an over-voltage resistance positive temperature coefficient (PTC) composite film. The results of this study indicated that the plasma treatment enhanced the surface activity and the structural completeness of HDPE, which enhanced the PTC intensity of the composite. As HDPE was treated by plasma with 40 W for 3 min, the PHDPE possessed the maximum free radicals of 0.958 × 10 − 6 mol g − 1 , which coincided with the result of gel content (43.98%) of PHDPE. In addition, it was found that the effective cross-linking method of PHDPE with initiator (DCP) and 60Co γ-ray radiation was better than the traditional radiation cross-linking method in cross-linking the structure of the composite, the former reduced the radiation dosage (was smaller than 20 Mrad) greatly to increase the PTC intensity of the composite obviously, and to eliminate the NTC effect of the composites fully. The composite of P(403)C33.7A28D2-20 possessed good PTC intensity (6.07 orders of magnitude) in all composites, passed the over-voltage resistivity test successfully, and possessed good structural stability. In accordance with the results of the thermal expansion coefficient ( α) of TMA measurement, it could be found that the CTE was possessed at the highest and a fundamental relationship exists between the PTC behavior and thermal expansion coefficient ( α).

Effect of Argon Plasma Treatment on Surface-Enhanced Raman Spectroscopy of Polypyrrole Deposited on Electrochemically Roughened Gold Substrates

In this work, polypyrrole (PPy) films were electrodeposited on electrochemically roughened gold substrates modified by argon plasma treatment. First, a gold substrate was roughened by a triangular-wave oxidation-reduction cycle (ORC) in an aqueous solution containing 0.1 N HCl. Then the roughened gold substrate was further treated by argon plasma. Encouragingly, the surface-enhanced Raman scattering (SERS) spectroscopy of polypyrrole electrodeposited on this roughened gold substrate modified by argon plasma treatment exhibits a higher intensity by 8-fold, as compared with the SERS of PPy electrodeposited on an unmodified roughened gold substrate. Meanwhile, the electropolymerization for pyrrole monomers occurring on the modified roughened gold substrate is easier. Also, the nucleation and growth of electropolymerization of pyrrole monomers on the modified and unmodified gold substrates are different.

Formation of thermally stable Ni monosilicide using an inductively coupled plasma process

The effect of argon plasma treatment on the structural and electrical properties of Ni silicides has been investigated. Electron-beam-evaporated Ni films on Si substrates are Ar plasma-treated by an inductively coupled plasma (ICP) reactor. For silicidation reactions, all the samples with and without the Ar plasma treatment are rapid-thermal annealed (RTA) at temperatures of 500–750°C in a nitrogen ambient. It is shown that the Ar plasma-treated samples produce better electrical and structural properties across the whole temperature range as compared with the untreated samples. It is further shown that the Ar plasma-treated samples contain nitrogen, which plays an important role in improving the morphological stability and the electrical properties of the silicide films.

Effect of argon plasma treatment on conductivityof sol-gel fabricated Sb-doped SnO 2 thin films

The sol-gel method is applied to the fabrication of antimony-doped tin dioxide thin films using SnCl4·4H2O and SbCl3 precursors. The effect of argon plasma treatment on the spin on fabricated thin films is studied as a function of the plasma treatment time. Changes in electrical conductivity are measured by a linear four-point probe method. The maximum increase in electrical conductivity is found to be 290%, from 138 to 400 S/cm, and the argon plasma reaction response time for the conductivity increase is fast. Finally, the reasons and mechanism for the noticeable resistivity decrease are discussed.

Infrared studies of hard hydrogenated amorphous carbon (aC:H) film and the effect of argon plasma treatment

The hard hydrogenated amorphous carbon (aC:H) films were deposited on both sides of well polished germanium (Ge) substrate by RF plasma decomposition of benzene vapours. Infrared spectroscopy was used to measure the transmission and Sp 3/Sp 2 ratio of diamond-like carbon (DLC) film as a function of plasma treatments. It has been demonstrated that the partial etching of aC:H film by argon plasma treatment may be a suitable process (1) to improve the film quality and also (2) to tailor at required wavelengths the infrared transmission of aC:H coated Ge optics.

Argon plasma treatment of glass surfaces

The effect of argon plasma treatment of glass surfaces is studied by FTIR and SEM. The argon plasma on cleaned glass surfaces resulted in increased surface area due to microetching and surface rearrangement of the silicate network as indicated by the observed changes in the Si-O stretching infrared absorption. The result was a relative increase in surface hydrophilicity which could be optimized by the plasma reaction conditions. The etching action of the argon plasma on the substrate surfaces facilitated the removal of the micrometre thick sizing from the commercial fibres accompanied by little loss in tensile strength. Plasma was also used to graft selected monomers to the surface of glass fibres for enhancement of bond compatibility in a composite system. This grafting treatment was followed by an argon etching step. The argon plasma action on the coated surfaces improved the wettability further and increased the sur face area. Changes in surface chemistry that accompanied the argon etching treatment were very subtle in the case of the plasma polymer of allylamine, but proved significant in the case of the plasma polymer of hexamethyldisiloxane. On the latter surfaces, rearrangement of the siloxane (Si-O-Si) bonds to silylmethylene (Si-(CH2) n -Si) groups is suggested.