Papers by Keyword: DBD

Abstract: Vulcanized rubber surface was modified by dielectric barrier discharge (DBD) plasma system. The hydrophilic surface can be achieved in the shortly treatment and confirmed by contact angle measurement. The increasing hydrophilic group on rubber surface was monitored by Attenuated total reflectance fourier transform infrared spectrometer called as ATR-FTIR. The surface roughness was investigated to decrease from 202.13 to 82.02 nm after DBD plasma at treatment time 180s.The optimum conditions for making contact angle lower to 22 degree by DBD plasma treatment in this work were; treatment time, 15 s; input voltage on a neon sign transformer, 200 V; electrode gap, 6 mm.

Abstract: Ozone production with Dielectric Barrier Discharge (DBD) is a typical example of the applications of low temperature plasma technology. The most critical process is to inject power into the DBD reactor. But because of the characteristic of DBD reactor, the voltage and current of power supply are distorted severely and make the measurement of input power for DBD ozone reactor even hard. This paper, based on Quasi-synchronous sampling algorithm, establishes the input power measurement systems of DBD ozone reactor and achieves the online real-time monitoring input power of DBD ozone reactor. The experimental results prove that the relative errors of more than 95% is less than0.3% between power measurement system based on Quasi-synchronous sampling algorithm and the measurement data with oscilloscope.

Abstract: The deposition of coatings on the surface of carbon fiber will be helpful to their applications. However, they are unsuitable to be deposited due to their low surface free energies, poor wettability and poor adhesions. The objective of this work is to modify carbon fibers by Dielectric barrier discharges(DBD)in ambient argon . The chemical and physical changes induced by the treatments on carbon fibers surface are examined using contact angle measurements and X-ray photoelectron spectroscopy (XPS). The interfacial adhesion of CF/EP composites are analyzed by a single fiber composite (SFC) for filament fragmentation test. The contact angles of the plasma-treated samples are visibly reduced than the untreated samples. XPS results reveal that the carbon fibers modified with the DBD at an atmospheric pressure show a significant increase in oxygen-containing groups, such as C–O,C=O and O–C=O. The results of SFC tests show that the treated carbon fibers composites could possess excellent interfacial properties with mixed resins. These results demonstrate that the surfaces of the carbon fibers samples are more active, hydrophilic and rough after plasma treatments using a DBD operating in ambient argon.

Abstract: The deposition of coatings on the surface of carbon fiber will be helpful to their appli-cations. However, they are unsuitable to be deposited due to their low surface free energies, poor wettability and poor adhesions. The objective of this work is to modify carbon fibers by Dielect-ric barrier discharges (DBD) in ambient argon. The chemical and physical changes induced by the treatments on carbon fibers surface are examined using contact angle measurements and X-ray photoelectron spectroscopy (XPS). The interfacial adhesion of CF/EP composites are analysised by a single filament pull-out test. The contact angles of the plasma-treated samples are visibly reduced than the untreated samples. XPS results reveal that the carbon fibers modified with the DBD at an atmospheric pressure show a significant increase in oxygen-containing groups, such as C–O,C=O and O–C=O. The results of IFSS tests show that the treated carbon fibers composit-es could possess excellent interfacial properties with mixed resins. These results demonstrate that the surfaces of the carbon fibers samples are more active, hydrophilic and rough after plasma treatments using a DBD operating in ambient argon.

Abstract: We present a process for rapid post-discharge deposition of liquid monomer to form functional coatings at atmospheric pressure. The post-discharge polymerization of dense polyacid and polyether coatings is first depicted versus the energy density deposited by the preliminary surface treatment of polyethylene and polystyrene substrates in air Dielectric Barrier Discharge (DBD) with respect to SEM, to XPS and FTIR-ATR analysis and to polymerization yield determined by mass measurements. The paper focuses on the effect of the filamentary air DBD on surface of the polymer substrates and on post-discharge polymerization mechanism. Indeed, the grafting yield is shown to depend on the energy density deposited by DBD and on the time exposure to air between DBD and monomer deposition, controlling respectively the surface density of radicals and labile peroxides, both triggering the polymerization of vinyl precursors. Then, the effect of deposition conditions on the polymerization yield and related thickness of the functional polymer coatings is shown and special attention is paid to the stability of the coating upon washing.

Abstract: The surface properties of scaffolds are important since cell affinity is the most crucial factor to be concerned when the biodegradable polymeric material is utilized as a scaffold in tissue engineering. The surface of biodegradable non-porous poly (lactic-co-glycolic acid) (PLGA) scaffolds were treated by atmospheric pressure dielectric barrier discharge (APDBD). The wetting angle of APDBD treated PLGA were decreased from the untreated PLGA of 73° to 42°. FTIR-ATR analyses showed hydroxyl groups were not detected regardless of treated condition, but the intensities of both ether groups and carbonyl groups were increased with treatment time and oxygen flow rate. Treatment time and oxygen flux are equally effective to make the PLGA surface more hydrophilic.