Biofouling is the most important cause of naval corrosion. In order to reduce the Biofouling development on naval materials as steel or resin, different new methods have been tested. These methods could help to follow the new IMO environment reglementations and they could replace few classic operations before the painting of the small ships. The replacement of these operations means a reduction in maintenance costs. Their action must influence especially the first two steps of the Biofouling development, called Microfouling, that demand about 24 hours. This work presents the comparative results of the Biofouling development on two different classic naval materials, steel and resin, for three treated samples, immersed in sea water. Non-thermal plasma, produced by GlidArc technology, is applied to the first sample, called GD. The plasma treatment was set to 10 minutes. The last two samples, called AE9 and AE10 are covered by hydrophobic layers, prepared from a special organic-inorganic sol synthesized by sol-gel method. Theoretically, because of the hydrophobic properties, the Biofouling formation must be delayed for AE9 and AE10. The Biofouling development on each treated sample was compared with a witness non-treated sample. The microbiological analyses have been done for 24 hours by epifluorescence microscopy, available for one single layer.
Treatments with atmospheric pressure non-thermal plasma are easy to implement and inexpensive. Among them gliding
arc (GlidArc) remains rarely used in surface treatment of polymers. However, it offers economic and flexible way to
treat quickly large areas. In addition the choice of carrier gas makes it possible to bring the active species and other
radicals allowing different types of grafting and functionalization of the treated surfaces, for example in order to apply
for anti-biofouling prevention.
This preliminary work includes analysis of the surface of epoxy resins by infrared spectroscopy: the different affected
chemical bonds were studied depending on the duration of treatment. The degree of oxidation (the C/O ratio) is obtained
by X-ray microanalysis and contact angle analysis have been performed to determinate the wettability properties of the
treated surface. A spectroscopic study of the plasma allows to determine the possible active species in the different zones
of the discharge.
This paper presents the GlidArc plasma effects on some metallic surfaces often used in dentistry: zirconium, titanium and nickel – chromium alloy plates. For the experiments performed, a GlidArc reactor with two planar electrodes has been used. During the tests, the gas flow has been kept constant while the treatment time and the distance between the plasma and the sample were modified. The surfaces were analyzed using atomic force microscopy (AFM) in order to determine the surface morphological modifications induced by the plasma treatment.
This paper aims to present the evolution of the construction and performances of non-thermal plasma reactors, identifying specific requirements for various known applications, setting out quality indicators that would allow on the one hand comparing devices that use different kinds of electrical discharges but also their rigorous classification by identification of criteria in order to choose the correct cold plasma reactors for a specific application. It briefly comments the post-discharge effect but also the current dilemma on non-thermal plasma direct treatments versus indirect treatments, using plasma activated water (PAW) or plasma activated medium (PAM), promising in cancer treatment.
Corrosion in marine environment is a complex dynamic process influenced mainly by physical chemical, microbiological and mechanical parameters. Times for maintenance related to corrosion are greater than 80% of the total repair. Reducing this cost would be a significant saving, and an effective treatment can reduce times related to ships repairing. Biofouling is a main cause of corrosion and its formation contains four steps. To inhibit biofouling it is proposed a treatment based on non-thermal plasma produced by GlidArc, which can be applied before the immersion of small boats in the sea, as well as cleaning treatment of the hull after a period of time. This work presents the microbiological results of treatment of metal surfaces (naval OL36 steel) with GlidArc technology, according to the first, respectively the second phase formation of biofouling. Samples of naval steel were prepared with three specific naval paints and before the treatment have been introduced in seawater. Microbiological results have been compared for two types of treatments based on GlidArc. In the first case the painted samples are submitted to direct action of non-thermal plasma. In the second case the plasma produced by GlidArc technology is used to activate a solution (plasma activated water = PAW) and then the samples are introduced into this water.
Corrosion in marine environment is an actual problem, being a complex dynamic process influenced mainly by physical, chemical, microbiological and mechanical parameters. Around 70% of the maintenance costs of a ship are associated with the corrosion protection. Times for maintenance related to this phenomenon are greater than 80% of the total repair. Reducing this cost would be a significant saving, and an effective treatment can reduce times related to ships repairing. Biofouling is a main cause of corrosion and for its reduction different methods could be applied, especially in the first part of its production. The atmospheric pressure non-thermal plasmas have been gaining an ever increasing interest for different biodecontamination applications and present potential utilisation in the control of biofouling and biodeterioration. They have a high efficiency of the antimicrobial treatment, including capacity to eradicate microbial biofilms. The adhesion microbial biofilm is mainly influenced by presence of bacteria from the liquid environment. That is why this work concerns the study of annihilation of maximum amount of bacteria from sea water, by using GlidArc technology that produces non-thermal plasma. Bacteria suspended in sea water are placed in contact with activated water. This water is activated by using GlidArc working in humid air. Experimental results refer to the number of different activated and inactivated marine organisms and their evolution, present in solution at certain time intervals after mixing different amounts of seawater with plasma activated water.