Electron-beam irradiation processing technology for food products

Non-thermal sterilization methods have been getting popular over the last decade. One of such methods is the e-beam sterilization. Based on 2005 data, 400.000 tons of food has been decontaminated by radiation. It has been reported that foods irradiated by e-beam energies up to 10 MeV does not have any harm to health. In addition, installation cost and operational costs are comparable to pasteurization.

High energy electrons destroy the DNAs of harmful microorganisms such as bacteria and viruses. Different dosages for each food type has been determined and related legislations has been made. Gamma sterilization has also similar use however, it requires protected constructions against radiation and waste management is also an important issue.  Due to these problems, e-beam sterilization plants are getting more popular. In Figure 1, an illustration of an industrial e-beam accelerator has been shown.

A Standard e-beam accelerator is composed of two main parts. First is the electron source and the other is the electron accelerator. It is possible to obtain electrons by two means. One is thermionic methods and the other is photonic methods.  Similarly, accelerator part has two options: One is DC acceleration and the other is the RF acceleration. Traditionally, in thermionic sources DC acceleration and in photonic sources, RF acceleration is used.

In Figure 2, an e-beam accelerator with photonics source and RF acceleration is shown. In a photo injector setup, electrons, which are removed from the cathode by the laser pulses, form a low energy particle cloud. This electron cloud should be forwarded towards the acceleration cavity as soon as possible. This is achieved by the electron optics formed by magnets.  Acceleration of the electrons are achieved by the acceleration cavity which is made of high conductivity metal that allows the formation of standing waves at the required electromagnetic modes such as TM010. For an effective acceleration, RF wave frequency should be multiples of the laser beat frequency.  In the system, laser power and RF profile should always be monitored in the diagnostic region. RF power measurement is achieved by the antenna placed inside the cavity. Eventually, electrons at the exit of the system, electrons are accelerated up to 10 MeV and they are easily directed towards the target material via the scanning electronics. In the following figure, the concept together with the conveyor and e-beam source is shown.

Applications of Plasma Treatment in Food Industry for Decontamination and Detoxification Purposes-Part-1

Baran ONAL-ULUSOY

Department of Food Engineering, Çankırı Karatekin University, Çankırı, Turkey.

baran@karatekin.edu.tr

OUTLINE

Brief description of food chemistry

Microbial growth on food

Foodborne pathogen microorganisms and their contamination on food

Formation of foodborne toxins and their effects on human health

   Current and emerging non-chemical decontamination and detoxification methods

Foodborne illnesses remain a major global public health concern. Every year, 2.2 million people, including 1.9 million children, die due to the consumption of contaminated food and water according to the WHO. These illnesses are caused by foodborne pathogens and occur in two ways: infection and intoxication.

Both physical and chemical properties of foods and their processing technology determine type and growth of pathogen species. Both government regulatory agencies and the food industry have shown great effort to ensure production of safe products but outbreaks are still increasing.

The major challenge of food processing is to develop innovative means of delivering high-quality, shelf-stable and safe products in the most efficient, economical and sustainable ways.Chemical methods and  thermal methods have been proposed and evaluated for the decontamination and detoxification of foods. Advantages and disadvantages of using these techniques on food and recent studies published in the literature will be discussed. 

Applications of Plasma Treatment in Food Industry for Decontamination and Detoxification Purposes-Part-2

OUTLINE

Non-chemical and non-thermal food decontamination and detoxification techniques

Advantages and challenges of plasma treatments on food decontamination and detoxification

Application of low-pressure vacuum plasma and atmospheric plasma on decontamination and detoxification of foods

Changes in some physical and chemical properties of various foods after plasma treatment

Non-chemical and non-thermal methods, such as high hydrostatic pressure, pulsed electric field, pulsed UV light, power ultrasound, plasma have been proposed and evaluated for the decontamination of foods. An emerging technology is non-thermal plasma, which may have future commercial applications for produce.

Plasma is partially ionized gases also known as highly energized fourth state of matter that contains ions, electrons, as well as reactive neutral species (radicals, and excited atoms and molecules), and sometimes with sufficient energy to break covalent bonds and/or initiate various chemical reactions.  Effect of plasma on various foodborne pathogens, yeast and molds has been studied on microbiologically contaminated artificial surfaces. However, there is a need to evaluate plasma applications and effectiveness for food decontamination and detoxification as well as their effect on food quality. Our recent efforts on decontamination of bacteria and toxin producing molds on some foods and detoxification of some toxins by using both low pressure plasma and atmospheric plasma, and the effects of these plasma treatments on food quality will be introduced. Besides, advantages and challenges of using both plasmas will also be shared.  

IMPROVEMENT OF MEDICAL TEXTILES BY PLASMA PROCESSING

Assist. Prof. Dr. Bengi KUTLU

Course Outline:

-Basic information about textile structures

-Definition and classification of technical textiles,

-Definition of medical textiles

-Classification of medical textiles

-Plasma processing of medical textiles

-Examples of plasma treatments for implantable and non-implantable medical textiles and antibacterial products

Abstract:

Textile materials can be used in many different forms, such as fibers, yarns, fabrics and finished products such as clothes, depending on the purpose of end-use. According to the publication named “Textile Terms and Definitions” of The Textile Institute, technical textiles are defined as textile material and products manufactured primarily for their Technical performance and functional properties rather than aesthetic and decorative characteristics. “Medical textiles” is one of twelve classes of technical textiles. Application areas can be classified mainly into three groups as implantable materials, non-implantable materials and healthcare materials. Among them, there are bandages, wound care products, sutures, stents, vascular grafts, plasters, artificial organs and surgical gowns.

Plasma technology is a distinguished technology to modify the surfaces of the products. In case of medical textiles, this technology can be used for room temperature sterilization (temperature is especially important for the disposable products that are made from polypropylene), obtaining biocompatibility for implantable products such as vascular grafts, functionalization of surfaces for coating by antibacterial finishing. Surface activation, functional grafting or plasma polymerization can be used to obtain these properties. 

DESIGN OF LOW TEMPERATURE- ATMOSPHERIC PRESSURE FLUIDIZED BED PLASMA REACTOR FOR FOOD DECONTAMINATION

Beyhan Günaydın Daşan¹, Mehmet Mutlu²

1. Hacettepe University, Engineering Faculty, Department of Food Engineering, Ankara, Turkiye

2. TOBB University of Economics and Technology, Engineering Faculty, Department of Biomedical Engineering, Ankara, Turkiye

The conformance of application of low pressure plasma technology on sterilization and decontamination was confirmed with the studies carried out on medical and biomedical fields by many other researchers as well as by our research group. Since this method was not adequate on large scale applications from the financial point of view, the effects of ‘fluidized bed atmospheric plasma ’  system on decontamination was investigated.

In this study a lab scale fluidized bed atmospheric plasma reactor was designed. This system was used to prove the feasibility of faster and effective decontamination process of molds that cause food spoilage and produce aflatoxin and the convenience of the method to large-scale and continuous systems. For this purpose, hazelnut, which have important place in Türkiye’s imports, was selected as ‘model food’.

In this study, a fluidized bed reactor was designed implying low temperature- atmospheric pressure plasma technology and the effect of this system on mold decontamination of model food was investigated. Fluidized bed atmospheric pressure plasma reactor system was characterized based on critical fluidization velocity, sample quantity, treatment time and plasma discharge power parameters and the decontamination process was carried out on the food contaminated in a controlled manner with the aflatoxin-producing mold (Aspergillus parasiticus, Aspergillus flavus). The fungal load was compared before and after plasma process. Parameters were optimized with chasing the decrease in fungal load. 

Outline:

1. What is biomaterial related infection

2. The significance of surface properties on biomaterial related infections

3. Plasma polymerisation as a tool for infection free biomaterials

Biomaterial induced infection has very severe consequences; such as the removal of the implant and even death. Thus, it is crucial to prevent initial bacterial adhesion on biomaterial surfaces before it leads to biofilm formation. Modifications in surgical techniques and technological advances in biomaterial design contributed to an overall decrease in biomaterial-related complications; however, the rates of biomaterial-related infections still remain a serious problem. Various methods such as antibiotic impregnation and antimicrobial polymers have been developed to prevent initial bacterial adhesion. Despite the good results reported in the literature, in practice these methods are not very feasible for commercial biomaterial production because they are expensive and/or require intensive wet chemistry. One of the most feasible options seems to be the use of a surface modification technique such as plasma polymerisation (PP) that is relatively less expensive and that use considerably less amounts of chemicals. PP technique gives the advantages of shorter reaction times, one step process and that it only changes the surface properties of the material without affecting its bulk properties.

In this lecture, a plasma polymerisation technique to reduce biomaterial induced infection risk will be described.

Design of Proteins on the basis of Material Surface Characteristics

Department of Materials Science and Nanotechnology Engineering

Department of Biomedical Engineering Department of Biomedical Engineering

TOBB University of Economics and Technology, Ankara, 06560 TURKEY

In nature, proteins control nucleation, growth, morphology, crystallography, and spatial organization of minerals and provide molecular scaffolds for the formation of hard tissues with complex and highly functional architectures. Taking advantage of the knowledge, nature has been optimizing over millions of years, one can understand, engineer, and control peptide-material interactions and exploit them as a new design tool for novel materials and systems with unique functionalities, fabricated using environmentally-benign techniques. The understanding of the physics of recognition of inorganic materials by proteins is one of the core elements of and has profound implications in biological materials science and engineering.

In this workshop, we describe lessons from biology with examples of protein-mediated functional biological materials, explain how novel peptides/proteins can be designed with specific affinity to inorganic solids using novel engineering approaches (bioinformatics, molecular dynamics and homology modeling) and give examples of their potential utilizations in technology and medicine.

OUTLINE

-  lessons from biology with examples of protein-mediated functional biological materials

- peptides/proteins which designed with specific affinity to inorganic solids using novel engineering approaches (bioinformatics, molecular dynamics and homology modeling) and examples of their potential utilizations in technology and medicine.

Atmospheric Pressure Plasma Processes for the elaboration of biomaterials

F. AREFI-KHONSARI, S. BHATT, D. BEN-SALEM, H. FAKHOURI, J. PULPYTEL

Laboratory of Interfaces and Electrochemical Systems(LISE)

UPMC, CNRS, Paris,France

FP7-KORANET Summer School on

Novel Approaches in Non-Thermal Processing of Materials

Ankara, Turkey between 23-27 June 2014

In this talk after an introduction on the possible functionalization techniques of different surfaces and the state of the art in the field of biomaterials, examples of plasma functionalization processes both by surface activation, plasma polymerization and copolymerization will be given for the elaboration of biomaterials. APPJ are very promising for fast surface functionalization of 2D but also 3D surfaces. They also present the advantage in coating plasmas to avoid the contamination of the electrodes by the coatings during the process, which is observed in planar DBD systems, and to present high deposition rates. A special emphasis will be made on the stability of the coatings for plasma coatings and surface ageing of plasma-activated surfaces. Mainly two types of APPJ will be presented a DBD one and an arc rotative pulsed  DC  jet. The former is a cold plasma while the latter is much hotter. However both can be used in the elaboration of biomaterials for different applications. Surface treatments with these two APPJ will be presented and the coatings will be compared to those obtained at low pressure.

S. Bhatt, J. Pulpytel, S. Mori, M. Mirshahi, F. Arefi-Khonsari,  Plasma Process. Polym. 2013

OUTLINE

-          an introduction on the possible functionalization techniques of different surfaces

-          the state of the art in the field of biomaterials

-          plasma functionalization processes for biomaterials; surface activation, plasma polymerization and copolymerization

Importance of Particle Shape in Nanomedicine

Fatih Buyukserin, Ph.D.

Associate Professor of Biomedical Engineering,

TOBB UNIVERSITY OF ECONOMICS AND TECHNOLOGY

Nanoparticles, such as nanospheres, tubes, and wires, have been proposed for use in various biotechnological applications including biosensing, bioseparations, and biomolecule delivery.^[1,2]Spherical nanoparticles, however, are more widely used because this shape is easy to make, and spherical particles can be synthesized from a diverse range of materials, such as liposomes, polymers, dendrimers and various inorganic compounds. Liposomal and polymeric nanospheres, in particular, are employed significantly for therapeutic applications, which have motivated numerous studies on the effect of a particle’s size on its clearance, circulation, and distribution in vivo. While these have led to insights into the role of particle size, the effect of a particle’s shape on its biological properties remains largely unknown. Recent studies are beginning to show the remarkably improved biological properties of non-spherical particles (such as increased blood circulation time) over spherical counterparts.^[3]The major reason for the limited use of non-spherical particles in biomedical applications is the lack of fabrication methods to simultaneously and precisely control the size and shape of nanoparticles.^[4]Two different approaches that use anodic aluminum oxide (AAO) structures have been introduced to address these challenges. The first one utilizes AAO as template material to produce monodisperse silica nano test tubes via surface sol-gel chemistry. These nanostructures are potential candidates for biomolecule delivery due to their controllable large inner volumes and chemically modifiable surfaces for special targeting studies.^[5]The second approach involves the creation nanoporous Si molds from AAO etching masks and the subsequent use of these molds in a nanoimprinting setup to fabricate free-standing composite polymeric nanorods with tunable lengths.^[4]Details about template and mold fabrication, particle production and potential biomedical applications will be discussed.

References:

[1]          L. E. Euliss, J. A. DuPont, et al., Chem. Soc. Rev. 2006, 35, 1095-1104.

[2]          M. Ferrari, Nat. Rev. Cancer 2005, 5, 161-171.

[3]          Y. Geng, P. Dalhaimer, et al., Nature Nanotech. 2007, 2, 249-255.

[4]          F. Buyukserin, M. Aryal, et al., Small 2009, 5, 1632-1636.

[5]          F. Buyukserin, C. D. Medley, et al., Nanomedicine 2008, 3, 283-292.

OUTLINE

- Details about template and mold fabrication

- Particle production and potential biomedical applications

Gas plasma technology in dairy separation processes to improve the performances of polymeric membranes

Hacı Ali GÜLEÇ

Trakya University, Engineering Faculty, Food Engineering Department, 22030 Edirne, Turkey

ggulec@gmail.com

Outline:

-       Membrane processes in dairy industry: Impact

-       Biofouling & antifouling: mechanisms and methods

-       Membrane fouling: Impact and protein interaction with membrane surfaces

-       Surface chemistry based hydrophylicity & hydrophobicity

-       Wetting phenomena and surface free energy theories

-       Superhydrophylic surfaces

-       Plasma interaction with surfaces: deposition, polymerization and etching

Synopsis:

In the last decade, the membrane separation processes are especially used to produce pro-longed life milk, milk concentrate before cheese production and whey concentrate, respectively. İn addition to this, these techniques have an attractive potential for fractionating the valuable components in the milk and dairy wastewaters and provide effective usage of these components. The removal of dairy wastewaters without any pretreatment cause serious environmental problems when considering the production capacity in Turkey and also worldwide. There is also great need for purification and reuse of brine in dairy industry. The application area of the membrane separation processes are limited due to natural chemical structure of milk. The main components of milk such as fat globules, several proteins and minerals tend to foul the polymeric membrane surfaces and block the pores of membrane during separation processes. This formation lowers the permeate flux and decreases the efficiency of the membrane separation processes. It is important to obtain long term  and constant membrane flux in a continuous process based on economy.  The conservation of initial permeability and selectivity is alsonecessary in a filtration application.

The aim of the lecture is to describe protein-membrane interaction during whey processing. Also, it will be mentioned that the effects of plasma treatments on the performances and efficiencies of the membrane separation processes used in dairy industry. The plasma treatment is known as an effective method to increase the surface energy of polymer by forming hydrophilic functional groups, such as -OH and -COOH. Superhydrophilic surfaces have attracted increasing interest for several of their remarkable properties, such as self-cleaning, antifogging, and enhancement of boiling heat transfer. Protein resistant surfaces are especially important for membrane separation processes. In the scope of this lecture, a novel, environment friendly and feasible method will be described not only to prevent membrane fouling but also to create new membrane structure having high selectivity and higher thermal, mechanical and chemical resistance by gas plasma technology. The effects of surface chemistry based on surface hydrophilicity and hydrophobicity on membrane foling phenomena will be discussed in details. The impact of biofouling in membrane processes will be described.Their corresponding antifouling capability is examined.The major strategies for designing surfaces that prevent fouling due to proteins, bacteria, and marine organisms are reviewed.

Considering Surface and Gas Phase Processes in Plasma Deposition

Dirk Hegemann

Empa, Swiss Federal Laboratories for Materials Science and Technology, St.Gallen, Switzerland

dirk.hegemann@empa.ch

Outline:

-       Plasma interaction with surfaces: ablation vs. deposition

-       Plasma deposition: sputtering, plasma polymerization and combinations thereof

-       Functional surfaces: electrical, optical, adhesion promoting and antibacterial properties

-       Stability of plasma deposits in aqueous environments

Synopsis:

Plasma interaction with material’s surfaces enables ablation and deposition processes depending on the gas composition and the energetic conditions. Most of all, plasma deposition yields the controlled modification of material’s surfaces such as e.g. polymers at the nanoscale. Industrial applications based on plasma deposition require reliable processes that can be transferred to production-scale reactors. For this purpose, both gas phase and surface processes should be well controlled during the deposition process.

Plasma-assisted ablation processes are used for the cleaning/activation of materials, for etching and for sputtering. While the sputtering yield is determined by the energy flux to the target material, the film growth from the sputtered atoms is also influenced by ion bombardment yielding surface diffusion, nucleation sites and densification. Thus, for example, high quality metal films can be deposited showing interesting electrical and optical properties. Using silver coatings, surface oxidation results in tarnishing at ambient air or release of silver ions in aqueous conditions. Passivation of such surfaces is thus of importance.

For plasma polymerization, gas phase processes depend on the gas composition and the energy invested per particle (plasma chemistry), while surface processes are also determined by the energy flux and the momentum transfer during film growth (plasma physics). The latter can be calculated by measuring mean ion energies and ion fluxes as well as the flux of depositing particles (corresponding to the deposition rate). Functional plasma polymers can be deposited comprising oxygen or nitrogen functional groups within a cross-linked network that determines their stability in aqueous environments. The functional group density supports adhesion such as e.g. for proteins (cell growth), attachment of chemical molecules (adaptive surfaces) or in composite materials.

Co-sputtering during plasma polymer deposition enables the incorporation of metal nanoparticles. The influence of the filling factor is investigated for the metal ion release and related antibacterial and cytotoxic properties. The latter is of interest for e.g. wound bandages, implant surfaces, sutures etc.

Finally, the potential of the presented dry, non-thermal plasma processes for industrial applications will be discussed.

POWER SUPPLY SYSTEMS
FOR ATMOSPHERIC PRESSURE NON-THERMAL PLASMA REACTORS
APPLIED FOR Biomedical and Environmental purposes

Henryka Danuta Stryczewska, Jaros?aw Diatczyk, Joanna Paw?at

Lublin University of Technology, Nadbystrzycka 38d, 20-618 Lublin, Poland
h.stryczewska@pollub.pl

Industrial plasma-based technologies for surface treatment require the non-equilibrium atmospheric pressure plasma devices. In order to assure required plasma parameters for engineering plasma-chemical processes in plasma reactors it is necessary to provide proper parameters of power supply. Therefore, power supply systems are designed for a specific type of plasma reactor. Such systems must have required power, carry adequate value and shape of current and voltage. Correctly selected power supply system decides about plasma chemistry and technological application of non-thermal plasma. Design and performance of power supply systems for dielectric barrier discharge (DBD), gliding arc discharge (GAD, mini-GAD) and atmospheric pressure plasma jet (APPJ) reactors have been discussed from the point view of their characteristics, possibility to control power transfer and efficiency.

Taking into account the plasma reactor characteristics and nature (nonlinear resistive and/or capacitive) different solutions of power supply have been presented [1-4]. Taking advantage of the transformer’s cores nonlinearity, simple, reliable, low cost and efficient power systems, especially suitable for industrial applications, can be constructed. Main disadvantage of transformers’ power supply is the relatively narrow range of voltage and/or current control. AC/DC/AC inverters can operate both in the sine voltage or sine current regime. In the voltage regime inverter is suitable to supply DBD reactor while the current regime is most suitable to supply GAD reactor. Taking into account the electromagnetic compatibility, power supply system of GAD reactor with nonlinear transformers seems to be the better solution than electronic power inverter. The proposed in the paper systems based on specially constructed transformers and AC/DC/AC inverters can fulfill requirements of industrial arc discharge reactors while representing simplicity of construction with high efficiency and reliability.

[1]   H. Stryczewska, T. Jakubowski, S. Kalisiak, T. Gi?ewski, J.Paw?at, JAOTs, 16(1): 52-62, 2013.

[2]   H. Stryczewska, J. Diatczyk, J.Paw?at, JAOTs, 14(2): 276-281, 2011.

[3]   J.Paw?at, EPJAP, 61(2): 24323, 2013.

[4]   J.Paw?at, H. Stryczewska, J. Diatczyk, T. Gi?ewski, R. Samo?, EPJAP, 61(2): 24323, 2013.

OUTLINE

-          Design, performance and proper parameters of power supply systems

-          Specially constructed transformers and AC/DC/AC inverters

Gliding arc plasma reactors

for environmental and bio-medical applications

Diatczyk Jaroslaw, Pawlat Joanna, Stryczewska Henryka

Lublin University of Technology, Poland

j.diatczyk@pollub.pl

Compact, portable, gliding arc (GA) plasma device which will be further applied for decontamination of heat non-resistant surfaces and industrial materials like PET containers, trays, pipes, conveyers, lifts, Laundromats, medical devices, etc. was developed. Bio-medical applications require non-thermal and non-equilibrium plasma at atmospheric pressure.

Glide arc (GA) reactor consisted of 2 wire or flat electrodes of variable shape, thickness and length. Cupper, silver and stainless steel were selected for the electrode materials. Inter-electrode distance can be changed and it depends on processing gas and parameters of power supply system. We use high voltage (15kV) impulse (16kHz) power supply system. Depending on the gas flow rate and gas type achieved temperatures ranged from 40 to 150^oC. Pure air, oxygen, helium, nitrogen, argon and their mixtures were used. The lowest ignition voltage had been reached in argon and helium.

Power consumption of the gliding arc discharge plasma rector and its stable operation depends on many factors [2], among which the most important are: power supply system configuration, processing gas flow rate and its chemical composition. Discharge ignition and sustaining requests properly designed power supply system.

REFERENCES:

[1]H.D. Stryczewska, J. Diatczyk, J. Paw?at, “Temperature Distribution in the Gliding Arc Discharge Chamber”, Journal of Advanced Oxidation Technologies, Vol. 14, No. 2, pp. 276-281, 2011.

[2] J. Diatczyk, G. Komarzyniec, H.D. Stryczewska, “Power Consumption of Gliding Arc Discharge Plasma Reactor”, International Journal of Plasma Environment Science & Technology (IJPEST), Vol. 5 No. pp. 12-16, 2011.

OUTLINE

-          gliding arc (GA) plasma device and its applications

-          components of GA plasma systems

-          power consumption and stable plasma formation of GA plasma reactor

APPJ for Surface Treatment and Biological Decontamination

Joanna Pawlat,Jaroslaw Diatczyk, Henryka Stryczewska

Lublin University of Technology, Nadbystrzycka 38d, 20-618 Lublin, PolandPoland

askmik@hotmail.com

RF-powered Atmospheric Pressure Plasma Jet (APPJ, Fig.1) with changeable electrodes was developed [1-4]. Device can be applied for decontamination and treatment of non-heat resistant surfaces including biological samples as homogeneous plasma of low temperature can be generated in relatively large volume as an effect of glow discharges. Working temperature of jet was measured using several methods.

Fig. 1. Atmospheric pressure plasma jet (A), power supply (B)

The most homogenous plasma was generated in gas mixtures containing argon and helium, at gas flow rates exceeding 7.5 l/min. From RF generator point of view, the most stable operation, which resulted in the lowest ratio of reflected power was achieved at frequency range 12-15 MHz (depending on the feed gas type). In dependence on the gas flow rate and the type of substrate gas, discharge plasma sizing from 10 to 20 mm in diameter and 5-15 mm in length was produced.

It was possible to decrease working temperature compromising substrate gas ratio, applied power, frequency and gas flow-rate. The best results were obtained in air at high velocity and applied RF power of 80 W. In this condition temperature was measured 2 cm from the physical outlet of the device and in the centre of the jet. Achieved ozone concentrations were low and ranged 0,82 g/m3.

REFERENCES:

[1] H. Stryczewska, T. Jakubowski, S. Kalisiak, T. Gi?ewski, J.Paw?at, JAOTs, 16(1), pp. 52-62, 2013

[2] H. Stryczewska, J. Diatczyk, J. Paw?at, JAOTs, 14(2), pp. 276-281, 2011

[3] J. Paw?at, EPJAP, 61(2), pp. 24323, 2013

[4] J. Paw?at, H. Stryczewska, J. Diatczyk, T. Gi?ewski, R. Samo?, EPJAP, 61(2), pp. 24322, 2013

OUTLINE

-          RF-powered Atmospheric Pressure Plasma Jet (APPJ)

-          Ways to obtain stable plasma with low reflected power loss and to decrease plasma temperatures

MEHMET MUTLU

Plasma Aided Biomedical Research Group, Biomedical Engineering Department

EngineeringFaculty, TOBB University of Economics and Technology, Ankara

ABSTRACT

Cold plasma modification of polymers and deposition of thin polymer films is a branch of science characterised by an increasing popularity in the last few years for the large number of new industrial processes that have been realised by its application. Plasma modified products feature “surfaces” with tailored and unusual properties, which enable their use where otherwise would be impossible to conventional materials. Plasma produces-, or plasma modified- polymers can, in fact, be considered an entirely novel class of materials with tunable properties showing e.g. chemical inertness or enhanced reactivity, hardness, variable refractive index, hydrophobicity or hydrophylicity, adhesivity, dyebility, blood compatibility, bacterial infections resistance, etc.

The field of sensing technology covers a vast area of expertise and application in various areas. The sensor is a logical element in the information acquisition chain, sensors provide information about our physical, chemical and biological environments. The rapid growth in technology and its application has created a major market for various kinds of sensing devices to maintain the high quality of the final product and simultaneously to increase the yield.

There is no doubt that chemical sensors and biosensors are fast-moving, critical technologies for industrial and biomedical marks. Sensors find wide applications in medicine (e.g. blood chemistry determinations and immunological and microbiological testing), food, agriculture, and environmental and industrial monitoring. The efforts to reduce the risk of cross-contamination and physician viability risks are opening up opportunities for the manufacturers of disposable biomedical sensors.

In this seminar, the principle and advantages of glow discharge treatment of surfaces for single layer enzyme electrode and mass sensitive immunosensor preparation will be reviewed.

OUTLINE

- principle and advantages of glow discharge treatment of surfaces for single layer enzyme electrode

- mass sensitive immunosensor preparation

Generation of Strong Pressure Wave by Pulsed Arc Discharge for

Ballast Water Treatment

Sooseok Choi

Department of Chemistry and Chemical Engineering and Regional Innovation Center for Environmental Technology of Thermal Plasma, Inha University, Incheon, Republic of Korea.

Electrical discharge in water has been received much attention in several applicationsincludingmedical treatment, sewage disposal,material synthesis,and ballast water treatment. Arc discharge generates strong pressure wave, intense ultra violet (UV) radiation and abundant active radicalswhich can kill microorganisms in sea water. In the present work, theintensities of pressure wave measured at 100 mm away from the arc generation area were compared according to electric input energy and electrode design. Positively charged capacitors with a high voltage were used to generate the pulsed arc plasma in sea water which was contained in a cylindrical tube. In order to investigate the effects of inherently conductive sea water on pulsed discharge structure and pressure wave strength, voltage and current characteristics were also measured when electrically stored energy in the capacitors was delivered to sea water through the high voltage anode.

First, therelationship between electric input energy and strength of pressure wavewas examined. Then effects of electrode design on the pressure wave were examined at a fixed input energy to produce a strong pressure wave effectively. Depending on the applied voltages, different discharge modes of a corona/glow appearance with weak pressure below 12 kV and a spark breakdown with strong pressure above 16 kV have been observed. The efficiency of pressure wave generation is about 5 times higher for the spark breakdown mode compared to the corona/glow mode. In addition, the Ce-W electrode produced stronger pressure wave than the W electrode due to its relatively low work function.