Plasma processes under low and atmospheric pressure. O.Kylián, J. Hanuš, A. Choukourov, J. Kousal, A. Kuzminova, P. Solar, A. Shelemin, H. Biederman Charles University in Prague Faculty of Mathematics and Physics
Who we are? What is plasma? How can be plasma used for surface modification? Plasma treatment of polymers Sterilization Thin film deposition Nanostructured coatings Nanoparticles
Who we are? Faculty of Mathematics and Physics ~ 1000 student of Physics 14 departments Department of Macromolecular physics Charles University in Prague has more than 7,500 employees Over 51,000 students 17 faculties 5 researchers 8 students (6 PhD)
Ar + H 2? Ar H 2 Ar H 2 Classical Plasma main: Ar, H 2 10-3 -10-6 : H, H *, Ar *, Ar m*, Ar +, Ar 2+, H +, H 2+, H 3+, ArH +,... e - Advantage: Rich physics and chemistry! Disadvantage: Rich physics and chemistry! No thermal equilibrium! T n 0.03eV, T i 0.1eV, T e 1eV +fast (>10eV) ions and electrons Bogaerts et.al. 2002
Low pressure plasma Atmospheric pressure plasma glow discharge DBD plasma Plasma is a complex mixture of electron, ions, neutrals, radicals, excited species. Plasma emits radiation in wide spectral range. Plasma interacts with solid surfaces and may change their properties (chemical composition, morphology, bioresponsive properties etc.)
Plasma is a complex mixture of electron, ions, neutrals, radicals, excited species. Plasma emits radiation in wide spectral range. Surface modification Surface cleaning Surface sterilization Deposition of thin films Deposition of nanostructured coatings Deposition of nanocompoiste materials Biomedical applications Advantages: Biomedical applications Photovoltaic, Fuel cells Barrier and protective coatings Possibility to process virtually any substrate material Fast, cost-effective, environmentally friendly High flexibility
DBD plasma 30 W 1 atm air 1 plasma treatment C-C C-C C-H Intensity [a.u.] Intensity [a.u.] O-C=O C=O C-C C-N 292 290 288 286 284 282 280 Binding energy [ev] 292 290 288 286 284 282 280 Binding energy [ev] 5 mm 5 mm DBD plasma may change surface energy, chemical composition as well as morphology of polymers.
Improved metallization of polymers Covalent immobilization of biomolecules Sheet resistance [ ] 10 6 10 5 10 4 10 3 10 2 10 1 10 7 Untreated DBD pre-treated Intensity [arb. units] CF 3 CF 2 CF PTFE C-O 10 0 30 40 50 60 70 80 Deposition time [s] Improved biocompatibility BeforeDBD 1 DBD Intensity [arb. units] CF 3 CF 2 CF C=C-O O=C-N PTFE + DBD + BSA + SDS wash C-N C-O C-C C-H Ostoblast-like cells SAOS Intensity [arb. units] C=C-O O=C-N BSA C-N C-O C-C C-H Endotel HUVEC 296 294 292 290 288 286 284 282 280 Binding energy [ev] 3 days after seeding
By means of plasma it is possible to sterilize/decontaminate surfaces. Untreated Ar/N 2 20:2 Height [nm] 0 10,00 20,00 H 2 O 30,00 40,00 50,00 Non-treated Oxygen plasma Ar/O 2 /N 2 20:1:1 Ar/O 2 20:2 Effect on proteins 100 mm 60,00 70,00 80,00 Effect on bacterial spores Highly competitive with other sterilization methods!!! Non-treated Effect on endotoxins Plasma treated O.Kylián et. al. J.Phys.D: Appl. Phys 41, 2008, Art. No 095201 Kylian and Rossi. Phys. D: Appl. Phys. 42 (2009) 085207 Kylian et.al. Plasma Process. Polym. 2011, 8, 1137 Fumagalli et. al. J. Phys. D: Appl. Phys. 45 (2012)
Plasma may be used for deposition of thin films of metals, metal-oxides as well as plasma polymers. c PS W Sh PS c P M
Non-fouling PEO-like thin films a) evaporated without plasma PEO PEO + UV b) 1W c) 10W d) 120W PEO + autoclave PEO + dry heat e) 200W C-O C-C, C-H C=O O-C=O 290 288 286 284 282 Binding energy, ev It is possible to fabricate non-fouling PEOlike coatings that withstand UV light sterilization. A. Choukourov et al. Plasma Process. Polym. 2012, 9, 48 A. Artemenko et. al. Thin Solid Films 2012, 520, 7115
Amino-rich thin films TiAlV TiAlV + Nylon sputtered in Ar It is possible to fabricate coatings that promote cells growth. O. Kylian et al. J. Phys. D. Appl. Phys. 2009, 42, 142001 A. Artemenko et. al. Surf. Coat. Tech. 2011, 205, S529 TiAlV + Nylon sputtered in mixture nitrogen-hydrogen
Barrier a-c:h coatings 100x better barrier properties of PET!! Barrier improvement factors 100 10 1-400 V -200 V 0 20 40 60 80 100 120 Thickness [nm] Thin a-c:h films may significantly improve barrier properties of polymeric foils. O. Polonskyi et al. Thin Solid Films 2013, 540, 65
(Bio)sensing Ag columns Substrate a Magnetron M. Subr et al. J. Nanomat. in press. SERS spectra of three free-base porphyrins Concentrations <10-6
Power <1 Pa ~100 Pa Gas inlet Solar et al. Surface Coat. Technol. 2011, 205, S42 Drabik et al., Plasma Proces Polym, 2011, 7, 544 Kylian et al., Material Letters 2012, 79, 229 Polonskyi et al., J. Phys D. Appl. Phys. 2012, 45, 495301 Kylian et al. Thin Solid Films 2014, 550, 46 Solar et al. Vacuum 2015, 111, 124.. Pt Cu Ag Au Ti Al C:H C:H:N
Overcoating nanoparticles by plasma polymer Step 1 Step 2 Power Power Gas inlet Gas inlet As a source of the overcoat material may be used PECVD or magnetron sputtering.
It is possible to control independently surface roughness and surface chemical composition. We can prepare nanorough surfaces e.g. for faster osseo-integration or water repellent character Ti C:H NPs + Ti
dielectric barrier discharge (typical): 20 W, 23 khz, 15 kvpp, substrate(glass) -electrode gap 1.5 mm monomer: titanium tetraisopropoxide (TTIP), 0.5 mass% in gas (N 2, air) gas flow: 0.7-2.5 slm a) 11 W/slm b) 14 W/slm c) d) 8 W/slm 43 W/slm SEM images of the films deposited in N 2 at various Yasuda parameter - a) 11 W/slm (8W, 0.7slm) b) 14 W/slm (20W, 1.4slm) c) 8 W/slm (20W, 2.5slm) d) 43 W/slm (30W, 0.7slm) b) - cross section A. Shelemin, A. Choukourov, J. Kousal, D. Slavinska, H. Biederman: Nitrogen-Doped TiO2 Nanoparticles and Their Composites with Plasma Polymer as Deposited by Atmospheric Pressure DBD, PLASMA PROCESSES AND POLYMERS 11, 9 (2014) 864-877
Plasma is versatile tool for surface modification and for deposition of thin functional coatings. By means of plasma it is possible to tailor surface properties of solid objects. Possible applications include: Biomedical applications (Bio)sensors Barrier coatings Surfaces with controllable wettability etc.
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