Exploring the Use of DLC Diffusion Barrier & Corrosion Protection Coating (Nano Contacts) in Packaging

Size: px

Start display at page:

Download "Exploring the Use of DLC Diffusion Barrier & Corrosion Protection Coating (Nano Contacts) in Packaging"

Jordan Tucker
6 years ago
Views:

1 Exploring the Use of DLC Diffusion Barrier & Corrosion Protection Coating (Nano Contacts) in Packaging Prof. Dr Eva Maria MOSER

2 Content Exploring the Use of DLC Diffusion Barrier & Corrosion Protection Coating (Nano Contacts) in Packaging v v v v v Production of PE-CVD thin films Sustainable DLC diffusion barrier layers Adjustable wettability of DLC diffusion barrier layers: Developments in nano-polar coating for anti-fogging, easy to clean, and adhesion promoter onto polyolephins Corrosion protection by embedding active nano contacts in sustainable DLC diffusion barrier layer Impact of nano-crystalline domains of titania (TiO 2 *) and imbedding of nano-clusters onto antimicrobial effects

metallic containers and on lids Actual EU project FLEXIFUEL: 900 Al-plates coated for heat exchange prototype TiO2*

3 Motivation: Functionalization of sustainable packaging Advanced DLC diffusion barrier Surfaces of everyday life products often miss - long life durability - specifically desired functionality Titania* Replacement of varnish in metallic containers and on lids Actual EU project FLEXIFUEL: 900 Al-plates coated for heat exchange prototype TiO2* anti-germ TiO2* barrier (UV & gas) *TiO2 with photocatalytic activity Packed. The 6th Global Summit, June Amsterdam

Production of plasma coatings: Advanced DLC and Titania*

web width of 630 mm Production of TiO 2 * coatings onto flat

reduced pressure PE-CVD and PVD processes at ambient temperature

4 Production of plasma coatings: Advanced DLC and Titania* Upscaled plasma process: 30 cm Pilot R&D plasma coater with a web width of 630 mm Production of TiO 2 * coatings onto flat substrates at atmospheric pressure PVD &PE-CVD processes at reduced pressure PE-CVD and PVD processes at ambient temperature PVD: Physical Vapour Deposition PE-CVD: Plasma Enhanced Chemical Vapour Deposition

5 Why plasma coatings? +/- Criteria Sol-Gel PECVD incoat/ipi Methods in general in particular Investment coating equipment Chemicals (price, amount, toxicity) Sustainability (process & coating) Dry process, cycle interruption Ambient process temperature Adhesion (ev. plasma pretreatment) Specific coating structures Resistant, durable thin films Adaptation of established processes in manufacturing: Ø Nano structuring of the coatings Ø Encapsulation of the nano particles

6 Basic properties of DLC: Diamond Like Carbon DLC diffusion barrier layer: ighly cross-linked and inherently flexible hydrocarbon thin film I: diamond-like sp 3 > sp 2 ; C > II: graphite-like sp 3 < sp 2 ; C > III: polymer chains sp 3 > sp 2 ; C < Amorphous DLC layer of 70 nm

Functional testing of coated PET and CPP Coated PET/CPP O2-Perm. 0% r.h. [ml/m 2 dbar] O2-Perm. 85% r.h. [ml/m 2 dbar] 2O-Permeability 90% r.h. [g/m 2 d] Stretch failure [%] PET: DC/RF/Gz 1.0-1.2 ±.

7 Functional testing of coated PET and CPP Coated PET/CPP O2-Perm. 0% r.h. [ml/m 2 dbar] O2-Perm. 85% r.h. [ml/m 2 dbar] 2O-Permeability 90% r.h. [g/m 2 d] Stretch failure [%] PET: DC/RF/Gz ± ± ± ±.2 PET: Web coater ± ± ± ±.2 ydrophobe/pet phob/phil/pet < 1.0 ±.2 < 1.9 ±.2 < 0.8 ±.2 < 0.7 ±.2 < 0.2 ±.2 < 0.2 ±.2 > 2.5 ±.2 > 4.7 ±.2 ydrophobe/cpp phob/phil/cpp 40 ±.2 27 ± ± ± Ref.: PET 12 µm < ±.3 < 93.0 ±.3 < 20.4 ±.3 - Ref.: CPP 75 µm Barrier effect is enhanced in humid conditions due to the hydrophobic feature of DLC contrary to SiO 2 coatings Manufacturing of SiO 2 /DLC barrier coatings for PET bottles > bottles/hour à tubes

8 Direct contact of DLC with content CPP/PET film plasma treated 3 wt% acetic acid (2h@90 C, 10d@40 C) 95 vol% ethanol (4h@60 C, 10d@40 C) isooctane (2h@60 C, 2d@20 C) Ref: CPP/PET < 1 mg/dm 2 < 1 mg/dm 2 < 4 mg/dm 2 wincoat CPP < 1 mg/dm 2 < 1 mg/dm 2 < 1 mg/dm 2 Phil /CPP < 1 mg/dm 2 < 1 mg/dm 2 < 1 mg/dm 2 Phil /CPP < 1 mg/dm 2 < 1 mg/dm 2 < 1 mg/dm 2 Phob /CPP < 1 mg/dm 2 < 1 mg/dm 2 < 1 mg/dm 2 Welding-peeling properties: Global migration according to EU guidelines 2002/72/EG (detection limit: <1 mg/dm 2, tolerance limit: <10 mg/dm 2 ) ydrophobic DLC ESR and fluorescence spectroscopy; DLC coating: food for germs (10 20 Spins/cm 3, g-value: (11 Gauss): ydrophilic DLC à no free radicals in DLC à no interaction, no migration

cast-polypropylene is stable: à no «hydrophobic recovery phenomenon»

9 Stable polyolefin surface due to nano structuring AFM images of plasma treated cast polypropylene The surface of the plasma treated cast-polypropylene is stable: à no «hydrophobic recovery phenomenon» à no additives / no VOC s at surfaces à CPP is printable and can be coated

Additional functionality: Structuring of polymers AFM-image of plasma nano structured CPP à stable, non-restructuring surface SEM-image of CPP with micro structures produced by hot embossing

10 Additional functionality: Structuring of polymers AFM-image of plasma nano structured CPP à stable, non-restructuring surface SEM-image of CPP with micro structures produced by hot embossing ydrophilic polyolefin sustainable (no interaction) super-polar, anti-fogging stretchable chemically resistant printable, good adhesion weldable ydrophobic polyolefin sustainable (no fluorine) super-hydrophobic stretchable water repellent, easy-to-clean chemically resistant weldable à Functionalization of packaging surfaces

11 Functionalization: Tailoring the wettability WCA = 146 without nano with nano WCA = 6

12 Additional functionality: Wettability of CPP v Anti-fogging effect v Easy-to-clean surfaces v Complete emptying of content Untreated CPP: 97 Structured/coated CPP: 6 Anti-fogging effect Structured/coated CPP: 146 Water repellence

13 Additional functionality of polypropylene wettable - anti-fogging weldable - sealable printable, ready to be coated ref. ref. ref. incoat incoat incoat RT 4 C 80 C printed, incoat plasmatreated CPP film (75 µm) removed tape

DLC with metallic contacts : Corrosion protection Sustainable Nano Texturing of DLC Layers: Ø Durable encapsulation of metallic nano contacts Ø Tailoring of wettability Ø

14 DLC with metallic contacts : Corrosion protection Sustainable Nano Texturing of DLC Layers: Ø Durable encapsulation of metallic nano contacts Ø Tailoring of wettability Ø Substitution of varnish in metallic cans & containers Ø Replacement of varnish on metallic lids 10 of 11 Alu cans: Bisphenol A DLC matrix of 70 nm: Diamond Like Carbon layer

15 DLC thin film and active corrosion protection Micro defect Adjustable wettability Plasma layer: 50 nm Metallic nano contacts (< 10 mg/m 2 ) Anodic corrosion protection Reaction: 2 Me + O 2 à 2 MeO Metallic nano contacts: Æ 5 nm in DLC permanently immobilised DLC: Diamond Like Carbon layer (50 nm): ighly cross-linked Packed. plasma The polymer 6 th Global as durable Summit, matrix June Amsterdam Metallic substrate: Aluminium, steel,.

11/1976 - Determination of electrochemical parameters (impedance-spectroscopy) - Salt spray test (DIN EN ISO 9227 NSS): Storage for 3

16 Excellent corrosion protection by nano contacts Pure DLC layer deposited onto Alfoil with poor protection; pores Metal-doped DLC layer onto Al-foil with good protection; without pores Corrosion tests performed at EMPA: - Pore test according to Verpackungsrundschau 11/ Determination of electrochemical parameters (impedance-spectroscopy) - Salt spray test (DIN EN ISO 9227 NSS): Storage for 3 days at 35 C - Condensed water test climate (DIN EN ISO AT: 7 days with 2 cycles at 100% rel. humidity (8 h at 40 C and 16 h at 23 C)

Excellent corrosion protection by nano contacts Al-foils after 27 days condensed water test: left: ydrophobic, metal-doped DLC right: Chemically cleaned Al-foil, without coating Corrosion tests

17 Excellent corrosion protection by nano contacts Al-foils after 27 days condensed water test: left: ydrophobic, metal-doped DLC right: Chemically cleaned Al-foil, without coating Corrosion tests performed at EMPA: - Pore test according to Verpackungsrundschau 11/ Determination of electrochemical parameters (impedance-spectroscopy) - Salt spray test (DIN EN ISO 9227 NSS): Storage for 3 days at 35 C - Condensed water test climate (DIN EN ISO AT: 7 days with 2 cycles at 100% rel. humidity (8 h at 40 C and 16 h at 23 C)

Protection against corrosion, chemical attacks, and

partly peeled off after 27 days in 50 % Ac Good DLC

acetic acid Ø Ø Optimised coatings could not be

acid Excellent adhesion at dry and wet conditions :

18 Protection against corrosion, chemical attacks, and abrasion for metallic packaging Poor DLC on Al, partly peeled off after 27 days in 50 % Ac Good DLC on Al, without delamination after 27 days in 50 % acetic acid Ø Ø Optimised coatings could not be attacked by aggressive acid solutions such as acetic acid Excellent adhesion at dry and wet conditions : 5B (Cross hatch/scotch test, ASTM D Test B and bending tests)

Benefits of photo-induced titania layers (TiO 2 *) biocompatibility bioactivity detoxification disinfection UV-protection decontamination selective diffusion

19 Benefits of photo-induced titania layers (TiO 2 *) biocompatibility bioactivity detoxification disinfection UV-protection decontamination selective diffusion barrier active self-cleaning anti-fogging RTEM image of a titania* thin film PVD ref. with a thickness of 192 nm: Crystalline domains of anatase [110] in a amorphous matrix

Photocatalytically active titania layers

05 mmol methylene blue solution Activation

titania under visible light at 625 nm *CIF

20 Photocatalytically active titania layers (TiO 2 *) Titania coated surfaces: Fingerprints disappear Activation of titania layers at 365 nm* Bleaching of a 0.05 mmol methylene blue solution Activation of titania layers at 428 nm Activation of titania under visible light at 625 nm *CIF = 1.0 corresponds to bleaching of 1.7 mmol/m 2 d of methylene blue by a PVD-TiO 2 ref. layer (50 nm, on a glass slide) according to ISO 10678:2010

21 Photocatalytic reactions at titania* surfaces O 2 - CB e - O 2 Reactions Redox potential Photocatalyst reaction TiO 2 à electron + hole 3.2 ev VB h + O* O 2 2 O CO 2 C x Organic compound 2 O + Mineral acid O 2- Ti 4+ TiO 2 * (anatase) hn ³ E g Titania TiO 2 *

Improvement of Photocatalytic Activity by Doping 500 nm Monolayers of noble metal clusters à Increase of activity > 30% 0 0 nm 500 AFM-image of an atomic layer of Ag-clusters with Ø of 10-20 nm

22 Improvement of Photocatalytic Activity by Doping 500 nm Monolayers of noble metal clusters à Increase of activity > 30% 0 0 nm 500 AFM-image of an atomic layer of Ag-clusters with Ø of nm Doping of TiO 2 * with nitrogen, etc. à Variation of E g and increase of activity Doping with metal cations or non-metallic elements Large surface area, open surface morphology Particle size: nanometer-size range (optimum size around 10 nm)

23 Functional properties of titania* layers TiO 2 Layer/glass Sample no. Thickness [nm] Roughness [nm] 633 [nm] E gap [ev] Wettability in dark Activity ISO [µmol/m 2 h] 365 nm 428 nm Stearic acide nm Stearic acide nm PVD TiO 2 ref TiO 2 a IC TiO 2 b IB TiO 2 c IB TiO 2 black IB PE-MOCVD TiO MA TiO 2 a MA TiO 2 b MA TiO 2 c MA TiO 2 ATMO Pilkington ~ Improvement of photocatalytic activity by doping and co-doping the titania layers* PVD TiO 2 layers are more efficient in destroying stearic acid than PE-MOCVD TiO 2 layers *Catalytic Improvement Factor CIF: Comparison to the internal reference layer PVD TiO 2 ref. (50 nm, on a glass slide) for bleaching of 1.7 mmol/m 2 d aqueous solution of methylene blue 1 LED white light (LEDON 10 W, 2700 K, 600 lumen, 625 nm, distance 5 cm): CIF = 6.8 *Eva Maria Moser et al., Surface & Coatings Technology 227 (2013) 2-9

24 Destruction of stearic acid: Fingerprints & germs 25 Concentration of stearic acid [mol 10-3 ] Time of irradiation 365 nm] PVD-b 1000 nm PVD-b 200 nm PVD 1000 nm PVD 200 nm PECVD-c 130 nm Roughness [nm]: h 1 h 1 h AFM-Images: ~ 200 nm thick PVD-TiO 2

Germ-inhibiting features of titania* Antibacterial activity under visible light PVD TiO 2 -b 13.8.3.0047-1 (300 nm, CIF = 7.0/1.7 RMS = 5.2 nm, hydrophilic) PE-MOCVD TiO 2 -c 13.8.3.0047-2 (200 nm, CIF = 7.

25 Germ-inhibiting features of titania* Antibacterial activity under visible light PVD TiO 2 -b (300 nm, CIF = 7.0/1.7 RMS = 5.2 nm, hydrophilic) PE-MOCVD TiO 2 -c (200 nm, CIF = 7.3/3.1 RMS = 1.0 nm, hydrophobic) PVD TiO 2 black (1.4 µm, CIF = 10.1/1.3 RMS = 5.0 nm, hydrophilic) Tests according to ISO 22196: Growth reduction efficacy [log cfu] E. coli: 0.75 (slight) S. aureus: 0.62 (slight) E.coli: 2.35 (significant) S. aureus: 2.46 (significant) E. coli do not stick well to the titania surface and can be removed easily E. coli: > 5.52 (strong) à 20 of 1 mio germs S. aureus: > 3.68 (strong) *Tests were performed according to ISO 22196: Sterilisation if <1 of 1 mio germs after 24 hours no illumination illumination for 1 day illumination for 6 days AFM images of E. coli on the TiO 2 surface: Kayano Sunada et al., Journal of Photochemistry and Photobiology A: Chemistry 156 (2003)

26 Combination of structuring and plasma layers Active*, interacting surfaces Passive, not interacting surfaces TiO 2* and micro structure super-hydrophobic Θ >120 surface with very weak polarity DLC phob flat or with micro structure TiO 2* flat or with micro structure hydrophobic < Θ <120 surface with weak polarity DLC and polymers (-C-, Si-C-, F-Si-,) TiO 2* smooth or nano structure hydrophilic < Θ <80 surface with high polarity DLC phil, SiO x, TiO x (-C-O, -CO, -NO x ) TiO 2* smooth or nano structure super-hydrophilic Θ < 10 surface with very high polarity DLC phil, SiO x, TiO x (-C-O, -CO, -NO x ) The surfaces easy-to-clean are distinguished by their surface energies and the micro-nano structures of the surfaces. (Θ = water contact angle)

27 Summary wettability DLC phob and TiO 2 * structuring multi functionality clusters advanced barriers

28 Thank you! The human tendency to regard little things as important has produced very many great things. Georg Christoph Lichtenberg ( ) R&D projects No , , PFNM-NM have been funded by CTI Several patents are hold for all presented thin films and deposition processes. Prof. incoat Gmb C-8212 Neuhausen am Rheinfall

TiO 2 particles - Fundamentals and Applications as photocatalyst

TiO 2 particles - Fundamentals and Applications as photocatalyst Most information taken from TiO2 photocatalysis Fundamentals and Applications by Akira Fujishima, Dr. Kazuhito Hashimoto, and Dr. Toshiya