Advances in Nano-Coatings to Achieve Interesting Nano-Effects

Transcription

1 Nano-Technologies VSchmidHannovermesseSurfaceTechnology15.Ppt, 1 Advances in Nano-Coatings to Achieve Interesting Nano-Effects Hannover Messe Surface Technology Deutsche Messe AG, Messegelände, Hannover Phone: , Mail: incoming@messe.de Dipl.-Chem. Helmut Schmid Fraunhofer-Institute Chemical Technology (ICT), Box 1240, D Pfinztal, Germany Web: Phone: , Mail: sd@ict.fhg.de

2 Multi-Functional Nano-Coatings 2 Index 1. Introduction / Motivation 3 2. Nature and Principles of the Effects 7 3. Cooperation within the Consortium Sample Examples / Final Applications Summary / Conclusion Outlook 33

3 Introduction / Motivation 3 Why nano effects as wire coatings for architectural applications? The topic of "nanotechnology" has caused high expectations in public perception that were not always met. Therefore, it is interesting to clarify the question what can be realized by relatively simple means of chemical nanotechnology: -Create interesting optical effects -Achieve functional effects -Unique features for partner companies -The competitiveness is improved -Basics for perspective product applications -Companies will be stabilized and thus developed -Securing the future of jobs

4 Nanotechnology 4 Sources: Fotocommunity, Pons, Wikipedia Natural NT Artifical Nanotechnology Physical Chemical Inorganic Nanoparticles Organic Nanoparticles Sol/Gel-Technology (CNT s) Polymer-Binder Nano-Products Release-Systems Non-Release-Syst.

5 Classification, our Understanding of Nanotechnology 5 Atomar, Molecular Chemistry Nano Dimension Macroscopic Dimension Oligomers, Polymers Crystallites Atoms, Molecules DNA Proteins Viruses Bacteria Biolog. Cells VIS Human Hair 0,1 nm 1 nm 10 nm 100 nm 0,1 μm 1 μm 1000 nm 0,01 mm 10 μ Figure 5.1 Size classification of well known objects. Interesting Nano-Region: 5 50 nm.

6 Classification, how you can imagine the dimension of 1 nm 6 Sources: Wikipedia Figure 6.1 If the gull lands on the aircraft carrier he will delve deeper by 1 nm (assuming a theoretically smooth sea).

7 2 Nature and Principles of the Effects Optical Principles of Pigments 7 Source: Pfaff Transparent Effect-Pigments: Reflection, Refraction + Interference, partially Absorption Metallic Effect-Pigments: Reflection Roofing Effect: f (Density, Viscosity) Absorption Pigments: Absorption, Scattering (Diffuse Reflection)

8 Effect 1: Viewing angle-dependent color impression through nano-coating of micro-interference pigments 8 Source: Pfaff Figure 8.1: Dependence of the interference color based on the layer thickness. This per se known effect is improved, expanded and polymer-chemically integrated, so that a functional coating results, which also has the required environmental resistance.

9 Viewing angle-dependent color impression through nanocoating of micro-interference pigments 9 Source: Pfaff Figure 8.1: Schematic representation of the effect of material and layer combinations in order to exploit the color space.

10 Pigment-Analysis 10 Figure 10.1 SEM-Record of Interference-Pigments NPI

11 Pigment-Analysis 11 Figure 11.1 SEM-Record of Interference-Pigments NPI Dimension of Nano-Coating: nm.

12 Pigment-Analysis 12 Figure 12.1 Polarization-Micrograph of Interference- Pigments NPI00401-(Übersicht2Polarisation).

13 Theoretical Aspects of Nano-Stabilization 13 Source: Penth Thermodynamic Effect Desired Free Energy Kinetic Aspect r (Nano-Formation) >> r (Growth, Agglomeration) Necessity for Stabilization -> Surface Treatment

14 Theorectical Aspects Potential and Field-Theory (cosh cos ) U (cosh cos ) U sinh *(cos cos ) U U (, ) * * * B B B 2 (cosh cos ) 1 U (cosh cos )*sin * * sinh( U(, )) (1) 2 tan B U: Reduced Electrostatic Potential, B: Constant in Bispheric System of Coordinates Equation 1 Calculation of Surface Potential U according to Poisson- Boltzmann-Equation (1) in order to make a suitable selection of chemical additives enabling stabilization and preventing from reagglomeration. B correlates with k H (Hamaker Constant) of Van der Waals Interaction. This type of interaction has to be reduced.

15 Theorectical Aspects Potential and Field-Theory 15 Source: TU-Darmstadt Figure 15.1: Theory of Nano-Particle-Stabilization: FE-Calculation of Electrostatic-potential-gradient between two Al 2 O 3 -Particles (5 nm) as a Function of ph and Electrolyteconcentration (left ph2, 0.1 M NaCl, right ph4, M NaCl)

16 Effect 2: Plasmon-Luminescence-Lightingeffect 16 Source: Aldrich Figure 10.1: The plasmon effect is expected from nanotechnology. In metallic nanoparticles (shown above by the example of nanosilver) light excitation (in the sense of electromagnetic radiation) of the free metallic conduction electrons causes collective resonant oscillations of these "charge clouds". These surface plasmons leads to a lighting effect, if the resonant frequency is in the visible range of the electromagnetic spectrum. The resonance frequency is adjustable via the size of the nanoparticles.

17 Effekt 2: Plasmon-Luminescence-Lightingeffect 17 Source: Mineralienatlas Figure 11.1: Additional use of the luminescence effect. Light activation in the UV / VIS range can lead to three types of excitations: Electronic excitation of valence electrons, rotational and vibrational excitation of molecules. If we restrict to the electronic excitation of valence electrons, the electrons are first lifted from the ground state S 0 to the higher energy levels of S 1 and S 2 (HOMO - LUMO transitions). The relaxation occurs by complex laws with additional consideration of the electron spins. The P-transition (shown above in red) finally leads to radiation emission.

18 Effect 3: Switchable Thermochromic Effect / Change of IR Reflection 18 The Thermochromic Effect is represented by a reversible chemical reaction that leads to a change of the electronic conjugation of double bonds. This effect is performed in a switchable way - as a function of temperature -, where reaction temperature was set to 30 0 C for this specific application. For this function nanoparticles additionally play an important role. When heated, the color of the system changes from black to transparent. This is not only an example, usable as an advertising gag -, since it changes the IR reflection coefficient dramatically, heat balancing layers can be produced in this way.

19 Main Steps from Nano-Particle-Production to Applications 19 Nano-Particle Synthesis Analysis / Characterization Transformation in Liquid Phase System-Integration Polymer-Technology Processing-Technology Technical Applications Medical Applications Stabilization

20 Nano-Analysis, Characterization 20 Morphology: SEM TEM (IKP) Transmission e - M. STM Scanning Tunnel M. X-Ray Fluorescence Analytical Methods Particle Size Distribution: PCS Low Surface Energy of Dispersion-Media improves Wettability. AFM Atomic Force M. AES - ICP Chem. / Structure: X-Ray Diffraction

21 Theoretical Aspects Safety Concept 21 Intra- and intermolecular Bounding Particle-Size Dependency Physisorption Mech. Anchoring Weak Elektrostatic Interakt. Potential-Theory Ionic Chemisorption Van-der-Waals Partial-Charge, Dipole-I., (H-)Bridges: 20 x VdW Kovalent Metallic Transition-State-Theory Surface-Thermodynamics Molecule-Orbital-Theory Crystal-Field-Theory

22 3 Cooperation within the Consortium 22 Project Partner 1: Additiv-Integration Project Partners 2+3: Coating, Application Waterborne System Technology Platforms Organic Binders; 1 C, 2 C Pigments, Effect Substances ICT: Concept, Samples, Analysis

23 4 Sample Examples / Final Applications 23 Figure 14.1: Coating of a wire tape to achieve a viewing angledependent color impression using the nano-coated particles NPI00401.

24 Sample Examples 24 Figure 15.1: Coating of a wire ribbon to achieve a plasmon / luminescence effect using the particle NPI The radiation can be seen in the lower part of the picture.

25 Sample Examples 25 Figure 16.1: Coating of a wire tape to obtain a - as a function of temperature reversible switchable thermochromic effect using the additive NPI The left sample part was heated to 31 0 C and changed the color from black to transparent.

26 Environmental Testing, UV-Tests 26 Figures Results of microscopic evaluation for the nanogold lacquer NFO00101 (4), area B1, 241 h (top), area B2, 193 h (bottom). There are no visible defects.

27 Environmental-Testing: Condensation Water / Climate Change Cycling Tests 27 Sources: Mendl Condensation Water / Climate Change Cycling Tests, Air Temperature Changes according DIN EN 6270 AT Test Conditions Cycle: -8 h including warm up at (40 ± 3) C; rel. H ~ 100 % with condensation at samples -16 h including cool down (closed climate chamber) at (18 28) C; rel. H. ~ 100 % (~ saturated) Number of Cycles: 3 Total Test Duration: 72 h Test Device: Corrosion Chamber Liebisch SKBWF 1000 A-TR Visual Inspection

28 Sample Examples / Final Applications 28 Figure 17.1: Coated sample Nano-Gold at Freeport, Singapore.

29 Final Applications 29 Figure 17.1: Indoor application (left picture) and outdoor use as cladding of a parking garage in Barcelona (right picture) of woven nano-coated metal wires / tapes.

30 Final Applications 30 Figure 17.1: Final applications shown by example of Ticon, Tripoli (Source: GKD). Architectural applications typically comprise large surface areas in the context of major orders. But applications of such coatings must not remain limited to architecture.

31 5 Summary / Conclusion 31 Nanotechnology plays a key role in multifunctional coatings. As a matter of fact the topic "nanotechnology" has caused high expectations in public perception that were not always met. Therefore, it is interesting to clarify the question what can be realized by relatively simple means of chemical nanotechnology. Of particular interest are the following effects with product relevance, which are explained in the presentation: -Viewing angle-dependent color impression through nano-coating of micro-interference pigments -Plasmon-Luminescence-Lighting Effect -Switchable Thermochromic Effect / Change of IR Reflection For product development usually a combination with other technologies, e.g. polymer technology is necessary. To achieve a convincing technical solution all aspects of nano particle production, stabilization, analysis and system integration must be covered.

32 5 Summary / Conclusion 32 From the very beginning, the following aspects need to be considered: -Non-toxicity, environmental compatibility, safety concept and it s analytical review -Economy aspects, production possibility and scale-up -Homologation aspects and legislative injunctions To enable a perspective market introduction the integration of a partner with market access and experience is recommended.

33 6 Outlook 33 Further Nano-Products with additional functionality, will be put to market soon Numerous promising systems are still under development Multi-Functional Nano-Coatings are identified as a promising field of activity Recognizing the overall benefit, investments in this technology makes sense. Fraunhofer-ICT is looking for further cooperations and product applications especially in your country

34 Nano-Technologies 34 Спасибо за ваше внимание! Danke für die Aufmerksamkeit! Dziekuje za uwage! Danko pro via atento! Děkuji za pozornost! Tak for din opmærksomhed! Σας ευχαριστώ για την προσοχή σας! Takk for oppmerksomheten! 非常感谢您的关注 Tack för er uppmärksamhet! ご清聴ありがとうございました Dank u voor uw aandacht! आपक ध य न क ल ए धन यव द דאנק איר פ אר אייער ופמערקז אמקיי ט Terima kasih atas perhatian Anda Tibi gratias ago pro attentio! Obrigado pela vossa atenção! Gracias por su atención! Grazie per l'attenzione! Merci pour votre attention! Thanks for your attention! Cảm ơn bạn đã quan tâm của bạn