© Fraunhofer IGB

Dr. Achim Weber

Functional Core-Shell Micro- and Nanoparticles for Technical Applications

Workshop: Anti-corrosion methods and condition monitoring for the oil and gas industry,IPT, São Paulo, Brazil, 22nd March 2011

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Functional surfaces due to filled particlesCorrosion inhibitors, nanocapsulesGalvanic coating

Plasma treatment of surfacesTechnology overviewDifferent geometries and coatingsAnti corrosion coating

3D Laser printingClick chemistryAdjustable glass transition temperature, biocompatibility

Overview

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• Innovation in surface modification

• Multidisciplinary development

• Combination betweenelectrochemical methods andorganic capsules

Functional surfaces with liquid filled capsules

C. B. Santos, M. Metzner, C. Mayer 2011

“Modificação das propriedades superficiais dos materiais através da integração de cápsulas em uma matrix metálica”

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A functionalization of a metallic surface is achieved by the integration of nanocapsules into the matrix of a metallic coating. The capsules are meant to be electrodeposited together with the metal, forming a functional composite coating.

Conventional AFM (left) and AFM phase image (right) of nanocapsules in a functionalized metallic coating. The black dots represent the soft mechanic response of the polymer capsules in the metallic coating layer.

C. B. Santos, M. Metzner, C. Mayer 2011

Functional surfaces with liquid filled capsules

•Matriz metálica + cápsulas preenchidas com líquido = formação da camada metal/cápsules.

• Falha na camada leva a liberação do líquido (lubrificante, inibidor de corrosão,etc.) que fornece protreção local.

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C. B. Santos, M. Metzner, C. Mayer 2011

Functional surfaces with liquid filled capsulesActive agents (filling)

Exemplo de agentes ativos

• Inibidores de corrosão• Lubrificantes• Medicamentos• Pigmentos e combinações de diferentes agentes ativos

Examples of active agents

• Corrosion inhibitors• Lubricant• Drugs• Pigments• Combination

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Punctual mechanic load on the surface destroys some of the capsules, leading to a limited local release of the liquid content and initiating its desired function which may consist in a temporary anti-corrosive protection or in local lubrication of the surface.

SEM Micrograph from wear track after wear test with linear displacement against ceramic ballC. B. Santos, M. Metzner, C. Mayer 2011

Functional surfaces with liquid filled capsules

• Desgaste da superfície metálica

• Efeito lubrificante do óleo contido nas cápsules, quando metal é desgastado.

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Example:

• Metallic matrix (Zn, Ni, Cu)

• Capsules suspension(from 20 to 60 mL L-1)

• Deposition temp.(max. 50°C)

• pH (from 2 to 11) SEM Microscopy (cross section) of the metallic matrix a) with and b) without

capsules C. B. Santos, M. Metzner, C. Mayer 2011

Functional surfaces with liquid filled capsules:Electrodeposition

a

b

Exemplos:

Matriz metálica (Zn, Ni, CU)

Suspensão com cápsules no eletólito (de 20 a 60 mL*L-1)

Temperatura de deposição(max. 50°C)

Valor de pH do eletrólito(entre 2 e 11)

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Wear tests on samples without and with capsules. The friction coefficient (µ) decreases with the addition of capsules in the coating. The capsules showed a lubricant effect in the metallic matrix.

Functional surfaces with liquid filled capsules:Wear tests

C. B. Santos, M. Metzner, C. Mayer 2011

Matrix

Matrix + Capsule

Nr. Sliding

Efeito lubrificante: a redução do coeficiente de atrito indica melhora na lubrificação do material devido a presença de cápsules preenchidas com óleo.

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Functional surfaces due to filled particlesCorrosion inhibitors, nanocapsulesGalvanic coating

Plasma treatment of surfacesTechnology overviewDifferent geometries and coatingsAnti corrosion coating

3D Laser printingClick chemistryAdjustable glass transition temperature, biocompatibility

Overview

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Electrode

Electrode

Low pressure plasma: Principle

Vacuum-chamber

Pump

Gas inlet

match

r f z.B. 13,56 MHz

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Plasma reactors: Examples

area 660 cm2

variable electrode distance heatable electrode

area 1165 cm2

plasma treatment of big samples (up to DIN A3)e.g. textiles …

ProjektpartnerPink Plasma finish

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Up and down scaling

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Plasma for internal coating

HoseHose BottlesBottles

- barrier- residual draining

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Easy-to-clean and anti-swelling coatings:Parylen layers

coated

withoutcoating

Prevention of swellingSolvent resistence

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Plasma for protective coatings: Corrosion, fouling, icing

plasma polymerization

Hexamethyldisiloxane (HMDSO) C6H18Si2O

Trifluormethane CHF3

Hexaflouropropylene C3F6

or c-C4F8

hydrophilic (glass-like, protective SiOx coating)

hydrophobic(preservation of the methylene groups)

hydrophilic + oleophobic

(application: e.g. anti-icing surfaces on foils for aircraft and wind turbines)

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Metalized polyester with and without plasma coating

Corrosion Tests

(a) (b)

Optical microscope images of metalized (aluminum coated) polyester nonwoven after corrosion test (water condensation test 98°C 2h). (a) Without coating, corrosion takes place. (b) With plasma coating no corrosion can be recognized.

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Functional surfaces due to filled particlesCorrosion inhibitors, nanocapsulesGalvanic coating

Plasma treatment of surfacesTechnology overviewDifferent geometries and coatingsAnti corrosion coating

3D Laser printingClick chemistryAdjustable glass transition temperature, biocompatibility

Overview

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3D Printing with electrophotography

Layer-by-layer assembly

Printing unit Fusing unit

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Polymer particle

Ø ≈ 1-30 µm

Additives

(e.g. dye pigments)

Coating(Silica nanoparticles)

10 - 100 nm

zeon.co.jp

Toner components

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Bulk polymer

Extrusion and grinding

Air jet milling

Toner manufacturing

irregular particles

low resolution (< 300 dpi)

konicaminolta.com

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Chemical particle synthesis

spherical particles

high resolution (≈ 600 dpi)

Heterogeneous polymerization Air drying

Clean up

emt-india.net

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Particle fusion

Thermal curing leads to deformation

(Kumar et al., University of Florida)

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Chemical fusion

stability via covalent bonding (“click-chemistry“)

requires mild conditions to protect functional surfaces

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Chemical fusion

stability via covalent bonding (“click-chemistry“)

requires mild conditions to protect functional surfaces

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Softening temperatures

Methyl methacrylateTg (PMMA) = 379 K

Methyl acrylateTg (PMA) = 290 K

+

Agglomeration at thermal initiation(AIBN, 60 °C, 24 h)

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Photopolymerization

UV-reactors (4 units)

Volume: 50 mLPolymer content: 5 g

UV-lamp

Volume: 1000 mLPolymer content: 100 g

Temperature: 278 KPolymerization time: 24 h

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Protective colloids

Silica HDK N20®

3 µm

6 µm

PVA (13% PVAc)

PVP K30®

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Protective colloids

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Polymer functionalization

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Outlook

Model system for the electrophotographic rapid manufacturing process: Branched tube with bulk and surface made from different materials (bulk, interface, and support material)

Building up tubes

Fixation of un-combinable materials

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Conclusion

Liquid filled capsules for an anti-corrosion coating

Plasma treatment for adjustable surface modifications: Protective coatings

Different geometries for plasma coating available

3D electro photography: Conceivable via functionalized toner particles

Particle manufacturing: Chemical synthesis favorable for high resolution printing & successful suspension polymerization via UV-initiation

Particle modifications: Simple hydrolysis under basic conditions

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Your partner from Fraunhofer IGB

Dr. Achim WeberGroup manager„Particle-based Systems and Formulations “Telefon +49 711 970-4022achim.weber@igb.fraunhofer.de