coating technology and encapsulation closely connected · coating technology and encapsulation –...

Titel van de presentatie 14-11-2014 10:52

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Coating Technology and Encapsulation – Closely Connected

dr. ir. Nicole Papen-Botterhuis, Scientist

TNO Materials Solutions

Eindhoven

Encapsulation Technologies – Characteristics

High performance materials as well as processing technologies are

required to meet the product demands

Properties:

Size (macro, micro, nano)

Size distribution (monodisperse, polydisperse, bimodal)

Morphology (matrix, core-shell, multicore-shell, double walled, sandwich)

Loading efficiency (maximize active vs. encapsulation material)

Encapsulation efficiency (minimize loss of active material)

Nicole Papen-Botterhuis

TNO Encapsulation Team

barrier

release release

barrier

release Core-shell Matrix Sandwich


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Encapsulation – Why?

Protect ingredients

(against oxygen, water)

Separate components,

prevent interaction



Controlled

release

Adjust

properties

Keep

outside

out

Keep

ingredient

inside

Delayed/slow: Prevent

burst release / premature

leaching (drugs, nutrients

antimicrobials, fertilizers)

Triggered: pH, water,

temperature, enzymes,

pressure/force

Easy & safe handling (solid vs.

liquid, decreased volatility)

Enzyme immobilization

Taste masking

Biocompatibility

Change physical properties

(solubility, structure, density)

Flowability

Hygroscopic control

Microencapsulation can bring you new products, new functionalities,

better product properties, higher added value – if done right

Coating Technology and Encapsulation – Closely Connected?

Encapsulation is in fact the coating of particles at the micro/nanoscale

Different processes/materials

What can we learn from each other?

Capsules can be applied in coatings to obtain an added value or

functional coatings

Isolation

Self-healing

Controlled release of active ingredients such as biocides

Stabilization of pigments

Sometimes added value can also we obtained without capsules, if the

barrier value of the coating itself can be adjusted.




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Development of encapsulation technologies

BASE TECHNOLOGY Year ADDITION Controlled Release

Spray Drying of Solids 1872 Emulsified Oils, 1925,

Special Disk, 1949,1987 Spray Dried Flavors,

Reservoir Structure

Extrusion of Synthetic

Fibers into a bath 1920 Flavor Oils, 1957 Sunkist Process

Fluid Bed Drying Top, Side, Bottom Spray

Nozzle & Partition 1965 Wurster Coating,

Agglomerization

Emulsion polymerization Add Oil to Polymer APS Polytrap

Spun Sugar (Cotton Candy) Emulsify Oil into Hotmelt Fuisz 1991

Droplet Stabilization With

Surfactants Form a Massive Wall Coacervation 1951

Parylene Coating Tumbling of Powder Parylene μE 1983

Polycondensation of Nylon >1930’s Water Medium Interfacial

Polymerization

U/F Resins <1920 Coacervation Formation Polymethyleneurea, U/F

Pan Coating 19th

Century Specialty Coating, e.g.

enteric, “tunnel coating” Enhanced Release,

continuous process



Ronald Versic, RT Dodge Company, USA

Ron Neufeld, Queen’s University, Canada




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Common microencapsulation technologies

Technology Matrix or

Core-shell?

Size

(distribution)

Cost Production

Use

Spray drying large variations

2 - 100 µm

low continuous +++

Spray chilling 20- 200µm low continuous +++

Extrusion > 50 µm low continuous ++

Pan coating >500 µm low batchwise ++

Fluidized bed >50 µm medium batchwise

/continuous

++

Coacervation 1 - 500 µm

high batchwise ++

Interfacial/ in situ

polymerization

1 - 500 µm high batchwise +



LOW

COST

HIGH

COST



Adjusted from www.SWRI.org


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Spray-drying

Widely used in food industry, e.g. to:

convert liquids into powders

protect flavour oils or other ingredients against degradation

Typically aqueous formulations of shell / matrix material

Ingredient either dissolved in matrix or present as emulsion (multi-core)



Advantages:

+ cheap, flexible process

+ continuous process

+ high throughput

+ small particles possible

(Possible) Disadvantages:

− incomplete encapsulation

− mix of particle sizes

New TNO technology: printing-drying

Alternative to spray drying

Droplet generation by inkjet technology



monodisperse

drops

monodisperse

powders

drying

printing

viscosity upto 500 mPa·s

low shear

droplet size ~50 to 120 m

droplet size variation <1%

100 L/h using multiple nozzle head

Advantages:

+ Energy saving

+ Continuous process

+ Monodisperse powders, no fines

+ High density powders


− incomplete encapsulation


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Methods for droplet extrusion

Dropping

Vibration / coaxial air flow (Nisco)

Vibration / electrostatic (Büchi)

Jet cutter (Genialab)

Rotating extruder (SWRI, Sprai, PCT)

Multiple nozzles (Inotech, Brace, TNO)



From R. Neufeld, Queen’s University

Lists are not exhaustive!

Encapsulation by fluidized bed coating

+ Suitable for a wide range of shell materials

+ Tuneable shell thickness

- Only for solid core materials

- Standard not suitable for particles < 50 µm

- Moderate pay-loads, especially for small particles

- Polydisperse products, agglomeration during coating

Typical (food) ingredients: vitamins, minerals, leavening agents

Also used for much larger food components (flakes, grains)

Also used for pharmaceutical & cosmetic applications




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Encapsulation by (complex) coacervation

+ High payloads possible

+ Good core-shell morphology

- Expensive & complex (batch) process

- Limited choice in shell materials

- Polydisperse capsules

Typical ingredients: flavour oils, also fish oil, vitamins etc.

Typical application areas of flavour microcapsules:

chewing gum, toothpaste, baked foods

Release mechanisms: sustained, mechanical or heat trigger



Phase separation of one or more hydrocolloids by changing pH,

salt concentration, etc.

Core-shell particles by co-extrusion



shell liquid

core liquid

piezoelectric

vibrating unit

Concentric nozzle to process core & shell material

Collection in non-solvent or coacervation bath


− no dry powders

− large size (w.o. non-solvent)

− interaction between core & shell

material may occur at the nozzle

Advantages:

+ narrow size distribution

+ high payloads possible

+ good core-shell morphology

Non-solvent stream (optional)


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Core-shell particles by encapsulation printing

New processing technology for microencapsulation:

Generate core droplet by inkjet technology

Encapsulation by a liquid film / curtain of shell material



Example: Encapsulation of oil droplets

mechanical

release

shell = 5 – 8 m

Core: 82 – 86 %

oil droplets

aqueous solution of carrageenan and/or gelatin



gelation

by cooling


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Example: Encapsulation of water-soluble core

aqueous core droplets

(with model dye)

solid microcapsules

with waxy shell

molten

shell material



solidification

by cooling

capsule diameter 70 µm

capsule diameter 400 µm

Size depends on parameters: flow rate, frequency, nozzle diameter

Tuning shell thickness / core-shell ratio

Shell thickness depends on flow rate of liquid film:




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Advantages & challenges encapsulation printer

+ High payloads

+ Continuous process

+ Suitable for wide range of materials (aqueous, oils/waxes, polymers,

solutions, dispersions)

+ High viscosities & temperatures possible

+ Mild process conditions (low T, shear) possible

+ Separate conditions for core & shell materials

+ Well-defined, homogeneous product properties

- No recycling of shell material yet

- Early stage development



fluidized bed

Characteristics of encapsulation processes



1 µm 10 µm 100 µm 1 mm

10%

50%

70%

90%

spray drying

melt

extrusion

complex

coacervation

simple

coacervation concentric

nozzle

Information adapted from: Zuidam et al, Encapsulation Technologies for Active Food Ingredients and Food Processing, 2010

encapsulation

printer

particle diameter

load (%)

30%

matrix type

core-shell

clay Intercalation

spray chilling

… or print-drying

sandwich type


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Application Markets

Pharmaceuticals / Medical/ Animal Healthcare

Food / Nutraceuticals

Feed

Personal Care / Cosmetics

Home Care

Consumer Products

Agriculture / Aquaculture

Building materials / Paints & Coatings

Oil & Gas

Textiles

Energy storage



Skip examples

Pharmaceuticals / Medical / Animal Healthcare

Sustained release (less pills, therapeutic window, from pills to implants)

Targeted release

Taste masking

Enteric release (protection against stomach)

Improved bioavailability

Animal/human cells (islets of Langerhans)



LCTglobal.com


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Encapsulation for Food Innovations

Flavors & Fragrances (aroma)

Immobilization during processing

Edible oils (omega-fatty acids)

Microorganisms (probiotics)

Levening agents

Vitamins

Shelf-life

Taste masking

Enteric release

Bioavailability

Quick dissolving powder

Free-flowing sugar

In situ generation of bactericides



Personal Care/Cosmetics

Controlled release of fragrances: perfume, deodorant

Stabilization / Shelf-life

Bioavailability

Control of odour

Liquid to solid conversion

Cosmeto-textiles

Appearance

Marketing



Pelletech Robert Blondel


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Home care / Consumer goods

Detergents (enzymes)

Adhesives

Controlled release fragrance

Masking odour

Shelf-life

Self-healing

Scratch ‘n sniff

Visual indicators

Liquid crystal displays

Liquid to solid conversion



Agriculture/Aquaculture

Herbicides/pesticides

Handling & Safety

Fertilizers

Pheromones

Plant growth promoting bacteria

Food supplementation

Structuring fish food

Bioavailability

Ingredient stabilization



http://www.google.nl/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&docid=o7vaM6fNxqoZ7M&tbnid=MaQ0UIyZ_jV2WM:&ved=0CAUQjRw&url=http://www.swri.org/4org/d01/microenc/microen/app_ag.htm&ei=BCZDU57jMsnH0QWQwIGABw&psig=AFQjCNHxY-cGMcSXcEjtQclWXNFBVJpK7w&ust=1396995959280985

http://www.google.nl/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&docid=o7vaM6fNxqoZ7M&tbnid=MaQ0UIyZ_jV2WM:&ved=0CAUQjRw&url=http://www.swri.org/4org/d01/microenc/microen/app_ag.htm&ei=BCZDU57jMsnH0QWQwIGABw&psig=AFQjCNHxY-cGMcSXcEjtQclWXNFBVJpK7w&ust=1396995959280985


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Chemical Industry

Lubricants

Adhesives (pressure-sensitive glue)

Enzymes

Inks/pigments

Flavors/Fragrances

Thermochromic dyes

Fermentative production of ethanol, biogas, lactic acid (microorganisms)

Aid in processing: Immobilization, easy to separate

Chemicals for Enhanced Oil Recovery

Phase Change Materials (PCMs) for textiles and energy storage



Building Materials / Paints & Coatings

Controlled release biocide coatings

Pigments

Self-healing coatings

Phase change materials

Antimicrobial coatings

Thermochemical storage




15

Nanoencapsulation

Why?

Optical clarity (drinks, motor oil)

Better surface interactions

Stability of suspensions

Higher penetration depth/uptake (cosmoceuticals, cell therapy)

How? Liposomes, micelles, molecular entrapment, nanoclay

Challenges:

Loading efficiency is a challenge for core-shell particles

Very thin shells needed: ALD, CVD techniques?

Fragility of capsules

Use of large amounts of surfactants for nanoemulsions

Nanopowders not easy to handle (nanotox, flowability)



Conclusions

Encapsulation can provide a solution to enhance products

There are many encapsulation technologies and materials

Encapsulation process should be designed to meet exactly the product

requirements: ask a specialist if you are new in the field

Encapsulation is used in many application areas

Challenges

Better barrier materials/layers

Smaller particles with high loading

Milder encapsulation processes

Biobased encapsulation materials

Overcome regulations

Low-cost solutions




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Smart release of biocides in finishing materials for the sector of construction

The EU project “Axioma”

‘To develop, adapt and apply smart release concepts of eco-acceptable bio-inhibitors to extend service life of

finishing materials substantially.’

Moulds Algae

Axioma why?

14/11/2014 32

• Short bio-resistance of materials leads to early replacement

• Environmental legislation restricts use of biocides and chemicals (Biocidal product directive 98/08/EC) (Biocidal Product Regulation EU 528/2012, 1st Sept 2013)

Nicole Papen-Botterhuis TNO Encapsulation Team


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Modified inorganic particles

1. swelling in a solvent (water)

2. cation exchange (modifier)

3. filtration + drying (de-swelling)

Possibility to load cationic

compounds onto clays, or anionic

compounds onto layered double

hydroxides.

Charge interactions can also take

place with neutral molecules (e.g.

amines).

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+


Change of equilibrium

Eversdijk, J., et al (2012). Development and evaluation of a biocide release system for prolonged antifungal activity in finishing materials. Progress in Organic Coatings, 74(4), 640-644.


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Sample preparation


Rain setup Loaded nanoclay

Coating

Biological and chemical tests

Improvement obtained by biological testing

Results paint



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Results from gypsum

1. free biocide (red)

2. bound biocide with 100 wt% hydrophobic modifier (blue)


Fungal growth

5 times performance improvement

With Clay

Without Clay

Artificial rain tests and Fungal growth tests

Conclusion

Coating Technology and Encapsulation – Closely Connected!



Encapsulation

Coatings capsules

coatings

can be applied to improve the functionality of


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For more information please contact:

Nicole Papen-Botterhuis M.Sc., Ph.D.

TNO

Dept. Materials Solutions

PO Box 6235

5600 HE Eindhoven

The Netherlands

[email protected]

+31 88 866 6234



Groningen

Eindhoven

Den Helder

The Hague

Rijswijk

Delft

Apeldoorn

Leiden

Enschede

Hoofddorp

Utrecht

Soesterberg

Zeist

Helmond

• Independent Dutch nonprofit

research institute

• Approximately 3500 FTE

• TNO Encapsulation team

– 9 FTE core + 20 part-time

– New encapsulation processes

– New encapsulation materials

TNO connects people and knowledge to create

innovations that boost the sustainable competitive

strength of industry and well-being of society

TNO: Netherlands Organisation for Applied Scientific Research

coating technology and encapsulation closely connected · coating technology and encapsulation –...

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