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Institute of Mechanical Process Engineering and Mineral Processing
Nanoparticles in OrganicSolvents with Polymers
Stability and Consequences Upon MaterialSynthesis Through Spray Drying
Martin Rudolph, Urs A. Peuker
1
German Research Foundationproject: PE1160/7-1
*
June 29th 2011NanoFormulation 2011
Outline
1) Motivation
2) Solution Method
3) Preliminary Investigations
4) Theory of Nanoparticle Interactions
5) Experiments - Stabilitya) Destabilization with non-adsorbing PMMA, PC, PSb) Stabilization with adsorbing PVB
6) Summary and Conclusion
June 29th 2011NanoFormulation 2011
3
1 Motivation
[email protected] 29th 2011NanoFormulation 2011
• Synthesis of highly filledpolymer nanoparticle composites ( Nano > 10 %)
Magnetic Beads forsorptive Bioseparation
Hickstein, B., Peuker, U.A.J Appl Poly Sci, 112, 2366
4
1 Motivation
[email protected] 29th 2011NanoFormulation 2011
• Synthesis of highly filledpolymer nanoparticle composites ( Nano > 10 %)
Composite Micropowderfor Micro Injection
Molding
5
1 Motivation
[email protected] 29th 2011NanoFormulation 2011
• Synthesis of highly filledpolymer nanoparticle composites ( Nano > 10 %)
• Overcoming problem ofdispersing(deagglomeration + mixing)
6
1 Motivation
[email protected] 29th 2011NanoFormulation 2011
• Synthesis of highly filledpolymer nanoparticle composites ( Nano > 10 %)
• Overcoming problem ofdispersing(deagglomeration + mixing)
• We present an alternative modular process with thesolution and spray dryingmethod
Outline
1) Motivation
2) Solution Method
3) Preliminary Investigations
4) Theory of Nanoparticle Interactions
5) Experiments - Stabilitya) Destabilization with non-adsorbing PMMA, PC, PSb) Stabilization with adsorbing PVB
6) Summary and Conclusion
June 29th 2011NanoFormulation 2011
[email protected] 29th 2011NanoFormulation 2011
• Polymers• Poly(methyl methacrylate)• Poly(vinyl butyral)• Poly(bisphenol A carbonate)
• Nanoparticles• Fe3O4 magnetite,
superparamagnetic
• Solvent(s)• Dichloromethane• Ethyl Acetate
• Surfactants• carboxylic acids (C14 - C18)
PVBPMMA
PC
15 n
m
2 Solution Method
Outline
1) Motivation
2) Solution Method
3) Preliminary Investigations
4) Theory of Nanoparticle Interactions
5) Experiments - Stabilitya) Destabilization with non-adsorbing PMMA, PC, PSb) Stabilization with adsorbing PVB
6) Summary and Conclusion
June 29th 2011NanoFormulation 2011
11
3 Preliminary Investigations
Investigations with TEM and pc-AFM
June 29th 2011NanoFormulation 2011
• TEM good distribution for spray driedmicrocomposite particle
TEM, spray dried particle
PMMA49 RS21 MAG30
12
3 Preliminary Investigations
Investigations with TEM and pc-AFM
June 29th 2011NanoFormulation 2011
• TEM good distribution for spray driedmicrocomposite particle
• phase contrast AFMshows good distribution in an injection moulded sample
• BUT: both investigations onlyhave a very narrow field of view
phase contrast AFM,injection moulded sample
PMMA64 RS06 MAG30
Rudolph,M. Chem Ing Tech, 82, 2189 (2010)
13
3 Preliminary Investigations
Investigations with TEM and pc-AFM
June 29th 2011NanoFormulation 2011
• phase contrast AFMlarge areas of higher phasevalues
phase contrast AFM,injection moulded sample
PMMA64 RS06 MAG30
14
3 Preliminary Investigations
Investigations broad field pc-AFM and BSE-SEM
June 29th 2011NanoFormulation 2011
• phase contrast AFMlarge areas of higher phasevalues
• similar „clusters“ for BSE-SEM
back scattering electronSEM, sample as before
PMMA64 RS06 MAG30
15
3 Preliminary Investigations
Agglomerates? / Primary Particles?
June 29th 2011NanoFormulation 2011
16
3 Preliminary Investigations
PMMA61 – RS09 – MAG30PMMA61 – RS09 – MAG30 PMMA40 – RS10 – MAG50PMMA40 – RS10 – MAG50June 29th 2011NanoFormulation 2011
Investigations broad field pc-AFM and BSE-SEM
17
3 Preliminary Investigations
PMMA61 – RS09 – MAG30PMMA61 – RS09 – MAG30 PMMA40 – RS10 – MAG50PMMA40 – RS10 – MAG50
Where are they from?Where are they from?
June 29th 2011NanoFormulation 2011
Outline
1) Motivation
2) Solution Method
3) Preliminary Investigations
4) Theory of Nanoparticle Interactions
5) Experiments - Stabilitya) Destabilization with non-adsorbing PMMA, PC, PSb) Stabilization with adsorbing PVB
6) Summary and Conclusion
June 29th 2011NanoFormulation 2011
• strong VAN DER WAALS attractionleads to agglomeration
• stabilization against agglo-meration with surfactants byliquid-liquid phase-transfer
chemisorption andphysic-chemical deaggregation
June 29th 2011NanoFormulation 2011
surfactant of choice: ricinoleic acid
Machunsky, S. Coll & Surf A, 348, 186 (2009)
Gyergyek, S. J Coll Interf Sci, 354, 498 (2011)
4 Theory of Nanoparticle Interactions
• strong VAN DER WAALS attractionleads to agglomeration
• stabilization against agglo-meration with surfactants byliquid-liquid phase-transfer
June 29th 2011NanoFormulation 2011
4 Theory of Nanoparticle Interactions
2
2
22H
AttractionvdW 24ln
22
42
6 hhh
hhhCE
12
,0
12
,21
1ln222FattyAcid
2
Repulsion entroprh
rhrhh
rrhTkA
rE
rHh
BornRepulsion entropAttractionvdW ninteractio EEEE
H 2r
Rosensweig,R.E. A.I.Ch.E.Symp.Ser., 5, 104 (1965)June 29th 2011NanoFormulation 2011
4 Theory of Nanoparticle Interactions
[email protected] 29th 2011NanoFormulation 2011
4 Theory of Nanoparticle Interactions
[email protected] 29th 2011NanoFormulation 2011
4 Theory of Nanoparticle Interactions
[email protected] 29th 2011NanoFormulation 2011
4 Theory of Nanoparticle Interactions
• strong VAN DER WAALS attractionleads to agglomeration
• stabilization against agglo-meration with surfactants byliquid-liquid phase-transfer
• stability effects by polymeraddition
non-
adso
rbin
gad
sorb
ing
stabilizing destabilizing
June 29th 2011NanoFormulation 2011
4 Theory of Nanoparticle Interactions
Depletion interaction – Phase diagrams
Ilett,S.M. PhysRevE, 51, 1344 (1995)June 29th 2011NanoFormulation 2011
4 Theory of Nanoparticle Interactions
Outline
1) Motivation
2) Solution Method
3) Preliminary Investigations
4) Theory of Nanoparticle Interactions
5) Experiments - Stabilitya) Destabilization with non-adsorbing PMMA, PC, PSb) Stabilization with adsorbing PVB
6) Summary and Conclusion
June 29th 2011NanoFormulation 2011
29
5 Experiments – stability
• assessment of the massconcentration of primaryparticles wprimary
• centrifugation and determi-nation of the concentration withTGA, Photospectrometer
centrifugationxprimary, supernatant < 40 nm
diluted supernatant after centrifugation,
increasing cPoly
Rudolph,M. J Coll Interf Sci, 357, 292 (2011)June 29th 2011NanoFormulation 2011
Outline
1) Motivation
2) Solution Method
3) Preliminary Investigations
4) Theory of Nanoparticle Interactions
5) Experiments - Stabilitya) Destabilization with non-adsorbing PMMA, PC, PSb) Stabilization with adsorbing PVB
6) Summary and Conclusion
June 29th 2011NanoFormulation 2011
31
5a Destabilization with non-adsorbing polymers
MM
AP
C
destabilization: decreasing primaryparticle concentration with increasingpolymer concentrationJune 29th 2011NanoFormulation 2011
F in %80 70 60 50 40 30
cMag = 24.4 g/l
32
5a Destabilization with non-adsorbing polymers
MM
A
kinetics of coagulation: not rapid fast drying after mixing should reducelarge amount of agglomerates
Prim
ary
Par
ticle
s
Agg
lom
erat
es
June 29th 2011NanoFormulation 2011
kinetics measuredwith DLS
Sympatec Nanophox
cMag = 1.2g/lcPoly = 58.9 g/l
33
5a Destabilization with non-adsorbing polymers
MM
A
kinetics of coagulation: problem ofcomparability to stability investigationdue to very low colloid concentrationJune 29th 2011NanoFormulation 2011
kinetics measuredwith UVVISat 600nm
cMag = 1.2g/lcPoly = 58.9 g/l
34
5a Destabilization with non-adsorbing polymers
[email protected] 29th 2011NanoFormulation 2011
• Nano-Fe3O4 dispersionunder microscope withcMag = 1.5 g/l
• addition of PMMA leadsto larger light-opticallyvisible agglomerates,
= 15 min
35
5a Destabilization with non-adsorbing polymers
[email protected] 29th 2011NanoFormulation 2011
• Nano-Fe3O4 dispersionunder microscope withcMag = 1.5 g/l
• addition of PMMA leadsto larger light-opticallyvisible agglomerates
• inverted BSE-SEM ofspray dried particlesPMMA64-RS06-MAG30show agglomerates aswell
36
5a Destabilization with non-adsorbing polymers
[email protected] 29th 2011NanoFormulation 2011
• similar agglomeratesizes for dispersion andmoulded BSE-SEM crossection
Outline
1) Motivation
2) Solution Method
3) Preliminary Investigations
4) Theory of Nanoparticle Interactions
5) Experiments - Stabilitya) Destabilization with non-adsorbing PMMA, PC, PSb) Stabilization with adsorbing PVB
6) Summary and Conclusion
June 29th 2011NanoFormulation 2011
38
5b Stabilization with adsorbing polymer
VB
stabilization: increasing primary particleconcentration with increasing polymer concentration
PVB
PMMA, PC
cPoly
PMMA
PC
June 29th 2011NanoFormulation 2011
F in %80 70 60 50 40 30
39
5b Stabilization with adsorbing polymer
VB
particle size: increase in particle sizewith adsorbing polymer layer forming, of Langmuir type (line)
PVB
PMMA, PC
cPoly
June 29th 2011NanoFormulation 2011
F in %80 70 60 50 40 30
40
5b Stabilization with adsorbing polymer
VB
adsorption isotherm: Langmuir type adsorption of PVB on sterically stabilized nanomagnetite
PVB
PMMA, PC
cPoly
04.0/497.0
,1
PVBmax,
Poly
PolyPVBmax,
kggck
ck
June 29th 2011NanoFormulation 2011
F in %80 70 60 50 40 30
Outline
1) Motivation
2) Solution Method
3) Preliminary Investigations
4) Theory of Nanoparticle Interactions
5) Experiments - Stabilitya) Destabilization with non-adsorbing PMMA, PC, PSb) Stabilization with adsorbing PVB
6) Summary and Conclusion
June 29th 2011NanoFormulation 2011
42
Solution and spray drying process issuitable for nanocomposite synthesis
HOWEVER: nanoparticle interactionshave to be considered
Added, solved polymers will influencenanoparticle interaction
Stabilization through adsorbingpolymers reveals suitability of thesolution method
6 Summary and Conclusion
PV
BP
CP
MM
AJune 29th 2011NanoFormulation 2011
Institute of Mechanical Process Engineering and Mineral Processing
43
Thanks for yourinterest!
Sponsored by theGerman Research Foundation:
DFG (PE1160/7-1)
Martin Rudolph
June 29th 2011NanoFormulation 2011
Meet me at poster D-PO3-20» Nanofix – Nanoparticle-wax-formulationsas Additives for Extruder Compounding«
44
Supplemental
Filler Homogeneity – SEM Analysis (F = 30 %)
cov(A) = 0.98
cov(A) = 5.45
Com
poun
ding
Solu
tion/
Dry
ing
B-SEMcross section Binary Voronoi
coefficient ofvariance - cov
June 29th 2011NanoFormulation 2011
45
Supplemental
PMMA61 – RS09 – MAG30PMMA61 – RS09 – MAG30
PMMA49 – RS21 – MAG30PMMA49 – RS21 – MAG30
Phase contrast AFM analysis
Rudolph,M. CIT, 82, 2189 (2010)June 29th 2011NanoFormulation 2011
47
Supplemental
[email protected] 29th 2011NanoFormulation 2011
D – surfactant (detergent) ratio
F – filler concentration
• Composition
nano
surfactant
mmD
polymersurfactantnano
nano
mmmmF
1
1
surfactant
polymer
1
nano
polymer
polymer
111
111
DDF
DF
Poly – polymer concentration
48
Supplemental
[email protected] 29th 2011NanoFormulation 2011
• Interparticle Distance
1
surfactant
polymer
nano
polymernano
3
nano
111
1433
DF
xID
51
Supplemental
[email protected] 29th 2011NanoFormulation 2011
• Gravimetric Characterisation with TGA/FTIR
over
all
cent
rifug
ed
overallMag,w
centriMag,wxStokes = (20 ± 2) nm
characteristic mass-loss
52
Supplemental
[email protected] 29th 2011NanoFormulation 2011
• Segregation Effects with Spray Drying
fraction x50,3 wMagm(600°C-800°C) /
wMagyield
cylinder 8 µm 47.1 % 15.8 % 29.2 %cyclone 5 µm 44.5 % 15.9 % 60.5 %
filter 3 µm 21.5 % 18.7 % 10.3 %
TGA PSDcylinder cyclone filter
53
Supplemental
• Spray Drying
• Büchi lab scale spray dryerco-current, inert-loop
• x50, composite 4 µm
• up to 100g/h composites
low highviscosity/concentration
June 29th 2011NanoFormulation 2011