Nanocontainers with controlled Nanocontainers with controlled permeability for feedback active coatingspermeability for feedback active coatings
Contents:
1. Self-healing coatings based on nanocontainers for corrosion protection:
- with pH-triggered release,
- triggered by mechanic rupture,
- with light-triggered release.
2. Polyelectrolyte coatings for corrosion protection:
- inhibitor-free coatings,
- sandwich-like structures with controlled release of the inhibitor.
3. Ultrasonic fabrication of oil- or gas-filled containers:
- gas-filled containers,
- oil-filled carriers.
4. Bioactive coatings based on oil-filled containers.
NanocontainerNanocontainer--based coatingsbased coatings
AdvantagesAdvantagesReduction of negative effect of the inhibitor on Reduction of negative effect of the inhibitor on coatingcoatingPrevention of inhibitor deactivation due to Prevention of inhibitor deactivation due to interaction with coating components interaction with coating components Controllable release of inhibitor on demandControllable release of inhibitor on demandPrevention of the inhibitor leakagePrevention of the inhibitor leakage
To use the nanocontainers loaded with corrosion To use the nanocontainers loaded with corrosion inhibitorsinhibitors
Triggers: pH shift, light, pressure, corrosion products, etc.
Shchukin, D.G., Möhwald, H. (2007): SMALL, 3, 926-943.
Shchukin, D.G., Möhwald, H. (2007): Hollow Micro- and Nanoscale Containers, "Advanced Materials Research" Ed. by L.V. Basbanes. 2007, Nova Science Publishers, Inc.
Andreeva, A.V.; Shchukin, D.G. (2008): Materials Today, 11, 24-30.
Corrosion inhibitor (INH) loading into Corrosion inhibitor (INH) loading into mesoporous containersmesoporous containers
INHINH
INH
INH
INH
PEI
PSS
Polyelectrolyteshell
Skorb, E.V.; Fix, D.; Möhwald, H.; Shchukin, D.G. (2009): Adv. Funct. Mater., in print.
Inhibitor release from nanocontainersInhibitor release from nanocontainers
OH-OH-
OH-
controllable permeability of the polyelectrolyte shell
the release of the inhibitor startsonly after the begin of the corrosion
neutral
alkaline
pHpH--controlled release of the inhibitor from containers in controlled release of the inhibitor from containers in solutionsolution
Layer numberZe
ta Po
tentia
l (mV)
Time, min
% re
maine
d
Deposition step
INH
conte
nt mg
/1 g o
f silic
a
(A) scheme;
(B) changes of zeta potentialduring the procedure of polyelectrolyte shell formation;
(C) loading of the interior of titania containers with 2-(benzothiazol-2-ylsulfanyl)-succinic acid under vacuum;
(D) the release of inhibitor from nanocontainers at pH=10.1(a), and neutral pH (b)
The incorporation of the inhibitorThe incorporation of the inhibitor--loaded loaded containers with controlled releasecontainers with controlled release
CoatingPrecursor
subs
trat
e
sonication curing
Shchukin, D.G., Zheludkevich, M.L., Möhwald, H. (2007): J. Mater. Chem. 16, 4561-4566.
3µm
3µm
Release of the inhibitor from directlyRelease of the inhibitor from directly--impregnated coatings and coatings with impregnated coatings and coatings with containers. Conditions: under containers. Conditions: under deaerateddeaerated MilliMilli--Q water (no oxygen, no ions).Q water (no oxygen, no ions).
Coating directly doped with benzotriazole
0 1 2 3 4 50
20
40
60
80
100
% re
mai
ned
Days
0 1 2 3 4 50
20
40
60
80
100
% re
mai
ned
Days
Coating with the same amount of benzotriazole in nanocontainers with PE shell for controlledrelease
SelfSelf--healing effect on coatings with mesoporous containershealing effect on coatings with mesoporous containerswithout containers, 0.5 M NaCl, 14 days
inhibitor-loaded containers with polyelectrolyte shell
Halloysite nanotubesHalloysite nanotubesStructure
Dimensions
15 n
m50
nm
1 µm
0 50 100 150 2000.0
0.1
0.2
0.3
0.4
0.5
DV [1
0-3 c
m3 *Å
-1*g
-1]
Pore diameter [nm]
Pore size distributiondmax = 17.8 ± 0.7 nm
Lvov, Y.M.; Shchukin, D.G.; Möhwald, H., Price, R.R. (2008): ACS Nano 2, 814-820.
Loading of halloysite nanotubesLoading of halloysite nanotubes
Molybdate-loaded nanotube
Nanotube lumen
Shchukin, D.G., Lvov, Y. (2009): ACS Appl. Mater. and Interfaces, in print.
mechanical damage+
changed pHlocally triggeredrelease of inhibitor !
aggressive medium
metal
HalloysiteHalloysite--based feedback active antibased feedback active anti--corrosive corrosive coatingscoatings
homogeneous distribution
Fix, D.; Andreeva, D.V.; Lvov, Y.M.; Shchukin, D.G.; Möhwald, H. (2009): Adv. Funct. Mater., 11, 1720-1727. .
HalloysiteHalloysite--based coatingsbased coatings
Current density observations (SVET)
0 min
-10
1
-3
0
3
6
9
12
-1
01
y [mm]x [mm]
-10
1
-3
0
3
6
9
12
-1
01
y [mm]x [mm]
30 min
-10
1
-3
0
3
6
9
12
-1
01
y [mm]x [mm]
-10
1
-3
0
3
6
9
12
-1
01
y [mm]x [mm]
120 min
-10
1
-3
0
3
6
9
12
-1
01
y [mm]x [mm]
-10
1
-3
0
3
6
9
12
-1
01
y [mm]x [mm]
pure sol-gelcoating
…with inhibitorloaded halloysite
HalloysiteHalloysite--based coatingsbased coatings
Visual observations
pure sol-gelcoating
10 h in 0.1 NaCl
…with inhibitorloaded halloysite
10 h in 0.1 NaCl
Light triggered releaseLight triggered releaseKinetics of benzotriazole release from the containersmeso-TiO2/(PEI/PSS)2 and meso-TiO2:Ag/(PEI/PSS)2under pH change and under UV and IR irradiation, respectively.
0 10 20 30 40 50
0
10
20
30
40
50
60
70
80
90
100
32
1
rem
aind
er, %
time, min0 10 20 30 40 50
0
10
20
30
40
50
60
70
80
90
100
2
3
1
rem
aind
er, %
time, min
UV IRpH=7,2 pH=7,2
pH=7,2
pH=10,1
pH=10,1
pH=7,2 + IR
+ UV
light stimulated release (UV, IR) is much faster in comparison with pHstimulate release of incorporated into the container pore chemicals.
Skorb, E.V.; Skirtach, A.; Möhwald, H.; Shchukin, D.G. (2009): ACS Nano, in print.
Release of the inhibitor by lightRelease of the inhibitor by light
Benzotriazole-loaded mesoporous TiO2 containers with polyelectrolyte shell in SiOx/ZrOx sol-gel coating on Al
corrosion UV-healing
0 h 12 h 1 min UV irradiation0.1 M NaCl
E. V. Skorb, D. G. Shchukin, H. Möhwald and D. V. Sviridov, J. Mater. Chem., 2009, 19, 4931
Stabilization of pH change
Regeneration of coating defects
Release of inhibitor on demand
Barrier for aggressive
ions
Anticorrosion activity of polyelectrolyte multilayersAnticorrosion activity of polyelectrolyte multilayers
Carrier for corrosion inhibitor
Mobility of the swollen polyelectrolyte complex
Good adhesion to the substrate and sealing the surface defects
pH buffering activity
Andreeva, D.V.; Fix, D.; Möhwald, H., Shchukin, D.G. (2008): J. Mater. Chem. 18, 1738-1740.
Anticorrosion behavior of PE coating with buffer activityAnticorrosion behavior of PE coating with buffer activity
0.1 M NaCl 0 hr 1.5 hr 16 hr
10 bilayers of weak – strong PEPEI/PSS
Loading PE multilayers with corrosion inhibitorLoading PE multilayers with corrosion inhibitor
PSSInhibitorPSS
8-hydroxyquinoline
• Prevention inhibitor leakage• Release on demand • Reduce negative effect of inhibitor on coatings
Surface Surface passivationpassivation by 8by 8--hydroxiquinolinehydroxiquinoline
Y, µm Y, µm Y, µmX, µm X, µm X, µm
A
B
0 hr 6 hr 16 hrScanning vibration electrode technique, 0.1M NaCl
Andreeva, D.V.; Fix, D.; Möhwald, H., Shchukin, D.G. (2008): Adv. Mater., 20, 2789-2794.
SealingSealing effecteffect of polyelectrolytesof polyelectrolytes
10 µmFlow of the sealing polyelectrolyte
12hr 4 days 7 days 21 days
Visual corrosion & stability test in 0.5 M Visual corrosion & stability test in 0.5 M NaClNaCl solution solution
Frequencies from 20 kHz to 1 GHz; acoustic wavelengths from 10 to 10-4 cm far above molecular and atomic dimensions. Sonochemical effects are derived from acoustic cavitation (negative/positive pressure cycles).
The compression of bubbles during cavitation leads to the enormous concentration of energy: ~5200 K, ~1000 atm, heating and cooling rates ~ 1010 K/s
Power of Power of sonochemistrysonochemistry
Potential of ultrasound:• To perform chemistry and physics at high temperature but with a reactor near room
temperature.• Highly nonequilibrium structures can be made which meets the demands of technology as
well as physical sciences.• Surface energy is converted into chemical energy and its control can make rapid progress in
interfacial science.
Shchukin, D.G., Möhwald, H. (2006): Phys. Chem. Chem. Phys. 8, 3496-3506.
Surface of the cavitation Surface of the cavitation microbubblemicrobubble
~5200 K ~1900 K Room temperature
The work of evolution R(r) of a bubble with a radius r in metastable liquids is(thermodynamic nucleation theory):
vvv mPPrrrR )()(344)( 11
32 μμπσπ −+−+=
The probability of the formation of microbubblesis:
[ ]TkrR Bn /)(exp *−∝ω , R (r*) ~ σ3
For a typical surfactant concentration of cs= 1 mM and d= 10 µm the surfactant density is:
Surface active materials in the sonicated liquid will result in drastic reduction of the surface tension increasing the efficiency of the ultrasonic treatment. They decrease “surface”component of the evolution work and change the difference of the chemical potentialsbetween liquid and gas phases, which is of special interest for sonochemical reactions.
sΘ 142 10≈⋅
dvcs
π= mole/cm2
A monolayer coverage and hence a reduction of σ may be expected!
Cavitation microbubbles as templates Cavitation microbubbles as templates Polymer/polyelectrolyte air-containing microbubbles
500 1000 1500 2000 2500 3000 3500 4000
PSS
Span/Tween
PSS
Span/Tween
H2OInte
nsity
, a.u
.Raman shift, cm-1
heating, 45 ºC
Raman confocal microscopy spectra from an air-containing microbubbles (blue) and surrounding water solution (black).
Shchukin, D.G., Köhler, K., Möhwald, H., Sukhorukov, G.B.: (2005) Angew. Chem. Int. Ed., 44, 3310-3314.
Ultrasound in nanocontainer fabricationUltrasound in nanocontainer fabricationSiO2 containers
Grigoriev, D.; Miller, R.; Shchukin, D.; Möhwald, H. (2007): SMALL, 3, 665-671.
Son. LbL Coating
Active
material
polymer
US generator
General scheme:A. emulsification of active material presenting in oil phase in aqueous polymer
solution by ultrasonication;B. shell functionalization (if necessary);C. embedding of nanocontainers into coating film.
Containers with oil core and polymer shellContainers with oil core and polymer shell
0
10
20
30
40
50
60
1 10 100 1000 10000
Inte
nsity
(%)
Size (d.nm)
Statistics Graph (1 measurements)
Ultrasound in nanocontainer fabricationUltrasound in nanocontainer fabricationOil-filled polymer containers
Teng, X.; Shchukin, D.G.; Möhwald, H. (2007): Adv. Funct. Mater.,17, 1273-1278.
Containers with oil core and polymer shellContainers with oil core and polymer shell
Polystyrene shell Polyurithane shell
Protein shell
Teng, X.; Shchukin, D.G.; Möhwald, H. (2008): Langmuir,24, 383-389.
Containers with oil core and polymer shellContainers with oil core and polymer shell
0 2.50 5.00
0
2.50
5.00
AFM image of nanocontainers entrapped into polymer film
Borodina T., unpublished results.
Containers with oil core and polymer shellContainers with oil core and polymer shell
20 µm 20 µm 20 µm
CLSM of the nanocontainers embedded into polymer coating
1µm
1µm
SEM photographs
Release profile of VE from bioactive film in Release profile of VE from bioactive film in HH22O/EtOH solutionO/EtOH solution
AcknowledgementsAcknowledgements
Max Planck Institute of Colloidsand Interfaces:
Prof. Dr. Helmuth Möhwald
Dr. D. Grigoriev, Dr. X. Teng, Dr. E. Skorb, Dr. D. Andreeva, D. Fix, A. Praast, Dr. I. Dönch, Dr. T. Borodina, Dr. Y.-S. Han, M. Haase, Dr. J. Hartmann
Institute for Micromanufacturing, Louisiana Tech:Prof. Dr. Y. Lvov