laser nanostructuring of soft matter - university of · pdf filelaser nanostructuring of soft...
Post on 26-Mar-2018
224 Views
Preview:
TRANSCRIPT
Laser Nanostructuring of Soft Matter
Marta Castillejo
Instituto de Química Física Rocasolano, CSIC
Madrid, Spain
School on Lasers in Materials Science July 2012, Isola di San Servolo
Consejo Superior de Investigaciones Científicas Spanish Council for Scientific Research (CSIC) Largest public research organization in Spain
Instituto de Química Física Rocasolano
Madrid
Lasers, nanostructures and materials processing
Instituto de Química Física Rocasolano, CSIC
Obtain new knowledge on physicochemical control mechanisms of micro- and nanofabrication of different types of materials using processing techniques based on irradiation and ablation with pulsed lasers in ns and fs domains.
Research of interest in technological areas of photonics, photovoltaics, nonlinear optics, biomedicine and cultural heritage.
Fabrication of Thin Films and Nanostructures by Pulsed
Laser Deposition
Lasers in Conservation of Cultural Heritage
http://lanamap.iqfr.csic.es
Laser micro- and nanostructuring
Ablation Mechanisms and Plume Dynamics
Soft Matter
Soft
Mat
ter
7(2
0),
20
11
|
Nanostructuring
htt
p:/
/ww
w.z
yvex
lab
s.co
m/E
IPB
Nu
G/2
00
5M
icro
Gra
ph
.htm
l
Laser
Pulses of 130 as, CUSBO, Milan
T4 Bacteriophage, 25,000X
Soft Matter
What is it? polymers, colloids, foams, gels, liquid crystals, wide variety of self-organizing materials
Basic properties Materials with length scales much
larger than molecules, Many degrees of freedom: Properties
dominated by thermal fluctuations, Easily deformed by applied external
stresses. http://physics.oulu.fi
Mesoscopic size ≈ 100 nm
Soft Matter
Why is it interesting?
Unpredictable behaviour from molecular constituents due to self-organization into mesoscopic structures (reveals quantum mechanical properties).
Electronic, optical properties differ from bulk material due to quantum confinement effects.
Physics meets Chemistry meets Biology. Science (2009) 323, 237
Who started it all? P. G de Gennes Nobel Prize, 1991 For discovering that "methods developed for studying order phenomena in simple systems can be generalized to more complex forms of matter, in particular to liquid crystals and polymers“.
http://www.nobelprize.org
Geckos
Correlation between Multiscale Structure and Property
http://biomaterials.bme.northwestern.edu
Inspiration and Learning from Nature
Learning from Nature to develop novel functional (soft) materials bioinspired, multiscale structured materials, bio-nanomaterials (bio-nanoparticles), hybrid organic/inorganic implant materials, smart biomaterials.
Adv. Mat. 2008, 20, 2842
Correlation between Multiscale Structure and Property
Ad
v. F
un
ct. M
ater
. 20
12
, 2
2, 1
24
6
Gecko-inspired angled elastomer micropillars
Soft Matter
Soft
Mat
ter
7(2
0),
20
11
|
Nanostructuring
htt
p:/
/ww
w.z
yvex
lab
s.co
m/E
IPB
Nu
G/2
00
5M
icro
Gra
ph
.htm
l
Laser
Pulses of 130 as, CUSBO, Milan
T4 Bacteriophage, 25,000X
Variety of key techniques used extensively for generating structures at the
nanoscale. Nanofabrication
Some limitations
Spatial resolution,
Based in multiple-steps procedures,
Involve use of clean-room facilities,
Difficult to scale to wafer-like sizes.
Martín et al., Macromolecules,42 (2009) 5395.
Fluoropolymer NTs
templated by AAO
Nanoporous alumina
membranes (AAO
templates)
Inorganic templates
Nanoimprint Lithography (NIL)
LIPSS
LIFT
PLD
MAPLE 2-3 PP
OTAN
Others
Precise, non-contact, flexible set-ups: all environments, all materials
Ability to manipulate micro- and nanoscale,
Control of the physicochemical behaviour of treated material,
Specific advantages of ultrashort pulses (fs)
Laser Nanofabrication
A wealth of laser-based tools and methods with specific capabilities
Laser printing fabrication of various types of components:
TFTs, OLEDs, sensors, energy harvesters, etc.
http://www.e-lift-project.eu
Polymer coated sensor arrays
Organic Light Emitting Diodes
Laser Induced Forward Transfer (LIFT)
Neural tissue engineering 3D scaffolds, Biofabrication 3 (2011) 045005
High-res 3D scaffolds on biomaterials and biocompatible materials for tissue engineering
Two-photon polymerization of hybrid materials for nanophotonics
http
://ww
w.p
ho
ton
ics4life.eu
Multiphoton polymerization
http
://ww
w.sigm
aaldrich
.com
htt
p:/
/las
ie.a
p.e
ng.
osa
ka-u
.ac.
jp/r
es_2
pfa
b.h
tml
Optical trap assisted nanopatterning (OTAN)
AFM image of MAPLE-deposited polymer glass, Nature Mat., 2012 ; DOI 10.10.38
Later in this School! PLD, MAPLE
Pattern nanoscale features on model polyimide rough surface. Taking advantage of plasmonic field
enhancement. IOP Nanotech., 23 (2012) 165304.
Nanopatterning on rough surfaces using optically trapped microspheres
Polymers
Fundamental components of soft matter.
Intrinsic structure of semicrystalline polymers: alternate nm size regions of crystalline/ amorphous phases. http://www.polymerexpert.biz
Small 2011, 7, 1288
Nanoconfinement in polymeric materials
Large effects on structure/ dynamics
Affect phase transitions/ physical processes
Crucial for development of materials for specific applications
Critical for applications as efficient structural materials
Improve chain design,
Tuning semicrystalline structure,
Control of nanostructure by confinement in nm range.
Polymers
2D meshed microfluidic channels
inside IPL polymer fabricated by 2PP
method, Light: Science & Applications
(2012) 1, doi:10.1038/lsa.2012.6
Switchable Diffraction Gratings,
Adv. Funct. Mat. 18 (2008) 1617
Electro-optic activity of
nonlinear optical polymer,
Polymer Chem 50 (2012)
1254.
Applications of nanoconfined polymer and biopolymer materials
Photonics and Photovoltaics,
High-density magnetic data storage devices
Microchip reactors
Biosensing and Biomedicine
Thin microstructured plastic
sheet on solar panel to
increase light absorption
(Genie Lens Technologies)
Fabrication of wafer-scale
polystyrene photonic crystal,
J. Mat. Chem. 2011, 37.
Laser Nanostructuring of Polymers: Bubbles, Ripples
and Applications
1. Laser Foaming
2. Laser Induced Periodic Surface Structures (LIPSS)
3. Applications: tissue engineering and SERS
(a) (b)(a) (b)Synthetic polymers Polycarbonate Bis Phenol A (PC)
Poly (ethylene terephthalate), (PET) x=2
Poly (trimethylene terephthalate), (PTT) x=3
Poly (vinyliden fluoride), (PVDF)
(a) (b)(a) (b)
LIPSS on polymers and biopolymers
Biopolymers
Chitosan
Collagen
Gelatine
Starch
ω ω
Thin films by spin coating
Thickness ~ 150 nm
Ra< 1 nm
LIPSS on polymers and biopolymers
Thin films preparation
Self-standing films by dropcasting
Thickness ~ 20-200 mm
Laser Nanostructuring of Polymers: Bubbles, Ripples
and Applications
1. Laser Foaming
2. Laser Induced Periodic Surface Structures (LIPSS)
3. Applications: tissue engineering and SERS
20 mm
Gelatine Tiitanium: sapphire laser
800 nm, 90 fs
Laser submicro-foaming by irradiation with fs pulses
Appl. Surf. Sci., 253 (2007) 642. Appl. Surf. Sci. 254 (2007) 1179. Appl.Phys A, 93 (2008) 2009
5 mm 5 mm
Single pulse laser treatment yields a foamy layer with nanofibrous properties
Mimicks nanostructure of fibrillar network of living tissues.
800 nm, 3.2 J/cm2
400 nm, 1.5 J/cm2 400 nm, 1.9 J/cm2
266 nm, 0.2 J/cm2 266 nm, 2.2 J/cm2
800 nm, 2.2 J/cm2
10 mm
800 nm, 2.2 J/cm2
Pores or bubbles have a size of the order of the irradiation wavelength.
Most of the time interconnected: of interest for potential biomedical applications.
Collagen Gelatine
Appl. Surf. Sci., 253 (2007) 642.
Ti:Sa laser, 90 fs
Laser submicro-foaming by irradiation with fs pulses
10 mm
Laser foamed chitosan
50 mm
Cell culture of
mouse NIH/3T3
fibroblasts
Laser foamed chitosan for cell culture
Lamellipodia
Chitosan film, one pulse, 248 nm, 20 ns, 2 J/cm2, cell culture of 3 days
Cell
density/
num
ber
of cells
/m
m2
Days of culture
Non-irradiated Irradiated
Castillejo et al., Appl. Surf. Sci. 2012, 258, 8919.
Foamed chitosan as substrates for substrates for cell culture
Fibroblast cells
Laser Nanostructuring of Polymers: Bubbles, Ripples
and Applications
1. Laser Foaming
2. Laser Induced Periodic Surface Structures (LIPSS)
3. Applications: tissue engineering and SERS
Contribution of several processes
Non-thermal chain scissoring and migration
Amorphization of crystalline domains
Temperature increase above Tg
Photoxidation, …
Fi
The classical mechanism
isin
n
Fs regime
Extensive work in different materials
(metals, SCs)
Very few studies on polymers
Studies needed for assessment of
mechanisms
LIPSS on polymers and biopolymers
In air, linearly polarized Wavelength Pulse duration
ArF excimer
Nd:YAG (4th harmonic)
Nd:YAG (5th harmonic)
193 nm
213 nm
266 nm
15 ns
15 ns
6 ns
Ti:sapphire (3rd harmonic) 265 nm 260 fs
Ti:sapphire 795 nm 120 fs
LIPSS on polymers and biopolymers
Rebollar et al.:
Annual report HASYLAB , 2010.
Langmuir, 2011, 27, 5596.
Appl. Phys. Lett. 2012, 100, 041106
Martín-Fabiani et al. Langmuir 2012, 28, 7938.
STRUCTURAL ANALYSIS
AFM: Real space
Grazing Incidence X ray diffraction: Reciprocal space
qz
qy
a
w
ai
LIPSS filmm
m (qy =0)
h
(a = 0)
Direct X-ray beam
Incident X-
ray beam
ai
h
yq
2
Structural analysis by Grazing Incidence X-Ray Scattering
GISAXS: Two orthogonal scattering vectors:
structural correlations
BW4 beamline, HASYLAB (DESY, Hamburg)
0.13808 nm, ai= 0.4 º
a exit angle
w out of
scattering
plane angle
aa
sinsin
2 izq
┴ to film plane
a
cos
2 senqy
‖ to film plane
5x5 mm2
fs-LIPSS
ns-LIPSS
LIPSS on polymers and biopolymers Parallel to laser polarization
Period≈ wavelength
0 1000 2000 3000 40000
100
200
300
AFM
GISAXS
L (
nm
)
Number of pulses
4 6 8 10 12 140
100
200
300
AFM
GISAXS
L (
nm
)
Fluence (mJ/cm2)
(a)
(b)
(b) 100 (c) 300
(d) 600 (e) 1200 (f) 6000
mm
mm
mm
mmmm0 0 0
0 02 2
2 2 2
0 2mm0 0 0
0 0 0
160 160 160
160 160 160
nm
nm
(a) Non-irrad.
PTT, 266 nm, 6 ns,7 mJ/cm2 LIPSS Period
10x10 mm2
Periods ≈ laser wavelength
Good correlation AFM and GISAXS (validation)
Martín-Fabiani et al. Langmuir 2012, 28, 7938.
PVDF, 266 nm, wide
range of fluences
10 nm
-10 nm
10 nm 300 nm
-300 nm
40 nm
-40 nm
20 nm
-20 nm
100 nm
-100 nm
(a) non-irrad. (b) 85 mJ/cm2 (c) 140 mJ/cm2
(d) non-irrad. (e) 7 mJ/cm2 (f) 13 mJ/cm2
PVDF
PTT thermally treated
-10 nm0 1 2 3 40
1
2
3
4
mm
mm
0 1 2 3 40
1
2
3
4
mm
mm
0 2 4 6 80
2
4
6
8
mm
mm
0 2 4 6 80
2
4
6
8
mm
mm
0 10 20 30 400
10
20
30
40
mm
mm
0 1 2 3 40
1
2
3
4
mm
mm
No LIPSS in
semicrystalline
polymers
PTT, 266 nm,
No Bragg reflections: no LIPSS-
induced crystallization
2D-GIWAXS: information on crystalline
structure and crystal orientation
7 mJ/cm2, 106 mJ/cm2
PTT, 532 nm
No LIPSS at
weakly
absorbed
wavelengths
6000 pulses
6 ns pulses
• LIPSS in amorphous polymers when T>
Tg (surface devitrification).
• Weakly absorbing polymers T< Tg.
• Crystalinity prevents softening necessary
for LIPSS.
Temperature increase: Solving the one-dimensional
heat conduction equation
0 100 200 300 400 500 60020
40
60
80
100
120
140
160Tg
9 mJ/cm2
Te
mp
era
ture
/ o
C
Time/ ns
0 nm
30 nm
100 nm
140 nm
5 mJ/cm2
0 100 200 300 400 500 60020
30
40
50
60
70
80Tg
5 mJ/cm2
Te
mp
era
ture
/ 0C
Time/ ns
0 nm
30 nm
100 nm
140 nm
3 mJ/cm2
(a) PET
(b) PC
(c) PVDF
0 100 200 300 400 500 60020
30
40
50
60
140 mJ/cm2
0 nm
Te
mp
era
ture
/ o
C
Time/ ns
0 100 200 300 400 500 60020
40
60
80
100
120
140
160Tg
9 mJ/cm2
Te
mp
era
ture
/ o
C
Time/ ns
0 nm
30 nm
100 nm
140 nm
5 mJ/cm2
0 100 200 300 400 500 60020
30
40
50
60
70
80Tg
5 mJ/cm2
Te
mp
era
ture
/ 0C
Time/ ns
0 nm
30 nm
100 nm
140 nm
3 mJ/cm2
(a) PET
(b) PC
(c) PVDF
0 100 200 300 400 500 60020
30
40
50
60
140 mJ/cm2
0 nm
Te
mp
era
ture
/ o
C
Time/ ns
PET
PVDF
266 nm, 6 ns
Tg= -35 ºC
Tm= 248 º C
Tg= 75 ºC
Tm= 252 º C
ns-LIPSS on polymers: Mechanisms?
Rebollar et al, Langmuir, 2011, 27, 5596.
(a) Non-irrad.
(b) 300 pulses
-40 nm
80 nm
-90 nm
9 nm
-5 nm
50 nm
-50 nm
40 nm(c) 700 pulses
(d) 1200 pulses
10 nm
-10 nm
10 nm 300 nm
-300 nm
40 nm
-40 nm
20 nm
-20 nm
100 nm
-100 nm
(a) non-irrad. (b) 85 mJ/cm2 (c) 140 mJ/cm2
(d) non-irrad. (e) 7 mJ/cm2 (f) 13 mJ/cm2
PVDF
PTT thermally treated
-10 nm0 1 2 3 40
1
2
3
4
mm
mm
0 1 2 3 40
1
2
3
4
mm
mm
0 2 4 6 80
2
4
6
8
mm
mm
0 2 4 6 80
2
4
6
8
mm
mm
0 10 20 30 400
10
20
30
40
mm
mm
0 1 2 3 40
1
2
3
4
mm
mm
Ei≈ 6.5 eV 413 nm
265 nm 795 nm
e plasma energy density
r density
Cp heat capacity
pCT
r
e icr E
4
9re
rcr critical free
electron density
Vogel et al.. Appl. Phys. B (2005)
2
0
2)/2(
e
mccr
er
mc mass of quasi-free
electron in conduction band
Rebollar et al., Appl. Phys. Lett. 2012, 100, 041106
Generation of free electrons by MPI
fs-LIPSS on polymers: Mechanisms?
T scales inversely with : T265 ≈ 10XT795
larger N and F needed for LIPSS at longer
Further morphological control of nanostructures
Dependence of LIPSS period with
angle of incidence
)sin(
n
Structures using
circularly polarized light
5x5 mm2
PET, 266 nm, 6 ns,
7 mJ/cm2, 1200
Gold-coated polymer LIPSS as substrates for SERS
Ns-PLD, 213 nm,
2 J/cm2
PET, PTT LIPSS substrates 0 10000 20000 30000 40000
0
10
20
30
40
50
Deposit t
hic
kness (
nm
)
Number of pulses
Gold layer preserves LIPSS relief
Tests with
Benzenethiol
Gold-coated LIPSS for SERS
Raman signal enhancement:
10 nm gold layer on LIPSS
950 1000 1050 1100
36000 pulses
24000 pulses
Inte
nsity (
arb
.units)
Wavenumber (cm-1)
12000 pulses
BT 10-5 M
Raman signal depends on
Thickness of gold layer
Analyte concentration
10-6
10-5
10-4
10-3
2000
3000
4000
[BT] (M)
Tests with
Benzenethiol
Rebollar et al., submitted.
Enhancement factor of 8 orders of
magnitude
top related