University of California Davis
Lipid/Polymer Mixtures at Air/Water Interface
HO
O
8
Peg8S
O
O
H
P
O
N
O
O
14
O
O
14
O
DPPC
Pressure-area isotherm of DPPC/PEG8S
0min
20min
1min
30min
2min
3min
45min
1hour
10min
1hour
30min
Time evolution studies of metastable DPPC/PEG8S domains Langmuir trough coupled to an
imaging ellipsometer
Building Biosensors
O
n
Alkyl chain
(can also be
Cholesterol)
Poly(ethylene glycol)
Si
O
O O O
Trichlorosilane
FITC doped glass will
fluoresce differently
depending of changes in pH.
pH 9.0
pH 4.0
Silicon wafer
Florescent glass
NIPAAM
NaMAA
Initiator
Lipid
pH sensitive copolymer expands and compresses as H+ pumps through the
membrane via the gramicidin ion channel.
Gramicidin A
Directed Assembly using Patterned Brushes and Composite
Nanoparticles
Polymer-coated nanoparticles
patterned onto a gold surface
General
Scheme
S
Si
O
N
H
S
n
O
CN
O
CdS
SiO2
N
11
S
TEM image of polymer
encapsulated nanoparticles
Detail of RAFT-based tethering methodology
Neutron Surface Reflectivity of Dry and Solvated
ATRP Grafted Polystyrene on Si and SiO2 Wafers
Brush compression vs. brush interdigitation
Bulk polymerization of styrene Mn vs. time
Polymerization reaction vessel
60
9-96
Glue region
-3
Mn x (10 )
50
Evacuation/backfill port
Krytox ® grease
coated ground
glass joint
40
30
Honey region
20
10
Coffee region
0
0
1
2
3
Time (h)
4
5
Addition and
sampling arm
Surface platform
Reflectivity plot
10-5
Scattering length density vs. dry thickness
R* + X-Mtn+1/L
R-X + Mt /L
10-5 Chi^2=1.92
kdeact
-10
10
kp
Monomer
-11
10
-12
10
0
0.05
0.1
0.15
0.2
0.25
0.3
-1
Q (Å )
ATRP of styrene “grafting from” Si wafer
PS brush thickness vs. Mn
800
O
+
600
10 20 30 40 50 60 70 80
-3
Mn x (10 )
-100
-50
Si
O
O
O
O
Si
Si
O
CuBr : CuBr2 : Styrene : PMDETA : EbiB = 9.6 : 0.48 : 960 : 10.8 : 1
CA after ATRP initiator deposition : 71º
GPC: Mn = 11,000 g/mol, PDI = 1.11
CA after polymerization : 112º
0
50
100
150
200
Z, Distance (Å)
O
Br
106
Si
0
0
SiO2
100
106
PS
1
PS
200
Br
Br
O
Silicon
2
Air
300
O
CuBr, CuBr2, PMDETA
Si
(SLD)
10-5 (1.3)
10-6 (1.3)
10-62 (1.3)
10-66 (1.54)
10-67 (1.3)
Linear Fit (R=0.9948)
400
Si
O
500
n
90 oC
O
O
Si
O
Si
Si
Si
O
O
Br
O
O
700
Thickness (Å)
O
O
O Si
3
Native Oxide
Reflectivity, RQ
kact
n
-2
-9
-6
10
Atom Transfer Radical Polymerization (ATRP) Schematic
Scattering Length Density, b x 10 Å
-8
4
10
250
High-Efficiency Stepwise Contraction and Adsorption
Nanolithography (h-SCAN)
AFM image of BD-R
AFM image of mold C
Statistical analysis of AFM image
Statistical analysis of AFM image
Peak width (nm)
183.2 ± (7.500)
Peak width (nm)
679.2 ± (43.14)
Valley width (nm)
120.9 ± (5.670)
Valley width (nm)
1,498 ± (31.62)
Peak height (nm)
21.59 ± (3.400)
Peak height (nm)
572.9 ± (30.26)
Pre-elastomer coating on
stretched PDMS substrate
Diagram of the layers of a DL Blue-ray disc
http://www.tdk.co.jp/teaah01/aah17200.htm
Contraction
Cure / Mold removal
Imprint epoxy mold master A
AFM image of mold A
AFM image of mold B
Imprint epoxy master mold B on preelastomer coated stretched PDMS
substrate
Cure / Mold removal
Epoxy PDMS mold replication C
Epoxy master mold B removal
Contraction
Epoxy PDMS mold replication B
Statistical analysis of AFM image
Statistical analysis of AFM image
Peak width (nm)
1,855 ± (37.87)
Peak width (nm)
1,430 ± (35.33)
Valley width (nm)
1,979 ± (32.81)
Valley width (nm)
1,774 ± (31.28)
Peak height (nm)
516.7 ± (7.804)
Peak height (nm)
560 ± (16.6)
Erik Woodbury
John Ell
Prof. Timothy Patten
Rita El-khouri
Jennifer Cash