Boron and Aluminum Nanoparticles Functionalized with Ionic Liquids
Boron and Aluminum Nanoparticles Functionalized with Ionic Liquids
Boron and Aluminum Nanoparticles Functionalized with Ionic Liquids
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Nanoparticle preparation<br />
Ball Milling Method<br />
Physically grind micron size feedstock down<br />
to the nanoscale regime using planetary ball<br />
milling <strong>with</strong> WC balls<br />
pump<br />
Particles are coated <strong>with</strong> various<br />
lig<strong>and</strong>s/capping agents to promote<br />
suspension in a variety of fuels <strong>and</strong>/or to<br />
protect them from unwanted oxidation<br />
Particle Characterization<br />
Chemical composition: XPS, FTIR, TGA<br />
Particle Size: DLS, SEM, TEM<br />
Retsch PM400 ball mill<br />
1
~50 nm particles<br />
separated by settling<br />
big particles<br />
200 nm<br />
SEM image of
Unoxidized <strong>Boron</strong> <strong>Nanoparticles</strong><br />
B 1s Region Scan<br />
• Elemental B1s peak observed<br />
at ~188 eV, B 3+ at ~193 eV<br />
• Nanosized boron<br />
immediately formed oxide<br />
upon exposure to air as the<br />
XPS samples were prepared.<br />
• Oleic acid prevented<br />
oxidation of the fresh boron<br />
surfaces formed during the<br />
milling process.
Catalyst Coated, Unoxidized <strong>Boron</strong><br />
<strong>Nanoparticles</strong><br />
<strong>Boron</strong> core<br />
CeO 2 catalyst<br />
Oleic Acid<br />
C °<br />
A<br />
B °<br />
XPS<br />
XPS suggests<br />
the presence of<br />
a low binding<br />
energy boride<br />
species (Ce x B y )<br />
STEM<br />
CeO 2 exists as patch of isl<strong>and</strong> on a<br />
boron nanoparticle
<strong>Boron</strong> <strong>Nanoparticles</strong> <strong>with</strong> Polar Surfactants<br />
<strong>Boron</strong> Powder + ⅛” WC balls<br />
80:1 BPR<br />
3 hrs dry milling<br />
+ Surfactant (<strong>Ionic</strong> Liquid,<br />
Et 2 NH, Et 3 N, Ethanolamine)<br />
~10 % total volume<br />
3 hrs milling<br />
+ Solvent (Ethanol)<br />
18 hrs milling<br />
Samples washed <strong>with</strong> EtOH to<br />
remove excess surfactant<br />
www.retsch.com<br />
4 x 250 ml capacity
Method of Preparation: Ball Milling<br />
B-<strong>Ionic</strong> Liquid Et3N Et 2 NH <strong>Boron</strong> in EtOH Wet Milled<br />
<strong>Boron</strong> in EtOH<br />
Solubility /Dispersibility in Ethanol (polar solvent)<br />
Characterize size of particles using:<br />
SEM, DLS<br />
Characterize chemical composition using:<br />
EDX-STEM, XPS, FTIR
<strong>Boron</strong>-<strong>Ionic</strong> Liquid Particle Size<br />
1<br />
0.9<br />
0.8<br />
0.7<br />
0.6<br />
0.5<br />
Size weighted<br />
209 nm<br />
(59%)<br />
79 nm<br />
(41%)<br />
0<br />
1<br />
0.9 Number<br />
0.8<br />
weighted<br />
0.7<br />
0.6<br />
0.5<br />
78 nm<br />
(93%)<br />
0.4<br />
0.3<br />
201nm<br />
0.2<br />
(7%)<br />
0.1<br />
0<br />
SEM Image of <strong>Boron</strong> <strong>Nanoparticles</strong><br />
on TEM Grid<br />
DLS Measurement of Particle Size<br />
0.4<br />
0.3<br />
0.2<br />
0.1<br />
10 15 22 32 48 70 104 154 227 335 495 732<br />
10 15 22 32 48 70 104 154 227 335 495 732
<strong>Boron</strong>, Nitrogen Species<br />
B1s Region XPS of <strong>Boron</strong> milled <strong>with</strong> <strong>Ionic</strong> Liquid in<br />
EtOH<br />
3500<br />
3500<br />
N1s Region XPS of <strong>Boron</strong> milled <strong>with</strong> <strong>Ionic</strong> Liquid<br />
in EtOH<br />
3000<br />
2500<br />
2000<br />
1500<br />
1000<br />
500<br />
B 0 = 188 eV<br />
3000<br />
N-B= 398 eV<br />
2500<br />
2000<br />
1500<br />
1000 400 eV<br />
Organic N<br />
500<br />
0<br />
200<br />
195<br />
190<br />
185<br />
180<br />
0<br />
405<br />
403<br />
401<br />
399<br />
397<br />
395<br />
393<br />
391
<strong>Boron</strong>, Nitrogen Species<br />
8000<br />
193 eV<br />
191 eV<br />
188 eV<br />
7000<br />
N1s Region XPS of <strong>Boron</strong> milled <strong>with</strong> <strong>Ionic</strong> Liquid<br />
in EtOH<br />
6000<br />
3500<br />
5000<br />
4000<br />
3000<br />
2000<br />
1000<br />
B 0 = 188 eV<br />
3000<br />
N-B= 398 eV<br />
2500<br />
2000<br />
1500<br />
1000 400 eV<br />
Organic N<br />
500<br />
0<br />
197<br />
192<br />
187<br />
182<br />
0<br />
405<br />
403<br />
401<br />
399<br />
397<br />
395<br />
393<br />
391
Diethylamine Surfactants<br />
1<br />
Size<br />
Weighted<br />
0.5<br />
189 nm<br />
(43%)<br />
86 nm<br />
(57%)<br />
0<br />
1<br />
Number<br />
Weighted<br />
11 20 35 63 113 203 365 655<br />
0.5<br />
81 nm<br />
(93%)<br />
178 nm<br />
(7%)<br />
0<br />
11 20 35 63 113 203 365 655
XPS<br />
16000<br />
2800<br />
14000<br />
B 0 = 188 eV<br />
N-B= 398 eV<br />
2300<br />
12000<br />
10000<br />
B-N = 192 eV<br />
1800<br />
8000<br />
Light sputter<br />
1300<br />
6000<br />
4000<br />
800<br />
400 eV<br />
Organic N<br />
2000<br />
300<br />
Unsputtered<br />
0<br />
195<br />
190<br />
185<br />
180<br />
410<br />
-200<br />
405<br />
400<br />
395<br />
390<br />
B1s Region XPS of <strong>Boron</strong> milled <strong>with</strong> Et 2 NH in EtOH<br />
N1s Region XPS of <strong>Boron</strong> milled <strong>with</strong> Et 2 NH in EtOH
Triethylamine Surfactants<br />
1<br />
Size<br />
Weighted<br />
0.5<br />
59 nm<br />
(59%)<br />
176 nm<br />
(41%)<br />
0<br />
1<br />
Number<br />
Weighted<br />
11 20 35 63 113 203 365 655<br />
0.5<br />
0<br />
57 nm<br />
(97%)<br />
165 nm<br />
(3%)<br />
11 20 35 63 113 203 365 655
XPS<br />
10000<br />
B 0 = 188 eV<br />
1300<br />
9000<br />
N-B= 398 eV<br />
8000<br />
1100<br />
7000<br />
900<br />
6000<br />
B-N = 192 eV<br />
5000<br />
60 sec sputter<br />
700<br />
4000<br />
500<br />
3000<br />
2000<br />
300<br />
400 eV<br />
Organic N<br />
1000<br />
0<br />
-1000<br />
197<br />
192<br />
187<br />
Unsputtered<br />
182<br />
100<br />
408<br />
-100<br />
403<br />
398<br />
393<br />
B1s Region XPS of <strong>Boron</strong> milled <strong>with</strong> Et 3 N in EtOH<br />
N1s Region XPS of <strong>Boron</strong> milled <strong>with</strong> Et 3 N in EtOH
Temperatrue o C<br />
Combustion testing in a turbulent flame calorimeter<br />
49<br />
~3% <strong>Boron</strong> Loaded Ethanol vs. Pure Ethanol<br />
44<br />
39<br />
34<br />
29<br />
24<br />
<strong>Boron</strong> loaded Etoh ∆T = 27.45 o C<br />
Temperature Increase = 1.18 o C<br />
A 4.49% increase<br />
Increase is consistent <strong>with</strong><br />
complete combustion of the<br />
boron. Burner has difficulties<br />
<strong>with</strong> higher loadings.<br />
run 1<br />
run 2<br />
run 3<br />
<strong>Boron</strong> run<br />
19<br />
0 100 200 300 400 500 600<br />
Time (sec)
<strong>Boron</strong> nanoparticles functionalized <strong>with</strong> ionic liquid<br />
Dynamic Light<br />
Scattering (DLS)<br />
of particles<br />
suspended in<br />
EtOH<br />
1<br />
0.5<br />
104 nm<br />
0<br />
10 15 22 32 48 70 104 154 227 335 495 732<br />
Particle diameter (nm)<br />
15
Acknowledgment<br />
University of Utah Chemistry Department<br />
Prof. Scott L. Anderson<br />
Anderson group:<br />
William Kunkel<br />
David Bell<br />
Eric Baxter<br />
Darby Lewis<br />
Dr. Dae Jung Kim<br />
Matt Kane<br />
Sloan Roberts<br />
Mark Wirth<br />
Ashley Becksted<br />
Sebastian Proch<br />
Our collaborators:<br />
Tommy Hawkins<br />
Steven Son<br />
Robin Rodgers<br />
Michael Berman<br />
Stefan Schneider<br />
Jerry Boatz<br />
Support: Air Force Office of Scientific Research<br />
Grant FA9550-08-1-0400<br />
16
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