Experiments
• Synthesis of Nano Particles and
Encapsulation
• Synthesis of Hexagonal Mesoporous
Silica & Carbon
• Synthesis of Organic and Carbon
Xerogels
• Synthesis of Silver NanoWires
Demostration Experiments
• Sol-Gel Synthesis via TMOS
• Sol-Gel Synthysis using Sodium silicate
better known as furnace cement.
• Ultrasonic synthesis of TMOS
SOL-GEL SCIENCE
Mix the reactives
• Gelification
Hydrolysis and Condesation
reactions take place
Sol
• Aging
• Soaking
Gelification
Gel
Aging
Drying
Gel
Aerogel
Gelification
OR
+
Si
OR
Mix reactives
OR
OR
H2O
OR
OR
OR
OR
Hydrolysis and Condesation
reactions take place
OR
+
Si
OR
OR
HO
OR
Si
OR
Gel
OH
+
HO
OR
OR
Aging
Gel
O
Si
OR
OR
Sol
Gelification
OR
OR
Si
OR
OR
OR
+
ROH
+
H2O
OR
Si
OR
OR
OR
OR
Si
ROH
OR
OR
Si
OR
+
Si
HO
O
Si
OR
OR
Designing Nanomaterials
First Step
Silica Solution
Precursor: Tetraetilortosilicate
Si(OCH2CH3)4
Solvent: Ethanol
Catalyst: OxalicAcid
Modifications
pH (final product)
Temperature (crystal phase)
Precursor (Type of material)
Time (Strength)
etc
(I)
SOL-GEL SYNTHESIS OF AEROGELS
Aerogels are a unique, nanostrutured material derived from gels. Gels are a novel class
of material exhibiting solid-like behavior although consisting predominantly of a liquid phase.
Their solidity derives from a continuous interpenetrating framework that, in essence, acts like a
molecular scaffold extending throughout the liquid. This perspective of a gel as a molecular
web in a liquid has found many industrial applications.
Figure 1:
A silicon oxide low density aerogel
Gelification
OR
+
Si
OR
Mix reactives
OR
OR
H2O
OR
OR
OR
OR
Hydrolysis and Condesation
reactions take place
OR
+
Si
OR
OR
HO
OR
Si
OR
Gel
OH
+
HO
OR
OR
Aging
Gel
O
Si
OR
OR
Sol
Gelification
OR
OR
Si
OR
OR
OR
+
ROH
+
H2O
OR
Si
OR
OR
OR
OR
Si
ROH
OR
OR
Si
OR
+
Si
HO
O
Si
OR
OR
Synthesis of Nano Particles and
Encapsulation
• Synthsis of Tiatnium and silica
nanoparticles
• Sol-Gel Encapsulation
• Jorge Arias
Encapsulated Dendrimer
•
The following figure shows mono dispersed
Starburst PAMAM polyamidoamine dendrimers
encapsulated in a sol-gel matrix of silica at 25 wt.
%. Surface area analysis shows the material
surface area was 617 m2/g. The dark spheres in
Figure 1 dispersed throughout the silica matrix
show diameters similar to their hydrodynamic
values for this dendrimer in solution.
PAMMA Dendrimer
Sol-Gel Encapsulated Dendrimer
Gelification
OR
+
Si
OR
Mix reactives
OR
OR
H2O
OR
OR
OR
OR
Hydrolysis and Condesation
reactions take place
OR
+
Si
OR
OR
HO
OR
Si
OR
Gel
OH
+
HO
OR
OR
Aging
Gel
O
Si
OR
OR
Sol
Gelification
OR
OR
Si
OR
OR
OR
+
ROH
+
H2O
OR
Si
OR
OR
OR
OR
Si
ROH
OR
OR
Si
OR
+
Si
HO
O
Si
OR
OR
Synthesis of Hexagonal
Mesoporous Silica & Carbon
• This lab couples the hydrolysis and
condensation of TEOS or other silica
sources with Structure directing agents such
as surfactants or polymers .
• It also uses the final silica mesoporous
material as a template to synthesize a high
surface area, hexagonal pure carbon
material.
• Phong Nugyen, instructor
MESOPOROUS ZEOLITE-TYPE MATERIALS
The uniqueness of surfactant templated materials allows a variety of metal oxides to be
formed with uniform honeycomb structure and surface area approaching 1000 m2/g.
Surfactant templated materials have already been synthesized by the authors These
materials were synthesized with Mg, Cr, Ru, Pt, and Co doped in the MCM-41 silica
oxide.
FIGURE 7.
TEM of MCM-41 synthesized by the author
Synthesis of large Scale Mesoporous Substrates
(A) 60Å,
(B) 89 Å,
(C) 200 Å, (D)
260 Å.
FIGURE 8: TEM of mesoporous silica with different average pores
sizes
Synthesis of Organic and
Carbon Xerogels
• Resorcinol is a molecule that much like TEOS can
undergo hydrolysis and condensation reaction to
form a gel structure that can be dry as a xerogel or
aerogel.
• This gel can be further transformed in to a high
surface area carbon material. It gives the highest
capacitance per unit volume .
• Laurent Moch will demonstrate.
Synthesis of Silver NanoWires
• Particles are templated into a cylindrical
shape using a polymer.
• Martina Dreyer.
Synthesis of Silver NanoWires
NANOSTRUCTURED ANODIZED ALUMINUM
Anodized aluminum is an ideal substrate in that it possesses vertical
pores perpendicular to its surface.These nanopores are formed by
electrochemical etching and pore diameter can be precisely controlled
from 300 nm down to 2nm.
Figure 5: Anodized Alunminum
Figure 6: Diagram for using anodized aluminum to synthesize carbon nanotubes
Reactors CVD Synthesis of SWNTs
•Two parallel thermal reactors capable have already been constructed and tested,
•These carbon nanotube reactors can operate from 100 torr to above atmospheric
•The reactor’s temperature is computer controlled and may be ramped.
•The reactors are set up to run either in parallel or separately
•One of the reactors can handle large substrates such as silicon wafers up to 6
inches.
FIGURE 4:
Laboratory
Nanotube Reactor for CVD Synthesis of Carbon Nanobes in Our
(II) CARBON NANOTUBES
Below is pictured a diagram of the unique geometry of a carbon nanotube as well as a transmission electron
micrograph of a single wall nanotube produced in our department.
FIGURE 2:
Open Nanotube (Newman)
At 100-150 times the strength of steel yet only 1/60th of its weight, nanotubes are being recognized as the
penultimate fiber with a promise for material technology far surpassing all previous fibers yet created. This promise,
as noted, is far beyond just the properties obtained with carbon fibers, now used in the highest performance
composites. Potentially, future airplanes formed from
CARBON NANOTUBE
TEM OF NANOTUBE
FIGURE 3: Nanostructure and TEM of single wall nanotube as synthisized