**Nanostructured Materials by Self-Assembly and Sol-Gel Process**

Y. Lu

Abstract Number: **Lu135**

**Introduction**: Advances in materials science have fueled revolutions
in technology we enjoy today. Increasingly, the emphasis has been placed
on smaller scales that have greater functionality. Nanomaterials have
thus become one of the most active and promising research areas. To
date, many efforts have been concentrated on synthesis and
characterization of nanomaterials; however, the development of simple,
ready and efficient approaches that lead to flexible and affordable
syntheses of nanomaterials still remains as a challenge. This
presentation addresses a general self-assembly approach to efficiently
fabricate silica-based nanostructured thin films and particles flexibly
and affordably, employing methods of evaporation induced self-assembly
(EISA) to spatially organize inorganic and organic materials into two-
or three-dimensional nanostructures during conventional liquid coating
or aerosol processing.

**Methods and Materials**: The experimental procedure start with
homogenous solution of soluble silica and surfactant prepared in an
ethanol/water solvent. Preferential evaporation of ethanol during the
coating or aerosol processes results in self-assembly of surfactants
into micelles and further self-organization of micelles into liquid
crystal mesophases that organize the soluble silica around their
hydrophilic exteriors. Polymerization of silicate followed by surfactant
removal results in nanoporous thin films or particles with uniform pore
sizes and controlled pore structures. During the self-assembly process,
hydrophobic components, including functionalized polymers and monomers,
organic ligands, dyes, catalyst particles, and metal colloids, can be
spontaneously and spatially incorporated into the hydrophobic micellar
interiors, resulting in formation of ordered nanocomposited materials
upon further liquid crystalline assembly. This approach has been
extended to prepare patterned functional hierarchically organized
structures using three rapid printing procedures (pen-lithography,
ink-jet printing, and dip-coating of patterned self-assembly monolayer).

The beauty of this approach is its simplicity and efficiency. It
provides an excellent approach to synthesize both functionalized and
non-functionlized nanostructured thin films and particles, which are
important for membrane, separation, adsorbent, sensor, catalyst, filler,
controlled release, and other applications.

**References**: (1) Lu, Y.; Yang, Y.; Sellinger, A.; Lu, M.; Huang, J.;
Fan, H.; Haddad, R.; Lopez, G.; Burns, A.; R.; Sasaki, D.; Shelnutt, J.;
Brinker, C. J. "Self-assembly of mesoscopically ordered chromatic
polydiacetylene/silica nanocomposites" *Nature*, **410**, 913-917, 2001.
(2) Fan, H.; Lu, Y.; Stump, A.; Reed, S. T.; Baer, T.; Schunk, R.;
Perez-Luna, V.; López, G. P.; Brinker, C. J. "Rapid Prototyping of
Patterned Functional Nanostructures," *Nature*, **405**, 56-60, 2000.
(3) Lu, Y.; Fan, H.; Stump, A.; Ward, T. L.; Reiker, T.; Brinker, C. J.
"Aerosol-Assisted Self-Assembly of Mesostructured Spherical
Nanoparticles," *Nature, 398*, 223, 1999. (3) Lu, Y.; Ganguli, R.;
Drewien, C. A.; Anderson, M. T.; Brinker, C. J.; Gong, W.; Guo, Y.;
Soyez, H.; Dunn, B.; Huang, M. H.; Zink, J. I. "Continuous Formation of
Supported Cubic and Hexagonal Mesoporous Films by Sol-Gel Dip-Coating,"
*Nature,* ***389***, 364-368, 1997.