Ordered Inorganic-Organic Composites & Porous Solids:

Interdisciplinary Materials Science & Engineering Opportunities

Dr. Brad ChmelkaDepartment of Chemical Engineering

University of CaliforniaSanta Barbara, CA 93106

Cal Poly, San Luis Obispo, January 23, 2002

Biominerals: Strong natural structural materials

T. Schäffer et al., Chem. Mater. 9, 1731 (1997) Scanning electron micrograph

• Oriented single crystals of CaCO3

• Shell exterior: 99% calcite 1% organic

1000 times stronger than polycrystalline CaCO3

• Interior nacre: 99% aragonite 1% organic

mother-of-pearl

Abalone shell: Protein-directed crystallization

Self-Assembled Inorganic-Organic

Materials

Nanoscopic, 10-9 m

Mesoscopic

Microscopic, 10-6 m

Macroscopic

New Technology Opportunities & Applications

Functionalized Porous Powders and Fibers

catalysts, separation & filtration media, adsorbents

Films and Coatings

functional membranes, barriers, packaging, fuel cells

Electronic Materials

low-dielectric-constant films and monoliths

Optical Materials

lasers, waveguides, optical limiters, optical interconnects,

photonic crystals

Sensors

chemical and biosensors

SBA-15

20 nm 20 nm

30 nm 25 nm

4.7 nm 6.0 nm

20.0 nm 26.0 nm

D. Zhao et al., Science, 279, 548 (1998)P. Yang et al., Nature, 396, 152 (1998)

SiAlO3.5

Si2AlO5.5

Al2TiO5

ZrTiO4

SiTiO4

ZrW2O8

ZrO2

TiO2

Nb2O5

Ta2O5

WO3

SnO2

HfO2

Al2O3

SiO2

Ge2O3

V2O5 ZnOx

CdOx

InOx

SbOx

MoOx

ReOx

NiOx

MnOx

CrOx

CuOx

• Non-oxidic systems

• Semiconductors

Hexagonal SBA-15: uniform, tunable mesoporous oxide arrays

50 nm

Incorporation of Optical Functionalities

• Organic Dyes

• Conjugated Polymers

• Organometallics

• DNA

• Semiconducting Quantum Dots

• Nanowires

• Inorganic Charge Transfer

• Rare Earth Complexes

• Enzymes, e.g., organophosphorus

hydrolase

N NO2O

In transparent mesoporous solids

In transparent composites