Precise building blocks
can be selected and organized into useful structures by using surface modifications or specialized surfactant additives.
To overcome these shortcomings, he and his colleagues start with siloxane building blocks
that contain fluorine atoms.
By kicking off some or all of these side groups while joining the building blocks
and by varying the ratio of monomers, they adjust the degree and spacing of conjugation, and consequently the color of light emitted.
Starting with molecular building blocks
of their own design, the researchers are learning to precisely and rationally control how these blocks organize into crystal structures and macroscopic solid materials.
In fact, he says, new experimental data from his laboratory suggest that the formation and linking of life's building blocks
-- amino acids and nucleotides -- may have been all but inevitable, given the starting chemistry of earth's "primordial soup.