often by electrostatic or van der Waals forces. SAMs can also result
through chemisorption.
Self-assembly: The process whereby molecules in the bulk phase
spontaneously organize either in the bulk phase or on a surface.
Semiconductor: A material with properties between an insulator and a
conductor, in which the energy difference between the highest
occupied state in the valence band (HOMO) and the lowest
unoccupied state in the conduction band (LUMO) is small.
Semiconductors can conduct electricity under certain conditions
and absorb visible light at some wavelengths.
Sigma bonding (s bonding): A strong covalent bond characterized by
symmetry with respect to rotation about the bond axis.
Small unilamellar vesicles (SUVs): Tiny (50−200 nm), single-walled
vesicles of uniform diameter.
Soft sphere model: More realistic way of modeling an atom, this model
assumes atoms are compressible to some degree and do not have
completely rigid boundaries.
Solvatochromism: Shift in the wavelength of light absorbed or emitted
from a molecule or nanomaterial due to the polarity of the surrounding solvent having more or less favorable interactions with
the ground and excited states of a system. A solvatochromic shift
that reduces the energy of a transition is called a bathochromic
shift, and a shift that increases the energy of a transition is called a
hypsochromic shift.
Spectroscopy: The study of the absorption of transmission of light
through a medium as a function of either wavelength or frequency.
Spot density: Number of spots that can be placed in a given area of a
DNA microarray, which varies greatly among in situ, noncontact,
and contact printing methods.
State function: A function that depends only on the initial and final
values of the function regardless of path taken. Temperature and
Gibbs energy are examples of state functions.
Steady-state approximation: An approximation in multistep reactions
where the concentration of an intermediate remains constant due
to it being produced and consumed at the same rate.
Glossary
455
through chemisorption.
Self-assembly: The process whereby molecules in the bulk phase
spontaneously organize either in the bulk phase or on a surface.
Semiconductor: A material with properties between an insulator and a
conductor, in which the energy difference between the highest
occupied state in the valence band (HOMO) and the lowest
unoccupied state in the conduction band (LUMO) is small.
Semiconductors can conduct electricity under certain conditions
and absorb visible light at some wavelengths.
Sigma bonding (s bonding): A strong covalent bond characterized by
symmetry with respect to rotation about the bond axis.
Small unilamellar vesicles (SUVs): Tiny (50−200 nm), single-walled
vesicles of uniform diameter.
Soft sphere model: More realistic way of modeling an atom, this model
assumes atoms are compressible to some degree and do not have
completely rigid boundaries.
Solvatochromism: Shift in the wavelength of light absorbed or emitted
from a molecule or nanomaterial due to the polarity of the surrounding solvent having more or less favorable interactions with
the ground and excited states of a system. A solvatochromic shift
that reduces the energy of a transition is called a bathochromic
shift, and a shift that increases the energy of a transition is called a
hypsochromic shift.
Spectroscopy: The study of the absorption of transmission of light
through a medium as a function of either wavelength or frequency.
Spot density: Number of spots that can be placed in a given area of a
DNA microarray, which varies greatly among in situ, noncontact,
and contact printing methods.
State function: A function that depends only on the initial and final
values of the function regardless of path taken. Temperature and
Gibbs energy are examples of state functions.
Steady-state approximation: An approximation in multistep reactions
where the concentration of an intermediate remains constant due
to it being produced and consumed at the same rate.
Glossary
455