Summary of Molecular Dynamics Simulations of
Charged Polymers
Summary:
1. Polyampholytes take the forms of condensed globules and random
coils at low and high temperatures, respectively. (Room temperature
is between them.) The volume change path is single valued under
the Coulomb forces, which becomes double valued and hysteresis
appears when short-range attraction forces coexist.
2. Loosely-connected polyampholytes crystallize to a bcc crystal at
very low temperatures, because electrostatic repulsion inhibits the
crystallization to fcc. Usual polyampholytes end up with amorphous.
3. Upon increase in salt ionic strength for constant temperature,
nonneutral polyampholytes show reentrant behavior, first collapsing
to neutral polyampholyte state, then expanding to noncharged polymer
state. The polyampholyte volume becomes minimum when the
salt ionic strength is the same as that of polyampholytes.
References：
Structure of polyampholytes, occurrence of hysteresis
Phys.Rev. E56, p.5798-5808 (1997).
Multichain polyampholytes and added salt
J.Chem.Phys.110, p.8176-8188 (1999).
Coulomb crystallization to bcc of polyampholytes, and
the effect of salt
Phys.Rev. E62, p.3803-3816 (2000).
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Charged Polymers
Summary:
1. Polyampholytes take the forms of condensed globules and random
coils at low and high temperatures, respectively. (Room temperature
is between them.) The volume change path is single valued under
the Coulomb forces, which becomes double valued and hysteresis
appears when short-range attraction forces coexist.
2. Loosely-connected polyampholytes crystallize to a bcc crystal at
very low temperatures, because electrostatic repulsion inhibits the
crystallization to fcc. Usual polyampholytes end up with amorphous.
3. Upon increase in salt ionic strength for constant temperature,
nonneutral polyampholytes show reentrant behavior, first collapsing
to neutral polyampholyte state, then expanding to noncharged polymer
state. The polyampholyte volume becomes minimum when the
salt ionic strength is the same as that of polyampholytes.
References：
Structure of polyampholytes, occurrence of hysteresis
Phys.Rev. E56, p.5798-5808 (1997).
Multichain polyampholytes and added salt
J.Chem.Phys.110, p.8176-8188 (1999).
Coulomb crystallization to bcc of polyampholytes, and
the effect of salt
Phys.Rev. E62, p.3803-3816 (2000).
Previous Page
Home