Summary of Molecular Dynamics Simulations of Charged Polymers 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 (1997). 　　　Multichain polyampholytes and added salt 　　　　　　J.Chem.Phys.110 (1999). 　　　Coulomb crystallization to bcc of polyampholytes, and 　　　the effect of salt 　 　　　　　　Phys.Rev. E62 (2000). 　Previous Page 　　Home