Ion Transport and Vibrational Spectra of Branched Polymer and Dendrimer Electrolytes

Abstract

Solid electrolytes were prepared by the introduction of Li[(CF 3 SO 2 ) 2 N] into amorphous branched polymers and dendritic macromolecular hosts. These materials exhibit high ionic conductivity, but high concentrations of salt increase the glass transition temperatures, with an attendant decrease in ionic conductivity.

Dynamics of counterions in dendrimer polyelectrolyte solutions

“…Dynamics of these counterions, although referring to a rather low percentage of the total population, may be important in applications where ion transport is desired to be carefully controlled. 64,66 As has been demonstrated in our analysis of Van Hove functions in the latter regime, the time scale at which populations with noticeably different mobilities appear, as well as the time scale for relaxation of local counterion density fluctuations, is much shorter compared to the residence times of the strongly bound counterions. This information, combined with the structural details concerning the arrangement of counterions ͑either around the charged dendrimer beads or around other counterions͒, indicated that the dynamic features observed in the distinct and the self-part of the Van Hove functions were mainly related to the population of counterions loosely bound to the dendrimers and to the exchange mechanism between them and the condensed population, respectively.…”

“…This motional coupling between condensed counterions and dendrimers in the strong Coulombic regime was consistent with the manifestation of a dynamic transition in the survival ͑residence͒ times of the pairs formed between counterions and dendrimer charged beads, much in analogy to the observed coupling between counterions and long length scale dynamic modes in other macromolecular electrolyte systems. 10,30,64,65 In the weak electrostatic regime where the majority of counterions are only loosely associated with the charged dendrimer beads, the relevant residence time scale is much shorter; in this regime these counterions can be visualized to perform an oscillatory motion along the direction of loose virtual bonds connecting them with the charged dendrimer beads, in a fashion similar to the motion characterized as the "high frequency" process in dielectric relaxation experiments performed in polyelectrolyte solutions. 32 This process appears to be coupled to global dendrimer motion as well, most probably through the dendrimer rotational relaxation.…”

Organic/inorganic hybrid nanospheres based on hyperbranched poly(ethylene imine) encapsulated into silica for the sorption of toxic metal ions and polycyclic aromatic hydrocarbons from water

“…bands can hardly be detected in the hybrid PEI-silica particles' spectrum. The band of N-H asymmetric stretching is hardly observed at 3350 cm −1 while the symmetric and asymmetric stretching bands of CH 2 appear at 2962 and 2922, 2853 cm −1 [27]. These bands are shifted to higher wavelengths compared to the same bands registered for PEI (2930 and 2285, 2807 cm −1 respectively).…”

Radically crosslinked branched poly(N-allylethylenimine) with lithium triflate as a solid state polymer electrolyte

“…A maximum conductivity of 10 K6 S/cm at 20 8C has been reported for BPEI:LiTf at a 20:1 (N:Li C ) composition [7,8]. Chemically modified BPEI-type dendrimers, poly(propyleneimine) tetrahexacontaamine (DAB-AM-64) and poly(amidoamine) (PAMAM), have been reported by Dillon et al [9]. The optimum conductivity of complexes formed by these dendrimers and Li[(CF 3 SO 2 ) 2 N] ranges from 6.3!10 K7 S/cm at room temperature to 1.0!10 K4 S/cm at 100 8C [9].…”

“…Chemically modified BPEI-type dendrimers, poly(propyleneimine) tetrahexacontaamine (DAB-AM-64) and poly(amidoamine) (PAMAM), have been reported by Dillon et al [9]. The optimum conductivity of complexes formed by these dendrimers and Li[(CF 3 SO 2 ) 2 N] ranges from 6.3!10 K7 S/cm at room temperature to 1.0!10 K4 S/cm at 100 8C [9]. Attempts have been made to improve the physical properties of PEI by chemical modification of the backbone nitrogen atoms [10,11].…”