Polyelectrolyte Dendrimers

Montano GA, Dattelbaum AM, Wang H-L, Shreve AP (2004) Enhanced photoluminescence from poly(phenylene vinylene) dendrimer polyelectrolyte assemblies in solution. Chem Commun 2490-2491... 

Assembly and mechanical properties of phosphorus dendrimer/polyelectrolyte multilayer microcapsules. Langmuir 21 7200-7206... 

Anionic PAMAM dendrimers, 26 798 Anionic polyCacrylic acid), 20 465, 466 Anionic polyelectrolytes, 20 465-469 Anionic polymerization, 24 244 19 836 ... 

The hyperbranched poly( acrylic acid) graft films -C02H-rich interface on polyethylene can be modified by noncovalent methods just like CO2H-rich interfaces of PAA/Au grafts. This was shown by treating deprotonated 3-PAA/PE films with cationic polyelectrolytes like poly-D-lysine, and amine terminated PAMAM dendrimers at pH 7 [31]. Equation 10 illustrates the entrapment of PAMAM dendrimers in a 3-poly(sodium acrylate)/PE film. In these cases, polyvalent entrapment of the cationic electrolyte was evidenced in the ATR-IR spectriun by the appearance of amide C = O and N - H peaks of the guest dendrimer that were not present in the host 3-poly(sodium acrylate)/PE film. 

Giupponi G, Buzza DMA, Adolf DB. Are polyelectrolyte dendrimers stimuli responsive Macromolecules 2007 40 5959-5965. 

Miura N, Dubin PL, Mooiefield CN, Newkome GR. Complex formation by electrostatic interaction between carboxyl-terminated dendrimers and oppositely charged polyelectrolytes. Langmuir 1999 15 4245-4250. 

PAMAM dendrimer in methanol[19], and larger also than the 60 A maximum physical radius of a completely stretched structure, but has been employed consistently. In terms of the model, some of the scatter in Figure 4 can be explained by considering that the radius of gyration of this polyelectrolyte is likely to depend on the ionic strength, pH, and even the concentration of borate diesters (internal cycles) none of these factors were systematically controlled in this study. 

Some data have also appeared for the first five generations of the smaller DAB(CN)X and DAB(NH2)X dendrimers (see Scheme 1 for structure). For DAB(CN)X in acetone-d6 SANS yields v=0.31 (generations 2-5). For DAB(NH2)X in D20 the low MW dendrimers follow Rg M0-30 [71]. In general, it is difficult to determine Rg of low MW dendrimers accurately [70]. Furthermore, all dendrimers studied have ionizable groups and may act like polyelectrolytes. Therefore solvent conditions need to be carefully controlled and specified. 

NaPGA) and amine-terminated PAMAM dendrimers [102-105], The flexible NaPGAs are possible to interact not only with protonated primary amines in the periphery of a dendrimer but also with tertiary amines in its interior. Opposite combination of the complex, which is stimulated by the electrostatic interaction, was formed between cationic synthetic polyelectrolyte, poly(dial-lyldimethylammonium chloride), and anionic carboxyl-terminated PAMAM dendrimers [106-109],... 

Fig. 5. (Left) SEIRAS of NaHA and DNA on PAMAM dendrimer SAMs after adsorption for 30 min from aqueous solutions. Dendrimer SAMs were prepared by the amide bond formation of dendrimers with active ester groups of 3-mercapto-propionic acid (MPA) SAMs on CaF2 substrates. Infrared absorption spectra of NaHA, DNA, and PAMAM dendrimer are also included. (Right) Schematic illustration of the interactions between polyelectrolytes and dendrimer SAMs. Reprinted from Ref. [110].

Desorption reaction in water at different pHs on polyelectrolyte-adsorbed PAMAM dendrimer SAM substrates was followed up with SEIRAS (Fig. 7) [24, 110]. The characteristic amide I and II bands of NaPGA, a C-OH band of NaHA and DNA, and a P=0 band of DNA decrease with increasing pH of immersion water. The desorption is almost done within initial 30 min but proceeds slowly with time till overnight and, in all cases, the desorption reaction runs down, when the adsorbed molecules decrease down to the amount adsorbed at each pH. Namely, it can be remarked that the adsorption/desorption processes are reversible. Moreover, the present dendrimer SAMs have an advantage to be reusable for the adsorption/desorption reactions. In the case of the desorption reaction at pH 9.08 on a DNA-adsorbed PAMAM dendrimer SAM substrates, DNA on a substrate prepared at pH 3.04 does not achieve the adsorption amount at the adsorption reaction at the same pH, owing to the... 

Fig. 6. Time dependence of film thicknesses of polyelectrolytes adsorbed on dendrimer SAMs. Concentrations of polyelectrolytes are 0.04wt.% for NaPGA and NaHA and 0.02wt.% for DNA. Numerical values in blankets after pH values denote the film thicknesses at absorption equilibrium. Reprinted from Ref. [111].

---