Naslov
Conditions Leading to Polyelectrolyte Complex Overcharging in Solution: Complexation of Poly(acrylate) Anion with Poly(allylammonium) Cation

Autori
Kremer, Tomislav ; Kovačević, Davor ; Salopek, Jasmina ; Požar, Josip

Izvornik
Macromolecules (0024-9297) 49 (2016), 22; 8672-8685

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
overcharging ; polyelectrolyte complexes ; poly(acrylate) anion ; poly(allylammonium) cation ; electrokinetics ; dynamic light scattering ; microcalorimetry

Sažetak
Complexation between poly(acrylate) (PA) and poly(allylammonium) (PAH) macroions at pH = 7.0 was studied by means of electrokinetics, microcalorimetry and DLS. At low polyelectrolyte concentrations and no electrolyte present strong overcharging of primary nanocomplexes occurred. In contrast, the increase in polyelectrolyte concentration led to flocculation taking place near the equivalence. The nanocomplex charge reversal was also achieved in the high polymer concentration regime by the abrupt instead of stepwise titrant addition. The procedure was successfully used in the case of several other polyion pairs. The presence of electrolyte affected the PAH-PA interpolyelectrolyte neutralization considerably, leading to ion- specific aggregation and extrinsic charge compensation. The complexation energetics was weakly influenced by ionic conditions. To the best of our knowledge, the reported results are the first direct evidence for primary complex overcharging. Their rationalization explains why interpolyelectrolyte neutralization in solution and at surfaces usually results with formation of neutral and charged products respectively.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA