direkt zum Inhalt springen

direkt zum Hauptnavigationsmenü

Sie sind hier

TU Berlin

Inhalt des Dokuments

after 2006

Short versus long chain polyelectrolyte multilayers: a direct comparison of self-assembly and structural properties
Zitatschlüssel micc14a
Autor Micciula, S. and Dodoo, S. and Chevigny, C. and Laschewsky, A. and von Klitzing, R.
Seiten 21988-21998
Jahr 2014
DOI 10.1039/c4cp03439b
Journal Phys. Chem. Chem. Phys.
Jahrgang 16
Zusammenfassung Successful layer-by-layer (LbL) growth of short chain ( 30 repeat units per chain) poly(sodium styrene sulfonate) (PSS)–poly(diallyl dimethylammonium chloride) (PDADMAC) multilayers is presented for the first time and compared with the growth of equivalent long chain polyelectrolyte multilayers (PEMs). A detailed study performed by quartz crystal microbalance with dissipation (QCM-D) is carried out and three main processes are identified: (i) initial mass uptake, (ii) adsorption–desorption during layer equilibration and (iii) desorption during rinsing. In contrast to the high stability and strong layer increment of high molecular weight (HMW) PEMs, layer degradation characterizes low molecular weight (LMW) multilayers. In particular, two different instability phenomena are observed: a constant decrease of sensed mass during equilibration after PDADMAC adsorption, and a strong mass loss by salt-free rinsing after PSS adsorption. Yet, an increase of salt concentration leads to much stronger layer growth. First, when the rinsing medium is changed from pure water to 0.1 M NaCl, the mass loss during rinsing is reduced, irrespective of molecular weight. Second, an increase in salt concentration in the LMW PE solutions causes a larger increment during the initial adsorption step, with no effect on the rinsing. Finally, the mechanical properties of the two systems are extracted from the measured frequency and dissipation shifts, as they offer a deeper insight into the multilayer structures depending on chain length and outermost layer. The paper enriches the field of PE assembly by presenting the use of very short PE chains to form multilayers and elucidates the role of preparation conditions to overcome the limitation of layer stability.
Link zur Originalpublikation Download Bibtex Eintrag

Zusatzinformationen / Extras