TY  - JOUR
A1  - Micciulla, Samantha
A1  - Dodoo, Samuel
A1  - Chevigny, Chloe
A1  - Laschewsky, André
A1  - von Klitzing, Regine
T1  - Short versus long chain polyelectrolyte multilayers: a direct comparison of self-assembly and structural properties
JF  - Physical chemistry, chemical physics : a journal of European Chemical Societies
N2  - Successful layer-by-layer (LbL) growth of short chain (similar to 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 toss 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.
Y1  - 2014
U6  - https://doi.org/10.1039/c4cp03439b
SN  - 1463-9076
SN  - 1463-9084
VL  - 16
IS  - 40
SP  - 21988
EP  - 21998
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  -