TY - JOUR
T1 - Salt Sensitivity of the Thermoresponsive Behavior of PNIPAAm Brushes
AU - Koenig, Meike
AU - Rodenhausen, Keith Brian
AU - Rauch, Sebastian
AU - Bittrich, Eva
AU - Eichhorn, Klaus Jochen
AU - Schubert, Mathias
AU - Stamm, Manfred
AU - Uhlmann, Petra
N1 - Funding Information:
Financial support was granted by the German Science Foundation (DFG) within the DFG-NSF cooperation project (DFG Proj. Nr. STA 324/49-1 and EI 317/6-1) in the frame of the “Materials World Network” and in the frame of the priority program SPP 1369 “Polymer-Solid Contacts: Interfaces and Interphases” (DFG Proj. Nr. STA 324/37-1). This work was supported in part by the National Science Foundation (NSF) through the Center for Nanohybrid Functional Materials (EPS-1004094).
Funding Information:
Financial support was granted by the German Science Foundation (DFG) within the DFG-NSF cooperation project (DFG Proj. Nr. STA 324/49-1 and EI 317/6-1) in the frame of the Materials World Network and in the frame of the priority program SPP 1369 Polymer-Solid Contacts: Interfaces and Interphases (DFG Proj. Nr. STA 324/37-1). This work was supported in part by the National Science Foundation (NSF) through the Center for Nanohybrid Functional Materials (EPS-1004094).
PY - 2018/2/20
Y1 - 2018/2/20
N2 - We report investigations on the salt sensitivity of the thermoresponsive behavior of PNIPAAm brushes applying the quartz crystal microbalance coupled with spectroscopic ellipsometry technique. This approach enables a detailed study of the optical and mechanical behavior of the polymer coatings. Additional conclusions can be drawn from the difference between both techniques due to a difference in the contrast mechanism of both methods. A linear shift of the phase-transition temperature to lower temperatures with the addition of sodium chloride was found, similar to the behavior of free polymer chains in solution. The thermal hysteresis was found to be decreased by the addition of sodium chloride to the solution, hinting to the interaction of the ions with the amide groups of the polymer, whereby the formation of hydrogen bonds is hindered. The results of this study are of relevance to the application of PNIPAAm brushes in biological fluids and demonstrate the additional potential of the ion sensitivity besides the better known thermosensitivity.
AB - We report investigations on the salt sensitivity of the thermoresponsive behavior of PNIPAAm brushes applying the quartz crystal microbalance coupled with spectroscopic ellipsometry technique. This approach enables a detailed study of the optical and mechanical behavior of the polymer coatings. Additional conclusions can be drawn from the difference between both techniques due to a difference in the contrast mechanism of both methods. A linear shift of the phase-transition temperature to lower temperatures with the addition of sodium chloride was found, similar to the behavior of free polymer chains in solution. The thermal hysteresis was found to be decreased by the addition of sodium chloride to the solution, hinting to the interaction of the ions with the amide groups of the polymer, whereby the formation of hydrogen bonds is hindered. The results of this study are of relevance to the application of PNIPAAm brushes in biological fluids and demonstrate the additional potential of the ion sensitivity besides the better known thermosensitivity.
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U2 - 10.1021/acs.langmuir.7b03919
DO - 10.1021/acs.langmuir.7b03919
M3 - Article
C2 - 29356537
AN - SCOPUS:85042265967
VL - 34
SP - 2448
EP - 2454
JO - Langmuir
JF - Langmuir
SN - 0743-7463
IS - 7
ER -