کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1233664 | 968814 | 2010 | 8 صفحه PDF | دانلود رایگان |
The preparation and spectroscopic and microscopic characterization of oriented polyelectrolyte multilayers (PEM) interesting for defined nanostructured functional materials and surfaces are reviewed. Oriented PEM were generated by consecutively adsorbing α-helical poly(l-lysine) (PLL) and oppositely charged polyanions like poly(vinylsulfate) (PVS) or poly(styrene sulfonate) (PSS) at silicon substrates texturized by parallel nanoscopic surface grooves, respectively. Dichroic Attenuated Total Reflexion Fourier Transform Infrared (ATR-FTIR) spectroscopy was used to study the conformation and macromolecular order of stiff polyelectrolytes within PEM. High order parameters up to S = 0.82 (S = 1 for high, S = 0 for low order) were obtained from the dichroic ratios of the Amide I and Amide II bands suggesting a significant alignment of charged α-helical polypeptides in PEM. For PEM consisting of PLL/polyanion the S values significantly increased with increasing molecular weight of PLL and with decreasing molecular weight of the polyanion. These spectroscopic findings were supported by SFM images on PEM-PLL/PVS with high molecular PLL and PEM-PLL/PSS with low molecular PSS, which both showed anisotropically oriented worm-like structures, while PEM-PLL/PVS with low molecular PLL and PEM-PLL/PSS with high molecular PSS showed no orientation features.
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 77, Issue 4, November 2010, Pages 709–716