The Effect of Temperature Treatment on the Structure of Polyelectrolyte Multilayers
نویسندگان
چکیده
The study addresses the effect of thermal treatment on the internal structure of polyelectrolyte multilayers (PEMs). In order to get insight into the internal structure of PEMs, Neutron Reflectometry (NR) was used. PEMs with a deuterated inner block towards the substrate and a non-deuterated outer block were prepared and measured in 1% RH and in D2O before and after a thermal treatment. Complementarily, PEMs with the same number of layers but completely non-deuterated were investigated by ellipsometry. The analysis for the overall thickness (d), the average scattering length density (SLD) and the refractive index (n) indicate a degradation of the PEM. The loss in material is independent of the number of layers, i.e., only a constant part of the PEM is affected by degradation. The analysis of the internal structure revealed a more complex influence of thermal treatment on PEM structure. Only the outermost part of the PEM degenerates, while the inner part becomes denser during the thermal treatment. In addition, the swelling behavior of PEMs is influenced by the thermal treatment. The untreated PEM shows a well pronounced odd—even effect, i.e., PDADMAC-terminated PEMs take up more water than PSS-terminated PEMs. After the thermal treatment, the odd-even effect becomes much weaker.
منابع مشابه
Polyelectrolyte Multilayers on Magnetic Silica as a New Sorbent for the Separation of Trace Silver in the Leaching Solutions of Antibacterial Products and Determination by Flame Atomic Absorption Spectrometry
A novel, magnetic silica sorbent with polyelectrolyte multilayers (PEMs) on its surface was prepared, and was used for Magnetic Solid Phase Extraction (MSPE) of trace A+ via Flame Atomic Absorption Spectrometry (FAAS). The experimental parameters for the MSPE procedure, such as the pH, type, and concentration of eluent, ultrasonic time and effects of co-existing ions wer...
متن کاملMagnetic Properties and Structural Study of Ni-Co/Cu Multilayers Prepared by Electrodeposition Method
Ni-Co/Cu multilayers have been grown by electrodeposition method from a single electrolyte (based on Ni(SO4).6H2O, Co(SO4).7H2O, Cu(SO4) and H3BO3) using galvanostatic control on titanium sublayers. The X-ray diffraction (XRD) patterns confirmed the multilayered structure with the nanometer thicknesses. Also, electron diffraction x-ray (EDX) analysis confirmed the purity of deposited samples. ...
متن کاملEffect of the hydrothermal treatment, HCl purification and annealing temperature on the structure and the morphology of TiO2 nanotubes
متن کامل
Temperature effect on the build-up of exponentially growing polyelectrolyte multilayers. An exponential-to-linear transition point.
In this study, the effect of temperature on the build-up of exponentially growing polyelectrolyte multilayer films was investigated. It aims at understanding the multilayer growth mechanism as crucially important for the fabrication of tailor-made multilayer films. Model poly(L-lysine)/hyaluronic acid (PLL/HA) multilayers were assembled in the temperature range of 25-85 °C by layer-by-layer dep...
متن کاملTemperature responsive behavior of polymer brush/polyelectrolyte multilayer composites.
The complex interaction of polyelectrolyte multilayers (PEMs) physisorbed onto end-grafted polymer brushes with focus on the temperature-responsive behavior of the system is addressed in this work. The investigated brush/multilayer composite consists of a poly(styrene sulfonate)/poly(diallyldimethylammonium chloride) (PSS/PDADMAC) multilayer deposited onto the poly(N-isopropylacrylamide-b-dimet...
متن کامل