scholarly journals Porous Ultra-Thin Films from Photocleavable Block Copolymers: In-Situ Degradation Kinetics Study of Pore Material

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 781 ◽  
Author(s):  
Sedakat Altinpinar ◽  
Wael Ali ◽  
Patrick Schuchardt ◽  
Pinar Yildiz ◽  
Hui Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Polymer Film ◽  
Uv Exposure ◽  
Significant Information ◽  
X Ray ◽  
Washing Process

On the basis of the major application for block copolymers to use them as separation membranes, lithographic mask, and as templates, the preparation of highly oriented nanoporous thin films requires the selective removal of the minor phase from the pores. In the scope of this study, thin film of polystyrene-block-poly(ethylene oxide) block copolymer with a photocleavable junction groups based on ortho-nitrobenzylester (ONB) (PS-hν-PEO) was papered via the spin coating technique followed by solvent annealing to obtain highly-ordered cylindrical domains. The polymer blocks are cleaved by means of a mild UV exposure and then the pore material is washed out of the polymer film by ultra-pure water resulting in arrays of nanoporous thin films to remove one block. The removal of the PEO materials from the pores was proven using the grazing-incidence small-angle X-ray scattering (GISAXS) technique. The treatment of the polymer film during the washing process was observed in real time after two different UV exposure time (1 and 4 h) in order to draw conclusions regarding the dynamics of the removal process. In-situ X-ray reflectivity measurements provide statistically significant information about the change in the layer thickness as well as the roughness and electron density of the polymer film during pore formation. 4 H UV exposure was found to be more efficient for PEO cleavage. By in-situ SFM measurements, the structure of the ultra-thin block copolymer films was also analysed and, thus, the kinetics of the washing process was elaborated. The results from both measurements confirmed that the washing procedure induces irreversible change in morphology to the surface of the thin film.

An In Situ Grazing Incidence X-Ray Scattering Study of Block Copolymer Thin Films During Solvent Vapor Annealing

2013 ◽  
Vol 26 (2) ◽  
pp. 273-281 ◽  
Author(s):  
Xiaodan Gu ◽  
Ilja Gunkel ◽  
Alexander Hexemer ◽  
Weiyin Gu ◽  
Thomas P. Russell
Keyword(s):  
Thin Films ◽  
Block Copolymer ◽  
Grazing Incidence ◽  
Solvent Vapor ◽  
X Ray ◽  
X Ray Scattering ◽  
Vapor Annealing ◽  
Scattering Study ◽  
Solvent Vapor Annealing

Sensing of Ethanol with Nanosize FeZnO Thin Films

2008 ◽  
Vol 47-50 ◽  
pp. 1117-1120
Author(s):  
G.H. Kuo ◽  
H. Paul Wang ◽  
H.H. Hsu ◽  
Chih Ju G. Jou ◽  
Y.M. Chiu ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
High Sensitivity ◽  
Zno Thin Films ◽  
X Ray ◽  
Doped Zno ◽  
Low Sensitivity ◽  
X Ray Absorption ◽  
Exafs Spectra

In the present work, sensing of ethanol on the ZnO thin films doped with Fe (5-50%) have been investigated. Nature of the sensing species in the nanosize Fe-doped ZnO (FeZnO) thin films has also been studied by in situ extended X-ray absorption fine structure (EXAFS) spectroscopy. By XRD, it is found that ZnO and ZnFe2O4 are the main compounds in the ZnO-Fe thin films. The thin film containing 5% of Fe has a high sensitivity (Rair/Rethanol>80) when sensing of ethanol at 300 K. On the contrary, the thin films with Fe fractions of 20-50% have a very low sensitivity to ethanol (Rair/Rethanol<15). In the presence of ethanol, the EXAFS spectra show that the bond distances of Zn-O and Fe-O in the thin films are 1.90 and 1.98 Å, respectively and restored to 1.91 and 1.97 Å in the absence of ethanol.

Crossover from semi-dilute to densely packed thin polymer films at the air–water interface and structure formation at thin film breakup

Soft Matter ◽  
2018 ◽  
Vol 14 (23) ◽  
pp. 4750-4761 ◽  
Author(s):  
Christian Appel ◽  
Martin Kraska ◽  
Christian Rüttiger ◽  
Markus Gallei ◽  
Bernd Stühn
Keyword(s):  
Thin Film ◽  
Polymer Film ◽  
Structure Formation ◽  
Water Interface ◽  
Thin Polymer Films ◽  
X Ray ◽  
X Ray Scattering ◽  
Thin Polymer ◽  
Air Water Interface

First evidence for thin film breakup of a polymer film observed by in situ Surface X-ray scattering at the air–water interface.

scholarly journals In-Situ Neutron Reflectometry on Polymer Thin Films in Different Environments

2014 ◽  
Vol 70 (a1) ◽  
pp. C880-C880
Author(s):  
Naoya Torikai
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Structural Change ◽  
Block Copolymer ◽  
Polymer Thin Films ◽  
Neutron Reflectometry ◽  
Proton Accelerator ◽  
Original Structure ◽  
Material Interfaces

Neutron reflectometry is indispensable for the studies on material interfaces and thin films, since it can probe the interfaces non-destructively with a quite high depth resolution. Here, the interfacial structures of polymer thin films in different environments: hot and wet, were examined by means of in-situ neutron reflectometry. The neutron reflectivity measurements were performed on a time-of-flight reflectometer SOFIA [1, 2] at the Japan Proton Accelerator Research Complex (J-PARC). The depth distribution of components was investigated for binary blend thin films of polystyrenes with different molecular weights to clarify the mechanism of de-wetting suppression effect by blending a small amount of the longer homologue. It was found by static measurements that the longer chains deplete from the air surface of the film, while they slightly localize at the interface with the substrate. The time evolution of the component distribution was also examined by in-situ measurements above the glass transition temperature in a vacuum. The structural change of lamellarly-ordered styrene-2-vinylpyridine (PS-P2VP) diblock copolymer thin film in contact with solvent was explored by in-situ neutron reflectometry with a conventional solid/liquid cell. During the block copolymer thin film was in contact with methanol, which is selective for P2VP, some of methanol penetrated into the film causing the structural change. However, the original structure was almost recovered after drying, though annealing effect was slightly observed. When toluene was made contact, which is selective for PS, the block copolymer thin film was immediately dissolved into, and never recovered.

Structural Analysis on a Block Copolymer Thin Film by In-situ Neutron and X-ray Grazing-incidence Scattering Techniques

hamon ◽  
2011 ◽  
Vol 21 (2) ◽  
pp. 91-95
Author(s):  
Naoya Torikai ◽  
Norifumi L. Yamada ◽  
Daisuke Kawaguchi
Keyword(s):  
Thin Film ◽  
Structural Analysis ◽  
Block Copolymer ◽  
Grazing Incidence ◽  
X Ray

scholarly journals In Situ X-ray Measurements to Follow the Crystallization of BaTiO3 Thin Films during RF-Magnetron Sputter Deposition

2021 ◽  
Vol 11 (19) ◽  
pp. 8970
Author(s):  
Peter Walter ◽  
Markus Ilchen ◽  
JanTorben Roeh ◽  
Wiebke Ohm ◽  
Christian Bonar Zeuthen ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Growth ◽  
Structural Evolution ◽  
Thin Film Growth ◽  
Structure Evolution ◽  
Special Focus ◽  
Time Resolved ◽  
X Ray

Here, we report on adding an important dimension to the fundamental understanding of the evolution of the thin film micro structure evolution. Thin films have gained broad attention in their applications for electro-optical devices, solar-cell technology, as well storage devices. Deep insights into fundamental functionalities can be realized via studying crystallization microstructure and formation processes of polycrystalline or epitaxial thin films. Besides the fundamental aspects, it is industrially important to minimize cost which intrinsically requires lower energy consumption at increasing performance which requires new approaches to thin film growth in general. Here, we present a state of the art sputtering technique that allows for time-resolved in situ studies of such thin film growth with a special focus on the crystallization via small angle scattering and X-ray diffraction. Focusing on the crystallization of the example material of BaTiO3, we demonstrate how a prototypical thin film forms and how detailed all phases of the structural evolution can be identified. The technique is shaped to enable a versatile approach for understanding and ultimately controlling a broad variety of growth processes, and more over it demonstrate how to in situ investigate the influence of single high temperature sputtering parameters on the film quality. It is shown that the whole evolution from nucleation, diffusion adsorption and grain growth to the crystallization can be observed during all stages of thin film growth as well as quantitatively as qualitatively. This can be used to optimize thin-film quality, efficiency and performance.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

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