scholarly journals Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

2016 ◽  
Vol 12 ◽  
pp. 2150-2163 ◽  
Author(s):  
Pierre Boufflet ◽  
Sebastian Wood ◽  
Jessica Wade ◽  
Zhuping Fei ◽  
Ji-Seon Kim ◽  
...  

The microstructure of the active blend layer has been shown to be a critically important factor in the performance of organic solar devices. Block copolymers provide a potentially interesting avenue for controlling this active layer microstructure in solar cell blends. Here we explore the impact of backbone fluorination in block copolymers of poly(3-octyl-4-fluorothiophene)s and poly(3-octylthiophene) (F-P3OT-b-P3OT). Two block co-polymers with varying block lengths were prepared via sequential monomer addition under Kumada catalyst transfer polymerisation (KCTP) conditions. We compare the behavior of the block copolymer to that of the corresponding homopolymer blends. In both types of system, we find the fluorinated segments tend to dominate the UV–visible absorption and molecular vibrational spectral features, as well as the thermal behavior. In the block copolymer case, non-fluorinated segments appear to slightly frustrate the aggregation of the more fluorinated block. However, in situ temperature dependent Raman spectroscopy shows that the intramolecular order is more thermally stable in the block copolymer than in the corresponding blend, suggesting that such materials may be interesting for enhanced thermal stability of organic photovoltaic active layers based on similar systems.

2014 ◽  
Vol 50 (80) ◽  
pp. 11919-11921 ◽  
Author(s):  
Iryna I. Perepichka ◽  
Mohamed A. Mezour ◽  
Dmitrii F. Perepichka ◽  
R. Bruce Lennox

Pyridine-containing block copolymers (PS-P4VP) can effectively stabilize metal nanoparticles which survive prolonged heating in solutions at high temperatures.


2013 ◽  
Author(s):  
Jr Morris ◽  
Shardo Robert W. ◽  
Higgins James ◽  
Cook Kim ◽  
Tanner Rhonda ◽  
...  

1993 ◽  
Vol 16 (5) ◽  
pp. 260-264 ◽  
Author(s):  
H.Y. Tong ◽  
B.Z. Ding ◽  
H.G. Jiang ◽  
Z.Q. Hu ◽  
L. Dong ◽  
...  

2007 ◽  
Vol 50 (3) ◽  
pp. 677 ◽  
Author(s):  
Jae-Wook Jae-Wook ◽  
Kyung-Hwan Kyung-Hwan ◽  
Hyoungsub Hyoungsub ◽  
Cheol-Woong Cheol-Woong ◽  
Dongwon Dongwon ◽  
...  

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 210
Author(s):  
Xiangdong Yang ◽  
Haitao Wang ◽  
Peng Wang ◽  
Xuxin Yang ◽  
Hongying Mao

Using in situ ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS) measurements, the thermal behavior of octadecyltrichlorosilane (OTS) and 1H, 1H, 2H, and 2H-perfluorooctyltriethoxysilane (PTES) monolayers on SiO2 substrates has been investigated. OTS is thermally stable up to 573 K with vacuum annealing, whereas PTES starts decomposing at a moderate temperature between 373 K and 423 K. Vacuum annealing results in the decomposition of CF3 and CF2 species rather than desorption of the entire PTES molecule. In addition, our UPS results reveal that the work function (WF)of OTS remains the same after annealing; however WF of PTES decreases from ~5.62 eV to ~5.16 eV after annealing at 573 K.


2003 ◽  
Vol 777 ◽  
Author(s):  
B.J. Inkson ◽  
G. Dehm

AbstractPt nanowires have been produced by FIB deposition of Pt thin films in a commercial Ga+ focused ion beam (FIB) system, followed by cross-sectional sputtering to form electron transparent Pt nanowires. The thermal stability of amorphous FIB manufactured Pt wires has been investigated by in-situ thermal cycling in a TEM. The Pt wires are stable up to 580-650°C where partial crystallization is observed in vacuum. Facetted nanoparticles grow on the wire surface, growing into free space by surface diffusion and minimising contact area with the underlying wire. The particles are fcc Pt with some dissolved Ga. Continued heating results in particle spheroidization, coalescence and growth, retaining the fcc structure.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 781 ◽  
Author(s):  
Sedakat Altinpinar ◽  
Wael Ali ◽  
Patrick Schuchardt ◽  
Pinar Yildiz ◽  
Hui Zhao ◽  
...  

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.


1990 ◽  
Vol 23 (6) ◽  
pp. 545-549 ◽  
Author(s):  
H. L. Bhat ◽  
S. M. Clark ◽  
A. El Korashy ◽  
K. J. Roberts

The design of a new microfurnace for use for Laue diffraction studies of solid-state transformations is described. The furnace operates in the temperature range 298–573 K with a thermal stability of about ± 0.1 K. The potential of the synchrotron-radiation Laue diffraction technique for studies of structural phase transitions is demonstrated. Experimental data on phase transitions in caesium periodate, potassium tetrachlorozincate and pentaerythritol are presented.


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