Two-Dimensional Polymer Networks of Maleic Acid Copolymers and Poly(allylamine) by the Langmuir-Blodgett Technique

Langmuir ◽  
1994 ◽  
Vol 10 (2) ◽  
pp. 557-562 ◽  
Author(s):  
Burm Jong Lee ◽  
Toyoki Kunitake
Keyword(s):  
Maleic Acid ◽  
Polymer Networks ◽  
Two Dimensional ◽  
Langmuir Blodgett

Design and Synthesis of Two-Dimensional Covalent Organic Frameworks with Four-Arm Cores: Prediction of Remarkable Ambipolar Charge-Transport Properties

2019 ◽  
Author(s):  
Simil Thomas ◽  
Hong Li ◽  
Raghunath R. Dasari ◽  
Austin Evans ◽  
William Dichtel ◽  
...  
Keyword(s):  
Charge Transport ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Polymer Networks ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
Zinc Porphyrin ◽  
Design And Synthesis ◽  
Predicted Values

<p>We have considered three two-dimensional (2D) π-conjugated polymer networks (i.e., covalent organic frameworks, COFs) materials based on pyrene, porphyrin, and zinc-porphyrin cores connected <i>via</i> diacetylenic linkers. Their electronic structures, investigated at the density functional theory global-hybrid level, are indicative of valence and conduction bands that have large widths, ranging between 1 and 2 eV. Using a molecular approach to derive the electronic couplings between adjacent core units and the electron-vibration couplings, the three π-conjugated 2D COFs are predicted to have ambipolar charge-transport characteristics with electron and hole mobilities in the range of 65-95 cm<sup>2</sup>V<sup>-1</sup>s<sup>-1</sup>. Such predicted values rank these 2D COFs among the highest-mobility organic semiconductors. In addition, we have synthesized the zinc-porphyrin based 2D COF and carried out structural characterization via powder X-ray diffraction and surface area analysis, which demonstrates the feasability of these electroactive networks.</p>

Two-Dimensional Correlation Analysis, Fourier Self-Deconvolution, and Second-Derivative Studies on Assignments of the CH2 Stretching Bands for Cast Films of 2-Dodecyl-, 2-Pentadecyl-, and 2-Octadecyl-7,7,8,8-Tetracyanoquinodimethane

2000 ◽  
Vol 54 (5) ◽  
pp. 692-698 ◽  
Author(s):  
Hai-Shui Wang ◽  
Yukihiro Ozaki
Keyword(s):  
Infrared Spectra ◽  
Alkyl Chain ◽  
Second Derivative ◽  
Two Dimensional ◽  
Langmuir Blodgett ◽  
Cast Films ◽  
Band Region ◽  
Correlation Spectrum ◽  
Doublet Band ◽  
Different Origins

Infrared spectra have been measured for cast films of three kinds of 2-alkyl-7,7,8,8-tetracyanoquinodimethanes (C nTCNQ) prepared on KBr plates. Each infrared spectrum shows two components for the CH2 antisymmetric stretching band (2926 and 2918 cm−1), and the relative intensity of the two bands changes with the length of the alkyl chain. In contrast to the characteristic doublet band in the antisymmetric stretching band region, only one band seems to appear near 2850 cm−1 in the corresponding CH2 symmetric stretching band region. In order to reveal the number of the bands appearing in the CH2 antisymmetric and symmetric stretching regions and to explore the origins of these bands, Fourier self-deconvolution (FSD) and second-derivative methods have been applied to the infrared spectra of the cast films. The FSD analysis of the spectra for the three kinds of C nTCNQ derivatives measured at a 4 cm−1 resolution demonstrates that the CH2 symmetric stretching band also consists of two components (near 2853 and 2848 cm−1). The same conclusion has been obtained by the second derivative of the spectra measured at 1 cm−1 resolution. An asynchronous two-dimensional (2D) correlation spectrum created from time-dependent infrared spectra for a one-layer Langmuir–Blodgett (LB) film develops cross peaks at (2927 and 2916 cm−1) and (2854 and 2846 cm−1), suggesting that the bands at 2927 and 2916 cm−1 come from different species and those at 2854 and 2846 cm−1 also have different origins. The bands at 2918 and 2848 cm−1 may be due to the interdigitated part of the alkyl chain in the cast film, which has ordered ( trans-zigzag) form, while the bands near 2926 and 2853 cm−1 are probably ascribed to the noninterdigitated part of the alkyl chain, which has disordered form with several gauche conformations.

Two-Dimensional Electronic System in Conducting Langmuir-Blodgett Film of BEDO-TTF and Stearic Acid

2002 ◽  
Vol 376 (1) ◽  
pp. 263-268
Author(s):  
Yasuo Ishizaki ◽  
Makoto Suzuki ◽  
Hitoshi Ohnuki ◽  
Tatsuro Imakubo ◽  
Mitsuru Izumi
Keyword(s):  
Stearic Acid ◽  
Electronic System ◽  
Two Dimensional ◽  
Blodgett Film ◽  
Langmuir Blodgett ◽  
Langmuir Blodgett Film

Two-dimensional ferroelectricity and phase transitions in PVDF Langmuir-Blodgett films probed by second harmonic generation

2001 ◽  
Vol 35 (1-4) ◽  
pp. 23-29 ◽  
Author(s):  
O. A. Aktsipetrov ◽  
T. V. Misuryaev ◽  
T. V. Murzina ◽  
S. P. Palto ◽  
N. N. Petukhova ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Two Dimensional ◽  
Langmuir Blodgett ◽  
Langmuir Blodgett Films

Emission pattern of planar CdTe nanocrystal light source coated by two-dimensional Langmuir-Blodgett photonic crystal

2007 ◽  
Vol 27 (5-8) ◽  
pp. 968-971 ◽  
Author(s):  
S.G. Romanov ◽  
M. Bardosova ◽  
M. Pemble ◽  
C.M. Sotomayor Torres ◽  
N. Gaponik ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Light Source ◽  
Two Dimensional ◽  
Emission Pattern ◽  
Langmuir Blodgett ◽  
Cdte Nanocrystal
Sign in / Sign up

Export Citation Format

Share Document