Broadening Absorption in Conductive Polymers through Cross-linkable Side Chains in a Nonconjugated Polymer Backbone

2010 ◽  
Vol 43 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Arpornrat Nantalaksakul ◽  
Kothandam Krishnamoorthy ◽  
S. Thayumanavan
Keyword(s):  
Conductive Polymers ◽  
Side Chains ◽  
Polymer Backbone

scholarly journals Variation of the Side Chain Branch Position Leads to Vastly Improved Molecular Weight and OPV Performance in 4,8-dialkoxybenzo[1,2-b:4,5-b′]dithiophene/2,1,3-benzothiadiazole Copolymers

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Robert C. Coffin ◽  
Christopher M. MacNeill ◽  
Eric D. Peterson ◽  
Jeremy W. Ward ◽  
Jack W. Owen ◽  
...  
Keyword(s):  
Thin Film ◽  
Molecular Weight ◽  
Thin Film Transistor ◽  
Power Conversion ◽  
Hole Mobility ◽  
Side Chain ◽  
Side Chains ◽  
Absorption Profile ◽  
Polymer Backbone ◽  
Chain Branch

Through manipulation of the solubilizing side chains, we were able to dramatically improve the molecular weight(Mw)of 4,8-dialkoxybenzo[1,2-b:4,5-b′]dithiophene (BDT)/2,1,3-benzothiadiazole (BT) copolymers. When dodecyl side chains (P1) are employed at the 4- and 8-positions of the BDT unit, we obtain a chloroform-soluble copolymer fraction withMwof 6.3 kg/mol. Surprisingly, by moving to the commonly employed 2-ethylhexyl branch (P2),Mwdecreases to 3.4 kg/mol. This is despite numerous reports that this side chain increases solubility andMw. By moving the ethyl branch in one position relative to the polymer backbone (1-ethylhexyl,P3),Mwis dramatically increased to 68.8 kg/mol. As a result of thisMwincrease, the shape of the absorption profile is dramatically altered, withλmax= 637 nm compared with 598 nm forP1and 579 nm forP2. The hole mobility as determined by thin film transistor (TFT) measurements is improved from~1×10−6 cm2/Vs forP1andP2to7×10−4 cm2/Vs forP3, while solar cell power conversion efficiency in increased to2.91%forP3relative to0.31%and0.19%forP1andP2, respectively.

The Mobility of Tryptophan and Dansyl Fluorophores in Labelled Poly(N-ethylacrylamide) and Poly(N-ethylmethacrylamide)

1993 ◽  
Vol 58 (10) ◽  
pp. 2383-2395 ◽  
Author(s):  
František Mikeš ◽  
Drahomír Výprachtický ◽  
Jan Pecka
Keyword(s):  
Conformational Changes ◽  
High Viscosity ◽  
Side Chains ◽  
Fluorescence Depolarization ◽  
Polymer Backbone ◽  
Short Side ◽  
Low Viscosity ◽  
Viscosity Range ◽  
Methylene Groups ◽  
Intramolecular Association

The mobility of tryptophan fluorophore in N-butyl-Nα-acetyltryptophanamide and in side chain of labelled poly(N-ethylacrylamide) and poly(N-ethylmethacrylamide) was investigated by the fluorescence depolarization method. The mobility of the fluorophore in the low-molecular-weight model is much higher than in side chains of the polymers. Different steric hindrance by the polymer backbone can explain the higher mobility of the fluorophore in poly(N-ethylacrylamide) and in poly(N-ethylmethacrylamide). The mobility of 5-dimethylamino-1-naphthalenesulfonamide (dansyl) fluorophore in side chains of labelled poly(N-ethylmethacrylamide) in the high-viscosity range increases with increasing number of methylene groups in side chains. The low-viscosity range, the rate s of conformational changes in short side chains (n = 2 - 7) are approximately constant and significantly decrease in long side chains (n = 10, 12). The drop in the rates is probably due to intramolecular association of the long hydrophobic chains in water.

Mechanically strong, fluorescent hydrogels from zwitterionic, fully π-conjugated polymers

2014 ◽  
Vol 50 (64) ◽  
pp. 8930-8933 ◽  
Author(s):  
Einat Elmalem ◽  
Frank Biedermann ◽  
Maik R. J. Scherer ◽  
Alexandros Koutsioubas ◽  
Chris Toprakcioglu ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Conjugated Polymer ◽  
Side Chains ◽  
Polymer Backbone

Mechanically strong supramolecular hydrogels can be obtained by combining a rigid, fully π-conjugated polymer backbone and zwitterionic side chains.

scholarly journals Rational Design of Donor Acceptor Based Semiconducting Copolymers with High Dielectric Constant

2020 ◽  
Author(s):  
Aiswarya Abhisek Mohapatra ◽  
Yifan Dong ◽  
Puttaraju Boregowda ◽  
Ashutosh Mohanty ◽  
Aditya Sadhanala ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Rational Design ◽  
Dielectric Constants ◽  
Side Chains ◽  
Free Charge ◽  
Coulombic Interaction ◽  
Polymer Backbone ◽  
Donor Acceptor

<div> <div> <div> <p>An efficient photogeneration of free charge carriers has long been recognized as the paramount challenge in organic photovoltaic (OPV) devices. The low dielectric constant organic semiconductors fall short to reduce strong Coulombic interaction of tightly bound exciton and hence lead to a loss mechanism in OPVs due to charge-carrier recombination. To circumvent this problem, we adopt a strategy to enhance the dielectric constant of organic semiconductors by incorporating tetraethyleneglycol (TEG) side-chains. We report synthesis of three new semiconducting copolymers by combining thiophene substituted diketopyrrolopyrrole (TDPP) monomer with three other monomeric units with varying electron donating strength: benzodithiophene (BBT-3TEG-TDPP), TDPP (TDPP-3TEG-TDPP) and naphthalene diimide (PNDITEG-TDPP). BBT-3TEG-TDPP and PNDITEG-TDPP showed highest dielectric constants (~ 5) at 1MHz frequency suggesting efficient contribution of dipolar polarization from TEG side-chains. To understand the electronic contribution of the polymer backbone and the polarity of TEG side-chains, and the resulting enhancement of the dielectric constant, we further performed first-principles density functional theory calculations. Single-component organic solar cells (OSC) fabricated utilizing these polymers resulted in poor performance which is attributed to the absence of free charge generation. Furthermore, transient absorption spectroscopy studies show low exciton diffusion length as observed in donor-acceptor type conjugated polymers. Our results suggest that, the strategy of enhancing dielectric constant with polar side-chains is not sufficient to reduce Coulombic interaction between hole and electron in OSCs. </p> </div> </div> </div>

Band gap tuning of narrow-polydispersity two-dimensional conductive polymers with electroactive side-chains

2014 ◽  
Vol 52 (9) ◽  
pp. 1217-1227 ◽  
Author(s):  
Yi-Lung Yang ◽  
Yi-Huan Lee ◽  
Yu-Ping Lee ◽  
Chi-Ju Chiang ◽  
Fong-Yu Hsu ◽  
...  
Keyword(s):  
Band Gap ◽  
Conductive Polymers ◽  
Side Chains ◽  
Two Dimensional ◽  
Band Gap Tuning

scholarly journals Temperature dependant structural changes in thin films of random semifluorinated PMMA copolymers

2013 ◽  
Vol 28 (S2) ◽  
pp. S144-S160 ◽  
Author(s):  
Dieter Jehnichen ◽  
Peter Friedel ◽  
Romy Selinger ◽  
Andreas Korwitz ◽  
Martin Wengenmayr ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Separation ◽  
Structural Changes ◽  
Bulk Material ◽  
Fluorine Content ◽  
Film Surface ◽  
Phase Behaviour ◽  
Side Chain ◽  
Side Chains ◽  
Polymer Backbone

Semifluorinated (SF) side chain polymers show phase separation between polymer backbone and SF side chains. Due to strong interaction between SF segments the side chains determine the structure behaviour strongly, often resulting in layered structures in which backbones and layers of SF side chains alternate. The interest in this work was directed to find out the dependence of these structures on concentration of SF side chains. Thin films of random copolymers consisting of methylmethacrylate (MMA) and semifluorinated side chain methacrylate (SFMA) segments and with different fluorine content in the perfluoroalkyl side chains (abbreviated as H10F10 and H2F8) were prepared by spin-coating. Phase separation and structure changes were initiated by external subsequent annealing. Corresponding bulk material served as basic information. Generation of ordered structures and variation of film parameters were observed using different X-ray scattering methods (XRR, GIWAXS, and GISAXS). The phase behaviour in bulk is governed by the SF side chain amount and their specific fluorine content which control the self-organization tendency of SF side chains. Additionally, the confinement in thin films generates an orientation of side chains normally to film surface.

scholarly journals Modified structure of two-dimensional polythiophene derivatives by incorporating electron-deficient units into terthiophene-vinylene conjugated side chains and the polymer backbone: synthesis, optoelectronic and self-assembly properties, and photovoltaic application

RSC Advances ◽  
2016 ◽  
Vol 6 (72) ◽  
pp. 67976-67985 ◽  
Author(s):  
Chuen-Yo Hsiow ◽  
Yu-Hsiang Lin ◽  
Rathinam Raja ◽  
Syang-Peng Rwei ◽  
Wen-Yen Chiu ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Self Assembly ◽  
Molecular Engineering ◽  
Side Chains ◽  
Two Dimensional ◽  
Photovoltaic Properties ◽  
Polymer Backbone ◽  
Photovoltaic Application

Molecular engineering on the conjugated side chains of two-dimensional (2D) conjugated polymers was conducted and its effect on the optical, electronic, self-assembly and photovoltaic properties was investigated.

scholarly journals A Molecular Shape Recognitive HPLC Stationary Phase Based on a Highly Ordered Amphiphilic Glutamide Molecular Gel

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1574
Author(s):  
Naoki Kawamoto ◽  
Yongxing Hu ◽  
Yutaka Kuwahara ◽  
Hirotaka Ihara ◽  
Makoto Takafuji
Keyword(s):  
Phase Transition ◽  
Stationary Phase ◽  
Separation Efficiency ◽  
Molecular Shape ◽  
Differential Scanning Calorimetric ◽  
Side Chains ◽  
Calorimetric Analysis ◽  
Polymer Backbone ◽  
Phenol Derivatives ◽  
Flexible Polymer

Chiral glutamide-derived lipids form self-assembled fibrous molecular gels that can be used as HPLC organic phases. In this study, HPLC separation efficiency was improved through the addition of branched amphiphilic glutamide lipids to the side chains of a terminally immobilized flexible polymer backbone. Poly(4-vinylpyridine) with a trimethoxysilyl group at one end was grafted onto the surface of porous silica particles (Sil−VP15, polymerization degree = 15), and the pyridyl side chains were quaternized with a glutamide lipid having a bromide group (BrG). Elemental analysis indicated that the total amount of the organic phase of the prepared stationary phase (Sil−VPG15) was 38.0 wt%, and the quaternization degree of the pyridyl groups was determined to be 32.5%. Differential scanning calorimetric analysis of a methanol suspension of Sil−VPG15 indicated that the G moieties formed a highly ordered structure below the phase transition temperature even on the silica surface, and the ordered G moieties exhibited a gel-to-liquid crystalline phase transition. Compared with a commercially available octadecylated silica column, the Sil−VPG15 stationary phase showed high selectivity toward polycyclic aromatic hydrocarbons, and particularly excellent separations were obtained for geometrical and positional isomers. Sil−VPG15 also showed highly selective separation for phenol derivatives, and bio-related molecules containing phenolic groups such as steroids were successfully separated. These separation abilities are probably due to multiple interactions between the elutes and the highly ordered functional groups, such as the pyridinium and amide groups, on the highly ordered molecular gel having self-assembling G moieties.

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