Synthesis, Morphology and Photophysical Properties of Rod-Coil Copolymers

2009 ◽  
Vol 79-82 ◽  
pp. 2095-2098
Author(s):  
Yang Yen Yu ◽  
Wen Chen Chien ◽  
Chung Yi Hsu
Keyword(s):  
Photophysical Properties ◽  
Mixed Solvents ◽  
Blue Shift ◽  
Morphological Transformation ◽  
Good Thermal Stability ◽  
Lamellar Morphology ◽  
Long Rod ◽  
Spherical Micelles ◽  
Large Compound ◽  
Thermal Stability Of

The synthesis, morphology, and photophysical properties of poly[2,7-(9,9- dihexylfluorene)]-block-poly(2-vinyl pyridine) (PF-b-P2VP) with different coil lengths in mixed solvents of THF/methanol are reported. A flakes-like lamellar morphology is observed at a short coil length of PF-b-P2VP. As the coil length increases, a spherical and large compound micelle is formed. Upon further increase of the coil length, the morphological transformation from spherical micelles to long rod-like structures is observed. TGA results indicate a good thermal stability of the prepared copolymers. The spectra of optical absorption for the PF-b-P2VP in solution have a blue shift when the fraction of methanol in the mixed solvent increases. The present study shows that the significance of the rod/coil ratio and selective solvent content on the aggregate morphologies and photophysical properties of the rod-coil block copolymers.

scholarly journals Synthesis and Morphological Transformation of Conjugated Amphiphilic Diblock Copolymers in Mixed Solvents

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Yang-Yen Yu ◽  
Chung-Yi Hsu ◽  
Guo-You Li
Keyword(s):  
Diblock Copolymers ◽  
Photophysical Properties ◽  
Mixed Solvents ◽  
Spectral Shift ◽  
Amphiphilic Copolymers ◽  
Morphological Transformation ◽  
Amphiphilic Diblock Copolymers ◽  
Copolymer Poly ◽  
Large Compound ◽  
Poor Solvent

The synthesis, morphological transformation, and photophysical properties of a rod-coil block copolymer, poly[2,7-(9,9-dihexylfluorene)]-block-poly(2-vinylpyridine) (PF-b-P2VP), with P2VP coils of various lengths in a mixed methanol/tetrahydrofuran (MeOH/THF) solvent are reported. Various morphological structures of PF-b-P2VP aggregates, including spheres, short worm-like structures, long cylinders, and large compound micelles (LCMs), were observed after varying the coil length of PF-b-P2VP and the selectivity of mixed solvents. These aggregated structures demonstrated considerable variation with regard to optical absorption, fluorescence, and the PL quantum yield of rod-coil copolymers. The degree of hypsochromic spectral shift was enhanced as the length of P2VP coils and the content of poor solvent increased. This study reveals the influence of coil length and selectivity of solvents on the morphology and the optical characteristics of rod-coil amphiphilic copolymers.

Synthesis and Characterization of Luminescent Rod-Coil Poly[2,7-(9,9- Dihexylfluorene)] - Block-Poly(2-(Dimethylamino) Ethyl Methacrylate) by Atom Transfer Radical Polymerization

2008 ◽  
Vol 47-50 ◽  
pp. 642-645
Author(s):  
Yang Yen Yu ◽  
Wen Chen Chien ◽  
Chia Liang Tsai
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Photophysical Properties ◽  
Mixed Solvents ◽  
Solvent System ◽  
Synthesis And Characterization ◽  
Photoluminescence Properties ◽  
Ethyl Methacrylate ◽  
Large Compound

The synthesis, morphology, and photophysical properties of Poly[2,7-(9,9-dihexyl fluorene)]- block-poly(2-(Dimethylamino) ethyl methacrylate) (PF-b-PDMAEMA) copolymers in various mixed solvents, i.e., THF/MeOH, DMF/MeOH, and 1,4-Dioxane/MeOH, with methanol contents of 0, 10, 25, 50, 75, 90 vol.% were reported. TEM images showed that different aggregate morphologies of PF-b-PDMAEMA, including spherical and large compound micelles, cylinder, nanorods, long stick-like structure, could be prepared by introducing different amount of methanol into the copolymer/solvent system. The results indicated that aggregate morphologies of PF-b-PDMAEMA, which obtained from various coil lengths and mixed solvents, had a great influenced on the optical and photoluminescence properties of the prepared PF-b-PDMAEMA copolymers.

scholarly journals Morphological Transformation and Photophysical Properties of Polyfluorene-Based Luminescent Rod-Coil Block Copolymers

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yang-Yen Yu ◽  
Chun-Yen Huang
Keyword(s):  
Thermal Stability ◽  
Block Copolymers ◽  
Fluorescence Quenching ◽  
Fluorescence Spectra ◽  
Annealing Temperature ◽  
Photophysical Properties ◽  
Morphological Transformation ◽  
Solvent Selectivity ◽  
Thermal Stability Of

The morphologies, synthesis, and photophysical characterizations of poly[2,7-(9,9-dihexylfluorene)]-block-poly(2-(diethylamino)ethylmethacrylate) using amphiphilic rod-coil (PF-b-PDEAEMA) were demonstrated. The aggregation morphologies of PF13-b-PDEAEMA100 were manipulated by tuning the selectivity of mixed THF/methanol solvents with methanol contents ranging from 0 to 90 vol%. The morphological transformation of PF13-b-PDEAEMA100 caused significant changes in its photophysical properties, including absorption, fluorescence spectra, and fluorescence quenching. Moreover, the thermal stability of PF13-b-PDEAEMA100 was investigated by varying the annealing temperature. The results of the present study suggest that the solvent selectivity influences the photophysical properties and aggregation morphologies of rod-coil block copolymers in solid and solution states.

Analysis of luminescence, morphological and thermal behaviour of conjugated polymer/CdS electrospun nanofiber

2021 ◽  
pp. 002199832110075
Author(s):  
PS Umabharathi ◽  
S Karpagam
Keyword(s):  
Thermal Stability ◽  
Composite Nanofibers ◽  
Cadmium Sulphide ◽  
Blue Shift ◽  
Sem Analysis ◽  
Tem Analysis ◽  
Good Thermal Stability ◽  
Ftir Technique ◽  
Significant Blue Shift ◽  
Thermal Stability Of

Electro spun composite nanofibers of three series were prepared using different polymers (P1, P2, P3) and cadmium sulphide (CdS). Organic polymers of carbazole based quinoline (P1), quinoxaline (P2), and pyrazine (P3) hybrid with inorganic CdS nanofibers were characterized by XRD and FTIR technique. Collective arrangement of spiderweb-like morphology was observed for all nanofibers. Deviations of absorption and photoluminescence were monitored and a significant blue shift was found after doping CdS and PVA. It was found that the changes in the PL spectra of polymers originated from the chemical interactions between polymer and CdS. The diameter of nanofibers was observed as 127-347 nm from SEM analysis and 66-213 nm from TEM analysis. Optimum thermal stability of the composite nanofibers was achieved up to 200 °C. Compared with pure polymers and CdS, present nanofibers were good thermal stability, apparent blue shift with bluish emission which is suitable for optoelectronics application.

High partial thermal conductivity of luminescence sites: a crucial factor for reducing the heat-induced lowering of the luminescence efficiency

2021 ◽  
Author(s):  
Ni Luo ◽  
Jing Xu ◽  
Xiyue Cheng ◽  
ZhenHua Li ◽  
Yidong Huang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Practical Applications ◽  
Good Thermal Stability ◽  
The Past ◽  
Luminescence Efficiency ◽  
Thermal Stability Of

The good thermal stability of a phosphor is crucial for its practical applications. Unfortunately, in the past decades, only Gurney-Mott equation was available to describe the relation between the luminescence...

scholarly journals Effect of Sepiolite-Loaded Fe2O3 on Flame Retardancy of Waterborne Polyurethane

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Tong Xu ◽  
Di Qian ◽  
Yelei Hu ◽  
Yuanzhao Zhu ◽  
Yi Zhong ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Waterborne Polyurethane ◽  
Layer By Layer ◽  
Solution Deposition ◽  
Good Thermal Stability ◽  
Layer Method ◽  
Combustion Tests ◽  
Microscopic Morphology ◽  
Coated Cotton ◽  
Thermal Stability Of

In this study, a kind of inorganic composite flame retardant (Sep@Fe2O3) was prepared by combining solution deposition and calcination methods using sepiolite microfiber material as carrier. This inorganic compound flame retardant was combined with waterborne polyurethane (WPU) through layer-by-layer method to prepare WPU composites. The SEM and EDS, TEM, and XRD were used to characterize the microscopic morphology and crystal structure of WPU composites. Thermogravimetric analysis tests confirmed the good thermal stability of WPU/Sep@Fe2O3 composites; at the temperature of 600°C, the carbon residual percentage of WPU/Sep, WPU/Fe2O3, and WPU/Sep@Fe2O3 composites is 7.3%, 12.2%, and 13.4%, respectively, higher than that of WPU (1.4%). Vertical combustion tests proved better flame-retardant property of WPU/Sep@Fe2O3 composite-coated cotton than noncoated cotton. The microcalorimeter test proved that the PHRR of WPU/Sep@Fe2O3 composites decreased by 61% compared with that of WPU. In addition, after combining with Sep@Fe2O3, the breaking strength of WPU increased by 35%.

Thermal Stability of Solid Aluminum Electrolytic Capacitors with Conductive Polyaniline Counter Electrode

2012 ◽  
Vol 512-515 ◽  
pp. 1018-1021
Author(s):  
Xu Fei Zhu ◽  
Long Fei Jiang ◽  
Wei Xing Qi ◽  
Chao Lu ◽  
Ye Song
Keyword(s):  
Thermal Stability ◽  
Counter Electrode ◽  
Electrolytic Capacitor ◽  
Aluminum Electrolytic Capacitor ◽  
Dodecylbenzenesulfonic Acid ◽  
Excellent Thermal Stability ◽  
High Frequencies ◽  
Solid Aluminum ◽  
Good Thermal Stability ◽  
Thermal Stability Of

To overcome the risk of electrolyte leakage and the shortcoming of higher impedance at high frequencies for the conventional aluminum electrolytic capacitor impregnated with electrolyte solutions, solid aluminum electrolytic capacitor employing conducting polyaniline (PANI) as a counter electrode was developed. The as-fabricated solid capacitors have very low impedances at high frequencies and excellent thermal stability. The superior performances can be ascribed to high conductivity and good thermal stability of the camphorsulfonic acid (CSA)-dodecylbenzenesulfonic acid (DBSA) co-doped PANI.

A 4′-(4-carboxyphenyl)-3,2′:6′,3′′-terpyridine-based luminescent cadmium(II) coordination polymer for the detection of 2,4,6-trinitrophenol

2019 ◽  
Vol 75 (5) ◽  
pp. 508-513 ◽  
Author(s):  
Bin Xu ◽  
Fuming Luo ◽  
Guodong Tang ◽  
Jinfang Zhang
Keyword(s):  
Coordination Polymer ◽  
Layer Structure ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quenching Effect ◽  
Good Thermal Stability ◽  
Octahedral Environment ◽  
Strong Luminescence ◽  
Thermal Stability Of

The title coordination polymer, poly[bis[μ3-4-(3,2′:6′,3′′-terpyridin-4′-yl)benzoato]cadmium(II)], [Cd(C22H14N3O2)2] n or [Cd(3-cptpy)2] n , (I), has been synthesized solvothermally and characterized by IR spectroscopy, thermogravimetric analysis, and single-crystal and powder X-ray diffraction. The structure is composed of 3-cptpy− ligands bridging Cd atoms, with each Cd atom coordinated by six ligands and each ligand coordinating to three Cd atoms. Each Cd atom is in a slightly distorted trans-N2O4 octahedral environment, forming a two-dimensional layer structure with a (3,6)-connected topology. Layers are linked to each other by π–π stacking, resulting in a three-dimensional supramolecular framework. The strong luminescence and good thermal stability of (I) indicate that it can potentially be used as a luminescence sensor. The compound also shows a highly selective and sensitive response to 2,4,6-trinitrophenol through the luminescence quenching effect.

Novel Electric Responsive Columnar Liquid Crystals based on Perylene Tetra sec-alkyl Ester Derivatives

2013 ◽  
Vol 66 (6) ◽  
pp. 692 ◽  
Author(s):  
Lei Wang ◽  
Qing Cui ◽  
Xiao-Fang Chen ◽  
Yang Li ◽  
Zheng-Qiang Li ◽  
...  
Keyword(s):  
Electric Field ◽  
Molecular Orbital ◽  
Indium Tin Oxide ◽  
Photophysical Properties ◽  
Mixed Solvents ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Mirror Image ◽  
Alkyl Ester ◽  
Fluorescence Emission Spectra

A series of novel perylene tetra sec-alkyl ester compounds were successfully designed and synthesised. The photophysical properties were investigated and the UV absorption and fluorescence emission spectra displayed a mirror-image relationship. The compound PS8 showed the highest fluorescent quantum yield, while the fluorescence of PS8 was quenched in the aggregated state in mixed solvents. Moreover, the electrochemical properties of the perylene derivatives were studied to determine the molecules’ highest occupied molecular orbital and lowest unoccupied molecular orbital levels by cyclic voltammetry. The most important result was that PS8 exhibited a columnar phase at room temperature and was responsive to an electric field. PS8 could perpendicularly orient to an applied electric field. In addition, highly oriented face-on alignment was achieved on indium tin oxide-covered glass by thermal annealing.

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