scholarly journals Synthesis and Characterization of Multifunctional Chiral and Photoactive Organic-Inorganic Block Copolymers of Poly(methylphenylsilane) with (R)-N-(1-phenylethyl)methacrylamide, Disperse Red 1 Methacrylate and Their optical and Photophysical Properties

2018 ◽  
Author(s):  
Km. Meenu ◽  
Dibyendu S. Bag ◽  
Rekha Lagarkha ◽  
Radha Tomar ◽  
Arvind Kumar Gupta
Keyword(s):  
Photophysical Properties ◽  
Visible Region ◽  
Photoluminescence Property ◽  
Secondary Amide ◽  
Inorganic Polymers ◽  
Photoluminescence Properties ◽  
Optical Absorbance ◽  
Stretching Vibration ◽  
Disperse Red 1 ◽  
Code Identification

Now-a-days, the thrust area of materials’ research is to develop multifunctional materials, which have multiple properties in a single functional material. We are interested to develop multifunctional polysilanes having special functional properties such as optical activity and photoluminescence (PL) properties. In this investigation, poly(methyl phenyl silane) (PMPS) was integrated with a chiral unit and a photoactive unit by in situ photopolymerization of  (R)-N-(1-phenyl ethyl) methacrylamide (R-NPEMAM) and disperse red 1 methacrylate (DR1MA) monomer in the presence of PMPS. PMPS acted as a macrophotoinitiator and by UV exposure it produced macroradicals which initiated polymerization of chiral and photoactive monomers. Thus a block copolymer of PMPS-b-(R-NPEMAM-ran-DR1MA) was synthesized.The synthesized multifunctional organic inorganic hybrid polymer samples were characterized by FTIR and NMR spectroscopy. The molecular weights of the samples were measured by GPC analysis. The optical, chiroptical and photoluminescence properties were studied. The narrow band at about 1638 cm-1 is due to C=O stretching vibration of -CONH- of the chiral unit.  A wide absorption peaks at 3444 cm-1 is the characteristic of NH trans stretching vibration of secondary amide group. The asymmetric stretching of NO2 group appeared at 1481 cm-1 and the characteristic peak at 1427 cm-1 was observed due to azo (-N=N-) group stretching of DR1MA unit. The Si-Si band of PMPS appeared at about 462 cm-1 in FTIR spectra. The optical absorbance observed at 272 nm is due to π-π* transition of aromatic ring and at 330 nm corresponds to σ-σ* transition of Si-Si bond. The other electronic absorption observed in the visible region at 475 nm corresponds to the combined contribution of n-π* and π-π* transition of DR1MA unit. The photoluminescence properties of such polymers were studied for the variation of concentration of the polymer solution and variation with excitation energy such as 275 nm, 325 nm and 475 nm in THF solvent. Such synthesized multifunctional photoactive organic-inorganic polymers having unusual optical, chiroptical and photoluminescence property may find novel optoelectronic (friend foe identification and secretive code identification) applications.

scholarly journals Synthesis and Characterization of Multifunctional Chiral and Photoactive Organic-Inorganic Block Copolymers of Poly(methylphenylsilane) with (R)-N-(1-phenylethyl)methacrylamide, Disperse Red 1 Methacrylate and Their optical and Photophysical Properties

2018 ◽  
Author(s):  
K. Meenu ◽  
Dibyendu S. Bag ◽  
Rekha Lagarkha ◽  
Radha Tomar ◽  
Arvind Kumar Gupta
Keyword(s):  
Photophysical Properties ◽  
Visible Region ◽  
Photoluminescence Property ◽  
Secondary Amide ◽  
Inorganic Polymers ◽  
Photoluminescence Properties ◽  
Optical Absorbance ◽  
Stretching Vibration ◽  
Disperse Red 1 ◽  
Code Identification

Now-a-days, the thrust area of materials’ research is to develop multifunctional materials, which have multiple properties in a single functional material. We are interested to develop multifunctional polysilanes having special functional properties such as optical activity and photoluminescence (PL) properties. In this investigation, poly(methyl phenyl silane) (PMPS) was integrated with a chiral unit and a photoactive unit by in situ photopolymerization of  (R)-N-(1-phenyl ethyl) methacrylamide (R-NPEMAM) and disperse red 1 methacrylate (DR1MA) monomer in the presence of PMPS. PMPS acted as a macrophotoinitiator and by UV exposure it produced macroradicals which initiated polymerization of chiral and photoactive monomers. Thus a block copolymer of PMPS-b-(R-NPEMAM-ran-DR1MA) was synthesized.The synthesized multifunctional organic inorganic hybrid polymer samples were characterized by FTIR and NMR spectroscopy. The molecular weights of the samples were measured by GPC analysis. The optical, chiroptical and photoluminescence properties were studied. The narrow band at about 1638 cm-1 is due to C=O stretching vibration of -CONH- of the chiral unit.  A wide absorption peaks at 3444 cm-1 is the characteristic of NH trans stretching vibration of secondary amide group. The asymmetric stretching of NO2 group appeared at 1481 cm-1 and the characteristic peak at 1427 cm-1 was observed due to azo (-N=N-) group stretching of DR1MA unit. The Si-Si band of PMPS appeared at about 462 cm-1 in FTIR spectra. The optical absorbance observed at 272 nm is due to π-π* transition of aromatic ring and at 330 nm corresponds to σ-σ* transition of Si-Si bond. The other electronic absorption observed in the visible region at 475 nm corresponds to the combined contribution of n-π* and π-π* transition of DR1MA unit. The photoluminescence properties of such polymers were studied for the variation of concentration of the polymer solution and variation with excitation energy such as 275 nm, 325 nm and 475 nm in THF solvent. Such synthesized multifunctional photoactive organic-inorganic polymers having unusual optical, chiroptical and photoluminescence property may find novel optoelectronic (friend foe identification and secretive code identification) applications.

scholarly journals Indenopyrans – synthesis and photoluminescence properties

2016 ◽  
Vol 12 ◽  
pp. 825-834 ◽  
Author(s):  
Andreea Petronela Diac ◽  
Ana-Maria Ţepeş ◽  
Albert Soran ◽  
Ion Grosu ◽  
Anamaria Terec ◽  
...  
Keyword(s):  
Solid State ◽  
Emission Band ◽  
Fluorescence Spectra ◽  
Photophysical Properties ◽  
Quantum Yields ◽  
Band Broadening ◽  
Photoluminescence Properties ◽  
Fluorescence Quantum Yields ◽  
Blue Emitters ◽  
Solid State Fluorescence

New indeno[1,2-c]pyran-3-ones bearing different substituents at the pyran moiety were synthesized and their photophysical properties were investigated. In solution all compounds were found to be blue emitters and the trans isomers exhibited significantly higher fluorescence quantum yields (relative to 9,10-diphenylanthracene) as compared to the corresponding cis isomers. The solid-state fluorescence spectra revealed an important red shift of λmax due to intermolecular interactions in the lattice, along with an emission-band broadening, as compared to the solution fluorescence spectra.

Effect of Different Catalysts and Growth Temperature on the Photoluminescence Properties of Zinc Silicate Nanostructures Grown via VLS Method

2021 ◽  
Author(s):  
Ghfoor Muhammad ◽  
Imran Murtaza ◽  
Rehan Abid ◽  
Naeem Ahmad
Keyword(s):  
Energy Levels ◽  
Visible Region ◽  
Wide Bandgap ◽  
Visible Spectral Range ◽  
Zinc Silicate ◽  
Band Spectrum ◽  
Photoluminescence Properties ◽  
Display Devices ◽  
Crystal Growth Kinetics ◽  
Potential Applications

Abstract Herein, we explore the photoluminescence properties of zinc silicate (Zn2SiO4) nanostructures synthesized by vapor-liquid-solid (VLS) mode of growth using three different catalysts (Sn, Ag and Mn). Different catalysts significantly influence the growth rate which in turn has an impact on the structure and hence the photoluminescence of the prepared zinc silicate nanostructures. Zn2SiO4 has a wide bandgap of about 5.5 eV and in its pure form, it does not emit in visible region due to its inner shell electronic transitions between the 3d5 energy levels. However, the incorporation of different catalysts (Sn, Ag and Mn) at different growth temperatures into the Zn2SiO4 crystal growth kinetics provides wide visible spectral range of photoluminescence (PL) emissions. PL analysis shows broad multi-band spectrum in the visible region and distinct colours (red, yellow, green, blue, cyan and violet) are obtained depending on the crystalline structure of the prepared nanostructures. The allowed transitions due to the effect of different catalysts on zinc silicate lattice offer a huge cross-section of absorption that generates strong photoluminescence. The correlation between the structural and optical properties of the synthesized nanostructures is discussed in detail. The synthesized photoluminescent nanostructures have potential applications in solid-state lighting and display devices.

scholarly journals A Review of the Synthesis and Photoluminescence Properties of Hybrid ZnO and Carbon Nanomaterials

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Protima Rauwel ◽  
Martin Salumaa ◽  
Andres Aasna ◽  
Augustinas Galeckas ◽  
Erwan Rauwel
Keyword(s):  
Carbon Nanostructures ◽  
Carbon Nanomaterials ◽  
Surface Defects ◽  
Deep Level ◽  
Visible Region ◽  
Cost Effective ◽  
Photoluminescence Properties ◽  
Efficient Energy Transfer ◽  
Photoluminescence Emission ◽  
Synthesis Routes

Photoluminescent ZnO carbon nanomaterials are an emerging class of nanomaterials with unique optical properties. They each, ZnO and carbon nanomaterials, have an advantage of being nontoxic and environmentally friendly. Their cost-effective production methods along with simple synthesis routes are also of interest. Moreover, ZnO presents photoluminescence emission in the UV and visible region depending on the synthesis routes, shape, size, deep level, and surface defects. When combined with carbon nanomaterials, modification of surface defects in ZnO allows tuning of these photoluminescence properties to produce, for example, white light. Moreover, efficient energy transfer from the ZnO to carbon nanostructures makes them suitable candidates not only in energy harvesting applications but also in biosensors, photodetectors, and low temperature thermal imaging. This work reviews the synthesis and photoluminescence properties of 3 carbon allotropes: carbon quantum or nanodots, graphene, and carbon nanotubes when hybridized with ZnO nanostructures. Various synthesis routes for the hybrid materials with different morphologies of ZnO are presented. Moreover, differences in photoluminescence emission when combining ZnO with each of the three different allotropes are analysed.

K3Eu5(PO4)6: hydrothermal synthesis, crystal structure and photoluminescence properties

2019 ◽  
Vol 75 (7) ◽  
pp. 883-890 ◽  
Author(s):  
Ya-Li Xue ◽  
Ai-Yun Zhang ◽  
Xiao-Yang Han ◽  
Xiao-Qi Cui ◽  
Ling Deng ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrothermal Synthesis ◽  
Uv Light ◽  
Three Dimensional ◽  
Visible Region ◽  
Monoclinic Space Group ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Strong Luminescence ◽  
Light Excitation

An anhydrous orthophosphate, K3Eu5(PO4)6 (tripotassium pentaeuropium hexaphosphate), has been prepared by a high-temperature solid-state reaction combined with hydrothermal synthesis, and its crystal structure was determined by single-crystal X-ray diffraction analysis (SC-XRD). The results show that the compound crystallizes in the monoclinic space group C2/c and the structure features a three-dimensional framework of [Eu5(PO4)6]∞, with the tunnel filled by K+ ions. The IR spectrum, UV–Vis spectrum and luminescence properties of polycrystalline samples of K3Eu5(PO4)6, annealed at temperatures of 650, 700, 750, 800 and 850 °C, were investigated. Although with a full Eu3+ concentration (9.96 × 1021 ions cm−3), the self-activated phosphor K3Eu5(PO4)6 shows s strong luminescence emission intensity with a quantum yield of 37%. Under near-UV light excitation (393 nm), the series of samples shows the characteristic emissions of Eu3+ ions in the visible region from 575 to 715 nm. The sample sintered at 800 °C gives the strongest emission and its lifetime sintered at 800 °C (1.88 ms) is also the longest of all.

Reactions of OH Radicals with Acetylacetone in Aqueous Solution. A Pulse Radiolysis and Electron Spin Resonance Study

1982 ◽  
Vol 37 (3) ◽  
pp. 368-375 ◽  
Author(s):  
R. K. Broszkiewicz ◽  
T. Söylemez ◽  
D. Schulte-Frohlinde
Keyword(s):  
Double Bond ◽  
Pulse Radiolysis ◽  
Visible Region ◽  
Alkaline Condition ◽  
Main Reaction ◽  
Electron Spin Resonance Study ◽  
Oh Radicals ◽  
Oh Radical ◽  
Keto Form ◽  
Optical Absorbance

Abstract Pulse radiolysis experiments monitoring optical absorbance as well as conductivity and in-situ ESR radiolysis studies show that the OH radical reacts with the enol (k=8.6 x 109 M-1 s-1) and the enolate (k = 7.4 X 109 M-1 s-1) forms of acetylacetone by addition to the C = C double bond in aqueous N2O saturated solution. The OH reaction with enol leads to equal amounts of two radicals, CH3COCHOHCOHCH3 (2) and CH3COCHC(OH)2CH3 (4), as determined by scavenger reactions. At pH less than 1 the radical CH3COCHCOCH3 (1) is observed by ESR spectroscopy showing that radical 2 and/or 4 eliminate water by proton catalyzed reactions. Under alkaline condition the OH adducts to the enolate eliminate OH -with rate constants larger than 105 s-1 leading to radical 1. G(OH-) is determined to be 5.6 showing that addition is the main reaction of OH with enolate. To a much smaller degree the OH radical is proposed to abstract an H atom from that CH3 group which is attached to the C -C double bond in enol and enolate, producing substituted allyl radicals which absorb in the visible region. The reaction of OH with the keto form has not been observed indicating that the rate constant of this reaction is significantly smaller than those with enol and enolate.

scholarly journals First–Principles Investigation of the Structural, Elastic, Electronic, and Optical Properties of α– and β–SrZrS3: Implications for Photovoltaic Applications

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 978
Author(s):  
Henry Igwebuike Eya ◽  
Esidor Ntsoenzok ◽  
Nelson Y. Dzade
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Visible Region ◽  
Charge Carriers ◽  
Band Gaps ◽  
Strong Light ◽  
Electronic And Optical Properties ◽  
Optical Absorbance ◽  
Effective Masses

Transition metal perovskite chalcogenides are attractive solar absorber materials for renewable energy applications. Herein, we present the first–principles screened hybrid density functional theory analyses of the structural, elastic, electronic and optical properties of the two structure modifications of strontium zirconium sulfide (needle–like α–SrZrS3 and distorted β–SrZrS3 phases). Through the analysis of the predicted electronic structures, we show that both α– and β–SrZrS3 materials are direct band gaps absorbers, with calculated band gaps of 1.38, and 1.95 eV, respectively, in close agreement with estimates from diffuse–reflectance measurements. A strong light absorption in the visible region is predicted for the α– and β–SrZrS3, as reflected in their high optical absorbance (in the order of 105 cm−1), with the β–SrZrS3 phase showing stronger absorption than the α–SrZrS3 phase. We also report the first theoretical prediction of effective masses of photo-generated charge carriers in α– and β–SrZrS3 materials. Predicted small effective masses of holes and electrons at the valence, and conduction bands, respectively, point to high mobility (high conductivity) and low recombination rate of photo-generated charge carriers in α– and β–SrZrS3 materials, which are necessary for efficient photovoltaic conversion.

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 Tuning the photophysical properties of BODIPY dyes through extended aromatic pyrroles

RSC Advances ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 173-179 ◽  
Author(s):  
Shawn Swavey ◽  
John Quinn ◽  
Michael Coladipietro ◽  
Kegan G. Cox ◽  
M. Kyle Brennaman
Keyword(s):  
Photophysical Properties ◽  
Visible Region ◽  
Step Process

A series of naphthyl and fluorantho-fused BODIPY dyes have been synthesized by a simple two-step process. These dyes display high molar absorptivities in the far visible region of the spectrum with emission quantum efficiencies at or near unity.

3D Ln–Organic Frameworks Featuring Lantern-Shaped Dihelicate Chains: Synthesis and Magnetic and Photophysical Properties

2016 ◽  
Vol 69 (9) ◽  
pp. 1062 ◽  
Author(s):  
Shengyun Liao ◽  
Peiyao Du ◽  
Yanping Zhang ◽  
Xin Fu ◽  
Wen Gu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Hydrothermal Reaction ◽  
Photophysical Properties ◽  
Metal Organic Framework ◽  
Visible Region ◽  
Infrared Region ◽  
X Ray Diffraction ◽  
Topological Network ◽  
Metal Organic

The in situ hydrothermal reaction of rare earth nitrate (Ln(NO3)3), 5-(4-carboxyl-1H-1,2,3-triazol-1-yl) isophthalic acid (H3ctia), and (NH4)2C2O4 resulted in the formation of a series of 3D 4f coordination polymers ([Ln(tia)(C2O4)0.5(H2O)]) (Ln = Nd (1), Sm (2), Eu (3), Gd (4), Tb (5), Dy (6), and tia2– = 5-(1H-1,2,3-triazol-1-yl) isophthalate). The results of single crystal X-ray diffraction reveal that the dinuclear lantern sub-building units ([Ln2(CO2)4]2+) are linked by C2O42– to form dihelicate chains, which are connected by tia2– to afford a novel 3D metal–organic framework with an unordinary 3-nodal (2,3,8)-connected topological network with the Schläfli symbol of {4.62}2{42.616.89.10}{6}. Complexes 2, 3, 5, and 6 exhibit strong fluorescent emissions in the visible region and complexes 1, 2, and 6 show characteristic fluorescent emissions in the near-infrared region. In addition, the magnetic properties of complexes 4, 5, and 6 were also investigated.

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