Decorating the Edges of a 2D Polymer with a Fluorescence Label

2016 ◽  
Vol 138 (28) ◽  
pp. 8976-8981 ◽  
Author(s):  
Yingjie Zhao ◽  
Richard H. M. Bernitzky ◽  
Max J. Kory ◽  
Gregor Hofer ◽  
Johan Hofkens ◽  
...  
Keyword(s):  
Fluorescence Label ◽  
2D Polymer

Seeded Growth of Single-Crystal Two-Dimensional Covalent Organic Frameworks

2017 ◽  
Author(s):  
Austin M. Evans ◽  
Lucas R. Parent ◽  
Nathan C. Flanders ◽  
Ryan P. Bisbey ◽  
Edon Vitaku ◽  
...  
Keyword(s):  
Molecular Transport ◽  
Controlled Synthesis ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
Seeded Growth ◽  
Covalent Bonds ◽  
Crystalline Materials ◽  
Step Procedure ◽  
Structures And Properties ◽  
2D Polymer

<div> <div> <div> <p>Polymerizing monomers into periodic two-dimensional (2D) networks provides structurally precise, atomically thin macromolecular sheets linked by robust, covalent bonds. These materials exhibit desirable mechanical, optoelectrotronic, and molecular transport properties derived from their designed structure and permanent porosity. 2D covalent organic frameworks (COFs) offer broad monomer scope, but are generally isolated as polycrystalline, insoluble powders with limited processability. Here we overcome this limitation by controlling 2D COF formation using a two- step procedure. In the first step, 2D COF nanoparticle seeds are prepared with approximate diameters of 30 nm. Next, monomers are slowly added to suppress new nucleation while promoting epitaxial growth on the existing seeds to sizes of several microns. The resulting COF nanoparticles are of exceptional and unprecedented quality, isolated as single crystalline materials with micron-scale domain sizes. These findings advance the controlled synthesis of 2D layered COFs and will enable a broad exploration of synthetic 2D polymer structures and properties. </p> </div> </div> </div>

Seeded Growth of Single-Crystal Two-Dimensional Covalent Organic Frameworks

2017 ◽  
Author(s):  
Austin M. Evans ◽  
Lucas R. Parent ◽  
Nathan C. Flanders ◽  
Ryan P. Bisbey ◽  
Edon Vitaku ◽  
...  
Keyword(s):  
Molecular Transport ◽  
Controlled Synthesis ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
Seeded Growth ◽  
Covalent Bonds ◽  
Crystalline Materials ◽  
Step Procedure ◽  
Structures And Properties ◽  
2D Polymer

<div> <div> <div> <p>Polymerizing monomers into periodic two-dimensional (2D) networks provides structurally precise, atomically thin macromolecular sheets linked by robust, covalent bonds. These materials exhibit desirable mechanical, optoelectrotronic, and molecular transport properties derived from their designed structure and permanent porosity. 2D covalent organic frameworks (COFs) offer broad monomer scope, but are generally isolated as polycrystalline, insoluble powders with limited processability. Here we overcome this limitation by controlling 2D COF formation using a two- step procedure. In the first step, 2D COF nanoparticle seeds are prepared with approximate diameters of 30 nm. Next, monomers are slowly added to suppress new nucleation while promoting epitaxial growth on the existing seeds to sizes of several microns. The resulting COF nanoparticles are of exceptional and unprecedented quality, isolated as single crystalline materials with micron-scale domain sizes. These findings advance the controlled synthesis of 2D layered COFs and will enable a broad exploration of synthetic 2D polymer structures and properties. </p> </div> </div> </div>

Laterally functionalized pillar[5]arene: a new building block for covalent self-assembly

2017 ◽  
Vol 53 (64) ◽  
pp. 9024-9027 ◽  
Author(s):  
Shuang Fu ◽  
Guo An ◽  
Hongcheng Sun ◽  
Quan Luo ◽  
Chunxi Hou ◽  
...  
Keyword(s):  
Polymer Films ◽  
Self Assembly ◽  
Building Block ◽  
2D Polymer

Polymer nanocapsules and 2D-polymer films were successfully constructed by using a novel laterally functionalized pillararene derivative.

Feasibility Study of the Fabrication of 2D Polymer Photonic Crystals by X-Ray Lithography

2004 ◽  
pp. 279-286
Author(s):  
J. Kando ◽  
S. Achenbach ◽  
R. Fettig ◽  
J. Mohr ◽  
U. Wallrabe
Keyword(s):  
Photonic Crystals ◽  
Feasibility Study ◽  
X Ray ◽  
2D Polymer

scholarly journals Glutathione and zeaxanthin formation during high light stress in foliose lichens

2008 ◽  
Vol 53 (No. 8) ◽  
pp. 340-344 ◽  
Author(s):  
J. Štepigová ◽  
H. Vráblíková ◽  
J. Lang ◽  
K. Večeřová ◽  
M. Barták
Keyword(s):  
Xanthophyll Cycle ◽  
Light Exposure ◽  
Light Stress ◽  
High Light ◽  
Short Term ◽  
Xanthophyll Cycle Pigments ◽  
High Light Stress ◽  
Fluorescence Label ◽  
Thiol Binding ◽  
Pure Acetone

In the presented study, we describe techniques for glutathione and pigment determination in lichens used in our laboratory. Glutathione and xanthophyll cycle pigments, especially zeaxanthin, are important antioxidants protecting plants against various stresses. In our laboratory, the high light stress in lichens has been intensively studied for several years. We extract glutathione in HCl and determine it by thiol-binding fluorescence label monobromobimane. For pigment determination, homogenized lichen thalli are extracted with pure acetone. According to our results, the total amount of glutathione decreases after a short-term high light exposure, while the amount of zeaxanthin increases.

scholarly journals Synthese und Struktur diastereomerer, zweikerniger Kupferkomplexe [1] / Synthesis and Structure of Diastereomerie Dinuclear Copper Complexes [1]

1994 ◽  
Vol 49 (10) ◽  
pp. 1410-1414 ◽  
Author(s):  
Rolf W. Saalfrank ◽  
Oliver Struck ◽  
Karl Peters ◽  
Hans Georg von Schnering
Keyword(s):  
Structure Analysis ◽  
Copper Complexes ◽  
Molar Ratio ◽  
Dinuclear Copper ◽  
X Ray ◽  
Dark Green ◽  
2D Polymer ◽  
Light Green

Abstract Depolymerisation of a copper(II)/pyrrolidine-based 2D -polymer 2 by 4,4′-bipyridyl [molar ratio: 2 (CuL2) : 1 (Bipy)] and recrystallisation of the reaction product leads to two visually distinguishable crystal charges, composed of dark green octahedra meso-4 and light green rod-shaped crystals racem-5. Separation of the conglomerate of the morphologically different crystals is accomplished by pick out. The structure of the dinuelear complex racem-5 has been established unambigously by X-ray structure analysis. EPR and susceptibility measurements of mixtures of complex meso-4 and racem-5 indicate that there is no interaction be­tween the two copper(II) centres.

Anomalous Ostwald Ripening Enables 2D Polymer Crystals via Fast Evaporation

2019 ◽  
Vol 123 (20) ◽  
Author(s):  
Qiyun Tang ◽  
Marcus Müller ◽  
Christopher Y. Li ◽  
Wenbing Hu
Keyword(s):  
Ostwald Ripening ◽  
Polymer Crystals ◽  
2D Polymer

scholarly journals pH Behavior of Polymer Complexes between Poly(carboxylic acids) and Poly(acrylamide derivatives) Using a Fluorescence Label Technique

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1196 ◽  
Author(s):  
Yuriko Matsumura ◽  
Kaoru Iwai
Keyword(s):  
Hydrogen Bond ◽  
Carboxylic Acids ◽  
Interpolymer Complex ◽  
Interpolymer Complexes ◽  
Hydrogen Bond Formation ◽  
Label Technique ◽  
Fluorescence Label ◽  
Subsequent Decrease ◽  
Mixed Systems ◽  
Poly Acrylamide

In order to clarify the local environment during interpolymer complex formation between poly(carboxylic acids) and poly(acrylamide derivatives) with different N-substitutions, a fluorescence label technique was used. 3-(2-propenyl)-9-(4-N,N-dimethylaminophenyl) phenanthrene (VDP) was used as an intramolecular fluorescence probe. All polymers were synthesized by free radical polymerization. Interpolymer complexation was monitored by charge transfer emission from the VDP unit. Both of the poly(carboxylic acids) formed interpolymer complexes with poly(N,N-dimethylacrylamide) (polyDMAM). The micro-environments around the VDP unit in the acidic pH region for the poly(methacrylic acid) (polyMAAc) and polyDMAM mixed systems were more hydrophobic than those of the poly(acrylic acid) (polyAAc) and polyDMAM mixed systems, as the α-methyl group of the MAAc unit contributed to hydrophobicity around the polymer chain during hydrogen bond formation. This suggests that, when the poly(carboxylic acids) and poly(acrylamide derivatives) were mixed, with a subsequent decrease in the solution pH, a hydrogen bond was partially formed, following which the hydrophobicity of the micro-environment around the polymer chains was changed, resulting in the formation of interpolymer complexes. Moreover, the electron-donating ability of the carbonyl group in the poly(acrylamide derivatives) had an effect on complexation with poly(carboxylic acids).

On-surface formation of two-dimensional polymer via direct C–H activation of metal phthalocyanine

2015 ◽  
Vol 51 (14) ◽  
pp. 2836-2839 ◽  
Author(s):  
Qiang Sun ◽  
Chi Zhang ◽  
Liangliang Cai ◽  
Lei Xie ◽  
Qinggang Tan ◽  
...  
Keyword(s):  
High Resolution ◽  
Dft Calculations ◽  
Polymer Structure ◽  
Two Dimensional ◽  
Metal Phthalocyanine ◽  
Surface Formation ◽  
2D Polymer

From high-resolution UHV-STM imaging and DFT calculations, we successfully obtained a 2D polymer structure formed through direct C–H activation followed by an aryl–aryl coupling of a metal-phthalocyanine (CoPc) on Ag(110).

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