scholarly journals Chromo- and fluorophoric water-soluble polymers and silica particles by nucleophilic substitution reaction of poly(vinyl amine)

2010 ◽  
Vol 6 ◽  
Author(s):  
Katja Hofmann ◽  
Ingolf Kahle ◽  
Frank Simon ◽  
Stefan Spange
Keyword(s):  
Fluorescence Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Model Compound ◽  
Water Solubility ◽  
Fluorescence Emission ◽  
Silica Particles ◽  
Water Soluble ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
New Compounds

Novel chromophoric and fluorescent carbonitrile-functionalized poly(vinyl amine) (PVAm) and PVAm/silica particles were synthesized by means of nucleophilic aromatic substitution of 8-oxo-8H-acenaphtho[1,2-b]pyrrol-9-carbonitrile (1) with PVAm in water. The water solubility of 1 has been mediated by 2,6-O-β-dimethylcyclodextrin or by pre-adsorption onto silica particles. Furthermore, 1 was converted with isopropylamine into the model compound 1-M. All new compounds were characterized by NMR, FTIR, UV–vis and fluorescence spectroscopy. The solvent-dependent UV–vis absorption and fluorescence emission band positions of the model compound and the carbonitrile-functionalized PVAm were studied and interpreted using the empirical Kamlet–Taft solvent parameters π * (dipolarity/polarizability), α (hydrogen-bond donating capacity) and β (hydrogen-accepting ability) in terms of the linear solvation energy relationship (LSER). The solvent-independent regression coefficients a, b and s were determined using multiple linear correlation analysis. It is shown, that the chains of the polymer have a significant influence on the solvatochromic behavior of 1-P. The structure of the carbonitrile 1-Si bound to polymer-modified silica particles was studied by means of X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) measurements. Fluorescent silica particles were obtained as shown by fluorescence spectroscopy with a diffuse reflectance technique.

scholarly journals Effect of DMPA and Molecular Weight of Polyethylene Glycol on Water-Soluble Polyurethane

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1915 ◽  
Author(s):  
Eyob Wondu ◽  
Hyun Woo Oh ◽  
Jooheon Kim
Keyword(s):  
Molecular Weight ◽  
Contact Angle ◽  
Polyethylene Glycol ◽  
Photoelectron Spectroscopy ◽  
Water Solubility ◽  
Soft Segment ◽  
Water Soluble ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry

In this study water-soluble polyurethane (WSPU) was synthesized from isophorone diisocyanate (IPDI), and polyethylene glycol (PEG), 2-bis(hydroxymethyl) propionic acid or dimethylolpropionic acid (DMPA), butane-1,4-diol (BD), and triethylamine (TEA) using an acetone process. The water solubility was investigated by solubilizing the polymer in water and measuring the contact angle and the results indicated that water solubility and contact angle tendency were increased as the molecular weight of the soft segment decreased, the amount of emulsifier was increased, and soft segment to hard segment ratio was lower. The contact angle of samples without emulsifier was greater than 87°, while that of with emulsifier was less than 67°, indicating a shift from highly hydrophobic to hydrophilic. The WSPU was also analyzed using Fourier transform infrared spectroscopy (FT-IR) to identify the absorption of functional groups and further checked by X-ray photoelectron spectroscopy (XPS). The molecular weight of WSPU was measured using size-exclusion chromatography (SEC). The structure of the WSPU was confirmed by nuclear magnetic resonance spectroscopy (NMR). The thermal properties of WSPU were analyzed using thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC).

L-Histidine Stabilized Copper Nanoclusters as a Fluorescence Probe for Determination of Fluazinam

NANO ◽  
2020 ◽  
Vol 15 (05) ◽  
pp. 2050063
Author(s):  
Zhifeng Cai ◽  
Xiu Yin ◽  
Jingling Fang ◽  
Jie Zhao ◽  
Tianqi Wu ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Photoelectron Spectroscopy ◽  
Water Solubility ◽  
Fluorescence Probe ◽  
Synthesis Method ◽  
Fluorescence Emission ◽  
Average Diameter ◽  
High Dispersion ◽  
Excitation Wavelength ◽  
One Pot

In this contribution, a one-pot synthesis method possessing the advantages of simple, green and low-cost had been researched for the preparation of L-histidine-stabilized Cu nanoclusters (Cu NCs). Subsequently, the structure and optical properties of as-prepared Cu NCs were studied by using Fourier transform infrared (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), fluorescence spectroscopy and UV-Vis absorption spectroscopy. TEM image of the Cu NCs showed high dispersion with an average diameter of 2.0[Formula: see text]nm. Fluorescence spectrum displayed that the Cu NCs emitted green fluorescence (emission wavelength of 492[Formula: see text]nm) under excitation wavelength of 393[Formula: see text]nm. Moreover, the as-synthesized Cu NCs illustrated excellent performances, such as good water solubility, UV stability and high-salt resistance. Interestingly, the fluorescence intensity of as-prepared Cu NCs was obviously quenched in the presence of fluazinam. Under optimal conditions, the relative fluorescence intensity was linear with the fluazinam concentrations from 1 to 40[Formula: see text][Formula: see text]M, with a detection limit of 0.25[Formula: see text][Formula: see text]M. Eventually, the fluorescence sensor was successfully used to determine fluazinam in real water samples.

Preparation of water-dispersive poly(3,4-ethylenedioxythiophene) (PEDOT) conductive nanoparticles in lignosulfonic acid solution

Holzforschung ◽  
2015 ◽  
Vol 69 (5) ◽  
pp. 539-545 ◽  
Author(s):  
Yonghong Deng ◽  
Zhuoxi Li ◽  
Xueqing Qiu ◽  
Dacheng Zhao
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Near Infrared ◽  
Water Solubility ◽  
Water Soluble ◽  
Polyelectrolyte Complexes ◽  
Continuous Polymerization ◽  
And Performance ◽  
Highly Hydrophobic ◽  
Lignosulfonic Acid

AbstractLignosulfonic acid (LS) has been applied both as dispersant and dopant for chemical polymerization of 3,4-ethylenedioxythiophene (EDOT). EDOT is successfully polymerized in LS aqueous solutions, resulting in a water-dispersive poly(3,4-ethylenedioxythiophene) (PEDOT) conductive nanoparticle (PEDOT:LS). The structure, intermolecular interaction, and performance of the PEDOT:LS were investigated by ultraviolet-visible-Near-infrared spectrophotometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, dynamic light scattering, transmission electron microscopy, X-ray photoelectron spectroscopy, and surface resistivity tester. Results were interpreted in a way that PEDOT:LS is a polyelectrolyte complex, in which the highly hydrophobic PEDOT is in the inner part of the particle and the LS-rich layer with high hydrophilicity is on its surface. During oxidizing reaction of EDOT to PEDOT in LS, the water-insoluble PEDOT product is adsorbed on the surface of water-soluble LS by electrostatic attraction and forms PEDOT:LS polyelectrolyte complexes. In this process, excess LS is needed to be adsorbed on the surface of PEDOT:LS complexes. The process is driven by π-π interaction to increase the water solubility and contributes to a continuous polymerization. The PEDOT:LS as coating has a good conductivity, transparency, humidity resistance, water resistance, and thermal stability and can be used as high-performance antistatic agents.

scholarly journals Preparation of water-soluble asphalt carbon dots and hyperchromic effect to Cr (VI)

2018 ◽  
Vol 238 ◽  
pp. 02007
Author(s):  
Lijuan Gao ◽  
Jia Sui ◽  
Xiaoqin Qiao ◽  
Chaoshuai Hu ◽  
Xuefei Zhao
Keyword(s):  
Carbon Dots ◽  
Water Solubility ◽  
Fluorescence Emission ◽  
Acid Precipitation ◽  
Water Soluble ◽  
Raw Material ◽  
Precipitation Method ◽  
Acid Oxidation ◽  
Excitation Wavelength ◽  
Uv Spectrum

Water-soluble asphalt carbon dots (W-CDs) was prepared from medium - temperature coal tar pitch as raw material, via mixed acid oxidation, alkali solubilization and acid precipitation method. It was observed that as-prepared W-CDs were irregular particles with good water dispersibility and the particle size was controlled by the pH of the acid precipitation solution by a polarizing microscope. Infrared spectroscopy confirmed that the surface of the W-CDs was functionalized by hydrophilic and color-promoting functional groups, which had good water solubility; the thermal weight loss proved to be good thermal stability below 200°C; the fluorescence spectrum proved that the fluorescence emission peak position of the carbon dots appears red shift with increase of excitation wavelength, with fluorescence conversion property, and its emission light intensity decreases, belonging to non-resonant fluorescence type of direct jump fluorescence; UV spectrum proves that the addition of W-CDs can be chromium (VI) CrO42- content The detection limit was increased from milligram to microgram; the molar absorptivity of CrO42- was increased by 4 times. The experimentally optimized W-CDs-ultraviolet-viscometry method for measuring CrO42- conditions: W-CDs to chromium ratio of 8:2, pH of 8, hexamethylenetetramine as a surfactant, and the solution was allowed to stand at room temperature for 45 min.

Synthesis of Hydrazinylpyridines via Nucleophilic Aromatic Substitution and Further Transformation to Bicyclo[2.2.2]octenes Fused with Two N-Aminosuccinimide Moieties

Synthesis ◽  
2020 ◽  
Author(s):  
Krištof Kranjc ◽  
Jernej Ekar
Keyword(s):  
Nucleophilic Substitution ◽  
Hydrazine Hydrate ◽  
Diethyl Ether ◽  
Water Solubility ◽  
Halogen Bond ◽  
Bidentate Ligand ◽  
Nucleophilic Aromatic Substitution ◽  
Thick Wall ◽  
Aromatic Substitution ◽  
User Friendly

AbstractEfficient and reliable synthesis of substituted hydrazinylpyridines in thick-wall ACE tubes via nucleophilic substitution of a chlorine substituent in different chloropyridines is presented. Hydrazine hydrate and alkylhydrazines were used as nucleophiles and simple alcohols and diethyl ether were the only organic solvents necessary, making the process environmentally and user friendly, potentially reaching 100% atomic efficiency. In the next step, transformations of succinic anhydride moieties fused to the bicyclo[2.2.2]octene framework into succinimide moieties via nucleophilic substitution of oxygens were conducted. As nucleophiles two of the synthesized hydrazinylpyridines (2-hydrazinyl-3-nitropyridine and 2-hydrazinyl-5-nitropyridine) and also hydrazine hydrate, phenylhydrazine, and 4-nitrophenylhydrazine were used. Reactions were again carried out in ACE tubes and only simple alcohols, diethyl ether, and acetone were needed as solvents. One of the prepared bicyclo[2.2.2]octene adducts displayed water solubility thus being a promising candidate for future studies as a novel bidentate ligand for various metal cations in aqueous solutions or acting as an unprecedented halogen bond acceptor.

Enzymatic Synthesis and Characterization of an Water-Soluble Conducting Poly (1,4-Diaminobenzene-Acrylic Acid)

2010 ◽  
Vol 148-149 ◽  
pp. 118-125
Author(s):  
Jia Yu Zeng ◽  
Wei Bo Zhang ◽  
Shi Qi Liao ◽  
Dong Xia Zhang ◽  
Yun Pu Wang ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Photoelectron Spectroscopy ◽  
Water Solubility ◽  
Thermo Gravimetric Analysis ◽  
Decomposition Temperature ◽  
Water Soluble ◽  
Gravimetric Analysis ◽  
Ft Ir ◽  
Acid Catalyzed

A polymerization between 1,4-diaminobenzene (PPD) and acrylic acid catalyzed by Horseradish Perodxidase (HRP) in an water buffer will be described in this article. The effects of the concentration of H2O2, the ratio of the acrylic acid to PPD, the pH of the buffer, and the reaction time of polymerization were investigated. Compared with conventional methods, the synthesis is simple and the conditions are mild. The conductivity, UV-vis spectra, FT-IR spectra, X-ray photoelectron spectroscopy (XPS), and the thermo-gravimetric analysis (TGA) of the resulting polymer were investigated also. The results show that the synthesized polymer (PAnI) is a self-doped poly(1,4-diaminobenzene-acrylic acid) with 1,4-disubstituted aromatic ring, and a higher electro-activity, water-solubility, its decomposition temperature is 498.8 °C.

BODIPY Fluorophores for Membrane Potential Imaging

2019 ◽  
Author(s):  
Jenna Franke ◽  
Benjamin Raliski ◽  
Steven Boggess ◽  
Divya Natesan ◽  
Evan Koretsky ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Water Solubility ◽  
Water Soluble ◽  
Voltage Sensitivity ◽  
Chemical Transformations ◽  
Direct Modification ◽  
Biological Compatibility ◽  
Meso Position ◽  
Ionizable Groups ◽  
Boron Center

Fluorophores based on the BODIPY scaffold are prized for their tunable excitation and emission profiles, mild syntheses, and biological compatibility. Improving the water-solubility of BODIPY dyes remains an outstanding challenge. The development of water-soluble BODIPY dyes usually involves direct modification of the BODIPY fluorophore core with ionizable groups or substitution at the boron center. While these strategies are effective for the generation of water-soluble fluorophores, they are challenging to implement when developing BODIPY-based indicators: direct modification of BODIPY core can disrupt the electronics of the dye, complicating the design of functional indicators; and substitution at the boron center often renders the resultant BODIPY incompatible with the chemical transformations required to generate fluorescent sensors. In this study, we show that BODIPYs bearing a sulfonated aromatic group at the meso position provide a general solution for water-soluble BODIPYs. We outline the route to a suite of 5 new sulfonated BODIPYs with 2,6-disubstitution patterns spanning a range of electron-donating and -withdrawing propensities. To highlight the utility of these new, sulfonated BODIPYs, we further functionalize them to access 13 new, BODIPY-based voltage-sensitive fluorophores. The most sensitive of these BODIPY VF dyes displays a 48% ΔF/F per 100 mV in mammalian cells. Two additional BODIPY VFs show good voltage sensitivity (≥24% ΔF/F) and excellent brightness in cells. These compounds can report on action potential dynamics in both mammalian neurons and human stem cell-derived cardiomyocytes. Accessing a range of substituents in the context of a water soluble BODIPY fluorophore provides opportunities to tune the electronic properties of water-soluble BODIPY dyes for functional indicators.

scholarly journals Modification of Wood with Monoethanolamino-borate by The Data of X-Ray Photoelectron Spectroscopy

2018 ◽  
Vol 196 ◽  
pp. 04005
Author(s):  
Irina Stepina ◽  
Irina Kotlyarova
Keyword(s):  
Particle Size ◽  
Photoelectron Spectroscopy ◽  
Model Compound ◽  
Hydrolytic Stability ◽  
Photoelectron Spectra ◽  
Wood Cellulose ◽  
Rapid Loss ◽  
X Ray ◽  
Wood Protection ◽  
Cellulose Materials

The difficulty of wood protection from biocorrosion and fire is due to the fact that modifiers in use are washed out from the surface of the substrate under the influence of environmental factors. This results in a rapid loss of the protective effect and other practically important wood characteristics caused by the modification. To solve this problem is the aim of our work. Here, monoethanolaminoborate is used as a modifier, where electron-donating nitrogen atom provides a coordination number equal to four to a boron atom, which determines the hydrolytic stability of the compounds formed. Alpha-cellulose ground mechanically to a particle size of 1 mm at most was used as a model compound for the modification. X-ray photoelectron spectra were recorded on the XSAM-800 spectrometer (Kratos, UK). Prolonged extraction of the modified samples preceded the registration of the photoelectron spectra to exclude the fixation of the modifier molecules unreacted with cellulose. As a result of the experiment, boron and nitrogen atoms were found in the modified substrate, which indicated the hydrolytic stability of the bonds formed between the modifier molecules and the substrate. Therefore monoethanolaminoborate can be considered as a non-extractable modifier for wood-cellulose materials.

scholarly journals Machine learning meets mechanistic modelling for accurate prediction of experimental activation energies

2021 ◽  
Author(s):  
Kjell Jorner ◽  
Tore Brinck ◽  
Per-Ola Norrby ◽  
David Buttar
Keyword(s):  
Machine Learning ◽  
Activation Energies ◽  
Accurate Prediction ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Mechanistic Modelling

Hybrid reactivity models, combining mechanistic calculations and machine learning with descriptors, are used to predict barriers for nucleophilic aromatic substitution.

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