A recyclable, fluorescent, and colorimetric sensor for fluoride anion in water using a crosslinked polymer functionalized with hydroxyl quinolinium

The rheological and mechanical properties of crosslinked polymer gels arise from the structure of the gel network. In turn, the structure of the gel network results from: thermodynamically determined interactions between the polymer chain segments, the interactions of the crosslinking metal ion with the polymer, and the deformation history of the network. Interpretations of mechanical and rheological measurements on polymer gels invariably begin with a conceptual model of,the microstructure of the gel network derived from polymer kinetic theory. In the present work, we use freeze-etch replication TEM to image the polymer network morphology of titanium crosslinked hydroxypropyl guars in an attempt to directly relate macroscopic phenomena with network structure.

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The analysis of “Gels” in polymer films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100153786 ◽

1989 ◽

Vol 47 ◽

pp. 362-363

Author(s):

G. M. Brown ◽

D. F. Brown ◽

J. H. Butler

Keyword(s):

Molecular Weight ◽

Film Industry ◽

Local Stress ◽

Melt Index ◽

Polyethylene Films ◽

Crosslinked Polymer ◽

Polymeric Gels ◽

Mineral Particles ◽

Polymeric Species ◽

Special Concern

The term “gel”, in the jargon of the plastics film industry, may refer to any inclusion that produces a visible artifact in a polymeric film. Although they can occur in any plastic product, gels are a principle concern in films where they detract from the cosmetic appearance of the product and may compromise its mechanical strength by acting as local stress concentrators. Many film gels are small spheres or ellipsoids less than one millimeter in diameter whereas other gels are fusiform-shaped and may reach several centimeters in length. The actual composition of gel inclusions may vary from miscellaneous inorganics (i.e. glass and mineral particles) and processing additives to heavily oxidized, charred or crosslinked polymer. The most commonly observed gels contain polymer differing from the bulk of the sample in its melt viscosity, density or molecular weight.Polymeric gels are a special concern in polyethylene films. Over the years and with the examination of a variety of these samples three predominant polymeric species have been observed: density gels which have different crystallinity than the film; melt-index gels in which the molecular weight is different than the film and crosslinked gels which are comprised of crosslinked polyethylene.

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CHEMICAL EFFECTS IN MULTIELECTRON PROCESSES IN THE FLUORIDE ANION

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19879136 ◽

1987 ◽

Vol 48 (C9) ◽

pp. C9-777-C9-780

Author(s):

R. HESSABI ◽

D. URCH

Keyword(s):

Fluoride Anion ◽

Chemical Effects

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Synthesis of nickel selenites, their solubility and bonding in them

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19822069 ◽

1982 ◽

Vol 47 (8) ◽

pp. 2069-2076 ◽

Cited By ~ 10

Author(s):

Miroslav Ebert ◽

Zdeněk Mička ◽

Ilona Peková

Keyword(s):

Magnetic Properties ◽

Hydrogen Bonding ◽

Solubility Diagram ◽

Reflectance Spectroscopy ◽

Chloride Anion ◽

Fluoride Anion ◽

Infrared Absorption Spectroscopy ◽

Magnetic Parameters ◽

Nickel Cation ◽

Spectrochemical Series

The solubility diagram of the NiSeO3-SeO2-H2O system at 25 °C was studied, and on its basis, Ni(HSeO3)2.2 H2O was prepared. This selenite and NiSeO3.2 H2O were investigated by infrared absorption spectroscopy and by electronic reflectance spectroscopy and their magnetic properties were determined. Based on the infrared spectra, the force constants of the selenium-oxygen bonds were determined and the hydrogen bonding was characterized. The electronic reflectance spectra and the magnetic parameters indicate an octahedral arrangement of the coordination sphere of the nickel cation and characterize the selenite anion as a ligand that in the spectrochemical series assumes a position between the fluoride anion and water and in the nephelauxetic series, between ethylenediamine and the chloride anion.

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Cleavage of the Epimines of 1,6-Anhydrohexoses with Fluoride Anion

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20052075 ◽

2005 ◽

Vol 70 (12) ◽

pp. 2075-2085 ◽

Cited By ~ 5

Author(s):

Jiří Kroutil ◽

Klára Jeništová

Keyword(s):

Fluoride Anion ◽

Ring Cleavage ◽

Protecting Group ◽

Reaction Conditions ◽

Aziridine Ring ◽

Cleavage Reactions ◽

Derivatives Of ◽

Fluoro Derivatives

Aziridine ring cleavage reactions of five N-nosylepimines (2-6) having D-talo, D-galacto, D-manno, and D-allo configurations with potassium hydrogendifluoride under various reaction conditions have been performed. The cleavage regioselectively afforded diaxial isomers of vicinal amino-fluoro derivatives of 1,6-anhydro-β-D-gluco- and mannopyranose 7-11 in 51-94% yields. Removal of 2-nitrobenzenesulfonyl protecting group with benzenethiol has been attempted in the case of compound 10.

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