ammonium group

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ammonium group,

in chemistry, a positively charged nitrogen atom joined by single bonds to four other atoms or groups. The simplest ammonium group, NH4+, is formed by protonationprotonation
, in chemistry, addition of a proton to an atom, molecule, or ion. The proton is the nucleus of the hydrogen atom; the positive hydrogen ion, H+, consists of a single proton.
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 of ammoniaammonia,
chemical compound, NH3, colorless gas that is about one half as dense as air at ordinary temperatures and pressures. It has a characteristic pungent, penetrating odor.
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, NH3, e.g., by its reaction with hydrogen chloride, HCl, to form ammonium chloride, NH4Cl, an ammonium compound. Organic ammonium compounds are formed by the reaction of an alkyl halide with an amine (see amino groupamino group,
in chemistry, functional group that consists of a nitrogen atom attached by single bonds to hydrogen atoms, alkyl groups, aryl groups, or a combination of these three. An organic compound that contains an amino group is called an amine.
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), for example, ethyl chloride, C2H5Cl, reacts with triethylamine, (C2H5)3N, to form tetraethyl ammonium chloride, (C2H5)4N+Cl. They are also formed by reaction of an amine with a mineral acid or by reaction of an alkyl halide with ammonia.
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In addition, the copolymer composite membranes exhibited a start decomposition temperature from 140 to 180[degrees]C, which was attributed to the evaporation of quaternary ammonium group. The small mass loss in the range of 180-355[degrees]C was deemed to the decay of aliphatic side chain.
The signal at 3.14 ppm was attributed to nine protons of the three methyl substitutes on the quaternary ammonium group. A characteristic strong signal observed at 3.89 ppm corresponds to the proton of the OS[O.sub.3]CH group coupled with one from a methylene group.
On the one hand, the incorporation of LDH sheets reduces the water uptake, which results in higher effective concentration of quaternary ammonium groups and consequently higher ionic conductivity.
The antimicrobial activity of several such modified PE samples was demonstrated and the presence of quaternary ammonium groups at the surface was confirmed.
A long, flat molecule -- a diammonium salt with a central, hydrophobic (water-avoiding) region flanked by charged ammonium groups -- serves as a template for the complex.
In this study, we used the cation exchange film contained the sulfonic acid groups and the anion exchange film contained the quaternary ammonium groups. Figure 2 show the diagrams for ion exchange on each films.