High Molecular Amines Research Articles

Cr-doped α-MoO3 nanorods for the fast detection of triethylamine using a pulse-heating strategy

Triethylamine (TEA), a high-molecular amine, has a terrible desorption rate on oxide surfaces, and it remains a challenge to develop a rapid response sensor to detect it. Herein, Cr-doped α-MoO3 nanorods have been prepared through a grinding and subsequent annealing route. The microstructure of the as-obtained Cr-doped α-MoO3 nanorods was determined using various analysis techniques. Sensing experiments showed that the Cr-doped α-MoO3 nanorods exhibit a significant response for TEA, with actual concentrations as low as 1 ppm at 200 °C. Moreover, the sensor can be completely recovered after a TEA-sensing event in less than 2 min using pulse-heating at 300 °C in air. In addition, an ultrahigh selectivity for TEA against other vapors was observed. This doping method, combined with a pulse-heating technique, may act as an efficient strategy for designing a high-performance gas sensor.

Influence of high molecular amines on removal of nitrates from aqueous solutions by the nanofiltration method

The removal of nitrate ions from aqueous solutions using OPMN-P membranes in the presence of high-molecular amines, such as polyhexamethylene guanidine and aethonium was studied. It was shown that within the range of pH 4–7 the five-fold weight excess of amines makes possible to increase retention of nitrate ions up to 0.83 in case of polyhexamethylene guanidine and up to 0.76 in the case of aethonium. The influence of chlorides on the treatment process was also investigated. The interaction mechanisms in the “membrane-high molecular amine-nitrates” system were discussed.

Atomic absorption spectrophotometric analysis of antimony iodide complex extraction with high molecular amine

Atomic absorption spectrophotometric analysis of antimony iodide complex extraction with high molecular amine

Atomic absorption spectrophotometric analysis of Cr (VI) in the waste water from plating by using high molecular amines as extracting reagents

The solvent extraction method is used for separating Cr(III) and Cr(VI), which are determined by means of atomic absorption spectrophotometry. In this paper, the use of high molecular amines-xylene solutions was investigated for extracting Cr(VI). Cr(VI) was extracted with HCl-acidified 1% Amberlite LA-1-xylene solution. After separating the organic phase, Cr(VI) in the phase was determined by atomic absorption spectrophotometry at 3579 Å in air-C2H2 flame. The calibration curve is linear for less than 100 μg of Cr(VI). Cr(III), Zn, Cu, Fe(III), Ni, and Mn(II) do not affect the determination in their amount of less than 1000 μg. Pb interferes with it in the amount of 10 μg. The standard deviation of absorbances, which was measured 5 times, was 0.005 with the waste water from plating.

The analysis of polyethylenepolyamines by NMR and infrared spectroscopy

The infrared spectraof the polyamines were studied on a UR-20 spectrometer in the frequency range 400-4000 cm -i. We recorded the spectra of the substances in their natural liquid state in K]3r cells (the low-molecular amines were studied at a fixed cell thickness of 0.028 ram, and the high-molecular amines were studied in the form of thin films). To detect the effect of intermoleeular interaction, we also recorded the infrared spectra of the solutions in carbon tetraehloride. The data for the solutions, and the physieochemieal characteristics of the polyethylenepolyamines studied, were given in [2]. Figures 1 and 2 give the infrared spectra of the two model compounds diethylamine andtriethylamine, and of technical fractions of polyethylenepolyamine homologs from the mono- to the tetra-derivative. The secondary amine group is revealed in the infrared spectrum of diethylamine by the corresponding bands due to the stretching (3287 and 3380 cm -i) and bending (1650 era -I) vibrations of the N-H bonds. The spectrum of diethylamine is also characterized by an intense band at 1143 cm -i, corresponding to the C-N-C group.

Extraction of chloride complexes of niobium by high-molecular alkylamines

1. A systematic study was made of the extraction of chloride complexes of niobium from hydrochloric acid solutions with solutions of high-molecular amines. The influence of the class of the amine, the concentration of the acid, metal, and amine, and the nature of the solvent on the distribution coefficient of niobium was investigated. 2. Most solutions (0.1 M) of the investigated secondary and tertiary amines in carbon tetrachloride extract niobium from 8–10 M hydrochloric acid to an extent of 93–95%. Evidently the compound (AmH)2 ·NbOCl5 passes into the organic phase.

Solubility and activity of high-molecular amine hydrochlorides in organic solvents

Crystalline long-chain aliphatic primary, secondary and tertiary amine hydrochlorides ranging from C 6 to C 12 in the alkyl chain were prepared and their solubilities in various non-polar, water immiscible organic solvents determined at 25°. The solubility parameters of amine hydrochlorides evaluated were used to calculate their activity coefficients in a number of solvents on the assumption that the systems satisfy the requirements of the concept of regular solutions. The deviations of systems from ideal behaviour are discussed in terms of molecular association of the solutes. The information is related to solvent extraction studies involving these solutes.