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A highly selective and simple fluorimetric liquid chromatographic method for the determination of triethylenetetramine (TETA), a therapeutic drug for Wilson's disease, in human and rabbit sera is described. This method is based on...
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A highly selective and simple fluorimetric liquid chromatographic method for the determination of triethylenetetramine (TETA), a therapeutic drug for Wilson's disease, in human and rabbit sera is described. This method is based on intramolecular excimer-forming fluorescence derivatization, which allows spectrofluorometric discrimination of polyamino compounds from monoamino species, followed by liquid chromatography. TETA and 1,6-hexanediamine (internal standard) were converted to the corresponding excimer-forming derivatives with a pyrene reagent, 4-(1-pyrene)butyric acid N-hydroxysuccinimide ester. The derivatives were separated within 20 min on a reversed-phase column using isocratic elution and detected spectofluorometrically at 480 nm with excitation at 345 nm. This method was successfully applied to the monitoring of TETA in human and rabbit sera with a simple pretreatment. The detection limit for TETA in serum was 18 ng/ml (0.13 nmol/ml) corresponding to 0.2 pmol on column at a signal-to-noise ratio of 3.
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New epoxidized soybean oil (ESO)/clay nanocomposites have been prepared with triethylenetetramine (TETA) as a curing agent.The dispersion of the clay layers is investigated by X-ray diffraction (XRD) and transmission electron micr...
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New epoxidized soybean oil (ESO)/clay nanocomposites have been prepared with triethylenetetramine (TETA) as a curing agent.The dispersion of the clay layers is investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM).XRD and TEM data reveal the intercalated structure of ESO/clay nanocomposites has been developed.The thermogravimetric analysis exhibits that the ESO/clay nanocomposites are thermally stable at temperatures lower than 180 deg C,with the maximum weight loss rate after 325 deg C.The glass transition temperature,Tg,about 7.5 deg C measured by differential scanning calorimetry (DSC) and T_g about 20 deg C measured by dynamic mechanical study have-been obtained.The difference in the T_g between DSC and dynamic measurements may be caused by different heating rate.The nanocomposites with 5-10 wt% clay content possess storage modulus ranging from 2.0 X 106 to 2.70 X10~6 Pa at 30 deg C.The Young's modulus (E) of these materials varies from 1.20 to 3.64 MPa with clay content ranging from 0 to 10 wt%.The ratio of epoxy (ESO) to hydrogen (amino group of TETA) greatly affects dynamic and tensile mechanical properties.At higher amount of TETA,the nanocomposites exhibit stronger tensile and dynamic properties.
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Tetraaza Schiff base macrocyclic ligands, L~1,L~2 and their transition metal chelates have been synthesized and characterized by elemental analyses, IR, electronic, EPR and ~1H NMR spectra, TGA and magnetic measurements. The molar...
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Tetraaza Schiff base macrocyclic ligands, L~1,L~2 and their transition metal chelates have been synthesized and characterized by elemental analyses, IR, electronic, EPR and ~1H NMR spectra, TGA and magnetic measurements. The molar conductance of one milli-molar solution of the complexes measured in DMF indicates that the divalent metal complexes are nonelectrolyte while those of trivalent metal ion, are 1:1 electrolytic in the same solvent. The reduction of Racah parameter from the free ion value confirms the presence of considerable covalence of metal ligand sigma bond in the Co(II) and Mn(II) complexes. The EPR spectra of Cu(II) complexes at room temperature shows axial symmetry indicating a d_x~2-_y~2 ground state with significant covalent character. The thermal analysis suggests that the complexes do not contain water molecules because only the metal is left as residue.
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A triethylenetetramine epoxy mixture was synthesized through the reaction of a low-molecular-weight liquid epoxy resin with triethylenetetramine (TETA). Then triethyltetramine (TETA) was injected dropwise into a propylene glycol m...
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A triethylenetetramine epoxy mixture was synthesized through the reaction of a low-molecular-weight liquid epoxy resin with triethylenetetramine (TETA). Then triethyltetramine (TETA) was injected dropwise into a propylene glycol methyl ether (PM) solution for chain extension reaction. A hydrophilic and flexible polyether segment was introduced into the hardener molecule. The effects of TETA/DGEPG, reaction temperature and reaction time on the epoxy conversion of polyethylene glycol diglycidyl ether (DGEPG) were studied. In addition, several alternate strategies to add epoxy resin to the high-speed dispersion machine and synthesize MEA DGEBA adduct (without catalyst and with bisphenol A diglycidyl ether epoxy resin) were compared. It was found that the higher the molecular weight of triethylenetetramine, the longer the chain segment of the surface active molecule. When the equivalence ratio of amine hydrogen and epoxy group is low, the stability of lotion is good. When the ratio of amine hydrogen to epoxy group is large, the content of triethylenetetramine is small. The main objective of this study is the provision of new data and knowledge for the development of new materials in the coating and electronic industry.
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Solar photocatalytic process has been shown to be an energy effective and eco-friendly degradation of unwanted pollutants present in the industrial wastewater. The present study introduces the preparation and characterization of n...
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Solar photocatalytic process has been shown to be an energy effective and eco-friendly degradation of unwanted pollutants present in the industrial wastewater. The present study introduces the preparation and characterization of novel holmium vanadate (HoVO4) nanostructures that fully used in the photodegradation efficiency of anionic and cationic organic pollutants. HoVO4 synthesized via a sonochemical-assisted route and triethylenetetramine (TETA) was used as a capping and precipitation agent. The experiments were carried out under a probe as sonication source, and its power was adjusted in 30 W (9 kHz), 50 W (15 kHz) and 80 W (24 kHz) for different samples. The obtained nanostructures were characterized by surface analytical and spectral techniques includes XRD, FT-IR, SEM, TEM and UV-visible spectra measurements. The HR-SEM images reveal that HoVO4 exists as a spindle-shape with spherical morphology together. HR-TEM images reveal that prepared catalyst has a spherical structure with uniform particle size. The results outline 67.6% elimination of methyl violet dye within 90 min under UV light in the presence of the optimal nano-sized formulation of 24.5 nm size. The prepared photocatalyst possesses high stability and reusability without appreciable loss of catalytic activity up to three runs.
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Uptake of metals, organics, and formation of metal-organic complexes on the surface or in the interlayer of clay minerals had been studied extensively over the last half century. In this study, we investigated the uptake mechanism...
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Uptake of metals, organics, and formation of metal-organic complexes on the surface or in the interlayer of clay minerals had been studied extensively over the last half century. In this study, we investigated the uptake mechanisms of Cu2+, triethylenetetramine (TETA), and Cu-TETA on rectorite and its use for metal removal via metal-TETA complexation. The uptake of Cu2+, TETA, and Cu-TETA by rectorite occurred on the external as well as in the interlayer space, resulting in a change of d(001)-spacing due to differences in sizes of interlayer cations or complexes. Although the uptake of Cu2+ and Cu-TETA by rectorite was via a cation exchange process as evidenced by the stoichiometric desorption of dominant interlayer cation Ca2+, the uptake of TETA alone on rectorite was via complexation with interlayer cation Ca2+. Due to strong affinity of TETA for Cu2+, significant amounts of Cu2+ uptake occurred on TETA-rectorite. Desorption of Ca2+ from TETA-rectorite confirmed the replacement of interlayer cation Ca2+ by Cu2+. However, the replacement of Ca2+ by Cu2+ in TETA-rectorite did not involved in removal of TETA. As such, TETA-modified clay minerals may serve as a type of sorbents for the removal of selected heavy metals via surface or interlayer via complexation.
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Among chelating resins, the amine containing resins which have excellent adsorption property for metal ions are especially applied widely in separation, enrichment, and removing of heavy metal ions. In this paper, new amine contai...
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Among chelating resins, the amine containing resins which have excellent adsorption property for metal ions are especially applied widely in separation, enrichment, and removing of heavy metal ions. In this paper, new amine containing resins based on polyacrylonitrile (PAN-DTAand PAN-TETA) were prepared through the reactions of polyacrylonitrile with diethylenetriamine (DTA) or triethylenetetramine (TETA) by a rapid, simple, and economically feasible route. The prepared resins which are completely insoluble in water and common organic solvents were used to remove Ni(II) ion from aqueous solutions. The sorption behaviour of the resins for this ion showed that the greater sorption and distribution coefficients (K_d) were obtained at higher pH media. The highest sorptions of Ni(II) on PAN-DTA50, PAN-DTA100, PAN-TETA50 and PAN-TETA100 resins were determined as 1.9, 3.0, 1.8 and 2.9 mmol/g, respectively. It is shown that the amine capacity of the resins is dependent on the volume percentage of DTA or TETA and the maximum capacity of amines obtained are 6.25 and 9.0 mmol/g for PAN-DTA100 and PAN-TETA100, respectively. Also, the recovery of Ni(II) from PAN-TETA50 and PAN-TETA100 resins are estimated about 65% and 61%, respectively. The resins and their metal complexes are studied by FTIR spectroscopy, scanning electronic microscopy (SEM), and thermal gravimetric analysis (TGA). All the analytical methods have confirmed the presence of metal in the metal-resin complexes.
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The latency of toxic cations in the ecosystem poses serious ecological problems due to its bioaccumulation potential and toxicity to living organisms. The effective removal of these wastewater cations releasing from multi-industri...
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The latency of toxic cations in the ecosystem poses serious ecological problems due to its bioaccumulation potential and toxicity to living organisms. The effective removal of these wastewater cations releasing from multi-industries is a bottleneck issue. Therefore, an attempt has been made to design a suitable sorbent for cations sorption from the aqueous environment. The chitosan biopolymer was modified with triethylenetetramine to incorporate active sites in the polymeric sequence to boost up its cations sorption capacity. Triethylenetetramine molecule anchoring chitosan (CH-TET) was authenticated through elemental assay, Fourier-transform infrared spectroscopy and C-13 NMR in solid-state, scanning electron microscopy and thermal analysis. The sorption of lead (1.94 mmol g(-1)), copper (2.79 mmol g(-1)) and nickel (1.53 mmol g(-1)) was carried out using the functionalized chitosan from aqueous solution, which showed higher sorption capacity for lead and copper than the pristine chitosan in terms of Langmuir sorption isotherm. To scrutinize the mechanism of sorption and energy of interaction between sorbent and sorbate, Langmuir, Temkin, and Freundlich isotherm models were used for sorption study. The Langmuir model showed the best fitting to the results based on lower error function values and a higher correlation coefficient (R-2). It can be concluded that the triethylenetetramine-modified chitosan might be considered as an effective sorbent for cations removal from industrial wastewater. (C) 2020 Elsevier B.V. All rights reserved.
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In this study, we report preparation of epoxidized soybean oil (ESO)-based "green" composites and nanocomposites. The high strength and stiffness composites and nanocomposites are formed through flax fiber and organoclay reinforce...
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In this study, we report preparation of epoxidized soybean oil (ESO)-based "green" composites and nanocomposites. The high strength and stiffness composites and nanocomposites are formed through flax fiber and organoclay reinforcement. The epoxy resin, 1,1,1-tris(p-hydroxyphenyl)ethane triglycidyl ether (THPE-GE) is used as a co-matrix for flax fiber-reinforced composites. For the clay-reinforced nanocomposites, the dispersion of the clay layers is investigated by X-ray diffraction (XRD) and by transmission electron microscopy (TEM). XRD and TEM data reveal that the intercalated structure of ESO/clay nanocomposites has been developed. Mechanical properties of both materials are investigated. As curing agent, triethylenetetramine (TETA) is used for both systems.
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A three-variable and two-level (2~3) factorial study was used to assess simultaneous effects of TETA, EDTA and KAX on pentlandite and pyrrhotite in flotation of a severely oxidized nickel-copper sulphide ore. The main effects of t...
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A three-variable and two-level (2~3) factorial study was used to assess simultaneous effects of TETA, EDTA and KAX on pentlandite and pyrrhotite in flotation of a severely oxidized nickel-copper sulphide ore. The main effects of these reagents on recovery of pentlandite and pyrrhotite were consistently negative, positive and positive, respectively. The approach used is novel in that the factorial analysis was carried out for every stage of flotation recoveries cumulatively. This revealed how statistical significance of the reagent effects varies with the progress of flotation. For example, the effect of KAX as a collector was not significant in the initial period of flotation, suggesting that these minerals were mostly relying on their self-induced floatability due to involvement of a metastable form of sulphur. This occurred to a much greater extent for pyrrhotite, accounting for 82 percent of floatable pyrrhotite compared to 22 percent of floatable pentlandite. Presence of elemental sulphur as well as metal ions was established by extraction studies. Separation efficiency between pentlandite and pyrrhotite was generally poor due to similar characteristics induced by oxidation.
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