To Triethylamine Research Articles

Transformation of carbon-encapsulated metallic Co into ultrafine Co/CoO nanoparticles exposed on N-doped graphitic carbon for high-performance rechargeable zinc-air battery

In this work, Co-MOFs microrod structures were firstly fabricated using Co2+ source and trimesic acid (H3BTC) as reaction precursors by a simple solvothermal method, followed by pyrolysis treatment at 900 °C in N2 atmosphere to obtain metallic Co encapsulated into graphitic carbon structure (Co@C) with an average Co particle size of 7.7 ± 0.2 nm excluding large-sized Co particles (>20 nm) and a surface area of 184 g cm−2. Interestingly, ultrafine Co/CoO nanoparticles with an average size of 1.8 ± 0.2 nm anchored on graphitic carbon surface (Co/CoO-C) can be obtained through further acid/alkali rinsing treatment of the as-prepared Co@C using HNO3 and NH3·H2O aqueous solutions respectively, followed by thermal treatment at 900 °C in N2 atmosphere. The formation of Co/CoO-C with a surface area of 247 g cm−2 can be ascribed to the dissolution and reorganization process of carbon-encapsulated metallic Co under acid/alkali rinsing and post-thermal-treatment conditions. As the electrocatalyst, Co/CoO-C exhibits superior bifunctional electrocatalytic activities of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline media, notably better than ORR and OER activities of Co@C. The characterization results show that Co-Nx and N doping can be found in both Co@C and Co/CoO-C due to triethylamine (TEA) as solvent providing N source during Co-MOFs synthesis, which are catalytic active species toward electrocatalytic oxygen reactions. Furthermore, the highly exposed ultrafine Co/CoO on graphitic carbon surface can provide more catalytic active sites for high-performance ORR and OER, while carbon-encapsulated metallic Co in Co@C is incapable of directly contacting the electrolyte (only influencing shell-layer carbon function work) with limitedly improved electrocatalytic performance. The fabricated Co/CoO-C with superior bifunctional ORR and OER activities as air cathode material was assembled into a rechargeable zinc-air battery, exhibiting high power density and long-term stability. Our work provides an approach to transform low catalytic active electrocatalyst to high catalytic active one for renewable energy applications.

New non-traditional organogelator of β-diketone-boron difluoride complexes with terminal tetraphenylethene: Self-assembling and fluorescent sensory properties towards amines

New β-diketone-boron difluoride complexes functionalized with tetraphenylethene (TPEB, DTPEB and TTPEB) which exhibit AIE (aggregation-induced emission) properties have been synthesized. It was found that only boomerang-shaped DTPEB without any traditional gelation groups could form organogel in specific organic solvents. It gave strong orange red fluorescence in organogel as well as in xerogel-based film although it was non-emissive in solution. It is interesting that the emission of DTPEB in xerogel-based film could be quenched significantly upon exposure to triethylamine (TEA) vapour, and the detection limit was as low as ca. 0.1 ppb. This work provides a strategy for the synthesis of a new rigid non-traditional π-gelator via the construction of a boomerang-shaped π-conjugated skeleton. In addition, the gelation of the π-gelators with AIE ability is a facile method for the fabrication of luminescent organic nanomaterials.

Preparation of conducting films based on α-MoO3/PANI hybrids and their sensing properties to triethylamine at room temperature

A smart sensor based on α-MoO3/PANI hybrids was fabricated by loading α-MoO3 nanorods on polyethylene terephthalate (PET) thin film as a building framework and then the PANI was covered on the framework via in-situ chemical oxidation polymerization. The morphology and structure of the hybrids have been characterized by XRD, SEM, TEM and XPS etc. The sensor shows high sensitivity and good selectivity to triethylamine (TEA), and exhibits linear response to TEA concentration from 10 to 100ppm at room temperature. The sensing mechanism of α-MoO3 enhancing PANI response to TEA has also been discussed in detail, which is attributed to the well-defined morphology and formation of p-n heterojunctions at interface of hybrid. The study will open a new window for development of a high sensitive and portable sensor to online detect VOCs at room temperature.

Highly sensitive and selective volatile organic amine (VOA) sensors using mesoporous WO3–SnO2 nanohybrids

Considering the tremendous toxic effect on human well being and environment, the qualitative and quantitative determination of volatile organic amines (VOAs) is of significant importance. In this paper, nanostructures of WO3–SnO2 having large surface area and uniform pore channels were produced using mesoporous silica, SBA-15 as hard template using a nanocasting strategy. Sensors based on mesoporous WO3–SnO2 nanohybrids were fabricated for detection of important biological odor markers including triethylamine, ethylenediamine, ethanolamine, cyclohexylamine gases. The results exhibit that mesoporous WO3–SnO2 are highly sensitive and distinctly selective to triethylamine (TEA). The response (Ra/Rg) of this sensor to 50ppm TEA was 87 with a fast response and recovery times of 6 and 7s respectively at the operating temperature of 220°C. The detection limit can also be as low as 1ppm-level with a response of 3. Besides, the sensor shows excellent response/recovery and stability in the concentrations ranging from 1 to 500ppm. These high sensing performances mainly attribute to the formation of unique heterojunction at the WO3–SnO2 interface and the presence of intrinsic high surface area supported by mesopores arrangement, which collectively offers great variation of resistance in air and TEA molecules (heterojunction) alongside facilitating the faster propagation and adsorption/desorption of TEA molecules across the sensor surface (mesoporous structure). Thus, the nanocasted mesoporous material provides an effective and efficient strategy to design new TEA gas sensors.

Highly selective low-temperature triethylamine sensor based on Ag/Cr2O3 mesoporous microspheres

Cr2O3 mesoporous microspheres were synthesized via an ethanol solvothermal process and Ag/Cr2O3 microspheres were prepared by a surfactant-modified method. The two products were characterized by XRD, EDX, XPS, TEM and HRTEM techniques. The diameter of Cr2O3 microspheres was 1–1.5μm, which were further constructed by the building blocks of nanoplates. The Ag/Cr2O3 microspheres kept the morphology and mesoporous structure of Cr2O3 microspheres and Ag nanoparticles were successfully deposited on the surface of Cr2O3 microspheres with the particle size of 7–25nm. The gas sensing properties of the Cr2O3 and Ag/Cr2O3 microspheres to triethylamine (TEA) were measured at different working temperatures. The response of Cr2O3 microspheres to 50ppm TEA was 15.2 at working temperature of 170°C, while that of Ag/Cr2O3 increased to 52.9 at a lower temperature of 92°C. The modification of Ag nanoparticles not only greatly lowered the optimum working temperature, enhanced the response of Cr2O3 microspheres to TEA gas, but also further improved the selectivity of the sensor to TEA. The significant improvement of Ag/Cr2O3 microspheres to TEA gas sensing property could be attributed to the modified Ag sensitization and catalytic effect, and mesoporous structure of Cr2O3 microspheres.

Construction of three-dimensional flower-like α-MoO3 with hierarchical structure for highly selective triethylamine sensor

Novel flower-like α-MoO3 with hierarchical structure was synthesized via a facile solvothermal route without any surfactant or template, and subsequent calcination at 400°C in air for 2h. The α-MoO3 flowers with the diameters about 3–5μm consist of microrods with average diameters of 150–200nm growing radially from the center of the hierarchical flower-like structure, and the microrods are assembled from nanoplates. The sensors based on α-MoO3 flowers are highly sensitive and distinctively selective to triethylamine (TEA). The response of this sensor to 100ppm TEA attains 416 and the detection limit is 0.5ppm at the operating temperature of 250°C. The change of the surface status of α-MoO3 flowers before and after exposure to TEA at 250°C was investigated by using XPS technique and the TEA sensing mechanism over α-MoO3 was proposed.

Interaction of functionalized Ga 2O 3 NW-based room temperature gas sensors with different hydrocarbons

Ga 2O 3 nanowires (NWs) incorporated into capacitance-based room temperature gas sensors were functionalized with acetic and pyruvic acid (AC and PA, respectively) with the goal of achieving higher selectivity toward different groups of hydrocarbons. Fourier transform infrared spectroscopy (FTIR) was used to determine the geometry of the resulting adsorbate complexes. A bridge-like geometry was observed for adsorbed AC and a mixture of different geometries for PA, some of which had hydrogen-bonded OH groups. In addition, FTIR studies showed evidence of the enolic form of PA adsorbed on the surface. The AC-functionalized NWs showed a significant decrease in response to such common analytes as acetone and nitromethane as well as to triethylamine (TEA). In the case of PA-functionalized NWs, no response was observed to nitromethane, however, the response to TEA increased one order of magnitude compared to the bare NWs. FTIR spectroscopy was used to obtain more insight into the mechanism of interaction of AC- and PA-functionalized NWs with these analytes. This work demonstrates the use of a bifunctional molecule (PA) to modify the response of an oxide sensor in a way that a monofunctional molecule (AC) cannot. A significant result of this work is that the functionalization chemistry does not presume the existence of OH groups on the initial oxide surface.

Preparation of one-dimensional (1D) polyaniline–polypyrrole coaxial nanofibers and their application in gas sensor

A facile and low-cost method has been developed to prepare one-dimensional (1D) polyaniline–polypyrrole (PANI–PPy) coaxial nanofibers (PPCF). The morphology and molecular structure of PPCF were proved by scanning electron microscopy, transmission electron microscopy, EDX, UV–vis, FTIR and Raman spectroscopy. A possible synthetic scheme for the synthesis of PPCF has been proposed. The electrical responses of PPCF to triethylamine (TEA) vapor were measured at room temperature. It was found that PPCF showed a rapid, sensitive and reversible conductance change upon exposure to TEA vapor at concentrations ranging from 1 to 1000 ppm. The results suggested that the comprehensive performance of the gas sensor using PPCF was better than the results obtained using PANI nanofibers and PPy separately. In addition, a sensing mechanism was proposed.

Optical sensing of triethylamine using CdSe aerogels

The photoluminescence (PL) response of highly porous CdSe aerogels to triethylamine (TEA) isinvestigated and compared to results from prior studies on single crystals andnanoparticle–polymer composites. As-prepared CdSe aerogels show significant andreversible enhancement of luminescence intensity upon exposure to TEA relative to theintensity in pure argon carrier gas. The enhancement in the PL response is dependenton the concentration and linear over the range of TEA concentration studied (4.7 × 103–75 × 103 ppm).The sensing response of previously tested samples exhibits saturation behavior that is modeledusing Langmuir adsorption isotherms, yielding adsorption equilibrium constants in the range 300–380 atm − 1. The response is sensitively affected by the surface characteristics of the aerogel; when thewet gels are treated with pyridine prior to aerogel formation, the response to TEA isdiminished, and when as-prepared aerogels are heated in a vacuum, no subsequentresponse is observed. Deactivation is attributed to an increase in surface oxide (SeO2) and decreasein surface Cd2 + Lewis acid sites. Sensing runs of approximately one hour have little impact on themorphology or crystallinity of the aerogels, but do result in partial removal of residualthiolate ligands left over from the gelation process.

Contrast sensitivity measurement in evaluations of visual symptoms caused by exposure to triethylamine.

OBJECTIVES: To determine whether blurred vision caused by exposure to triethylamine (TEA) can be detected by the measurement of contrast sensitivity. METHODS: 41 cold box core makers of three foundries...

Mass identification of negative ions in excimer-laser-irradiated triethylamine: atomic rearrangements in electron attachment to highly excited states

Efficient negative-ion formation via electron attachment to triethylamine (TEA) laser-excited to energies above its ionization potential had been reported; however, the evidence for negative-ion formation was indirect, and the identities of the negative ions were not known. In this Letter, we describe an apparatus where the negative (and positive) ions produced in a gas cell via laser irradiation can be extracted to a time-of-flight mass spectrometer for mass identification and present the results obtained for excimer-laser-irradiated TEA. It is shown that extensive atomic rearrangements can occur in dissociative electron attachment to highly excited states of polyatomic molecules.

Effects of ethanol ingestion and urinary acidity on the metabolism of triethylamine in man

In four volunteers exposed to triethylamine (TEA) by inhalation (20 mg/m3, 8 h), the nonrenal clearance of TEA into triethylamine-N-oxide (TEAO) was inhibited by 15 to 30% by intake of ethanol (blood serum level in average 25 mmol/l). Ethanol intake caused a decrease of plasma levels of TEA and TEAO, and of the fractional formation of TEAO. This may partly be due to a second effect of ethanol; it caused a slight decrease of urinary pH, which led to an increase of the urinary TEA excretion rate, with a possible withdrawal of TEA from oxygenation. Indeed, this effect was efficiently counteracted by intake of sodium bicarbonate, which caused a decrease of renal clearance of TEA, and increases of plasma levels of TEA and TEAO, and of the fractional formation of TEAO. A change of urinary pH by about two units caused a change of renal clearance of TEA by a factor of three and of the oxygenation by two. The renal clearance of TEAO was not affected by urinary pH.

Metabolism of triethylamine in polyurethane foam manufacturing workers.

In 20 workers studied before, during, and after exposure to triethylamine (TEA) in a polyurethane-foam producing plant the amount of TEA and its metabolite triethylamine-N-oxide (TEAO) excreted in urine corresponded to an average of 80% of the inhaled amount. An average of 27% was TEAO, but with a pronounced interindividual variation. Older subjects excreted more than younger ones; less than 0.3% was excreted as diethylamine. The data indicate half-lives for TEA and TEAO excretion in urine of about 3 hr. The postshift level of TEA in urine and plasma are good indicators of the time-weighted average air level during the preceding work day, and might thus be used for biological monitoring. An air level of 10 mg/m3 (proposed occupational standard) corresponds to a urinary excretion of 65 mmol TEA/mol creatinine and a plasma level of 1.9 mumol/liter (biological exposure indices).

Disruption of antennal morphogenesis in Bracon hebetor by exposure to triethylamine

AbstractExposing third instar larvae of the wasp Bracon hebetor to triethylamine (TEA) results in malformed antennae in eclosing adults. The purpose of this research was to examine the effects of TEA at the cellular level. Rate of growth of treated antennal buds (56–76 h) and mean size (76–96 h) were significantly reduced. Internal pH was elevated for 5 h after TEA exposure. Cell size remained constant except in treated buds from 76 to 96 h, when diameter was reduced. The mean mitotic index (MI) was reduced and a normal peak at 72–76 h was eliminated. Cell death (DI) increased. Increased DI and decreased MI from 0 to 5 hours after exposure are attributed to increased pH. TEA can form reactive alkylating intermediates, and loss of the MI peak 12 h after exposure accompanied by increased DI may be due to alkylation. It is concluded that the reduced number of segments is due to an overall reduction in total number of cells. Abnormal segmentation may involve alkylation induced somatic mutations.

Detection of VUV photons with a photoionization proportional scintillation chamber

The VUV emission of Ar and Kr filled proportional scintillation counters (GSPC) has been detected by a gaseous photoionization detector with multianode proportional chamber configuration. Transfer efficiencies were measured for several photoionizing gases, and values of 30% and 41% were obtained for di- n-propylamine and di-iso-propylamine relatively to triethylamine (TEA) for the detection of Kr emission, and values of 61% and 47% were obtained for acetylacetone and cyclohexene relatively to benzene for the detection of Ar emission. Cross sections for photoabsorption were calculated from the experimental data: σ (TEA) ∼ 9 Mb (or σP ∼ 450 Mb · Torr , P being the vapour pressure at room temperature), σP (di-n-propy lamine) ∼ 400 Mb · Torr, σP (di-iso-propylamine) ∼ 1500 Mb · Torr, σP (acetylacetone) ∼ 200 Mb · Toor, σP (cyclohexene) ∼ 10 3 Mb · Torr. Threshold fields for secondary light production were obtained as (0.92±0.02) V · cm − · Torr −1 and (0.77±0.02) V · cm −1 · Torr −1 for Ar and Kr respectively. Measurements of energy and spatial resolution, though of a preliminary nature, were undertaken.