Influence Of Triethanolamine Research Articles

Influence of triethanolamine on mechanical strength and hydration performance of blended cement containing fly ash, limestone and slag

Triethanolamine (TEA) is known as a widely-used cement additive for regulating setting time, hydration process and mechanical strength. However, the working mechanism of TEA on blended cement with various kinds of minerals, has not yet thoroughly explored. This invesitigation focused on effects of TEA on the strength enhancement and hydration properties of the blended cementitious materials, containing fly ash, slag, limestone. Hydration heat evolution of the composite binder was studied by isothermal calorimetry. Pore size distribution was analyzed through mercury injection porosimetry (MIP), and the evolution of hydration products in the function of TEA was investigated by X-ray diffractometry (XRD), differential thermal analysis (DTA) and thermogravimetric analysis (TG). Microstructure and composition characteristics of hydration products were studied through scanning electron microscopy (SEM) equiped with energy dispersive X-ray spectroscopy (EDX). Results showed that strength enhancement effect of TEA varied when the component and proportion of cementitious materials altered. Containing 30% fly ash and 10% limestone, the composite binder got the optimal strength-enhancing effect to nearly 15%. When containing 30% slag and 10% fly ash, the composite binder obtained the worst strength-enhancing effect with about 5%. The addition of TEA prolonged the induction period, and enhanced the formation of AFt. With high aluminate glass phases, fly ash was vulnerable to be influenced by the complexation of TEA, and hence the pozzolanic reaction of fly ash was accelerated significantly, resulting in reduced content of Ca(OH)2 (CH) as well as increased production of hydrates. Limestone participated to accelerate the hydration of C3A, and provided microcrystals for the growth of hydrates. Slag was mainly composed of high calcium glass phases and was rarely impacted by the complexation of TEA. The findings would gain a comprehensive insight of TEA in affecting the hydration process of blended materials, and would provide expedient information on the technique to control the hydration progress of composite binder.

An investigation on effect of complexing agents on zirconium based ternary metal oxide nanoparticles by co-precipitation method

Wet chemical synthesis of Zirconium Bismuth Molybdate (ZBM) nano-particles and influence of Triethanolamine (TEA) and Tri Sodium Citrate (TSC) on various physical properties are highlighted in this work. Zirconium oxychloride, bismuth nitrate and sodium molybdate are used as reagents. Structural, optical, morphological and thermal properties of as prepared materials are characterized by XRD, SEM-EDAX, HR-TEM, UV–Vis–NIR spectroscopy, Photoluminescence spectroscopy, FTIR spectroscopy and TGA-DTA. X-ray Diffraction pattern confirms the formation of poly-crystalline zirconium bismuth molybdate with monoclinic ZrO2 phase and orthorhombic γ-Bi2MoO6. Crystallite size of all the samples fall in the range 16.097–26.278 nm. All the samples have maximum absorption in the UV region. The indirect band gap energy calculated from DRS spectra revealed ZBM has wide band gap in the range 2.592–2.982 eV and also an interesting phenomenon of line broadening of absorbance peak is observed under the influence of complexing agents. Formation of ZBM is further confirmed by FTIR spectra and purity of samples are revealed from EDAX spectra. TGA-DTA data indicated that ZBM with TSC has more thermal stability. Activation energy for thermal degradation process of the samples are studied by Coat–Redfern method, by assuming first order kinetics. Which shows that sample treated with TSC has more activation energy as compared to other samples indicating high thermal stability. Three PL emission peaks, one broad peak at Indigo-Blue and the others at Green wavelength region on UV excitation is observed on each sample, among which peak around the Indigo-blue region has maximum intensity. Emission peak intensity is higher for the sample treated with TSC and slight changes in intensity and peak positions is observed on the addition of TEA and TSC. A Characteristic blue shift in the emission spectra is observed for each sample treated with complexing agents.

The influence of Triethanol amine and ethylene glycol on the grindability, setting and hydration characteristics of Portland cement

Triethanol amine and ethylene glycol are used as grinding aids for Ordinary Portland Cement (OPC). Standard water of consistency, Blaine area, initial and final setting times and compressive strength are tested for OPC. The phase composition and microstructure of the formed hydrates are tested using DTA/TG and SEM techniques. Results showed that both the two GAs had a significant improvement in the performance of grinding mills. This is indicating by higher Blaine area when a dose of 0.03, 0.04 and 0.05wt. % are applied. Beside there are increase in the water demand (greater than 5%) for the all OPC mortar mixes admixed with triethanol amin or ethylene glycol at concentrations less than 0.05 wt.%. The improved hydration properties are reflected by an increase in the mechanical properties and microstructure of the mortar pastes admixed with the two GAs. This is with attributed to the increase in the cement fineness which leads to the progress in the degree of cement hydration.

The structure and the optical-electrical properties of the ZnO films and the Al:ZnO/N: ZnO homojunction photodiode

In this article, Al or N-doped ZnO films are prepared by wet chemical deposition method, and then the Al-ZnO/N-ZnO homojunction photodiode is structured. The influence of triethanolamine (TEA) content and deposition temperature on the structure, phase, and optical-electrical properties of N-ZnO films is investigated. The results of X-ray Diffraction (XRD) measurement show that the N-ZnO films have a hexagonal wurtzite structure with a preferred growth orientation along (002) crystal plane. The obvious Raman peak appeared at 436 cm−1 should be assigned to non-polar high-frequency E2H mode, which indicates the good crystallinity of N-ZnO film. The results of low temperature photoluminescence (LT-PL) measurement exhibit that the peak of UV emission, which shifts from 386 to 390 nm with the increase in measurement temperature from 50 to 250 K, may be mainly the exciton emission, coming from shallow donor Zni to valence band (Zni →VB: ΔE~3.15 eV) or conduction band to the shallow acceptor No (CB→No: ΔE~3.215 eV). Two visible emissions peaks may be attributed to the electron transitions from the single charged oxygen vacancies Vo+ and the double charged oxygen vacancies Vo++ defects, respectively. Three infrared emission peaks may be related to the electron transitions from the transition from deep donor level (Vo, Zni) to deep acceptor level (OZn) or the intra band transition between two states of Vo and Zni. For the response times of Al-ZnO/N-ZnO homojunction photodiode, the rise time (τr) is <2 ms and the decay time (τd) is about 22 ms. The value of responsivity (R) is calculated to be about 0.274 mA/W.

Influence of triethanolamine on cement pastes at early age of hydration

Accelerators (or activators) are commonly used as additives in cement to advance setting and/or hardening. Activation is often associated with the favoured hydration of particular cementitious phases, which can be induced by complexation mechanisms. However, the dispersion state of pastes with admixtures may also influence hydration rates. The aim of this paper is to highlight the correlation between mesostructural organisation and chemical reactivity of cement pastes with an additive. The affinity of triethanolamine (TEA), an activator molecule, with cement grains was assessed by measurement of total organic carbon. Moreover, the influence of the amine on the dispersion state, sedimentation kinetics and rheological behaviour was studied. Finally, X-ray diffraction, aluminium nuclear magnetic resonance spectroscopy and isothermal calorimetry were used in order to study the chemical reactivity of cement in the presence of the admixture. The combination of these granular and chemical characterisations helped to understand the mode of action of TEA.

Influence of Triethanolamine on Strength Development and Hydration of Cementitious Systems Blended with Titanium Slag

This paper investigates the influence of triethanolamine (TEA) on strength development and hydration of cement pastes and mortars incorporated with titanium slag (50% by mass of the total cementitious materials). The techniques including isothermal calorimetry, non-evaporative water content, and mercury intrusion porosimetry (MIP) were employed to characterize the hydration process at varied ages. The results show that: 1) 0.01%~0.10% addition of TEA has a positive effect on the strength development of blended cement mortars with titanium slag indicated by improved compressive strength and tensile strength; 2) TEA leads to an increase of hydration degree determined by measurement of isothermal calorimetry and non-evaporable water content before 28 d; 3) the cumulative porosity of cement pastes incorporated with titanium slag was reduced by TEA. Therefore, 0.01%~0.10% addition of TEA promotes the hydration of titanium slag, then forming more condensed structures, thus enhance the strength development of blended systems.

Influence of Triethanolamine on the Properties of Cement-Based Materials

The effects of triethanolamine on the compressive strength and setting time of fly ash cementitious materials, slag cementitious materials, and limestone cementitious materials were investigated. The results show that the dosage of 0.04% of triethanolamine can significantly improve the 3d, 7d and 28d compressive strength of fly ash cementitious materials. It possesses less impact on the setting time. The dosage of 0.04% of triethanolamine can significantly improve the 3d and 7d compressive strength of slag cementitious materials while the effect of late strength is not obvious. It extends the initial setting time and the final setting time is not changed, which has retarding effect. The results of hydration heat and XRD show that triethanolamine extends the induction period of cement hydration, and gypsum is exhausted in advance during the hydration process. Triethanolamine promotes the transformation of AFt to AFm and there is no effect on the type of hydration products.

Influence of triethanolamine in the deposition of Mn-doped ZnO thin films by the successive ionic layer adsorption and reaction process

The successive ionic layer adsorption and reaction method was used to prepare Mn-doped ZnO whose deposition was achieved by the complexation action of triethanolamine with Mn in the adsorption bath. The resulting films had the hexagonal wurtzite structure of ZnO with a remarkable poly-crystallization as consequence of the substitution of Mn in Zn sites, as confirmed by the X-ray Photoelectron Spectroscopy technique. The presence of Mn2+ and Mn4+ produced a change on the growth kinetics of the ZnO films. Undoped ZnO films were formed by flower-like particles. Meanwhile those doped with Mn were formed by the homogeneous distribution of packed spherical particles. These films were specular and had good optical transparency with average transmittances in the range of 79.26–83.35%. In addition, the optical band gap values of the Mn-doped ZnO films were in the range of 3.15–3.32 eV.

Influence of triethanolamine on the hydration product of portlandite in cement paste and the mechanism

The influences of triethanolamine (TEA) on the portlandite in hardened cement pastes (HCPs) were systematically investigated. Results show that the addition of TEA in cement pastes leads to a visible reduction of Ca(OH)2 (CH) content and considerably alters the morphology of CH crystals from large and parallel-stacked lamellar shape to smaller and distorted actinomorphic one. For the first time, the CH micro-crystals and even non-crystalline CH in HCPs were observed in the presence of TEA. Due to integration of CH micro-crystals in C–S–H phase, remarkable higher Ca/Si ratio of C–S–H phase was found. The formation of TEA-Ca2+complex via the interaction between Ca2+ and the oxygen atoms in TEA molecule was evidenced by the results of NMR and UV. It is believed that TEA can be introduced into the crystallization process of portlandite and thus significantly alters the morphology of CH crystals and even the content of the crystalline CH phase.

Mechanism of triethanolamine on Portland cement hydration process and microstructure characteristics

Influence of triethanolamine (TEA) on Portland cement hydration heat evolution process, hydration product, pore structure, setting time and concrete strength were investigated; and mechanism of TEA on the cement hydration process and microstructure is discussed. Research results indicate that TEA accelerates hydration process of C3A and retards that of C3S, such effects enhance with the increase of TEA dosage. TEA also promotes rate of AFt formation and its conversion to AFm. As a result, TEA accelerates setting of cement paste but jeopardizes strength of concrete. Depending on its dosage, TEA can either optimize or harm cement paste pore structure. The types of calcium sulfoaluminate hydrate (AFt or AFm) produced in cement paste containing TEA depends on the abundance of calcium sulfate, before depletion of calcium sulfate, AFt is produced, after that, AFm is produced (converted from AFt).

The Influence of Alcohol Amine Admixtures on the Macroscopic Properties of Portland Cement Paste

It is studied the influence of triethanolamine (TEA), diethylenetriamine (DEA), Triisopropanolamine (TIPA), aminoethyl ethanolamine (AE), and polyvinyl alcohol ammonium phosphate (PAAP) at different dosages on the properties of fresh and hardened cement pastes and mortars prepared by Portland cement, including standard consistency water, setting time, the cement paste fluidity, and compressive and flexural strength. It is showed that the high polarity alcohol amine molecules exhibit strong chemical interactions with cement matrix, which are reflected in modified macroscopic properties of the cement system. All alcohol amine admixtures increased the standard consistency water and decreased cement paste fluidity of Portland cement. TEA significantly shortened the initial setting time and final setting time of Portland cement. On the other hand, TIPA, DEA, AE and PAAP extended the initial setting time of cement but shortened the cement final setting time. All alcohol amine admixtures except TIPA at 0.2 and 0.5 dosage increased the compressive and flexural strength of the Portland cement mortars at 3 days. Especially when the dosage of PAAP is 1, the compressive strength of the Portland cement mortars at 3 days is increased 10.5MPa. All alcohol amine admixtures except AE at 0.2 and 0.5 dosage increase the compressive and flexural strength of the Portland cement mortars at 28 days, Especially when the dosage of TIPA is 1, the compressive strength of the Portland cement mortars at 28 days is increased 8.8MPa.

Influence of triethanolamine on the hydration and the strength development of cementitious systems

The influence of triethanolamine (TEA) at varying dosages on the strength development of pure cement (PC) and fly ash cement (FAC) pastes was systematically investigated. Techniques including mercury intrusion porosimetry, X-ray diffraction, thermogravimetric analysis and scanning electron microscopy were employed to characterise the microstructure of hardened cement pastes and to monitor the cement hydration process with the aim of correlating strength variations with microstructural changes caused by TEA addition. The results showed that 0·03–0·10% addition of TEA visibly enhances the early strength but decreases the compressive strength after 3 d for PC pastes. A high dosage of TEA (1%) leads to a sharp decrease in 28-d strength for both PC and FAC pastes. Mechanistic explanations regarding why TEA affects the strength development differently at different dosages and ages are discussed by considering the impacts of TEA on the hydration degree, pore structure, composition and morphology of hydration products.

Influence of Triethanolamine on Aqueous β-Cyclodextrin/Pyrene Complexes

The influence of triethanolamine (TEA) on the aqueous β-CD/pyrene fluorescence is examined. Collisional quenching of pyrene by TEA is indicated by Stern-Volmer plots. However, a decrease in the quenching is observed in the presence of β-cyclodextrin, which indicates an effective protection of the included pyrene molecules against quenching from TEA. A decrease in the apparent formation constant of the β-CD/pyrene complex also occurs in the presence of TEA. This phenomenon is attributed to a combination of an increased bulk solvent hydrophobicity and a competitive equilibrium between pyrene and TEA for the β-CD cavity. The present study indicates that TEA is not co-included in the β-CD/pyrene complex.

Effects of amines on the formation of β-ferric oxide hydroxide

Colloidal particles of β-ferric oxide hydroxide (β-FeOOH) were prepared by ageing an FeCl3 solution at 100°C in the presence of various amines with different numbers of nitrogen atoms. The particle and crystallite sizes of the formed β-FeOOH decreased with increasing concentration of amines, but the particles produced contained no amine. The influence of triethanolamine on the growth of β-FeOOH particles was more marked than those of ethylenediamine, diethylenetriamine and triaminotriethylamine. The adsorption isotherms of nitrogen and water on the formed particles of different size were measured and surface fractal analysis was performed.

The Effect of Triethanolamine on the Iron(III)-Catalysed Decomposition of Hydrogen Peroxide

Abstract The influence of triethanolamine on the iron(III)-catalyscd decomposition of hydrogen peroxide was studied by manometric and spectrophotometric techniques. This ligand caused increasing inhibition with increasing concentration, attributed to the saturation of the coordination sphere of the metal, and also to its properties as a radical scavenger. Kinetic measurements indicated the formation and the subsequent breakdown of a peroxo-intermediate in the rate-determining step, for which a rate constant of 2.9 × 10−2 s−1 was determined at 308 K. Evidence for the participation of oxygen radicals, as well as carbon-centred radicals, was obtained from ESR spectra of the radical adducts detected using the spin-trap method. Based on the pH profile for the reaction, a mechanism was proposed, suggesting the formation of different complexes with different catalytic activities, at higher pH.

Influence of triethanolamine on the hydration characteristics of tricalcium silicate

AbstractThe hydration characteristics of 3CaO.SiO2 or β2CaO.SiO2 are studied by an addition of 0.0, 0.1, 0.5 or 1.0% triethanolamine. The amount of Ca(OH)2 found at 1, 3, 7 or 28 days was in the order C3S + 0% TEA &gt; C3S +0.1% TEA &gt; C3S + 0.5% TEA &gt; C3S+1.0% TEA, irrespective of whether lime was estimated by X‐ray, DTA, TGA or chemical analysis. The rate of hydration, in terms of the disappearance of 3CaO.SiO2, showed that hydration proceeded faster in the presence of TEA after 1 day. Additions of TEA increase the induction period, promote the formation of a C‐S‐H with higher CaO/SiO2 ratio, increase the formation of non‐crystalline Ca(OH)2 and enhance the surface area of the hydrated silicate product.

Effects of Triethanolamine on Hemolysis.

The author's previous work on the surface tension lowering substance, sodium taurocholate, and its effects on red blood cells as demonstrated by hemolysis suggested like observations on triethanolamine, N (C2H4OH)3, a new surface tension lowering compound now used commercially as an emulsifying agent and superior to similar agents previously used because of its low alkalinity, ability to cause finer and more stable dispersions, its slightly bactericidal powers, etc. Approximately 25 human bloods were examined, a drop of blood drawn from the patient by syringe being added directly to each tube containing 2 cc. of the solution to be observed. Varying dilutions of sodium chloride, potassium chloride, calcium chloride, sodium hydroxide, hydrochloric acid, acetone, saponin, sodium taurocholate, venom from the bothrops atrox and sulphanilic acid were observed for hemolysis as such and containing 5% triethanolamine and the results compared. The influence of triethanolamine on the pH of the solutions and the time of hemolysis were also noted. The first readings registered were taken 2 hours after the addition of the blood. Normal sodium chloride was used as a vehicle with the exception of the sodium, potassium and calcium chloride dilutions and where otherwise noted. The pH of the distilled water and normal sodium chloride ranged from 5.6-5.8. In the case of the sodium chloride dilutions, hemolysis began at the .40% concentration of the salt without triethanolamine and at the .30% concentration with the triethanolamine, the triethanolamine in each case definitely increasing the alkalinity of the solutions. Similar results were obtained with the potassium and calcium chlorides.