Amine Solutions Research Articles

Binary Solvent System for Extraction of Cathode Material From Spent Li-ion Batteries

An effective method of water and carbon tetrachloride (CCl4) system has been studied to recover metals ions from spent Li-ion battery cathode materials. Leaching of HCl and HCl + H2O2 has been applied individually to dissolve the collected cathode materials. Metal ions dissolved in HCl and HCl + H2O2 has been treated separately with a solution of hexadecyl amine in CCl4. The formation of metal ions-hexadecyl amine complex has been confirmed from UV-visible spectroscopy. Recovery of metals from the produced complex has been carried out via filtration and calcination. The calcined materials has been characterized using Fourier transform infrared spectroscopy (FT-IR),field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) andpowder x-ray diffraction (XRD). Dhaka Univ. J. Sci. 69(3): 225-229, 2022 (June)

From biopolymer dissolution to CO2 capture under atmospheric pressure - A molecular view on biopolymer@Ionic liquid materials

Finding a cheap and easily recycling material that can capture CO2 under atmospheric pressure (1 atm) is of paramount importance. In this context, combining ionic liquids (ILs) with abundant and natural materials, such as chitin-based biopolymers, appears as an interesting alternative. In this work, four acetate-based ILs were selected to explore the solubility of chitin, chitosan, and carboxymethyl-chitosan. Using carboxymethyl-chitosan and biopolymer monomer units as models, different Nuclear Magnetic Resonance (NMR) techniques, namely, 1H, 13C, nuclear Overhauser effect spectroscopy, and spin-lattice relaxation, were performed to evaluate the dissolution. Shrimp shells were used as a chitin source. Through a simple acid/base treatment, it was possible to remove minerals and proteins, and use it to prepare biopolymer@IL materials for CO2 capture tests. Efficient CO2 sorption capacity was observed upon bubbling CO2 with a maximum of 2.32 mmolCO2/gsorbent. Under N2 bubbling, the system demonstrated excellent recycling capacity using a room temperature procedure that outperformed aqueous amine solutions recycling. The absence of heating and vacuum recycling procedures, combined with the use of N2 or compressed air is much more appealing for industrial applications.

Insights into the interaction between typical amines and alkaline minerals for improved CO2 absorption and mineralization

AbstractAmine scrubbing is a mature technology to cut down CO2 emissions from human activities but suffers from a high energy consumption of solvent regeneration. The integrated CO2 absorption and mineralization (IAM) process can effectively reduce the energy consumption of amine regeneration by replacing traditional thermal regeneration with chemical regeneration via CO2 mineralization. However, a fundamental understanding of the interaction between typical amines and alkaline minerals was still lacking. In this paper, the effects of amine types on amine regeneration, alkaline metal leaching, and CaCO3 precipitation during the IAM process were explored by using five typical amines and Ca(OH)2/Mg(OH)2. Results showed very different regeneration kinetics and efficiencies were observed in five selected amine solutions, which displayed a decreased performance in the order TEA > MDEA > DEA > AMP > MEA. The regeneration performance was significantly affected by the dissolution of Ca(OH)2/Mg(OH)2 which was inversely proportional to the trend of their pKa values. TEA displayed the largest regeneration efficiency of about 95% by Ca(OH)2 and 83% by Mg(OH)2, which was much larger than other amines reported in the open literature, due to its lower pKa value than other selected amines. More interestingly, the particle size of CaCO3 produced from amine solutions was smaller than that from CaCl2 solution reported in the literature. There was a rough linear relationship between CaCO3 particle size and amine pKa values. TEA induced the formation of nano scaled CaCO3, which might be attributed to the adsorbing of TEA on the CaCO3 crystal and inhibiting the crystal growth. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.

Experimental Measurement and Modeling Prediction of Mass Transfer in a Hollow Fiber Membrane Contactor Using Tertiary Amine Solutions for CO2 Absorption

Experimental Measurement and Modeling Prediction of Mass Transfer in a Hollow Fiber Membrane Contactor Using Tertiary Amine Solutions for CO₂ Absorption

Experimental study and modified modeling on effect of SO2 on CO2 absorption using amine solution

Understanding the competitive mechanism in absorption process between SO2 and CO2 is essential for simultaneous absorption of SO2 and CO2. In this study, the effect of SO2 on CO2 absorption using amine solution was studied experimentally and theoretically. The CO2 absorption rates in MEA/MMEA/MDEA solutions were determined using wetted wall column. Results showed that the reduction of flue gas temperature was beneficial for CO2 absorption at the typical coal-fired flue gas CO2 concentration. On this basis, the effect of SO2 on CO2 absorption performance was studied. Firstly, the overall CO2 mass transfer coefficient decreased under exposure to SO2. Secondly, in the presence of SO2, pH variation of amine solution increased. In addition, the saturated CO2 capacity largely decreased when SO2 was continuously bubbled into the solution. Furthermore, the quantum chemical calculation showed that CO2 had little effect on the absorption performance of SO2 whereas SO2 greatly weakened the interaction between CO2 and amines. The overall CO2 mass transfer coefficient was modified considering the effect of SO2. The competitive absorption factor, χ, was introduced to modify the CO2 liquid phase diffusion coefficients. The average deviation of overall CO2 mass transfer coefficient narrowed to 1.76 % (0.5 mol/L MEA), 1.13 % (1.0 mol/L MEA), 1.88 % (1.0 mol/L MMEA) and 1.43 % (1.0 mol/L MDEA) respectively, which agreed well with the experimental results.

Effects of hydroxyethyl group on monoethanolamine (MEA) derivatives for biomethane from biogas upgrading

Upgrading of biogas to produce biomethane is an essential way to increase the calorific value of biogas by separating CH4 and CO2 to satisfy the global renewable energy demand. In this study, the efficiency of carbon dioxide (CO2) trapping in aqueous monoethanolamine (MEA), diglycolamine (DGA), diethanolamine (DEA), and triethanolamine (TEA) solution during biogas upgrading for biomethane was determined. Effects of hydroxyethyl groups on MEA derivatives were investigated in terms of biogas upgrading and regeneration, CO2 desorption heat, initial CO2 absorption rate and CO2/CH4 selectivity. The duration of upgraded biogas meeting certain European Union (EU) application standards for methane purity during upgrading was reduced by 70, 78 and 200 mins for DGA, DEA and TEA respectively compared to MEA due to the partial substitution of H-bonds by hydroxyethyl groups, and the absorption rate was also reduced, whereas TEA was not suitable for biogas upgrading as it was inefficient for biogas upgrading effect and absorption rate. The calculated results from the Gibbs-Helmholtz equation showed that MEA had the largest CO2 desorption heat (82.47 kJ/mol CO2) and the other MEA derivatives had lower desorption heat than MEA, indicating that MEA consumes more energy in the desorption process. As for the equilibrium partial pressure, all amine solutions absorbed less than 0.4% of the total volume of CH4 and had a high CO2/CH4 selectivity.

Development of biphasic solvent for CO2 capture by tailoring the polarity of amine solution

A facile screening method for amine/phase splitter/H2O biphasic solvents was proposed. The polarity difference between the high polarity absorption products and the low polarity phase splitter was recognized as the decisive factor for phase separation. In this study, biphasic solvent was developed by tailoring the polarity of absorption products. It’s revealed that the amine/1-propanol/H2O solvents with a dipole moment difference above 6.0 Debye featured phase separation. After screening, TETA/1-propanol/H2O biphasic absorbent with high CO2-rich loading and low regeneration energy was developed. The phase separation behavior was affected by TETA concentration, 1-propanol concentration, and the absorption temperature. Remarkably, the CO2 capacity and volume distribution of the rich phase can be simply tuned by altering the 1-propanol concentration. For the optimal composition of 30 wt% TETA and 50 wt% 1-propanol, a rapid phase separation in 2 min was observed at 60 °C. And the rich phase exhibited a CO2 capacity as high as 6.06 mol/L with a volume proportion of 38.9%. With the promotion of 1-propanol, the CO2 mass transfer coefficient in TETA/1-propanol reached 21.4 × 10−11 mol/cm2·s·Pa, 42.7% higher than 30 wt% TETA and 110.2% higher than 30 wt% MEA. The estimated regeneration heat was 2.06 GJ/t CO2, 48.4% lower than 30 wt% MEA. This research provided a facile screening method and a promising alternative absorbent for CO2 capture.

New methylene blue analogues with N-piperidinyl-carbinol units: Synthesis, optical properties and in vitro internalization in human ovarian cancer cells

In this work, two new phenothiazinium dyes containing N-piperidinyl-carbinol auxochrome units have been designed, synthesized and investigated in vitro for ovarian cancer cell fluorescence imaging and cytotoxicity. A solvent free mechanochemical procedure is described as a greener alternative to the previously reported synthetic methodology applied in the preparation of methylene blue analogues by the substitution of the phenothiazinium tetraiodide substrate with nucleophilic secondary amines in solution. The optical properties of the new dyes were evaluated by UV–vis absorption/emission spectroscopy which revealed maxima situated in the red region (λmaxabsorption = 668-664 nm and λmaxemission = 715-698 nm) with large molar extinction coefficients (log ε = 4.5–5.1) and bathochromic shifts of 314–383 cm−1 occurring upon switching from less polar to more polar solvents. The theoretical DFT computational study performed in order to clarify the obtained data indicated that the vertical TD-DFT calculations (typically applied for simulating UV–vis spectra) were within ∼150 nm of the experimental data, but a better agreement with experiment was obtained by using the vibronic corrections which revealed a dominant vibronic component not only for the main absorption/emission maxima, but also for the displayed shoulders which are rather the effects of the vibronic coupling between S0 and S1 electronic states. The new dyes presented a hydrophilic character (logPn-octanol/water = −1.15 and −1.29 respectively) comparable to the parent methylene blue and no aggregation tendency was observed in aqueous solution at concentration range 75–150 μM used in this study. Cellular imaging experiments displayed the new dyes' ability to selectively stain the cytoplasm of tumoral OVCAR-3 and A2780 fixed cells. The evaluation of their biological activity encompassed cell grow inhibitory potential (dose-response activity and half maximal inhibitory concentration IC50), as well as their capacity to influence the tumoral OVCAR-3, A2780 and healthy BJ ovarian cells’ metabolic activity. Dye 2 exhibited moderate cytotoxicity against human ovarian cancer cell lines, being the most active against the A2780 ovarian adenocarcinoma cells where its cellular uptake was noteworthy and displayed a deeper influence on the chemoresistant, highly malignant OVCAR-3 cells function by modulating FOLR1, ICAM-1 and VCAM-1 proteins with role in the growth and migration of cancer cells.

Capillary Microreactor for Initial Screening of Three Amine-Based Solvents for CO2 Absorption, Desorption, and Foaming

Microreactor is a very attractive laboratory device for screening conditions and solvents in an efficient, safe and fast manner. Most reported work on microreactors for CO2 capturing deals with absorption and mass transfer performance with a limited number of studies on solvent regeneration. For the first time, foaming, which is a major operational challenge of CO2 capturing is being studied in combination with absorption and desorption in a capillary microreactor setup. To demonstrate the setup capabilities, three known amine-based solvents (MEA, MDEA, and AMP) were selected for the screening and evaluation studies. MEA had the highest CO2 absorption efficiency while MDEA had the lowest one. CO2 absorption efficiency increased with temperature, liquid flow rate, and amine concentration as per the literature. During the absorption work, the Taylor flow regime was maintained at the reactor inlet. CO2 desorption of loaded amine solutions was investigated at different concentrations and temperatures up to 85°C. MDEA solution had the highest desorption efficiency, followed by AMP and the least desorption efficiency was that of MEA. Foaming experimental results showed that MEA had a larger foaming region compared to AMP. However, more foaming happened with AMP at higher gas and liquid flow rates. A plug flow mathematical reactor model was developed to simulate the MEA-CO2 system. The model captured well the performance and trends of the studied system, however the absolute prediction deviated due to uncertainties in the used physical properties and mass transfer correlation. Selecting a solvent for chemical absorption depends on many more factors than these three studied parameters. Still, microreactor proves a valuable tool to generate experimental results under different conditions, with the least amount of consumables (less than 1 L solvents were used), in a fast manner, combined with a knowledge insight because of the uniqueness of the Taylor flow regime.

Thermophysical Properties of Alkanone + Aromatic Amine Mixtures at Varying Temperatures.

In the present investigation, an attempt has been made to evaluate internal pressure , energy , and enthalpy of vaporization along with excess entropy and excess isothermal compressibility for binary solutions of alkanones (2-propanone, 2-butanone, and 2-heptanone) and aromatic amines (aniline, N-methylaniline, and pyridine) at 293.15, 298.15, and 303.15 K, respectively. The cohesive energy density (CED) and solubility parameter are studied to understand the strength of molecular interactions. The coefficient of thermal expansion and isothermal compressibility have also been investigated using empirical equations and have been employed to understand the molecular interactions. All the evaluated properties have been used to understand the nature and extent of intermolecular interactions taking place. The observed trends in the properties and their variations have been discussed in terms of varying chain lengths of the alkyl group and the hydrogen bonding capability of the components. The findings show that the extent of interactions follows an order: aniline > NMA > pyridine, keeping the alkanone constant at all the temperatures under study.

Effects of Alkyl Groups on Monoethanolamine Derivatives for Biomethane from Biogas Upgrading

Amine scrubbing is one of the key technologies for biogas upgrading to biomethane, which can be used to increase the calorific value of biomethane by separating out CO2 to meet the global demand for renewable energy. In this paper, several monoethanolamine (MEA) derivatives with alkyl groups as variables are screened as sorbents for the biogas upgrading process. The effect of alkyl groups on the efficiency of biogas upgrading, the effectiveness of sorbent regeneration, and the selectivity of CO2/CH4 during biogas upgrading are investigated. The analysis of biogas upgrading experiments with different MEA derivatives shows that methyl and butyl are more favorable for improving CO2 absorption and meeting the biogas upgrading effect of methane purity for a long period of time applicable in some countries, and ethyl is more conducive to the regeneration efficiency of amines. The results of the CO2 desorption heat calculations show that the CO2 desorption heat of ethyl monoethanolamine (EMEA) (66.67 kJ/mol CO2), formed by replacing a hydrogen near the nitrogen with an ethyl group, is significantly lower than those of methyl monoethanolamine (MMEA) (73.04 kJ/mol CO2) and butyl monoethanolamine (BMEA) (73.27 kJ/mol CO2), formed by replacing a hydrogen near the nitrogen with a methyl group and a butyl group, respectively. The CO2 desorption heats were significantly lower than those of MEA (82.12 kJ/mol CO2), suggesting that ethyl can significantly reduce the CO2 desorption heat of the amine compared to other alkyl groups. In the CO2/CH4 selectivity experiments, BMEA showed the fastest initial CO2 absorption rate of 0.83%/s, while dimethyl monoethanolamine (DMMEA) showed the lowest initial CO2 absorption rate of 0.16%/s. All amine solutions showed less than 1% absorption of CH4 and had high CO2/CH4 selectivity.

Kinetics of CO2 absorption into ethanolamine + water + ethanol system—mechanism, role of water, and kinetic model

The kinetics of CO2 absorption in ethanolamine (MEA) + H2O + ethanol systems was investigated using stopped-flow apparatus. The first-order reaction rate constant (k0) values were tested with varying H2O and MEA concentrations. Transiting from the aqueous to non-aqueous solvents, the k0 decreases and the reaction order for MEA shifts from 1.05 to 1.88. The zwitterion mechanism with the rate-limiting step of deprotonation was used to explore the role of water and its effect. Results showed that water could impact reactions through direct involvement and changing solvation environment. An improved kinetic model based on the zwitterion mechanism was obtained to indicate the quantitative influence of H2O concentration on the reaction kinetics of MEA + H2O + ethanol systems. The predicted values from the model well agreed to the experimental data with the average absolute relative difference of 6.73%. This study highlights the important effects of water on the reaction kinetics of CO2 absorption into water-lean amine solutions.

Biogas upgrading with various single and blended amines solutions: Capacities and kinetics

Biogas is an important renewable energy and biogas upgrading which separate CH4/CO2 to increase the heating value of biogas is necessary for its utilization. Amine scrubbing is a promising biogas upgrading technology. In this study, we applied various single and blended amines solutions for biogas upgrading and reconsidered the evaluation method by comparing the equilibrium CO2 absorption capacity (qe) and optimal CO2 absorption capacity under 90 vol% or 95 vol% pure CH4 requirement (q90%CH4, q95%CH4). Three apparent kinetic models and Fourier-transform infrared spectroscopy (FT-IR) were applied to study the kinetics. The results showed that, compared with the qe, the new indicator q90%CH4 and q95%CH4 could better reveal the difference and improvements between various amines solutions and be more accordance with the real situation of biogas upgrading. The q90%CH4 increased from 0.15 to 0.82–1.70 mol/kg after adding other amines with methyldiethanolamine (MDEA), but qe was almost the same. For kinetics, the fitting results of Avrami model are the best among the three models. FT-IR analysis before and after absorption showed CO2 formed different groups with different amine molecules. This study provided a new perspective and method on evaluation of amine scrubbing for biogas upgrading, contributing to future research and industrial application.

Strong Photocurrent Response of Selenoarsenates With Different Transition Metal Complexes as Structure-Directing Agents.

Four selenoarsenates with different transition-metal complexes [Co(tren)2H]AsSe4 [tren = tris(2-aminoethyl)amine] (1); [Ni2(dien)4](As2Se5) (dien = diethylenetriamine) (2); [Zn(tren)]2(As2Se5) (3) and [Mn(tren)]2(As2Se5) (4) were solvothermally synthesized in a mixed solvent of organic amine and alcohol solution. The compounds 1-4 have pyramidal/tetrahedral structures (AsSe3/AsSe4), and contain transition metal (Co2+, Ni2+, Zn2+ and Mn2+) complex that form distinct zero-dimensional (0-D) clusters. Arsenic atoms form a tetrahedron in compounds 1 and 2; 1 consists of discrete tetrahedral (AsSe4) and transition metal complex [Co(tren)2]2+; 2 is composed of an anion [As2Se5]4- cluster and transition metal complex [Ni(dien)2]2+. In compounds 3 and 4, arsenic atom forms a pyramidal AsSe3 and the two pyramidal AsSe3 share a corner connection to form a dimer [As2Se5]4-; 3 is characterized as a cluster consisting of two unsaturated [Zn(tren)]2+ caiton linked by a dimer (As2Se5)4- linkage; in 4, unsaturated [Mn(tren)]2+ caiton is linked to two trigonal-bipyramidal [Mn(tren)]Se via dimer (As2Se5)4- to form [Mn(tren)]4[As4Se10] cluster. To our knowledge, [Zn(tren)]2(As2Se5) (3) is the first zinc selenoarsenate containing the (As2Se5)4- anion type. Furthermore, the Mn2+ ions adopt a trigonal-biyramidal (five-coordinate) and octahedral (six-coordinate) environment. Adding K2CO3/Cs2CO3 to the synthesis system is necessary and may act as a mineralizer. Several properties of compounds 1-4 have been characterized in our studies, in particular their strong photocurrent response characteristics under visible light irradiation.

Electrochemical Dehydrogenation Pathways of Amines to Nitriles on NiOOH.

Nitriles are highly important synthetic intermediates with applications in a wide variety of organic reactions including production of pharmaceuticals, fine chemicals, and agricultural chemicals. Thus, developing effective green routes to oxidize amines to nitriles is of great interest. One promising method to achieve the oxidation of primary amines to nitriles is through electrochemical oxidation on NiOOH electrodes. This reaction has long been thought to occur through an indirect mechanism consisting of a series of potential independent hydrogen atom transfer steps to catalytic Ni3+ sites in NiOOH, which reduces NiOOH to Ni(OH)2. The role of the applied potential in this mechanism is simply to regenerate NiOOH by oxidizing Ni(OH)2. In this work, we demonstrate that a second, potential-dependent pathway recently found to apply to alcohol and aldehyde oxidation on NiOOH and consisting of potential-dependent hydride transfer to Ni4+ sites is the dominant pathway for the oxidation of amines using propylamine and benzylamine as model systems. After qualitatively and quantitatively examining the contributions of indirect and potential-dependent oxidation pathways to amine oxidation on NiOOH, we also examine the effect the amine concentration, solution pH, applied bias, and deuterium substitution have on the two pathways, further clarifying their mechanisms and exploring what factors control their rate. This work provides a comprehensive understanding of the mechanism of primary amine oxidation on NiOOH.

Fibrous Polyethyleneimine‐Functionalized Cellulose Materials for CO2 Capture and Release

AbstractPoly(ethyleneimine) (PEI) immobilized on support materials are valuable alternatives to aqueous amine solutions for carbon dioxide (CO2) capture from the atmosphere since the thermal desorption of CO2 from these materials usually requires less energy. Herein, fibrous PEI‐functionalized carrier systems based on cellulose, cellulose tosylate (CT), and cellulose carbamate (CC) are described. Branched PEI is used for functionalization since higher CO2 sorption capacities compared to linear PEIs can be achieved. Under wet conditions, a PEI‐functionalized nonwoven material has a sorption capacity of 0.026 mg CO2/mg adsorbent; complete and reversible CO2 desorption is accomplished at 80 °C.

Numerical Investigation on a Liquid–Gas Ejector for Carbon Dioxide Removal Using Amine Solution: Hydrodynamics and Mass Transfer Evaluation

The present study investigates the hydrodynamics and mass transfer of the liquid–gas ejector using three-dimensional (air–water) and two-dimensional (CO2/air-MEA (Monoethanolamine) solution) computational fluid dynamics (CFD) modeling. For 3D simulation, validation of the CFD results of this ejector with experimental data (error less than 5%) showed high simulation accuracy. The effects of motive liquid flow rate and outlet pressure parameters on the air entrainment rate and air hold-up are also investigated. It was found that by increasing the outlet pressure by about 70% (from 3587 to 6127 Pag), the rate of gas entrainment and gas hold up decreased by about 37% and 20%, respectively. On the contrary, these parameters showed increasing behavior of about 74% and 15%, respectively, when the mass flow rate of liquid increased by about 21%. In addition, three-dimensional phenomena such as mixing shock and the location of its occurrence are examined, which is the reason for recirculation and vortex in the ejector. Next, by simulating a two-dimensional simulation and changing the inlet fluids to CO2/air-methanol amine, the ejector was designed to simultaneously increase the gas pressure and absorb carbon dioxide. A user-defined function code was used to express the mass transfer from the gas to the liquid phase. The results, in this case, showed that with increasing the outlet pressure of the ejector (from 0 to 2000 Pag), and enhancing the concentration of MEA solution (from 10% to 30%), the CO2 removal boosted from 83% to 95%. A similar behavior was shown when the L/G ratio increased from 3.5 to 5.5. This study serves as a showcase on how to do an exact design and analysis for liquid–gas ejectors in flare gas recovery systems.

Heteropolyacid modified Cerium-based MOFs catalyst for amine solution regeneration in CO2 capture

The CO2 desorption process consuming excessive energy in traditional CCUS technology becomes a great challenge to achieve the goal of carbon neutrality. The multi-acid site on solid acid catalyst promote regeneration reaction proceeds. In order to solve the property defects of a single type of catalyst, we introduced heteropolyacids into cerium-based MOFs materials to increase acid sites. The composite catalyst named CeO2-MOF-HPW (CeM-HPW) shows good catalytic performance. The CO2 desorption capacity and rate were increased by 38.1% and 166%, respectively, and the desorption energy consumption was reduced by 29.4% in comparison with the uncatalytic process. CeO2 and HPW synergistically promote the decomposition of carbamate. Heteropolyacid anions help the deprotonation process for proton transfer. The catalytic approach reduces the energy barrier of the desorption reaction so as to obtain a desorption effect with high efficiency and low energy consumption. This catalyst provides a new idea for low energy consumption CCUS technology.

Pseudo-crown ether III: Naphthalimide-Pd(II) based fluorogenic ensemble for solution, vapour and intracellular detection of amine and anti-counterfeiting applications

A bis-naphthalimide based pseudo-crown ether as metal complex-based ensemble (DN-1 + Pd2+) is reported for the sensing of tris(2-aminoethylamine) (TAEA). The DN-1 moiety exhibited cyan blue fluorescence in solution and solid state (CIE plot) with high quantum yield (φ = 0.92). The DN-1 showed selective fluorescence quenching at 450 nm upon addition of Pd2+ ions, whereas ensemble showed revival of the fluorescence upon addition of TAEA owing to displacement of Pd2+ ions from the binding cavity due to higher binding affinity of TAEA for Pd2+ ions. The detection limit of DN-1 for Pd2+ is 0.1 µM and the ensemble for TAEA is 0.8 µM. The complexation–decomplexation mechanisms were supported by optical, NMR, DLS, CV and AFM studies. The DN-1 and ensemble were successfully utilized for the intracellular imaging of Pd2+ ions and TAEA, respectively, in MG-63 live cells. The ensemble was successfully utilized for fabrication of solution and SiNPs based test kits for the detection of TAEA in solution and vapour phase. The DN-1 was further employed as information security ink for the anti-counterfeiting applications and for fabrication of IMPLICATION logic gate.

Monoamine‐modified thin film composite nanofiltration membrane for permselective separation of fermentation bioproducts

AbstractOne process involved in biorefinery for generation of value‐added products is fermentation. After fermentation, the downstream bioproduct purification process is conventionally performed by organic solvent extraction, which is environmentally‐hazardous and costly. Membrane‐based separation is a cost‐efficient and environmentally‐benign method for bioproduct separation and purification. In this study, a thin film composite (TFC) nanofiltration (NF) membrane was prepared and the pore size and charge of the polyamide layer were controlled by introducing iminodiacetic acid (IDA), a charged monoamine monomer, with piperazine (PIP) during interfacial polymerization (IP). The newly‐developed NF membrane was found to have a molecular weight cut‐off (MWCO) of 500 to 1350 Da, allowing the permeation of the fermentation product, while rejecting other higher molecular weight compounds. IDA addition in the aqueous amine solution during IP effectively engineered the MWCO values and pore sizes of TFC NF membranes for specific applications, such as separation of fermentation bioproducts. This study successfully showed that IDA reduced the diffusivity of PIP during IP, which negatively affected the polyamide formation and membrane performance. The optimal PIP:IDA concentration ratio was determined by MWCO and effective pore diameter for effective bioproduct separation and purification, which could not be performed by the current commercially‐available NF membranes.