Short-chain Amine Research Articles

Cost‐Effective and Scalable Enzyme‐Mediated Preparation of Short‐Chain Primary Amines

AbstractAmines, crucial components in various industries, play a pivotal role in the synthesis of pharmaceuticals, agrochemicals, and specialty chemicals. Recognizing the environmental impact of conventional methods for their preparation, our study centers on the utilization of abundantly available natural molecules, specifically amino acids, as precursors for short chain amine synthesis. This paper focuses on the biocatalyst, L‐valine decarboxylase from Streptomyces viridifaciens (VlmD), delving into the substrate scope, catalytic activity, and cost‐effective scalability of an enzymatic process for amine synthesis. Additionally, we investigate the feasibility of immobilizing VlmD, aiming to pave the way for its effective use in industrial applications. Our study exploits the SpinChem system and provides a comprehensive understanding of the potential and limitations of this biocatalyst. Notably, our yields for key amines (8.42 g ⋅ d−1 for isobutylamine, 5.23 g ⋅ d−1 for isoamylamine, 5.16 g ⋅ d−1 for (S)‐2‐methylbutylamine, 3.78 g ⋅ d−1 for 3‐(methylthio)propylamine, and 10.52 g ⋅ d−1 for (R)‐1‐amino‐2‐propanol) demonstrate the process efficiency and potential for industrial scalability.

Bacterial Metabolites and Inflammatory Skin Diseases.

The microbiome and gut-skin axis are popular areas of interest in recent years concerning inflammatory skin diseases. While many bacterial species have been associated with commensalism of both the skin and gastrointestinal tract in certain disease states, less is known about specific bacterial metabolites that regulate host pathways and contribute to inflammation. Some of these metabolites include short chain fatty acids, amine, and tryptophan derivatives, and more that when dysregulated, have deleterious effects on cutaneous disease burden. This review aims to summarize the knowledge of wealth surrounding bacterial metabolites of the skin and gut and their role in immune homeostasis in inflammatory skin diseases such as atopic dermatitis, psoriasis, and hidradenitis suppurativa.

Efficient coal concentration using a short-chain amine-type compound as collector reagent: Flotation and optimization studies

This work presents the flotation of a sub-bituminous coal using 1-butylamine as a short-chain amine collector. The flotation results have been obtained with 1-butylamine (coal yield: 100%) and compared with those achieved with a quaternary amine (coal yield: 95.4%), kerosene (coal yield: 100%) and diesel (coal yield: 95.7%). The best results have been obtained with 1-butylamine. Less depressant effect has been observed with 1-butylamine. The FTIR signals have been attenuated when the coal is conditioned with 1-butylamine. Zeta potential measurements have also been changed after conditioning. The contact angle of water and graphite has decreased from 82.3° to 32.2°. An optimization has been performed using a Box-Behnken experimental design. Flotation has significantly affected by time and collector dosage. The pH is not a significant factor. The optimal conditions for the best efficiency using 1-butylamine as a collector are 2.0 min of flotation and 10-3 mol/L of collector.

Intercalation of α-titanium phosphate with long-chain amine aided by short-chain amine

In the textile industry, various chemicals are used to produce quality yarns. Thinking about its future use for improving the dyeability of the textile yarns, the intercalation of alpha-titanium phosphate (α-TiP) using long-chain amine was accomplished. In this work, we studied α-titanium phosphate intercalation by a long-chain amine aided by a short-chain one. The synthesis of the titanium phosphate was performed using titanium isopropoxide and orthophosphoric acid with a molar ratio of 1:8. The phosphate was organically modified using two different amines—ethylamine (E) and the oligoetheramine [O-(2aminopropyl)-O’-(2-methoxyethyl) polypropylene glycol, Jeffamine®, (J)] using the 0.5:1 amine:phosphate molar ratio. The materials were characterized by thermogravimetry, Fourier-transform infrared spectroscopy, wide-angle X-ray diffractometry, Raman spectroscopy and energy-dispersive X-ray spectroscopy. JETiP and EJTiP thermogravimetric curves evidenced higher amine incorporation into titanium phosphate. X-ray diffractogram patterns of ETiP, JETiP and EJTiP showed new diffraction peaks coexisting with pristine one. Fourier-transform infrared spectroscopy indicated that amine was incorporated into α-TiP galleries as amine salt. Evaluation of several absorption ratios showed that better efficiency of amine intercalation was found in the JETiP and EJTiP assembled system. ETiP, JETiP and EJTiP Raman spectroscopy revealed change in α-TiP spectra owing to the chemical modification and intercalation promoted by amines. According to the energy-dispersive X-ray spectroscopy, JETiP and EJTiP showed the highest level of Jeffamine® incorporation. We concluded that the use of ethylamine was indispensable in the intercalation of long-chain amine inside the α-TiP galleries.

Nitrogen-Doped Alkylamine-Intercalated Layered Titanates for Photocatalytic Dye Degradation.

A layered titanate, K2Ti4O9, is intercalated with various n-alkylamines through ion-exchange reaction in aqueous medium. On heating, the intercalated amine is partially deintercalated, yielding nitrogen-doped amine-intercalated titanates. The modified titanates are studied as catalysts in methylene blue degradation under UV irradiation. Heat-treated long-chain amine titanates exhibit better photocatalytic activity in comparison to short chain amine titanates. The improved catalytic activity could be attributed to two factors: (i) increased surface access as the titanate layers are well separated, pillared by the alkylamine chains and (ii) nitrogen doping.

Oxidized coal flotation enhanced by adding n-octylamine

ABSTRACTOxidized coal is difficult-to-float using conventional diesel as the collector due to the abundant oxygen-containing groups on coal surface. In this study, a short-chain cationic amine, n-octylamine, was added into diesel in 1:4 ratio for enhancing oxidized coal flotation. X-ray photoelectron spectroscopy (XPS) was used to identify the interaction mechanism between diesel-n-octylamine mixture (DO) and oxidized coal. The results showed that the flotation yield using 500 g/t DO mixture was much higher than that of using 2000 g/t diesel under a similar ash content of clean coal. The addition of n-octylamine was proven to be an effective way to lower the oily collector consumption in oxidized coal flotation. XPS showed that electrostatic bonding between n-octylamine and negative-charged hydrophilic sites on oxidized coal surface was responsible for the enhancement of flotation recovery using DO as the collector.

Hyperbranched poly(ether amine) (hPEA) as novel backbone for amphiphilic one-component type-II polymeric photoinitiators

To make photoinitiators (PI) to be polymeric and water-soluble is an effective approach to develop the high efficient photoinitiator systems with low-migration, low-toxic and environment-friend. We developed a series of novel amphiphilic hyperbranched polymeric photoinitiators (hPEA-TXs, and hPEA-BPs) by introducing thioxanthone (TX) or benzophenone (BP) moieties into the periphery of the hyperbranched poly(ether amine) (hPEA) comprised of the hydrophilic poly(ethylene oxide) (PEO) short chain and coinitiator amine moieties in the backbone. Compared with their water-soluble low-molecular weight analogues, the resulting hyperbranched polymeric photoinitiators hPEA101-TX, hPEA211-TX, hPEA101-BP and hPEA211-BP could be dissolved very well not only in many organic systems including acrylate monomers, but also in water with high solubility of 10wt%. The photopolymerization kinetics of water-soluble monomer acrylamide (AM) and three hydrophobic multifunctional acrylate monomers initiated by these hyperbranched photoinitiators were investigated in detail by photo-differential scanning calorimetric (photo-DSC). Both hPEA-TXs and hPEA-BPs can initiate photopolymerization of AM as efficiently as their low-molecular weight analogues MGA-TX and MGA-BP, respectively. The final double bond conversion (DBC) of oil-soluble monomer hexanediol diacrylate (HDDA) photoinitiated by these hyperbranched photoinitiators can reach as high as 99%. Especially for photopolymerization of multifunctional monomers initiated by these hyperbranched polymeric photoinitiators, the final DBC of trimethylolpropane triacrylate (TMPTA) and pentaerythritol tetraacrylate (PETTA) can reach 80% and 60%, respectively, which is much higher than that of low-molecular weight photoinitiators.

Flotation of copper-bearing carbonaceous shale in the presence of amine type frothers

<p>Hexylamine, chloro-derivative of propylamine, and ammonium chloride were used for flotation of Permian carbonaceous copper bearing shale from the Legnica-Glogow Copper Basin region in SW Poland. It was confirmed that naturally hydrophobic shale, known as Kupferschiefer, can be made floatable by application of short chain amines as frothers. It was also established that the short chain amine chloro-derivatives as well as salmiac, the first member of the amine family, can be used as a frother for flotation of the investigated shale sample. It results from the paper that the investigated amine frothers work similarly if the comparison of the flotation results is made using their concentration expressed in relative form taking into account the critical coalescence concentration of the frother.</p>

CO2 adsorption performance of different amine-based siliceous MCM-41 materials

A series of amine-based adsorbents were synthesized using siliceous MCM-41 individually impregnated with four different amines (ethylenediamine (EDA), diethylenetriamine (DETA), tetraethylenepentamine (TEPA) and pentaethylenehexamine (PEHA)) to study the effect of amine chain length and loading weight on their CO2 adsorption performances in detail. The adsorbents were characterized by FT-IR, elemental analysis, and thermo-gravimetric analysis to confirm their structure properties. Thermo-gravimetric analysis was also used to evaluate the CO2 adsorption performance of adsorbents. Longer chain amine-based materials can achieve higher amine loadings and show better thermal stability. The CO2 adsorption capacities at different temperatures indicate that the CO2 adsorption is thermodynamically controlled over EDA-MCM41 and DETA-MCM41, while the adsorption over TEPA-MCM41 and PEHA-MCM41 is under kinetic control at low temperature. The chain length of amines affects the CO2 adsorption performance and the adsorption mechanism significantly. The results also indicate that CO2 adsorption capacity can be enhanced despite of high operation temperatures, if appropriate amines (TEPA and PEHA) are applied. However, adsorbents with short chain amine exhibit higher adsorption and desorption rates due to the collaborative effect of rapid reaction mechanisms of primary amines and less diffusion resistance of shorter chain length amines.

Structure and Properties of Polybenzimidazole/Silica Nanocomposite Electrolyte Membrane: Influence of Organic/Inorganic Interface

Although increased number of reports in recent years on proton exchange membrane (PEM) developed from nanocomposites of polybenzimidazole (PBI) with inorganic fillers brought hope to end the saga of contradiction between proton conductivity and variety of stabilities, such as mechanical, thermal,chemical, etc.; it still remains a prime challenge to develop a highly conducting PEM with superior aforementioned stabilities. In fact the very limited understanding of the interactions especially interfacial interaction between PBI and inorganic filler leads to confusion over the choice of inorganic filler type and their surface functionalities. Taking clue from our earlier study based on poly(4,4'-diphenylether-5,5'-bibenzimidazole) (OPBI)/silica nanocomposites, where silica nanoparticles modified with short chain amine showed interfacial interaction-dependent properties, in this work we explored the possibility of enhanced interfacial interaction and control over the interface by optimizing the chemistry of the silica surface. We functionalized the surface of silica nanoparticles with a longer aliphatic chain having multiple amine groups (named as long chain amine modified silica and abbreviated as LAMS). FTIR and (13)C solid-state NMR provided proof of hydrogen bonding interactions between the amine groups of modifier and those of OPBI. LAMS nanoparticles yielded a more distinguished self-assembly extending all over the OPBI matrix with increasing concentrations. The crystalline nature of these self-assembled clusters was probed by wide-angle X-ray diffraction (WAXD) studies and the morphological features were captured by transmission electron microscope (TEM). We demonstrated the changes in storage modulus and glass transition temperature (Tg) of the membranes, the fundamental parameters that are more sensitive to interfacial structure using temperature dependent dynamic mechanical analysis (DMA). All the nanocomposite membranes displayed enhanced mechanical, thermal and chemical stability than neat OPBI. The lower water uptake and swelling ratio and volume in both acid and water reflected the more hydrophobic characteristic of the nanocomposites. All the nanocomposite membranes showed phosphoric acid (PA) values to be higher than OPBI but the levels showed decreasing trend with increasing silica content; the reason attributed to the interparticle interaction. The self-assembled clusters of LAMS nanoparticles in the matrix created more sites for proton hopping as a result of which the proton conductivity of all the nanocomposites displayed an increasing trend.

Facet-Controlled Metal Alloy Electrocatalysts for Oxygen Reduction Reaction: Unconventional Post Treatment of Pt3Ni Octahedral Catalysts for Enhanced Activity

The paper describes a ligand exchange approach to the post-synthesis treatment of solution phase produced Pt3Ni octahedral electrocatalysts for the reduction of oxygen. Ligand exchange using short-chain amine is shown to be critical for achieving high activity towards the oxygen reduction reaction (ORR). Unlike Pt or other ORR electrocatalysts without well-defined (111) surface, the maximum ORR activity for Pt3Ni octahedral catalysts was achieved at a low annealing temperature of 230℃. This study indicates a different thermal treatment strategy is required for Pt alloy electrocatalysts with well-defined (111) surface, such as octahedral, tetrahedral, and icosahedral nanoparticles.

Amphiphilic polymeric Michler's ketone (MK) photoinitiators (APMKs) containing PEO chain and coinitiator amine

AbstractA series of amphiphilic polymeric Michler's ketone (MK) photoinitiators (APMKs) were synthesized by incorporating PEO short chain, MK moiety, and coinitiator amine into the same polymeric chain. APMKs possess good amphiphilic ability and become water‐soluble when the molar ratio of MK(pipaz)2/PEO/piperazine is 2:3:1. UV–Vis measurement shows that APMKs possess the same characteristic absorption to MK derivatives. The photopolymerization of three monomers with different functionality and hydrophilicity, polyethylene glycol diacrylate (PEGDA), phenoxy ethyl acrylate (AMP‐10G), and 2,2‐bis[4‐(acryloxypolyethoxy)phenyl]propane (A‐BPE‐10) initiated by APMKs was investigated by photodifferential scanning (photo‐DSC). The results show that APMKs can photoinitiate the polymerization of hydrophilic and hydrophobic monomers efficiently. As for photopolymerization of water‐soluble PEGDA, the final conversion is higher than 94%. Therefore, APMKs will be expected to find potential in many fields. Copyright © 2009 John Wiley & Sons, Ltd.

Use of Short-Chain Amine in Processing of Weathered/Oxidized Oil Sands Ores

In this study, short-chain amines were tested for improving bitumen recovery from weathered/oxidized oil sands ores. Three different amines, n-propylamine, n-butylamine, and n-pentylamine, were used. The emphasis of this study was to improve air bubble−bitumen attachment, measured by an induction timer. Amine addition was found to significantly decrease the induction time of the air bubble attaching to bitumen, reaching a minimum value at pH 9. Among the tested amines, the shortest induction time was obtained with n-butylamine addition. Adsorption of n-butylamine on bitumen was confirmed by ζ-potential measurements. Finally, Denver cell bitumen flotation tests confirmed the results obtained from the induction time measurements. n-Butylamine is shown to be a good chemical aid to improve the extraction of bitumen from weathered/oxidized oil sands ores. Plant process water having 10 mM n-butylamine increased bitumen recovery by more than 20% for two weathered/oxidized oil sands ore samples.

Change in neuron aggregation and neurite fasciculation on EVAL membranes modified with different diamines

In this study, we modified poly(ethylene-co-vinyl alcohol) (EVAL) membranes by the covalent bonding of diamines via epoxidation of surface hydroxyl groups of EVAL to analyze the effect of immobilized diamines with different carbon chain length on the cultured cerebellar granule neurons. Morphological studies showed that neurons seeded on the diamine-immobilized EVAL membrane were able to survive and regenerate with formation of an extensive neuritic network. Furthermore, cultured neurons showed that the presence of diamine with different carbon chain length was able to effectively regulate the neuron adhesion, migration, aggregation, and neurite growth pattern, but mediated neuronal activity with equal efficacy. The short-chain amine stimulated neuron migration, aggregation, and neurite fasciculation, whereas the long carbon chain diamine maintained single neuron distribution with the defasciculated feature of the neurite. Although it is known that positively charged amine molecules can interact directly with cell surface proteoglycans to mediate cell attachment, this study further demonstrated that the terminal primary amine with different carbon chain length is involved in mediating cell-substrate interaction to further regulate neuron aggregation and neurite fasciculation. This indicates a delicate interaction of neuron with the immobilized diamine molecules on the EVAL membrane surface. This work is encouraging because the diamine- immobilized EVAL membranes can be applied for the establishment of different neural culture systems useful for future investigations of neuron biology under in vitro conditions.

Uranyl selenates with organic templates: Principles of structure and characteristics of self-organization

Basic structural principles of uranyl selenates with organic templates are outlined as follows. In compounds with short chain amine molecules (C:N < 8) the primary role plays the correspondence between topology of inorganic complex (isomerism) and structure and shape of a template. In the structures with long chain molecules (C:N ≤ 8), the molecules are associated to form 2- or 1-dimensional supramolecular templates that are connected with inorganic structure according to the charge density matching principle. Compounds with electro neutral molecules (crown ethers) have composite structure, where bonding between organic and inorganic parts is achieved through hydrogen bonding via intermediate oxonium clusters.

Allylamine-mediated DNA attachment to polycrystalline diamond surface

Allylamine, an unsaturated short carbon chain amine was used to mediate ss-DNA attachment to an H-terminated polycrystalline diamond thin film surface for biosensoric applications. At first, allylamine was photochemically tethered onto the diamond film surface; ss-DNA was then attached via the allylamine linkage. The DNA molecules are then hybridized with the complementary DNA molecules containing fluorescence labels followed by denaturing. Time-of-fight secondary ion mass spectrometry and fluorescence spectroscopy are used to confirm the allylamine bonding and the covalent DNA bonding to the diamond film surface, respectively.

Effect of Short-Chain Amine Coatings on the Performance of LiFePO[sub 4] Li-Ion Battery Cathodes

The effects of Short-Chain Amine Coatings on the Performance of LiFePO4 Li-Ion Battery Cathodes

Polymerization of linear aliphatic diamine-based benzoxazine resins under inert and oxidative environments

A series of linear aliphatic diamine-based benzoxazine monomers have been studied. Reaction times and purification procedures have been optimized for each individual diamine. The structure of these diamine-based benzoxazine monomers has been characterized by 1H and 13C NMR, and infrared spectroscopy. The rate of polymerization has been studied by Fourier transform infrared spectroscopy as a function of the chain length of the aliphatic amines. The glass transition temperatures (Tg) of the polybenzoxazines from these monomers are also studied. The short chain amine polybenzoxazine exhibits the Tg of around 170°C. The influence of the polymerization environment for these linear aliphatic diamine-based series of benzoxazine monomers has been studied under air and inert atmosphere. Differential scanning calorimetry is used to determine the melting points of these benzoxazines and the temperature of the peak polymerization exotherm. An anomalous polymerization behavior of ethylene diamine-based polybenzoxazine is also reported.

VISCOSITY AND EXCESS MOLAR VOLUME OF BINARY MIXTURES OF METHANOL AND ETHANOL WITH TRIETHYLAMINE AND TRI-N-BUTYLAMINE AT 303.15, 313.15, and 323.15 K: CHARACTERIZATION IN TERMS OF ERAS MODEL

The excess molar volume VE, viscosity deviation Δη, and excess Gibbs energy of activation ΔG*E of viscous flow have been investigated from the density ρ and viscosity η measurements of four binary mixtures of methanol and ethanol with triethylamine and tri-n-butylamine over the entire range of mole fractions at 303.15, 313.15, and 323.15 K. The viscosity data have been correlated with the equations of Grunberg and Nissan, Hind, McLaughlin, and Ubbelohde, Tamura and Kurata, and McAllister. The systems studied exhibit very strong cross association through strong O–H…N bonding between –OH and –N < groups. As a consequence of this strong intermolecular association, all four systems have very large negative VE. The VE of the studied mixtures is consistently described by the ERAS model. The values of cross association constants KAB illustrate the fact that cross-associates are more pronounced in a mixture of a short-chain tertiary amine.

Effective Intercalation and Exfoliation of Nanoplatelets in Epoxy via Creation of Porous Pathways

A new surface modification approach for improving intercalation and exfoliation efficiency of layered nanoplatelets is introduced on the basis of α-zirconium phosphate (α-ZrP) nanoplatelets. The intercalation of α-ZrP nanoplatelets was carried out using a number of different organic surface modifiers and their combinations. It is found that porous pathways, which can be created by incorporating a combination of a linear long-chain amine and a bulky, short-chain amine as intercalating agents, can lead to speedier and more effective intercalation. Consequently, fully exfoliated polymer nanocomposites can be more easily prepared. The intercalation/exfoliation mechanisms accounting for the observed effectiveness are discussed.