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The adsorption of hexylamine at the solution–gold interface in 1 M HClO4 in the presence of 0.1 M Fe2+ and 0.1 Fe3+ was studied by potentiodynamic, chronoamperometric and EIS methods. The main kinetic characteristics of the oxidation-reduction reaction iron ions (exchange current density, transfer coefficient, diffusion coefficients of iron ions) were determined. It was shown that the physical adsorption of hexylamine on gold can be described by the Dhar–Flory–Huggins isotherm. The values of the adsorption constant and the Gibbs free adsorption energy were obtained. A comparison of the free adsorption energy at these interfaces with the interaction energies of hexylamine and water molecules, and hexylamine molecules with each other was carried out. It was shown that hexylamine adsorption at all of these interfaces is due mainly to the hydrophobic effect of the interaction of hexylamine and water molecules.

Surface ligand engineering is of great importance for the preparation of one-dimensional (1D) CsPbBr3 nanowires for high-performance photodetectors. The traditional long-chain terminated ligands such as oleylamine/oleic acid (C18) used in the preparation of CsPbBr3 nanowires will form an electrically insulating layer on the surface of the nanowires, which hinders the effective transport of charge carriers in optoelectronic devices. In this paper, short-chain ligands, including dodecylamine/dodecanoic acid (C12), octylamine/octanoic acid (C8) and hexylamine/hexanoic acid (C6), are introduced to partially replace long-chain ligands (C18) to successfully prepare various CsPbBr3 nanowires via a solvothermal method. Microstructure characterization indicates that the four kinds of nanowires before/after surface ligand engineering, which are named as C18-CsPbBr3, C12/18-CsPbBr3, C8/18-CsPbBr3 and C6/18-CsPbBr3, all have high aspect ratio and purity. As compared with CsPbBr3 with long-chain terminated ligands, the C8/18-CsPbBr3 and C6/18-CsPbBr3 nanowires with shorter chain ligands exhibit superior photoluminescence (PL) performance and stability under adverse conditions such as ultraviolet irradiation and high temperature. The constructed photodetectors based on C8/18-CsPbBr3 and C6/18-CsPbBr3 nanowires have shown improved performances. This work provides a new idea for the preparation of CsPbBr3 nanowires with high optical properties, stability and charge transport, and the prepared CsPbBr3 nanowires have potential application prospects in optoelectronic devices.

Printed electronics implies the use of low-cost, scalable, printing technologies to fabricate electronic devices and circuits on flexible substrates, such as paper or plastics. The development of this new electronic is currently expanding because of the emergence of the internet-of-everything. Although lot of attention has been paid to functional inks based on organic semiconductors, another class of inks is based on nanoparticles obtained from exfoliated 2D materials, such as graphene and metal sulfides. The ultimate scientific and technological challenge is to find a strategy where the exfoliated nanoparticle flakes in the inks can, after solvent evaporation, form a solid which displays performances equal to the single crystal of the 2D material. In this context, a printed layer, formed from an ink composed of nano-flakes of TiS2 intercalated with hexylamine, which displays thermoelectric properties superior to organic intercalated TiS2 single crystals, is demonstrated for the first time. The choice of the fraction of exfoliated nano-flakes appears to be a key to the forming of a new self-organized layered material by solvent evaporation. The printed layer is an efficient n-type thermoelectric material which complements the p-type printable organic semiconductors The thermoelectric power factor of the printed TiS2/hexylamine thin films reach record values of 1460 µW m−1 K−2 at 430 K, this is considerably higher than the high value of 900 µW m−1 K−2 at 300 K reported for a single crystal. A printed thermoelectric generator based on eight legs of TiS2 confirms the high-power factor values by generating a power density of 16.0 W m−2 at ΔT = 40 K., Graphical abstract

Summary Two-dimensional (2D) perovskites with excellent stability and optoelectronic properties have aroused great interest for use in perovskite solar cells (PSCs). To date, the power conversion efficiencies (PCEs) of state-of-the art 2D-PSCs are non-satisfactory because of higher recombination losses in 2D quantum wells. Here, based on a series of alkylic ammonium spacers (ethylamine to hexylamine) with different chain lengths, we present a strategy via the molecular van der Waals interaction to realize modified crystallization, phase distribution, and quantum-confined behaviors in Ruddlesden-Popper 2D perovskites (n = 4). With the optimal amylamine (AA) spacer, high-quality 2D perovskites featuring well-aligned phase alignments with fewer unfavorable n-value species and a reduced exciton binding energy have been realized, leading to sufficient charge transfers through different n-value components. The devices based on (AA)2MA3Pb4I13 yield a champion PCE of 18.42%, showing an impressive open-circuit voltage of 1.25 V and a fill factor exceeding 0.80.

A novel stimulus-responsive non-Pickering emulsion stabilized by nano-SiO2 particles was prepared in our recent study. 4-formylbenzoic acid and hexylamine through a dynamic covalent bond form a surface-active substance, which was confirmed by Fourier transform infrared (FTIR) and 1H NMR. Through optimization experiments, it was proved that a stable emulsion can be formed by low surfactant concentration (below cmc) and low nano-SiO2 particle concentration (0.5 wt %). In this emulsion, nano-SiO2 particles are not located at the interface of oil-water but dispersed in the continuous phase of the emulsion, which is different from the Pickering emulsion. The negatively charged nano-SiO2 particles and anionic surfactants repel each other, thereby synergistically stabilizing the emulsion so that the concentrations of surfactants and nanoparticles required to stabilize the emulsion are reduced. In addition, the system can also control the formation and fracture of dynamic covalent bonds by changing pH, thereby controlling the stability and demulsification of the emulsion. At the same time, this non-Pickering emulsion could be used as a microreactor for chemical synthesis and still had a high yield after three cycles. This study provides a new application direction for this environmentally friendly emulsion.

Post-processable CH3NH3PbX3 (MAPbX3, X = Cl, Br, I, and their mixtures) metal halide perovskite nanocrystals (MHP NCs) for thin solid-film were synthesized by modified ligand-assisted re-precipitation method adopting MAPbX3, N,N-dimethylformamide (DMF), toluene, and oleic acid and hexylamine as MHP, good solvent, poor solvent, and co-ligands, respectively. Through simple optimization of the amount of DMF good solvent, the full colored MAPbX3 MHP NC-solid-films were formable. The self-powered panchromatic photodetectors were fabricated by depositing the post-processable blue, green, and red colored MAPbX3 MHP NCs on a mesoporous TiO2 film and the effective panchromatic photon harvesting were possible in a single cell.

Polypeptides have been widely utilized in the fields of biomaterials and biomedicine. Ever since N-carboxyanhydride (NCA) was reported by Hermann Leuchs in 1906, ring-opening polymerization of NCAs has been extensively used to prepare polypeptides. Despite continuous innovations, it is still challenging to synthesize polypeptides in high molecular weight efficiently. To address this challenge, we developed KHMDS/NaHMDS initiated fast NCA polymerization that is also moisture tolerant, open-flask amenable and terminal tunable. This NCA polymerization was able to proceed in most common solvents and meet the solubility requirement of variable NCA monomers and corresponding polypeptides. KHMDS can initiate γ-benzyl-L-glutamate-N-carboxyanhydride (BLG NCA) polymerization in a reaction rate 92 times faster than does hexylamine and 80 times faster than does triethylamine. This NCA polymerization also demonstrated easy and fast synthesis of gram-scale long chain polypeptides in an open flask.

Graphite oxide (GO) exhibits selective sorption of di-butylamine from a mixture of butylamine, di-butylamine and tri-butylamine. The selectivity is attributed to the higher basicity of di-butylamine in comparison to butylamine and tri-butylamine. Reaction of GO with a mixture of hexylamine and cyclohexylamine, two amines of similar basicity but different structures, suggests that in alkylamines, selectivity is predominantly due to the basicity of the amine with structural differences playing almost no role. However, when GO reacts with a mixture of aniline and cyclohexylamine (amines with a large difference in basicity) no selectivity is observed. The π-π interaction between the aromatic amine, aniline, and the aromatic regions of GO causes the sorption of aniline in its non-protonated form as much as cyclohexylamine with a far higher basicity.

The ongoing interest in all-inorganic cesium lead bromide perovskite nanocrystals (CsPbBr3 NCs) is mainly due to their optical properties, in particular their high photoluminescence quantum yields (PLQYs). Three-precursor synthetic methods, in which the sources of the three elements (cesium, lead and bromine) constituting the perovskite scaffold are chemically independent, often succeed in the achievement of near-unity PLQY perovskite NCs. However, this class of synthetic approaches precludes the accessibility to crystal morphologies different from the traditional cuboidal ones. In order to upgrade three-precursor synthetic schemes to obtain more sophisticated morphologies - such as rods - we propose a conceptually original synthetic methodology, in which a potentially controllable stage of the reaction anticipates the fast crystallization promoted by cesium injection. To this purpose, lead oxide, 1-bromohexane (at different molar ratios with respect to lead) and the ligands (oleic acid and a suitable amine) in 1-octadecene are reacted at 160 °C for an incubation period of 30 min before cesium injection. During this stage and at high C6H13Br/PbO molar ratios, the bromide release from reactions between the ligands and 1-bromohexane promotes the evolution of [PbBr(2+n)]n- species as well as of two-dimensional [(RNH3)2(PbBr4)]n structures with a rod-like shape (aspect ratios ∼10). These structures act as the templating agents for the subsequent crystallization promoted by cesium injection, ensuring the formation of near-unity PLQY nanorods in the presence of decylamine. Conversely, the pronounced decomposition of the preformed [(RNH3)2(PbBr4)]n structures preludes to the formation of near-unity PLQY nanocubes in the presence of hexylamine. The amine choice exerts also an important role in the emission stability of the corresponding NCs, since the nanocubes prepared in the presence of hexylamine maintain their near-unity PLQYs up to 90 days under ambient conditions. In addition to the long-term PLQY stability, the nanorods prepared with decylamine also exhibit a remarkable resistance to the presence of water, due to the compact and hydrophobic organic shell passivating the NC surface. These findings can contribute to the development of innovative synthetic methodologies for controlling the shape and stability of near-unity PLQY perovskite NCs.

We present herein the magnetic and Mössbauer investigation of a colorimetric chemical sensor with the chemical formula [Fe(H2btm)2(H2O)2]Cl2 (1) (H2btm = Di(1H-tetrazol-5-yl)methane). The spectra were recorded before and after sensing a series of toxic gases (MeOH, diethylenetriamine, hexylamine, 1,2-diaminocyclohexane, 3-picolylamine, pyridine and furfurylamine). Worth to note that the sensing process (color changes) proceeds at room temperature, does not require any pretreatment and can be detected as well by the naked eyes. 57Fe Mössbauer spectroscopy not only allows to identify the nature of spin states involved in our Fe(II) sensor but also to evaluate quantitatively the respective spin state population, i.e. high spin and low-spin states.

Enhanced As(III) removal (&gt, 99.7) was achieved by a novel organoclay (HEX-VER) adsorbent in Pearl River Delta water. Single and simultaneous As(III) removal in the presence of Cd(II) and/or Pb(II) by batch adsorption tests was analyzed. Spectroscopic, spectrometric, microscopic, and potentiometric techniques were used for characterization of the adsorbents. The parameters affecting As(III) adsorption, including pH, kinetic, isotherm, thermodynamic, and co-existing ions (Cl−, F−, NO3−, CO32−, SO42−, Ca2+ and Mg2+) were also investigated. The results showed that HEX-VER owned different morphology and larger average pore diameter after functionalization, resulting in an improvement of As (III) adsorption capacity. Further analysis confirmed that adsorption was of the monomolecular layer, well-described by the Langmuir isotherm model. The dominant mechanisms for As(III) removal were ion-exchange and complexation. Moreover, HEX-VER was regenerated for five consecutive cycles, and the removal ratio was ≈ 92%, showing its great regeneration potential. These findings suggest that the proposed inexpensive adsorbent has potential for practical applications of As(III) removal from river water.

The data on adsorbability of oleamides and hexylamine, cyclohexylamine, morpholine, piperidine, and piperazine salts of oleic acid are systematized in this study. The protective mechanism of these compounds is studied in order to reveal a correlation between the inhibiting ability and the calculated parameters of the molecules. A procedure for measuring the Volta potential difference using a Poverkhnost-II high-sensitivity digital electrometer under the conditions when water- and hydrocarbon-soluble corrosion inhibitors interact with the steel and copper surface is elaborated. It has been proven that a high-efficiency corrosion inhibitor can be designed based on the data on its donor properties and adsorbability.

We are the first to establish that the introduction of a small amount of passivating amine (Am) during the preparation of CH3NH3PbBr3 (MAPbBr3) (MA/Am = 0.7) leads to the formation of pseudo-2D nanoparticles of this hybrid perovskite, the number of layers in which decreases going from oleylamine to hexylamine. The use of a solution of polystyrene in toluene yields more homogeneous in size stabilized MAPbBr3 nanoparticles and alters the number of layers in them. The resultant MAPbBr3 dispersions and films have strong photoluminescence (PL), whose maximum is shifted toward higher energies in comparison with a powder of this hybrid perovskite due to a quantum size effect. Dispersions and films of MAPbBr3 prepared using oleylamine have the highest PL quantum yield (about 90%) due to the formation of 2D nanoparticles with ≥ 4 layers. An advantage of the MAPbBr3 samples prepared using hexylamine is increased color purity of the PL.

Solution processing of metal chalcogenides using elemental metals dissolved in an amine–thiol solvent mixture has recently received a great deal of attention for the fabrication of thin-film optoelectronic devices. However, little is known about the dissolution pathway for metallic precursors in such mixtures. To exploit the full potential of this method, it is essential that a detailed understanding of the dissolution chemistry be developed. In this study, we use several characterization techniques to examine these solutions and then propose reaction mechanisms for In and Cu dissolutions in a hexylamine/1,2-ethanedithiol mixture. These dissolutions are rather found to be reactions resulting in metal oxidation with coevolution of H2 forming bis(1,2-ethanedithiolate)indium(III) in the case of indium dissolution and high nuclearity Cu(I) thiolate compounds in case of copper dissolution. This understanding allowed us to address the issue of toxicity and corrosivity associated with amine–thiol solvent by util...

The aim of the present research was to study the impact of six various ion-pairing reagents in ion pair chromatography mode on both retention and ionization of seven antisense oligonucleotides which have the same sequence but different types of modifications and length. Furthermore, retention and selectivity studies were performed with the use of four different stationary phases, including octadecyl, octyl, and pentafluorophenyl groups as well as ligands with embedded polar groups. The results of the research showed that the main factors influencing the retention of the studied compounds are amine hydrophobicity and chain branching. The greatest retention was obtained for hexylamine, while the lowest for propylamine. Octadecyl and pentafluorophenyl columns were characterized by the best selectivity and the former was selected for further investigation. What is more, tandem mass spectrometry parameters were optimized and the sensitivity of oligonucleotide mass spectrometry determination was assessed. The greatest sensitivity was obtained for 5 mM N,N-dimethylbutylamine combined with 1,1,1,3,3,3-hexafluoroisopropanol and methanol. The developed method was successfully applied for the determination and separation of the mixture of seven different oligonucleotides in fortified serum, which was completed in 8 min. The LOQ values of the developed method were in the range of 0.15–0.56 µM (0.91–3.56 ng on column). Moreover, it has to be highlighted that it was the first time that such comprehensive investigations were carried out for various types of oligonucleotide modifications and for different stationary phases as well as ion pair reagents.

Cooperative interactions and transitions are among the most important strategies utilized by biological systems to regulate a variety of physical and chemical processes. We report herein an auto-accelerated, rapid cooperative polymerization of N-carboxyanhydrides (NCAs) with initiators structurally as simple as linear aliphatic diamines for the synthesis of polypeptides. The polymerization initiated by diamines proceeds via the formation of "hinged" polypeptides, which are two blocks of helical chains connected head-to-head by the diamine molecules in the polymerization solution. The reactions follow a two-stage, cooperative polymerization kinetic; the cooperative interactions between the macrodipoles of the two hinged helical polypeptides dramatically accelerate the polymerization. Compared to the NCA polymerization initiated by the hexylamine (CH3(CH2)5NH2), the chain propagation rate of the NCA polymerization is increased by more than 600 times when initiated by its diamine analogue (1,6-diaminohexane, NH2(CH2)6NH2). This proximity-induced cooperative polymerization showcases the single helix as a remarkable cooperativity-enabling motif in synthetic chemistry.

Amphiphilic carbon-based nanoparticles have recently attracted much attention in stabilizing Pickering emulsions owing to their low cytotoxicity, cost-effectiveness and biocompatibility. In this work, a facile and aqueous synthesis method was developed for the preparation of amphiphilic graphene quantum dots by modifying hydrophilic GQDs (GQDs-COOH) with hydrophobic hexylamine. Distinctive from pristine GQDs-COOH, amphiphilic GQDs show interesting surface-active properties and can stabilize water-in-cyclohexane Pickering emulsions. As efficient particle surfactants, amphiphilic GQDs could be applied in a mini-emulsion polymerization system to synthesize submicron-sized polystyrene particles. Particularly, the as-prepared PS particles were highly luminescent as produced by the highly fluorescent amphiphilic GQDs.

Adsorption of 5,10,15,20-tetraphenyl-21H,23H-porphyrin cobalt (CoTPP) on mica immersed in organic solvents of 1-hexanol, 1-chlorohexane, and 1-phenyloctane was examined. Flat-lying CoTPP molecules were recognized in topographic images observed by atomic force microscopy. The topographic height of individual porphyrins fluctuated by 0.2 nm in a time scale of 10 s. The height fluctuation was ascribed to two states with and without a solvent molecule trapped in the axial ligand position of the CoTPP. In imaging in phenyloctane, adsorbed CoTPPs were removed by adding 1-hexylamine to the imaging solution. Hexylamine ligands would have occupied the axial position of CoTPP to hinder adsorption. In addition, two-dimensional distribution of force pushing the tip was observed in hexanol to show a layered liquid structure parallel to the mica surface.

Despite the powerful nature of the aza-Michael reaction for generating C–N linkages and bioactive moieties, the bis-Michael addition of 1° amines remains ineffective for the synthesis of functional, step-growth polymers due to the drastic reduction in reactivity of the resulting 2° amine mono-addition adduct. In this study, a wide range of commercial hydrazides are shown to effectively undergo the bis-Michael reaction with divinyl sulfone (DVS) and 1,6-hexanediol diacrylate (HDA) under catalyst-free, thermal conditions to afford moderate to high molecular weight polymers with M(n) = 3.8–34.5 kg mol(-1). The hydrazide-Michael reactions exhibit two distinctive, conversion-dependent kinetic regimes that are 2(nd)-order overall, in contrast to the 3(rd)-order nature of amines previously reported. The mono-addition rate constant was found to be 37-fold greater than that of the bis-addition at 80 °C for the reaction between benzhydrazide and DVS. A significant majority (12 of 15) of the hydrazide derivatives used here show excellent bis-Michael reactivity and achieve >97% conversions after 5 days. This behavior is consistent with calculations that show minimal variance of electron density on the N-nucleophile among the derivatives studied. Reactivity differences between hydrazides and hexylamine are also explored. Overall, the difference in reactivity between hydrazides and amines is attributed to the adjacent nitrogen atom in hydrazides that acts as an efficient hydrogen-bond donor that facilitates intramolecular proton-transfer following the formation of the zwitterion intermediate. This effect not only activates the Michael acceptor but also coordinates with additional Michael acceptors to form an intermolecular reactant complex.

Hybrid quasi-two dimensional perovskites (2D) have attracted significant scientific interest, because they have been demonstrated to be excellent light absorbing materials in photovoltaic devices. However, quasi-2D perovskites still perform poorly in high humidity, even though they have exhibited greatly improved stability compared to their three-dimensional (3D) counterparts. This is the biggest obstacle for the practical implementation and commercial viability of perovskite solar cells. Herein, we used hexylamine (CH3(CH2)4CH2NH2, HA) for a quasi-2D, HA(CH3NH3)n−1PbnI3n+1 (n = 1, 2, 3, 4) perovskite, which had sufficiently long alkyl chains to maintain the chemical stability of the perovskite. As the number of layers of quasi 2D HA(CH3NH3)n−1PbnI3n+1 perovskites was increased, they exhibited an appropriate band gap as a light absorber to be applied in solar cells. The perovskite solar cell based on the 2D HA(CH3NH3)n−1PbnI3n+1 perovskites showed an excellent power conversion efficiency of 5.90% with a short circuit current density of 13.61 mA cm−1, an open circuit voltage of 0.72 V, a fill factor of 60.10%, and stability in ambient air. The long alkyl chain of the hexylamine cation prevented the degradation of the solar cell in the atmosphere with passivation of the perovskite films due to their high hydrophobic properties. This investigation highlights the role of the organic cation in maintaining the quality of the perovskite film and provides a critical solution for the poor stability of perovskites in ambient air.

A simple and low-cost method is proposed to synthesize graphene oxide incorporated with silver nanoparticles. The inter-sheet distance was controlled by introducing hexylamine into the graphene oxide sheets. The materials were investigated by Raman, UV-vis and Fourier transform infrared spectroscopy, X-ray diffraction and field-emission scanning electron microscopy. The increase in inter-sheet distance, due to the presence of hexylamine, favored the growth of the silver nanoparticles within the sheets. We demonstrate that silver nanoparticles increased the electrical conductivity and capacitive properties of the graphene oxide based electrode. The high concentration of well dispersed silver nanoparticles on the surface of the graphene sheets resulted in ca. 90 times higher specific capacitance than bare graphene oxide, in addition to improved electrochemical activity. The proposed method is promising for the development of hybrid materials with enhanced properties for applications mainly in electrochemical energy storage devices.

For traditional photocatalysts, the adsorption and successive surface reaction constitute a coupled and integrated process, owing to the limited number of catalytic active centres available. An attempt to boost the photocatalytic performance to optimize the adsorption and surface reaction process may be performed by exploring various photocatalyst infrastructures. Herein, we use a facile solvothermal method to synthesize a series of layered alkylammonium thiostannate hybrids, namely (baH)2Sn3S7, (haH)2Sn3S7 and (oaH)2Sn3S7 (ba = butylamine, ha = hexylamine, oa = octylamine). The hybrids showed broad UV-visible light absorption with appropriate band gaps. The inorganic/organic amphiphilic infrastructure of these hybrids enables them to exhibit prominent ion-exchange properties for Rhodamine B, with a large capacity over a wide pH range (1–11). And the adsorbed Rhodamine B is photodegraded within 30 minutes. A mechanistic study indicates that the adsorption and photodegradation steps are performed at the organic and inorganic layers within these hybrids, respectively, which are decoupled and independent. We conclude that the high-performance integrated adsorption–photodegradation ability is a consequence of the lipophilicity of intercalated alkylammonium and the photocatalysis performance of the 2D [Sn3S7]n2n− monolayers.

The hydrogenation of amides is a straightforward method to produce (possibly bio-based) amines. However current amide hydrogenation catalysts have only been validated in a rather limited range of toxic solvents and the hydrogenation of aliphatic (acyclic) primary amides has rarely been investigated. Here, we report the use of a new and relatively cheap ruthenium–tungsten bimetallic catalyst in the green and benign solvent cyclopentyl methyl ether (CPME). Besides the effect of the Lewis acid promotor, NH3 partial pressure is identified as the key parameter leading to high primary amine yields. In our model reaction with hexanamide, yields of up to 83% hexylamine could be achieved. Beside the NH3 partial pressure, we investigated the effect of the catalyst support, PGM-Lewis acid ratio, H2 pressure, temperature, solvent tolerance and product stability. Finally, the catalyst was characterized and proven to be very stable and highly suitable for the hydrogenation of a broad range of amides.

International audience; Supramolecular zwitterionic silicones are synthesized by aza-Michael reaction between acrylic acid and amine-functional polydimethylsiloxanes. The in-depth characterization of this chemistry, applied for the first time to silicones, is investigated first with model alkylamines (hexylamine, 2-ethylhexylamine and N-propylethylenediamine), a model oligosiloxane (3-aminopropylmethyl bis(trimethylsiloxy)silane), and finally various amino-polysiloxanes. It is shown that after a first acid-base reaction resulting in ionic pairing, aza-Michael addition proceeds smoothly in mild conditions (50 degrees C, 1-week reaction). Both monoadducts and di-adducts, together with residual amine, are observed by NMR. The supramolecular assembly of the thus-created zwitterionic moieties is highlighted by a concomitant increase in viscosity and phase separation, as observed by transmission electron microscopy, bringing an additional glass transition at -40 degrees C assigned to highly polar ionic clusters. Below the stoichiometry in acrylic acid, all zwitterionic silicones follow the same classical behavior of nonentangled polymers according to the Rouse model, whereas upon introducing an excess of acrylic acid to amino groups, an enhancement of the elasticity is observed. Finally, silicone elastomers with solid-like behavior and elastomeric mechanical properties are obtained using a high molar mass polymer bearing bifunctional N-(2-aminoethyl)-3-aminopropyl units that favor a high degree of physical crosslinking.

In this paper, we describe both new as well as described in our previous works 1,8-naphthalimide derivatives substituted at the 3-C position with imine or β-ketoenamine unit in order to demonstrate a broader scope of research enabling of analysis between the structure-properties relationship relevant to the application of these compounds in organic electronics and cellular imaging. Thermal, physicochemical, optical, electrochemical, electroluminescence, and biological properties of a series of derivatives containing the 1,8-naphthalimide unit were tested and compared. This allowed the determination of the impact of substituents in the imide part (hexylamine, phenylethyl, benzyl, fluorobenzyl, methylbenzyl), type of bond (imine or ketoenamine) as well as the substituent on the naphthalene ring (2-hydroxyphenyl, 5-bromo-2-hydroxyphenyl, 3,5-diodo-2-hydroxyphenyl, pyrimidines) on their properties. Moreover, the properties in the aggregating state were tested in the MeOH/PBS system. Imines are susceptible to the hydrolysis process and aggregation-caused photoluminescence quenching (ACQ). In turn, β-ketoenamine shown excited-state intramolecular proton transfer promoted by aggregation (AIEE). Our studies can be helpful in the further design of compounds containing the 1,8-naphthalimide structure for various applications.

In this study, we performab initiocalculations, using density functional theory, to provide more insights about the role of alkane chain in primary amine capped (CdSe)33and (CdS)33quantum dots (QDs). We passivate the QDs surfaces with seven primary amines of different carbon chain lengths starting from NH3to hexylamine. The primary amine ligands induce a blue shift in the band gap of the ligated QDs, in agreement with experimental studies, but the alkane chain itself show negligible changes in the band gap. By increasing the chain length the binding energy between ligands and the QDs increases but its rate decreases due to the increase of steric hindrance between the ligands. The role of van der Waals forces in such behavior is found to be notable which is done by performing geometry optimization through adding and neglecting the dispersion correction effects for each system. The results of this study can provide helpful information for ligand selectivity in controlling the size and properties of the QDs using primary amines.

Silica aerogels have attracted much attention owing to their excellent thermal insulation properties. However, the conventional synthesis of silica aerogels involves the use of expensive and toxic alkoxide precursors and surface modifiers such as trimethylchlorosilane. In this study, cost-effective water-glass silica aerogels were synthesized using an eco-friendly catechol derivative surface modifier instead of trimethylchlorosilane. Polydopamine was introduced to increase adhesion to the SiO2 surface. The addition of 4-tert-butyl catechol and hexylamine imparted hydrophobicity to the surface and suppressed the polymerization of the polydopamine. After an ambient pressure drying process, catechol-modified aerogel exhibited a specific surface area of 377 m2/g and an average pore diameter of approximately 21 nm. To investigate their thermal conductivities, glass wool sheets were impregnated with catechol-modified aerogel. The thermal conductivity was 40.4 mWm&minus, 1K&minus, 1, which is lower than that of xerogel at 48.7 mWm&minus, 1. Thus, by precisely controlling the catechol coating in the mesoporous framework, an eco-friendly synthetic method for aerogel preparation is proposed.

Copper sintering is gaining prominence as a prospective alternative to silver sintering in die-attach applications. However, process temperatures and sintering times are still high compared to silver sintering and a challenge for large scale industrialization. In this paper, rapid and low temperature die-attach bonding using copper formate based inks is investigated. While these inks are successfully used to form metal traces on substrates by inkjet and aerosol printing, they reveal a substantial challenge for die-attach bonding. Based on results using polyethylene glycol (PEG) as binder, different pastes were realized and investigated using binders which form metal complexes with copper formate. Beside the promising result using PEG, best bonding results were obtained using α- terpineol as binder while traditional conductive ink binders amino-2-propanol and hexylamine caused challenges during pre-drying, degassing and in establishing a reliable interconnect.

The influence of addition of amines (hexylamine, tripropylamine, dodecylamine, and hexadecylamine) and dopants (Zr, Ce) on the properties of mesostructured aluminas (MAs) synthesized using either Tergitol 15-S-9 or Triton X-114 surfactants was investigated. Selected MAs were evaluated as supports for Co and Ru-Co catalysts and their Fischer-Tropsch synthesis (FTS) performance assessed at 493 K, 2.0 MPa, and H/CO = 2. The materials were characterized by XRD, N sorption, TG-DTG, EA, XPS, H-TPR, H chemisorption, and STEM. Regardless of the surfactant, all amines enlarged the pore size of undoped MAs by ca. 2–3 nm. The impact of amines on BET area and pore volume depended, however, on the surfactant-amine combination and on the presence and concentration of dopants. The Ru-promoted catalyst supported on the MA synthesized with Tergitol-tripropylamine doped with Zr displayed the highest FTS activity and C selectivity due to both high cobalt reducibility and optimum particle size (8 nm)., A. M. acknowledges the MINECO of Spain for financial support through the project RTI2018-102161. C. M.-A. and J. P.-P. also acknowledge MINECO for funding (project MAT2016-77496-R). S. M. acknowledges the organization of student affairs (Iran) for a sabbatical leave grant. The authors are thankful to the Microscopy Service of the Universitat Politècnica de València for its assistance in microscopy characterization.

Sooting tendencies of a series of nitrogen-containing hydrocarbons (NHCs) have been recently characterized experimentally using the yield sooting index (YSI) methodology. This work aims to identify soot-relevant reaction pathways for three selected C6H15N amines, namely, dipropylamine (DPA), diisopropylamine (DIPA), and 3,3-dimethylbutylamine (DMBA) using ReaxFF molecular dynamics (MD) simulations and quantum mechanical (QM) calculations and to interpret the experimentally observed trends. ReaxFF MD simulations are performed to determine the important intermediate species and radicals involved in the fuel decomposition and soot formation processes. QM calculations are employed to extensively search for chemical reactions involving these species and radicals based on the ReaxFF MD results and also to quantitatively characterize the potential energy surfaces. Specifically, ReaxFF simulations are carried out in the NVT ensemble at 1400, 1600, and 1800 K, where soot has been identified to form in the YSI experiment. These simulations account for the interactions among test fuel molecules and pre-existing radicals and intermediate species generated from rich methane combustion, using a recently proposed simulation framework. ReaxFF simulations predict that the reactivity of the amines decrease in the order DIPA > DPA > DMBA, independent of temperature. Both QM calculations and ReaxFF simulations predict that C2H4, C3H6, and C4H8 are the main nonaromatic soot precursors formed during the decomposition of DPA, DIPA, and DMBA, respectively, and the associated reaction pathways are identified for each amine. Both theoretical methods predict that sooting tendency increases in the order DPA, DIPA, and DMBA, consistent with the experimentally measured trend in YSI. This work demonstrates that sooting tendencies and soot-relevant reaction pathways of fuels with unknown chemical kinetics can be identified efficiently through combined ReaxFF and QM simulations. Overall, predictions from ReaxFF simulations and QM calculations are consistent, in terms of fuel reactivity, major intermediates, and major nonaromatic soot precursors.

Density, ρ, speed of sound, u, and the difference in the temperature before and after the mixing process , ΔT, were measured for binary mixtures containing of cyclohexanol (CYC) + diethanolamine (DEA) or triethanolamine (TEA) or butylamine (BUT) or hexylamine (HEX) at (303.15–318.15) K except ΔT at 303.15 K. The excess molar volume, V m E , excess partial molar volume, V m , i E , excess thermal expansion coefficient, α E , isothermal coefficient of excess molar enthalpy, ( ∂ H m E ∂ P ) T , x , deviation in isentropic compressibility, Δ κ s , excess molar enthalpy, H m E , and excess partial molar enthalpy, H m , i E , were also calculated. The calculated data were satisfactorily correlated by Redlich – Kister equation. Some empirical models such as (Prigogine–Flory–Paterson) PFP, Wilson, (Non-Random Two Liquid) NRTL and (universal quasi chemical) UNIQUAC. Computational methods were performed using density function theory (DFT) and molecular dynamics (MD) simulation and were used to discuss and compare intramolecular and intermolecular interactions. An acceptable agreement was found between empirical and theoretical data.

Hydrophilic metabolites are essential for all biological systems with multiple functions and their quantitative analysis forms an important part of metabolomics. However, poor retention of these metabolites on reversed-phase (RP) chromatographic column hinders their effective analysis with RPLC-MS methods. Herein, we developed a method for detecting hydrophilic metabolites using the ion-pair reversed-phase liquid-chromatography coupled with mass spectrometry (IPRP-LC-MS/MS) in scheduled multiple-reaction-monitoring (sMRM) mode. We first developed a hexylamine-based IPRP-UHPLC-QTOFMS method and experimentally measured retention time (tR) for 183 hydrophilic metabolites. We found that tRs of these metabolites were dominated by their electrostatic potential depending upon the numbers and types of their ionizable groups. We then systematically investigated the quantitative structure-retention relationship (QSRR) and constructed QSRR models using the measured tR. Subsequently, we developed a retention time predictive model using the random-forest regression algorithm (r2 = 0.93, q2 = 0.70, MAE = 1.28 min) for predicting metabolite retention time, which was applied in IPRP-UHPLC-MS/MS method in sMRM mode for quantitative metabolomic analysis. Our method can simultaneously quantify more than 260 metabolites. Moreover, we found that this method was applicable for multiple major biological matrices including biofluids and tissues. This approach offers an efficient method for large-scale quantitative hydrophilic metabolomic profiling even when metabolite standards are unavailable. We acknowledge financial supports from the Ministry of Science and Technology of China (2018YFE0201603, 2020YFE0201600 and 2017YFC0906800), Shanghai Municipal Science and Technology Major Project (2017SHZDZX01), and the National Natural Science Foundation of China (81590953 and 31821002).

The wettability of the coating used in controlled release fertilizers (CRFs) is a crucial parameter for the release behavior of nutrients. However, how to control the wettability of coating to tune nutrient release is a big challenge. Herein, the alkylamine-poly (tannic acid) (APTA) building blocks coatings with controlled wettability were prepared as coating materials for CRFs. Alkylamine (octadecylamine (ODA), hexadecylamine (HDA), dodecylamine (DDA), and hexylamine (HEA)) were applied for the modification of poly (tannic acid) (PTA) coating on the silicon wafer and urea surface. The wettability of coatings on silicon wafers were studied and nutrient release of APTA coated fertilizers were characterized in water and soil. The nitrogen nutrient and water vapor permeability coefficient of coatings were characterisized and the mathematical model for predicting the release of nutrients in soil. The alkyl chain length of alkylamine is demonstrated to play a crucial part in controlling the wettability. The rate of nutrient release increases in the order of ODA-PTA

In order to accurately analyze how the surfactant attached on the surface of the nanoparticles affects the catalytic activity, all other experimental conditions should be maintained except the surfactant. In this study, we control the hydrocarbon chain length of the alkylamine and carboxylic acid on the surface of manganese oxide (Mn3O4) nanoparticles while keeping their size and shape using a reverse micelle method. Despite the use of various lengths of surfactants, the size and shape of the synthesized nanoparticles remain virtually unchanged. After the mild heattreatment, they have different secondary particle morphologies even though the nano particles are preserved. Those prepared nanoparticles exhibit the characteristics voltage behavior under the galvanostatic charge and discharge. The obtained electrochemical performances are influenced by the surfactants. A coin cell having Mn3O4 nanoparticles coated by hexanoic acid and hexylamine shows the highest capacity than the other samples.

A simple and selective derivatization and detection method for o-toluidine, o-anisidine, and 2,4-dimethylaniline was developed using a sulfuric acid impregnated filter, 4-(N-chloroformylmethyl-N-methylamino)-7-nitro-2,1,3-benzoxadiazole, and a surrogate (o-ethylaniline), which allowed simple, rapid, selective, and identifiable analysis by high-performance liquid chromatography with fluorescence detection. These amines were successfully derivatized in a pH 5 buffer solution containing acetonitrile at 35°C for 10 min (linear in the range 0-400 ng/mL, n = 5, aromatic amines: r > 0.9980, aromatic amines with surrogate correction: r > 0.9997, aromatic amines in the presence of phenol and aliphatic amines with surrogate correction: r > 0.9996). The retention times of these derivatized aromatic amines were