Alkyl Carbon Research Articles

Hydrogen bond liquid cystals formed between pentyloxy benzoic acid and alkyl benzoic acids: chemical, optical, and thermal investigations

Chemical, optical, and thermal characterization are carried out for seven hydrogen bond thermotropic liquid crystalline complexes formed between pentyloxy benzoic acid (5BAO) and p-n-alkyl benzoic acids (nBA, where n refers alkyl carbon chain length which varies from ethyl to octyl. FTIR, 1H, and 13C Nuclear Magnetic Resonance (NMR) establishes the chemical investigations. Nematic and smectic F are the mesophases observed. Polarizing Optical Microscopic (POM) studies ensures the mesophases identified. Thermal investigation using Differential Scanning Calorimeter (DSC), provides the phase transition temperatures, enthalpy values, thermal stability factor, specific heat capacity values, and thermal equilibrium of the mesogenic complexes.

Theoretical and experimental analysis of CO2 capture into 1,5-diamino-2-methyl-pentane/n-propanol non-aqueous absorbent regulated by ethylene glycol

The non-aqueous amine solvents for CO2 capture gaine an advantage in energy-saving potential, but with a sharp increase viscosity after saturated absorption would easily cause problems such as equipment scaling and pipe blockage. In the present work, the ethylene glycol (EG) was used as co-solvent and activator to regulate the non-aqueous absorbent of 1,5-diamino-2-methyl-pentane (DA2MP) and n-propanol (PrOH) for CO2 capture. The absorption loading of the mixture solution was 1.13 mol·mol−1 when the mass concentration of DA2MP was 25 wt% and the volume ratio of PrOH to EG was 8:2. By activated by EG, the viscosity of the saturated solution was only 9.05 mPa·s, which changed from viscous precipitation to clarify liquid compared with that of DA2MP/PrOH. The absorbent maintained 90.30% of its initial CO2 absorption loading after 10th cycle regeneration under 393.15 K for 60 min. According to the quantum chemical calculations and experimental results, the reaction and regulation mechanism of CO2 capture into DA2MP/PrOH/EG was clarified. In DA2MP-PrOH solution, CO2 firstly reacted with DA2MP to form carbamate, and them the product further reacted with PrOH to form alkyl carbonates, which was viscous and insoluble due to the high intermolecular force between the CO2 products. After adding appropriate amount of EG, the solubility of insoluble products in solvent was increased through weakening the intermolecular interaction of products and enhancing the intermolecular interaction between products and solvents, which further converted them into soluble alkyl carbonate and realized viscosity reduction. The regeneration heat duty of DA2MP/PrOH/EG solution was estimated as 1.58 GJ·ton−1 CO2, which was 29.5% and 58.42% less than that of DA2MP/PrOH and bench mark MEA solution, respectively, indicating a alternative candidate for CO2 capture.

Distinct dynamics of plant- and microbial-derived soil organic matter in relation to varying climate and soil properties in temperate agroecosystems

Global environmental change can substantively alter soil carbon storage and dynamics in agroecosystems. However, investigations of soil organic matter (OM) composition associated with various environmental factors are still limited, and this hinders the understanding of soil carbon biogeochemistry in agricultural settings. Soil samples were collected at two times (time 0 and 8 or 10 years) from 10 agricultural sites across Canada and New Zealand with varying soil properties (i.e., soil texture, pH) and climates (MAT, mean annual temperature; MAP, mean annual precipitation). The soils were analyzed for organic carbon, nitrogen and soil OM composition using molecular-level techniques that included targeted compound-specific and solid-state 13C nuclear magnetic resonance analyses. Soil carbon contents were similar over time and were not correlated with environmental factors. Molecular-level characterization of soils found that the preservation and degradation of specific soil OM components differed. Simple sugars and microbial-derived compounds (i.e., fungi-derived ergosterol and microbial-derived lipids) persist less with time in soils compared to other OM components. However, the increased cutin- and suberin-derived compounds at most sites and similar alkyl carbon contents with time suggested that cutin- and suberin-derived compounds were longer-lived compared to other soil OM compounds. Correlation analyses indicated that temporal differences in fungal-derived ergosterol were positively correlated with silt content (r = 0.78). An inverse correlation was observed between lignin degradation and silt content (r = −0.75). Cutin- and suberin-derived compounds were negatively correlated with MAT (r = −0.69); when the analysis was restricted to only Canadian sites, cutin- and suberin-derived compounds and their degradation were correlated with MAP and MAT (climate variables). Further, partial correlation analysis revealed that the correlations between soil texture and the temporal shifts in soil OM composition were indirectly regulated by MAP but not MAT. Overall, distinct environmental constraints were observed for specific OM components in agroecosystems, suggesting that the preservation mechanisms are not uniform across a wide range of soils under different climates and soil properties.

Photoinduced Pyridine N‐oxides Catalyzed Carbon Radical Generation from Alkylboronic Acids

AbstractHerein we report a protocol for the generation of alkyl carbon radicals from alkylboronic acids wherein photoexcited 4‐nitropyridine N‐oxide biradical features a catalyst to promote the nucleo‐homolytic substitution of boronic acids. With a wide range of readily available aliphatic boronic acids, including methyl boronic acid, the developed catalytic system demonstrates broad applicability for alkylation, amination, and cyanation.

Influence mechanism of Fe(II/III) doping on the adsorption of methylamine salts on kaolinite surfaces elucidated through DFT calculations

To investigate the effect of Fe(II/III) doping on the microscopic mechanism of methylamine salt hydrophobic modifiers on kaolinite surfaces, the adsorption characteristics of various methylamine cations on Fe(II/III)-doped kaolinite (denoted as Fe(II/III)-Kao) surfaces are calculated by density functional theory (DFT). The simulation results, including the Fukui index, adsorption energy, Mulliken bond populations, and charge analysis, reveal that Fe(II/III) doping enhances the surface activity of kaolinite, with significant effects observed in proximity to the doping site. Consequently, Fe(II/III) doping strengthens the interaction between methylamine cations and kaolinite surfaces. The adsorption mechanism of various methylamine cations on Fe(II/III)-Kao surfaces is attributed to a combination of hydrogen bonding and electrostatic attraction, with electrostatic attraction dominating the adsorption process. By comparing the adsorption energy of methylamine cations and alkyl carbon chains on Fe(II/III)-Kao surfaces, it becomes evident that the alkyl carbon chain has minimal impact on the adsorption of the hydrophobic modifier on Fe(II/III)-Kao surfaces. This finding confirms that the ammonium salt hydrophobic modifier primarily adsorbs onto Fe(II/III)-Kao surfaces through its polar head groups. The research results establish a theoretical foundation for further investigations on fine clay particle interface control and hydrophobic modifier design, ultimately guiding practical production processes.

Excited-State Odd-Even Effect in Through-Space Interactions.

The odd-even effect is a fantastic phenomenon in nature, which has been applied in diverse fields such as organic self-assembled monolayers and liquid crystals. Currently, the origin of each odd-even effect remains elusive, and all of the reported odd-even effects are related to the ground-state properties. Here, we discover an excited-state odd-even effect in the through-space interaction (TSI) of nonconjugated tetraphenylalkanes (TPAs). The TPAs with an even number of alkyl carbon atoms (C2-TPA, C4-TPA, and C6-TPA) show strong TSI, long-wavelength emission, and high QY. However, the odd ones (C1-TPA, C3-TPA, C5-TPA, and C7-TPA) are almost nonexistent with negligible QY. Systematically experimental and theoretical results reveal that the excited-state odd-even effect is synthetically determined by three factors: alkyl geometry, molecular movability, and intermolecular packing. Moreover, these flexible luminescent TPAs possess tremendous advantages in fluorescent information encryptions. This work extends the odd-even effect to photophysics, demonstrating its substantial importance and universality in nature.

Effects of structures of lower aliphatic alcohols and concentrations on CO2 chemical absorption and desorption reactions in various alcohol solutions of 1,8-diazabicyclo[5.4.0]undec-7-ene

Alcohol solutions of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) have received considerable interest as chemical absorbers of CO2 and switchable solvents because of their reversible reaction with CO2 and the polarity change triggered by CO2 absorption/desorption. However, there have been only a few systematic studies on the CO2 absorption and desorption behaviors of DBU–alcohol solutions. In this study, we determined the solubility of CO2 in binary solutions of DBU and various lower aliphatic alcohols at different temperatures. Except for the 2-methyl-2-propanol solution, which showed very low reactivity with CO2, all the DBU–alcohol solutions exhibited almost the same solubilities of CO2 at 298.2 K, independent of the alkyl groups present on the alcohols. However, their solubilities varied with DBU concentration. Moreover, we examined the amounts of CO2 recovery from the CO2-saturated solutions at high temperatures up to 393.2 K or the boiling points. The amount of CO2 per mole of DBU desorbed by heating was markedly influenced by both the alkyl group on the alcohols and the DBU concentration, indicating that at the studied concentrations, the temperature dependence of CO2 solubilities is strongly affected by the type of alcohol. To clarify this unique desorption behavior, we measured the 1H, 13C, and 15N nuclear magnetic resonance spectra of the DBU–alcohol solutions with and without CO2 at 298.2 K. In the absence of CO2, the nitrogen atoms at the 8-position of the DBU molecules strongly interact with the hydroxyl hydrogen atoms of the alcohol molecules via hydrogen bonding. As the DBU–alcohol solutions were saturated with CO2, the formation of protonated DBU ([DBUH]+) and alcohol-CO2 adduct (alkyl carbonate, [ROCO2]–) was confirmed. [DBUH]+ is stabilized by the solvation of free alcohol molecules, and the reverse reaction of [DBUH]+ with [ROCO2]– for CO2 release is hindered. Our findings are beneficial for designing and tuning DBU–alcohol systems for CO2 separation.

Tracing the Powerfade: Location and Quantification of the Fluoridic Solid Electrolyte Interphase on Graphite Anodes

Due to the conversion of the global energy supply from carbon emitting to renewable sources, there is the need for energy storage systems being efficient at high energy- and power densities. Many requirements are fulfilled best by Lithium-Ion Batteries (LIBs), so this technology is successfully part of battery-electric vehicles, cordless power tools and portable electronic devices. The ongoing improvement of anode- and cathode materials, together with adapted electrolytes [1] led to excellent advances in power- and energy densities. However, the increasing amount of total energy per cell underlines the importance of monitoring the cell’s health parameters (e.g. capacity fades, coulombic efficiencies, AC-and DC-impedances) in order to ensure safety and expand the lifetime [2, 3]. The Solid Electrolyte Interphase (SEI) represents a main source for cell impedances [4] and was in the case of LiPF6-based electrolytes found to be best analytically accessible by the quantitative determination of its unsolvable, fluoridic fractions (LiF) using ion-exchange chromatography [5].During this work, long term cycling tests (T = 25, 40, 60 °C, 2 C charging) of industrial 3 Ah-21700-cells with graphite anode (figure a), NMC 811 cathode and LiPF6-based electrolyte were performed (figure b). Subsequently, after defined cycling steps (10, 250, 500, 750 cycles) the cells were opened, post-mortem analysis (SEM, EDX, “broad ion beam”- (BIB) preparation) together with the drawing of anode/separators samples for the later fluoride determination took place. The samples were cleaned from LiPF6 (washing with DEC) and dried under glovebox conditions (Ar, < 0.5 ppm H2O). With the aim to quantify the SEI layer 1) in the anode bulk and 2) adhering to or inside the separator to trace reversible Li-plating, anode/separators samples were eluted separately with deionized water and the fluoride-concentration of the solutions was determined by ion-exchange chromatography (figure c - f). SEI fractions, like inorganic carbonates, alkyl carbonates, oxides, etc., were investigated using X-ray photoelectron spectroscopy (XPS) along a depth profile (figure g) using Ar-ion sputtering [6, 7].The results elaborated within this study point out a strong correlation in between the amount of fluoridic SEI and the DC-impedance rise during cycling, especially at elevated temperatures (40, 60 °C). At 25 °C different ageing mechanisms are obvious: In comparison lower fluoride concentrations together with substantial DC impedance gains suggest the temporary and superficial occurrence of reversible Li-plating, blocking important Li-ion paths via the electrolyte (e.g. anode surface pores, separator pores [8, 9]) by residual products of their SEI-films. Reference s [1] Eshetu, G. G.; Zhang, H.; Judez, X.; Adenusi, H.; Armand, M.; Passerini, S.; Figgemeier, E., Production of high-energy Li-ion batteries comprising silicon-containing anodes and insertion-type cathodes. Nat Commun 2021, 12, (1), 5459.[2] Sternad, M.; Cifrain, M.; Watzenig, D.; Brasseur, G.; Winter, M., Condition monitoring of Lithium-Ion Batteries for electric and hybrid electric vehicles. e & i Elektrotechnik und Informationstechnik 2009, 126, (5), 186-193.[3] Furtmair, M.; Wolters, A.; Kühnel, F.; Thannhuber, M.; Sötz, V.; Sternad, M., The Impact of Fast-Charging on Cell Ageing of Industrial High-Power Lithium-Ion Batteries. In IMLB 2022, Sydney, Australia, 2022.[4] Aurbach, D.; Markovsky, B.; Rodkin, A.; Cojocaru, M.; Levi, E.; Kim, H.-J., An analysis of rechargeable lithium-ion batteries after prolonged cycling. Electrochimica Acta 2002, 47, (12), 1899-1911.[5] Uitz, M.; Sternad, M.; Breuer, S.; Täubert, C.; Traußnig, T.; Hennige, V.; Hanzu, I.; Wilkening, M., Aging of Tesla's 18650 Lithium-Ion Cells: Correlating Solid-Electrolyte-Interphase Evolution with Fading in Capacity and Power. Journal of The Electrochemical Society 2017, 164, (14), A3503-A3510.[6] Shutthanandan, V.; Nandasiri, M.; Zheng, J.; Engelhard, M. H.; Xu, W.; Thevuthasan, S.; Murugesan, V., Applications of XPS in the characterization of Battery materials. Journal of Electron Spectroscopy and Related Phenomena 2019, 231, 2-10.[7] Zhu, Y.; Pande, V.; Li, L.; Wen, B.; Pan, M. S.; Wang, D.; Ma, Z. F.; Viswanathan, V.; Chiang, Y. M., Design principles for self-forming interfaces enabling stable lithium-metal anodes. Proc Natl Acad Sci U S A 2020, 117, (44), 27195-27203.[8] Lagadec, M. F.; Ebner, M.; Zahn, R.; Wood, V., Communication—Technique for Visualization and Quantification of Lithium-Ion Battery Separator Microstructure. Journal of The Electrochemical Society 2016, 163, (6), A992-A994.[9] Zier, M.; Scheiba, F.; Oswald, S.; Thomas, J.; Goers, D.; Scherer, T.; Klose, M.; Ehrenberg, H.; Eckert, J., Lithium dendrite and solid electrolyte interphase investigation using OsO4. Journal of Power Sources 2014, 266, 198-207. Acknowledgment The authors wish to thank H. Schröttner (Institute of Electron Microscopy and Nanoanalysis, Graz University of Technology) for preferential access to preparation and examination equipment. Figure 1

Encapsulation of lutein in gelatin type A/B-chitosan systems via tunable chains and bonds from tweens: Thermal stability, rheologic property and food 2D/3D printability

Lutein could be stabilized in gelatin type A/B-chitosan systems by different polyoxyethylene sorbitan fatty acid esters (tweens) via tunable chains and bonds, and the homogeneous system held potential in food 2D/3D printing. During encapsulation of lutein in gelatin-chitosan matrix complexes, tween 40, tween 60 and tween 80 assisted in the excellent centrifugation stability, freeze–thaw stability, chemical stability as well as thermal stability. The tweens contained systems also possessed excellent rheological properties, including shearing thinning property, self-supporting characteristics, and favorable thixotropy. Especially, tween 80 performed well in facilitating the stability and rheological properties of systems with uniform micromorphology due to its long alkyl chains and carbon–carbon double bonds (two sp2 hybridized C-atoms) (from FTIR, XRD, SEM, etc.); and gelatin type B illustrated higher protection effects on lutein because of its strong electrostatic interaction with chitosan. The optimal systems could work as edible ink for 2D/3D printing on food with great UV-irradiation stability and high definition. Surimi could be modified by the optimal complex and possessed excellent shear-thinning property, proper yield stress, low dependence on frequency and stable structure, which was successfully applied for innovative 3D printing with sophisticated shapes. The practical food 2D/3D printing (like bread and surimi) demonstrated high potential in food creation and food innovation.

Reaction of 4-Bpin-o-Carborane with Ketones: Sequential Carbon Vertex Alkylation and B-B Bond Activation.

Diboron compounds are important reagents in a series of transition metal catalyzed or metal-free borylation reactions. We describe herein a unique reactivity of 4-Bpin-o-carborane with ketones under basic conditions, leading to sequential cage carbon alkylation, B-B bond activation and unexpected O-migration. The reaction was compatible with a good substrate scope including dialkyl or alkyl aryl ketones. The reaction mechanism is also proposed, involving cage CH deprotonation, nucleophilic attack of ketone, and O-migration along with B-B bond cleavage.

Synthesis of Carbamoyl Azides from Redox-Active Esters and TMSN3

AbstractAn efficient method for construction of C–N bonds is reported here. The iron-catalyzed azidation of N-hydroxy phthalimide (NHP) esters provides a convenient approach for the synthesis of carbamoyl azides with good substrate scope and functional group tolerance. Both aryl carbon C(sp2) and alkyl carbon C(sp3) sources can be used deliver the carbamoyl azides. Mechanistic studies were conducted and a two-stage process was identified.

Detection of acetone in the human breath as diabetes biomarker based on PPy/WO3 nanocomposite sensor by FFT continuous cyclic voltammetry method

AbstractThis research represents a novel detection method of acetone level in the exhaled breath samples (RH=88 %) based on polypyrrole/tungsten oxide (PPy/WO3) nanocomposite sensor. The PPy/WO3 sensor was fabricated by the deposition of nanocomposite on/between interdigitated electrodes (IDEs) through electrospray coating and was then characterized by FE‐SEM imaging. In this detection method, the coulometric signal of the sensor was calculated using Fast Fourier Continuous Cyclic Voltammetry (FFTCCV), where cyclic voltammetry (CV) was applied to the sensor in the defined potential rang and then charge changes of the sensor was obtained by integration of the current in all scanned potential ranges. FFTCCV method enhances the sensitivity of the sensor when exposed to the gas mixtures containing acetone. In addition to its fast coulometric response time (≤5 s) in the two linear ranges of 0.7–2.8 ppm and 2.8–28.2 ppm (R2=0.99), FFTCCV method provides the low detection limit of 70 ppb, and high sensitivity toward acetone at the optimum values of the parameters. The fabricated sensor showed great selectivity toward acetone when exposed to humid air and some exhaled gas like carbon dioxide, ammonia, methanol, ethanol and alkyl amines. The results were very satisfying as the sensor was capable to detect different acetone levels in human exhaled breath as non‐invasive diagnosis of diabetes with a good correlation (R2≃0.9) to the routine blood sugar test taken by different commercial glucometers results.

The effect of chemical functional groups on the octane sensitivity of fuel blends for spark-ignited and multimode engines

We report the octane sensitivity of fuel blends containing blendstocks of diverse chemical functionalities blended in concentrations up to 20% by volume into BOBs (Blendstocks for Oxygenate Blending). This study focuses on the blendstocks containing functional groups which lack reliable octane number data. The effects on octane sensitivity of blends of cyclopropanes, alkyl carbonates, oxiranes, alcohols, ketones, esters, nitrogen-containing compounds, cyclic and olefinic hydrocarbons, multifunctional materials containing combinations of these functionalities, and the co-blends of the blendstocks with ethanol in a BOB have been evaluated. Octane sensitivity of the blends containing functional groups that haven’t been evaluated before are discussed.

Alteration of Tecoma chip wood waste into microwave-irradiated activated carbon for amoxicillin removal: Optimization and batch studies

Amoxicillin (AMOX) in wastewater can promote antibiotic resistance in bacteria and affecting aquatic ecosystems, due to inadequate removal by conventional wastewater treatment plants. This study aimed to (i) optimizing Tecoma chip wood based activated carbon (TCAC) to adsorb amoxicillin (AMOX) using response surface methodology (RSM) and (ii) evaluating AMOX adsorption through batch and continuous modes. The RSM revealed the optimum conditions to be 657 W, 20 min and 0.99 g/g for radiation power, radiation time and impregnation ratio (IR), respectively. These optimum conditions resulted in AMOX removal efficiency of 88.07 mg/g and 27.68 % of TCAC’s yield. The BET surface area and total pore volume of TCAC were 924.85 m2/g and 0.3485 cm3/g respectively. The surface of TCAC was occupied with several functional groups namely primary amine, hydroxy, alkyl carbonate and terminal alkyne. These functional groups enhanced the adsorption process by forming hydrogen bond with AMOX molecules. The isotherm study revealed that AMOX-TCAC adsorption system obeyed the Langmuir model and the maximum monolayer adsorption capacity, Qm is 357.14 mg/g. Pseudo-second order (PSO) model fitted the best for the adsorption of AMOX by TCAC in the kinetic studies. Boyd plot divulged that the rate limiting step in the adsorption process was the film diffusion. Thermodynamic study confirmed the adsorption process to be endothermic, spontaneous and controlled by physisorption. In bed column studies, the percentage removal of adsorbates was found to increase when the adsorbates flowrate decreased, adsorbates initial concentration decreased, and bed height increased. For the breakthrough curve model, the adsorption is best fitted to Yoon Nelson model. TCAC demonstrated its efficacy in the removal of AMOX, proving successful in both batch mode and continuous mode operations. These findings suggest the potential for scaling up TCAC production for industrial purposes, indicating its suitability for larger-scale applications.

Reprocessing and shape recovery of polyurethane enabled by crosslinking with poly(β-cyclodextrin) via host-guest interactions

A 1,3-diol bearing an 18-carbon alkyl chain was synthesized via the esterification of stearyl alcohol with 2,2-bis(hydroxymethyl)propionic acid. This 1,3-diol was employed as the chain extender to synthesize a linear multi-segmented polyurethane (PU) carrying long alkyl side chains. It was found that the linear PU was readily crosslinked with poly(β-cyclodextrin) [viz. P(β-CD)], i.e., the supramolecular networks were obtained. The supramolecular crosslinking was generated via the inclusion complexation of P(β-CD) with the long alkyl chains of PU. The more the incorporation of P(β-CD), the higher the crosslinking densities. Compared to the linear PU, the PU-CD networks had the enhanced Yong's moduli and tensile strengths. Thanks to the supramolecular crosslinking, the PU-CD networks had the shape memory properties. It was found that the recovery of shape was quite dependent on the quantity of the inclusion complexation linkages. In addition, the PU-CD networks can be reprocessed (or recycled); the reprocessed PU-CD networks had the recovery of mechanical properties as high as 95%. The dynamic exchange of inclusion complexation is responsible for the reprocessing properties. Furthermore, the reprocessing behavior was successfully utilized to reprogram the original shapes of the shape memory networks.

The Effective Combination of Humic Acid Phosphate Fertilizer Regulating the Form Transformation of Phosphorus and the Chemical and Microbial Mechanism of Its Phosphorus Availability

In the process of phosphate fertilizer production, adding humic acid to produce humic-acid-value-added phosphate fertilizer can improve fertilizer efficiency and promote crop growth. Although studies have primarily focused on investigating the impact of humic acid’s structure and function on phosphorus availability in humic-acid-added phosphate fertilizers, there is limited research on the regulatory effects of phosphorus fertilizer structure and the synergistic mechanisms involving microorganisms. Therefore, this study aimed to examine the chemical and biological mechanisms underlying the increased efficiency of humic-acid-added phosphate fertilizers by implementing various treatment processes. These processes included physically blending humic acid with phosphate fertilizer (HA+P), chemically synthesizing humic acid phosphate fertilizer (HAP), using commercially available humic acid phosphate fertilizer (SHAP), employing ordinary potassium phosphate fertilizer (P), and implementing a control treatment with no phosphate fertilizer (CK). Investigating the synergistic mechanism of humic-acid-added phosphate fertilizers holds significant importance. The results showed that during the preparation of HAP at high temperature, a new absorption peak appeared at 1101 cm−1, and a new chemical bond -O- was formed. The hydroxyl fracture in humic acid combined with phosphoric acid to form a phosphate ester (P-O-C=O) structure. HAP residues were concentrated on the surface and loaded with more soil minerals. The content of highly active oxygen-containing functional groups—such as aromatic C-O, carboxyl/amide carbon and carbonyl carbon—increased significantly, while the content of alkyl carbon, oxyalkyl carbon, and aromatic carbon decreased. Upon combining humic acid with potassium phosphate, the carboxyl group and calcium ions formed the HA-m-P complex, increasing the content of soluble phosphate (H2PO4−) in the soil by 1.71%. Compared to HA+P treatment, HAP treatment significantly increased the soil’s available P content by 13.8–47.7% (P &lt; 0.05). The plant height, stem diameter, and above-ground biomass of HAP treatment were increased by 21.3%, 15.31%, and 61.02%, respectively, and the total accumulations of N, P, and K nutrient elements were increased by 6.71%, 31.13%, and 41.40%, respectively, compared to the control treatment. The results of high-throughput sequencing showed that the rhizosphere soil of HA+P and HAP treatment was rich in bacterial groups, the soil microbial structure was changed, and the bacterial community diversity was increased under HAP treatment. The number of genes encoding phytase and alkaline phosphatase associated with organophosphorus dissolution increased by 3.23% and 2.90%, respectively, in HAP treatment. Humic acid phosphate fertilizer forms phosphate esters in the process of chemical preparation. After application, the soil’s microbial community structure is changed, and soil enzyme activity related to phosphorus transformation is improved to promote tomatoes’ absorption of soil nutrients, thus promoting tomato plant growth and nutrient accumulation.

Spherical amino-functionalized covalent organic frameworks: Synthesis and adsorption performance toward perfluorinated compounds

Perfluorinated compounds (PFCs) are widely used in textiles, fire protection, metal electroplating, and semiconductor production owing to their hydrophobic and oil-repellent characteristics. However, they are also persistent organic pollutants. The uncontrolled discharge of PFCs into the environment has led to serious global pollution. PFCs pose severe reproductive, neural, immune, and other threats to human health by accumulating through the food chain. Thus, the development and application of high-performance extraction materials has become a research hotspot in efforts to achieve the accurate detection of trace PFCs in environmental waters. Most traditional PFC adsorbents present a number of disadvantages, such as low adsorption selectivity, slow diffusion, and poor reusability. Covalent organic frameworks (COFs) are crystalline polymers with ordered porous structures, large specific surface areas, and high chemical and thermal stability. These frameworks can easily be functionalized for the desired purpose. In this paper, spherical amino-functionalized COFs (denoted COF-NH2) were fabricated via a two-step method to effectively enrich/remove PFCs from water. First, vinyl covalent organic framework (Vinyl COF) was synthesized at room temperature using 1,4-diradical-2,5-divinylbenzene (Dva) and 1,3,5-tris(4-aminophenyl)benzene (Tab) as building blocks. Then, thioether-bridged aromatic amine-functionalized spherical COF-NH2 was synthesized through a thiol-alkenyl click reaction using 4-aminothiophenol as the functional monomer. COF-NH2 showed good dispersion in water owing to its abundant amino groups, forming multiple hydrogen bonds with the F atoms of PFCs. The synergistic hydrophobic interactions between the organic skeleton of the COF and alkyl carbon chains of the PFCs led to enhanced adsorption efficiency. The produced Vinyl COF and COF-NH2 were characterized by Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and Brunner-Emmet-Teller (BET) measurements. The results confirmed that spherical COF-NH2 materials with a homogeneous size distribution were successfully fabricated. The obtained COF-NH2 microspheres had a diameter of approximately 500 nm and exhibited high thermal stability as well as a large specific surface area and pore volume. The adsorption kinetics, isotherm adsorption models, pH effects, and regeneration properties of COF-NH2 were also investigated, and the results indicated that the adsorption of PFCs by COF-NH2 conformed to the pseudo-second-order kinetic and Langmuir isotherm adsorption models. The obtained COF-NH2 microspheres can be applied over a wide pH range, and the best adsorption effect was achieved in neutral and alkaline environments. After five cycles of regeneration and reuse, the COF-NH2 microspheres retained their good adsorption efficiency for PFCs. The adsorption mechanism was mainly attributed to the synergistic effect of hydrogen bonding and hydrophobic interactions between COF-NH2 and the PFCs. The extraction efficiencies of the microspheres toward five PFCs (perfluorobutyric acid, perfluorovaleric acid, perfluorohexanoic acid, perfluorooctanoic acid, and perfluorononanoic acid) in tap and Pearl River water samples were between 91.76% and 98.59%, with relative standard deviations (RSDs) (n=3) varying from 0.82% to 3.8%; these findings indicate that the obtained COF-NH2 is promising for the extraction of PFCs from complex water samples. Given their uniform size distribution, high thermal stability, good adsorption performance, and reusability, the novel spherical COF-NH2 materials developed in this study may be used as solid-phase extraction materials or filled into liquid chromatographic columns for the enrichment, separation, and detection of PFCs in complex samples.

Homogeneous polyurethane foaming systems containing polyester diol, ethylene glycol, and alkylated polyethylenimine‐CO2 adducts

AbstractCO2 adducts from alkylated polyethylenimines (PEIs) in powder form are newly developed blowing agents for polyurethanes (PUs) to replace the ozone‐depleting and/or global warming halogen‐containing blowing agents. However, they are difficult to disperse into the raw materials of PUs. Herein, we explored reactive solvents for alkyl‐grafted PEI‐based CO2 adducts (xCn‐PEI‐CO2s, whose alkyl carbon number n = 4, 8, or 12 and grafting rate x = 5%, 10%, or 15%) and found that the most effective solvent was ethylene glycol (EG), with solute mass concentrations exceeding 50%. According to this, we designed homogenous foaming systems for PUs, containing poly(ethylene‐co‐diethylene glycol adipate)diol, EG, and different xCn‐PEI‐CO2 blowing agents, with mass percentages of 85, 11.25, and 3.75, respectively. The xCn‐PEI‐CO2 blowing agents in the ternary mixture could effectively blow PUs, with densities ranging from 210 to 240 kg/m3. The addition of 0.1 g of water as an extra blowing agent reduced the densities down to 110 kg/m3, compared with the 140 kg/m3 density of the control foam blown solely by water. The liquid status of the ternary foaming mixtures and their cooperative performance with water to blow PUs could enhance the suitability of the climate‐friendly xCn‐PEI‐CO2 blowing agents in PU foam industry.

Green nano multicationic ionic liquid based surfactants for enhanced oil recovery: A comparative study on design and applications

This contribution explores utilizing the novel nanostructure multicationic surface active ionic liquids (MSAILs) as alternatives to conventional surfactants in enhanced oil recovery (EOR). A new MSAIL consisting of three benzimidazole rings and four carbon alkyl chains attached by triazine spacer, namely [(C4benzim)3TA][Cl3], was economically synthesized with a two steps method. Characterization was performed via FT-IR, NMR, XRD, TGA, DTG, SEM, and DLS analysis. The effects of the product on interfacial tension (IFT), micellization, emulsification, and wettability alteration of the crude oil–water system were experimented. The IFT decreased up to 85.9% at critical micelle concentration (CMC) of 8 × 10−3 molˑdm−3. Rising temperature, from 298.2 to 323.2 K, significatly improves the capability of the product in IFT reduction up to 34.9%. Stable emulsion formation of crude oil–aqueous solutions reached to 84.2 and 80.6%after one day and one week, respectively. Furthermore, surface wettability was transferred from oil-wet to water-wet. Compared to other three structurally homologous imidazolium and benzimidazolium MSAILs, the greater effect of [(C4benzim)3TA][Cl3] was revealed at lower concentrations that was attributed to the strong hydrophobic aromaticrings in the structure. The Frumkin adsorption isotherm exactly reproduced the IFT data, and accordingly, the adsorption and thermodynamic parameters were determined.

Poly (ionic liquid)s-silica spheres as effective core-shell catalysts for the conversion of glucose and fructose into 5-hydroxymethylfurfural

5-Hydroxymethylfurfural (5-HMF), as a significant, bio-derived platform chemical molecule, has been under extensive research due to its wide application in petrochemical industry. In this work, three kinds of poly (ionic liquid)s-silica spheres (PIL@SiO2) with various lengths of alkyl chains as effective core-shell catalysts were prepared by the polymerization and coating methods, and were used to prepare 5-HMF from glucose and fructose with optimal results. When the alkyl carbon number of PIL monomer was 18, PIL@SiO2-18 displayed good catalytic activity in 5-HMF production, resulting in the highest yields of 77.36% and 72.8% from glucose and fructose in methyl isobutyl ketone (MIBK)/ saturated solution of sodium chloride (Sat.NaCl) biphasic solvent. A possible reaction mechanism was proposed that the core-shell synergistic catalysis effectively promoted the preparation of 5-HMF from monosaccharide, in which Lewis acidic polycationic centers contributed to driving the isomerization process. The promising approach provides an efficient strategy for silica-based core-shell synergistic catalysts in the synthesis of 5-HMF from carbohydrates.