Modification Of Functional Groups Research Articles

A Review on Advancements in Polysulfone-Based Membranes for Gas Separation Applications

Gas separation has changed over the last few decades with membrane technology emerging as an important player. Polysulfone is considered an interesting material for gas separation membrane applications mainly due to its good thermal and chemical stability and excellent mechanical strength at a low cost. This review presents a comprehensive discussion on the advancements acheived in the development of polysulfone-based membranes for gas separation. It focuses on various strategies that have been reported to enhance the performance of these membrane materials, including filler incorporation, polymer blending and the addition or chemical modification of functional groups that confer specific adaptability to the polymers.

Engineering surface functional groups of 2D organic metal chalcogenides to regulate lubrication performance across scales

Two-dimensional (2D) layered materials are widely used to enhance lubrication performance in various conditions due to their low friction and sliding interfaces. However, the uncontrolled modification and dispersion of functional groups on 2D materials limit their lubrication performance and ultra-low friction capabilities at different scales. Herein, we developed three Pb-based organic metal chalcogenides nanosheets, Pb(SPh-NH2/-COOH/-OH), with long-range ordered functional groups on the [PbS2] layer, to reduce friction and wear across scales. We organically modified these nanosheets prior to exfoliation, achieving micro-lateral and nano-vertical size. As ethanol additives, these nanosheets reduced the coefficient of friction (COF) and wear volume by over 44.8 % and 78.9 %, respectively. Dry tests demonstrated the Pb(SPh-OH) coating on SiO2/Si substrate reduced the COF from 0.65 to 0.07. Compared to SiO2/Si substrate, lateral force microscopy revealed friction reducing up to 57.5 %, 85.5 %, and 90.9 % for Pb(SPh-NH2/-COOH/-OH), respectively. These novel 2D materials provide a heuristic strategy for lubrication, suitable for anti-friction applications under different conditions across scales.

Highly efficient iodine capture from vapor and water using UiO-66-X: Effects of functional group modifications

Radioactive iodine waste from the nuclear industry poses a critical threat to human health, and its effective capture has become an important research topic. In this study, modified UiO-66-X adsorbents (where X is ATA, BTA, or STA) were used to investigate the effects of the free functional groups in the UiO-66 skeleton on iodine capture in the vapor and solution states. The adsorption behavior revealed that the capture efficiency of UiO-66-ATA was substantially higher than that of UiO-66-BTA and UiO-66-STA because the electron-donating amino groups could enhance the I − I···π halogen bond interactions compared with the electron-withdrawing carboxyl and sulfonic acid groups. In addition, the pore volume of UiO-66-ATA was significantly higher than those of UiO-66-BTA and UiO-66-STA. In particular, the removal uptakes of UiO-66-ATA were 1108.1 mg/g (vapor phase) and 3601.9 mg/g (aqueous solution). This study is the first to investigate the effects of functional groups on the adsorption uptake of UiO-66 toward iodine. This efficient functional group modification strategy holds significant promise for the development of novel metal–organic framework adsorbents.

Preparation of high-efficient donor-π-acceptor system with crystalline g-C3N4 as charge transfer module for enhanced photocatalytic hydrogen evolution

Donor-π-acceptor (D-π-A) type photocatalysts with g-C3N4 as π-module have attracted much attention due to their optimized conjugate structure and enhanced electron directed driving. However, the inefficient charges migration of g-C3N4 due to its amorphous or semi-crystalline structure and limitation of available functional groups are present challenges. In this work, the D-π-A type high crystalline carbon nitride (HCCN) has been obtained by in-situ introducing amide and cyanide groups into the high-crystallinity melon framework. The synergistic effect of functional group modification and crystallinity regulation greatly enhances the electron induction driving and charge carrier density. Moreover, the density functional theory calculations demonstrate that the D-π-A structure could induce the local charge distribution of melon units to provide a unique and stable pathway for photoinduced charges migration. The as-prepared HCCN sample shows a superior visible-light photocatalytic performance for hydrogen evolution with an apparent quantum efficiency (AQE) of 12.2 ​% at 420 ​± ​15 ​nm, which is 23.7 times higher than that of original g-C3N4. Finally, the charge separation and transfer processes as well as the possible photocatalytic reaction mechanisms of HCCN sample are also investigated.

Total Synthesis Analysis of Pseuboyenes D

In this work, we propose a total synthesis route for the antifungal agent Pseuboyenes D, a compound derived from Pseudallescheria boydii CS-793. Pseuboyenes D exhibits antifungal activity comparable to Amphotericin B while offering the advantage of a simpler structure, making it a promising candidate for clinical applications. The system became the focus of this analysis due to its regioselectivity, and after exploration, a [2+2] photocycloaddition and ring expansion strategy was adopted to construct the key bridged ring system. The route employs readily available substrates and mild reaction conditions, making it scalable and suitable for large-scale production. Computational analysis of the regioselectivity of the photocycloaddition revealed that the bridged adduct was thermodynamically favored over the fused system. The synthetic route was further diversified by incorporating functional group modifications using TMS derivatives, enhancing the potential for pharmacological applications. Overall, this work establishes an efficient and scalable synthetic pathway for Pseuboyenes D, paving the way for future applications in antifungal drug development.

Methods for Introdusing Fluorescent Labels into Polysaccharides

Polysaccharides are widely represented in plants and bacteria, where they are distinguished by their extraordinary structural diversity and the performance of various functions. To study the functions of polysaccharides, their fluorescent labeling is needed. This review discusses methods for introducing fluorescent labels into polysaccharides by chemical modification of certain functional groups of these complex biopolymers, as well as using the so-called bioorthogonal reactions, which allow labeling in a cell without affecting its viability. In addition to modification with organic dyes, the possibility of using quantum dots and coordination compounds of lanthanides is also discussed.

Fluorescent cellulose hydrogels based on corn stalk of double sulfhydryl functional group modification for Hg(II) removal and detection

Ions of mercury, one of the most hazardous heavy metals in nature, pose serious risks to the environment and human health. Blue sulfur-doped carbon dots (SCDs) from corn stalks were utilized as material. The SCDs were incorporated into a carboxylated hydrogel modified with sulfur, and a compound gel (SCDs–KTOCS gel) was successfully fabricated for simultaneous fluorescence detection and Hg(II) adsorption. This enabled the effective identification and removal of Hg(II) from contaminated water. The chemical content, fluorescence properties, and adsorption behaviors of the SCDs–KTOCS–gels were analyzed. The results demonstrate that the SCDs–KTOCS–gels exhibited effective Hg(II) adsorption (193 mg/g) and an extensive linear spectrum for Hg(II) fluorescence emission (150–500 mg/L; detection limit = 1.5668 mg/L). The adsorption values fit well with the Temkin models and pseudo-second-order kinetics. Additionally, Hg(II) detection and adsorption in the SCDs–KTOCS–gels were examined. By exchanging the existing probe for a suitable one that fits various relevant applications, this study suggests an environmentally friendly and sustainable method of producing materials for removing and detecting Hg(II) and constructing a fluorescence hydrogel for the detection and adsorption of different metals.

Exploring Pyrazine-Based Organic Redox Couples for Enhanced Thermoelectric Performance in Wearable Energy Harvesters.

Thermoelectric generators (TEGs) based on thermogalvanic cells can convert low-temperature waste heat into electricity. Organic redox couples are well-suited for wearable devices due to their nontoxicity and the potential to enhance the ionic Seebeck coefficient through functional-group modifications. Pyrazine-based organic redox couples with different functional groups is comparatively analyzed through cyclic voltammetry under varying temperatures.The results reveal substantial differences in entropy changes with temperature and highlight 2,5-pyrazinedicarboxylic acid dihydrate (PDCA) as the optimal candidate.How the functional groups of the pyrazine compounds impact the ionic Seebeck coefficient is examined, by calculating the electrostatic potential based on density functional theory.To evaluate the thermoelectric properties, PDCA is integrated in different concentrations into a double-network hydrogel comprising poly(vinyl alcohol) and polyacrylamide. The resulting champion device exhibits an impressive ionic Seebeck coefficient (Si) of 2.99mV K-1, with ionic and thermal conductivities of ≈67.6 µS cm-1 and ≈0.49W m-1 K-1, respectively.Finally, a TEG is constructed by connecting 36 pieces of 20× 10-3 m PDCA-soaked hydrogel in series. It achieves a maximum power output of ≈0.28 µW under a temperature gradient of 28.3 °C and can power a small light-emitting diode. These findings highlight the significant potential of TEGs for wearable devices.

Synergistic Tri‐efficiency Enhancement Utilizing Functionalized Covalent Organic Frameworks for Photocatalytic H2O2 Production

AbstractThe overall maximization of photocatalytic H2O2 production efficiency urgently requires the comprehensive optimization of each step in multiplex photocatalysis. Despite numerous endeavors, isolated researches focusing on single efficiencies hinder further advancements in overall catalytic activity. In this work, a series of imine‐linked COFs (TT‐COF‐X), incorporating electronically tunable functional groups (X = ─H, ─OMe, ─OH, ─Br), are rationally fabricated for visible‐light‐driven H2O2 production via a dual‐channel pathway involving 2e− water oxidation and 2e− oxygen reduction. Combined simulations and characterizations reveal that the synergistic modification of functional groups for electronic conjugation and locally intramolecular polarity collectively enhanced light absorption, charge separation and transfer, and interface water–oxygen affinity efficiency. Notably, femtosecond time‐resolved transient absorption (fs‐TA) reveals that the polarity‐induced built‐in electric field play a crucial role in facilitating exciton dissociation by reacting BIEF‐mediated shallow trapping state. The simultaneously optimal tri‐efficiency ultimately results in the highest H2O2 production rate of 3406.25 µmol h−1 g−1 and apparent quantum yields of 8.1% of TT‐COF‐OH. This study offers an emerging strategy to rational design of photocatalysts from the comprehensive tri‐efficiency‐oriented perspective.

High-performance removal of methylene blue dye using porous lignin extracted from sugarcane bagasse by deep eutectic solvent

This study evaluated the ability of triethyl benzyl ammonium chloride/lactic acid deep eutectic solvent extracted lignin (TEBAC/LA-DES-L) to adsorb methylene blue (MB) without additional functional group modification. The structure and morphology of TEBAC/LA-DES-L were characterized using SEM, BET, FT-IR, and TGA techniques. Various factors influencing MB adsorption, such as extraction temperature, solution pH, adsorbent dose, initial MB concentration, adsorption time, and reaction temperature, were investigated. The Redlich-Peterson isotherm displayed a good fit for the experimental data, with a maximum adsorption capacity of 85.16 mg/g. Kinetic analysis suggested that the adsorption process followed the pseudo-second-order model, with adsorption occurring in <100 min on DES-L-4 h. The mechanism of MB adsorption on DES-L-4 h was attributed to electrostatic attraction, hydrophobic interactions, and hydrogen bonding forces. Overall, DES-L-4 h demonstrated high adsorption capacity and rapid adsorption rate, making it a promising adsorbent for effectively removing cationic dyes from wastewater.

Effective strategies alleviate mitochondrial toxicity of perfluorooctanoic acid: Modification of functional head group and inhibition of toxic target

Minimizing the detrimental impacts of perfluorooctanoic acid (PFOA) on human health is a daunting task. Here, we aimed to propose effective strategies for reducing PFOA-induced mitochondrial toxicity in human liver and intestinal cells. PFOA could occupy the fatty acid-binding pockets of human peroxisome proliferator-activated receptor alpha (hPPARα). PFOA not only could structurally interact with hPPARα, but also substantially upregulated the expression levels of PPARα and its downstream gene (i.e., pyruvate dehydrogenase kinase (PDK4)). The increased expression of PDK4 was associated with the mitochondrial toxicity of PFOA, and inhibition of PDK4 or knock-down of PDK4 could effectively attenuate the mitochondrial toxicity of PFOA. Moreover, modification of carboxyl group via an esterification of PFOA into methyl perfluorooctanoate (MePFOA) decreased the affinity to hPPARα, resulting in the loss of upregulated expressions of PPARα and PDK4. Lower mitochondrial toxicity and cytotoxicity were found in the MePFOA-treated cells compared to PFOA exposure. Our study supported that the carboxyl group of PFOA (as functional head group) was required for inducing its mitochondrial toxicity. Two strategies, including modification of functional head group and inhibition of toxic target of PFOA, are feasible to ameliorate mitochondrial toxicity of PFOA.

A Novel Composite Material UiO-66-Br@MBC for Mercury Removal from Flue Gas: Preparation and Mechanism.

To reduce the mercury content in flue gas from coal-fired power plants and to obtain high-performance, low-cost mercury adsorbents, a novel composite material was prepared by structural design through the in situ growth method. Functionalization treatments such as the modification of functional groups and multilayer loading of polymetallic were conducted. These materials include the MOF material UiO-66 and modified biochar doped with Fe/Ce polymetallic, both of which contain unsaturated metal centrals and oxygen-containing functional groups. On the basis of obtaining the effects of adsorption temperature and composite ratio on the Hg0 removal characteristics, coupling and synergistic mechanisms between the various types of active centers included were investigated by using a variety of characterization and analysis tools. The active adsorption sites and oxidation sites were identified during this process, and the constitutive relationship between the physicochemical properties and the performance of Hg0 removal was established. The temperature-programmed desorption technique, Grand Canonical Monte Carlo simulation, and adsorption kinetic model were employed to reveal the mechanism of Hg0 removal. The results showed that the UiO-66-Br@MBC composite adsorbent possessed an excellent Hg0 removal performance at adsorption temperatures ranging from 50 to 250 °C, and targeted construction of adsorption and oxidation sites while maintaining thermal stability. The Hg0 removal by the composites is the result of both adsorption and oxidation. The micropores and small pore mesopores in the samples provide physical adsorption sites. The modified biochar acts as a carrier to facilitate the full exposure of the central metal zirconium ions, the formation of more active sites, and the process of electron transfer. The doping modification of the Br element can enhance the overall redox ability of the sample, and the introduced Fe and Ce polymetallic ions can work in concert to promote the oxidation process of Hg0. The excellent regulation of the ratio between adsorption and oxidation sites on the surface of the composite material finally led to a significant boost in the samples' capacity to remove Hg0.

Green synthesis of zinc oxide nanoparticles for the removal of phenol from textile wastewater

This study investigated the use of zinc oxide nanoparticles (ZnO NPs) as an adsorbent for removing total phenols from textile wastewater. The ZnO NPs were synthesized by reducing Zn(NO3)2⋅6H2O using an extract from Neem leaves (Azadirachta indica). Characterization of the adsorbent was performed using Fourier Transform Infrared (FTIR) spectroscopy to identify functional group modifications, high-resolution scanning electron microscopy (HRSEM) for structural orientation, energy dispersive spectroscopy (EDS) for elemental analysis, and X-Ray diffraction analysis (XRD) for crystallinity, revealing particle crystallinity around 200 nm. Adsorption experiments were conducted over contact times of 20–60 min, with adsorbent loadings between 0.2 and 1 g/100 mL, and temperatures ranging from 30 to 50 °C. Optimal phenol removal, achieving 55.93% (0.67 mg/L), occurred at 43.40 min, 33.70 °C, and an adsorbent dosage of 0.69 g/L of textile wastewater. The phenol adsorption process using ZnO NPs was exothermic, spontaneous, and required low energy, fitting well with the Langmuir isotherm and following a pseudo-second-order kinetic model.

Chemical Methods for the Construction of Spirocyclic β-Lactams and Their Biological Importance

AbstractSpirocyclic β-lactams are a family of natural and synthetic chemicals with different biological activities, including antibacterial properties, and interact with critical physiological targets such as T-type calcium channels and acetyl-CoA cholesterol acyltransferase. Their unique chemical structure, combining a spiro ring system with a β-lactam group, offers promising opportunities for the targeted discovery of medications in medicinal chemistry. Spirocyclic β-lactams have the potential to be adaptable frameworks for developing novel therapeutic medicines with particular three-dimensional pharmacophoric characteristics and increased biological efficacy. Numerous methods are employed for the synthesis of spirocyclic β-lactams, such as cyclization, functional group modifications, asymmetric synthesis utilizing chiral catalysts and biomimetic approaches. In this short review, two distinct approaches describing recent syntheses of spirocyclic β-lactams (from 2021 to 2024) are discussed. The first is based on constructing the β-lactam ring, while the other entails transforming monocyclic β-lactams into spirocyclic structures. These methods include detailed reaction processes and descriptions of the biological functions of the target spirocycles. The applications of spirocyclic β-lactams in medicinal chemistry highlight their role in the synthesis of structurally diverse compounds with significant therapeutic potential, demonstrating creative chemical methods for building complex molecular structures.1 Introduction2 β-Lactam Ring Synthesis3 Non-β-Lactam Ring Synthesis4 Miscellaneous Examples5 Conclusion and Outlook

Fabrication of Mupirocin-Loaded PEGylated Chitosan Nanoparticulate Films for Enhanced Wound Healing.

Chitosan-based biomaterials are being investigated for their unique properties that support skin regeneration and wound healing. This study focused on the preparation and characterization of a mupirocin (Mup)-loaded PEGylated chitosan (CS-PEG) nanoparticulate film (NF) [CBNF]. The CBNF was characterized using FTIR spectroscopy and SEM analysis. The results demonstrated that CBNF was successfully incorporated into the composites, as shown by functional group modification through FTIR analysis. Additionally, the SEM micrograph revealed the deposition of nanoparticles (<200 nm) on the surface of transparent CBNF. The film has higher water absorption (≥1700%) and moderate water retention ability within 6 h. Furthermore, histological findings showed significant development, with re-epithelialization and granulation of tissues after 19 days, indicating the healing efficiency of CNBF. These results suggest that drug-loaded films could be an effective carrier and delivery agent for Mup-like anti-inflammatory drugs.

Boosting photocatalytic performance of polymeric carbon nitride by adjusting its donor-acceptor structure via functional group modification strategy

Solar-driven photodegradation of pollutant is attractive for environmental remediation. Herein, we designed and synthetized a new kind of group-modified polymeric carbon nitride (PCN) photocatalyst with urea and 4-Nitro-o-phenylenediamine by one-pot method and applied to degrade bisphenol A (BPA) in aqueous solution. The light response range of photocatalyst had been extended a lot due to conjugation and electron-withdrawing properties of nitrobenzene. Physical analysis shows that 4-Nitro-o-phenylenediamine grafting brings an improved charge separation capacity. EPR and DFT results demonstrate the charge separation is significantly affected by the donor-acceptor structure of PCN, which can be altered via aromatic electron-withdrawing group. The kinetic constant of photocatalytic degradation for BPA was promoted by 8.8-times greater than unmodified PCN and a good recyclability was achieved. To verify the universality of group modification strategies, we prepared other two kinds of photocatalysts via electron-withdrawing group modification strategy and their photocatalytic performance all had been improved obviously.

Polystyrene nanoplastics induced learning and memory impairments in mice by damaging the glymphatic system

The excessive usage of nanoplastics (NPs) has posed a serious threat to the ecological environment and human health, which can enter the brain and then result in neurotoxicity. However, research on the neurotoxic effects of NPs based on different exposure routes and modifications of functional groups is lacking. In this study, the neurotoxicity induced by NPs was studied using polystyrene nanoplastics (PS-NPs) of different modifications (PS, PS-COOH, and PS-NH2). It was found that PS-NH2 through intranasal administration (INA) exposure route exhibited the greatest accumulation in the mice brain after exposure for 7 days. After the mice were exposed to PS-NH2 by INA means for 28 days, the exploratory ability and spatial learning ability were obviously damaged in a dose-dependent manner. Further analysis indicated that these damages induced by PS-NH2 were closely related to the decreased ability of glymphatic system to clear β-amyloid (Aβ) and phosphorylated Tau (P-Tau) proteins, which was ascribed to the loss of aquaporin-4 (AQP4) polarization in the astrocytic endfeet. Moreover, the loss of AQP4 polarization might be regulated by the NF-κB pathway. Our current study establishes the connection between the neurotoxicity induced by PS-NPs and the glymphatic system dysfunction for the first time, which will contribute to future research on the neurotoxicity of NPs.

Boosting the Activation of Molecular Oxygen and the Degradation of Rhodamine B in Polar-Functional-Group-Modified g-C3N4.

Molecular oxygen activation often suffers from high energy consumption and low efficiency. Developing eco-friendly and effective photocatalysts remains a key challenge for advancing green molecular oxygen activation. Herein, graphitic carbon nitride (g-C3N4) with abundant hydroxyl groups (HCN) was synthesized to investigate the relationship between these polar groups and molecular oxygen activation. The advantage of the hydroxyl group modification of g-C3N4 included narrower interlayer distances, a larger specific surface area and improved hydrophilicity. Various photoelectronic measurements revealed that the introduced hydroxyl groups reduced the charge transfer resistance of HCN, resulting in accelerated charge separation and migration kinetics. Therefore, the optimal HCN-90 showed the highest activity for Rhodamine B photodegradation with a reaction time of 30 min and an apparent rate constant of 0.125 min-1, surpassing most other g-C3N4 composites. This enhanced activity was attributed to the adjusted band structure achieved through polar functional group modification. The modification of polar functional groups could alter the energy band structure of photocatalysts, narrow band gap, enhance visible-light absorption, and improve photogenerated carrier separation efficiency. This work highlights the significant potential of polar functional groups in tuning the structure of g-C3N4 to enhance efficient molecular oxygen activation.

Linkage Conversion in Covalent Organic Frameworks: An Efficient Strategy to Promote Photocatalytic Organic Transformations

AbstractCovalent organic frameworks (COFs) are emerging as promising heterogeneous photocatalysts for organic transformations, owing to their fascinating optical properties, excellent recyclability, and customizable chemical structures. To maximize the photocatalytic activity of COFs, various strategies have been explored, including metal complexation, construction of donor‐acceptor structures, modification of functional groups, hybridization with inorganic semiconductors, and linkage conversion. Among these, linkage conversion has proved to be particularly effective, driving the production of numerous value‐added organic chemicals. In this concept article, we present a comprehensive overview of the latest advancements in linkage conversion and highlight the most enlightening examples that have adopted such a strategy to boost the photocatalytic capabilities of COFs for organic transformations. It is anticipated that this concept will assist researchers in designing novel COFs with multifunctional linkages, paving the way towards their broader application in organic synthesis.

Intramolecular Quaternary Carbon Nitride Homojunction for Enhanced Visible Light Hydrogen Production.

In this work, an intramolecular carbon nitride (CN)-based quaternary homojunction functionalized with pyridine rings is prepared via an in situ alkali-assisted copolymerization strategy of bulk CN and 2-aminopyridine for efficient visible light hydrogen generation. In the obtained structure, triazine-based CN (TCN), heptazine-based CN (HCN), pyridine unit incorporated TCN, and pyridine ring inserted HCN constitute a special multicomponent system and form a built-in electric field between the crystalline semiconductors by the arrangement of energy band levels. The electron-withdrawing function of the conjugated heterocycle can trigger the skeleton delocalization and edge induction effect. Highly accelerated photoelectron-hole transfer rates via multi-stepwise charge migration pathways are achieved by the synergistic effect of the functional group modification and molecular quaternary homojunction. Under the addition of 5mg 2-aminopyridine, the resulting homojunction framework exhibits a significantly improved hydrogen evolution rate of 6.64mmol g-1 h-1 with an apparent quantum efficiency of 12.27% at 420nm. Further, the catalyst verifies its potential commercial value since it can produce hydrogen from various real water environments. This study provides a reliable way for the rational design and fabrication of intramolecular multi-homojunction to obtain high-efficient photocatalytic reactions.