Introduction Of Functional Groups Research Articles

The Influence of Carbon Nanotube Functionalization on Water Contaminated by Diesel and Benzoic Acid: A Comparison of Two Case Studies

This article simply aims to compare two case studies concerning the purification, using carbon nanotubes, of water contaminated by the following two different common pollutants: benzoic acid and diesel. In particular, the aim is to highlight how the different natures of both of the polluting molecules and the carbon nanotubes play a fundamental role in water treatment. These two pollutants were taken into consideration because of their different chemical natures: benzoic acid is a polar pollutant, while the molecules present in diesel are substantially nonpolar. The carbon nanotubes used were both functionalized and nonfunctionalized. Functionalization is a process that allows for the introduction of functional groups onto the surface of carbon nanotubes. In this research, carboxylic functionalization was performed, which allowed for the insertion of carboxylic groups through attacks with sulfuric and nitric acids. Thanks to the results obtained, it was possible to quantify the optimization of the purification process depending on the types of carbon nanotubes and polluting molecules considered. The functionalized nanotubes exhibited greater performances in the treatment of water contaminated by benzoic acid compared to the nonfunctionalized ones. Instead, in the treatment of water contaminated by diesel, a greater purification capacity was shown by the nonfunctionalized carbon nanotubes compared to the functionalized ones.

Graphene oxide synthesis from coconut fiber powder using triple superphosphate catalyst and its potency for secondary battery electrode

Coconut fiber, considered an organic waste, emerges as a promising alternative carbon source for graphene oxide production—a material characterized by its conductive nature due to oxidation and the introduction of functional groups. The synthesis process involves carbonization with varied holding times (10, 20, and 30 minutes) and the utilization of Triple Superphosphate (TSP) and Ferrocene catalysts at concentrations of 10 wt.% and 20 wt.%. Subsequently, the sonication method is employed to enhance the electrical conductivity of graphene oxide post-carbonization. Notably, the electrical conductivity tests, conducted using a sourcemeter, revealed the optimum performance at 20 minutes of carbonization duration and a 20 wt.% TSP catalyst concentration, yielding an impressive electrical conductivity of 11,489.86 S/m. These findings underscore the significance of tailored parameters in optimizing graphene oxide synthesis for applications such as high-conductivity battery anodes.

The modified pomegranate peel as an economical and highly effective adsorbent for malachite green dye removal from wastewater

This research investigated the ability of acid-modified pomegranate peel to remove malachite green (MG) dye from aqueous solutions. Pomegranate peel, an abundant agricultural byproduct, was modified using hydrochloric acid to enhance its adsorption capacity. The effects of parameters like particle size, pH, initial MG concentration, contact time, temperature and adsorbent dosage on the dye removal efficiency were studied. Under optimized conditions of pH 8, 40 min contact time, 25°C temperature and 0.01 g/ml adsorbent dose with 5 mg/L MG solution, about 96.8 % dye removal was achieved. Kinetic data fitted well to the pseudo-second order model, indicating chemisorption with electrostatic interactions governing the adsorption. Equilibrium data were best described by the Temkin isotherm model, suggesting a heterogeneous binding energy distribution. Thermodynamic calculations revealed the exothermic and spontaneous nature of MG adsorption. FTIR analysis confirmed introduction of functional groups like carboxyl, amine and alkyl groups on the adsorbent surface after acid modification, enabling interactions with dye cations. SEM images displayed increased surface roughness and porosity for the modified biosorbent relative to the raw form. The acid-modified pomegranate peel proved to be an economical, eco-friendly and effective adsorbent for removing the hazardous cationic dye MG from wastewater. The findings support agricultural waste valorization for environmental remediation applications.

Mechanisms for synergistically enhancing cadmium remediation performance of biochar: Silicon activation and functional group effects

This work proposes an advanced biochar material (β-CD@SiBC) for controllable transformation of specific silicon (Si) forms through endogenous Si activation and functional group introduction for efficient cadmium (Cd) immobilization and removal. The maximum adsorption capacity of β-CD@SiBC for Cd(II) reached 137.6 mg g−1 with a remarkable removal efficiency of 99 % for 200 mg L−1Cd(II). Moreover, the developed β-CD@SiBC flow column exhibited excellent performance at the environmental Cd concentration, with the final concentration meeting the environmental standard for surface water quality (0.05 mg L−1). The remediation mechanism of β-CD@SiBC could be mainly attributed to mineral precipitation and ion exchange, which accounted for 42 % and 29 % of the remediation effect, respectively, while functional group introduction enhanced its binding stability with Cd. Overall, this work proposes the role and principle of transformation of Si forms within biochar, providing new strategies for better utilizing endogenous components in biomass.

Optimizing the electromagnetic wave absorption properties of core-shell Fe/FeN/Fe3C@GN nanoparticles by low-temperature NH3 plasma

Surface modification via low-temperature plasma has an extensive application prospect in different engineering fields due to its comprehensive merits in facilitating the introduction of functional groups and creating more heterogeneous interfaces. Herein, a simple high-temperature plasma method is developed to get novel multiple-phase nanocomposites of core-shell Fe/FeN/Fe3C@GN nanoparticles with bifunctional characteristics of microwave absorption (MA) and anti-corrosion. And then, we further investigate the MA properties of Fe/FeN/Fe3C@GN nanoparticles after low-temperature NH3 plasma etching. It is found that surface modification of Fe/FeN/Fe3C@GN nanoparticles can generate remarkable changes in specific surface areas, Raman features and MA properties of these nanocomposites. The Fe/FeN/Fe3C@GN nanoparticles after NH3 plasma etching possess excellent MA properties with an optimal reflection loss (RL) of −51.0 dB at an ultra-thin thickness of 1.9 mm with a low filling content of 30 wt% and the corresponding effective absorption bandwidth (EAB < −10 dB) up to 4.7 GHz (13.3–18.0 GHz). The fascinating MA properties of etched Fe/FeN/Fe3C@GN nanoparticles may be attributed to the cooperative effect of several points: (i) The NH3 plasma etch introduces a large number of polar functional groups, which can be regarded as the polarization center to produce more polarization loss; (ii) The appropriate dielectric loss and impedance matching achieve a good balance, and the abundant heterogeneous interface significantly enhances the polarization relaxation loss; (iii) The existence of hetero-nanostructure further improves the multiple reflections and scattering of the propagating microwaves. In addition, this work provides a new strategy for the design and fabrication of core-shell MA materials.

Synthesis and Late-Stage Modification of (-)-Doliculide Derivatives Using Matteson's Homologation Approach.

(-)-Doliculide, a marine cyclodepsipeptide derived from the Japanese sea hare, Dolabella auricularia, exhibits potent cytotoxic properties, sparking interest in the field of synthetic chemistry. It is comprised of a peptide segment and a polyketide moiety, rendering it amenable to Matteson's homologation methodology. This technique facilitates the diversification of the distinctive polyketide side chain, thereby permitting the introduction of functional groups in late stages for modifications of the derived compounds and studies on structure-activity relationships.

Late-stage guanine C8–H alkylation of nucleosides, nucleotides, and oligonucleotides via photo-mediated Minisci reaction

Chemically modified nucleosi(ti)des and functional oligonucleotides (ONs, including therapeutic oligonucleotides, aptamer, nuclease, etc.) have been identified playing an essential role in the areas of medicinal chemistry, chemical biology, biotechnology, and nanotechnology. Introduction of functional groups into the nucleobases of ONs mostly relies on the laborious de novo chemical synthesis. Due to the importance of nucleosides modification and aforementioned limitations of functionalizing ONs, herein, we describe a highly efficient site-selective alkylation at the C8-position of guanines in guanosine (together with its analogues), GMP, GDP, and GTP, as well as late-stage functionalization of dinucleotides and single-strand ONs (including ssDNA and RNA) through photo-mediated Minisci reaction. Addition of catechol to assist the formation of alkyl radicals via in situ generated boronic acid catechol ester derivatives (BACED) markedly enhances the yields especially for the reaction of less stable primary alkyl radicals, and is the key to success for the post-synthetic alkylation of ONs. This method features excellent chemoselectivity, no necessity for pre-protection, wide range of substrate scope, various free radical precursors, and little strand lesion. Downstream applications in disease treatment and diagnosis, or as biochemical probes to study biological processes after linking with suitable fluorescent compounds are expected.

Constructing Covalent Organic Polymers through Dative B─N Bonds: Synthesis, Single Crystal Structures, and Physical Properties

AbstractGrowing single crystals of covalent organic polymers (COPs) for single‐crystal X‐ray diffraction analysis is very important and highly desirable because such strategy provides a deep understanding of crystallization kinetics and the structure‐property relationship of COPs. Based on the strategy that dynamic covalent bonds can allow self‐correction of structures during crystal growth, single crystals of two COPs (CityU‐15 and CityU‐16) based on dative boron‐nitrogen (B─N) bonds have been successfully obtained. Detailly, tetra(4‐pyridyl)tetrathiafulvalene (TTF(py)4) and tetra(4‐pyridyl)porphine (TPYP) are employed as N‐donor ligands to react with 1,4‐bis(benzodioxaborole) benzene to prepare single crystals of COPs, named as CityU‐15 and CityU‐16, respectively. CityU‐16 exhibits enhanced stability compared to CityU‐15, and the size of CityU‐16 single crystals can reach up to 0.7 cm. CityU‐15 shows good recyclability and reveals noticeable photosensitivity upon iodine doping. After treatment with iodine, both crystals display obvious color changes. Specially, the device based on I2‐treated CityU‐15 exhibits excellent low‐voltage operation and low energy consumption of 3.3 fJ, facilitating the development of artificial vision. This work highlights the successful introduction of functional groups into B‐N‐containing COPs, opening up new avenues for expanding their applications.

Efficient CO2 capture and separation in TpPa COFs: Synergies from functional groups and metal Li

Covalent organic frameworks (COFs) have emerged as promising materials for CO2 capture and separation owing to their exceptional structural stability. Herein, grand canonical Monte Carlo simulation (GCMC) and density functional theory (DFT) were used to first screen the most favorable functional group in the COFs consisting of 1,3,5-triformylphloroglucinol (Tp) and p-phenylenediamine (Pa) functionalized with –OH, –COOH, and –SO3H, respectively (TpPa-X). Subsequently, the H atoms of –SO3H, the best functional group, were replaced by Li atoms to form –SO3Li, revealing the synergies of functional group –SO3H and Li modification on selective CO2 capture. TpPa-OLi/COOLi were also constructed to confirmed the universality of this synergistic effect. The introduction of functional groups enhanced the CO2 capture and separation performances by creating a more suitable pore environment. The Li introduction increased the structural polarity and provided strong adsorption sites, further improving the selective CO2 capture performance. Notably, TpPa-SO3Li exhibited a remarkable CO2 adsorption capacity of 136.11 cm3 cm−3 with the CO2 over N2/CH4 selectivity of 264.22/164.38, respectively, at 298 K and 1.0 bar. Structural stabilities, pore characteristics, gas adsorption distribution, isothermal adsorption heat, and interactions were adopted to reveal the synergistic effect between functional groups and Li in enhancing CO2 capture and separation.

Improving Biocompatibility of Polyurethanes Apply in Medicine Using Oxygen Plasma and Its Negative Effect on Increased Bacterial Adhesion.

Polyurethanes (PUs) are versatile polymers used in medical applications due to their high flexibility and fatigue resistance. PUs are widely used for synthetic blood vessels, wound dressings, cannulas, and urinary and cardiovascular catheters. Many scientific reports indicate that surface wettability is crucial for biocompatibility and bacterial adhesion. The use of oxygen plasma to modify PUs is advantageous because of its effectiveness in introducing oxygen-containing functional groups, thereby altering surface wettability. The purpose of this study was to investigate the effect of the modification of the oxygen plasma of polyurethane on its biocompatibility with lung tissue (A549 cell line) and the adhesion of Gram-positive bacteria (S. aureus and S. epidermidis). The results showed that the modification of polyurethane by oxygen plasma allowed the introduction of functional groups containing oxygen (-OH and -COOH), which significantly increased its hydrophilicity (change from 105° ± 2° to 9° ± 2°) of PUs. Surface analysis by atomic force microscopy (AFM) showed changes in PU topography (change in maximum height from ∼110.3 nm to ∼32.1 nm). Moreover, biocompatibility studies on A549 cells showed that on the PU-modified surface, the cells exhibited altered morphology (increases in cell surface area and length, and thus reduced circularity) without concomitant effects on cell viability. However, serial dilution and plate count and microscopic methods confirmed that plasma modification significantly increased the adhesion of S. aureus and S. epidermidis bacteria. This study indicate the important role of surface hydrophilicity in biocompatibility and bacterial adhesion, which is important in the design of new medical biomaterials.

Quantum capacitance, structural, optical and electronic properties of Zr2CT2 (T = F, P, Cl, Se, Br, O, S, OH) MXenes: A DFT study

Surface functionalization with termination functional groups plays a crucial role in the design of supercapacitors and electrode materials, whereas the understanding of the relevant mechanisms is still rather limited. Here, the quantum capacitance, work function and the related electronic and optical properties of eight functionalized MXenes Zr2CT2 monolayers (with functional group T = O, F, S, Cl, Br, OH, P and Se) are comprehensively investigated, by employing the first-principle calculations. All systems except Zr2CP2 are found to exhibit good stability. Modification with oxygen functional groups makes Zr2C change from metal to semiconductors. Surface functionalization modifies the work function of the MXenes by altering the Fermi level and the associated electron transfers. Particularly, the extremely low work function of Zr2C(OH)2 may enhance its power efficiency in optoelectronic fields. Introduction of functional groups may tune the density of electronic states near the Fermi level and effectively modulate the quantum capacitance and type of electrode materials. Zr2C suitable for symmetric supercapacitors and the modified systems applicable for potential anode or cathode materials are illustrated. The types of these electrode materials would not change in a wide voltage range. Further analyses on the optical properties and Bader charge are conducted for these materials.

Boosting CO2 chemical fixation over MOF-808 by the introduction of functional groups and defective Zr sites.

CO2 cycloaddition has emerged as a promising approach for producing value-added cyclocarbonates and mitigating greenhouse gas emissions. Although MOF-808 serves as a stable catalyst for cycloaddition, its limited activity constrains broader applications. Through the modification with a fluoride group via a ligand exchange method, F-MOF-808-1.5 exhibits exceptional performance, achieving a 98.8% conversion with 97.8% selectivity to epichlorohydrin carbonate-marking a substantial 100% improvement compared to pristine MOF-808. The defective Zr sites and the electron-withdrawing groups synergistically promote the ring opening of epoxides. Furthermore, the catalyst demonstrates high stability over multiple reaction cycles. Notably, without adding solvents and co-catalysts, F-MOF-808-1.5 outperforms most reported MOF-based catalysts.

Recent advancement in the synthesis of quinoline derivatives via multicomponent reactions.

The synthesis of quinoline derivatives through multicomponent reactions (MCRs) has emerged as an efficient and versatile strategy in organic synthesis. MCRs offer the advantage of constructing complex molecular architectures in a single step, utilising multiple starting materials in a convergent manner. This review provides an overview of recent advancements in the field of quinoline synthesis via MCRs. Various MCRs, such as the Povarov reaction, the Gewald reaction, and the Ugi reaction have been successfully employed for the synthesis of diverse quinoline scaffolds. These methodologies not only showcase high atom economy but also allow the incorporation of structural diversity into the final products. The versatility of MCRs enables the introduction of functional groups and substitution patterns tailored to specific applications. This review highlights the significance of quinoline derivatives in medicinal chemistry, materials science, and other interdisciplinary areas. The continuous innovation and development of novel MCR-based approaches for quinoline synthesis hold great promise for the rapid and efficient generation of valuable compounds with a wide range of biological and physicochemical properties.

Elucidating The Horizontal Orientation Mechanism of Emissive Transition Dipole Moment in A Series of Stick‐Like Delayed Fluorescent Emitters for Ultra‐High‐Efficiency OLEDs

AbstractThe horizontal orientation of the emissive transition dipole moment (TDM) of emissive molecules is a crucial factor in improving the efficiency of organic light‐emitting diodes (OLEDs). However, the mechanism of this horizontal orientation remains unclear. Herein, to elucidate the horizontal orientation mechanism of the TDM of the molecules in thermally activated delayed fluorescent (TADF) emitters, the relationship between the horizontal orientation ratio (Θ) of the TDM and the key parameters of stick‐like TADF emitters dispersed in carbazole‐based host materials is systematically and quantitatively investigated. The introduction of functional groups containing weak CH/n (n = O, N) hydrogen bonds into the host material is found to significantly increase the Θ values up to 30%. The physical parameters of the dispersed emitter exhibit a strong relationship with the Θ values, with the following influence order: glass transition temperature (Tg) ≥ total surface area of the largest π‐plane and the corresponding parallel π‐plane &gt; molecular weight &gt; aspect ratio &gt; permanent dipole moment. The Tg value of the host material is another key parameter determining the Θ values. By using a P=O‐based host material, namely mCP2PO, a high PLQY of 97%, a high Θ value of 88%, and a sky‐blue OLED with an EQE of 37.6% are simultaneously realized.

Chemically Modified Starches as Food Additives.

Starch is a renewable and multifunctional polysaccharide biopolymer that is widely used both in the food industry and other areas of the economy. However, due to a number of undesirable properties in technological processes, it is subjected to various modifications. They improve its functional properties and enable the starch to be widely used in various industries. A modified starch is a natural starch that has been treated in a way that changes one or more of its initial physical and/or chemical properties. Chemical modification consists of the introduction of functional groups into starch molecules, which result in specific changes in the physicochemical and functional properties of starch preparations. The bases of chemical modifications of starch are oxidation, esterification or etherification reactions. In terms of functionality, modified preparations include cross-linked and stabilized starches. These starches have the status of allowed food additives, and their use is strictly regulated by relevant laws. Large-scale scientific research is aimed at developing new methods of starch modification, and the use of innovative technological solutions allows for an increasingly wider use of such preparations. This paper characterizes chemically modified starches used as food additives, including the requirements for such preparations and the directions of their practical application. Health-promoting aspects of the use of chemically modified starches concerning resistant starch type RS4, encapsulation of bioactive ingredients, starch fat substitutes, and carriers of microelements are also described. The topic of new trends in the use of chemically modified starches, including the production of biodegradable films, edible coatings, and nanomaterials, is also addressed.

Application of chitosan-based materials in wastewater treatment

Chitosan, as a natural polysaccharide material, plays a great role in the field of wastewater treatment due to its good biodegradability, antimicrobial activity, and other properties. However, it may have some differences in the processes of adsorption, flocculation, and membrane separation. We comprehensively describe the application effect and mechanism of action of chitosan-based materials on the above three major water treatment processes. In the adsorption process, chitosan-based adsorbents such as hydrogels and chitosan beads are prepared by cross-linking, impregnation, and the introduction of functional groups. These chitosan-based materials exerted efficient removal performance in the adsorption of heavy metals, organic dyes, anionic pollutants, etc., which was attributed to their large specific surface area and abundant functional groups. In the flocculation process, the chitosan-based materials were modified by grafting and modifying their shape, while heavy metal ions, organic dyes, and algae were removed using processes such as chelation and charge neutralization. In the membrane separation process, a number of nanofiltration and microfiltration membranes were created by coating chitosan ions, and physicochemical modification was done for the separation of heavy metal ions and emulsified oil droplets in water to improve the fouling resistance and retention rate of the membrane materials. This paper reviews the application of chitosan-based materials in wastewater treatment and proposes that in-depth studies on their toxicity and reusability should be conducted in the future, with a view to playing a role in areas such as the removal of malodorous water odors.

Butterfly-Shaped Dibenz[a,j]anthracenes: Synthesis and Photophysical Properties.

A strategy for the synthesis of dibenz[a,j]anthracenes (DBAs) from cyclohexa-2,5-diene-1-carboxylic acids is presented. Our approach involves sequential C-H olefination, cycloaddition, and decarboxylative aromatization. In the key step for DBA skeleton construction, the bis-C-H olefination products, 1,3-dienes, are utilized as substrates for [4 + 2] cycloaddition with benzyne. This concise synthetic route allows for regioselective ring formation and functional group introduction. The structural features and photophysical properties of the resulting DBA molecules are discussed.

Enhanced CO2 capture in partially interpenetrated MOFs: Synergistic effects from functional group, pore size, and steric-hindrance

Excessive CO2 emissions have contributed to global environmental issues, driving the development of CO2 capture adsorbents. Among various candidates, metal–organic frameworks (MOFs) are considered the most promising due to their unique microporous structure. Herein, a series of partially interpenetrated MOFs named UPC-XX were built to investigate the continuous enhancement in CO2 capture performance via synergistic effects from functional group, pore size, and steric-hindrance using theoretical calculations. It’s showed that the introduction of functional groups improved the structure polarity and created more adsorption sites, thus, enhanced CO2 capture capacity. The pore size modification augments the exposure of adsorption sites to mitigate the negative impact of pore space and surface area reduction caused by the introduction of functional groups, thereby further increasing the CO2 capture capacity. The steric-hindrance effect optimized the adsorption sites distribution, which hasn’t been considered in the previous two regulation strategies, thus, further increased the CO2 capture capacity. The results underscore UPC-MOFs as outstanding adsorbent materials, among the UPC-MOFs, UPC-OSO3-steric exhibited the highest CO2 capture capacity of 12.69 mmol/g with selectivities of 1142.41 (CO2 over N2) and 507.42 (CO2 over CH4) at 1.0 bar, 298 K. And the synergistic effect mechanisms of functional group, structure size, and steric hindrance were elucidated through theoretical calculations analyzing pore characteristics, gas distribution, isosteric heat, and van der Waals/Coulomb interactions.

Vectorial On‐Surface Synthesis of Polar 2D Polymer Crystals

AbstractThe asymmetric introduction of functional groups into polymers is promising due to its potential to provide novel electronic and magnetic properties. Though traditional on‐surface bottom‐up synthesis has succeeded in creating various types of polymers, it struggles at realizing asymmetry due to the difficulty of stereoregular polymerization and the tendency for overall polarity cancellation during agglomeration. Here, enabled by the low halogen‐contaminated metal surfaces provided by two‐zone chemical vapor deposition, “compass” precursors possessing three independent bonding, edge, and dipole vectors undergo isotactic polymerization via the vectorial self‐assembly of chiral precursor diradicals without the need for chiral catalysts required in conventional in‐solution polymerization. The isotactic polymers exhibit polar 2D crystalline structures due to the hetero‐edge CH–π interaction between the standing phenyl and butoxy group surpassing the homo‐edge interactions of π–π and CHCH. The developed vectorial on‐surface synthetic technique not only paves the way to the realization of stereoregular control but also unlocks unprecedented crystal engineering.

Bio-Inspired Subnanofluidics: Advanced Fabrication and Functionalization.

Biological ion channels can realize high-speed and high-selective ion transport through the protein filter with the sub-1-nanometer channel. Inspired by biological ion channels, various kinds of artificial subnanopores, subnanochannels, and subnanoslits with improved ion selectivity and permeability are recently developed for efficient separation, energy conversion, and biosensing. This review article discusses the advanced fabrication and functionalization methods for constructing subnanofluidic pores, channels, tubes, and slits, which have shown great potential for various applications. Novel fabrication methods for producing subnanofluidics, including top-down techniques such as electron beam etching, ion irradiation, and electrochemical etching, as well as bottom-up approaches starting from advanced microporous frameworks, microporous polymers, lipid bilayer embedded subnanochannels, and stacked 2D materials are well summarized. Meanwhile, the functionalization methods of subnanochannels are discussed based on the introduction of functional groups, which are classified into direct synthesis, covalent bond modifications, and functional molecule fillings. These methods have enabled the construction of subnanochannels with precise control of structure, size, and functionality. The current progress, challenges, and future directions in the field of subnanofluidic are also discussed.