Effects Of Different Functional Groups Research Articles

Investigation of Anticancer Properties of 2-benzylidene-1-indanone and Its Derivatives by DFT and Molecular Docking

In this study, 2-benzylidene-1-indanone and its derivatives, which is a chalcone compound and contains indanone in its structure, were examined. Quantum chemical parameters for these compounds were calculated with the B3LYP method and the 6-31G(d) basis set and evaluated for their biological activity. The effect of different functional groups (F, Cl, Br, CF3, CH3 and OCH3) attached to the 2-benzylidene-1-indanone compound on biological activity was investigated. Some quantum chemical parameters such as highest energy filled molecule orbital energy (EHOMO), lowest non-bonding empty molecule orbital energy (ELUMO), energy gap (ΔE), hardness (η), softness (σ), global molecular electrophilicity (ω) index, global molecular nucleophilicity (ɛ) index, electron-accepting (ω+) and electron-donating (ω-) electrophilicity index were calculated for the biological activities of the compounds. Frontier molecular orbitals and molecular electrostatic potential (MEP) maps were interpreted. The biological activities of 2-benzylidine-1-indanone and some of its derivatives bearing the 1-indanone skeleton were evaluated by performing molecular docking studies with the target protein PDB ID = 1HJD corresponding to the melanoma cell line. The activity ranking obtained with quantum chemical parameters was found to be compatible with the binding energies obtained from docking results.

Construction of ligand functionalized MIL-101(Fe)-R and mechanism of efficient removal of chlortetracycline hydrochloride: Experiment and DFT calculation

Functionalization of ligands is an effective strategy to enhance the adsorption performance of adsorbents. In this study, MIL-101(Fe)-R (R = -H, –OH, –NH2, and –NO2) was selected as a platform for systematically studying the impact of functionalization on the adsorption behavior of chlortetracycline (CTC). A series of characterizations were conducted on the prepared MIL-101(Fe)-R to clarify the influence of organic linkers on the microscopic morphology, pore structure, and surface functionality of the adsorbents. Additionally, the effects of different functional groups on the adsorption behavior of MIL-101(Fe)-R were compared to screen for MOFs with high efficiency in removing CTC. Experimental results showed that the maximum adsorption capacities (qm) of MIL-101(Fe), MIL-101(Fe)–NH2, MIL-101(Fe)–OH, and MIL-101(Fe)–NO2 were 418.980 mg/g, 559.854 mg/g, 187.387 mg/g, and 154.131 mg/g, respectively. Among them, MIL-101(Fe)–NH2 exhibited a higher mass transfer rate (reaching equilibrium in 15 min). Based on apparent adsorption behavior, adsorption kinetics, isotherm and thermodynamic studies, as well as FTIR and XPS characterizations before and after adsorption, the performance modulation mechanism of MIL-101(Fe)-R in CTC adsorption was discussed in detail. Combined with density functional theory (DFT) calculations, the host–guest interaction controlling the adsorption behavior was understood at the molecular level, demonstrating the optimal binding sites of the adsorbents. This study provides guidance for the design of efficient MOF adsorbents for antibiotic wastewater treatment.

Polystyrene nanoplastics with different functional groups and charges have different impacts on type 2 diabetes

BackgroundIncreasing attention is being paid to the environmental and health impacts of nanoplastics (NPs) pollution. Exposure to nanoplastics (NPs) with different charges and functional groups may have different adverse effects after ingestion by organisms, yet the potential ramifications on mammalian blood glucose levels, and the risk of diabetes remain unexplored.ResultsMice were exposed to PS-NPs/COOH/NH2 at a dose of 5 mg/kg/day for nine weeks, either alone or in a T2DM model. The findings demonstrated that exposure to PS-NPs modified by different functional groups caused a notable rise in fasting blood glucose (FBG) levels, glucose intolerance, and insulin resistance in a mouse model of T2DM. Exposure to PS-NPs-NH2 alone can also lead the above effects to a certain degree. PS-NPs exposure could induce glycogen accumulation and hepatocellular edema, as well as injury to the pancreas. Comparing the effect of different functional groups or charges on T2DM, the PS-NPs-NH2 group exhibited the most significant FBG elevation, glycogen accumulation, and insulin resistance. The phosphorylation of AKT and FoxO1 was found to be inhibited by PS-NPs exposure. Treatment with SC79, the selective AKT activator was shown to effectively rescue this process and attenuate T2DM like lesions.ConclusionsExposure to PS-NPs with different functional groups (charges) induced T2DM-like lesions. Amino-modified PS-NPs cause more serious T2DM-like lesions than pristine PS-NPs or carboxyl functionalized PS-NPs. The underlying mechanisms involved the inhibition of P-AKT/P-FoxO1. This study highlights the potential risk of NPs pollution on T2DM, and provides a new perspective for evaluating the impact of plastics aging.

Insights into behaviors of functional groups in biomass derived products during aqueous phase reforming over Ni/α-MoO3 catalysts

Aqueous phase reforming (APR) of biomass-derived products has been widely applied for hydrogen generation, chemicals production, and wastewater treatment. Despite its widespread application, the complexity of the raw materials and reaction mechanisms significantly complicates the APR process, impeding its development. This study investigated the APR performance of biomass-derived products using Ni/α-MoO3 catalysts toward hydrogen production and pollutant control, conducted at a temperature of 225 °C and a residence time of 30 min, thus comprehensively understanding the effect of different functional groups. The results showed that the amide (R–HCON) exhibited superior hydrogen production potential during APR. In terms of total organic carbon (TOC) removal, ether showed a 98.10% removal efficiency without a catalyst, whereas the presence of catalyst greatly enhanced the TOC removal efficiency of acetaldehyde (-CHO) from 62.26% to 86.68%. The performed APR of biomass-derived products on Ni/α-MoO3 catalysts primary resulted in the presence of N, N-Dimethylformamide (HCON-(CH3)2), and aminobenzene (Ph-NH2) for Ni leaching with a lower concentration. The carbon deposition on the catalyst primarily resulted from the combined effects of various compounds and the oxygen vacancies within the catalysts. This study aims to provide novel insights into the APR process for both biomass and biomass-derived materials.

Recent advances in the synthesis of pyrazoline derivatives from chalcones as potent pharmacological agents: A comprehensive review

The pyrazoline scaffold plays a vital role in heterocyclic chemistry as a fundamental building block in both organic and medicinal chemistry. A pyrazoline scaffold is composed of an endocyclic double bond, two nitrogen atoms, and five different types of bonds. It is a significant chemical fragment and exhibits various bioavailabilities, allowing the synthesis of a range of diverse compounds with promising biological potential. Over the past decade, extensive research efforts have been devoted to investigating the therapeutic potentials of pyrazoline scaffolds, encompassing their antibacterial, anti-inflammatory, analgesic, cytotoxic, and anti-tumor activities. Moreover, in the presence of a unique chemical structure, pyrazolines have made it easier to produce new substitutions with low toxicity as compared to their natural analogue. The current review focuses on the recent progress in the synthesis of pyrazoline scaffolds from chalcones, with an emphasis on their possible biological functions. The study identifies a diverse range of pyrazoline derivatives that exhibit promising biological properties and have been successfully reported in various studies. The primary objective is to determine the chemical groups and structural modifications that enhance their bioactivity, low toxicity, and handling. Furthermore, the review explores the bioavailability, synthetic challenges, and progress made in utilising pyrazoline derivatives in pharmaceutical and synthetic chemistry from 2017 to 2023. The different biological potentials of various substituted pyrazolines are reported here such as 1,4-dimethylpiperazine, 2-(2-methyl-1H-benzo[d]imidazol-1-yl)acetohydrazide, 1-methyl-4-phenylpiperazine, 4,5-dihydrooxazole, 2H-chromen-2-one, 2-(4-chlorophenyl)-5-methyl-4,5-dihydrooxazole, benzo[d]thiazole, ethoxybenzene, and 1-bromo-4N,N-dimethylaniline. The review also discusses the effects of different functional groups, such as OCH3, OH, NO2, CF3, and halogens, added to different positions of the pyrazoline scaffold.

Influence of polymers with surfactant properties as pour point depressants on the cold flow properties of diesel fuel

Polymers and surfactants are increasingly applied to improve the cold flow properties of diesel fuel. However, their depressive effects are closely related to the molecular structure of the structuring units. In this study, the structural properties of surfactants were applied to synthesise a series of polymers consisting of tetradecyl methacrylate and ether compounds as structural units, with the long alkyl chain and ether compounds acting as hydrophobic and hydrophilic groups, respectively. The polymers consisting of tetradecyl methacrylate and ether compounds combined the advantages of polymers and surfactants in improving the cold flow properties of diesel. Besides, the effects of different functional groups, molar ratios and additive amounts on the improvement of diesel fuel low–temperature fluidity were investigated. The results indicated that 1500 ppm polymer with tetradecyl methacrylate and allyl glycidyl ether as structural monomers at a molar ratio of 6:1 as polymer pour point depressant (PPD) showed a greater enhancement of cold filter plugging point and solid point of diesel (ΔCFPP = 12 ℃, ΔSP = 17 ℃). The molecular structures of efficient pour point depressants were screened and the polymer composition was broadened. Finally, differential scanning calorimeter, rheological and polarising optical microscopy were used to analyse the changes in wax crystals size and morphology in pure diesel and diesel treated with polymer PPDs, and a mechanism for polymer PPDs with surfactant structural properties to change the crystallisation and aggregation behaviour of wax crystals was inferred.

Synthesis of Pyridin-1(2H)-ylacrylates and the Effects of Different Functional Groups on Their Fluorescence.

While fluorescent organic materials have many potential as well as proven applications and so have attracted significant attention, pyridine-olefin conjugates remain a less studied subset of such systems. Herein, therefore, we report on the development of the straightforward syntheses of pyridin-1(2H)-ylacrylates and the outcomes of a study of the effects of substituents on their fluorescent properties. Such compounds were prepared using a simple, metal-free and three-component coupling reaction involving 2-aminopyridines, sulfonyl azides and propiolates. The fluorescent properties of the ensuing products are significantly affected by the positions of substituents on the cyclic framework, with those located in central positions having the greatest impact. Electron-withdrawing groups tend to induce blue shifts while electron-donating ones cause red shifts. This work highlights the capacity that the micro-modification of fluorescent materials provides for fine-tuning their properties such that they may be usefully applied to, for example, the study of luminescent materials.

Study on the microscopic mechanism of adsorption and diffusion of hydrocarbon oil drops on coal surface using molecular dynamics simulations

AbstractFlotation of fine coal particles usually uses oil collectors, but the micromechanisms need to be more defined due to the complex structure and abundant functional groups on the surface of coal bodies [Correction added after first online publication on 16 October 2023: “refined” was changed to “defined” in the first sentence of the article abstract.]. The adsorption spreading behavior and interfacial properties of nonpolar oil drops on flat low‐order coal (LOC) and high‐order coal (HOC) surfaces were investigated in depth using molecular dynamics (MD) simulations, while the effects of different functional groups on LOC surfaces were also considered. The results showed that the contact angle, contact area and interaction energy of oil drops adsorbed on the LOC and HOC surfaces at simulated equilibrium in aqueous environment were 77.68°, 621.49 Å2, −140.94 kcal/mol; 53.98°, 962.14 Å2, and −195.13 kcal/mol, respectively. The smaller the equilibrium contact angle between the oil drops and the surface, the larger the contact area and the larger the absolute value of the interaction energy, the better the spreading effect of the oil drops and the easier the surface is to flotation. Compared with the HOC surface, the oil drops could not displace the water molecules on the LOC surface better and spread poorly on its surface, and the migration rate was higher. This was caused by the abundant functional groups on the surface of LOC. The type of functional group significantly affects the interaction of nonpolar oil drops with hydrophilic surfaces, with the order of adsorption strength being CH3 > COCH3 > OH > COOH. The formation of a dense hydrated film of oil drops on the COOH surface was an important reason for the difficulty of flotation on the LOC surface. MD elucidated the mechanism of action of nonpolar oil collectors on LOC and HOC surfaces, which is a guide for efficient flotation on LOC surfaces.

Contributions of Different Functional Groups to Particles in Electrophoretic Display

Electrophoretic display (EPD) has excellent research potential because of its ultra-low power consumption and friendliness to the eyes. To obtain efficient electrophoretic inks, researchers need to understand the charging mechanism of electrophoretic particles. In this work, several silane coupling agents with similar main chains but different functional groups on the side chains were used to investigate the effects of different functional groups on the charging properties of the electrophoresis particles. The results showed that silane coupling agents containing amino groups resulted in the most positively charged particles, and those containing carboxyl groups resulted in the most negatively charged particles. More importantly, after introducing many additional amino groups by grafting, it was found that the charge on the particle surface was only slightly elevated, indicating that the polymer layer grafted on the particle surface would cover the functional groups inside and hinder the acid-base interactions between the functional groups in the inner layer and the charge control agent. The findings of these results may contribute to the precise design of materials for electrophoretic display.

Cyclodextrin modified with different groups to enhance the drug delivery efficiency of gold nanoparticles to treat cancer

The aim of this research is to investigate the influence of different functional groups of β-cyclodextrin (CD) in functionalizing gold nanoparticles. The functionalized nanoparticles are then utilized for loading the 5-fluorouracil (5-FU) drug and evaluating their in vitro anticancer activity. A two-step method was employed to synthesize Mono-6-(1,3-trimethylenediamine)-6-deoxy-β-cyclodextrin (TMACD), which was further utilized for fabricating gold nanoparticles (AuNPs) using ultrasound-assisted synthesis. To investigate effect of different functional groups of β-cyclodextrin (CD) on drug delivery efficiency, three cyclodextrin derivatives, namely β-cyclodextrin (5-FU@AuNPs/CD), 2-hydroxylpropyl-β-cyclodextrin (5-FU@AuNPs/HPCD), and TMACD (5-FU@AuNPs/TMACD) were utilized to load 5-FU. Among them, the nanocomposite AuNPs/TMACD exhibited the highest associate efficiency and loading efficiency which were confirmed by analytic techniques such as FTIR, PXRD, TEM. Moreover, the release behavior of 5-FU from the nanocomposites was investigated at pH 7.4, revealing that all AuNPs/CDs nanocomposites effectively protected the drug with a low release percentage ranging from 23.13% to 29.45%. Docking model analysis indicated that the 5-FU ligand formed six hydrogen bonds and interacted favorably with the HPCD molecule. In the in vitro cell viability assay, both nanocomposites, 5-FU@AuNPs/CD and 5-FU@AuNPs/TMACD, not only demonstrated effective anticancer activity against breast cancer cells (MCF-7) but also exhibited minimal toxicity towards normal cell lines. Remarkably, the results revealed that 5-FU@AuNPs/TMACD displayed the highest efficacy in suppressing the growth of the breast cancer cells. These findings highlight the considerable potential of amine-derivative cyclodextrin-capped AuNPs as exceptionally efficient carriers for anticancer drugs, offering promising applications in both diagnosis and therapy.

Investigation of the correlation between molecular structures with high-temperature and salt resistance for acrylamides polymer in drilling fluid

Deep oil and gas are essential alternative resources for future energy sources, but the lack of high temperature and high salt resistance mechanisms and agents significantly limits their development. Copolymers of six commonly used high-temperature and salt resistance monomers and acrylamide with similar molecular weights were prepared to improve oil recovery in deep reservoirs. The effects of different functional groups on the high-temperature and salt resistance of polymers were revealed by the drilling fluid and elemental analysis, TOC test, Zeta potential, particle size, and other analytical methods. Experimental results indicate that the pyrrole ring groups, quaternary amine groups, long-chain sulfonate groups, and benzenesulfonic acid groups can effectively improve the high-temperature stability of polymers in an aqueous solution. Quaternary ammonium groups and pyrrole rings can enhance the polymer adsorption with clay under high temperatures and high salinity conditions due to charge attraction. However, these functional groups hinder the clay dispersion and reduce the stability of drilling fluids. Hydration groups, such as sulfonic and carboxylic acid groups, can better maintain the colloidal stability of drilling fluids under high temperatures and high salinity, and benzene sulfonic acid groups are the optimal hydration groups. After the polymer is adsorbed on the clay surface, the benzene sulfonic acid group assists in forming a thicker hydration film on the clay surface, effectively hindering the damage of high temperature and high salinity on the clay. The findings and observations of this study provide theoretical support for the development of high-temperature and salt resistance polymers for water-based drilling fluids of ultra-deep wells.

Synthesis of Citronellol-Derived Antibacterial Polymers and Effect of Thioether, Sulfoxide, Sulfone, and Ether Functional Groups on Their Bactericidal Activity

Citronellol-derived methacrylate polymers with four side chain interconnecting groups of different polarities (PCHM-Xs) are synthesized to prepare bio-based bactericidal polymers. The PCHM-X bactericidal activities are significantly affected by the different functional groups determining the interaction between the polymer chain and bacterial membrane that disrupts the membrane integrity causing cytoplasmic leakage, the main contributor to the polymer antibacterial properties. PCHM-SO, with a large dipole moment and strong hydrogen bonding ability, shows the best bactericidal activity among PCHM-Xs due to the strongest interactions with the bacterial membrane components. A sulfoxide-group-containing polymer with excellent bactericidal activity (99.99%) and the systematic study of the effect of different functional groups on the bactericidal activity are first reported herein.

Effect of Functional Groups on Protein Adsorption Performance of Membrane Adsorbers

Functional groups on support membranes are important for the preparation of high-performance membrane adsorbers (MAs). In this work, the effects of different functional groups on support membranes on the adsorption performance of MAs were studied through surface modifications such as alkali treatment, oxidation treatment and polydopamine (PDA) deposition. Our experiment results indicate that chemical bonds are prone to form between C-F on PVDF membrane and amine groups on PEI, which serves to improve the protein adsorption capacity. Furthermore, PDA deposition has the potential to enhance protein adsorption capacity. Introducing a PDA layer on a support membrane with uniform pore size distribution shows potential to improve protein adsorption capacity.

Enantioseparation of β-Blockers Using Silica-Immobilised Eremomycin Derivatives as Chiral Stationary Phases in HPLC

The regularities of chromatographic retention and separation enantioselectivity of the selected β-blockers (propranolol, pindolol, alprenolol, atenolol, oxprenalol, metoprolol, clenbuterol, sotalol, pronethalol, salbutamol, and labetalol) were studied with eight chiral stationary phases (CSPs) in polar ionic mode (PIM) elution system. A range of novel CSPs was prepared by immobilisation of macrocyclic glycopeptide antibiotic eremomycin (E-CSP); structurally related antibiotics chloreremomycin (Chloro-E-CSP) and semi-synthetic oritavancin (O-CSP); and five eremomycin derivatives including amide- (Amide-E-CSP), adamantyl-2-amide- (Adamantylamide-E-CSP), eremomycin aglycon (EAg-CSP), eremosaminyl eremomycin aglycon (EEA-CSP), and des-eremosamynyl eremomycin (DEE-CSP) onto microspherical silica (Kromasil, particle size 5 micron, pore size 11 nm). The effect of different functional groups in eremomycin structure on chiral recognition of β-blockers was studied. The original E-CSP revealed moderate enantioseparation for all studied β-blockers. The presence of a free carboxylic group in a chiral selector molecule is found to be critical for the general retention of enantiomers as no separation enantioselectivity was recorded for Amide-E-CSP and Adamantyl-E-CSP. Modification of the aromatic system of eremomycin by the introduction of a chloro- substituent in the aromatic ring (Chloro-E-CSP) or a hydrophobic 4’-chlorobiphenylmethyl substituent to the disaccharide sugar residue (O-CSP) resulted in decreased enantioselectivity. The best enantioseparation of β-blockers was obtained for CSPs with eremosaminyl eremomycin aglycon and des-eremosamynyl eremomycin as chiral selectors.

The heteroaggregation behavior of nanoplastics on goethite: Effects of surface functionalization and solution chemistry

Nanoplastics have attracted extensive attention in recent years. However, little is known about the heteroaggregation behavior of nanoplastics on goethite (FeOOH), especially the contribution of surface functional groups. In this study, the heteroaggregation behavior between polystyrene nanoplastics (PSNPs) and FeOOH was systematically investigated under different reaction conditions. Moreover, the effect of different functional groups (-NH2, -COOH, and bare) of PSNPs and solution chemistry was evaluated. The results showed that PSNPs could heteroaggregate with FeOOH, and the heteroaggregation rate of PSNPs with surface functionalization was significantly faster. The removal of suspended PSNPs was enhanced with increasing NaCl or CaCl2 concentration. However, heteroaggregation was significantly inhibited with the increase of solution pH. The zeta potentials analysis, time-resolved dynamic light scattering (DLS) and heteroaggregation experiments suggested that the electrostatic force affected the heteroaggregation process significantly. Fourier transform infrared (FTIR) spectra proved that the adsorption affinity between PSNPs and FeOOH was stronger after surface functionalization, especially for CH, O-C=O, and -CH2- groups, indicating that chemical bonding also made a contribution during the heteroaggregation process. This work is expected to provide a theoretical basis for predicting the environmental behavior between PSNPs and FeOOH.

Rapid synthesis of cerium-UiO-66 MOF nanoparticles for photocatalytic dye degradation.

An unprecedented synthesis method is used to form a series of Ce-UiO-66-X (X = NH2, OH, H, NO2, COOH) metal-organic frameworks by precipitation from mixed solvents, with instantaneous crystallisation on combining separate solutions of ligands and metal precursors. This allows the first direct synthesis of Ce-UiO-66-OH. Powder X-ray diffraction (PXRD) shows that all materials are pure phase with a broadened profile that indicates nano-scale crystallite domain size. The effect of different functional groups on the benzene-1,4-dicarboxylate linker within the UiO-66 structure has been investigated on degradation of two cationic (methylene blue and rhodamine B) and two anionic (Congo red, and Alizarin red S) dyes under UV and visible light irradiation at room temperature. Analysis of the dye adsorption in the absence of light is accounted for using pseudo-first order kinetics, and the Ce-UiO-66-NH2, Ce-UiO-66-OH, and Ce-UiO-66-H materials display a considerable photocatalytic activity to degrade Alizarin red S and Congo red rapidly between 1 and 3 minutes. The materials show excellent photostability and recyclability under UV and visible light, with no loss of crystallinity seen by PXRD and activity maintained over 5 cycles, with 16 hours photostability for Ce-UiO-66-NH2.

Adsorption characteristic analysis of PAHs on activated carbon with different functional groups by molecular simulation.

As widespread organic pollutants in the environment, polycyclic aromatic hydrocarbons (PAHs) greatly threaten human health. The adsorption technology has become one of the main methods to deal with PAHs because of its low cost, simple design, and no secondary pollution. Among them, solid media have strong adsorption capacities for PAHs and are widely used. In this work, activated carbon was chosen as the solid adsorbent. The adsorption behavior of three PAHs (naphthalene, anthracene, and phenanthrene) on activated carbon was investigated at the molecular level by Grand Canonical Monte Carlo (GCMC) method. The effects of different functional groups (amino, carboxyl, hydroxyl, carbonyl, and hydrogen groups) and temperature effect on the adsorption isotherms and heat of adsorption of PAHs on activated carbon were calculated. The results showed that the carbonyl functional group increased the adsorption of PAH molecules by the most considerable amount among all the functional groups. Acid functional groups were more favorable to the adsorption of PAHs than alkali functional groups. The adsorption capacity and heat of adsorption of PAHs decreased when the temperature increased. The adsorption performance of bicyclic aromatic hydrocarbons was more influenced by temperature than that of tricyclic aromatic hydrocarbons.

Using Organosulfur Materials to Solve Critical Challenges Facing Lithium-Sulfur Batteries

The high abundance and environmental benignity of sulfur coupled with its high energy density of nearly 2,500 Wh kg-1 render the lithium-sulfur (Li-S) battery technology a sustainable energy storage solution for the future. Unfortunately, in Li-S batteries, the sulfur cathode suffers from poor electronic and ionic conductivity and the notorious polysulfide shuttle effect. Meanwhile, the anode suffers from continuous degradation owing to the high reactivity of Li metal. Organosulfur materials may present a way to overcome these limitations. Organic functional groups bound to sulfur could enhance electronic and ionic conductivity. Limiting the polysulfide order in an organosulfur material can minimize the shuttle effect. Furthermore, organic groups could stabilize the electrolyte-anode interface.Two studies on using organosulfur materials to overcome the challenges of Li-S will be presented. The first study shows a method to rationally design organosulfide polymers that can provide inherent Li-ion conductivity. The enhancement in ionic conductivity results in an improvement in performance under high-rate and high-loading conditions. The application of such materials in flexible Li-S batteries will be showcased. In the second study, a mechanistic understanding of how organosulfide-rich interphase at the Li-metal anode improves the stripping/plating efficiency will be elucidated. By understanding the effect of different functional groups on the efficiency of the anode, a set of design rules for developing organosulfide molecules that generate a stable interface will be proposed.

Effect of different functional groups on CH4 adsorption heat and surface free energy of vitrinite during coalification

Here vitrinite of various coal ranks was collected to study the characteristics of initial isosteric heat of adsorption (Qst0) and surface free energy (Δσ) by the isothermal methane-adsorbing at various temperatures on dry basis. The surface area of demineralized dry samples was examined for the calculation of Qst0 and Δσ, and the macromolecular structures of dry vitrinite samples were determined using Fourier transform infrared spectroscopy and 13C nuclear magnetic resonance experiments. The Qst0 shows no obvious correlations with oxygen-containing groups, however, there is a positive correlation between the alcoholic hydroxyl group (R–OH) and maximal surface free energy (Δσmax), indicating that the decreasing in R–OH content with the increasing coal rank can reduce adsorption capacity. Qst0 decrease as the amount of nonprotonated aromatic carbon attached to phenolic (including phenoxy or phenol groups) increases, indicating that phenoxy or phenol group loss with maturation is beneficial to increasing Qst0. As the degree of coal metamorphism increases, the aliphatic side chains gradually decline, inducing Qst0 initially decreases and then increases. For aromatic groups, with increases of aromatic carbons, aromatic bridgehead carbons, and ratio of aromatic CC to aromatic CH, Qst0 initially decreases and then increases.

Effects of various functional groups in graphene on the tensile and flexural properties of epoxy nanocomposites: a comparative study

In this article, we investigated the effects of different functional groups in graphene on the mechanical performance of epoxy nanocomposites fabricated using the in-situ polymerization method. This study considered pristine graphene and three different varieties of functionalized graphene (–NH2, –COOH, and –OH) with varying weight percent (i.e., 0.25, 0.5, and 1.0 wt%). The functional groups grafted of graphene have been confirmed through Fourier transforms infrared (FTIR) spectra. Microstructural features and fracture surfaces were also examined by field-emission scanning electron microscopy with energy-dispersive X-ray spectroscopy. In comparison to pure epoxy, –OH functionalized graphene/epoxy nanocomposites showed a maximum improvement of 37.24% in tensile strength and 38.05% in flexural strength. The improved mechanical properties of epoxy nanocomposites were attributed to homogeneous dispersion, graphene bridging, and better interfacial contact between epoxy and graphene. HIGHLIGHTS The effect of pristine and functionalized graphene on the mechanical properties of epoxy nanocomposites was studied. Nanocomposites were fabricated for three different wt% (0.25, 0.5, and 1.0) of graphene nanofillers. Field emission scanning electron microscopy (FE-SEM) with EDX was used to examine the microstructural features of fractured surfaces. Graphene enhanced the mechanical properties of epoxy nanocomposites.