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The mechanism of action of most drugs is based on their interaction with molecular targets in the organism, i.e., biological macromolecules such as proteins or nucleic acids. Factors influencing the strength of binding of a drug molecule to its biological target include the total number of interactions, their character, and the resulting binding energy. The value of binding energy is an essential parameter for estimating the strength of the interaction. The basic types of these intermolecular interactions are defined, schematically illustrated, and supported with data on binding energy in this review article. Other aspects of drug binding to molecular targets are also presented, e.g., the solvation of molecules in aqueous environment or the distance of interacting chemical functional groups. Knowledge of the structures of molecular targets and the progress of current models allows us to use these interactions to design new drugs. [ABSTRACT FROM AUTHOR]

The separation of Hg0 and HgCl2 with selective adsorbents is crucial for mercury speciation detection. KCl is commonly used but has a limited surface area, a short lifespan, and an unclear mechanism for Hg0/HgCl2 adsorption. Hence, KCl supported by γ‐Al2O3 to create a high‐surface‐area selective adsorbent to enhance practical performance was proposed and the selective adsorption mechanisms of Hg0 and HgCl2 through experimental investigations and density functional theory (DFT) calculations were elucidated. Compared to the total breakthrough of pure KCl, that of KCl/γ‐Al2O3 exhibits markedly selective adsorption efficacy on HgCl2, with a nearly complete breakthrough rate on Hg0 at a KCl‐to‐γ‐Al2O3 molar ratio of 1, attributed to their favorable porosity and dispersed active sites. The DFT results verify a weak van der Waals force between KCl and Hg0, indicating physisorption, while covalent bonding occurs between KCl and HgCl2, suggesting chemisorption. High‐resolution transmission electron microscopy (HRTEM) identifies two crystalline surfaces of 001 and 011 on the developed adsorbent. This clarifies three stable adsorption configurations: 001 Top‐Cl, 011 Top‐Cl, and 011 Cl–Cl bridge, with adsorption energies of −87.11, −110.74, and −174.91 kJ/mol, respectively. Analyses of the electronic structure and interaction region indicator (IRI) reveal that the Hg atom within HgCl2 forms covalent bonds with unsaturated Cl atoms on the KCl surface. Additionally, integrated crystal orbital Hamilton population (ICOHP) analysis and electron transfer results demonstrate that the interaction strength of the three configurations with HgCl2 follows the order of 011 Cl–Cl bridge > 011 Top‐Cl > 001 Top‐Cl. This matches the three different temperature peaks of 276, 231, and 120°C, respectively, in the analysis of the temperature‐programmed desorption of HgCl2 (HgCl2‐TPD). This study offers a novel insight on mercury speciation partitioning between Hg0 and HgCl2. [ABSTRACT FROM AUTHOR]

The high theoretical capacities and excellent redox activities motivate transitional metal sulfides (TMSs) to serve as promising anode materials for sodium‐ion batteries. However, TMSs would experience low electronic conductivity as well as notorious polysulfides dissolution and shuttle effect during charge/discharge processes, which leads to unsatisfactory rate capability and cycling stability. Herein, TMSs‐based anode materials with NiS2 nanoparticles tightly anchoring on nitrogen‐doped graphene (NiS2/NG) via the Ni–N covalent bond have been developed through an electrostatic self‐assembly approach between exfoliated positively charged layered double hydroxide and negatively charged graphene oxide nanosheets, followed by a sulfidation process. The strong coupling between conductive and active components enables NiS2/NG to possess good structural integrity, high ion/electron conductivity, and strong polysulfides adsorption capability, ensuring fast reaction kinetics and energetically stable performance. In consequence, the NiS2/NG delivers a high capacity of 664 mAh g−1 at 0.1 A g−1, good rate performance of 545 mAh g−1 at 2 A g−1, and excellent cycling stability with a retained capacity of 589.9 mAh g−1 after 1200 cycles at 0.5 A g−1, among the best results of reported TMSs‐based anodes. The study provides an effective strategy to design heterostructured materials with strong coupling interaction for high‐efficient‐stable sodium storage. [ABSTRACT FROM AUTHOR]

The anomalous density-temperature relationship of vitreous silica with low hydroxyl content is explained by the formation of medium-range ordering structure in the glass transition process. The ordered medium-range structure has the shape of a "nanoflake" and consists of two layers of SiO4 tetrahedra, bonded by O atoms located in the middle of the structure. The nanoflakes interact with their surrounding structures through both covalent chemical bonds and van der Waals bonds. In the formation of the van der Waals bonds, the orientation of SiO4 tetrahedra can change, which results in an increase in distance between the nanoflakes and their surrounding structures. Thus, there is a slight volume enlargement associated with the formation of nanoflakes. Since the nanoflakes' formation starts at a temperature near 1480 °C, and the population of the nanoflakes grows continuously as temperature decreases until about 950 °C, the bulk volume of silica glass increases in the temperature range from about 1480 °C to 950 °C. Therefore, the density anomaly of silica glass can be explained as a byproduct of forming of medium-range ordering structure in the silica glass transition.

Si is an important semiconductor material in the development of modern industry. With the miniaturization trend of semiconductor devices, the size of Si has reached the cluster size. The search for stable Si clusters is an important issue. In this work, the electronic structures and stability mechanism of the W@Si12 cluster are calculated by the first-principle calculations. Different from a C2v hexacapped trigonal prism structure of Si12, the W@Si12 cluster presents an embedded hexagonal prism structure with D6h symmetry. The addition of W atom leads to a higher stability. The molecular orbitals show obvious superatomic characteristics for the W@Si12 cluster, and their energy levels are more degenerate than that of the Si12 cluster. The population analysis indicates that a total charge of 2.21e is transferred from Si atoms to the center W atom, which suggests an ionic bond for W-Si. The electron localization function further proves a covalent bond for Si–Si. The enhanced stability of the W@Si12 cluster is attributed to the combination of the ionic and covalent bonds. [ABSTRACT FROM AUTHOR]

This article presents a streamlined approach to drawing Lewis structures that begins by constructing a trial structure that adheres to the valence states of the outer atoms, with any molecular charge (if present) placed on the central atom. The subsequent step adjusts bond and lone pairs to fulfill an octet configuration for the central atom if its electron count deviates from 8. This method facilitates the automatic generation of formal charges, eliminating the need for additional calculations typically required in other approaches that start with determining the total number of valence electrons. By focusing on valence configurations to construct Lewis structures, this method reduces the potential for errors associated with miscalculations. [ABSTRACT FROM AUTHOR]

The development of rational acid–base bifunctional heterogeneous catalysts for organic transformation reactions is a challenging procedure. An imidazolium sulfonic acid chloride ionic liquid immobilized NiS doped graphitic carbon nitride (NiS-gC3N4-IL) catalyst that is very effective, non-toxic, inexpensive, and capable of both acid and base reactions has been prepared. As prepared NiS-gC3N4-IL catalyst has a high catalytic potential for the Knoevenagel condensation reaction. In addition to the basic nature of the NiS-gC3N4-IL catalyst due to the existence of N-containing moieties, the acidic nature of the catalyst is also contributed by –SO3H groups of ionic liquid. These properties make this catalyst function as both acid as well as a base catalyst. The structural and morphological properties of the synthesized catalyst were thoroughly explored. The polycrystallinity of the amorphous g-C3N4 was produced as a result of the functionalization of ionic liquid. The remarkable catalytic activity of the NiS-gC3N4-IL nanosheets is demonstrated by the high yields of the products in less time and at optimal temperatures. The NiS-gC3N4-IL catalyst is highly efficient towards Knoevenagel condensation of nitrobenzaldehyde with 98% yield using ethanol as solvent. In addition, the catalyst showed exceptional recyclability and reusability. The catalyst is environmentally friendly, and the process is sustainable. [ABSTRACT FROM AUTHOR]

2D materials are regarded as promising electrocatalysts for water splitting because of their advances in providing ample active sites and improving electrochemical reaction kinetics. 2D MoSe2 has a greater intrinsic electrical conductivity and lower Gibbs free energy for reactant adsorption. However, there is still room for improvement in the electrocatalytic performance of MoSe2 for high‐performance electrochemical water splitting devices. Herein, the in situ preparation of heterostructure made of covalently bonded MoSe2 and rGO is reported. The obtained electrocatalyst contains the aggregated 3D structured MoSe2 over rGO, which is covalently bonded together with more edge sites. The active edge sites of MoSe2/rGO are dynamically involved in the electrocatalytic activity while facilitating electron transfer. Hence, the MoSe2/rGO heterostructure requires a low cell voltage of 1.64 V to reach 100 mA cm−2 in water splitting with high reaction kinetics. The aggregated MoSe2 over rGO with more edge sites exposed by the 3D structure of MoSe2 and the interfacial covalent bond in between them provides a favorable electronic structure for the HER and OER with low overpotentials and high current densities and enhances the stability of the electrocatalyst. This work presents an attractive and cost‐effective electrocatalyst suitable for industrial‐scale hydrogen fuel production. [ABSTRACT FROM AUTHOR]

Coupling coloration refers to a dyeing method that forms azo chromophore in-situ on fiber through coupling reaction, where some electron-donating groups on fiber are served as coupling components, when treated with a diazonium salt. Since the generated azo chromophores connect to the fiber by covalent bonds, dyed fabrics through coupling coloration usually have excellent fastness. In this paper, a dyeing method involving a fiber modification process and a coupling coloration procedure was proposed for cotton fabric. To achieve this goal, an aniline modifier was firstly designed and synthesized through combination of aniline and triazine structures. Chemical modification of cotton fabric using the aniline modifier successfully grafted aniline units onto cotton fiber. The modified cotton fiber was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and X-ray diffraction. Coupling coloration of the modified cotton fabric utilizing 2,6-dichloro-4-nitroaniline, p-nitroaniline or 2-amino-5-nitrothiazole diazonium salts successfully presented deep shades of orange, red or blue color, respectively, with good levelness property. The dyed fabric exhibited good color firmness property. For example, the dyed fabric showed good resistance to organic solvent extraction with color fixation values of higher than 90%. The color fastnesses to soaping and rubbing of the dyed cotton fabrics reached higher than grade 4. The dyed cotton fabrics also had excellent washing stability after 20 washing cycles. Besides, the migration values of the cotton fabrics through coupling coloration were lower than 3%, indicating excellent anti-migration property. [ABSTRACT FROM AUTHOR]

Abstract 2D materials are regarded as promising electrocatalysts for water splitting because of their advances in providing ample active sites and improving electrochemical reaction kinetics. 2D MoSe2 has a greater intrinsic electrical conductivity and lower Gibbs free energy for reactant adsorption. However, there is still room for improvement in the electrocatalytic performance of MoSe2 for high‐performance electrochemical water splitting devices. Herein, the in situ preparation of heterostructure made of covalently bonded MoSe2 and rGO is reported. The obtained electrocatalyst contains the aggregated 3D structured MoSe2 over rGO, which is covalently bonded together with more edge sites. The active edge sites of MoSe2/rGO are dynamically involved in the electrocatalytic activity while facilitating electron transfer. Hence, the MoSe2/rGO heterostructure requires a low cell voltage of 1.64 V to reach 100 mA cm−2 in water splitting with high reaction kinetics. The aggregated MoSe2 over rGO with more edge sites exposed by the 3D structure of MoSe2 and the interfacial covalent bond in between them provides a favorable electronic structure for the HER and OER with low overpotentials and high current densities and enhances the stability of the electrocatalyst. This work presents an attractive and cost‐effective electrocatalyst suitable for industrial‐scale hydrogen fuel production.

Abstract Value‐added conversion of lignocellulose is a sustainable approach. Photo‐refining biomass is in line with current environmental protection strategies. However, photo‐reforming biomass suffers from poor catalyst stability and low conversion efficiency. Here, we designed fructose as a lignocellulosic model. The heterogeneous structure of Prussian blue coating was constructed with a special covalent bond structure of CoCNZn. This structure has a catalytic conversion mechanism that can accelerate electron transfer. Fructose was simultaneously converted to value‐added platform compounds (5‐HMF and formic acid) and gaseous fuels (CO, CH4) with a conversion rate of up to 92.5%, which is more than 1.7 times than that of catalysts without adding Prussian blue. Hydrogen transfer and carbon transfer on the carbon atoms of fructose facilitates the production and accelerates the spillover of CO from formic acid. This work provides new ideas for the development of Prussian blue catalysts and the conversion of pentose.

The unique fundamental force related to chemical bonds, hydrogen bonds, and van der Waals interactions is the electromagnetic force, where the electrostatic force plays the major role. But, to our knowledge, no paper so far has explored the use of the electrostatic force explicitly to account for any molecular property (boiling point, solubility, etc.), except for the book Introductory Organic Chemistry and Hydrocarbons.1 This work uses the electrostatic force applied to chemistry to explain some molecular properties in organic chemistry. It also evaluates the understanding of Brazilian undergraduate students with respect to some topics of organic chemistry based on the electrostatic force. One questionnaire was applied to chemistry undergraduate students about Coulomb’s law and its application to organic chemistry, and the results indicate that most undergraduate students understand the electrostatic force equation applied to chemical education.

Post-translational modifications (PTMs) are crucial regulatory mechanisms that alter the properties of a protein by covalently attaching a modified chemical group to some of its amino acid residues. PTMs modulate essential physiological processes such as signal transduction, metabolism, protein localization, and turnover and have clinical relevance in cancer and age-related pathologies. Majority of proteins undergo post-translational modifications, irrespective of their occurrence in or after protein biosynthesis. Post-translational modifications link to amino acid termini or side chains, causing the protein backbone to get cleaved, spliced, or cyclized, to name a few. These chemical modifications expand the diversity of the proteome and regulate protein activity, structure, locations, functions, and protein-protein interactions (PPIs). This ability to modify the physical and chemical properties and functions of proteins render PTMs vital. To date, over 200 different protein modifications have been reported, owing to advanced detection technologies. Some of these modifications include phosphorylation, glycosylation, methylation, acetylation, and ubiquitination. Here, we discuss about the existing as well as some novel post-translational protein modifications, with their implications in aberrant states, which will help us better understand the modified sites in different proteins and the effect of PTMs on protein functions in core biological processes and progression in cancer. [ABSTRACT FROM AUTHOR]

Post-translational modifications (PTMs) are crucial regulatory mechanisms that alter the properties of a protein by covalently attaching a modified chemical group to some of its amino acid residues. PTMs modulate essential physiological processes such as signal transduction, metabolism, protein localization, and turnover and have clinical relevance in cancer and age-related pathologies. Majority of proteins undergo post-translational modifications, irrespective of their occurrence in or after protein biosynthesis. Post-translational modifications link to amino acid termini or side chains, causing the protein backbone to get cleaved, spliced, or cyclized, to name a few. These chemical modifications expand the diversity of the proteome and regulate protein activity, structure, locations, functions, and protein-protein interactions (PPIs). This ability to modify the physical and chemical properties and functions of proteins render PTMs vital. To date, over 200 different protein modifications have been reported, owing to advanced detection technologies. Some of these modifications include phosphorylation, glycosylation, methylation, acetylation, and ubiquitination. Here, we discuss about the existing as well as some novel post-translational protein modifications, with their implications in aberrant states, which will help us better understand the modified sites in different proteins and the effect of PTMs on protein functions in core biological processes and progression in cancer.

Due to their high conductivity and unique surface chemical characteristics, MXene and reduced graphene oxide (rGO) have received a great deal of attention in the field of electromagnetic wave absorption (EMA). This study describes the covalent modification of rGO with amino-functionalized MXene to create an electromagnetic absorbent material called MXene-rGO composite. After amidation, an amide bond successfully assembles MXene and rGO. The absorber performs admirably when the mass ratio of MXene to rGO is 1:2 (sample MG-3). With a thickness of 2.7 mm, the best reflection loss (RL) is −47.98 dB at 6.4 GHz. Additionally, the best effective absorption bandwidth (EAB) (RL< −10 dB) is 4.08 GHz (11.84–15.92 GHz) with a 1.4 mm matching thickness. The performance of the EMA can be obtained by adjusting the dielectric parameters and the migration rate of the electrons using the covalent bond as a stable carrier channel. The high dielectric loss, superior impedance matching, and strong attenuation ability contribute to the great absorption performance. [ABSTRACT FROM AUTHOR]

The possibility to monitor peptide and protein aggregation is of paramount importance in the so-called conformational diseases, as the understanding of many physiological pathways, as well as pathological processes involved in the development of such diseases, depends very much on the actual possibility to monitor biomolecule oligomeric distribution and aggregation. In this work, we report a novel experimental method to monitor protein aggregation, based on the change of the fluorescent properties of carbon dots upon protein binding. The results obtained in the case of insulin with this newly proposed experimental approach are compared with those obtained with other common experimental techniques normally used for the same purpose (circular dichroism, DLS, PICUP and ThT fluorescence). The greatest advantage of the hereby presented methodology over all the other experimental methods considered is the possibility to monitor the initial stages of insulin aggregation under the different experimental conditions sampled and the absence of possible disturbances and/or molecular probes during the aggregation process. [ABSTRACT FROM AUTHOR]

Conventional dyeing of cellulose with reactive dyes requires the use of huge quantities of electrolytes and alkalis and the temperature between 60–90°C. Using the above conditions a stable covalent bond is formed between the reactive group of the dye and the hydroxyl group of cellulose. Cationization of cellulose allows to carry out reactive dyeing without electrolytes and alkalis even at room temperature. The dye, depending on the cationic modifier used, can form only ionic bond between sulfonic group of the dye and quaternary group of the modifier or also covalent bond between reactive group of the dye and hydroxyl group of the modifier. In this work we investigate how light fastness is affected by the type of bond with which the dye bound to the cationized cellulose. So far, such research has not been published. We found that the light fastness of the reactive dyeings on cationized cellulose was lower compared to non-cationized cellulose and depends on the kind of modifier used: chlorocholine chloride, 3-chloro-2-hydroxy-propyltrimethylammonium chloride and copolymer [(chloro-methyl)oxirane +1 H-Imidazole]. Density electron changes of ionic bonds between quaternary group of modified cellulose and sulfonic group of reactive dyes were analyzed in relation to the fading process.

Conventional dyeing of cellulose with reactive dyes requires the use of huge quantities of electrolytes and alkalis and the temperature between 60–90°C. Using the above conditions a stable covalent bond is formed between the reactive group of the dye and the hydroxyl group of cellulose. Cationization of cellulose allows to carry out reactive dyeing without electrolytes and alkalis even at room temperature. The dye, depending on the cationic modifier used, can form only ionic bond between sulfonic group of the dye and quaternary group of the modifier or also covalent bond between reactive group of the dye and hydroxyl group of the modifier. In this work we investigate how light fastness is affected by the type of bond with which the dye bound to the cationized cellulose. So far, such research has not been published. We found that the light fastness of the reactive dyeings on cationized cellulose was lower compared to non-cationized cellulose and depends on the kind of modifier used: chlorocholine chloride, 3-chloro-2-hydroxy-propyltrimethylammonium chloride and copolymer [(chloro-methyl)oxirane +1 H-Imidazole]. Density electron changes of ionic bonds between quaternary group of modified cellulose and sulfonic group of reactive dyes were analyzed in relation to the fading process. [ABSTRACT FROM AUTHOR]

The theory of generalized charges is an asymptotic approximation of quantum mechanics for interatomic forces. It is based on the model of multicomponent electron gas, which extends the Thomas–Fermi model of inhomogeneous electron gas to pair electronic states. The present research takes in consideration the participation of the field of generalized charges in interatomic bonds. Herein, the definition of generalized charges (GC) by means of the overlap integral of the wave functions of valence electrons is given, and properties of GC are found out. Equations are derived for the potential and length of a homopolar bond, and dependence of these parameters on the generalized charges is shown. The dissociation energy of a diatomic molecule is expressed in terms of the nuclear charges, the function and multiplicity of the covalent bond, the angular momentum, and the vibrational energy of the binding electrons. The parametrization rules are substantiated and an a priori calculation of the dissociation energy of diatomic homonuclear molecules is carried out against the electronic configuration of the bond electrons and the nuclear charge. The calculation results for homonuclear compounds of the elements of the first four rows of the periodic table are shown to be of satisfactory accuracy. [ABSTRACT FROM AUTHOR]

In this study we tried to analyse how future teachers of Ecole Normale Supérieure (ENS) school who are at the end of education have integrated the specifications of covalent bonds in the different bond orders in terms of symmetry, stability, length, localisation (in the case of structures of ethane, ethylene and acetylene) or delocalisation of electrons (case of benzene). The analysis of responses to a written questionnaire shows that the majority of students have only integrated some knowledge, which may be termed as procedural, on the structural elements of molecules such as stability and the length of bonds. Although possessing some conceptual knowledge, students tend to use an alternative way of reasoning arising from the mental representation that single and multiple bonds are independent entities: the single bond is a "σ bond" while the double bond is considered only as a "π bond". [ABSTRACT FROM AUTHOR]

The important aspects of bonding are discussed in this perspective article, focusing on common misconceptions regarding 'covalent' and 'ionic' bonds. Special attention is given to the calculation of percentage covalent and ionic characters in a bond. In a course on chemical bonding, the graduate students were given an assignment: "Covalent versus ionic bonding in molecules." The outcome shows the majority of the students are unaware of the fact that no bond is purely ionic or covalent. To that end, a set of compounds are considered that are commonly used as examples of 'covalent' and 'ionic' compounds in standard textbooks, along with some 'partially covalent' noble gas (Ng) compounds containing noble coinage metals (M = Cu and Ag). State-of-the-art quantum chemical tools are utilized to analyze the bonding nature. The set contains alkali and alkaline earth metal halides, hydrogen halides, and main-group molecules like dihydrogen, dinitrogen, fluorine, chlorine, carbon monoxide, ammonia, and water, simple hydrocarbons, and noble gas- noble metal complexes. A perspective towards utilizing the most popular techniques in understanding the nature of bonding to eliminate certain common misconceptions among students including researchers, and a caution against the impetuous usage of the terms 'ionic' and 'covalent' to describe a bond. [ABSTRACT FROM AUTHOR]

Antimicrobial filtration materials based on essential oil components (EOCs) immobilized onto silicon oxide particles have been found effective for nonthermal stabilization of liquid foods (i.e., beer, juice, wine, and etc.). However, their antimicrobial efficiency depends on the food matrix. The present work aimed to assess the effect of the major constituents of liquid food matrices on the antimicrobial activity of vanillin immobilized onto silica microparticles. Silicon oxide particles were functionalized with vanillin and characterized. The maximum tolerated concentrations of different food major constituents (i.e., proteins, lipids, carbohydrates, organic acids, alcohols and minerals) were determined against Escherichia coli K12. The results showed that organic acid and alcohol had synergetic effects on vanillin-functionalized particles, and the addition of proteins, lipids or some carbohydrates inhibited their antimicrobial activity. No effects on microbial counts were found for mineral salts. The dual combinations between the synergistic and nonsynergistic food constituents showed improved antimicrobial activity compared to single compounds. The data confirmed previous in vitro experiments and could be used to predict the antimicrobial activity of the filtration system when treating real liquid food matrices. • Silica particles functionalized with vanillin are effective against E. coli • The in vivo antimicrobial efficiency depends on the food matrix. • Proteins, lipids, and pectin negatively impact on the antimicrobial activity. • Results might be used in the antimicrobial activity prediction of on other food matrices. [ABSTRACT FROM AUTHOR]

Macro-assembled graphene-based films can been considered as a potential material for the electromagnetic shielding (EMI) and thermal management in portable electronics. Here, a carbon nanotubes and graphene composite film with covalent bond (CNT-gGF) was fabricated through graphitized welding. The fabricated covalent-bonding CNT-gGF was featured with sandwich structure based carbon nanotubes welding graphene layers as the skeleton, resulting in an excellent conductivity of 13000 S cm−1 exceeding the pure graphene film. These unique structures endow CNT-gGF film with a prominent mechanical property and flexibility (folding resistant with 1000 cycles). Importantly, an outstanding EMI value is over 55 dB with a thickness of merely 20 μm in the broad frequency of 5–22 GHz. And the CNT-gGF was proven to exhibit a steady EMI property in a variety of extreme environments including high and low temperatures and burns. Moreover, the thermal conductivity of CNT-gGF could be up to 912 W m−1 K−1, then CNT-gGF presents well heat dissipation application for different voltages and mobile phone. Therefore, this large-size CNT-gGF film has a good application potential for high-performance EMI and thermal management, and this study provides favorable guidelines for the graphene-based films toward extreme demands in wearable electronics and 5G communication. A sandwich-structure composite carbon nanotubes-graphene (CNT-gGF) film with covalent bond was fabricated through graphitized welding. The fabricated CNT-gGF was featured with sandwich structure based CNT welding graphene layers as the skeleton, resulting in an excellent conductivity, super thermally conductivity and outstanding EMI shielding performance. [Display omitted] [ABSTRACT FROM AUTHOR]

The anomalous density–temperature relationship of vitreous silica with low hydroxyl content is explained by the formation of medium-range ordering structure in the glass transition process. The ordered medium-range structure has the shape of a “nanoflake” and consists of two layers of SiO4 tetrahedra, bonded by O atoms located in the middle of the structure. The nanoflakes interact with their surrounding structures through both covalent chemical bonds and van der Waals bonds. In the formation of the van der Waals bonds, the orientation of SiO4 tetrahedra can change, which results in an increase in distance between the nanoflakes and their surrounding structures. Thus, there is a slight volume enlargement associated with the formation of nanoflakes. Since the nanoflakes’ formation starts at a temperature near 1480 °C, and the population of the nanoflakes grows continuously as temperature decreases until about 950 °C, the bulk volume of silica glass increases in the temperature range from about 1480 °C to 950 °C. Therefore, the density anomaly of silica glass can be explained as a byproduct of forming of medium-range ordering structure in the silica glass transition.

[Display omitted] The possibility to design rational carbon dots surface functionalization for specific analytical and bioanalytical applications is hindered by the lack of a full knowledge of the surface chemical features driving fluorescent properties. In this model study, we have synthesized four different peptides, three of which are isobaric and not distinguishable by common MSMS experiments. After having characterized the peptides conformations by CD analyses, we have covalently bonded all four peptides to carbon dots by using different experimental procedures, which produce different functional groups on the carbon dots surface. The peptide orientations obtained on the differently functionalized surface of the nanoparticles were different and produced different fluorescent responses. The reported results indicate the possibility to design amino and carboxyl enriched surface carbon dots to answer specific chemical requirements, paving the way for the use of these nanoparticles as a versatile and useful new chemical and biochemical tool. [ABSTRACT FROM AUTHOR]

Phase‐change materials (PCMs) undergo a reversible transition from a semiconducting to a metallic state, nicely termed "incipient metal." This transition is driven by a Peierls distortion. A model of covalent bonding is developed in a tight‐binding scheme that accounts for the drastic evolution of some properties of PCMs, among which the Grüneisen parameter. The original vibrational properties of PCM and related Peierls distorted materials are analyzed. A three‐body covalent interaction describes the PCM properties. It explains the simultaneous softening of the optical phonons and the hardening of the acoustic phonons upon crystallization of the PCMs. [ABSTRACT FROM AUTHOR]

Understanding and exploring the existence of a recognizable boundary between the noncovalent tetrel bond (TtB) and the coordination or weakened covalent bond are important for the bonding characterization. We have developed a simple methodology for analysing the type of bonds based on comparison of the electrostatic and total static potentials along the bond line. For the typical σ-hole noncovalent bond formed by a Tt atom in a tetrahedral molecule, we have found that the space gap between positions of the maxima of the total static potential and the negative quantity of electrostatic potential is much wider than that for the coordination bonds in a trigonal bipyramid molecular system for the Cl-Tt/Cl…Tt and N-Tt/N…Tt (Tt = C, Si, Ge) bonds in molecules and molecular complexes. The distinction between the weakened covalent and strengthened noncovalent bonds is well reflected in behaviour of the Fermi hole along the bond line. Two-factor empirical rule based on the superposition of the electrostatic and total static potentials is suggested., (© 2024 Wiley‐VCH GmbH.)

Manipulating the properties of 2D materials through meticulously engineered artificial heterojunctions holds great promise for novel device applications. However, existing research on the crucial charge-transfer interactions and energy profile regulation is predominantly focused on 2D van der Waals structures formed via weak van der Waals forces, limiting regulatory efficiency at high costs. Herein, a refined atomic-molecular heterojunction strategy featuring strong covalent bonds between organic molecule and 2D violet phosphorus (VP) atomic crystal is developed, which enables enhanced charge-transfer dynamics and customizable band structure regulation at the molecular level. Both experimentally and theoretically, it is demonstrated that grafting efficiency, charge redistribution, and energy gap regulation critically depend on organic electronegativity, providing a low-cost yet high-efficiency regulatory effect on a large scale. As a proof of concept, the novel VP-molecular heterojunctions exhibit optimized performance in diverse application domains, presenting a general platform for future high-performance device applications., (© 2024 Wiley‐VCH GmbH.)

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Abstract As "molecular bridge," coupling agents can not only realize the covalent connection of composites, but also affect their properties, thus affecting the properties of devices based on them. Herein, leveraging differences in charge conduction properties of the (3‐aminopropyl)trimethoxysilane and 5,10,15,20‐tetrakis(4‐aminophenyl)‐21H,23H‐porphine caused by conjugacy structural differences, two kinds of layer‐by‐layer assembled smart carbon materials with different electrical properties are obtained at the same reduction temperature. The two graphene ultrathin films are then “planted” on Si/SiO2 substrates, respectively, as semiconductor layer and source/drain electrodes to fabricate an ultra‐stable all‐graphene field effect transistor (AG‐FET). Enabled by the covalent functionalized configuration and the functionally diverse of coupling agents, the AG‐FET obtained by this simple method won the high electrical characteristics, the hole, electron mobility, and the shelflife could reach 3.79 cm2/(V·s), 3.78 cm2/(V·s), and 18 months, respectively. In addition, good material stability and excellent device structure endow the device exceptional stability, electrical stability, and solvent resistance, improving its application prospect in solution phase sensing/detection. Such characteristics could be used to sense, transduce, and respond to external stimuli, especially in solution phase to monitor the important analytes, such as Hg2+ in a flowing sewage environment. We believe that such easy‐to‐manufacture AG‐FETs with ultrahigh performance and ultrahigh stability could also show great application prospects in other significant fields.

This research presents a near-infrared (NIR) light-activated drug delivery system designed to enhance the antimicrobial efficacy and bone integration of titanium-based implants. The system utilizes epoxy-modified TiO 2 nanotubes and CuS nanoparticles that generate reactive oxygen species (ROS) under 808 nm NIR light to enable controlled drug release. This innovative approach addresses the challenges of bacterial infection and fixation loosening and offers a significant improvement in implant performance. [Display omitted] • Enhanced antimicrobial efficacy and bone integration with NIR light-activated system. • Controlled drug release from CuS-modified TiO 2 nanotubes under 808 nm illumination. • Markedly improved antibacterial action and sustained release mechanism. Two primary obstacles impede the longevity of implants: bacterial infection and fixation loosening. This research introduces an innovative near-infrared (NIR) light-activated drug delivery system tailored to enhance the antimicrobial efficacy and bone integration of titanium-based implants. Titanium dioxide nanotube arrays (TNTs) were modified with epoxy for covalent bonding of therapeutic agents, and copper sulfide nanoparticles (CuS NPs) were added for regulated drug release. Alendronate sodium (ALN), an osteoporosis medication, was successfully bonded to the nanotubes. In vitro experiments showed that the release rate of ALN from TNTs-ALN reached 94 % within 36 h. In contrast, minimal release was observed in TNTs-ECH-ALN-CuS, which effectively addresses the prevalent issue of abrupt drug discharge typical in conventional delivery systems. In the context of NIR light exposure, the TNTs-ECH-ALN-CuS exhibited a notable ALN release efficacy of 48 %, demonstrating effective control over drug delivery. Additionally, the generation of ROS, coupled with temperature elevation under NIR exposure, endowed the modified TNTs with exceptional antibacterial efficacy, exceeding 99 % inhibition against E.coli and S.aureus. We observed a pronounced enhancement in the drug delivery mechanism, characterized by a reduction in the initial burst release and a sustained, controlled release, coupled with robust antibacterial action and notable biological performance. [ABSTRACT FROM AUTHOR]

Environmentally friendly and efficient solar-driven interfacial evaporation (SDIE) has been increasingly applied to seawater desalination, and the easy-to-operate electrospinning technology has attracted more and more attention. However, photothermal materials such as MXene are often combined with polymers suitable for spinning through ordinary blending. The inherent difficult dispersion of it may lead to the instability of spinning and decrease the performance of evaporators, further hindering their production and application. To address these challenges, this work designs a covalent bonding PVDF@MXene composite as the spinning raw material. Using the electrospinning technology, the high-efficiency membrane-based evaporator with well-dispersed internal materials and strong homogeneity is successfully fabricated. The membrane performance is optimal when the MXene content is 25 %, achieving an evaporation rate of 1.88 kg·m−2·h−1 and an efficiency of 94.06 % under one sun. Besides, it exhibits remarkable salt resistance, maintaining an evaporation rate of 1.81 kg·m−2·h−1 even at the salinity of up to 20 wt%. More importantly, the membrane can be immersed in oxidative reagents for 24 h without degradation or reduced performance, demonstrating its good environmental stability. Overall, this research not only provides a rational idea for addressing the dispersion issue of MXene, but also presents a potential solution to deal with the global freshwater shortage emergency. • PVDF@MXene composite linked by covalent bond was prepared for electrospinning. • The membranes with strong homogeneity were spun using electrospinning technique. • The membrane evaporation rate reached 1.88 kg·m−2·h−1 when its MXene content was 25 %. [ABSTRACT FROM AUTHOR]

Nature increases the functional diversity of the proteome through posttranslational modifications (PTMs); a process that involves the proteolytic processing or catalytic attachment of diverse functional groups onto proteins. These modifications modulate a host of biological activities and responses. Consequently, anomalous PTMs often correlate to a host of diseases, hence there is a need to detect these transformations, both qualitatively and quantitatively. One technique that has gained traction is the use of robust chemical strategies to label different PTMs. By utilizing the intrinsic chemical reactivity of the different chemical groups on the target amino acid residues, this strategy can facilitate the delineation of the overarching and inclusionary roles of these different modifications. Herein, we will discuss the current state of the art in post-translational modification analysis, with a direct focus on covalent chemical methods used for detecting them.

• Covalent bonds concn. in kerogen are 120–150 mmol/g, exhibiting a linear with H/C. • C al -C al /H bonds are two most abundant covalent bonds in kerogen. • Covalent bonds cleavage of kerogen basically follows first-order kinetics. • Covalent bonds that rupture at 300–420 °C (C B0) contains 40–70 % weak bonds. • The fraction of C B0 accounts for 5–9% of the total covalent bonds in kerogen. The rupture of covalent bond is regarded as the chemical essence of oil shale pyrolysis, while the variations in chemical structure of oil shale with different maturity are the primary factor influencing its pyrolysis behavior. That information, however, is scarce in the literature. In this study, the concentrations of covalent bonds in eight oil shale kerogens were calculated, and the variation of concentrations of eight covalent bonds with H/C in kerogens was summarized as well. Besides, the amount of covalent bonds rupture of eight kerogens during the pyrolysis at 300–420 °C were tested and calculated using 9,10-dihydrophenanthrene (DHP) as a probe molecule. The kinetics of bond cleavage reaction was analyzed, and the relationship between bond cleavage reaction and structure of kerogens was also studied. The results show that the concentrations of C al -C al and C ar -C ar bonds are 31.09–57.32 and 11.36–32.19 mmol/g, respectively. The concentrations of C al -C al and C al -H bonds of kerogen increase linearly with an increase of H/C, while the concentrations of C ar -C ar , C al -C ar and C ar -H bonds have a negative linear relationship with H/C. The amount of covalent bonds rupture of kerogens shows an increasing trend with an increase of pyrolysis temperature or time. The rate of bond cleavage decreases exponentially with the reaction time. The covalent bonds cleavage of kerogen basically follows first-order kinetics. The amount of the covalent bonds that can break at 300–420 °C in kerogens are 0.84–2.32, 2.12–4.43, 4.30–7.13, and 7.03–11.40 mmol/g, respectively. The covalent bonds that rupture of kerogens at 300–420 °C are not primarily C al -C al bond but weak bonds with bond energy lower than C al -C al bond, and the amount of weak bonds range from 4.53 to 10.42 mmol/g. These results extend the understanding on the mechanism of shale oil and chemicals in oil shale pyrolysis as well as that on the geological evolution of oil shale. [ABSTRACT FROM AUTHOR]

• Mn-doped FeNCN with larger lattice spacing enhance K+ intercalate/de-intercalate. • The enhanced charge transfer rate increases the reaction kinetics and storage capacity of K+. • Mn-doped FeNCN boasts a simple and scalable synthesis method. The development of anode materials with advanced structures to facilitate rapid charge transport and enhance potassium storage performance is urgently needed to propel the advancement of potassium ion batteries (PIBs). Transition metal carbodiimides have emerged as promising PIB electrode materials, but achieving high capacity and long-lasting cycling stability remains a challenging task. Here, Mn-doped FeNCN was synthesized by a one-step high-temperature solid-state reaction. Mn doping expands the lattice and boosts ionic conductivity, enabling favorable potassium ion storage and enhanced charging/discharging rates. In addition, density functional theory (DFT) calculations also prove that Mn-doped FeNCN facilitates the enhancement of potassium ions adsorption and promotes electron transfer. As a result, optimized Mn-FeNCN delivers high reversible capacity (402.6 mAh/g at 100 mA g−1) as PIBs anode. Even at high current density of 1000 mA g−1, it still delivers the reverse capacity of 301 mAh/g. This work provides a promising strategy to improve electrochemical performance of the transition metal carbodiimides. [ABSTRACT FROM AUTHOR]

SIRT1, an NAD+-dependent deacetylase, catalyzes the deacetylation of proteins coupled with the breakdown of NAD+ into nicotinamide and 2′-O-acetyl-ADP-ribose (OAADPr). Selective SIRT1 activators have potential clinical applications in atherosclerosis, acute renal injury, and Alzheimer's disease. Here, we found that the activity of the potent SIRT1 activator CWR is independent of the acetylated substrate. It adopts a novel mechanism to promote SIRT1 activity by covalently bonding to the anomeric C1′ carbon of the ribose ring in OAADPr. In addition, CWR is highly selective for SIRT1, with no effect on SIRT2, SIRT3, SIRT5, or SIRT6. The longer distance between the anomeric C1′ carbon of the ribose ring in OAADPr and Arg274 of SIRT1 (a conserved residue among sirtuins) than that between the anomeric C1′ carbon in OAADPr and the Arg of SIRT2, SIRT3, SIRT5, and SIRT6, should be responsible for the high selectivity of CWR for SIRT1. This was confirmed by site-directed mutagenesis of SIRT3. Consistent with the in vitro assays, the activator also reduced the acetylation levels of p53 in a concentration-dependent manner via SIRT1 in cells. Our study provides a new perspective for designing SIRT1 activators that does not rely on the chemical moiety immediately C-terminal to the acetyl-lysine of the substrate. [ABSTRACT FROM AUTHOR]

β-Glucosidase is widely used in several industrial segments, among which we can highlight the pharmaceutical industry, beverages, biofuels, animal feed production, and the textile industry. The great applicability of this enzyme, associated with the high cost of its production, justifies the need to find ways to make its use economically viable on an industrial scale. Through enzyme immobilization, the biocatalyst can be reused more than once, without great impact on its catalytic activity, and higher operational and storage stabilities can be achieved as compared to the free form. Accordingly, this review brings information about different techniques and supports that have been studied in the immobilization of cellulases with a focus on β-glucosidase, as well as the application of these immobilized systems to supplement commercial mixtures. [ABSTRACT FROM AUTHOR]

Although the many-body expansion (MBE) approach is widely applied to estimate the energy of large systems containing weak interactions, it is inapplicable to calculating the energies of covalent or metal clusters. In this work, we propose an interaction many-body expansion (IMBE) to calculate the energy of atomic clusters containing covalent bonds. In this approach, the energy of a system is expressed as the sum of the energy of atoms and the interaction energy between the atom and its surrounding atoms. The IMBE method is first applied to calculate the energies of nitrogen clusters, in which the interatomic interactions are truncated to four-body terms. The results show that the IMBE approach could significantly reduce the energy error for nitrogen clusters compared with the traditional MBE method. The weak size and structure dependence of the IMBE error with respect to DFT calculations indicates the IMBE method has good potential application in estimating energy of large covalent systems. [ABSTRACT FROM AUTHOR]

Introduction/purpose: Different types of interactions in diatomic molecules of complex atoms are analysed. Methods: The empirical formulas of Lennard-Jones, Buckingham, Buckingham-Corner, Morse, Danem, Gulbert-Hirschfelder, Klein and their combinations without their clear physical justification are used to take into account the repulsive and attractive forces in the molecule. To improve the situation of the binary interaction inside condensed matter, Gretchikhin and his associates proposed applying the Heitler-London quantum theory, but only at distances greater than equilibrium. At distances less than equilibrium between atoms in the binary interaction, the Lennard-Jones formula was still used. Using various kinds of fitting coefficients, in each case we obtained a match with the experimental data on the dissociation energy. A more general idea of all possible types of interactions was completely absent. In this connection, the need arose to reveal all possible types of interactions inside diatomic molecules and theoretically obtain dissociation energy, activation energy, and standard atomization enthalpy. The application of quantum mechanics methods in the Heitler-London theory allowed to take into account not only the Coulomb deterrence during exchange interaction, but also the Coulomb repulsion of nuclei. Results: The electric dipoles for neutral atoms and for positively charged ions of the core of diatomic molecules were calculated. This made it possible to calculate the electron-dipole and dipole-dipole interactions. A theory of the repulsion of positively charged nuclei of complex atoms in diatomic molecules has been developed. The interaction potentials for the molecules of carbon, nitrogen, oxygen, aluminum, silicon, and sodium are calculated. The developed physical model of the formation of diatomic molecules is compared with the empirical potentials of Lennard-Jones and Morse. At the internuclear distance equal to the sum of the energy radii of atoms in the molecule, a potential jump occurs with a transition from the negative to the positive region of binding energies, which determines the activation energy of the formation of diatomic molecules. Conclusion: From the obtained interaction potentials of atoms in diatomic molecules, the activation energy, ionization energy, standard atomization enthalpy, and electron affinity are determined. / Введение/цель: Проведен анализ разных типов взаимодействий в двухатомных молекулах из сложных атомов. Методы: Для учета сил отталкивания и притяжения в молекуле используются эмпирические формулы ЛеннардаДжонса, Бакингема, Бакингема-Корнера, Морзе, Данема, Гульберта-Гиршфельдера, Клейна и их комбинации без четкого физического обоснования. Улучшить ситуацию бинарного взаимодействия внутри конденсированных сред Гречихин и сотрудники предложили применить квантовую теорию Гайтлера-Лондона, но только на расстояниях больше равновесного. При расстояниях менее равновесного между атомами в бинарном взаимодействии по-прежнему использовалась формула Леннарда – Джонса. Применяя разного рода подгоночные коэффициенты, в каждом конкретном случае получали совпадение с экспериментальными данными по энергии диссоциации. Более общее представление о всех возможных типах взаимодействий полностью отсутствовало. В этой связи возникла необходимость выявить все возможные типы взаимодействий внутри двухатомных молекулах и теоретически получить энергию диссоциации, энергию активации, стандартную энтальпию атомизации. Применение методов квантовой механики позволило в теории ГайтлераЛондона учесть не только кулоновское сдерживание при обменном взаимодействии, но и кулоновское отталкивание ядер. Результаты: Проведен расчет электрических диполей у нейтральных атомов и у положительно заряженных ионов остова двухатомных молекул. Это позволило произвести расчет электрон-дипольного и диполь-дипольного взаимодействия. Разработана теория отталкивания положительно заряженных ядер сложных атомов в двухатомных молекулах. Выполнен расчет потенциалов взаимодействия для молекул углерода, азота, кислорода, алюминия, кремния и натрия. Проведено сравнение разработанной физической модели формирования двухатомных молекул с эмпирическими потенциалами Леннарда-Джонса и Морзе. На межъядерном расстоянии, равном сумме энергетических радиусов атомов в молекуле происходит скачок потенциала с переходом из отрицательной в положительную область энергий связи, что определяет энергию активации образования двухатомных молекул. Выводы: Из полученных потенциалов взаимодействия атомов в двухатомных молекулах определены энергия активации энергия ионизации, стандартная энтальпия атомизации и сродство к электрону. / Uvod/cilj: Analiziraju se različiti oblici interakcija u dvoatomskim molekulima složenih atoma. Metode: Koriste se empirijske formule Lenard-Džonsa, Bakingema, Bakingem-Kornera, Morzea, Danema, GilbertHiršfeldera, Klajna, kao i njihove kombinacije bez jasne realne opravdanosti, pri analizi odbojnih i privlačnih sila u molekulu. Za poboljšanje situacije binarne interakcije unutar zgusnute materije, Grečihin i njegovi saradnici su predložili primenu kvantne teorije Hajtlera i Londona, ali samo za razdaljine veće od ravnotežnog stanja. Lenard-Džonsova formula bila je korišćena i na razdaljinama manjim od ravnotežnog stanja između atoma u binarnim interakcijama. U svakom slučaju postigli smo poklapanje sa eksperimentalnim podacima o disocijaciji energije koristeći različite vrste odgovarajućih koeficijenata. Uopštenija ideja o svim mogućim tipovima interakcija potpuno je izostala. S tim u vezi, bilo je potrebno otkriti sve moguće tipove interakcija unutar dvoatomskih molekula i teoretski dobiti energiju disocijacije, energiju aktivacije i standardnu entalpiju atomizacije. Primena metoda kvantne mehanike u Hajtler-Londonovoj teoriji omogućila je da se uzme u obzir ne samo Kulonovo odbijanje tokom interakcije razmene već i Kulonovo odbijanje nukleusa. Rezultati: Izračunati su električni dipoli za neutralne atome i za pozitivno naelektrisane jone jezgara dvoatomskih molekula, što je omogućilo izračunavanje elektron-dipol interakcija, kao i dipol-dipol interakcija. Razvijena je teorija odbijanja pozitivno naelektrisanih nukleusa 9 složenih atoma u dvoatomskim molekulima. Izračunati su potencijali za molekule ugljenika, aluminijuma, silicijuma i natrijuma. Razvijeni fizički model formiranja dvoatomskih molekula upoređen je sa empirijskim potencijalima Lenard-Džonsa i Morzea. Na razdaljini između nukleusa, jednakoj zbiru energija prečnika atoma, u molekulu dolazi do skoka potencijala s prelazom od negativne do pozitivne oblasti energije vezivanja, što determiniše aktivacionu energiju formiranja dvoatomskih molekula. Zaključak: Iz dobijenih potencijala interakcija atoma u dvoatomskim molekulima određeni su energija aktivacije, energija jonizacije, standardna entalpija atomizacije, kao i afinitet prema elektronu.

The covalent inhibition mechanism of action, which overcomes competition with high-affinity, high-abundance substrates of challenging protein targets, can deliver effective chemical probes and drugs. Heat shock protein 72 (HSP72) expressed in cancer cells may be responsible for tumorigenesis and tumour progression by providing resistance to chemotherapy. In this study, we explore the most optimal binding mechanism in the inhibition of the HSP72 nucleotide-binding domain by two different covalent generation, TCI2 and TCI8. However, the structural basis and conformational changes associated with this preferential covalent inhibition to HSP72-TCI2 over HSP72-TCI8 remain unclear. Our results revealed that HSP72-TCI2 covalent complex was more able to stabilise and induce better interaction with high correlated dynamic motion of HSP72-NBD at ATP binding site throughout the simulation in comparison to the HSP72-TCI8 covalent complex. This is supported by the dynamic cross-correlation and principal component analysis that was more dominant in the HSP72-TCI2 inhibited complex. The insights demonstrating the above binding mechanism of HSP72 establish TCI2 covalent inhibition as the preferred method of inhibiting the HSP72 protein. This investigation aids in the understanding of the structural mechanism of HSP72 inhibition and would assist in the design of more potent covalent inhibitors of HSP72. [ABSTRACT FROM AUTHOR]

Covalently crosslinked 3D structures of carbon nanotubes (CNTs) and CNTs with low-layer graphene fragments (LGFs) are obtained via the hydrolysis of 3-aminopropyltriethoxysilane with oxidized CNTs and/or LGFs. The resulting samples are consolidated into non-disintegrating pellets through spark plasma sintering at 1100°C and 30 MPa. Oxygen-containing groups are eliminated, and the LGF particles are transformed into a mixture of graphene sheets and onion-like carbon nanostructures. The resulting CNT consolidates and mixtures of CNTs with LGF have densities of 0.85 and 0.81 g cm−3 and conductivities of 42 and 57 S m−1, respectively. It is shown that the consolidated samples can be oxidized with nitric acid vapor without disturbing their 3D structure. When oxidative exposure time is increased from 3 to 6 h, the content of oxygen grows from 8.4 to 15.3 at % for 3D-crosslinked CNT structures, and from 14.0 to 16.1 at % for 3D-crosslinked CNT structures with LGFs. [ABSTRACT FROM AUTHOR]

As "molecular bridge," coupling agents can not only realize the covalent connection of composites, but also affect their properties, thus affecting the properties of devices based on them. Herein, leveraging differences in charge conduction properties of the (3‐aminopropyl)trimethoxysilane and 5,10,15,20‐tetrakis(4‐aminophenyl)‐21H,23H‐porphine caused by conjugacy structural differences, two kinds of layer‐by‐layer assembled smart carbon materials with different electrical properties are obtained at the same reduction temperature. The two graphene ultrathin films are then "planted" on Si/SiO2 substrates, respectively, as semiconductor layer and source/drain electrodes to fabricate an ultra‐stable all‐graphene field effect transistor (AG‐FET). Enabled by the covalent functionalized configuration and the functionally diverse of coupling agents, the AG‐FET obtained by this simple method won the high electrical characteristics, the hole, electron mobility, and the shelflife could reach 3.79 cm2/(V·s), 3.78 cm2/(V·s), and 18 months, respectively. In addition, good material stability and excellent device structure endow the device exceptional stability, electrical stability, and solvent resistance, improving its application prospect in solution phase sensing/detection. Such characteristics could be used to sense, transduce, and respond to external stimuli, especially in solution phase to monitor the important analytes, such as Hg2+ in a flowing sewage environment. We believe that such easy‐to‐manufacture AG‐FETs with ultrahigh performance and ultrahigh stability could also show great application prospects in other significant fields. [ABSTRACT FROM AUTHOR]

The effect of gravity-driven sintering on the enhancement of ferroelectricity in lead-free piezoelectric ceramics was investigated. The (Ba 0.7 Sr 0.3)TiO 3 ceramics were fabricated using normal sintering and gravity-driven sintering. The ferroelectricity was investigated from polarization-electric field hysteresis loops, revealing that gravity-driven sintering led to an enhancement of ferroelectricity. Temperature-dependence of dielectric constant exhibited a shift of Curie temperature and improved maximum dielectric constant in the gravity-driven sintered ceramics. The crystal structure was investigated by structure refinement, resulting the tetragonal structure with expanded lattice constants and tetragonality in the gravity-driven sintered ceramics. The electron density distribution is indicated the stronger covalent bonding between Ti and O ions in the gravity-driven sintered ceramics due to lattice deformation by mechanical stress. The covalent bonding enhanced at 300 K was linked to the improved ferroelectricity. The structural changes induced by gravity-driven sintering played a crucial role in enhancing ferroelectricity, providing insights for the development of next-generation materials. [Display omitted] [ABSTRACT FROM AUTHOR]