Conductivity Measurements Research Articles

Crude oil-water emulsions formed by nozzle type inflow control device

Conventional water-in-oil emulsion studies where shear energy intensity and duration are applied to achieve ‘equilibrium’ emulsion droplet properties may not represent partial emulsion conditions observed in single pass flow through Inflow Control Device (ICD) orifices. Our experiments provide data expected to improve emulsion transport models for partial emulsification processes expected in well completion and production tubulars. Development of a novel flow adaptor apparatus is described together with a laboratory homogeniser enables independent control of shear intensity and duration together with input water volume fraction. The emulsions formed are characterised with a benchtop Nuclear Magnetic Resonance spectrometer for water content and droplet size, viscosity by a rotating bob viscometer and free water/emulsion proportion by optical photography. Experimental results confirmed partial emulsification above 30% V/V, as observed in both previous ICD flow experiments and field observations. Electrical conductivity measurements of the emulsions produced indicated that partial emulsification comprising an oil external emulsion phase together with free water, rather than emulsion inversion, occurs in this system.

Investigation of thermal, optical properties, AC conductivity and broadband dielectric spectroscopy of poly(ethyl methacrylate)/poly(vinyl chloride) polymer blend

This work reports the structural, thermal, optical and electrical properties of PEMA, PVC and their polyblends. These properties are investigated by FTIR, TGA, UV/Vis and broadband dielectric spectroscopy. FTIR spectra showed that the characteristic bands of PEMA and PVC are affected by blending and displayed red and blue shifts confirming that an intermolecular interaction between PEMA and PVC is occurred. Thermal degradation kinetics of PEMA, PVC and its polyblend samples is investigated in details and the thermal properties of each decomposition stage are estimated. UV measurements analysis revealed that Urbach energy (EU) is increased while optical bandgap decreased upon increasing the PVC content. The indirect and direct band gap (Eig/Edg) values are decreased from (3.95/4.21) to (3.10/3.92) eV. Also, upon increasing the content of PVC, the lattice dielectric constant (εL) is increased from 2.71 to 7.83. Wemple-DiDomenico model is applied for investigating the refractive index dispersion and to calculate the oscillator and dispersion energies. It is observed that the linear/nonlinear parameters are increased nonlinearly with increasing the PVC content. χ(1), χ(3) and n2 values are found to increase from 0.104, 0.213 × 10−13 and 4.01 × 10−12 to 0.363, 31.26 × 10−13 and 5.33 × 10−12. These results make PEMA/PVC polyblend strong candidates for use in the development and design of advanced optoelectronic devices. AC conductivity (σac) and dielectric measurements are carried out at various temperatures in wide frequency range. Jonscher power law is applied and showed that the predominant conduction mechanism in our samples is overlapping large-polaron tunneling (OLPT). The dielectric constant and electrical impedance are found to be frequency and temperature dependent. The investigation of the electric modulus (M*) revealed that M′ is increased non-linearly with increasing the frequency, while M″ spectra displayed two different modes of relaxation. The interfacial polarization (IP) is observed in low frequency region, while, dipolar relaxation is detected in high frequency region.

Atmospheric modulation of apparent electrical conductivity in a metal−organic framework

Combining high surface area and efficient charge transport, electrically conductive metal−organic frameworks (MOFs) find wide applications in energy storage, sensing, and electrocatalysis. Reliable characterization of electrical conductivity, the key metric for assessing this class of materials, remains challenging due to its high sensitivity to the atmosphere. Herein, through electrical characterization of an exemplary MOF, Cd2(TTFTB) (TTFTB4− = tetrathiafulvalene tetrabenzoate), under various controlled atmospheres, we show that adsorption of water in humid air or N2 improves the apparent room-temperature electrical conductivity by one to two orders of magnitude compared to the values observed in dry atmospheres. This observation in conjunction with spectroscopic characterization, structural analysis, and band structure calculations indicates significant contribution of water-mediated proton conductivity and/or proton-electron coupling to the apparent electrical conductivity. Thus, controlling and reporting atmospheres in electrical conductivity measurements of MOFs is critical to improve their reproducibility and to gain insights into electrical conduction mechanisms.

Thermal Performance Improvement of Composite Phase-Change Storage Material of Octanoic Acid–Tetradecanol by Modified Expanded Graphite

Phase-change cold storage technology is recommended as a solution for energy conservation and carbon neutrality in air conditioning systems of buildings. This study focuses on the development of binary composite phase-change materials comprising octanoic acid–tetradecanol (OA-TD). To enhance its thermal conductivity, expanded graphite (EG) was employed as an additive carrier, and the surface modification of EG particles using hexadecyltrimethoxysilane (HDTMOS) was attempted to make up for the instability and further to improve the performance of OA-TD/EG CPCMs. The OA-TD/EG-HDTMOS CPCMs were synthesized by EG mixed with EG-HDTMOS at a 1:1 mass ratio. The thermal performance and stability of the OA-TD/EG-HDTMOS CPCMs were thoroughly evaluated by multi-cycle melting–solidification and thermal conductivity measurements. The results revealed that the OA-TD mixture, when at a mass ratio of 77:23, exhibited a phase-transition temperature of 11.4 °C and a latent heat ranging from 150 to 155 J/g. Then, the OA-TD/EG-HDTMOS composite material, at a 12:1 mass ratio of OA-TD to EG-HDTMOS, solidified and melted at temperatures of 9.2 °C and 11.2 °C, with a latent heat ranging from 138 to 143 J/g, and significantly improved the thermal conductivity to 0.7 W/(m·K), representing a remarkable 133% increase compared to that of OA-TD alone. Even after undergoing 100 melting–solidification cycles, the OA-TD/EG-HDTMOS maintained superior phase-change thermal performance and stability, making it suitable for cold storage and energy conservation in air conditioning.

Thermophysical Profile of Industrial Graphene Water-Based Nanofluids.

The exceptional properties of high-grade graphene make it an ideal candidate for thermal dissipation and heat exchange in energy applications and nanofluid development. Here, we present a comprehensive study of few-layer graphene (FLG) nanofluids prepared in an industrial context. FLG nanofluids were synthesized through an ultrasound-assisted mechanical exfoliation process of graphite in water with a green solvent. This method produces FLG of high structural quality and stable nanofluids, as demonstrated by electron microscope, dynamic light scattering and ζeta potential analyses. Thermal conductivity measurements of FLG-based nanofluids were conducted in the temperature range of 283.15 K to 313.15 K, with FLG concentrations ranging from 0.005 to 0.200% in wt. The thermal conductivity of FLG nanofluids is up to 20% higher than water. The modeling of nanofluid thermal conductivity reveals that this enhancement is supported by the influence of the thermal resistance at the FLG interface, and the content, average dimensions and flatness of FLG sheets; this latter varying with the FLG concentration in the nanofluid. Additionally, the density and heat capacity of FLG suspensions were measured and compared with theoretical models, and the rheological behavior of FLG nanofluids was evaluated. This behavior is mainly Newtonian, with a weak 5% viscosity increase.

Enhancement of Thermoelectric Performance through Transport Properties Decorrelation in the Quaternary Pseudo-Hollandite Chalcogenide Rb0.2Ba0.4Cr5Se8.

The novel quaternary compound Rb0.2Ba0.4Cr5Se8 was synthesized and characterized in both single crystal and polycrystalline forms. Crystallizing in the monoclinic crystal system (space group C2/m, cell parameters a = 18.7071(4) Å, b = 3.6030(1) Å, c = 8.9637(3) Å, β = 104.494(2)°) and isostructural to pseudo-hollandite compounds, it features mixed Rb and Ba occupancy within its one-dimensional channels. High-temperature X-ray diffraction revealed no decomposition up to 973 K, and the thermal expansion coefficient at 300 K was determined to be 2.6(1)·10-5 K-1. Spin-polarized density functional theory (DFT) calculations showed that the density of states for Rb0.2Ba0.4Cr5Se8 is more polarized than that of Ba0.5Cr5Se8, resulting in a higher Seebeck coefficient, which was experimentally confirmed to reach a peak value of 400 μV·K-1 at 620 K. Resistivity measurements indicated a degenerate semiconducting behavior below 550 K, with a resistivity peak of 100 mΩ·cm at that temperature, leading to a maximum power factor of 0.21 mW·m-1·K-2. Thermal conductivity measurements indicated low values around 0.8 W·m-1·K-1 in the 300-900 K range, resulting in a thermoelectric figure of merit of 0.22 at 873 K. Decorrelated transport properties observed in this double-inserted pseudo-hollandite compound make Rb0.2Ba0.4Cr5Se8 a good example of beneficial synergistic effects for higher thermoelectric performance.

Investigating the synergistic antibacterial effects of chlorogenic and p-coumaric acids on Shigella dysenteriae

Chlorogenic acid (CGA) is a well-known plant secondary metabolite exhibiting multiple physiological functions. The present study focused on screening for synergistic antibacterial combinations containing CGA. The combination of CGA and p-coumaric acid (pCA) exhibited remarkably enhanced antibacterial activity compared to that when administering the treatment only. Scanning electron microscopy revealed that a low-dose combination treatment could disrupt the Shigella dysenteriae cell membrane. A comprehensive analysis using nucleic acid and protein leakage assay, conductivity measurements, and biofilm formation inhibition experiments revealed that co-treatment increased the cell permeability and inhibited the biofilm formation substantially. Further, the polyacrylamide protein- and agarose gel-electrophoresis indicated that the proteins and DNA genome of Shigella dysenteriae severely degraded. Finally, the synergistic bactericidal effect was established for fresh-cut tomato preservation. This study demonstrates the remarkable potential of strategically selecting antibacterial agents with maximum synergistic effect and minimum dosage exhibiting excellent antibacterial activity in food preservation.

Data Analytics in Agriculture: Enhancing Decision-Making for Crop Yield Optimization and Sustainable Practices

Collaboration across the agriculture supply chain is essential to address the high-yield demand and sustainable practices amid global overpopulation. Limited resources, such as soil and water, are compromised by excessive chemical agents and nutrient use. The Internet of Things (IoT) and smart farming offer solutions by optimizing agent applications, data analysis, and farm monitoring. Evidence from numerous studies indicates that collaboration in the supply chain, including farmers, can improve efficiency and productivity, reduce costs, and enhance crop quality. This paper investigates the transformation of traditional agriculture into smart farming through the integration of IoT technology and community partnerships. It presents a case study focused on educating farm owners about advanced technologies to enhance decision-making, improve crop yields, and promote sustainability. Additionally, the paper highlights the role of data analytics in agriculture. Farmers in the southern region of Zagreb, Croatia, were trained on the use of sensors and yield monitoring. Small farms in that region face challenges in improving yields due to limited capacity and lack of entrepreneurial experience. The DMAIC methodology was employed to address these issues and measure relevant parameters. The paper also discusses consistent patterns between electrical conductivity (EC) measurements and potassium levels in soil. It explains the potential of estimating potassium concentrations based on EC readings, or vice versa. Leveraging EC as a proxy for potassium levels could offer a cost-effective means of assessing soil fertility and nutrient dynamics. Additionally, Principal Component Analysis (PCA) biplot analysis is presented, showing that pH values behaved independently. Understanding these dynamics enhances knowledge of soil variability and informs sustainable soil management practices.

Some New Aspects of Gold-Catalyzed Benzannulation Reaction

Introduction: The gold-catalyzed benzannulation reaction of oxo-alkynes with al-kenes or alkynes is one of the important and unique reactions in gold-catalyzed organic trans-formations. Methods: In this manuscript, many facets of this reaction have been discussed concerning reac-tivity and selectivity, along with a new self-benzannulation process. The scope of this chemistry was extended to construct a phenanthrene moiety. Results: In addition, a palladium-gold dual catalytic arylation of isobenzopyrylium salts using arene-diazonium salts as an aryl group source and a one-pot isoquinoline synthesis is reported for the first time. Conclusion: Moreover, a conductance measurement experiment was performed, which supports the formation of ionic species, most likely the isobenzopyrylium auric ate complex as an inter-mediate formed during the reaction process.

Synthesis, Structural Elucidation, Density Functional Theory Calculations, In Vitro Antimicrobial, Anti‐Inflammatory and Anticancer Activities of Novel Zn (II)‐Group Fourteen Heterobimetallic Complexes Derived From Schiff Base Ligand

ABSTRACTIn the present work, new heterobimetallic complexes with the general formula [Zn(C16H32N8)M2(R)4Cl2], where M = Sn (IV) and Si (IV) and R = ‐CH3 and ‐C6H5, were synthesized by reacting the methanolic solution of the monometallic complex [Zn(C16H36N8)Cl2] with group 14 organometallic dichloride [(CH3)2SnCl2/(C6H5)2SnCl2/(CH3)2SiCl2/(C6H5)2SiCl2]. The structures of the synthesized complexes were determined using several spectrometric techniques, including FT‐IR, 1H NMR, 13C NMR, 119Sn NMR, 29Si NMR, ESI‐MS, PXRD, and molar conductivity measurements. Density functional theory (DFT) calculations were carried out to investigate the quantum chemical characteristics of the newly synthesized Zn (II) complexes. The antimicrobial potential of the monometallic and heterobimetallic complexes was evaluated against two Gram‐positive bacteria (Bacillus subtilis and Bacillus cereus), two Gram‐negative bacteria (Xanthomonas campestris and Pseudomonas aeruginosa), and two fungal strains (Aspergillus flavus and Fusarium oxysporum) by the agar well diffusion method, with heterobimetallic complex [Zn(C16H32N8)Sn2(C6H5)4Cl2] as the most potent complex against microbes. The complex [Zn(C16H32N8)Sn2(C6H5)4Cl2] exhibited significant potential in inhibiting inflammation, demonstrating an IC50 value of 9.75 μg/mL, which closely rivals that of the standard drug sodium diclofenac (IC50 = 4.59 μg/mL). Furthermore, all the synthesized compounds were assessed for their anticancer potential against three cancer cell lines (HCT‐116, MCF‐7, and HeLa) by the MTT assay. The results indicated that the complex [Zn(C16H32N8)Sn2(C6H5)4Cl2] exhibited the most pronounced cytotoxic effects, with values of 4.25 ± 0.15 μM, 4.90 ± 0.18 μM, and 5.20 ± 0.24 μM observed for HCT‐116, MCF‐7, and HeLa cancer cell lines, respectively.

Comparison and evaluation of the cast iron castings surface using different types of foundries sands

This study investigates and compared various properties of high-quality foundry sands on the surface quality of castings, whose cores are produced using the col-box method. Methods such as the measurement of flushable fraction, sieve analysis, electron and optical microscopy, pH and electrical conductivity measurements were used to monitor the physico-chemical properties of silica and non-silica sands. 5 core mixtures were prepared from individual sands by adding 1.6 % of organic binder based on phenol-formaldehyde formed from resin and hardener using an MR100 mixer. The produced cores were placed in moulds made of a uniform bentonite mixture and cast (15 test castings). In all the tested sand samples, the dust content was visible at a 300× magnification, but the share of flushable content is not exceeded 3 %, which is one of the fundamental conditions for moulding. All the tested sands are heat resistant at 1600 °C and had a low flushable fraction in the range 0.05–0.3 %. The results indicate that the occurrence of surface defects in high-quality foundry sands is not related to the flushable fraction content, to the average grain size value d50, to the electrical conductivity, to the shape of the sand grains and to the flexural strength. The surface roughness is related to the average grain size, to the grain shape and to the flexural strength.

Bolometric detection of Josephson radiation.

One of the most promising approaches towards large-scale quantum computation uses devices based on many Josephson junctions. Yet, even today, open questions regarding the single junction remain unsolved, such as the detailed understanding of the quantum phase transitions, the coupling of the Josephson junction to the environment or how to improve the coherence of a superconducting qubit. Here we design and build an engineered on-chip reservoir connected to a Josephson junction that acts as an efficient bolometer for detecting the Josephson radiation under non-equilibrium, that is, biased conditions. The bolometer converts the a.c. Josephson current at microwave frequencies up to about 100 GHz into a temperature rise measured by d.c. thermometry. A circuit model based on realistic parameter values captures both the current-voltage characteristics and the measured power quantitatively. The present experiment demonstrates an efficient, wide-band, thermal detection scheme of microwave photons and provides a sensitive detector of Josephson dynamics beyond the standard conductance measurements.

Ruthenium-p-Cymene Complexes Incorporating Substituted Pyridine–Quinoline Ligands with –Br (Br-Qpy) and –Phenoxy (OH-Ph-Qpy) Groups for Cytotoxicity and Catalytic Transfer Hydrogenation Studies: Synthesis and Characterization

Organometallic ruthenium complexes with p-cymene = 1-methyl-4-(1-methylethyl)-benzene and N^N = bidentate polypyridyl ligands constitute interesting candidates with biological and catalytic properties. Towards this aim, we have synthesized four ruthenium(II)–arene complexes of the type [Ru(η6-p-cymene)(N^N)Cl][X] (N^N = Br-Qpy = 6-bromo-4-phenyl-2-pyridin-2-yl-quinoline, X = Cl− (1a); PF6− (1b); N^N = OH-Ph-Qpy = 4-(4-phenyl-2-(pyridin-2-yl)quinolin-6-yl)phenol, X = Cl− (2a); PF6− (2b)). This is the first report of ruthenium(II) p-cymene complexes incorporating substituted pyridine–quinoline ligands, with –Br and –C6H4OH groups in the 6-position of quinoline. We also refer to the cytotoxicity of the ligands and their possible effect of modulating the activity of the ruthenium(II) complexes. These were characterized by a combination of spectroscopic methods (ATR-IR, UV–Vis, multinuclear NMR), elemental analysis, and conductivity measurements. The solid-state structure of 2b, determined by single-crystal X-ray diffraction, reveals a three-legged piano-stool geometry. The in vitro cytotoxic activities of the new complexes were evaluated in HEK293T (human embryonic kidney cells) and in HeLa cells (cervical cancer cells), via the MTT assay. Poor in vitro anticancer activities were observed for the HeLa cancer cell line, with 2a being the most potent (IC50 = 75 μΜ). The cytotoxicity of Br-Qpy in HEK293T is comparable to that of cisplatin. Both complexes 1a and 1b successfully catalyze the transfer hydrogenation of benzophenone to benzhydrol by 2-propanol at 82 °C. The catalytic performance of 1a in the ratio of S:Cat:B = 400:1:40 (S = substrate, Cat = catalyst, B = base = KOiPr) leads to a conversion of 94%, within 3 h of reaction. Presumably, catalytic transformation takes place via ruthenium(II) hydride species being the active catalyst.

Optical, thermal, and electrical characteristics of cashew gum/Polypyrrole/zinc oxide nanocomposites for next‐gen optoelectronics

AbstractIn this electronic era, there is a demand to switch from conventional polymers to conducting biopolymers. We developed conducting biopolymer nanocomposites of cashew gum (CG) and polypyrrole (PPy) with zinc oxide (ZnO) nanofillers [CG/PPy/ZnO] via in‐situ oxidative polymerization using a sustainable solvent. These nanocomposites were characterized using Fourier‐transform infrared spectroscopy (FTIR), UV–visible spectroscopy, field emission scanning electron microscope (FE‐SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The FTIR signal at 855 cm−1 confirms the successful inclusion of ZnO nanofillers into the biopolymer. UV–vis absorption of the blend nanocomposite increases with the nanoparticle doses. Among the various blend nanocomposites, the least bandgap energy was observed for 7 wt% ZnO loading. FE‐SEM revealed homogeneous dispersion of ZnO nanofillers in the CG/PPy blend at 7 wt% ZnO. TGA and DSC demonstrated that the CG/PPy/ZnO nanocomposites have better thermal stability and glass transition temperature than the pure polymer blend, indicating enhanced thermal properties. The CG/PPy/7 wt% ZnO showed the highest conductivity, 4.62 times greater than the pristine blend at 100 Hz. Dielectric constant, activation energy, AC conductivity and dielectric loss measurements demonstrated that the nanocomposites outperformed the pure polymer blend. Complex impedance analysis revealed increased impedance with rising temperature. Overall, CG/PPy/ZnO nanocomposites exhibit superior optical, morphological, thermal, electrical, and dielectric properties, making them promising for energy storage and optoelectronic applications.Highlights Ecofriendly synthesis of CG/PPy/ZnO nanocomposites Enhancement in optical, structural, and thermal properties of CG/PPy/ZnO Dielectric properties and temperature‐dependent AC conductivity are summarized. Blend nanocomposite shows higher AC conductivity and dielectric constant CG/PPy/ZnO nanocomposites are suitable for energy storage applications

Self-assembly of mixed surfactants sodium dodecylsulfate and polyethylene glycol dodecyl ether in aqueous solutions

The thermodynamic behavior of mixed systems containing the anionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant polyethylene glycol dodecyl ether (Brij L4) in aqueous solutions was investigated. Electrical conductivity and interfacial tension measurements were employed to investigate the concentration-dependent properties of these surfactant mixtures. Two main experiments were conducted: i) constant ratio experiment: the overall surfactant concentration was varied while maintaining a fixed ratio between SDS and Brij L4. It was shown that the critical micelle concentration (CMC) determined from electrical conductivity measurements does not indicate the formation of the first mixed micelles as observed using tensiometry, but the point from which the adsorption of counterions by the existing micelles became important. By using the Regular Solution Theory (RST), it was found that the interaction between SDS and Brij L4 is synergistic, driven by dipole-ion interactions of the hydrophilic regions of the two surfactants. ii) Fixed SDS concentration while increase the Brij L4 concentration: the resulting electrical conductivity exhibited non-trivial behavior which complexity arose from simultaneous phenomena of incorporation of free SDS molecules into the micelles as Brij L4 concentration increased, leading to a decrease in electrical conductivity; liberation of some adsorbed counterions from the mixed micelles to the solution, which increases the conductivity and increase of viscosity due to Brij L4 further addition that leads to a sequential decrease in electrical conductivity.

The evolution of patch-clamp electrophysiology: robotic, multiplex, and dynamic.

The patch-clamp technique has been the gold standard for analysis of excitable cells. Since its development in the 1980s it has contributed immensely to our understanding of neurons, muscle cells, and cardiomyocytes, and the ion channels and receptors that reside within them. This technique, predicated on Ohm's law, enables precise measurements of macroscopic excitability patterns, and ionic and gating conductances that can be assessed even down to the single channel level. Over the years, patch-clamp electrophysiology has undergone extensive modifications, with the introduction of new applications that have enhanced its power and reach. The most recent evolution of this technique occurred with the introduction of robotic high throughput automated platforms that enable high quality simultaneous recordings, in both voltage- and current-clamp modes, from 10s to 100s of cells, including cells freshly isolated from their native tissues. Combined with new dynamic-clamp applications, these new methods provide increasingly powerful tools for studying the contributions of ion channels and receptors to electrogenesis. In this brief review, we provide an overview of these enhanced patch-clamp techniques, followed by some of the applications presently being pursued, and a perspective into the potential future of the patch-clamp method. Significance Statement The patch-clamp technique, introduced in the 1980s, has revolutionized understanding of electrogenesis. Predicated on Ohm's law, this approach facilitates exploration of ionic conductances, gating mechanisms of ion channels and receptors, and their roles in neuronal, muscular, and cardiac excitability. Robotic platforms for high-throughput patch-clamp, and dynamic-clamp, have recently expanded its reach. Here, we outline new advances in patch-clamp including high throughput analysis of freshly-isolated neurons, and discuss the increasingly powerful trajectory of new patch-clamp techniques.

Electron Transport over 2D Molecular Materials and Assemblies.

ConspectusTwo-dimensional (2D) molecular materials, in which the major interactions are confined in 2D planes with contrasted force fields acting in between the planes, have been key electronic functional materials since the past decade. Even without referring to the functionals of graphene-based systems, 2D electronic conjugated systems are expected to show extrawide dynamic ranges in electronic density of states (DOS) tuning, effective electron mass, electron mobility, and conductivity. A major advantage of 2D electronic systems is their compatibility with the ubiquitous electronic devices designed using planar structures, such as transistors and memories, which is associated with the utility of 2D active materials. The mobility of electrons in 2D systems is the key to their utility, and various conjugated molecular and 2D materials have been designed to optimize the mobility. This Account begins with an introduction for mobility assessment: using noncontact time-resolved microwave conductivity (TRMC) measurements as a technique to probe differential conductivity upon transient charge carrier injection into the materials. Electronic transport over 2D electronic materials such as graphenes, covalent organic frameworks (COFs), and metal-organic frameworks (MOFs) is discussed with a special emphasis on molecular building blocks, fine-tuning conducting species and linkages, topology of the framework, and controlling molecular doping. The superiority of β-ketoenamine-linked COF over imine-linked COF films in charge transport and dominant in-plane charge carrier mobility over out-of-plane mobility is also illustrated. Systematic molecular engineering of the building blocks of β-ketoenamine-linked COFs with varying degrees of donor-acceptor (D-A) conjugation, torsional angles, and reaction conditions resulted in the modulation of the efficiency of charge carrier generation/transport as well as exciton migration. The advantages of 2D systems are finally discussed in terms of the mobility interplaying with spatial arrangements of molecules as well as the substantial role of intermolecular interactions in stabilizing their condensed phases. The strong correlation between the dispersion of mobility and hierarchical intermolecular interactions sheds light on the way to overcome structural fluctuation on the optimization of charge transport in molecular electronic materials. The point of singularity in the dispersion at an intermolecular distance of d ∼ 0.3 nm is deduced from the overall mobility assessment in condensed phases of conjugated molecules, suggesting key roles of intermolecular electronic coupling: the new concept of electronic conjugation. Exceptional electronic coupling with relatively high charge carrier mobility was also observed, particularly in 2D spatial arrangements of chiral molecules in contrast to 3D analogues, where the reduction of gravitational density of the molecular condensates was impacting DOS: the Wallach's rule. 2D electronic systems are strong candidates for the violation of the long-lasting Wallach's rule in terms of DOS.

Nanocomposites based on MWCNT and nanoclay: Effect of acrylated epoxidized soybean oil on curing and composite properties

UV and thermal-curing hybrid epoxy adhesives are generally developed with a combination of epoxy acrylates and thermal-curing epoxy resin. This study modified bisphenol-A type epoxy resin (ER) with acrylated epoxidized industrial crop soybean oil (AESO) to obtain a dual-curable epoxy system. Hydroxylated multi-walled carbon nanotube (MWCNTOH) and montmorillonite-type nanoclay (NC) first was used as nano reinforcement in this system. Both thermal and UV-curing were applied to composites. Tensile and hardness tests, thermogravimetric analysis (TGA), and four-point probe electrical conductivity measurements were used for the nanocomposite characterization. Although (UV+thermal) curing increased the thermal strength of the nanocomposites, it caused a decrease in their electrical conductivity and moisture absorption. The highest tensile strength values were obtained as 107 MPa and 97 MPa for thermally cured 1.5 wt% MWCNTOH and 2 wt% NC composites, respectively. The effect of the AESO ratio on UV curing of nanocomposites was investigated and 10 % was found to be the most suitable. MWCNTOH composites also exhibited the highest electrical conductivity with a percolation threshold of 1.5 wt%. The effect of hydrothermal aging on thermal and electrical conductivity properties showed that only T5 and T10 values of thermally or (UV+thermally) cured MWCNTOH and NC composites decreased, T50 values did not change significantly.

Exploring the Microbial Inhibition Ability of Newly Synthesized Diorganotin(IV) Complexes of Hydrazone Ligands: Structural Elucidation, Crystal Structure, and DFT Studies

ABSTRACTIn our work, we have successfully synthesized twelve diorganotin(IV) complexes (4–15) from different hydrazone ligands and diorganotin(IV) dichlorides. The complexes have a general formula [R2SnL1–3], where R = Et, Me, Bu, and Ph groups. The hydrazone ligands (1–3) were synthesized through a condensation reaction involving 3‐ethoxysalicylaldehyde with different benzhydrazide derivatives. All the synthesized hydrazone ligands and their complexes underwent screening by employing numerous spectroscopic and physicochemical techniques, such as molar conductance measurements, mass spectrometry, (1H, 119Sn, and 13C) NMR, SEM‐EDAX, and FT‐IR. Spectroscopic analysis revealed that the hydrazone ligands were attached to tin atoms in a tridentate fashion via ONO donor atoms, suggesting a pentacoordinated geometry for the complexes. Furthermore, the X‐ray crystallography analysis for Complex 6 revealed the distorted square pyramidal geometry around the tin atom. Moreover, a DFT study was also carried out for Ligand 3 and its complexes (12–15) by employing B3LYP/LanL2DZ theory level (Gaussian 9 software package) to obtain the optimized geometry and global reactivity descriptors, structural behavior, and their efficacy against different microbes. To assess the biological efficacy of synthesized compounds, an in vitro antimicrobial assay was conducted against different fungal (Aspergillus niger and Candida albicans) and bacterial (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa) strains. The results of the antimicrobial assay demonstrated that Complexes 7, 11, and 15 depicted better results against E. coli strain and C. albicans strain, implying that the higher lipophilic character of these complexes facilitates their easy passage through the cell membrane of microbes. Furthermore, an ADMET study was carried out to evaluate the toxicity score of synthesized compounds.

Semiconductive Potassium Hydroxamate Coordination Polymers with Dual Charge Transport Paths Originating from the π-π Stacking Columns.

Semiconductive coordination polymers (CPs) have recently garnered a significant amount of attention due to their widespread application in many areas. The "through-space" approach has emerged as the most versatile strategy for constructing semiconductive CPs. However, this approach often leads to the formation of unidirectional charge transport paths, resulting in anisotropic electrically conductive performance and low average conductivities in pressed pellets, thus presenting significant challenges for the practical application of semiconductive CPs. Consequently, there is a strong desire to explore simpler and more versatile strategies for designing semiconductive CPs with dual or multiple charge transport paths. Herein, we report on two semiconductive potassium hydroxamate coordination polymers, denoted as [K(HONDI)(H2O)2]n (1) and [K(HONDI)]n (2). Both compounds theoretically possess dual charge transport paths, occurring internally and externally within the π-π stacking columns of the ligands. Conductivity measurements revealed that compounds 1 and 2 both exhibit semiconductive properties, with their electrical conductivities reaching 2.3 × 10-6 and 1.9 × 10-7 S/cm, respectively, at 30 °C. Their electrically conductive performance could be attributed to theoretically biaxial "band-like" charge transport inside crystals and "hopping" charge transport between grain boundaries.