Vitaly V. Chaban

Residual corrosion inhibitor (RCI) monitoring is essential for ensuring the effectiveness of corrosion mitigation programs in oil and gas production systems. Among the available analytical techniques, Fourier transform infrared spectroscopy (FTIR) offers advantages such as rapid analysis, minimal sample preparation, and the absence of chemical reagents. In this study, an FTIR-based method was developed for the quantification of 2-phenyl-2-imidazoline (IMDZ), a corrosion inhibitor, and the influence of typical produced-water constituents on its spectroscopic response was investigated. Calibration curves were constructed using IMDZ concentrations ranging from 100 to 1000 ppm in Milli-Q water. Two characteristic spectral regions were evaluated, centered at approximately 1500 and 784 cm–1. The band at 1500 cm–1 exhibited a linear response with concentration (R2 = 0.9922), while the band at 784 cm–1 showed a logarithmic response. The estimated limit of detection (LOD) and limit of quantification (LOQ) for the 1500 cm–1 band based on within-pellet repeatability were approximately 32 and 96 ppm, respectively. The effects of acetic acid, NaCl, CaCl2, FeCl2, NaHCO3, and dissolved CO2 were evaluated individually at a fixed IMDZ concentration of 500 ppm. Significant matrix effects were observed, particularly in the low-frequency spectral region. Acetic acid and FeCl2 produced the largest spectral perturbations, whereas NaCl caused substantial reductions in peak area. Overall, the 1500 cm–1 band exhibited greater resistance to interference than the 784 cm–1 band. Quantum-chemical calculations revealed strong hydrogen-bond formation between IMDZ and acetic acid, as well as cation−π interactions involving dissolved metal cations. The combined experimental and computational results demonstrate that the spectral region centered at approximately 1500 cm–1 is the most suitable analytical marker for FTIR-based quantification of IMDZ in brine environments.

We discuss a systematic investigation into the liquid/vapor equilibria and interfacial properties of a homologous series of dialkyl carbonates (DACs), specifically dimethyl carbonate (D1C), diethyl carbonate (D2C), dipropyl carbonate (D3C), and dibutyl carbonate (D4C), using classical molecular dynamics simulations (CMDs). Simulations were performed over a temperature range of 350–450 K to elucidate the impact of alkyl chain length on the thermodynamic, liquid/vapor, and transport properties. Our results demonstrate that saturated vapor pressures decrease uniformly with increasing alkyl chain length, ranging from 6.0 bar for D1C to 0.56 bar for D4C at 450 K. Smooth adjustment of DAC volatility is useful to offer the most suitable solvent and conditions. Specific liquid densities decreased with both increasing temperature and chain length, with D1C exhibiting the highest thermal expansivity, 2.2 × 10 ⁻³ 1/K. Translational dynamics reveal a strong temperature dependence and a systematic decrease in molecular mobility as the chain length grows. Electrostatic interactions dominate the structural and dynamical properties of DACs, thanks to large partial charges on the headgroup. The rendered results are of fundamental importance to understand DACs at elevated temperatures.

Electrolytes are pivotal components of Li-ion batteries. Electrolytes enable ion transport between electrodes. The chemical composition and thermodynamic phase of an electrolyte directly influence performance, safety, and longevity. This chapter discusses challenges and advancements in liquid and solid electrolytes with an accent on their roles in shaping next-generation energy storage systems. Liquid electrolytes, composed of lithium salts dissolved in organic solvents remain the present industry standard, thanks to their desirable ionic conductivity and mature manufacturing infrastructure. Flammability, toxicity, and chemical reactivity under extreme conditions pose risks, such as thermal runaway and fire hazards. In turn, solid electrolytes offer non-flammable alternatives. They exhibit enhanced thermal stability and compatibility with highly energy-dense anodes like lithium metal. Ceramic electrolytes boast promising conductivity and electrochemical stability. Thus far, high production costs and processing challenges hinder the scalability of ceramic alternatives. Polymeric Li-ion electrolytes are flexible and easy to process, yet face limitations, such as relatively low ionic conductivity. Liquid Li-ion electrolytes dominate due to established supply chains and cost-effectiveness. Alternatively, solid electrolytes steadily gain traction amid modern demand for safer and higher-capacity batteries. The synthesis of solid Li-ion electrolytes involves costly processes and requires rare materials. Safety represents a critical driver for solid electrolytes, as they eliminate flammability risks and mitigate lithium dendrite formation. Sustainability and recyclability limitations are common challenges across both electrolyte types. Ionic liquids dissolving lithium salts can be considered to represent the third type of Li-ion electrolyte due to their non-volatility and broad voltage tolerance. Liquid Li-ion electrolytes contribute harshly to environmental pollution due to toxic solvent leakage, whereas solid electrolytes face obvious hurdles in material recovery. Compatibility with electrode materials and electrochemical stability windows dictate electrolyte selection. Herein, we underscore the need for interdisciplinary innovation to balance performance and safety in electrolyte design for a decarbonized future.

During long-term operation, polypropylene (PP) films in metalized capacitors endure continuous thermal stress from dielectric losses. This persistent thermal exposure gradually degrades the molecular structure of PP and compromises its electrical endurance. Internal pressure evolves due to gas accumulation from polymer degradation. Reactive molecular dynamics (RMD) simulations reveal that pressure elevation suppresses PP chain scission. Increasing pressure from 0.75 GPa to 1.0 GPa reduces the number of molecular fragments by 20 %. Under 2.0 GPa, overall 16 molecules survive compared to 86 at 0.75 GPa. Restricted molecular mobility is linked to suppressed decomposition in RMD. Reduced free volume limits conformational motion of PP. Specific gaseous environments alter PP ageing kinetics. Methane promotes extensive fragmentation. Methane is a by-product of PP chain scission. Slight differences in molecular polarities correlate with gas impacts on PP accelerated ageing. The new reported findings shed light on molecular mechanisms of PP ageing in relevant environments.

The present study investigates the potential of dicationic ionic liquids (DILs) and monocationic ionic liquids (MoIL), with and without metal in the anion, for CO₂ capture applications. The structures of the samples were confirmed by FTIR, ¹H NMR spectroscopy, and Raman spectroscopy, while their physicochemical properties, density, viscosity, and thermal stability were evaluated. A series of computational simulations were conducted by using density functional theory (M11/def2-TZVP) to ascertain the multiplicity of the ground state of the magnetic anion [FeCl₄]^-. These simulations determined the multiplicity to be a sextet and furthermore identified the trans conformation as the most energetically favorable for cation [E(MIM)₂]²⁺. This finding demonstrates a correlation between the structural conformations and the experimental Raman spectra. The findings of CO₂ sorption and kinetic tests, conducted under postcombustion conditions (40 °C, 4 bar), indicated that DILs exhibited superior performance in comparison to MoILs. The DIL [E(MIM)₂][2Cl] exhibited the highest sorption capacity (110.20 μmol/g), which is almost three times higher than that of the best MoIL (BMIM FeCl₄). These enhancements can be ascribed to reduced viscosities and an augmented number of active interaction sites in the dicationic structures. Furthermore, [E(MIM)₂][2Cl] exhibited a high degree of selectivity for CO₂ over N₂ and demonstrated stability over five recycling cycles, suggesting the potential of DILs as candidates for the development of CO₂ capture technologies.

Three chitosan ferrite nanoparticles-ZnFe ₂ O ₄ , CuFe ₂ O ₄ , and SrFe ₁₂ O ₁₉ -were synthesized via an ultrasound-assisted PEG route and evaluated as corrosion inhibitors for steel in acidic medium.

We investigate a systematically reduced series of cellulose-derived molecules (M1-M10) to evaluate how oxygen-to-carbon substitution affects electronic structure and single-molecule conductance. Using density functional theory, quantum transport calculations, and population analyses including NBO, Hirshfeld, Mulliken, Fukui indices, and MEP mapping, we characterize changes in charge distribution, orbital energies, donor-acceptor interactions, and spectroscopic properties. The results show a consistent increase in conductance from M1 to M10, accompanied by reduced charge localization, enhanced electronic delocalization, and improved alignment of frontier orbitals with the Fermi level. NBO and Fukui analyses reveal a transition from localized oxygen lone-pair orbitals in M1 to more delocalized bonding frameworks in highly reduced molecules, supporting stronger orbital overlap and more efficient tunneling. Spectroscopic trends in FTIR, UV, and ¹H-NMR further correlate with the degree of reduction, confirming progressive changes in polarity and electronic environment. Heteroatom substitution modulates the charge transport behavior of cellulose derivatives.

We discuss a systematic investigation into the liquid/vapor equilibria and interfacial properties of a homologous series of dialkyl carbonates (DACs), specifically dimethyl carbonate (D1C), diethyl carbonate (D2C), dipropyl carbonate (D3C), and dibutyl carbonate (D4C), using classical molecular dynamics simulations (CMDs). Simulations were performed over a temperature range of 350 to 450 K to elucidate the impact of alkyl chain length on the thermodynamic, liquid/vapor, and transport properties. Our results demonstrate that saturated vapor pressures decrease uniformly with increasing alkyl chain length, ranging from 6.0 bar for D1C to 0.56 bar for D4C at 450 K. Smooth adjustment of DAC volatility is useful to offer the most suitable solvent and conditions. Specific liquid densities decreased with both increasing temperature and chain length, with D1C exhibiting the highest thermal expansivity, 2.2×10⁻³ 1/K. Translational dynamics reveal a strong temperature dependence and a systematic decrease in molecular mobility as the chain length grows. A decomposition of intermolecular pairwise energies indicates that while Coulombic interactions dominate the local structure, a transition occurs from the electrostatic-driven cohesion in short-chain (D1C, D2C) to dispersion-dominated cohesion in longer-chain (D3C, D4C) molecules. These findings drive the rational design of designer solvents or mixtures, depending on the coveted balance between fast diffusion and low volatility.

Competitive solvation in an AOT system tunes sodium-mediated coupling of p -nitroaniline in the polar phase.