Search Results (272)

The widespread corrosion of mild steel in acidic environments presents a persistent and economically significant challenge across multiple industries. Compounding this issue, many conventional corrosion inhibitors carry substantial environmental and toxicological hazards, underscoring the critical need for developing high-performance, environmentally benign alternatives. This study investigates a corrosion inhibitor composite comprising collagen and 1-butyl-3-methylimidazolium bromide (BMIM·Br) for mild steel in 1.5 M HCl. Gravimetric analysis demonstrated exceptional inhibition efficiency (>95%) across a temperature range of 30–60 °C, with remarkable thermal stability evidenced by less than a 1% decrease at elevated temperatures. The adsorption process was found to be spontaneous and followed the Langmuir isotherm, with thermodynamic parameters (ΔG°_ads ≈ −17 to −19 kJ/mol) indicating a mixed physisorption–chemisorption mechanism. FTIR and XRD analyses confirmed molecular-level interactions and the formation of a more amorphous composite structure. A multi-modal adsorption mechanism, supported by Density Functional Theory (DFT) insights, is proposed, elucidating the synergy through ionic bridging and the formation of a co-accreted polymeric film. These findings establish the collagen–BMIM·Br composite as a highly effective, stable, and sustainable corrosion inhibitor for demanding industrial applications in aggressive acidic environments. Full article

TiW thin films with superior surface properties were deposited at room temperature using RF magnetron sputtering under low-temperature process conditions. The correlation between bulk plasma characteristics and thin-film properties was investigated as a function of applied RF power (200–600 W) and process pressure (1–10 mTorr). Plasma potential and ion density were measured using a Langmuir probe, while deposition rate, surface roughness, sheet resistance, and crystallinity were evaluated. Increasing the applied RF power simultaneously increased plasma potential and ion density, enhancing ion bombardment energy at both the target and substrate, which improved sputtering efficiency and deposition rate. Under low-temperature deposition, thermal stress induced by differences in thermal expansion between the film and substrate was minimal. However, limited surface diffusion of adatoms caused incomplete coalescence of nucleation islands, adversely affecting film crystallinity. Refractory metals such as tungsten exhibit strong dependence of residual stress and microstructure on deposition conditions, highlighting the importance of plasma and process parameters on TiW film properties. When RF power was increased, the enhancement in deposition rate outweighed the effect of increased ion energy, leading to tensile stress from void formation dominating over compressive stress induced by high-energy ions. This also contributed to increased grain size and reduced sheet resistance. In contrast, variations in process pressure had minor effects on plasma characteristics, resulting in limited changes in the deposited film properties. Full article

In this work, the sensor properties of multilayered Langmuir-Blodgett (LB) films of tetra-tert-butylphthalocyaninate zinc (tBuZnPc) were studied using an acoustoelectronic method. The morphology and optical properties of the fabricated films were characterized by atomic force microscopy and ultraviolet-visible spectroscopy, respectively. The LB films were deposited on surface acoustic wave (SAW) delay lines, and their gas-sensing properties were investigated. The films demonstrated high selectivity towards chloroform vapor compared to acetone, methanol, ethanol, and isopropanol. The highest selectivity was observed for the five-layer film, which can be attributed to the specific interaction of chloroform molecules with the hydrophobic cavities formed by the tert-butyl groups. Increasing the film thickness to 41 layers enhanced the absolute response to chloroform to 370 ppm; however, the selectivity decreased due to increased nonspecific adsorption. The results demonstrate the potential of using tBuZnPc LB films as sensitive coatings for the selective detection of chloroform in environmental and industrial monitoring applications. Full article

Sodium ions are the main harmful ions in coastal saline–alkali soils, and they seriously affect crop growth and soil structure. A bentonite/humic acid composite hydrogel, synthesized via graft copolymerization as a new type of water-retaining agent, can adsorb excessive Na⁺ in soil, thereby slowing down its adverse effects. This study used batch adsorption experiments to systematically investigate the effects of contact time, initial concentration, pH, temperature, and repeated cyclic adsorption on Na⁺ adsorption performance of the hydrogel material. The results indicated that Na⁺ equilibrium was achieved in 25 min, and the maximum adsorption capacity was 91.29 mg/g. Optimal adsorption occurred at pH 6–8.5, particularly in neutral to weakly alkaline conditions. At 30–50 °C, the bentonite substrate maintained excellent adsorption performance despite structural damage to the grafted copolymer. Mechanistic analysis revealed that adsorption followed pseudo-second-order kinetics and the Langmuir isotherm model, indicating chemisorption-dominated monolayer adsorption controlled by both intra-particle and liquid film diffusion. These findings demonstrate the potential of bentonite-based hydrogels for remediating coastal saline–alkali soils by mitigating Na⁺ toxicity. Full article

Thin-film composite nanofiltration membranes were fabricated via the interfacial polymerization method from optimized polyethersulfone (PES) mixed matrix membranes, using m-phenylenediamine and trimesoyl chloride monomers, which produced a selective polyamide layer and were used for heavy metal removal. The concentration of trimesoyl chloride (TMC) is a critical factor to govern the properties of the selective polyamide layer, which directly influences the surface morphology and selective performance of (0.5 wt%) PES-coreshell-Fe₃O₄/ZnO membranes. Morphological structure, illustrated by SEM images, elucidated the role of TMC addition. FTIR spectra validated the successful formation of the amine and acyl chloride groups. Performance studies illustrated that NF3 (made from 0.1 w/v% of TMC) showed a unique salt rejection trend (NaCl > Na₂SO₄ > MgCl₂) with an optimal salt rejection of 52.64%, 50.91%, and 12.67%. A low concentration of 0.1 w/v% of the NF3 membrane was the most optimal high-performance membrane. The adsorption rate of NF3 for Pb(II) ions in real environmental wastewater is attributed to the tailored surface chemistry of the polyamide layered thin-film/PES-coreshell-Fe₃O₄/ZnO nanocomposites of the membranes. The maximum Langmuir adsorption capacity at the optimal pH = 5 was 8.8573 mg/g at 25 °C. The fabricated adsorptive nanofiltration membranes alleviated the presence of Pb(II) ions and other competing ions present in environmental wastewater. Full article

Methodological fusion of materials chemistry, which enables us to create materials, with nanotechnology, which enables us to control nanostructures, could enable us to create advanced functional materials with well controlled nanostructures. Positioned as a post-nanotechnology concept, nanoarchitectonics will enable this purpose. This review paper highlights the broad scope of applications of the new concept of nanoarchitectonics, selecting and discussing recent papers that contain the term ‘nanoarchitectonics’ in their titles. Topics include controls of dopant atoms in solid electrolytes, transforming the framework of carbon materials, single-atom catalysts, nanorobots and microrobots, functional nanoparticles, nanotubular materials, 2D-organic nanosheets and MXene nanosheets, nanosheet assemblies, nitrogen-doped carbon, nanoporous and mesoporous materials, nanozymes, polymeric materials, covalent organic frameworks, vesicle structures from synthetic polymers, chirality- and topology-controlled structures, chiral helices, Langmuir monolayers, LB films, LbL assembly, nanocellulose, DNA, peptides bacterial cell components, biomimetic nanoparticles, lipid membranes of protocells, organization of living cells, and the encapsulation of living cells with exogenous substances. Not limited to these examples selected in this review article, the concept of nanoarchitectonics is applicable to diverse materials systems. Nanoarchitectonics represents a conceptual framework for creating materials at all levels and can be likened to a method for everything in materials science. Developing technology that can universally create materials with unexpected functions could represent the final frontier of materials science. Nanoarchitectonics will play a significant part in achieving this final frontier in materials science. Full article

Chloride-ion (Cl⁻)-induced corrosion of steel bars is a major threat to the durability of marine concrete structures. To address this, a type of calcined CaFeAl-layered double oxide (LDO-CFA) with different calcination temperatures was used to enhanced the Cl⁻ adsorption, compressive strength, and corrosion resistance of sulphate-resistant Portland cement (SRPC)-based materials. Experimental results demonstrated that LDO-CFA exhibited high Cl⁻ adsorption capacity in both CPSs and cement-based materials. Specifically, LDO-750-CFA reached 1.98 mmol/g in CPSs—60.1% higher than LDHs-CFA—and followed the Langmuir model, indicating monolayer adsorption. It also reduced the free Cl⁻ content of SRPC paste to 0.255–0.293% after 28 days, confirming its sustained adsorption over extended curing. Furthermore, LDO-CFA positively influenced the compressive strength at all curing ages. At an optimal dosage of 0.8 wt.%, LDO-750-CFA paste significantly improved the compressive strength, increasing it by 22.1% at 7 days and 15.6% at 28 days compared to the control. Electrochemical analysis confirmed the superior corrosion resistance of the LDO-750-CFA system. The property enhancement originated from LDO-750-CFA’s synergistic effects, which included pore refinement, increased tortuosity, Cl⁻ adsorption by structural memory, a PVP-induced passive film, and PVP-improved dispersion. Overall, this work provides a framework for developing LDO-750-CFA-based composites, paving the way for more durable marine concrete. Full article

In response to the increasing demand for environmentally friendly and cost-effective adsorbents in wastewater treatment, this study reports the green synthesis, characterization, and application of a magnetic epichlorohydrin Rosa canina (m-ECH-RC) nanocomposite for removing Safranin O (SO), a commonly used cationic dye in textile effluents. The synthesized material was characterized using Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and zeta potential analyses to reveal its surface morphology, pore structure, functional groups, crystallinity, and colloidal stability. Adsorption performance was systematically tested under various conditions, including pH, adsorbent dose, contact time, ionic strength, and initial dye concentration. Kinetic analyses revealed that the adsorption process of Safranin O dye mainly obeys pseudo-second-order kinetics, but intraparticle and film diffusion also contribute to the process. As a result of the Isotherm analysis, it was found that the adsorption process conformed to the Langmuir model. Testing on real textile wastewater samples demonstrated a removal efficiency of 75.09% under optimized conditions. Reusability experiments further revealed that the material maintained high adsorption–desorption performance for up to five cycles, emphasizing its potential for practical use. These findings suggest that m-ECH-RC is a viable and sustainable adsorbent for treating dye-laden industrial effluents. Full article

A plane reactor illuminated by LEDs was used to study the kinetics of the photocatalytic mineralization of formic acid in a TiO₂ film. Two of the most widespread types of kinetics were considered to see if their popularity is deserved. More specifically, one-parameter quadratic-type and Langmuir–Hinshelwood-type kinetics were compared against the concentration–time experimental data at different levels of illumination. Closed-form solutions, which allow for the calculation of substrate concentration over time, were derived for the application of the integral method of kinetic analysis. The considered factors, which affect the reaction rate, were the substrate concentration and the rate of photon absorption (RPA) and were varied in order to investigate most of the possible kinetic regimes. The possible onset of limitations due to external and internal mass transfer and transport of the photons was analyzed and discussed. Thanks to the absence of such limitations in the system under examination, it was possible to appraise the “intrinsic” kinetics directly. Both the models were apt to fit the observed decrease in the substrate concentration with time, even if with different soundness. However, substantial differences between the two models were evidenced in the capabilities to reliably reproduce the effects of the RPA. Full article

Silver thin films are widely utilized in plasmonic, electronic, and catalytic devices due to their excellent conductivity, optical properties, and surface activity. However, the nanostructure and performance of Ag films are highly dependent on deposition parameters, particularly during radio-frequency magnetron sputtering (RF-MS). In this study, we systematically investigate the effects of RF power, sputtering time, and substrate type on the growth behavior, crystallinity, and electrical conductivity of Ag films. Optical emission spectroscopy (OES) and Langmuir probe diagnostics were employed to analyze the plasma environment, revealing the evolution of electron temperature and plasma density with varying RF powers. Structural characterizations using XRD, SEM, and AFM demonstrate that higher RF power results in reduced grain size, increased film density, and improved crystallinity, while deposition time influences film thickness and grain coalescence. Substrate material also plays a key role, with Cu substrates promoting better crystallinity due to improved lattice matching. Electrical measurements show that denser films with larger grains exhibit lower sheet resistance. These findings provide a comprehensive understanding of the plasma–film interplay and offer strategic insights for optimizing silver nanofilms in high-performance optoelectronic and catalytic systems. Full article

This study concerns the evaluation of adhesive and wettability energetic signatures of a model orthodontic wire exposed to commercial mouthrinses. The surface wetting properties were evaluated from the contact angle hysteresis (CAH) approach applied to dynamic contact angle data derived from the original drop on a vertical filament method. Young, advancing, receding CA apart from adhesive film pressure, surface energy, work of adhesion, etc. were chosen as interfacial interaction indicators, allowing for the optimal concentration and placement of the key component(s) accumulation to be predicted for effective antibacterial activity to eliminate plaque formation on the prosthetic materials. Surfactant compounds when adsorb at interfaces confer rheological properties to the surfaces, leading to surface relaxation, which depends on the timescale of the deformation. The surface dilatational complex modulus E, with compression elasticity E_d and viscosity E_i parts, determined in the stress–relaxation Langmuir trough measurements, exhibited the viscoelastic surface film behavior with the relaxation times (0.41–3.13 s), pointing to the vertically segregated film structure as distinct, stratified layers with the most insoluble compound on the system top (as indicated with the 2D polymer film scaling theory exponent y = 12.9–15.5). Kinetic rheology parameters could affect the wettability, adhesion, and spreading characteristics of mouthrinse liquids. Full article

In this research work, the electrochemical evaluation of a non-ionic gemini surfactant as a green corrosion inhibitor for X100 pipeline steel in CO₂-saturated brine solution was carried out by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves (PPC). The corrosion inhibition performance of the gemini surfactant was studied in static and hydrodynamic conditions at room temperature and 60 °C. Electrochemical measurements showed that the inhibitor’s performance was enhanced with increasing inhibitor concentration and with increasing exposure time at room temperature, reaching the highest inhibition efficiency (η) at 100 ppm. With increasing temperature, the inhibitor efficiency decreased, with similar behavior at all concentrations. The analysis of the cathodic polarization curves at different rotation speeds showed the strong influence of mass transport on the cathodic process in the absence and the presence of the inhibitor. Under hydrodynamic conditions, PPC and EIS results indicated that the best inhibitor performance was with a concentration of 50 ppm, achieving a maximum inhibition efficiency of 91%. The adsorption of the inhibitor molecules on the surface obeyed the Langmuir isotherm, and the type of adsorption was mixed in all the study conditions. Surface characterization by scanning electron microscopy (SEM) revealed the formation of a protective corrosion inhibitor film. Full article

The interaction between carbon nanoparticles (CNs) and Langmuir monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) as a model pulmonary surfactant (PS) film was studied to shed light on the physicochemical bases underlying the potential adverse effects associated with pollutant inhalation. The results indicated that the surface pressure–area isotherms of the DPPC monolayers shifted toward lower molecular areas, and the compression modulus was reduced in the presence of CNs, hindering the ability of the DPPC monolayers to reduce the surface tension. The relaxation process of the DPPC monolayers were influenced, and the surface morphology and the continuity of the monolayers were destroyed by the penetration of CNs into the DPPC monolayers. The molecular dynamics simulation revealed that particle incorporation into the DPPC monolayers reduced the packing density of the DPPC molecules, worsening the mechanical performance of the monolayers. This effect was attributed to the strong binding trend between the CNs and the DPPC molecules. These results demonstrated that CNs could alter the relaxation mechanisms of the PS film, and this may cause a modification of the inhaled particle transport at the PS film and contribute to adverse health effects in the respiratory system of workers involved in the CN production process. Full article

Arabinoxylan is a polysaccharide with film-forming properties, present in corn fiber, and a low-value by-product. The extract has a deep brown color, producing films of the same shade, which may not be appealing. This study addresses, for the first time, the adsorption of colored compounds present in an arabinoxylan extract using resin MN102. The resin successfully adsorbed the colored compounds from the arabinoxylan extract. After four consecutive adsorption/desorption cycles, the efficiency of the resin was similar, only decreasing from 63.3% to 52.9%. Langmuir and Freundlich models were fitted to the results of adsorption isotherm experiments, with the Freundlich model demonstrating the best fit to the experimental results. A fixed-bed column loaded with the resin was used for the removal of the colored compounds from the arabinoxylan extract, and the effect of the volumetric flow rate was investigated. The Yan and log-Gompertz models showed the best fit to the experimental breakthrough curves. This study systematically evaluated the adsorption conditions, providing a comprehensive analysis of the performance of the resin in the removal of the colored compounds. Additionally, the ability of the extract to maintain its film-forming properties after decolorization was evaluated, and some of the film’s key characteristics were evaluated, namely its color, solubility in water and mechanical properties. Full article

Chiral molecules are crucial in the field of optical devices, molecular recognition, and other novel functional materials due to their unique spatially asymmetric configuration and optical activity. In this study, a chiral molecule, Cholest-3-yl (E)-3-(4-carbamoylphenyl)acrylate (CCA), was combined with dyes containing large conjugated structures, tetramethylporphyrin tetrasulfonic acid (TPPS), and Nickel(II) phthalocyanine-tetrasulfonic acid tetrasodium salt (TsNiPc), and composite LB films of CCA/TPPS and CCA/TsNiPc were successfully prepared by using Langmuir-Blodgett (LB) technology. The circular dichroism (CD) test proved that the CCA/TPPS composite film had a strong CD signal at 300–400 nm, and the composite film showed chirality. This significant optical activity provides a new idea and option for the application of LB films in chiral sensors. In the Surface Enhanced Raman Spectroscopy (SERS) test, the CCA/TPPS composite film was sensitive to signal sensing, in which the enhancement factor EF = 2.28 × 10⁵, indicating that a large number of effective signal response regions were formed on the surface of the film, and the relative standard deviation (RSD) = 12.08%, which demonstrated that the film had excellent uniformity and reproducibility. The high sensitivity and low signal fluctuation make the CCA/TPPS composite LB film a promising SERS substrate material. Full article