Film Formation Research Articles

Methodology for Corrosion Inhibitor Persistency Studies in Batch Inhibition

A novel methodology and experimental apparatus were developed to address the limitations of previous studies and investigate corrosion inhibitor persistency under batch treatment conditions. This approach effectively removed all residues after inhibitor application and prevented O2 ingress during film formation and subsequent steps. A model compound corrosion inhibitor (CI) was utilized to validate the methodology and investigate the effects of solvent on CI persistency. In all experiments, CI was applied in situ on the prepared API 5L X65 steel rotating cylinder electrode inside the empty deoxygenated glass cell using a holder and vial. The setup used a reservoir of CO2-sparged uninhibited brine to continuously dilute the test electrolyte at a constant flow rate. Electrochemical measurements were performed at 20-min intervals to characterize the inhibition behavior over time.

Passivation characteristics and corrosion behavior of S32202 duplex stainless steel in different temperatures polluted phosphoric acid

The passivation characteristics of S32202 duplex stainless steel in different temperatures polluted phosphoric acid were studied by electrochemical technology and X-ray photoelectron spectroscopy, and its corrosion behavior was studied through immersion corrosion and electrochemical corrosion. The results indicate that as the temperature increases, the open-circuit potential of the sample in polluted phosphoric acid moves forward, and the surface exhibits a rapid passivation process. The main phases of the passivation film are Fe2O3, Fe3O4, Cr2O3, Cr(OH)3, and corresponding phosphates and polyphosphates. The passivation film of the sample in polluted phosphoric acid exhibits n-p-n composite semiconductor properties. As the temperature increases, the electron density and number of defects in the passivation film increase, and the vulnerability of the passivation film increases. The increase in temperature promotes the formation of a porous thick film. The corrosion types of the sample in polluted phosphoric acid are total corrosion, phase boundary corrosion, and intergranular corrosion, accompanied by pitting corrosion in local areas. The corrosion current density and passivation current density of the sample gradually increase with increasing temperature, while the counter-passivation potential and passivation index decrease, the density and protective properties of the passivation film decrease. The doping of phosphate can alleviate the dissolution process of metals, but the increase in temperature increases the solution ionic activity and accelerates the rate of charge transfer at the interface. At the same time, FePO4, CrPO4 and other phosphates are poorly protected, and their large presence is not conducive to the stability of the passivation film structure, resulting in a decrease in the corrosion resistance of the material.

The oxide films formed under the low oxygen pressure in a particular system containing competing chromium and aluminium

AbstractIn this paper, pre‐oxidation treatment was carried out at 950 °C under oxygen pressure of 10−16 atm for nickel‐10 % chromium‐x % aluminium‐1 % silicon‐0.5 % yttrium(x=0 wt.–%, 1 wt.–%, 3 wt.–%, 5 wt.–%) alloys. Morphology and structure of oxide layers on the alloys after pre‐oxidation were analyzed by scanning electron microscopy and electron discharge spectroscopy. The results showed that a chromium oxide film was formed on the surface of the alloy without aluminium addition, while the oxide layer on the surface of the alloy with aluminium addition gradually transformed into M2O3 (M=aluminium and chromium) oxide film. The oxidation behavior was analyzed by means of chemical thermodynamics, and it was seen that because the interaction coefficient,εijof aluminium and chromium is a positive value, the increase of aluminium addition will strengthen the interaction and increase the diffusion coefficient,Diof aluminium and chromium. The diffusion of chromium and aluminium in each other therefore promotes their interaction, which is beneficial to the formation of the outer oxide film. Thus, with the increase of aluminium addition, the thickness of the outer oxide film gradually increased, and the aluminium content in M2O3 (M=aluminium and chromium) increased significantly, and with 5 % aluminium added, the aluminium oxide of the outer oxide film became the main body.

Formation and characterization of Ag2La thin films designed for high $$k$$-dielectric and terahertz applications

Formation and characterization of Ag2La thin films designed for high $$k$$-dielectric and terahertz applications

Equilibrium and self-assembly of Janus particles at liquid-liquid interfaces for the film formation

This article investigates the equilibrium arrangement, self-assembly process, and subsequent curing of amphiphilic snowman-shaped Janus particles at the oil-water interface. The independent Janus particles are in vertical equilibrium state and the contact position of the oil-water interface is at the largest cross section of the particle’s hydrophobic phase. Under the effect of the surface tension and the adsorption of materials, Janus particles may form particle combinations including the particle pairs and the particle triangle, whose inner and outer sides have the liquid surface exhibiting completely opposite contact angles. Particle combinations form stable parallel double-chain structures with diverse shapes after the self-assembly process. However, the single Janus particles attain a state of mechanical equilibrium under the influence of surrounding particles, enabling them to assemble into regular array structures. The relationship of interfacial tension coefficient between phases can be changed by adjusting the oil-water system, which leads to variations in the self-assembly speed and the final arrangement results. The thin-film with uniformly distributed vertical particles is achieved by replacing the underlying deionized water with a curing agent. Based on the understanding of the interactions between irregularly shaped Janus particles at the oil-water interface, it will be convenient to achieve the controllable self-assembly and widely applications of these particles.

In Situ Morphology Control for Solution‐Printable Organic Photovoltaics

AbstractThe morphology of the photoactive layer plays an important role in both the photoelectric effect and device performance of solution‐processed organic solar cells (OSCs). Optimizing the morphology requires precise control over the complex film formation kinetics, which are influenced by a range of factors from the solution state to the solid‐film state. This review delves into the in situ characterization technologies employed to understand the active layer formation process and explores strategies for controlling film formation during key stages, including solution aggregation, nucleation, crystal growth, and phase separation. Special attention is given to the mechanism by which these strategies enable real‐time morphology control during the printing process and their potential to facilitate direct printing of active layers with optimized morphology. The goal is to offer valuable insights and guidance for managing film formation kinetics in solution‐processed OSCs, ultimately addressing the challenges of real‐time morphology control in scale‐up printing and paving the way for high‐throughput production of post‐processing‐free devices.

Design and Development of Film Forming Gel of Tavaborole by using Factorial Design

Film forming gel (FFG) could be a novel approach in film forming drug delivery system which has pulled in the intrigued of pharmaceutical researcher in improvement and characterization of skin drug delivery system. FFG were developed by varying concentration of the polymers and plasticizer. The formulations were prepared using 32 full factorial design. FFG were evaluated for important parameters like drying time, drug release, antifungal activity, skin irritation and stability studies. The FFG was characterized for pH, viscosity, drug content, effective dosage volume and mechanical properties of the film formed after application; bioadhesion and water vapour permeability were also tested. All the formulations showed results within acceptable range for various tests. The optimized formulation showed drug release of 98.76% and antifungal activity in terms of efficacy as 95.83%. It is stated that the created formulation will shorten therapy duration, increase patient acceptance, and represent a breakthrough in the treatment of skin infections.

Molecules as Lubricants at the Nanoscale:Tunable Growth of Organic Structures from Nano- to Millimeter-Scale Using Solvent Vapour Annealing.

The creation of ordered structures of molecules assembled from solution onto a substrate is a fundamental technological necessity across various disciplines, spanning from crystallography to organic electronics. However, achieving macroscopic order poses significant challenges, since the process of deposition is inherently impacted by factors like solvent evaporation and dewetting flows, which hinder the formation of well-organized structures. Traditional methods like drop casting or spin coating encounter limitations due to the rapid kinetics of solvent evaporation, leading to limited control over final uniformity and order. In response to these challenges, Solvent Vapour Annealing (SVA) has emerged as a promising solution for realizing ordered molecular structures at scales ranging from nano- to milli- meters. SVA decouples the self-assembly stage from the deposition stage by utilizing solvent vapours which can enable rearrangement, movement, and diffusion of large molecules on the surface even on a macroscopic scale. Essentially acting as "molecular lubricants," solvent vapours enable the formation of well-ordered molecular films. This review discusses the advancements, obstacles, and promising strategies associated with utilizing SVA for the development of innovative nanostructured thin films, and emphasizes the originality and effectiveness of molecular assembly on substrates achieved through this approach.

Overcoming Microstructural Defects at the Buried Interface of Formamidinium-Based Perovskite Solar Cells.

Since the advent of formamidinium (FA)-based perovskite photovoltaics (PVs), significant performance enhancements have been achieved. However, a critical challenge persists: the propensity for void formation in the perovskite film at the buried perovskite-interlayer interface has a deleterious effect on device performance. With most emerging perovskite PVs adopting the p-i-n architecture, the specific challenge lies at the perovskite-hole transport layer (HTL) interface, with previous strategies to overcome this limitation being limited to specific perovskite-HTL combinations; thus, the lack of universal approaches represents a bottleneck. Here, we present a novel strategy that overcomes the formation of such voids (microstructural defects) through a film treatment with methylammonium chloride (MACl). Specifically, our work introduces MACl via a sequential deposition method, having a profound impact on the microstructural defect density at the critical buried interface. Our technique is independent of both the HTL and the perovskite film thickness, highlighting the universal nature of this approach. By employing device photoluminescence measurements and conductive atomic force microscopy, we reveal that when present, such voids impede charge extraction, thereby diminishing device short-circuit current. Through comprehensive steady-state and transient photoluminescence spectroscopy analysis, we demonstrate that by implementing our MACl treatment to remedy these voids, devices with reduced defect states, suppressed nonradiative recombination, and extended carrier lifetimes of up to 2.3 μs can be prepared. Furthermore, our novel treatment reduces the stringent constraints around antisolvent choice and dripping time, significantly extending the processing window for the perovskite absorber layer and offering significantly greater flexibility for device fabrication.

Red-emitting copper nanoclusters for ultrasensitive and selective detection of creatinine and its application in portable smartphone-based paper strips and polymer thin film

In this work, a quantitative paper-based sensor integrated with smartphone-application was developed using poly(sodium 4-styrenesulfonate) stabilized copper nanoclusters (PSS-CuNCs) as a fluorescence probe to detect creatinine (CRN). The surface morphology and optical properties of PSS-CuNCs were verified using UV–vis absorption, zeta-potential, photoluminescence, high resolution transmission electron microscopy (HR-TEM) and Fourier-transform infrared (FI-IR) and X-ray photoelectron (XPS) spectroscopy. PSS-CuNCs exhibited strong red fluorescence with the emission peak centered at 654 nm upon excitation at 390 nm. PSS-CuNCs was also used to determine CRN because of their excellent fluorescence properties. The fluorescence of PSS-CuNCs was quenched significantly by adding different concentrations of CRN, which mainly originated from the formation of ground state complexation. The PSS-CuNCs probe showed high sensitivity with a low limit of detection (LOD) of 2.48 nM and high selectivity even in the presence of other interfering analytes. This assay was also used to measure CRN in real samples. Additionally, test paper-based assay has been developed to detect CRN using smartphones. The developed assay provides a reliable, cost-effective, sensitive and portable on-site method to measure CRN levels by utilizing fluorescence color changes. Incorporation of PSS-CuNCs into poly(vinyl alcohol) resulted in the formation of fluorescent transparent polymer thin films with high photostability.

In situ growth of curcumin-loaded cellulose composite film for real-time monitoring of food freshness in smart packaging

Visual pH-responsive packaging material is particularly important in food supply chain safety monitoring due to their non-destructive monitoring method and intuitive result. However, it has always been limited by the instability performance of pH-response components and carriers, which further hinders its wide food safety application. To address these challenges, we selected cellulose with remarkable biocompatibility and mechanical properties as the carrier, and high pH-responsive curcumin to develop a smart packaging material (RC/GC composite film) with real-time food safety monitoring. Compared with pure cellulose film, the RC/GC composite film exhibited excellent mechanical properties (4-fold enhancement) and thermal stability (100 °C increasing). Meanwhile, based on the first reported strategy of curcumin in-situ growth during cellulose film formation, the RC/GC composite film exhibited exceptional antioxidant activity (89.2 %), antimicrobial property (91.6 %), and significant pH-responsive sensitivity (within 15 s). This innovative approach offers a new strategy for easy-to-use and effective monitoring of food spoilage in packaging materials.

Interfacial Assembly of Free-Standing Polymer-Phenolic Films for Antibacterial and Antiultraviolet Applications.

We report a facile interfacial assembly strategy for the preparation of flexible polyphenol-based films for antibacterial and antiultraviolet applications. The free-standing films can be instantaneously formed via spraying tannic acid (TA) at the surface of carboxymethyl chitosan (CMCS) solutions. Compared with the traditional casting-evaporation procedure on solid substrates, the liquid interfacial assembly method for the construction of free-standing films is rapid and facile, which prevents the interface separation procedure from the substrates. The thickness and mechanical properties of the films are well controlled by changing the incubation time. The low-field nuclear magnetic resonance was used to analyze the water distributions inside the films and to distinguish the cross-linked structure of CMCS-TA films with different thicknesses, revealing the dynamics of the film formation process. Importantly, the films exhibit outstanding antibacterial and antiultraviolet properties, which are promising in the applications of wound dressings. This study provides a new avenue for the assembly of flexible free-standing films with multifunctionality via a facile and low-cost fabrication process.

Advanced evaluation of novel quinoline derivatives for corrosion inhibition of mild steel in acidic environments: A comprehensive electrochemical, computational, and surface study

Corrosion poses a significant threat to the integrity and longevity of iron and its alloys, which are crucial materials for modern industry and infrastructure. This study investigates the effectiveness of two recently synthesized inhibitors based on quinoline structures: MPQ (2-methyl-5-(propoxymethyl) quinolin-8-ol) and AAQ ((((2-aminoethyl)amino)methyl)-2-methylquinolin-8-ol) in protecting steel against environmental degradation, particularly in acidic and chloride-rich conditions such as hydrochloric acid. The inhibitors exhibited significant corrosion inhibition efficiencies of 92.37 % for MPQ and 84.13 % for AAQ, as demonstrated through electrochemical analysis. Surface characterization techniques, including SEM-EDX(Scanning Electron Microscopy with Energy Dispersive X-ray analysis), AFM (Atomic Force Microscopy), and contact angle measurements, revealed the formation of a protective barrier film that reduces the corrosion rate. Additionally, theoretical calculations using the Gaussian package provided insights into the adsorption behaviors and protective mechanisms of the inhibitors on mild steel surfaces. The findings contribute to the ongoing search for viable corrosion inhibitors, offering prospects for application in industries and critical infrastructures to enhance corrosion protection and durability.

SILAR synthesized α-Fe2O3 thin film anode for the development of all binder-free, high-performing Mg-ion asymmetric supercapacitors

Divalent-ion electrolyte-based supercapacitors (D-ISCs) have been gaining prominence due to their affordability and potential to deliver superior electrochemical performance as compared to single-ion electrolyte-based supercapacitors. Moreover, to satisfy the high energy demands of advanced electronic devices, a rational combination of electrodes and electrolytes in D-ISCs is required to enhance their power and energy densities further. Therefore, the present work describes the development of all binder-free magnesium-ion supercapacitor (Mg-ISC) using α-Fe2O3 as an anode and MnO2 thin films as a cathode. The binder-free thin films are fabricated using the SILAR method, allowing for direct formation of uniform and nanocrystalline thin films on the substrate, confirmed through structural and morphological analysis. Individually, both α-Fe2O3 and MnO2 thin film electrodes employed as anode and cathode exhibit excellent electrochemical properties, achieving a specific capacitance (Csp) of 381 F g−1 and 587 F g−1 at 0.2 mA cm−2, respectively, and confirms that both electrodes can be effective and reversible host materials. Furthermore, the developed Mg-ISC delivers a remarkable Csp of 234 F g−1 at a current density of 0.2 mA cm−2. Moreover, the aqueous Mg-ISC achieves a significant energy density of 105.2 Wh kg−1 at a high-power density of 619.4 W kg−1, suggesting that the device can deliver both high energy and power simultaneously. Moreover, Mg-ISC retained 86 % of its capacitance through 10,000 cycles at 5 mA cm−2. The current work lays the basis for developing D-ISC that are safe, sustainable, and provide improved electrochemical performance for a wide range of applications.

Probing the efficiency and mechanism of hydrogen permeation inhibition in pipeline steel by organic inhibitors

A hydrogen economy will require the use of steel pipelines to transport and store hydrogen. Methods and materials are urgently needed to prevent the embrittlement of steel pipelines in hydrogen service. In this work, we show that hydrogen permeation into pipeline steel can be mitigated by organic inhibitors, as demonstrated by a typical organic inhibitor benzotriazole (BTA) under simulated X65 steel pipeline cathodic protection conditions. Electrochemical and surface analytical techniques were used to probe the efficiency and mechanism of hydrogen permeation inhibition. In particular, a novel multi-electrode array method was designed to probe the inhibitor film by measuring local impedance and hydrogen charging currents. The ability and efficiency of BTA to inhibit hydrogen permeation were found to be closely associated with the formation and coverage of inhibitor films on steel surfaces. A model is proposed to illustrate the mechanism of hydrogen permeation inhibition by organic inhibitors.

Phosphorus doped hydrogenated silicon oxycarbide: Film formation, properties and its application on silicon heterojunction solar cell

An ultrathin phosphorus doped hydrogenated microcrystalline silicon oxycarbide (n-μc-SiCO:H) layer deposited by plasma enhanced chemical vapor deposition (PECVD) method can be used as a window layer for silicon heterojunction solar cells. The optical and electrical properties of n-μc-SiCO:H films were controlled by PECVD deposition conditions. The interplay effects of H2, CO2 and PH3 to SiH4 gas ratio on the chemical composition, material structure and properties of n-μc-SiCO:H film were systematically determined. O, H, C and P atoms were observed to incorporate into the silicon network of n-μc-SiCO:H layer, while most of the atoms bond directly to Si atoms. Incorporation of oxygen and carbon atoms into n-μc-SiCO:H film, confirmed by XPS as formation of Si-O and Si-C bonds, enlarged the optical absorption band gap (Eg) value. Both film crystallinity and phosphorus concentration in n-μc-SiCO:H layer were observed to be controlled by the H2, CO2 and PH3 to SiH4 gas ratio. The electric performance of HJT solar cell was depended on the optical and electrical properties of n-μc-SiCO:H layer. An average efficiency (across ∼ 120 cells) of 26.32 % was achieved in cells with optimized deposition parameters for the n-μc-SiCO:H layer. The reaction gas ratio was also the dominant factor in determining the number and size of nanoscale Si crystallites embedded in the n-μc-SiCO:H layer. The conductivity of n-μc-SiCO:H layer was determined by the activated phosphorus concentration but independent of the total phosphorus concentration. It was also found that large concentrations of small Si crystallites of size less than 3 nm improved film conductivity.

Thermal elastohydrodynamic lubrication analysis of the roller enveloping hourglass worm drives considering the roller self-rotation behavior

Elastohydrodynamic lubrication (EHL) plays a crucial role in worm-drive tribology. However, in roller enveloping hourglass worm (REHW) drives, the unique rolling motion of the rollers reduces friction but presents challenges in accurately analyzing the film formation characteristics. To address this, a method for calculating the time-varying meshing characteristic parameters, considering the influence of the roller's self-rotation behavior, is proposed. A thermal EHL numerical model for REHW drives was established based on EHL theory by integrating these parameters. The lubrication characteristics at various meshing instants and contact positions were analyzed, and operational conditions and design parameters were identified to enhance lubrication performance. High-speed and heavy-load REHW drives have demonstrated superior lubrication performance. These findings provide theoretical guidance for optimizing lubrication performance and investigating wear in REHW drives.

MXene-Embedded PEDOT:PSS Hole-Transport Material for Lead-Free Perovskite Solar Cells.

Improving the energy alignment between charge-transport layers and the perovskite is crucial for further enhancing the photovoltaic performance of tin-based perovskite solar cells (PSCs). Herein, the role of Ti3C2T x MXene in a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transport layer (HTL) on the photovoltaic properties of PSCs is investigated as a function of its concentration. An improved perovskite film formation with reduced pinhole density and a more uniform contact potential difference is noted when MXene is embedded in the PEDOT:PSS HTL. The work function of the HTL is increased according to photoelectronic measurements, leading to a favorable energy alignment with the HOMO of PEA0.2FA0.8SnI3 perovskite. PSCs fabricated using a MXene-embedded PEDOT:PSS HTL delivered a power conversion efficiency (PCE) of 8.35% compared to 7.35% from the pristine counterpart, while retaining ∼90% of its initial PCE after 450 h of storage in a N2 atmosphere.

Composite side chain induced ordered preaggregation in liquid state for high-performance non-halogen solvent processed organic solar cells

Eco-friendly organic solar cells (OSCs) have become a promising choice for commercialization, particularly emphasizing the importance of using non-halogenated solvents. However, non-halogenated OSCs with high-performance remain limited due to the uncontrollable preaggregation behaviors of photovoltaic materials in these solvents. Here, composite side chain engineering was shown to enhance photovoltaic performance of non-halogenated solvents processed OSCs by developing two small molecular acceptors, C10ch-F and C10ch-Cl, and to study the preaggregation behavior in toluene. Through a combination of in situ absorption analyses and molecular dynamics simulations, we demonstrated that the cyclohexyl moiety at the tail of the linear chain acted as a fixative, effectively mitigating the entanglement of the amorphous long chains and prolonging the kinetics of film formation process, resulting in reinforced molecular packing with a preferential face-on orientation. With effective charge generation, transport, and collection, C10ch-Cl-based device from Tol showed an impressive PCE of 18.4 % and 19.2 % in the binary and ternary systems. Moreover, the PCE remained at 80 % of its initial value after 790 h of continuous illumination, indicating excellent photostability. The uncovered preaggregation and realized excellent performance obtained through the composite side chain strategy may allow for further synthetic advances, potentially leading to significantly improved eco-friendly OSCs.

Sputter deposited silver niobate thin films: Pathway towards phase purity

The quest for environmentally sustainable alternatives to lead-based dielectric materials in dielectric capacitors has led research to the exploration of options such as silver niobate (AgNbO3), which has been found to display excellent energy storage properties. Homogeneity and phase-purity of the used thin films are vital for optimal performance of these devices. In this study, a systematic variation of oxygen partial pressure and bias voltage during reactive d.c. magnetron co-sputtering from metallic targets is employed to synthesise AgNbO3 thin films. Structural and chemical composition of the films are investigated using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, elastic recoil detection analysis, and Rutherford backscattering spectrometry. The findings emphasise the necessity of precise parameter control during deposition to avoid the presence of undesirable secondary phases like Ag and Ag2Nb4O11 and to ensure the formation of homogeneous and phase-pure AgNbO3 thin films. The gained insights demonstrate the potential of reactive d.c. magnetron sputtering for the deposition of lead-free AgNbO3 thin films, offering pathways for enhanced environmental compatibility of future dielectric capacitors.