Etching Research Articles

Incorporating pre-stretching into electroless copper plating for conductivity improvement of elastic nylon fabric: application in ECG electrode

Incorporating pre-stretching into electroless copper plating for conductivity improvement of elastic nylon fabric: application in ECG electrode

Simulation of tetrahydrofuran-water hydrate formation with a combined cellular automata method and finite difference

The present work simulates the formation of Tetrahydrofuran hydrate considering a reactor under atmospheric pressure. Heat transfer by conduction and convection were considered as the governing mechanisms. The simulation approach based on the cellular automata method (CA) and finite differences was developed to simulate the THF-water hydrate formation and calculate the temperature in the whole range, including the solution and hydrate phases. The finite difference method was used to calculate the temperature of both phases within the reactor during each time step. The model CA contains several transition rules that define the state of the cells (solid or liquid) during each time step and estimate the probability of phase change from liquid to solid (hydrate formation) or vice versa (hydrate dissociation). The simulation method was applied to study the effects of the temperature of the copper plate on the left and right sides and the initial temperature of the THF-water solution on the thickness of the hydrate layer, the number of hydrate cells formed during the growth process, and the temperature distribution in the hydrate and liquid phases. The simulation results were in good agreement with the experimental data.

Properties and microstructure regulation of electrodeposited ultra-thin copper foil in a simple additive system

Hydroxyethyl cellulose (HEC) has been commonly used in a variety of complex formulations for acid copper plating. However, the roles of HEC acting in acid copper plating still lacks of systematic investigation. To explore the efficacy of HEC in the deposition of the ultra-thin electrodeposited copper foil (ED-Cu), we designed a simple formulation system, in which HEC was used as the single organic additive. Using electron backscatter diffraction (EBSD), microstructures of the prepared ED-Cu was comprehensively investigated. The results showed that the ED-Cu was characterized by a mixed distribution of columnar and equiaxed crystals. Grain morphology, dislocation density and crystal orientation of the ED-Cu could be regulated by HEC concentration. According to the cyclic voltammetry (CV) and chronoamperometry (CA) results, the introduction of HEC between 0–200 ppm led to a polarizing effect, which marginally increased with the HEC concentration. Meanwhile, the increase of HEC concentration enhanced the nucleation rates of copper and reduced the grain size during instantaneous nucleation. The introduction of the HEC also altered the preferred orientation of the ED-Cu foil. Mechanical results showed that the optimum concentration of HEC addition was 125 mg l−1.

Advancements in gas phase pollutant removal: A comprehensive study on the sorption of CO2 and SO2 on modified carbon monoliths

The synthesis of carbon monoliths using activated carbon treated with phenol-formaldehyde resin has been identified as a promising approach for the removal of pollutants from the gas phase. Monolithic adsorbents were synthesised and modified by adding silica, acid etching, and high temperature activation with CO2. Sorption capacities were determined by CO2 and SO2 adsorption tests. Preliminary findings indicated that the unmodified monoliths exhibited limited porosity. The activation process significantly altered the textural parameters, resulting in an increase in surface area and adsorption and desorption capacity. The modification yielded a monolith with a specific surface area of 598 m2/g and a pore volume of 438 mm3/g. The sorption capacity of the monoliths towards CO2 and SO2 was 1.64 mmol/g and 3.93 mmol/g, respectively. The modifications introduced developed the sorption capacity of the monoliths, enabling the regeneration process and its further use in subsequent measurement cycles.

Determining rational parameters for the treatment of concentrated wastewater from etching site by using combined systems producing sediments of predefined composition

The object of this study is model solutions, spent sulfuric acid and chloride acid etching solutions, degreasing of metal products at enterprises. The paper reports results of research on the possibility of obtaining sediments of predefined composition and reducing the consumption of chemical reagents in comparison with conventional cleaning schemes. The systematization of the elements of the technological scheme has been shown, which provides for the treatment of concentrated wastewater of the etching area in combined systems with obtaining sediments of predefined composition and is the basis for the implementation of resource-saving technology. Rational parameters were established for the state (рН=3‒4, Eh=+0.3‒+0.33 V, and rH2=16.3–19.38 V) and technological parameters (degree of iron extraction ψ=0.8, reagent consumption from the stoichiometric norm of B=0.8). Such parameters provide the proper conditions for the oxidation of organic compounds and their co-precipitation with insoluble iron hydroxy compounds (the maximum degree of extraction of organic impurities is 86 %). The formed precipitate corresponds to the FeOOH.nH2O composition, contains 2‒3 % of organic impurities, and is subject to burial. As a result of studies on the treatment of concentrated iron-containing wastewater, the obtained sediment is ready for further utilization by processing. The composition of this sediment corresponds to the natural mineral limonite FeOOH (Fe2O3.nH2O) and is formed at pH values from 3.5 to 7.5 with rH2 values from 26 V to 21 V and at technological regeneration parameters of pH=4.0–4.6; rH2 =23.34–32.25 V. As a result of research into the deep purification of wastewater using a magnetic device, a suspension of sediment of ferromagnetic impurities (hydroxo compounds of iron) is obtained, which could be the basis for extraction or production of magnetically favorable dispersed material.

Fe-Doped Ni2P/NiSe2 Composite Catalysts for Urea Oxidation Reaction (UOR) for Energy-Saving Hydrogen Production by UOR-Assisted Water Splitting.

The development of efficient urea oxidation reaction (UOR) catalysts helps UOR replace the oxygen evolution reaction (OER) in hydrogen production from water electrolysis. Here, we prepared Fe-doped Ni2P/NiSe2 composite catalyst (Fe-Ni2P/NiSe2-12) by using phosphating-selenizating and acid etching to increase the intrinsic activity and active areas. Spectral characterization and theoretical calculations demonstrated that electrons flowed through the Ni-P-Fe-interface-Ni-Se-Fe, thus conferring high UOR activity to Fe-Ni2P/NiSe2-12, which only needed 1.39 V vs RHE to produce the current density of 100 mA cm-2. Remarkably, this potential was 164 mV lower than that required for the OER under the same conditions. Furthermore, EIS demonstrated that UOR driven by the Fe-Ni2P/NiSe2-12 exhibited faster interfacial reactions, charge transfer, and current response compared to OER. Consequently, the Fe-Ni2P/NiSe2-12 catalyst can effectively prevent competition with OER and NSOR, making it suitable for efficient hydrogen production in UOR-assisted water electrolysis. Notably, when water electrolysis is operated at a current density of 40 mA cm-2, this UOR-assisted system can achieve a decrease of 140 mV in the potential compared to traditional water electrolysis. This study presents a novel strategy for UOR-assisted water splitting for energy-saving hydrogen production.

Titanium Surface Modification Techniques to Enhance Osteoblasts and Bone Formation for Dental Implants: A Narrative Review on Current Advances

Surface modifications for titanium, a material of choice for dental implants, can greatly alter the surface micro/nanotopography and composition of implants, leading to notable enhancements in their hydrophilicity, mechanical properties, osseointegration performance, and antibacterial performance, as well as their impacts on osteoblast activity and bone formation processes. This article aims to update titanium surface modification techniques for dental implants from the past to the present, along with their effects on osteoblasts and bone formation, by thoroughly summarizing findings from published studies. Peer-reviewed articles published in English consisting of in vitro, in vivo, and clinical studies on titanium dental implant surface treatments were searched in Google Scholar, PubMed/MEDLINE, ScienceDirect, and the Scopus databases from January 1983 to December 2023 and included in this review. The previous studies show that implant surface roughness, condition, and hydrophilicity are crucial for osteoblast adhesion and growth. While various techniques enhance osseointegration comparably, one of the most common approaches to accomplishing these properties is sandblasting large-grit acid etching surface treatment and coating with hydroxyapatite or chitosan. In conclusion, this review points out the efficacy of different subtraction and addition techniques in enhancing the surface properties of titanium dental implants, promoting favorable outcomes in terms of osteoblast activity and bone formation in various degrees. However, most existing studies predominantly compare treated and non-treated titanium, revealing a need for more comprehensive studies comparing the effects of various modification techniques. Moreover, further investigation of factors playing a role in the dynamic osseointegration process in addition to osteoblasts and their functions, as well as improved surface modification techniques for the treatment of compromised patients, is greatly required.

ПРОТИВОКОРРОЗИОННАЯ ЗАЩИТА МЕДИ МАСЛЯНЫМИ КОМПОЗИЦИЯМИ С КОМБИНИРОВАННОЙ ДОБАВКОЙ М-531

The use of anti-corrosion protection is necessary to maintain the performance of agricultural machinery and equipment. The effectiveness of oil compositions with the addition of M-531 in relation to copper was studied. The compositions were obtained on the basis of industrial and motor M10G2k (both fresh and used) oils. Their protective ability was studied using gravimetric and electrochemical methods (polarization and impedance) studies. According to the data obtained from corrosion gravimetric tests in 0.5 M NaCl, it was noted that compositions based on M10G2k oil turned out to be the most effective when 5 wt. % of the additive, the protective effectiveness (Z) was 63%, a further increase in concentration led to a slight increase to Z = 65% at 10 wt. % M-531. The data from electrochemical measurements qualitatively confirm the data from gravimetric tests. Differences in the magnitude of protective effectiveness are associated primarily with different times of exposure to an aggressive environment: the duration of the experiment in the first case was 15 minutes, in the second - 14 days. According to the results of polarization measurements, compositions based on MMO were the most effective, already at a content of 5 wt. % additive value Z = 98%, while compositions containing 5 wt. % M-531 in I20-A and M10G2k had Z = 90%. The results of impedance studies showed that the addition of the M-531 inhibitor to MMO, M10G2K and I20-A oils affects the copper impedance hodographs. The inhibitor concentration had a significant effect on the change in Nyquist diagrams. At 3 wt. % M-531, a moderate change in copper plating impedance was observed, indicating that the inhibitor has some protective ability against corrosion, but its effectiveness may not be sufficient to fully protect copper. When the inhibitor concentration increases to 5 - 7 wt. % noticeable increase in the change in impedance indicated that a higher concentration of the M-531 inhibitor helps to improve the protective properties of the copper coating.

Effect of hydroxyapatite nanoparticles coating of titanium surface on biofilm adhesion: An in vitro study

AimTo evaluate the adhesion of mono and duospecies biofilm on a commercially available dental implant surface coated with hydroxyapatite nanoparticles (nanoHA). Material and methodsTitanium discs were divided into two groups: double acid-etched (AE) and AE coated with nanoHA (NanoHA). Surface characteristics evaluated were morphology, topography, and wettability. Mono and duospecies biofilms of Streptococcus sanguinis (S. sanguinis) and Candida albicans (C. albicans) were formed. Discs were exposed to fetal bovine serum (FBS) to form the pellicle. Biofilm was growth in RPMI1640 medium with 10% FBS and 10% BHI medium for 6 h. Microbial viability was evaluated using colony-forming unit and metabolic activity by a colorimetric assay of the tetrazolium salt XTT. Biofilm architecture and organization were evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). ResultsAE surface had more pores, while NanoHA had even nanoHA crystals distribution. Roughness was similar (AE: 0.59 ± 0.07 µm, NanoHA: 0.69 ± 0.18 µm), but wettability was different (AE: Θw= 81.79 ± 8.55°, NanoHA: Θw= 53.26 ± 11.86°; P = 0.01). NanoHA had lower S. sanguinis viability in monospecies biofilm (P = 0.007). Metabolic activity was similar among all biofilms. In SEM both surfaces on C. albicans biofilm show a similar distribution of hyphae in mono and duospecies biofilms. AE surface has more S. sanguinis than the NanoHA surface in the duospecies biofilm. CLSM showed a large proportion of live cells in all groups. ConclusionsThe nanoHA surface reduced the adhesion of S. sanguinis biofilm but did not alter the adhesion of C. albicans or the biofilm formed by both species.

Моделирование и анализ распределений температуры и термомеханических напряжений в многокристальном электронном модуле

A mathematical thermomechanical model of a multi-chip electronic module (MEM) containing three silicon dies of high-power transistors fixed with a conductive adhesive on a copper plate placed on a radiator is considered in the form of a system of equations of thermal conductivity and thermoelasticity with specified boundary conditions. As a result of computational studies of the model in the COMSOL Multiphysics software environment, distributions of temperature and thermomechanical stresses in the MEM structural elements were obtained depending on the heating power, the thickness of the adhesive and the size of the model defect in the contact connection of one of the MEM crystals with a copper plate in the form of voids in the adhesive layer. It is shown that voids in the adhesive layer lead to a sharply non-uniform temperature distribution over the crystal area and thermomechanical shear stresses in the contact layer that exceed the maximum permissible values for the adhesive. It has been established that thermomechanical stresses decrease with increasing thickness of the adhesive layer and increase with increasing size of the defect(voids) in this layer. The simulation results are in good agreement with the results of measuring the thermal impedance of power transistor crystals using the modulation method, which indicates the correctness and adequacy of the developed model.

Enhanced fabrication of conical array via two-stage through mask electrochemical machining process

In response to the issues of low processing precision, poor surface quality, and low array uniformity in the fabrication process of metal array conical structures, this paper proposes a two-stage enhanced process for fabricating metal array conical structures using through-mask electrochemical machining (TMECM). The micro-convex structure with high consistency can be quickly obtained through the first electrochemical machining (ECM), and then the mask is removed and the micro-convex structure is modified twice. The top diameter of the micro-structure is reduced by using the phenomenon of electric field concentration in the ECM process, and the top curvature radius of the micro-structure is further reduced, so as to increase the height diameter ratio of the micro-structure and improve the surface quality. The results show that during the initial ECM, when the machining time is 35 s, the voltage is 20 volts, the flow rate of the acid etching solution is 1 m /s, the duty cycle is 50 %, and the frequency is 200 Hz, the stable machining of the metal array conical structure can be achieved. In the secondary electrochemical surface modification, it was found that under the conditions of working solution containing 2 mol/L nickel-based etching agent, pulse voltage of 20 V and processing time of 35 s, the method effectively improved the surface quality of the workpiece and ensured the stable manufacturing of the micro-conical array structure. The prepared microstructure height was 198 μm and the top diameter was 28 μm.

Effect of laser treatment on strength of moisture-degraded epoxy adhesive joints and microscopic observation of treated surface

ABSTRACT We examined the effect of laser processing surface treatment on the mechanical strength of adhesion. In addition to laser processing, double cantilever beam (DCB) and lap joint (LJ) specimens were prepared using an epoxy adhesive on aluminum plates that underwent acid etching, sandblasting, and acetone wiping. The open face method was employed to accelerate moisture degradation, and the tensile-shear strength and energy release rate of the specimens were measured. Laser processing resulted in remarkably high values of the measured energy release rate, even when the adhesive deteriorated. To examine the reason for the high strength, we performed a detailed fracture surface analysis and electron microscopic observation of the adhesive interface. When the interface of the fractured surface was observed, the laser treated surface was densely formed with fine filamentous protrusions that held the adhesive well. These filaments exhibited high oxidation resistance and achieved strong adhesion even when the adhesive and adherend deteriorated because of moisture. The laser treated adherend surface exhibited two strong anchoring effects owing to a significant increase in the surface area and the microfilamentous structure on the surface. However, the type of surface treatment did not have a significant effect on the LJ adhesion strength.

CSC-YOLO: An Image Recognition Model for Surface Defect Detection of Copper Strip and Plates

CSC-YOLO: An Image Recognition Model for Surface Defect Detection of Copper Strip and Plates

Fabrication of CuO/Au Nanowires on a Copper Substrate for Ultra-Sensitive SERS Sensors

To optimize the surface-enhanced Raman (SERS) phenomenon on the surface of noble metals, gold nanoparticles were synthesized on the surface of nano-sized copper wires to enhance the dispersion of gold particles on the research surface. A simple experimental procedure was carried out in two stages. First, the thin copper substrate was lightly oxidized with ammonium persulfate in an alkaline environment, then incubated at 200oC for 3 hours to form copper nanowires that exist stably on the substrate surface. Immediately afterward, highly uniform CuO/Au nanowires were formed by the chemical reduction of HAuCl4 on the surface of the oxidized copper plate. The results show that gold nanoparticles of about 5 nm were attached to CuO nanowires with a length of up to 10 µm and a diameter between 100 and 300 nm. The X-ray energy dispersive spectrum demonstrated a uniform distribution of gold particles. The CuO/Au structure was used as a SERS substrate to detect methylene blue at a low concentration of 10 pM corresponding to 2 signals at the peaks 1395 cm−1 and 1625 cm−1 as the C-H and C-C deformation vibrations of the aromatic ring. The logarithms of the methylene blue concentrations were linearly proportional to their SERS signal intensity of methylene blue at the peak of 1625 cm-1 with a value R2 = 0.96. The signals of SERS for methylene blue at twelve different points on the material sample showed no significant differences in both intensity and shape of the spectrum, with an RSD value of 5.9%.

Effect of different surface roughening treatment on polyether ether ketone and acrylic resin bonding: A pilot study.

As polyether ether ketone (PEEK) is a relatively new material in dentistry, its bonding properties with regard to dental acrylic base materials are not fully known. To ensure the long-term success of removable dentures with a PEEK framework, the base materials must be well bonded to each other. The study aimed to investigate the effects of different kinds of surface roughening treatment on PEEK and acrylic resin bonding. Eighty PEEK specimens (N = 80) were randomly divided into 5 groups (n = 16 per group) and subjected to various surface roughening treatment (control, grinding, sandblasting, tribochemical silica coating (CoJet), and sulfuric acid etching). Heat-polymerized acrylic resin was applied to the treated surfaces of the PEEK specimens. The shear bond strength (SBS) test, environmental scanning electron microscopy (ESEM) analysis and three-dimensional (3D) surface topography analysis were performed. The statistical analysis of the data was conducted using the analysis of variance (ANOVA) and Tukey's multiple comparison test. The one-way ANOVA showed significant differences in the SBS values between the groups (p = 0.001). Sandblasting, tribochemical silica coating and sulfuric acid etching resulted in high SBS values (p = 0.001). The highest SBS values were observed in the sulfuric acid etching group (8.83 ±3.63 MPa), while the lowest SBS values were observed in the control group (3.33 ±2.50 MPa). The additional roughening treatment applied to the PEEK surface increases the bond strength with heat-polymerized acrylic resin.

Shrinkage Porosity Model for Steel Ingots with Reduction Deformation during Solidification

This article studies the shrinkage porosity model for steel ingots with reduction deformation during solidification, and examines the effect of reduction deformation on the shrinkage porosity. Initial investigations involve conducting experiments on reduction deformation during steel ingot solidification, entailing laboratory‐based high‐temperature melting and jack reduction process, with a focus on diverse reduction amounts and cooling times before reduction. Post‐experimental procedures include sample sectioning, acid etching, and low‐magnification structural analysis. Following this, numerical simulations are employed to model the solidification and reduction deformation processes of the steel ingot. Ultimately, a shrinkage porosity criterion model is developed, integrating the equivalent plastic strain resulting from reduction deformation during solidification into the micro‐porosity criterion model. This approach facilitates the prediction of micro‐porosity distribution following reduction deformation. Findings reveal that the shrinkage porosity criterion G2L−5/3ε/εa, which includes the equivalent plastic strain coefficient, effectively predicts the distribution of micro‐porosity subsequent to reduction deformation during steel ingot solidification. A higher reduction amount during the solidification process corresponds to a lowered level of internal micro‐porosity.

Acid etching post-treatment enhanced fungal sterilization performance of copper-manganese-cerium oxide in liquid and aerosol: Materials and molecular biological mechanisms

Bioaerosol is one of the main ways to spread respiratory infectious diseases. In order to further improve the sterilization efficiency of copper-manganese-cerium oxide (CuMnCeOx), the post-treatment method based on acid etching was adopted. The results showed that sterilization efficiency of the treated CuMnCeOx could reach 99% in aerosol with space velocity of 1400 h−1. L(+)-ascorbic acid successfully promoted the formation of Cu+, oxygen vacancies and the generation of reactive oxygen species (ROS) on the surface of the treated CuMnCeOx. During sterilization in liquid system, the transcriptome identified 316 differentially expressed genes, including 270 up-regulated genes and 46 down-regulated genes. Differentially expressed genes were significantly enriched in cell wall (GO:0005618) and external encapsulating structure (GO:0030312). Up-regulated genes were shown in regulation of reactive oxygen species biosynthetic processes (GO:1903409, GO:1903426, GO:1903428) and positive regulation all of reactive oxygen species metabolic process (GO:2000379), indicating that ROS induced cell death by destroying cell wall.

Significantly enhanced photocatalytic performance of the W-Zr-MOF-NH2@TpTt-COF heterostructure for tetracycline removal by defects engineering

A hollow heterojunction of W-Zr-MOF-NH2@TpTt-COF (WZT) was fabricated by combining etched W-Zr-MOF-NH2 with TpTt-COF. WZT, synthesized through acid etching and hydrothermal methods, showed better tetracycline degradation than pure W-Zr-MOF-NH2 and pure TpTt-COF due to its larger specific surface area and more active sites. The surface of WZT contains abundant oxygen vacancies (OVs) that capture electrons, promoting the separation of photogenerated e--h+ pairs and increasing WZT’s photocatalytic activity. WZT (1:1, mass) showed 87% degradation of tetracycline under 300 W Xenon lamp irradiation. The results of cycling experiments demonstrated the high stability and reusability of WZT (1:1), making it feasible for production. The excellent photocatalytic degradation of tetracycline by WZT (1:1) originates from the formation of heterojunctions and the presence of surface OVs, which reduces the strong photogenerated e--h+ complexation efficiency. Possible photocatalytic degradation mechanisms are proposed while demonstrating the formation of Z-scheme heterojunction in WZT, which aligned with the experimental results of electron spin resonance (ESR). The tetracycline oxidative decomposition process involves the participation of •OH, 1O2, •O2-, e-, and h+ as proven by ESR and radical trapping experiments. This work proposes a research idea to prepare high-performance photocatalysts with MOF@COF type, featuring OVs-rich and Z-scheme heterojunctions.

Design and Analysis of a Textured Cu-Encapsulated Ni Tube for Low-Reflection Electromagnetic Interference Shielding Material.

With the frequent increase and update of electromagnetic interference (EMI) shielding materials, a low-resolution material that can absorb most electromagnetic waves, thereby effectively reducing the secondary pollution, is urgently needed. However, the excellent performance, flexibility, and low cost of these methods are usually incompatible with current reports. To address the above dilemma, we reported a facile solution for fabricating a low-reflection and high-performance EMI shielding composite by means of electroless nickel plating (EP-Ni), electroless copper plating (EP-Cu), annealing, and coating with a polydimethylsiloxane (PDMS) polymer with the structure of a Ni@Cu tube encapsulated with PDMS. The results indicate that the active groups on vegetable wool can act as active sites for the absorption of the Pd catalyst, thereby catalyzing the reduction of Ni2+, Cu2+, and the subsequent deposition on the plant fiber surface. Notably, the Ni@Cu-encapsulated plant fibers decreased during annealing at 100 °C. According to the segregated network and synergistic effect of the porous structure, the as-fabricated EMI shielding material demonstrated high absorption and low reflection, in which the power coefficient of the T value was approximately 0.0001, the R value was about 0.1764 (a decrease of 27.5% compared that of EP-Ni cotton), and the A value was approximately 0.8235.

Accelerating Oxygen Electrocatalysis Kinetics on Metal-Organic Frameworks via Bond Length Optimization.

Metal-organic frameworks (MOFs) have been developed as an ideal platform for exploration of the relationship between intrinsic structure and catalytic activity, but the limited catalytic activity and stability has hampered their practical use in water splitting. Herein, we develop a bond length adjustment strategy for optimizing naphthalene-based MOFs that synthesized by acid etching Co-naphthalenedicarboxylic acid-based MOFs (donated as AE-CoNDA) to serve as efficient catalyst for water splitting. AE-CoNDA exhibits a low overpotential of 260mV to reach 10mAcm-2 and a small Tafel slope of 62mV dec-1 with excellent stability over 100h. After integrated AE-CoNDA onto BiVO4, photocurrent density of 4.3mAcm-2 is achieved at 1.23V. Experimental investigations demonstrate that the stretched Co-O bond length was found to optimize the orbitals hybridization of Co 3d and O 2p, which accounts for the fast kinetics and high activity. Theoretical calculations reveal that the stretched Co-O bond length strengthens the adsorption of oxygen-contained intermediates at the Co active sites for highly efficient water splitting.