Surface Deposition Research Articles

Coefficient Analysis of the Alluvial Fan Surface Geometry: A Methodological Approach to Applied Geomorphology

The alluvial fan is a depositional geomorphic surface at the foothills. Most of the alluvial fans in tropical regions are highly dynamic under wet climatic conditions and neotectonic environments. The fans of this region are covered with fertile top soils and deep forests. The soils attack people for agriculture in this region. Presently the continuously growing population pressure causes huge deforestation in these alluvial fan areas for cultivation which causes an accelerating rate of natural hazards like flash floods, landslides, and soil erosion that accelerate the dynamic nature of the fan surfaces. The coefficient analysis helps to understand the dynamic nature of the alluvial fan surface and thus helps to identify the hazard-prone area for planning purposes.

Damage characteristics of Cu−Cr−Zr alloy rail of electromagnetic railgun after simulated launch

The damage characteristics of different speed sections of Cu−Cr−Zr alloy rail after simulated launch were studied. The microstructure, morphologies and properties of samples were investigated by using XRD, XPS, EBSD, SEM, hardness test, electrochemical test and DSC techniques. It was found that deposition layers were formed on the surfaces of the simulated launch samples. The thickness and surface roughness of these deposition layers increased with increasing the heat effect, suggesting a launch speed dependent damage degree of the arc ablation. The hardness variation of samples is attributed to the effects of the deposition layer and deformation hardening. The surface deposition layer affects corrosion resistance and crystalline characteristics, leading to changes in subsequent service performances. Additionally, the surface texture and plastic deformation ability of the samples are related to the recrystallization degree and deformation grain amount.

High-precision inkjet 3D printing of curved multi-material structures: Morphology evolution and optimization

Multi-material printing is a significant developmental trend in the field of rapid prototyping. However, research on the simulation and prediction of multi-material formation is still at the droplet level and unable to calculate the changes in multi-material interface morphologies caused by flow and solidification. Additionally, it is not possible to predict the overall morphologies of the multi-material interfaces in a sample. Therefore, this paper proposes a multi-material morphology evolution prediction model based on convolution gradient calculations. Using semi-empirical model of multi-material droplet sliding and spreading, overlapping flow, and the multi-material droplet film solidification model, precise predictions of deposition, flow, and solidification between multiple materials were achieved and extended to curved surface deposition. Based on the prediction results, we designed an iterative optimization method for the droplet distribution and droplet grayscale to realize high-precision jet deposition, solidification, and sintering integrated forming technology for multi-material samples. This method has an interface inclination prediction error of less than 0.8° and height error of less than 10 μm, with the interface inclination approaching 0° after iterative optimization. This method can be used for the high-precision printing of devices such as antennas and metamaterials. Based on microstrip antenna printing results, the center frequency was 14.9 GHz, return loss at the center frequency was 34.22 dB, and return loss was 10 dB in the 13.6–15.4 GHz band, providing a foundation for the conformal manufacturing of high-performance multi-material electronic devices.

Architecture and dynamics of Precambrian linear megadunes: Galho do Miguel Formation, Mesoproterozoic, South-East Brazil

Recognizing the deposits of linear megadunes in ancient aeolian successions is challenging when the original bedform topography is not preserved. The present study provides a detailed analysis of the depositional architecture of an ∼ 80 m-thick interval of the Mesoproterozoic Galho do Miguel Formation (SE Brazil) to reconstruct the original morphologies of linear megadunes and to understand their dynamics. The depositional architecture reveals compound cross-bedded sets, which transition laterally into thick low-angle cross-stratified sets and planar-parallel sandstone beds. The depositional features indicate the presence of complex megadunes separated by adjoining wide dry inter-megadune areas, which were themselves flooded seasonally by a water table that rose above the depositional surface. Linear megadunes experienced two phases of development: vertical accretion and subsequent episode of lateral migration. During the vertical accretion phase, high sediment supply, typical of Precambrian aeolian systems, and the convergence of winds from two distinct directions promoted high rates of megadune growth, bedform elongation, and the formation of superimposed dunes. The lateral migration phase was characterised by a component of lateral bedform shift relative to the main along-crest sediment transport direction; this prevented preservation of a bimodal pattern of dune cross-strata azimuths. The accumulation of these deposits occurred via a combination of megadune climbing that occurred with progressive rise of the water-table level. The water-table rise hindered cannibalization of the lower parts of the migrating megadunes, allowing the accumulation and subsequent preservation of megadune sandstone packages. The rise of the water table was also responsible for the accumulation of thick dry inter-megadune strata. The unusual thickness of linear megadune and inter-megadune deposits of the Galho do Miguel Formation, as compared with Phanerozoic examples, are attributed to the interplay between the barren conditions of the early Earth, the morphodynamics of the linear megadunes, and the seasonal impact of the water table at the accumulation surface. Without a water-table control, opportunities for megadune accumulation and preservation were likely limited in Precambrian ergs.

Effect of Heat Treatment on Chemical Plating of Ni-Cr-P on 65Mn Alloy Steel

The chemical plating of Ni-Cr-P significantly affects the improvement of the structure and characteristics of the metal surface. This study aimed to investigate the impact of various plating solution components and process parameters on the deposition rate and surface hardness of Ni-Cr-P coatings on 65Mn alloy steel. Additionally, the study examined the changes in coating properties resulting from different heat treatment temperatures. The specimens coated with Ni-Cr-P underwent heat treatment at temperatures of 180°C, 200°C, 220°C, and 240°C, respectively. The testing results indicate that the plating layer achieves its highest level of performance when subjected to a heat treatment temperature of 200°C. The heat-treated coating exhibits superior wear and corrosion resistance compared to the 65Mn steel substrate. Additionally, the coefficient of friction decreases from 0.5 to 0.4. The self-corrosion potential shifts positively from -569 mV to -389 mV, and the corrosion current decreases from 61.4 μA to 14.48 μA. Furthermore, the impedance improves from 234 Ω·cm2 to 3512 Ω·cm2.

NiCo2V2O8@NC Spheres with Mesoporous Yolk- Bilayer Hierarchical Structure for Enhanced Lithium Storage.

Metal vanadates as negative electrode materials for lithium-ion batteries have attracted widespread attention, attributed to their substantial capacity, broad availability, and exceptional safety. In this study, NiCo2V2O8@NC microspheres featuring a yolk-double shell structure were successfully synthesized via ion exchange reactions and surface deposition techniques, employing metal glycerolate as a template. Owing to the bimetallic cobalt-nickel synergistic effect and the N-doped carbon network, this configuration not only optimizes the pore structure but also enhances conductivity, thereby augmenting the stability of the overall structure. The unique yolk-double shell design significantly enhances the utilization of active components and reduces the ion transport distance, thereby achieving high capacity. Thanks to the synergistic effects of this bimetallic and intricate structure, the material demonstrates exceptional capacity and cycle stability in lithium storage. The initial discharge capacity possesses 1522 mAh g-1 at a current density of 0.2 A g-1, with the reversible capacity still maintained at 1197 mAh g-1 after 100 cycles. In addition, at a high current density of 0.5 A g-1, the initial discharge capacity is 1487 mAh g-1, with a reversible capacity of 747 mAh g-1 maintained after 500 cycles. This study offers a perspective and methodology for the design and fabrication of complex porous double shell nanostructures.

Origin of ice in the Medusae Fossae Formation, equatorial Mars

We assess and test the recent radar-sounding findings of huge, kms-thick quantities of ice along the equatorial region of Mars covered by a thick protective cap (the Medusae Fossae Formation (MFF); Watters et al., 2024), using 1) atmospheric general circulation models (GCMs), 2) glacial ice accumulation and flow models, and 3) models for ice ablation-induced accumulation residues. Our results indicate that under Hesperian-era conditions, Mars at ∼40° spin-axis obliquity is predicted to accumulate snow/ice in excess of a km in less than a few million years in the MFF region, producing cold-based glaciers with basal melting over <7% of the deposit. We find that subsequent ablation of this ice deposit surface in the several billion year-long Amazonian during periods of episodic eolian stripping of MFF protective sublimation residues and dust/tephra deposits, provides a mechanism sufficient to form the thick capping layer. Similar, shorter-duration obliquity excursions during this period may have also contributed additional ice-sublation residue layers, consistent with the complex stratigraphy of the MFF. On the basis of the estimated non-ice component of the MFF ice deposit, we suggest that ablation alone could have formed the cap unit in a minimum of ∼350 million years, but was likely to have been episodic, operating in concert with periods of eolian surface lag removal over a much longer time period. The tripartite subdivision of MFF stratigraphy could indicate major periods of Amazonian obliquity excursions that deposited and removed thinner layers of ice and sublimation residue. The very high abundance of non-esker-like fluvial channels in part of the Lower Member of the MFF, combined with the paucity of ice-sheet basal melting in our analysis, suggests that ablation processes were sometimes dominated by top-down ice heating, melting and fluvial runoff. In summary, our three-part modeling approach supports the new findings, and offers new dimensions for the further analysis of the enigmatic MFF.

Sintering parameter optimization by inverse analysis in direct metal deposition of Inconel 718

PurposeThe net power delivered to the surface of parts (i.e. the actual heat flux) is a key parameter in the laser melting process and its exact control has a great impact on the numerical solutions. In this paper, the impact of laser additive manufacturing parameters including laser power, scanning speed and powder injection rate on thermal efficiency, net power delivered to the part and power loss due to powder flow has been investigated.Design/methodology/approachThe response surface method was applied to measure the net laser power in laser deposited Inconel 718 using k-type thermocouples. The temperature history obtained by thermocouples was used to calculate the net power delivered by inverse analysis method. The applied model is Rosenthal's optimized model, in which all the thermal properties of the material are considered to vary with temperature.FindingsThe results indicated that the thermal efficiency, power delivered to the part and power loss can be optimized simultaneously at laser power of 400 W, scanning speed of 2 mm/s and powder injection rate of 200 mg/s. The microstructure analysis indicated that a high-quality sample without microstructural defects was formed under optimal condition of parameters. Moreover, the primary dendrite arm spacing for the optimal sample was higher than that obtained for other samples.Originality/valueThe novelty of this research summarized as follows: Prediction of the thermal efficiency and power loss during the laser metal deposition of Inconel 718 superalloy using the inverse analysis. Finding the optimal values of thermal efficiency, power delivered to the surface and power loss in the laser metal deposition of Inconel 718 superalloy. Investigating the effect of laser power, powder injection rate and scanning speed on the thermal efficiency and power loss of Inconel 718 superalloy during the laser metal deposition.

Effect of nanodiamonds surface deposition on hydrophilicity, bulk degradation and in-vitro cell adhesion of 3D-printed polycaprolactone scaffolds for bone tissue engineering

This study was designed to deposit nanodiamonds (NDs) on 3D-printed poly-ϵ-caprolactone (PCL) scaffolds and evaluate their effect on the surface topography, hydrophilicity, degradation, andin-vitrocell adhesion compared to untreated PCL scaffolds. The PCL scaffold specimens were 3D-printed by fused deposition modeling (FDM) technique with specific porosity parameters. The 3D-printed specimens' surfaces were modified by NDs deposition followed by oxygen plasma post-treatment using a plasma focus device and a non-thermal atmospheric plasma jet, respectively. Specimens were evaluated through morphological characterization by field emission scanning electron microscope (FESEM), microstructure characterization by Raman spectroscopy, chemical characterization by Fourier transform infrared (FTIR) spectroscopy, hydrophilicity degree by contact angle and water uptake measurements, andin-vitrodegradation measurements (n= 6). In addition,in-vitrobone marrow mesenchymal stem cells adhesion was evaluated quantitatively by confocal microscopy and qualitatively by FESEM at different time intervals after cell seeding (n= 6). The statistical significance level was set atp⩽ 0.05. The FESEM micrographs, the Raman, and FTIR spectra confirmed the successful surface deposition of NDs on scaffold specimens. The NDs treated specimens showed nano-scale features distributed homogeneously across the surface compared to the untreated ones. Also, the NDs treated specimens revealed a statistically significant smaller contact angle (17.45 ± 1.34 degrees), higher water uptake percentage after 24 h immersion in phosphate buffer saline (PBS) (21.56% ± 1.73), and higher degradation rate after six months of immersion in PBS (43.92 ± 0.77%). Moreover, enhanced cell adhesion at all different time intervals was observed in NDs treated specimens with higher nuclei area fraction percentage (69.87 ± 3.97%) compared to the untreated specimens (11.46 ± 1.34%). Surface deposition of NDs with oxygen-containing functional groups on 3D-printed PCL scaffolds increased their hydrophilicity and degradation rate with significant enhancement of thein-vitrocell adhesion compared to untreated PCL scaffolds.

Effect of Flow Velocity on Clogging Induced by Coal Fines in Saturated Proppant Packs: A Transition from Surface Deposition to Bridging.

Hydraulic fracturing is a widely used technique to enhance the production of coalbed methane reservoirs. However, a common issue is the invasion of coal fines into proppant packs, leading to pore clogging and reduced conductivity. This study investigated the impact of flow velocity on clogging by coal fines in saturated proppant packs to optimize the flow velocity and alleviate clogging during dewatering. Clogging experiments induced by coal fines were conducted on saturated proppant packs with varying superficial velocities. Throughout each experiment, the permeability and effluent concentration were monitored, and the process of clogging was visually observed using an optical microscope. The experimental results showed that both permeability and effluent concentration initially increased and then decreased with an increase in flow velocity, indicating the existence of a critical flow velocity for minimizing clogging in proppant packs. Microscale observations revealed that the dominant regimes of clogging induced by coal fines at low and high flow velocities were surface deposition and hydrodynamic bridging, respectively; a critical flow velocity was required to induce the occurrence of bridging. Removal efficiencies of coal fines in relation to surface deposition and straining against flow velocity were theoretically analyzed, aiming to provide insights into the mechanisms underlying the impact of flow velocity on clogging. The results showed that the overall removal efficiency by surface deposition and straining decreased with an increase in flow velocity. Theoretical data matched well with the experimental results at low flow velocities but failed to explain the outcomes at high flow velocities, primarily due to the onset of bridging at high flow velocities. This study highlights the necessity of developing a removal efficiency model for bridging to accurately describe clogging by coal fines in proppant packs and provides recommendations for clogging control in proppant packs.

A Study of the EH36 Surface Sediment Layer under Joint Protection from Seawater Electrolysis Antifouling and Impressed Current Cathode Protection (ICCP) in a Marine Environment

A joint protection device for seawater electrolysis antifouling and ICCP was constructed, and comparative experiments were conducted to study the composition of the EH36 surface deposition layer under joint protection in a marine environment. Surface morphology analysis, energy-dispersive spectroscopy (EDS) imaging analysis, and X-ray diffraction (XRD) composition analysis were performed on the surface deposition layers of the experimental samples. The experimental results showed that under joint protection, a sedimentary layer was rapidly formed on the surface of EH36 to isolate the seawater medium, and this layer was mainly composed of Mg(OH)2 and a small amount of CaCO3. There was no corrosion on the surface of the EH36 substrate. When only ICCP was used, a relatively thin layer of calcium magnesium was deposited on the surface of EH36. Marine fouling organisms adhere to the surface of calcium and magnesium sedimentary layers and the EH36 substrate, and their attachment affects the formation of calcium and magnesium sedimentary layers. Moreover, marine fouling organisms cause corrosion on the surface of the EH36 substrate. The joint protection of seawater electrolysis antifouling and ICCP can simultaneously prevent electrochemical corrosion and marine biological fouling corrosion on the surface of EH36.

Систематизация рабочих органов машин глубокого фрезерования

Currently, ensuring energy security is a key priority for the country. Peat resources account for one-third of the country's total energy potential. Apart from energy production, peat finds extensive use in agriculture, chemical industry, construction, and the production of construction materials. Presently, milled peat constitutes the main volume of production in the country. The technology of its extraction involves preparing areas and removing undergrowth, stumps, and wood debris during preparation of the deposit by trenching or deep milling. However, due to the imperfections of the equipment, peat contamination and loss of its quality occur. This article analyzes means for carrying out preparatory operations to condition the surface of the deposit. It discusses the designs of end effectors for deep milling machines, their cutting structures, and the specific features of the tools used, i.e. blades, cutters, mills, chains. Classification of end effectors for peat machines as well as tools for deep milling of the deposit surface is proposed. This systematization involves identifying classification features by the type of machines, impact on the wood debris, movement of the end effector, its arrangement and design, as well as by parameters and types of the end effector’s cutting structures. The article may be useful for engineers, researchers, graduate students, and organizations involved in designing and studying processes of peat deposits conditioning.

Long-Term Prevention of Biofilm Formation by Polycatechol-Based Supramolecular Assemblies with Low Molecular Weight Polymers on Surfaces.

Achievement of a stable surface coating with long-term resistance to biofilm formation remains a challenge. Catechol-based polymerization chemistry and surface deposition are used as tools for surface modification of diverse materials. However, the control of surface deposition of the coating, surface coverage, coating properties, and long-term protection against biofilm formation remain to be solved. We report a new approach based on supramolecular assembly to generate long-acting antibiofilm coating. Here, we utilized catechol chemistry in combination with low molecular weight amphiphilic polymers for the generation of such coatings. Screening studies with diverse low molecular weight (LMW) polymers and different catechols are utilized to identify lead compositions, which resulted in a thick coating with high surface coverage, smoothness, and antibiofilm activity. We have identified that small supramolecular assemblies (∼10 nm) formed from a combination of polydopamine and LMW poly(N-vinyl caprolactam) (PVCL) resulted in relatively thick coating (∼300 nm) with excellent surface coverage in comparison to other polymers and catechol combinations. The coating properties, such as thickness (10-300 nm) and surface hydrophilicity (with water contact angle: 20-60°), are readily controlled. The optimal coating composition showed excellent antibiofilm properties with long-term (>28 days) antibiofilm activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) strains. We further utilized the combination of optimal binary coating with silver to generate a coating with sustained release of silver ions, resulting in killing both adhered and planktonic bacteria and preventing long-term surface bacterial colonization. The new coating method utilizing LMW polymers opens a new avenue for the development of a novel class of thick, long-acting antibiofilm coatings.

Decoupling study on the influence of the interaction between biomass hydrochar and coal during co-pyrolysis on the char structure evolution

Co-pyrolysis of biomass hydrochar (biomass processed by hydrothermal carbonization, HTC) and coal, is a viable method for the clean and high-efficiency co-utilization of conventional and renewable resources. Interaction between biomass hydrochar and coal during co-pyrolysis directly impacted the physiochemical structure evolution of char and its downstream application. However, interaction mechanism hasn't been systematically revealed till now. Therefore, this study conducted a decoupling investigation on co-pyrolysis of rice straw hydrochar (RSH) prepared at different HTC conditions and bituminous coal (BC) using a staged fixed-bed reactor. The results demonstrated that RSH volatiles increased the number of deposits and cracks formed on the surface of co-pyrolysis decoupled BC char. Additionally, volatiles from RSH prepared at higher HTC temperatures led to the decrease of surface deposits, surface functional groups (such as –OH, C–H, and C–O) and graphitization degree of BC char. However, volatiles prepared at different solid-liquid ratios had a negligible impact on physicochemical structure of BC char. At HTC temperature of 200 °C, volatiles from BC led to increased surface functional groups (such as –OH and CC) and graphitization degree of co-pyrolysis decoupled RSH char. Furthermore, volatiles from BC showed more noticeable effect on graphitization process of RSH char prepared at higher solid-liquid ratio.

Patterns and controls of topographic change within the deflation basins of a trough and bowl coastal blowout

AbstractIn North‐West Europe and throughout the world, dune systems are increasingly stabilised by vegetation, due to both human intervention and changes in climate. Blowouts are erosional hollows produced by wind erosion in vegetated or semi‐vegetated dune systems. Where active blowouts are present in vegetated dunes, they provide a source of dynamism and sediment in an otherwise fixed environment. The transition from a fixed vegetated dune to an active blowout is poorly understood, however, and anthropogenic attempts to reactivate areas of bare sand in dunes are often unsuccessful. In this study, we measured topographic change at a monthly resolution in the deflation basins of one bowl and one trough blowout over a 23‐month period in Ainsdale Sand Dunes National Nature Reserve, North‐West England. Our results show that monthly surface change in the blowouts did not correlate strongly with the transport capacity of winds measured at a meteorological station 10 km south of the site. Precipitation was found to have a moderate negative correlation with all indices of surface change, that is, the more it rained the less the surface changed. Inter‐annual (23 months) patterns of topographic change in the bowl and trough blowouts were distinctly different. In the deflation basin of the bowl blowout erosion predominantly took place on the erosional walls facing into the prevailing winds, while minimal change occurred on the erosional walls facing away from the prevailing wind direction. This produced a moderate negative correlation between surface change and slope, that is, the steeper the slope, the more erosion occurred. In the trough blowout, erosion took place in the centre of the deflation basin and minimal change was measured on the easternmost erosional wall, which faced the prevailing winds. Patterns of monthly topographic change were highly variable and demonstrated that changes in the direction of above‐threshold winds can cause blowout walls and floors to ‘flip’ from erosional to depositional surfaces. These findings highlight the variability and complexity of surface change in blowouts and demonstrate that patterns vary because of landform morphology and climatic conditions.

Generation of nano-to-microplastics from polypropylene surfaces via femtosecond laser ablation in liquids with different viscosities

Preparation of polypropylene (PP) nano and microparticles, crucial for investigating the effects of plastics on both human health and the environment, presents a significant and immediate challenge. Utilizing an fs laser system in different liquid mediums such as water, dodecane, and hexadecane, we have successfully generated PP particles with sizes ranging from 1.8 to 4911 nm. This outcome is partly attributed to the constraint on plasma expansion caused by the viscosity of the liquid media. We investigated the areas of material removal and observed a transition from ordered to disordered removal patterns during this process. The formation of filaments and pillars within the material removal cavity, along with the deposition layer at the cavity edge, primarily occurred due to insufficient plasma formation at low laser energy levels. Furthermore, we observed neck-shaped filaments and nano cracks on the deposition surface, which were attributed to the heat effect during laser interaction with the PP substrate. Moreover, we collected distinct nano-Fourier transform infrared spectroscopy (FTIR) signals from both the nanoparticle area and the deposition layer, revealing a 2 cm−1 wavenumber difference between the two regions. This discrepancy proved to be a valuable method for distinguishing between the nanoparticle area and the deposition layer.

Evidence for polyimide redeposition and possible correlation with sparks in Gas Electron Multipliers working in CF[formula omitted] mixtures

Research on aging processes of Gas Electron Multipliers (GEMs) is important to obtain insights on how to increase the detector’s longevity, stability, and performance, as highlighted in the latest developments roadmap by the European Council of Future Accelerators (ECFA). One key aspect of the aging process is the deposit formation on the electrodes surfaces. In this work, through the analysis of the molecular content on the surface of a used GEM, we provide evidence for polyimide redeposition as a source of organic material contributing to the formation of insulating layers on the electrodes, which eventually lead to sparks and detector failure. Furthermore, we show that chromium, used to promote adhesion between copper and polyimide, in the device undergoes a diffusion process, effectively blurring the layered structure. We demonstrate the significance of surface-sensitive chemical analysis to investigate the surface deposits on electrodes of gaseous detectors and our results reveal the necessity of standardization and more stringent study protocols.

Molecular dynamics simulations and analyzation of Cu deposited on stainless steel substrate surfaces

Copper (Cu) is used in integrated circuits and microdevices and has the potential to replace aluminum alloys due to its low resistivity, strong electromigration properties, and affordability. However, a significant factor that influences the performance of devices at the micro and nano scales is the surface roughness of the deposits. LAMMPS software is employed to simulate the deposition Cu on an ideal state for a stainless-steel substrate. The deposition process and deformation behavior of Cu on the surface and the roughness of the deposition surface are analyzed. Taking the deposition process of Cu atoms as an object, the effects of different atomic numbers, different temperatures, different velocities, and different heights on the surface roughness of the deposits were investigated. The atomic structure composition of the deposition velocity is analyzed, and the radial distribution function is analyzed to reveal the microscopic mechanism of action. The results of the theoretical deposition and analysis show that the surface roughness increases with the number of atoms deposited and decreases with increasing substrate temperature. The surface roughness first decreases and then, after some fluctuation, stays constant at a particular level with increasing velocity. Additionally, as the deposition height increases, the surface roughness reduces. There is a nonlinear relationship between the various components and the deposited surface roughness. The surface quality of deposits can be improved during the deposition process by optimizing the deposition parameters of deposition atoms, substrate temperature, deposition velocity, and deposition height.

Electrophoretic Deposition and Characterization of Curcumin/Chitosan Coatings

The purpose of the study was to investigate the electrophoretic deposition (EPD) route, microstructure and surface properties of composite curcumin/chitosan coatings on commercially pure titanium substrates for biomedical applications. Multiple routes of preparation of the dispersed systems for the EPD process and their electrokinetic properties have been investigated to obtain homogeneous coatings. The zeta potential of solutions with various curcumin content in ethanol or isopropanol proved their relatively low electrophoretic mobility. Thus, curcumin was co-deposited with chitosan molecules on the cathode. The surface morphology of the coatings consisted of submicrometric curcumin particles embedded in the chitosan matrix. The increase in the curcumin content in the ethanol caused large agglomerates and undissolved curcumin particles to appear on the coating surface. The coatings were characterized by high adhesion to the substrate and a water contact angle in the range of 85° to 95°. The coatings changed the zeta potential of the titanium surface from significantly negative (−46.7 ± 2.3 mV) to less negative values (−20.6 ± 2.6 mV). The developed coatings are promising for mitigating biofilm formation on the surface of titanium bone implants.

MXene and polyaniline coated 3D-printed carbon electrode for asymmetric supercapacitor

ABSTRACT 3D printing has emerged as an attractive manufacturing technique in supercapacitor electrodes owing to the precise and customisable fabrication of complex electrode designs, enhancing the performance and efficiency of the device. Despite the advantages, 3D-printed electrodes are limited by their low conductivity and electrochemical properties, predominantly due to the lack of availability of suitable conductive materials. To address this limitation, we modified the 3D-printed nanocarbon (3D-PnC) electrode by activation and surface deposition of Ti3C2Tx MXene. A solid-state asymmetric supercapacitor was fabricated by using 3D-PnC/Ti3C2Tx as the negative electrode and polyaniline (PANI) electrodeposited 3D-printed nanocarbon electrode (3D-PnC@PANI) as the positive electrode. The fabricated symmetric supercapacitor exhibits enhancement in overall voltage window, areal capacitance and energy density. The successful operation of the supercapacitor was demonstrated by the illumination of the red light-emitting diodes. Furthermore, this research opens the possibility of utilising MXene-modified 3D-printed electrodes for various electrochemical applications and devices.