Smooth Surface Research Articles

Effect of Rice Biochar on Typical Cadmium, Lead and Zinc Form in Contaminated Soil in Northwest Guizhou Province, China

This study was conducted in Hezhang County, Bijie City, Guizhou Province. The soil in the zinc smelting area has been contaminated with cadmium, lead, and zinc. Therefore, these elements are the focus of this research. Rice husk biochar was used as the passivation material. The Fourier infrared spectrum was utilized to study the biochar’s morphology, element content, mineral composition, structure, and surface functional groups. Moreover, the physical and chemical properties of the biochar were analyzed to explore its passivation effect. Biochar is beneficial in the cleaning of cadmium, lead, and zinc minerals and can be used for the passivation of heavy metals in contaminated soil. This study aims to understand the detailed mechanism behind this process and provide experimental data and ideas for pollution control. The results indicate that the biochar contains many functional groups, including -OH, C-H, C-O, C=O, C=C, and C-O-C. It also consists of a significant quantity of potassium salt, calcite, and quartz. Biochar has a noticeable pore structure, and as the pyrolysis temperature increases, the pore structure becomes more developed and thinner, with a smooth surface. The main minerals in the soil are quartz, mica, zeolite, illite, and chlorite. The aromatic degree of biochar increased with pyrolysis temperature. In contrast, the aromatic degree and polarity first increased and then decreased. The 0.2-0.45 mm biochar exhibited the best passivation effect on cadmium, lead, and zinc.

Analysis of Damage to Main Bearing on The Diesel Generator Motors at KM Sabuk Nusantara 89

Main bearings are made from special metal materials that are resistant to hot engine friction. The main bearing has holes in several parts which function to allow fluid (lubricating oil) to flow. Metal sitting is two plates that have a very smooth surface and consist of several layers of metal that have different hardness. The main bearing is a very vital part to support the performance of the crankshaft. The aim of this research is to determine the factors that cause damage to main bearings in diesel generator motors. The research method used is a qualitative descriptive method using observation, interviews and documentation methods and using the fishbone analysis method. The results obtained from this research show that the causes of damaged main bearings in diesel generator motors are decreased lubricating oil pressure, lack of understanding of maintenance procedures and fatigue of the seated metal component materials.

Intelligent locust bean gum-k-carrageenan nanofibrous mats with Rosa canina petal anthocyanins and chitosan nanoparticles: Preparation, characterization, and application for monitoring of beef meat freshness

The objectives of the present experiment were to add Rosa canina petal extract (RCE, 3.5%) and chitosan nanoparticles (CNP, 1.5%) into the locust bean gum-kappa-carrageenan (LBG-KC) nanofiber mats and to examine their utilization for the freshness tracking of beef meat during the 6-day storage period. The surface morphology analysis of nanofibers using the scanning electron microscope showed that all developed nanofibers were cylindrical, uniformly disordered network structures with smooth surfaces. The tensile strength, elongation at break, water vapor permeability, water solubility, and moisture content of RCE/CNP-loaded nanofiber mats were recorded to be 10.00–31.77 MPa, 16.55%–22.98%, 5.04–9.18 × 10‾5 g mm/m2 h Pa, 3.80%–10.08%, and 2.10%–4.89%, respectively. The LBG-KC + RCE 3.5% and LBG-KC + RCE 3.5% + CNP 1.5% nanofibers were red, dark blue, green, and brown at pH values 1–6, 7–8, 9, and 10–12, respectively. After 4 days of beef meat storage at refrigerated conditions, the total viable count, pH, and total volatile basic nitrogen were 7.24 log CFU/g, 7.11, and 28.89 mg N/100 g, respectively. Moreover, on the 0th day, the pH-sensitive indicators presented a white color and after 4 days of meat storage, the indicator color changed to dark blue, which could indicate beef meat spoilage.

OCT-based comparative evaluation of culprit lesion morphology in very young versus older adult patients with STEMI.

The clinical and pathophysiological characteristics of coronary artery disease in very young adults are poorly described. Using optical coherence tomography (OCT), we compared culprit lesion morphology in very young adult patients (≤35 years) versus older adult patients (>60 years) with ST-segment elevation myocardial infarction (STEMI). Culprit lesion morphology was classified as plaque rupture, plaque erosion, or calcified nodule. Thrombus age was subclassified into acute (intraluminal thrombus with surface irregularity) or subacute (mostly mural thrombus with a smooth surface). A total of 61 patients who underwent thrombolysis within 24 hours from symptom onset were included, with 38 (59.7%) subjects ≤35 years and 23 (40.3%) subjects >60 years of age. As an underlying mechanism of STEMI thrombosis, plaque erosion was more common in very young patients (52.6% vs 21.7%; p=0.02) while plaque rupture was more common in elderly patients (65.2% vs 36.8%; p=0.03). Acute or subacute thrombus was identified in 68.9% (42/61) of patients, with red thrombus being more frequent in very young patients. In the entire patient cohort, acute thrombus was more frequent in plaque rupture compared with plaque erosion (62.0% vs 28.0%; p=0.01), whereas subacute thrombus was more common in plaque erosion versus plaque rupture (52.0% vs 10.3%; p=0.0008). OCT showed that plaque erosion and plaque rupture were the most common underlying STEMI mechanisms in very young patients and older patients, respectively, and that subjects with plaque erosion had greater evidence of subacute thrombus.

Comparative studies on pinhole free CBD-CdZnS thin films on ITO and FTO substrate

The development of CdZnS thin films using the chemical bath deposition process in nonaqueous media is a technological challenge. In this work, 75 millilitres of ethylene glycol and ethanol (1:2 ratios) were used to develop a CdZnS thin film on ITO and FTO glass substrates using cadmium acetate, zinc sulphate, and thiourea. The ideal bath temperature was kept at 1300C and the anneal temperature of the film that had been deposited in the air was maintained at 3500C. The films have been examined using FTIR, WCA, FESEM, and XRD. XRD studies reveal that CdZnS films have a hexagonal crystal structure with a preference for orientation (002) during the deposition and annealing processes and the assessment of the various attributes have been done, such as dislocation density, micro strain, and grain size. FESEM study indicates that as deposited film on ITO glass have smooth surface and grains appear in the form of small needle shape of equal sizes where as FTO substrate reveals the grains of equal size throughout the entire surface in cluster form. It is also confirmed that both the CdZnS films formed on ITO and FTO substrates have hydrophilic quality. The presence of chemical bonds and functional groups was confirmed by FTIR analysis.

Effect of blade geometry on the powder spreading process in additive manufacturing

In powder-bed-based additive manufacturing, the quality of the powder bed is closely related to the geometry of the blade used during the powder spreading process. In this study, the spreading process with the vertical blade, inclined blade, and round blade with different radii was performed by discrete element method to investigate the effects of blade geometry on powder spreading. The results show that at the same spreading parameters, the round blade caused the highest density than inclined blade and vertical blade. Increasing the round blade radius can improve the packing density of the powder bed, but it has little effect on the uniformity. The increase in packing density is related to the transitional smoothness of the blade surface at the entrance of the powder bed. The smoother the shape transition of the blade surface at the powder bed entrance, the powders enter the powder bed more gently, so more powders enter the powder bed, resulting in higher packing density. The results may provide suggestions for improving the laser melting process.

Synthesis and characterization of Fe3O4@SiO2 core-shell nanoparticles for mirror and efficient magnetic compound fluid polishing of TC4 titanium alloy

To fully investigate the polishing performance of the Fe3O4@SiO2 core–shell abrasive for TC4 titanium alloy plate and solve the problem of uneven distribution of abrasive particles in magnetic compound fluid polishing (MCFP) and obtain ultra-smooth titanium alloy surface. In this paper, the functional Fe3O4@SiO2 core–shell abrasives were prepared and characterized by XRD, FTIR, VSM and TEM to demonstrate the successful encapsulation of SiO2 in Fe3O4 first. Second, a new polishing device was built to perform polishing experiments. Four different fractions of Magnetic compound fluid (MCF) were configured and utilized in polishing experiments for MCFP of TC4 titanium alloy to verify the polishing properties. Finally, the contact model between abrasive particles and workpiece is established and the material removal mechanism is discussed. The results show that SiO2 was successfully coated on Fe3O4. The polishing results show that the MCF containing the core–shell structure had the best polishing effect. The surface roughness Ra decreased from 0.201 μm to 0.025 μm after 20 min of polishing. The surface roughness of TC4 titanium alloy with an initial roughness Sa of 0.248 μm is reduced to 0.023 μm after polishing by Fe3O4@SiO2 core–shell abrasive. It is shown that the application of core–shell abrasive to process titanium alloys can obtain smooth and defect-free surfaces with good polishing performance. The surface quality of titanium alloy can be improved effectively by using core–shell abrasive, and a new idea for polishing titanium alloy is proposed. This study plays an important role in solving the problem of uneven particle distribution in MCFP. These results pave the way for further research into the application of core–shell abrasives in precision machining and expand the application scope of particles with core–shell structure.

Arthroscopic Debridement and Resection of a Bennett Lesion in a Collegiate Baseball Pitcher

Background: Overhead throwing athletes are predisposed to ossification along the superior to inferior posterior glenoid rim, termed thrower's exostosis or a Bennett lesion. These lesions can result in posterior shoulder pain during throwing and decreased shoulder range of motion, and they can be associated with posterior labral tears and undersurface rotator cuff tears. In this video technique, we describe the arthroscopic debridement and resection of a symptomatic unstable Bennett lesion in a collegiate baseball pitcher who had unsuccessful nonoperative treatment. Indications: Currently, there is no standard treatment algorithm for Bennett lesions. Arthroscopic intervention is typically indicated in overhead throwers who have unsuccessful nonoperative protocols, including stretching of the posterior capsule, strengthening of the rotator cuff, and injections. Technique Description: In the lateral decubitus position, standard posterior viewing and anterior working arthroscopic portals are created followed by diagnostic arthroscopy. A high anterior accessory portal is created to view the posterior labrum and evaluate for tears. The location of the Bennett lesion is determined using a switching stick or probe. In this case, an accessory posterior viewing portal and capsulotomy are created under spinal needle visualization and a 70° scope is utilized for an improved view. Through the capsulotomy, a motorized shaver and radiofrequency wand is used to work along the posterior inferior glenoid neck to expose the lesion. Once the lesion is fully demarked, a hooded bur is utilized to debride the entirety of the lesion back to the smooth bony surface of the glenoid neck. After resection, the capsule is left open to avoid overtightening the posterior capsule in overhead throwing athletes. Results: Arthroscopic debridement and resection of a symptomatic Bennett lesion in a collegiate baseball pitcher allowed the patient to return to pain-free pitching at the same level of collegiate play the following season. Discussion/Conclusion: An unstable Bennett lesion can be a source of pain in the overhead throwing athlete. If nonoperative treatment modalities fail to resolve symptoms, arthroscopic debridement and excision of this lesion utilizing a posterior capsulotomy and accessory posterior viewing portal as described in this video technique is a safe and effective surgical option. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Arthroscopic Mumford Procedure for AC Joint Arthritis

Background: Acromioclavicular (AC) joint arthritis is a common cause of shoulder pain in young patients. Management has been focused on relieving pain mainly with conservative nonsurgical procedures such as corticoid injections, physical therapy and even, recently, orthobiological interventions with platelet-rich plasma and hyaluronic acid injections. However, failed conservative management opens the door to surgical interventions such as the arthroscopic distal third of the clavicle resection. Indications: Patients submitted to this surgery must have a confirmed diagnosis of an arthritic, painful AC joint that has not been properly responding to nonoperative management. Technique Description: The surgical procedure is done in the beach chair position with standard arthroscopic portals. After a proper intraarticular evaluation of the structures and ruling out any other causes of pain, the surgeon passes to the subacromial space. Identification of the AC joint is made by following the coracoacromial ligament medial and with manipulation of the clavicle from the patient's skin. Debridement should start by releasing the anterior and posterior ligaments to allow for proper visualization of the articulation. A bur or a 5.5-mm shaver is used to start resection of the distal third of the clavicle under visualization and with care to not create a vault. The procedure is considered done when a smooth articular surface is visualized and with at least 5 mm of space between the clavicle and the acromion. Results: The proposed technique, which is a variant of the classic distal clavicle excision, has shown improved functional outcomes with reproducible postoperative scores and low complications rates in the setting of patients with isolated AC joint arthritis. Conclusion: Surgical management of the painful, arthritic AC joint has been evolving alongside with the history of shoulder arthroscopy; the proposed arthroscopic approach is an easy and effective way of freeing the patient of pain and discomfort with quick return to activities and sports. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Efficient fabrication of large-scale chalcogenide glass microlens arrays via precision molding method

Infrared microlens arrays (IR MLAs) are crucial for infrared imaging, target detection, and night vision, but creating high-quality large-scale IR MLAs is costly and challenging. This study presents a precision molding method to produce 500 × 500 microlenses on chalcogenide glass. The method involves creating concave silica molds with femtosecond laser-assisted chemical etching, which are then used to press convex MLAs onto the chalcogenide glass surface. By using single-pulse direct writing technology, a microlens array template containing 500 × 500 microlenses can be completed within 25 min. Meanwhile, the chemical etching method offers a highly efficient and low-cost way to prepare mold. The resulting MLAs exhibited smooth surfaces, uniform structures, and good imaging and focusing capabilities, indicating the effectiveness of this approach for large-scale MLA patterning and batch production.

Squeeze force of a Maxwell fluid between circular smooth surfaces with simple harmonic motion

The force and mechanical power required to maintain the simple harmonic motion (SHM) of the upper circular surface squeezing a viscoelastic fluid film is analyzed. The amplitude of the displacement of the upper surface is very small compared to the gap width as a function of time. The smoothness of the upper and lower surfaces is characterized by the slip model with two constant parameters, a slip length and a critical surface shear stress. The nonlinear convection terms in the momentum equation are neglected since the viscous forces dominate the inertial forces. The acceleration and deceleration terms are retained since the upper plate oscillates harmonically and the velocity in the fluid is strictly periodic. An exact solution of the governing equations is found as a function of the Deborah number, the Womersley number, the slip length, and the critical surface shear stress. A circular region without slip condition, bounded by a time-dependent radius, appears when the shear stress of the fluid does not exceed a critical surface shear stress. In addition, an annular region with slip up to the radius of the disk appears when the critical surface shear stress is exceeded. Our results show that viscoelastic and hydrophobic effects together with the Womersley number and a critical surface stress cause changes in the amplitude and phase lag of the waveform of the time-dependent radius and the force acting on the wall surface to maintain the SHM of the upper disk.

Chemical-mechanical synergetic effect of single crystal SiC polishing using Fe3O4@MIL-100(Fe) magnetic photo-Fenton catalyst

Achieving an atomically smooth surface on single-crystal silicon carbide (SiC) with a high material removal rate (MRR) is challenging. Traditional chemical mechanical polishing (CMP) often uses aggressive slurries that are inefficient and environmentally hazardous. To address these challenges, we synthesized a novel core-shell structure Fe3O4@MIL-100(Fe) magnetic catalyst and utilized it as a non-homogeneous photo-Fenton catalyst in friction wear tests on SiC wafers within a simulated CMP environment. The catalyst was thoroughly characterized using X-ray diffractometry (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Additionally, we explored the effects of various components, pH levels, H2O2 concentrations, catalyst concentrations, and light intensities on the friction wear of SiC wafers. The results indicate that, under visible light conditions, Fe3O4@MIL-100(Fe) exhibits a strong Fenton catalytic effect, achieving a maximum material removal rate of 61.076*103μm3/min at a pH of 3, H2O2 concentration of 5 wt%, catalyst concentration of 14 g/L, and light intensity of 500 W. These findings provide valuable theoretical support for visible light assisted catalyzed CMP of SiC.

Extraction and characterization of novel alternative cellulosic fiber for sustainable textiles from Aloe barbadensis Miller stems (agricultural waste)

Novel research has been conducted on Aloe vera, focusing on stems fiber (agricultural waste), for the extraction of cellulosic fiber, an area lacking prior scientific exploration. This fiber is being reported for the first time in the scientific community. Aloe barbadensis Miller variety was subjected to various cultivation methods, including the application of inorganic and organic fertilizers, along with the removal of lower leaves to promote stem growth. Stem fibers were extracted using the water retting method and subsequently analyzed. The moisture content was 55.35 % and 6.99 % ash content in the fibers. The bacteriostatic analysis of Aloe vera fibers was assessed against four bacterial strains, with both ethanol and water extracts showing varying degrees of inhibition zones. The UV–Visible spectrum exhibited a distinct λmax at 247 nm in ethanol, while FT-IR analysis provided characteristic peaks at 3759, 1590, 1750, 1663, 1250, 564, SEM images displayed the smooth surface morphology of the fibers, and X-ray diffraction analysis indicated a high degree of crystallinity (78.67 %), suggesting a well-structured and crystalline nature. Energy dispersive X-ray (EDX) analysis was conducted to determine the elemental composition of the fibers, revealing the presence of carbon, oxygen, calcium, and copper, with carbon being the predominant element in cellulose. These results showed promising properties suggesting potential applications in textile industry as an alternative sustainable natural cellulosic fiber.

Evaluation of hair surface structure and morphology of patients with lichen planopilaris (LPP) by atomic force microscopy (AFM).

Lichen planopilaris (LPP) is a chronic lymphocytic skin disease manifested by progressive scarring alopecia. The diagnosis of LPP is made based on histopathological examination, although it is not always definite. The current study evaluates the effectiveness of non-invasive atomic force microscopy (AFM) hair examination in detecting morphological differences between healthy and diseased hair. Here, three to five hairs from lesional skin of 10 LPP patients were collected and examined at nine locations using AFM. At least four images were taken at each of the nine sites. Metric measurements were taken and metric (length, width, and scale step height) and morphological features (striated and smooth surface of scales, the presence of endocuticle and cortex, shape of scales edges, scratches, pitting, cracks, globules, and wavy edge) were compared with hair from healthy controls. In addition, areas on diseased hair where the process of pathological, unnatural delamination of the hair fiber occurs are described. There was a statistically significant difference in the number of scratches in the initial sections of the LPP hair, in the intensity of wavy edges along the entire length of the tested hair, and in the number of scales with pitting in the middle section of the hair. In addition, a statistically significant higher number of scales with striated surface was found in LPP group starting at 3.5cm from the root continuing towards the free end of the hair. Other morphological changes such as presence of cortex, globules, oval indentations, and rod-like macrofibrillar elements were also assessed, however, detailed results are not presented, as the differences shown in the number of these morphological changes were not significantly different. This publication outlines the differences between virgin, healthy Caucasian hair, and the hair of LPP patients. The results of this study can be used for further research and work related to LPP. This is the first attempt to characterize the hair of LPP patients using AFM.

Study of Some Physical and Antibacterial Properties of Bio-based (PLA)/(PCL) Blend reinforced with ZrO2 Nanoparticles

The aim of this study was to produce flexible films by combining polylactic acid (PLA) and poly(ε-caprolactone) (PCL), and enhance their strength by reinforcing them with different weight percentages (0.75, 1.5, and 2.25%) of zirconium oxide (ZrO2) nanoparticles (NPs) using a solvent casting process. The physical and antibacterial properties of the films were analysed to determine their suitability for use in food packaging. X-ray diffraction (XRD) patterns of the PLA/PCL films containing 2.25% by weight ZrO2 nanoparticles have a peak at an angle of 2θ = 17.18°, accompanied by smaller peaks. This confirms that these thin films have a semi-crystalline structure and that the molecules in the thin films are well dispersed. Scanning electron microscopy (SEM) analysis of the film surfaces reveals that the pure PLA/PCL films exhibit a smooth surface, while the (PLA/PCL/ZrO2NPs) films have a rough surface. The thermal behaviour of the blends through differential scanning calorimetry (DSC) showed fluctuations due to variations in the reinforcement ratio, resulting in changes in the glass transition and melting temperatures. These oscillations indicate changes in the level of crystallinity. ZnO2 has antibacterial properties that promote growth inhibition, making these films more effective in food packaging.

Surface micro-welding strategy of h-BN assembled microspheres for composites with desirable thermal conductivity and a low dielectric constant

As electronic devices strive for higher integration and faster signal transmission, the demand rises for polymer composites with high thermal conductivity (TC) and low dielectric constant (εr). However, high TC composites often come with a high filler content, leading to a reduction in processibility and dielectric properties. Herein, by surface micro-welding strategy, we fabricated cohesive h-BN microspheres (SBO) with a quasi-hollow structure. The pre-constructed micro-nano network of h-BN inside the microsphere serves as a continuous pathway for heat transfer, while the internal space of the microsphere is divided into numerous gas chambers, establishing a foundation for low εr. Benefiting from this structure, the TC of the prepared composite is 2.12 W/m·K, and its εr is remarkably low at 3.24 (103 Hz), effectively balancing the TC and dielectric properties at a high filler loading. Furthermore, this designed structure significantly reduces the viscosity of the composite (measured 309 Pa s with a filler content of 50 wt% at 1s−1) due to the smooth surface of the microsphere. This strategy offers a facile approach for fabricating composites characterized by desirable TC, low εr and excellent processibility, showcasing promising prospects for advancement in the realm of microelectronics.

Exploration on the corrosion inhibition performance of Salvia miltiorrhiza extract as a green corrosion inhibitor for Q235 steel in HCl environment

Salvia Miltiorrhiza, extensively distributed and commonly employed as a traditional Chinese medicinal herb, has garnered significant attention. In this study, the Salvia Miltiorrhiza extract (SME) was prepared by one-step water extraction method, and was firstly used as a novel corrosion inhibitor for Q235 steel in 1 mol/L HCl solution. As identified via liquid chromatography-mass spectrometry, the findings reveal that Salvianic acid A, tanshinone II A, danshenxinkun D, dihydrotanshinone, and methylene tanshinquinone are the primary constituents of SME. The optimum corrosion inhibition efficiency reached 92.8 % at 200 mg/L and maintained at 90.4 % after 72 h. Based on in-situ scanning vibration electrode technology (SVET) monitoring, the adsorption of inhibitor molecules on metal surface greatly retarded the propagation of localized corrosion. AFM examination of the corroded surface reveals that the samples supplemented with SME exhibit a smoother surface compared to the blank group. The force curve graph for the SME-added group demonstrates a more evenly distributed point array and an elevated average adhesion force, indicating that the addition of SME improves the corrosion resistance of the metal surface. XPS characterization illustrated that SME interacted with iron ions to form insoluble precipitate. This work investigated the application of SME as an eco-friendly corrosion inhibitor for carbon steel in acidic medium, providing a new approach for the high value-added utilization of Salvia Milliorrhiza.

The impact of BBr3/TiCl4 ratios on the microstructural and mechanical characteristics of TiBN coatings deposited using a pulsed-PACVD technique

This study aimed to investigate the impact of precursor ratios on both the microstructural and tribological characteristics of TiBN coatings. Using the PACVD process, TiN, TiB2, and three variations of TiBN coatings with adjusted BBr3/TiCl4 ratios were applied onto H13 substrates. The coatings were characterized using XRD, FESEM, TEM, AFM, nanoindentation, and nanoscratch methods to analyze their microstructural properties, surface morphology, and mechanical behavior. The findings revealed that the TiBN coatings possessed a nanocomposite structure with TiN crystals dispersed within the BN matrix, which is amorphous. Moreover, the augmentation of the BBr3/TiCl4 ratio from 0 to 1/3 resulted in a significant rise in the hardness value, from 13.4 GPa to 25.7 GPa. However, a further increase in the ratio from 1/3 to 3/3 resulted in a decrease in hardness to 14.4 GPa because cracks were formed in the deposited coating. In comparison, the TiB2 coating exhibited a higher hardness of 19.7 GPa due to strong TiB bonds within the coating. The TiBN coating, applied with a BBr3/TiCl4 ratio of 1/3, demonstrated the lowest wear volume of 0.10 × 10−18 m3, attributed to its higher hardness and smoother surface texture.

Atomic-scale understanding of microstructural evolution in electrochemical additive manufacturing of metallic nickel

Atomic-level manufacturing is fundamentally concerned with the precise removal, addition, and migration of material at the atomic and close-to-atomic scale (ACS). Tip-based electrochemical deposition, a quintessential ACS electrochemical additive manufacturing technique, offers promising prospects for achieving bottom-up fabrication of metallic micro/nano structures. However, the complex physicochemical reactions involved in electrodes lead to a limited understanding of the mechanisms underlying atomic electrodeposition and structural evolution. For the first time, this study proposes electric double-layer controlled electrochemical kinetics and investigates the effect of direct current (DC) and pulse current (PC) on nickel atomic electrodeposition using molecular dynamics (MD) simulations. The findings reveal that compared to DC electrodeposition, PC electrodeposition results in more orderly deposition morphology, improved surface smoothness, reduced dislocation density, and lower crystal distortion, with these effects being particularly pronounced under low pulse duty ratio conditions. In addition, the pulse frequency significantly influences the morphology and structure of the deposit. The high pulse frequency yields smoother surfaces with local protrusions, while the low frequency favors the formation of orderly and dense structures excepting slightly increased roughness. This study provides critical insights into understanding the microscopic mechanisms of atomic-scale electrodeposition processes and achieving atomically controlled tip-based electrochemical additive manufacturing of micro/nanodevices.

Co-adsorbed self-assembled monolayer enables high-performance perovskite and organic solar cells

Self-assembled monolayers (SAMs) have become pivotal in achieving high-performance perovskite solar cells (PSCs) and organic solar cells (OSCs) by significantly minimizing interfacial energy losses. In this study, we propose a co-adsorb (CA) strategy employing a novel small molecule, 2-chloro-5-(trifluoromethyl)isonicotinic acid (PyCA-3F), introducing at the buried interface between 2PACz and the perovskite/organic layers. This approach effectively diminishes 2PACz’s aggregation, enhancing surface smoothness and increasing work function for the modified SAM layer, thereby providing a flattened buried interface with a favorable heterointerface for perovskite. The resultant improvements in crystallinity, minimized trap states, and augmented hole extraction and transfer capabilities have propelled power conversion efficiencies (PCEs) beyond 25% in PSCs with a p-i-n structure (certified at 24.68%). OSCs employing the CA strategy achieve remarkable PCEs of 19.51% based on PM1:PTQ10:m-BTP-PhC6 photoactive system. Notably, universal improvements have also been achieved for the other two popular OSC systems. After a 1000-hour maximal power point tracking, the encapsulated PSCs and OSCs retain approximately 90% and 80% of their initial PCEs, respectively. This work introduces a facile, rational, and effective method to enhance the performance of SAMs, realizing efficiency breakthroughs in both PSCs and OSCs with a favorable p-i-n device structure, along with improved operational stability.