Uniform Surface Research Articles

Numerical investigation on heat transfer and pressure drop characteristics of Micro-Pillar array surface

The array surface structure can improve heat transfer efficiency and achieve large heat transfer area per unit of volume. In this study, a numerical simulation using CFD method was carried out to construct a dual-channel three-dimensional mathematical model with micro-pillar array surface. The characteristic of heat transfer and flow resistance for the arrayed surface structure have been studied. In addition, four different array configurations, including cylindrical, elliptical, quadrangular and herringbone, were considered to compare the thermal performance and flow behavior. The configuration with the best overall performance was obtained as cylindrical by comparison. The effects of different heights, arrangement methods and pitches on the system performance were analyzed. The velocity distribution on the array surface was also obtained. It is found that the cylindrical array structure has obvious advantages in overall performance, with more uniform surface velocity distribution and better overall performance at lower Re conditions.

Evaluating the effects of envelope features on the pollutant distribution and ventilation performance by CFD simulations and scaled outdoor experiments

Previous studies on the effects of envelope features on ventilation performance have neglected the buoyancy effect or simplified it as a uniform surface heating effect. However, envelope features can create a shading effect that changes the temperature distribution and enhances the buoyancy effect, thus resulting in inaccurate findings. We conducted computational fluid dynamics (CFD) simulations based on scaled outdoor experiments to investigate the effects of different envelope features (balconies, overhangs, and wing walls) on pollutant dispersion and ventilation performance. The buoyancy effect created a new local vortex and changed the wind flow pattern at the base of the flat-facade and wing wall street canyons. The age of the air at the base of the flat-facade, balcony, overhang, and wing wall street canyons increased by 30.23 %, 20.45 %, 21.74 %, and 30.95 %, respectively. Moreover, when investigating the effects of envelope features on ventilation performance while ignoring the buoyancy effect, there was a high error rate in the ventilation performance, and the rates were as follows: wing wall (24.03 %) > flat-facade (23.20 %) > overhang (18.56 %) > balcony (14.05 %). This study provides a suitable methodology for investigating the effects of different envelope features on pollutant dispersion and ventilation performance in two-dimensional street canyons.

Investigating Slurry Flow Patterns in Chemical Mechanical Polishing (CMP) Using Computational Fluid Dynamic (CFD) Simulations

Chemical Mechanical Polishing has emerged as a leading area approach for planarizing wafer surfaces during semiconductor manufacturing due to its ability to provide defect-free and uniform surfaces. Achieving nanoscale planarity on a wafer and die is one of the most significant steps in the process [1]. As part of the CMP process, it is essential to understand the interactions between consumables to facilitate the production of smooth and mirror-like surfaces [2], [3]. Simulation and numerical modeling have become critical means for elucidating intricate flow patterns to probe the underlying fundamentals of CMP processes. The computational fluid dynamics (CFD) simulations provide a detailed understanding of fluid flow behavior for various conditions [4], [5]. This study uses a three-dimensional CFD simulation to provide an understanding of the slurry flow pattern and its effects on CMP performance. Several CFD simulations were performed to study the effect of different parameters on slurry flow patterns. The simulations provided information on the interaction between the slurry, the wafer surface, and the polishing pad, in addition to the abrasive distribution, slurry velocity, and pressure variations within the CMP tool. It was observed that changing the pad and wafer rotation speeds, the wafer-pad gap size and the center-to-center distance affect the slurry flow conditions. For the same rotational speeds, as the center-to-center distance decreases, the flow velocity increases toward the wafer edge. Moreover, with the same rotation speed, the pad rotation dominates the wafer rotation speed.[1] B. Suryadevara, Advances in Chemical Mechanical Planarization (CMP). Woodhead Publishing, 2021.[2] J. Seo, Journal of Materials Research, 36, 235–257, 2021.[3] A. R. Mazaheri and G. Ahmadi, J Electrochem Soc, 150, G233, 2003.[4] J. Tu, K. Inthavong, and G. Ahmadi, Springer Science & Business Media, 2012.[5] G. Ahmadi, “Chapter 2 -, R. Kohli and K. L. Mittal, Eds., Oxford: William Andrew Publishing, 2012, pp. 81–105.

Microstructure Evolution of Electrodeposited Magnesium on Copper Current Collector during Cycles for Anode-Free Rechargeable Magnesium Battery

Rechargeable magnesium (Mg) batteries attract lots of interest owing to their high theoretical volumetric energy density and low cost from the natural abundance of Mg. Additionally, Mg is less prone to dendrite growth during charging, which improves the battery safety. However, rechargeable Mg battery systems suffer from sluggish reaction kinetics on the electrodes and poor cycle life, greatly limiting their practical competitiveness. While most studies of rechargeable Mg batteries focus on the development of electrolytes and their feasibilities, the microstructure evolution of the Mg metal anodes during cycles is not fully unveiled. Furthermore, when using Mg metal as the anode, the excessive Mg may limit the overall energy density of the cells. Recently, anode-free battery systems were introduced to further improve the battery capacity. In this report, we investigated anode-free rechargeable magnesium batteries by electrodepositing Mg on a copper (Cu) current collector in an all phenyl complex (APC) electrolyte. Afterward, the microstructure evolution of the electrodeposited Mg after discharge/charge cycles was studied.The electrodeposited Mg on the Cu current collector with a current density of 2.25 mA/cm2 and a capacity of 1.5 mAh/cm2 shows a uniform distribution of Mg grains with an average grain size of 1.14 ± 0.06 μm. Subsequent Mg stripping with half the deposited capacity (0.75 mAh/cm2) was conducted at various current densities. Stripping with intermediate current density (0.75 mA/cm2) results in non-uniform discharge holes and possible local exposure of the Cu current collector, which could deteriorate the anode integrity. In contrast, the stripped electrodeposited Mg at relatively large (2.25 mA/cm2) and small (0.25 mA/cm2) discharge current densities show dense and uniform discharged holes on the surface. After prolonged discharge/charge cycles at a relatively large current density (2.25 mA/cm2), the electrodeposited Mg still exhibits a uniform surface morphology. In addition to cycling the electrodeposited Mg, a Mg-sulfur (Mg-S) full cell was also assembled with an anode of electrodeposited Mg on Cu and a sulfur/graphite cathode to explore the potential of anode-free rechargeable Mg-S battery. Figure 1

(Dielectric Science and Technology Poster Award, 2nd Place) Activation of Amine Chemistries for the Enhanced Particle Removal Efficiency of CeO2 Nanoparticles Via Megasonic Processing Conditions

With the persistent advancement of semiconductor technology, the demand for high-efficiency device manufacturing processes has surged. Chemical Mechanical Planarization (CMP) is a cornerstone for achieving angstrom-scale surface uniformity crucial for integrated circuits (IC) and logic devices. Shallow Trench Isolation (STI) CMP involves the selective removal of bulk oxide to electrically isolate active components on wafer surfaces. The modulation of the Ce3+ to Ce4+ surface state is essential for improved performance in both CMP and post-CMP (p-CMP) applications. Ce3+ is ideal for oxide material polishing due to its strong adherence to oxide surfaces, while Ce4+ is optimal for p-CMP cleaning, given its weak bond to oxide surfaces. Current p-CMP industry-standard methods utilize mechanical approaches, such as polyvinyl alcohol (PVA) brush scrubbing. However, this process induces high levels of shear force (SF), leading to secondary defects on the wafer surface (i.e. scratches, corrosion, increased surface roughness). To address these limitations, non-contact cleaning methods utilizing megasonic energy have emerged, which rely on generating reactive oxygen species (ROS) to induce particle removal. Thus, this study focuses on enhancing ceria particle removal during post-CMP cleaning by employing amine-based chemistries coupled with megasonic energy. While preliminary results imply that the mechanical cavitations induced by megasonic waves improve cleaning efficiency, this method will be optimized via the introduction of amine-based chemistries. Specifically, this work aims to leverage the unique properties of amines coupled with megasonic energy to facilitate enhanced ceria removal through electron donation, inducing a reduction in the oxidation state of ceria from Ce³⁺ to Ce⁴⁺. This approach improves particle removal while limiting secondary defects, enhancing redox activity induced by megasonic waves and chemical interactions. The mechanisms behind this method will be validated with CeO2 oxidation state kinetics, interfacial frictional changes, wafer surface roughness analysis, and SEM validation of particle removal efficiency.

Compatibilizing and foaming of PC/PMMA composites with nano‐cellular structures in the presence of transesterification catalyst

AbstractCompatibility of polycarbonate (PC) and polymethyl methacrylate (PMMA) alloys was improved by using a transesterification catalyst (SnCl2·2H2O). Modified PC/PMMA alloys exhibit single Tg, and their initial island phase existing in the SEM were transformed into uniform surface. Besides, the transmittance of the modified alloys was increased from original 40% to 85%. Moreover, PC/PMMA alloys and PC foams with micro‐cellular and nano‐cellular structures were prepared by solid‐state CO2 foaming in the presence of transesterification catalyst. Distinctively, there are obvious nano‐cellular structures existing in the PC samples, but no related nanostructures were found in PMMA samples, after treated by same amount of catalyst and foaming process for pure PC and PMMA matrix. Furthermore, the effects of foaming temperature and segment structure on their foaming behavior were also studied. Additionally, a uniaxial stress experiment was conducted at a specific temperature to simulate the biaxial stress during the foaming process for discovering the mechanism of nanopore formation. Therefore, the concept of nano‐cellular structures will point out a direction for the development of high‐performance, heat insulation PC materials of the next generation.Highlights Transesterification catalysts enhanced compatibility between PC and PMMA. Nanopore structures were successfully constructed in PC foams. Segment stretching was the main reason for the formation of nanopores.

Efficiency improvement of antimony selenide solar cells based on S-doped SnO2 buffer layer

Antimony Selenide (Sb2Se3) exhibits potential as a solar energy material owing to its optimal bandgap, lack of toxicity, and abundance of earth abundant elements. Currently, cadmium sulfide (CdS) serves as the predominant buffer layer for Sb2Se3 solar cells. However, the use of CdS hinders environmentally friendly advancement due to the toxic properties of the element cadmium. Hence, the quest for non-toxic buffer layers poses a significant challenge to the further advancement of Sb2Se3 solar cells. In prior research, tin oxide (SnO2) has been explored as a buffer layer. Nonetheless, the efficiency of SnO2/Sb2Se3 solar cells was hampered by the rough surface of SnO2 films and the poor crystallinity of Sb2Se3 films. In this investigation, we enhanced device efficiency by improving the uniformity of the SnO2 surface and enhancing the crystallinity of Sb2Se3 through spin-coating sulfur (S) onto the SnO2 film. Detailed examinations were conducted on the structure, optical, and electrical properties of the respective SnO2 and Sb2Se3 thin films. Ultimately, an efficiency of 3.38% was achieved using the spin-coated S:SnO2 film, marking an 85% enhancement compared to the baseline device.

Evolution of Surface Chemistry in Two‐Dimensional MXenes: From Mixed to Tunable Uniform Terminations

AbstractSurface chemistry of MXenes is of great interest as the terminations can define the intrinsic properties of this family of materials. The diverse and tunable terminations also distinguish MXenes from many other 2D materials. Conventional fluoride‐containing reagents etching approaches resulted in MXenes with mixed fluoro‐, oxo‐, and hydroxyl surface groups. The relatively strong chemical bonding of MXenes’ surface metal atoms with oxygen and fluorine makes post‐synthetic covalent surface modifications of such MXenes unfavorable. In this minireview, we focus on the recent advances in MXenes with uniform surface terminations. Unconventional methods, including Lewis acidic molten salt etching (LAMS) and bottom‐up direct synthesis, have been proven successful in producing halide‐terminated MXenes. These synthetic strategies have opened new possibilities for MXenes because weaker surface chemical bonds in halide‐terminated MXenes facilitate post‐synthetic covalent surface modifications. Both computational and experimental results on surface termination‐dependent properties are summarized and discussed. Finally, we offer our perspective on the opportunities and challenges in this exciting research field.

Evolution of Surface Chemistry in Two-Dimensional MXenes: From Mixed to Tunable Uniform Terminations.

Surface chemistry of MXenes is of great interest as the terminations can define the intrinsic properties of this family of materials. The diverse and tunable terminations also distinguish MXenes from many other 2D materials. Conventional fluoride-containing reagents etching approaches resulted in MXenes with mixed fluoro-, oxo-, and hydroxyl surface groups. The relatively strong chemical bonding of MXenes' surface metal atoms with oxygen and fluorine makes post-synthetic covalent surface modifications of such MXenes unfavorable. In this minireview, we focus on the recent advances in MXenes with uniform surface terminations. Unconventional methods, including Lewis acidic molten salt etching (LAMS) and bottom-up direct synthesis, have been proven successful in producing halide-terminated MXenes. These synthetic strategies have opened new possibilities for MXenes because weaker surface chemical bonds in halide-terminated MXenes facilitate post-synthetic covalent surface modifications. Both computational and experimental results on surface termination-dependent properties are summarized and discussed. Finally, we offer our perspective on the opportunities and challenges in this exciting research field.

Optimization of surface filtration to enhance wafer uniformity by removing large particle in ceria slurry

Owing to the limitations of scaling down, the development of complex structures for chip design is progressing in the semiconductor industry. As a result, the chemical mechanical polishing (CMP) process has become essential for the precise control of micro-level steps and for maintaining surface uniformity between layers during the stacking process. Structural management and improved performance of the consumables used in CMP processes are required. In particular, controlling the abrasive particles in the slurry that directly contact the wafer surface is crucial. Large particles within the slurry can occur scratches and cause non-uniformity in the polishing process, thus the particle size distribution of the slurry must be regulated. In this study, two types of filtration systems were constructed to determine the optimal conditions for CMP of ceria slurry. Depth filtration effectively removes particles through a cake layer formation mechanism but has limitations in achieving a consistent pore size within the fiber layer. Consequently, separation efficiency for particle sizes is relatively low. In contrast, surface filtration consisting of a single membrane demonstrates a consistent correlation between pore size and the size of the filtered particles, resulting in high particle removal efficiency. The pore size capable of removing large particles without active particle loss was 200 nm. After evaluating slurry productivity and filter-induced agglomeration, 0.8 L per minute (LPM) was identified as the optimal flow rate. Additionally, after filtration at 0.8 LPM, the maximum reduction in removal rates was relatively small at 272.54 Å/min due to decreased edge removal rates. However, by removing large particles to implement a monodisperse state, an improvement in uniformity of 17.11 % was achieved. Therefore, the CMP performance can be enhanced using surface filtration to control the particle size distribution (PSD).

Multi-physics field coupling interface lubrication contact analysis for gear transmission under various finishing processes

Surface integrity is crucial for the load-bearing capacity, transmission performance, and service life of gears. Finishing processes can effectively improve surface quality and are widely used in gear manufacturing processes to enhance surface integrity and improve the service performance of gears. Five precision machining tests of form grinding, vibratory finishing, barrel finishing, honing, and abrasive flow machining were conducted on spur gears. High-precision surface integrity characterization methods were used to analyze the surface integrity parameters of the finished gear surfaces, including surface roughness, surface microtopography, residual stress, texture aspect ratio, roughness peak curvature radius. The finishing processes uniformity and effectiveness of the tooth profile surface were also evaluated. By using the finished rough surfaces as inputs and considering the impact of thermal elasto hydrodynamic lubrication on the gear surface, a multi-field coupling contact analysis model encompassing solid, liquid, and thermal fields at the gear meshing interface was established. Lubrication performance parameters such as oil film pressure, oil film thickness, oil film temperature rise, and friction coefficient under various finishing surfaces were compared and analyzed. Experimental results indicate that barrel finishing can simultaneously improve various parameters, such as surface roughness, texture aspect ratio, and compressive residual stress. Finishing processes can effectively reduce surface roughness, improve lubrication performance and reduce the risk of scuffing failure. This approach provided an effective method for the comprehensive evaluation of the effects of various finishing processes. The developed program offers theoretical guidance and data support for the selection and optimization design of gear surface finishing processes.

Large-Area Perovskite Solar Module Produced by Introducing Self-Assembled L-Histidine Monolayer at TiO2 and Perovskite Interface.

Perovskite solar cells have been proven to enhance cell characteristics by introducing passivation materials that suppress defect formation. Defect states between the electron transport layer and the absorption layer reduce electron extraction and carrier transport capabilities, leading to a significant decline in device performance and stability, as well as an increased probability of non-radiative recombination. This study proposes the use of an amino acid (L-Histidine) self-assembled monolayer material between the transport layer and the perovskite absorption layer. Surface analysis revealed that the introduction of L-Histidine improved both the uniformity and roughness of the perovskite film surface. X-ray photoelectron spectroscopic analysis showed a reduction in oxygen vacancies in the lattice and an increase in Ti4+, indicating that L-Histidine successfully passivated trap states at the perovskite and TiO2 electron transport layer interface. In terms of device performance, the introduction of L-Histidine significantly improved the fill factor (FF) because the reduction in interface defects could suppress charge accumulation and reduce device hysteresis. The FF of large-area solar modules (25 cm2) with L-Histidine increased from 55% to 73%, and the power conversion efficiency (PCE) reached 16.5%. After 500 h of aging tests, the PCE still maintained 91% of its original efficiency. This study demonstrates the significant impact of L-Histidine on transport properties and showcases its potential for application in the development of large-area perovskite module processes.

Structural analysis of selective laser melted copper-tin alloy

Additively manufactured complex geometries from copper alloys with high thermal and mechanical properties have drawn the attention of researchers. The present contribution explores the additive manufacturing (AM) of copper-based alloys from powder particles intended for heat sink and heat exchange applications. Selective laser melting (SLM) parameters featuring low laser beam power (160 W), moderate scanning speed (320 mm/s), and high energy density (200 J/mm³) were employed to fabricate dense components from CuSn10 particles. The present work deal with structural analysis and precision investigation of microfabrication, particularly in Struts, Tubes, and Fins. Mechanical properties (compression and hardness) for Strut structure, differential pressure evaluations for Tube structure, and analyses of thermal and electrical conductivities for Fin structure were investigated. The results showed an improvement in strength compared to those of pure copper, facilitating ease of AM. The obtained results affirm the feasibility of AM, demonstrating the successful creation of complex and combined solid-porous structures using SLM process from Cu alloys. A comprehensive structural investigation and characterization of the Cu–Sn alloy is presented here, aiming to establish a standardized approach for analysing Cu alloys. The results indicate that small-scaled structures fabricated via CuSn10 alloy exhibits a thermal conductivity of 34.3 W·m⁻¹·K⁻¹, an electrical conductivity of 4.72×10⁶ S/m, a hardness of 119 HV-50, a uniform surface roughness of 6 µm, and can withstand a force loading of 1 kN.

Na+ doped CuO: A new paradigm electrode material for high performance supercapacitors

This study investigates the influence of sodium doping on the properties of cupric oxide (CuO) thin films synthesized via spray pyrolysis. Comprehensive characterization was conducted using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDAX), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), Raman spectroscopy, Hall effect measurements, and electrochemical studies. All films exhibited p-type conductivity, with an optical band gap variation from 1.53 to 1.73 eV. XRD analysis confirmed the dominance of monoclinic CuO, with minor phases of Cu2O and Cu4O3. EDAX and XPS verified the incorporation of Cu, O, and Na elements. FESEM revealed a densely packed morphology with uniform particle distribution and rough surfaces in the electrically optimized film. The Raman spectra of doped samples showed increased intensity and sharpness, attributed to Na + ion-induced polarizability enhancement. Hall effect measurements indicated a tenfold decrease in carrier concentration and a more than tenfold increase in mobility upon sodium doping. Films doped with 4 at.% sodium exhibited the lowest resistivity. Additionally, Na doping enhanced the electrochemical performance of CuO. These findings demonstrate that sodium doping significantly enhances the electrical, optical and electrochemical properties of CuO thin films, making them suitable for applications in optoelectronic devices and supercapacitors.

Dynamic Analysis of Deformation of a Droplet on a Uniform Jet Surface

Dynamic Analysis of Deformation of a Droplet on a Uniform Jet Surface

The corrosion resistance, biocompatibility and antibacterial properties of the silver-doped dicalcium phosphate dihydrate coating on the surface of the additively manufactured NiTi alloy

Additive manufacturing (AM) of NiTi alloys has attracted significant attention for its exceptional forming precision and suitability for processing complex medical implant structures. However, challenges such as the excessive release of Ni2+, bioinertness, and insufficient antibacterial ability have emerged as primary factors impeding the application of NiTi alloy in the medical field. To address these issues, the silver-doped dicalcium phosphate dihydrate (Ag-DCPD) coating is electrochemically deposited on the LPBF-NiTi alloy surface for the first time. The study investigates the effects of varying Ag doping content (2 %, 4 %, and 6 %) on morphology, corrosion resistance, biomineralization, and long-term stability of DCPD coating using scanning electron microscopy (SEM), electrochemical analysis, and immersion tests. Results show that the 4Ag-DCPD coating exhibits the most uniform and dense surface morphology, excellent corrosion resistance, and biomineralization. The corrosion current density (Icorr) is two orders of magnitude lower than that of the LPBF-NiTi alloy matrix (from 1.1 × 10−6 to 1.4 × 10−8), and a dense hydroxyapatite (HA) layer forms after immersion testing. In vitro cell experiments indicate that the 4Ag-DCPD coating maintains high cell viability, favorable cell morphology, and excellent biocompatibility. Additionally, the 4Ag-DCPD coating demonstrates effective antibacterial activity against Escherichia coli (79.75 %) and Staphylococcus aureus (69.33 %), which reduces the risk of implantation infection. Overall, the 4Ag-DCPD coated LPBF-NiTi alloy shows promising clinical application potential as a medical implant.

Exploring the biodegradability of candidate metallic intravascular stent materials using X-ray microfocus computed tomography: An in vitro study.

In vitro testing for evaluating degradation mode and rate of candidate biodegradable metals to be used as intravascular stents is crucial before going to in vivo animal models. In this study, we show that X-ray microfocus computed tomography (microCT) presents a key added value to visualize degradation mode and to evaluate degradation rate and material surface properties in 3D and at high resolution of large regions of interest. The in vitro degradation behavior of three candidate biodegradable stent materials was evaluated: pure iron (Fe), pure zinc (Zn), and a quinary Zn alloy (ZnAgCuMnZr). These metals were compared to a reference biostable cobaltchromium (CoCr) alloy. To compare the degradation mode and degradation rate evaluated with microCT, scanning electron microscopy (SEM) and inductively-coupled plasma (ICP) were included. We confirmed that Fe degrades very slowly but with desirable uniform surface corrosion. Zn degrades faster but exhibits localized deep pitting corrosion. The Zn alloy degrades at a similar rate as the pure Zn, but more homogeneously. However, the formation of deep internal dendrites was observed. Our study provides a detailed microCT-based comparison of essential surface and corrosion properties, with a structural characterization of the corrosion behavior, of different candidate stent materials in 3D in a non-destructive way.

Vertically Resolved Analysis of the Madden‐Julian Oscillation Highlights the Role of Convective Transport of Moist Static Energy

AbstractWe simulate the Madden‐Julian oscillation (MJO) over an aquaplanet with uniform surface temperature using the multiscale modeling framework (MMF) configuration of the Energy Exascale Earth System Model (E3SM‐MMF). The model produces MJO‐like features that have a similar spatial structure and propagation behavior to the observed MJO. To explore the processes involved in the propagation and maintenance of these MJO‐like features, we perform a vertically resolved moist static energy (MSE) analysis for the MJO (Yao et al., 2022, https://doi.org/10.1175/jas‐d‐20‐0254.1). Unlike the column‐integrated MSE analysis, our method emphasizes the local production of MSE variance and quantifies how individual physical processes amplify and propagate the MJO's characteristic vertical structure. We find that radiation, convection, and boundary layer (BL) processes all contribute to maintaining the MJO, balanced by the large‐scale MSE transport. Furthermore, large‐scale dynamics, convection, and BL processes all contribute to the propagation of the MJO, while radiation slows the propagation. Additionally, we perform mechanism‐denial experiments to examine the role of radiation and associated feedbacks in simulating the MJO. We find that the MJO can still self‐emerge and maintain its characteristic structures without radiative feedbacks. This study highlights the role of convective MSE transport in the MJO dynamics, which was overlooked in the column‐integrated MSE analysis.

Biomimetic interlayer brought unexpected enhancement in permeability and rejection of polyamide nanofiltration membrane

Construction of interlayer between porous substrate and polyamide (PA) layer has been proved to be an effective way in improving membrane separation performance by the regulation of membrane structure and chemical properties. In present study, biomimetic material—1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) lipid bilayer was selected to serve as the interlayer prepared by suction filtration due to its unique advantages such as smooth, continuous, uniform and hydrophilic surface. The results showed that DOPE interlayer effectively lowered the diffusion rate of piperazine (PIP) from membrane surface to organic phase and thus contributing to the thinner and smoother PA layer. The permeability of the interlayer-based PA membrane reached 35.9 L/m2·h·bar, which was 190 % higher than pure PA NF membranes. More important, the interlayer-based PA membrane exhibited excellent Na2SO4 rejection about 99.8 % accompanied by a good separation selectivity between univalent and bivalent ions. Besides, the interlayer-based PA membrane possessed good stability to the changes of operating pressure, concentration and pH of feed solution, and the long-term NF test. Meanwhile, it performed well in removing NTU, TOC, Mg2+ and SO42− in the treatment of surface water and showed its potential in the practical application. In all, the present work brought new interlayer material in fabricating high-performance NF membrane.

High and long-lasting antifogging performance of silane based hydrophilic polymer coating

The inevitable presence of fog causes a loss of light transmission in optical materials and leads to many unacceptable and serious consequences. A promising strategy for avoiding fog is to modulate the wettability of the material surface and further change the formed way of droplets. Although many works achieved high antifogging coatings, they are lack of the long-lasting antifogging at varied conditions. In this work, a high adhesion strength and persistent antifogging capability hydrophilic coating is obtained by utilizing silane coupling agents containing double bonds such as triethoxyvinylsilane (A151) and 3-(trimethoxysilyl)propyl methacrylate (KH570) with 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and then compositing with poly(vinyl alcohol) (PVA). The coating composed of A151 has a relatively uniform and flat surface structure, due to weaker hydrolysis ability of A151 promoted the smooth condensation speed, compared to KH570. Thanks to the hydrophilic and hydrophobic balance properties of the A151-modulated coating network, the resultant coating exhibits good antifogging performance in the range of 0 °C to 90 °C, which keeps a light transmission of about 85 %. Surprisingly, the coating shows excellent adhesion (350–700 kPa) to the substrate, which is significantly better than other conventional hydrophilic antifogging coatings, and the hydrophilic and hydrophobic modulation capability and the enhanced interfacial adhesion of A151 segments provide the basis of the coating for long-lasting antifogging, which would open up a new way of durable hydrophilic antifogging coatings.