Mass Ratio Research Articles

Maillard reaction-based conjugation of pea protein and prebiotic (polydextrose): optimization, characterization, and functional properties enhancement

There is a growing demand for plant-based protein ingredients with improved functionality for use in diverse food and nutraceutical applications. In line with this, the current study aimed to investigate the effect of plant protein-prebiotic (polydextrose) conjugation on the techno-functional properties (emulsification, solubility, fat absorption and foaming) of pea proteins through wet heating Maillard reaction. Pea protein (PeP) was conjugated with polydextrose by incubating the mixture at various process conditions (pea protein: polydextrose mass ratios, temperature, and time). Response surface methodology coupled with Box–Behnken design was used to optimize multiple responses, including conjugation efficiency (CE), emulsifying activity (EAI), and foaming capacity (FC). The pea protein conjugate (optimized value) showed improved solubility throughout a wide pH (2–10) range and higher emulsification activity than pea protein alone. The development of conjugates (PeC) was validated through ultraviolet–visible spectroscopy, FTIR, and o-Phthaldialdehyde (OPA) assay. Browning index, FT-IR spectra, thermal properties, and scanning electron microscopy (SEM) micrographs were analyzed for the conjugate (PeC) obtained at optimized values. The FTIR spectra of the conjugates showed new peaks at 3100–3480 cm−1 and 1,000–1,166 cm−1 indicating conjugation. The Maillard conjugation increased the proportion of β-turn, random coil, accompanied by a decrease in α-helix, and β-sheet. These conformational changes were associated to the improved techno-functional properties of the pea protein upon conjugation, offering potential applications in the formulation of plant-based foods and beverages.

Mapping eccentricity evolutions between numerical relativity and effective-one-body gravitational waveforms

Orbital eccentricity in compact binaries is considered to be a key tracer of their astrophysical origin, and can be inferred from gravitational-wave observations due to its imprint on the emitted signal. For a robust measurement, accurate waveform models are needed. However, ambiguities in the definition of eccentricity can obfuscate the physical meaning and result in seemingly discrepant measurements. In this work we present a suite of 28 new numerical relativity simulations of eccentric, aligned-spin binary black holes with mass ratios between 1 and 6 and initial post-Newtonian eccentricities between 0.05 and 0.3. We then develop a robust pipeline for measuring the eccentricity evolution as a function of frequency from gravitational-wave observables that is applicable even to signals that span at least ≳7 orbits. We assess the reliability of our procedure and quantify its robustness under different assumptions on the data. Using the eccentricity measured at the first apastron, we initialize effective-one-body waveforms and quantify how the precision in the eccentricity measurement, and therefore the choice of the initial conditions, impacts the agreement with the numerical data. We find that even small deviations in the initial eccentricity can lead to non-negligible differences in the phase and amplitude of the waveforms. However, we demonstrate that we can reliably map the eccentricities between the simulation data and analytic models, which is crucial for robustly building eccentric hybrid waveforms, and to improve the accuracy of eccentric waveform models in the strong-field regime. Published by the American Physical Society 2024

Tetraquarks made of sufficiently unequal-mass heavy quarks are bound in QCD

Tetraquarks, bound states composed of two quarks and two antiquarks, have been the subject of intense study but are challenging to understand from first principles. We apply variational and Green’s function Monte Carlo methods to compute tetraquark ground-state energies in potential nonrelativistic QCD using a wide range of color and spatial wave functions. We find no evidence for bound tetraquarks composed of equal-mass quarks and antiquarks. Conversely, we find clear evidence for the existence of bound tetraquarks for sufficiently unequal quark/antiquark mass ratios at all overall mass scales where our effective theory results are applicable. We predict the critical mass ratios for bound state formation and study tetraquark bound states’ spatial and color structure at leading order and next-to-leading order in potential nonrelativistic QCD. Published by the American Physical Society 2024

Optimized Tungsten Disulfide via Pyrolytic Deposition for Improved Zn‐Ion Batteries

AbstractThe selection and optimization of cathode materials are crucial for enhancing the performance of aqueous zinc‐ion batteries. In this work, different active materials were created by combining Sulfur powder and polydopamine in four different mass ratios. The novel N‐doped carbon/WS2 is obtained. Thanks to the optimization of the dopamine‐carrying tungsten ion precursor and Sulfur powder (1 : 2, 1 : 4, 1 : 6 and 1 : 8), the four samples exhibited different morphology. The N−C/WS2‐6‐based zinc ion batteries with the highest specific capacity, 120.0 mAh/g in the first discharge at 2.0 A/g, and 78.0 mAh/g after 2500 cycles, with a capacity retention of 65 %, had a relatively good overall performance, according to the results. The reaction kinetics characteristics of the N−C/WS2‐6 cathode reveal that diffusion has a significant impact on the processes in the aqueous zinc ionic material N−C/WS2‐6.

Vibration characteristics of piezoelectric pipe conveying fluid subjected to fluid-structure-electrical interaction

This paper mainly investigates the vibration characteristics of piezoelectric pipe conveying fluid subjected to fluid-structure-electrical interaction. Based on the Hamilton’s principle, the dynamic equations of the cantilever piezoelectric pipe subjected to the weight and fluid-structure-electrical interaction are established and solved by using the Galerkin method. Ultimately, complex frequency and critical flow velocity are obtained. The main discussion focused on the influence of electromechanical coupling, resistive load, and dimensionless capacitance on the critical flow velocity under different lengths of piezoelectric materials. It also examined the dynamic trajectories of the real and imaginary parts of the complex frequency under various mass ratios and resistive loads. Furthermore, it explored the impact of parameters representing voltage on the stability of the system. The results indicate various stability evolutions under different lengths of piezoelectric materials, flow velocities, and parameters representing voltage. The stability of the system pipe is influenced by factors such as the length of the piezoelectric material and resistive load.

Planet migration in windy discs

ABSTRACT Accretion of protoplanetary discs (PPDs) could be driven by magnetohydrodynamic disc winds rather than turbulent viscosity. With a dynamical prescription for angular momentum transport induced by disc winds, we perform 2D simulations of PPDs to systematically investigate the rate and direction of planet migration in a windy disc. We find that the the strength of disc winds influences the corotation region similarly to the ‘desaturation’ effect of viscosity. The magnitude and direction of torque depend sensitively on the hierarchy between the radial advection time-scale across the horseshoe due to disc wind $\tau _{\rm dw}$, the horseshoe libration time-scale $\tau _{\rm lib}$ and U-turn time-scale $\tau _{\rm U-turn}$. Initially, as wind strength increases and the advection time-scale shortens, a non-linear horseshoe drag emerges when $\tau _{\rm dw} \lesssim \tau _{\rm lib}$, which tends to drive strong outward migration. Subsequently, the drag becomes linear and planets typically still migrate inward when $\tau _{\rm dw} \lesssim \tau _{\rm U-turn} \sim \tau _{\rm lib}h$, where h is the disc aspect ratio. For a planet with mass ratio of ${\sim} 10^{-5}$, the zone of outward migration sandwiched between inner and outer inward migration zones corresponds to $\sim$10–100 au in a PPD with accretion rates between $10^{-8}$ and $10^{-7}\, \mathrm{ M}_\odot \text{yr}^{-1}$.

H2 Optimization of a New Type of Tuned Lever Inerter-like Mass Damper (TLIMD) for Attenuating Structure Vibrations

The lever or the lever-type mechanism can achieve an inertia amplification effect by appropriately calibrating its structural configuration, and it is also proven to be one of the most cost-effective solution for the inerter realization compared with other mechanical devices. Benefitting from this property, the present paper adopted a new type of tuned lever inerter-like mass damper (TLIMD) for attenuating stochastic load-induced structure dynamic responses. A set of closed-form formulae for the TLIMD optimal parameters are developed by the use of H2 norm optimization criterion, wherein the structure’s inherent damping is explicitly accounted for. It is theoretically demonstrated that the TLIMD optimal parameters are mainly dominated by three critical parameters, i.e., the damper mass ratio, the lever length ratio (known as the inertia amplification ratio) and also the host structural damping. The proposed formulae for the TLIMD optimization are validated through the seismic analysis, where two classic inerter-based dampers (i.e., the tuned mass damper inerter (TMDI) and the tuned inerter damper (TID)) optimized by the numerical technique are included in the discussion. It is found that the TLIMD has a superior advantage in reducing the structure responses and also exhibits stronger robustness for the detuning condition than the classic inerter-based dampers. Furthermore, the increase in the damper mass ratio and the lever length ratio can be beneficial for enhancing its performance.

Multi-objective optimization and exergoeconomic analysis of a novel solar desalination system with absorption cooling

This paper presents a novel design for a solar-powered desalination system utilizing a single-effect absorption refrigeration cycle with a flat-plate solar collector. The NH3-H2O working fluid pair in the refrigeration subsystem produces chilled water while the rejected heat from the condenser drives a humidification-dehumidification (HDH) subsystem for freshwater generation. This cycle has been analyzed thermodynamically and exergetically to understand its key performance parameters. Furthermore, for a detailed examination and optimization, an exergoeconomic analysis was also conducted. Design parameters for this study include the tilt angle of the solar collector, Volume fraction of nanoparticles in the CuO nanofluid, Solar collector area, Base fluid mass flow rate in the collector, Mass flow rate of the strong solution, Absorber and condenser temperatures, Mass ratio and Humidifier effectiveness. The Objective functions used to evaluate the system, performance are the Cooling effect of performance (COP), Energy performance (EP), Exergy efficiency (μExe), and the Total product cost rate of the system (Ċp,Tot). The genetic algorithm optimization is employed to find the best system performance using two sets of three objective functions. The effectiveness of multi-objective optimization using LINMAP, TOPSIS, and Shannon Entropy methods is demonstrated. LINMAP and TOPSIS consistently achieved improvements in COP (32–42 %), exergy efficiency (33–48 %), and reduced total cost (89–90 %) compared to the base point, while Shannon Entropy offered slightly lower gains. These methods consistently identify superior system configurations, achieving significant improvements in performance while minimizing the total product cost rate.

Electrospun green fluorescent-highly anisotropic conductive Janus-type nanoribbon hydrogel array film for multiple stimulus response sensors

A new strategy aimed at significantly enhancing the anisotropic conductivity of hydrogel materials, along with a simple construction technology and design concept, are proposed. Anisotropic conductive hydrogel materials have attracted much attention from researchers in the field of flexible electronics for their inherent excellent properties. However, the anisotropic conductivity of the existing conductive hydrogels is not high and the preparation methods are complex. Herein, fluorescent-highly conductive anisotropic Janus-type nanoribbon hydrogel array film (named JNHAF) is successfully prepared using a combination of parallel electrospinning and post-polymerization as an example of the study. Highly oriented [2,7-dibromo-9-fluorenone (DF)/gelatin (GE)]//[carbon black (CB)/GE] Janus-type nanoribbon is used as the building block. The composition as well as the arrangement of Janus-type nanoribbons are microscopically designed and regulated to effectively separate the conductive and insulating materials, so that the samples can achieve highly anisotropic conductivity and obvious green fluorescence. When the mass ratio of GE to CB is 1:0.1, the conductive anisotropy ratio of JNHAF can reach 1.12 × 105. The degree of anisotropic conductivity of JNHAF is significantly improved compared with existing reported anisotropic conductive hydrogels, and the preparation method is simple. JNHAF responds quickly to light, tensile strain, and temperature, making it suitable for assembling multi-stimulus responsive sensors. JNHAF has excellent flexibility, degradability, mechanical properties and a certain degree of sensitivity (gauge factor of 4.29), and is used for human joint motion detection with an obvious response signal. The design idea and construction technology of this hydrogel breaks through the technical bottleneck of the low degree of anisotropy of conductive hydrogels, which will lead and expand the scientific frontiers of anisotropic conductive hydrogel materials, and provide novel design ideas and theoretical values for new hydrogel materials.

Image-driven prediction system: Automatic extraction of aggregate gradation of pavement core samples integrating deep learning and interactive image processing framework

Aggregate gradation plays a crucial role in determining the asphalt pavement performance, necessitating assessment post-construction. Additionally, efficient gradation measurement is vital for the design and construction of reclaimed pavement. This study proposes a methodology for predicting gradation based on imagery. Initially, a scanning device is devised to capture unfolded side surface images of pavement core samples. Subsequently, an interactive software named PyImageJ is developed for image post-processing and acquiring aggregate feature information. A morphological model is then introduced to determine the mass ratios among various grading levels of coarse aggregates with nominal particle sizes greater than 2.36 mm. Finally, sequence prediction models are established to forecast the mass ratios among different grading levels of fine aggregates with nominal particle sizes smaller than 2.36 mm. Simple conversion of the mass ratios can yield the gradation. Experimental results indicate that the Long Short-Term Memory (LSTM) network offers more accurate predictions for the mass ratios of fine aggregates in stone mastic asphalt (SMA-13), with an R-squared value of 0.8985. Conversely, one-dimensional convolutional neural networks (1D CNN) are better suited for predicting the fine aggregate mass ratios in asphalt concrete (AC-20 and AC-25), with R-squared values of 0.9010 and 0.8824, respectively. Visualization results demonstrate that the predicted complete gradation closely aligns with the actual values (R-squared > 0.99), opening a new avenue for evaluating pavement quality.

Electron Acceleration at Quasi-parallel Nonrelativistic Shocks: A 1D Kinetic Survey

We present a survey of 1D kinetic particle-in-cell simulations of quasi-parallel nonrelativistic shocks to identify the environments favorable for electron acceleration. We explore an unprecedented range of shock speeds v sh ≈ 0.067–0.267c, Alfvén Mach numbers MA=5–40 , sonic Mach numbers Ms=5–160 , as well as the proton-to-electron mass ratios m i/m e = 16–1836. We find that high Alfvén Mach number shocks can channel a large fraction of their kinetic energy into nonthermal particles, self-sustaining magnetic turbulence and acceleration to larger and larger energies. The fraction of injected particles is ≲0.5% for electrons and ≈1% for protons, and the corresponding energy efficiencies are ≲2% and ≈10%, respectively. The extent of the nonthermal tail is sensitive to the Alfvén Mach number; when MA≲10 , the nonthermal electron distribution exhibits minimal growth beyond the average momentum of the downstream thermal protons, independently of the proton-to-electron mass ratio. Acceleration is slow for shocks with low sonic Mach numbers, yet nonthermal electrons still achieve momenta exceeding the downstream thermal proton momentum when the shock Alfvén Mach number is large enough. We provide simulation-based parameterizations of the transition from thermal to nonthermal distribution in the downstream (found at a momentum around pi,e/mivsh≈3mi,e/mi ), as well as the ratio of nonthermal electron to proton number density. The results are applicable to many different environments and are important for modeling shock-powered nonthermal radiation.

Innovative synthesis and practical application of graphitic carbon nitride/α-zirconium phosphate in visible light-activated Knoevenagel condensation

To advance the development of efficient photocatalysts activated by visible light for environmental applications. We employed a simple approach to synthesize g-C3N4/α-ZrP composite in different mass ratios, followed by comprehensive characterization through several techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope coupled with energy dispersive X-ray spectroscopy (SEM/EDS), and UV–Visible diffuse reflectance spectra (DRS). Furthermore, the g-C3N4/α-ZrP with mass ratio 6:1 was demonstrated high performance catalytic activity in Knoevenagel condensation (Yield 88 %–96 %) in a short reaction time (5–20 min) under visible light irradiation. The use of g-C3N4/α-ZrP has transformed the traditional synthesis of carbon–carbon double bonds, offering improved reaction rates and reduced by-products. These next-generation photocatalysts also exhibit remarkable properties that facilitate the activation of substrates under milder conditions, opening up new possibilities for green and sustainable synthesis. This advancement contributes to the development of environmentally friendly and efficient synthetic methodologies.

Effects of Variable Mass, Disk-Like Structure, and Radiation Pressure on the Dynamics of Circular Restricted Three-Body Problem

In this paper, we intend to investigate the dynamics of the Circular Restricted Three-Body Problem. Here we assumed the primaries as the source of radiation and have variable mass. The gravitational perturbation from disk-like structure are also considered in this study. There exist five equilibrium points in this system. By considering the combined effect of disk–like structure and the mass transfer, we found that the classical collinear equilibrium points depart from the x–axis. We called these equilibrium points as quasi–collinear equilibrium points. Meanwhile, this combined effect also breaks the symmetry of triangular equilibrium point positions. We noted that the quasi–equilibrium points are unstable whereas the triangular equilibrium points are stable if the mass ratio μ is smaller than critical mass μc. Besides the mass ratio, the stability of triangular equilibrium points depend on time.

No Evidence for a Dip in the Binary Black Hole Mass Spectrum

Stellar models indicate that the core compactness of a star, which is a common proxy for its explodability in a supernova, does not increase monotonically with the star’s mass. Rather, the core compactness dips sharply over a range of carbon–oxygen core masses; this range may be somewhat sensitive to the star’s metallicity and evolutionary history. Stars in this compactness dip are expected to experience supernovae leaving behind neutron stars, whereas stars on either side of this range are expected to form black holes. This results in a hypothetical mass range in which black holes should seldom form. Quantitatively, when applied to binary stripped stars, these models predict a dearth of binary black holes with component masses ≈10M ⊙–15M ⊙. The population of gravitational-wave signals indicates potential evidence for a dip in the distribution of chirp masses of merging binary black holes near ≈10M ⊙–12M ⊙. This feature could be linked to the hypothetical component mass gap described above, but this interpretation depends on what assumptions are made of the binaries’ mass ratios. Here, we directly probe the distribution of binary black hole component masses to look for evidence of a gap. We find no evidence for this feature using data from the third gravitational-wave transient catalog. If this gap does exist in nature, we find that it is unlikely to be resolvable by the end of the current (fourth) LIGO–Virgo–KAGRA observing run.

Investigation of the characteristics of the heaving lock-in region of the 10:1 π-shaped section

To gain a comprehensive understanding of the intrinsic characteristics of the lock-in region of the π-shaped section, a study was conducted to investigate the influence of the Angle of Attack (AOA), damping ratio, and mass ratio on the characteristics of the two lock-in regions using a 1:50 segment model test. The Proper Orthogonal Decomposition (POD) method was employed to analyze the characteristics of the two lock-in regions, and the flow field difference between the two lock-in regions was analyzed using Computational Fluid Dynamics (CFD). The findings indicate that both the Angle of Attack (AOA) and mass ratio have comparable effects on the lock-in region. However, it is noteworthy that the AOA appears to exert a more pronounced influence on the second lock-in region, whereas the damping ratio predominantly impacts the amplitude of the lock-in region. The analysis of the distribution and jumping degree of the surface time-averaged pressure enables us to infer the key-action zone number and action position of vortices present around the given section. In the two-lock-in region, there exist two different distribution forms for the energy ratio of POD modes. The first lock-in region is primarily affected by the Karman vortex street phenomenon, whereas the second lock-in region is mainly influenced by the long tail vortex shedding.

The effect of aspect ratio and mass ratio on the flow-induced flutter of a thin flexible sheet

This study experimentally investigates the flow-induced flutter of a thin flexible sheet, focusing on how the sheet's aspect ratio and mass ratio affect its stability and flutter characteristics in the post-critical regime. The flutter frequency of the sheet was obtained using hotwire measurements, while flutter amplitude and mode shape were acquired through high-speed imaging. The flowfield around the flapping sheet was analyzed using particle image velocimetry (PIV). Based on experimental observations, we report the onset of flutter as a subcritical bifurcation with hysteresis. The dynamic characteristics of the sheet play a significant role in its flutter instability, with the onset and cessation of flutter occurring at a frequency close to the sheet's second-mode natural frequency. The results show that both aspect ratio and mass ratio significantly affect the critical wind speed and flutter characteristics in the post-critical regime. Both flutter frequency and amplitude decrease as the aspect ratio decreases. PIV measurements in various planes reveal the highly three-dimensional nature of the flow. Results from off-axis PIV show a pair of counter-rotating spiral vortices in the wake that oscillate and change orientation with the sheet's movement. Additionally, a theoretical analysis was conducted to derive an approximate analytical relationship between the aspect ratio and critical wind speed. Experimental results aligned well with theoretical predictions for sheets with low aspect ratios (aspect ratio ≤1) but deviated for sheets with higher aspect ratios (aspect ratio >1). The relevant scaling parameters have also been explored to represent the experimental data in a non-dimensional form.

Chitosan-grafted Cyclodextrin via Click Chemistry as an Encapsulating Agent to Enhance the Antibacterial Activity of Thymol

Introduction: This paper aimed to investigate, for the first time, the possibility of increasing the antibacterial activities of thymol (TH) by developing an encapsulating agent based on chitosan-grafted cyclodextrin. For this purpose, β-cyclodextrin was monosubstituted at position 6 via propargyl bromide, and chitosan’s amine groups were converted to azide functions. After alkylation and diazotization reactions, the grafting of β-cyclodextrin onto the chitosan (CSβCD) was realized via click chemistry alkyne–azide cycloaddition. Methods: The incorporation of TH into chitosan-grafted β-cyclodextrin (TH/CS-βCD) was performed by the freeze-drying method, and the encapsulation efficiency was investigated based on various mass ratios (TH:CS-βCD). The optimized inclusion complex was then thoroughly examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Results: The antibacterial activity was assessed against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis using broth-microdilution assay. Fourier transform infrared spectroscopy analysis demonstrated the successful grafting of β-cyclodextrin onto chitosan since the optimum mass ratio between TH and CS-βCD was 1:8 (w:w), corresponding to 78 ± 3.42% of encapsulation efficiency, while SEM, XRD, TGA and DSC confirmed the establishment of TH/CS-βCD inclusion complexes. Conclusion: The in vitro investigation showed that TH/CS-βCD exhibited higher antibacterial properties compared to TH in free form.

Dynamics of a hot flexible cantilever plate under natural convection heat transfer in a square cavity

This study investigates the fluid-structure interactions of a flapping plate within a square cavity under four distinct boundary conditions, where two opposing walls are heated isothermally, and the others are adiabatic. These configurations are defined as case 1 (cooled side walls), case 2 (cooled top and bottom walls), case 3 (heated bottom and cooled top wall), and case 4 (heated top wall and cooled bottom wall). The effects of non-dimensional parameters, including Rayleigh number (Ra), Cauchy number (Ca), and mass ratio (β) on plate dynamics and convective heat transfer are analyzed. Numerical investigations are executed utilizing the SU2 open-source multi-physics computational fluid dynamics solver, with a fixed Prandtl number (Pr) set at 0.71 and dimensionless temperature difference (ϵ) established at 0.6. The results show that in cases 1 and 4, the plate exhibits no observable unsteadiness, while cases 2 and 3 reveal different oscillatory behavior within certain parameter ranges, including static mode, periodic flapping mode, quasi-periodic flapping mode, and chaotic flapping mode. In particular, the configuration in case 3 possesses higher inherent instability than case 2, causing the earlier onset of Hopf bifurcation. These findings provide valuable insights into the influence of boundary conditions on the behavior of flexible structures in fluid environments, highlighting the critical role of flow instabilities and boundary conditions in determining the dynamic response of the system.

CEERS Key Paper. IX. Identifying Galaxy Mergers in CEERS NIRCam Images Using Random Forests and Convolutional Neural Networks

Abstract A crucial yet challenging task in galaxy evolution studies is the identification of distant merging galaxies, a task that suffers from a variety of issues ranging from telescope sensitivities and limitations to the inherently chaotic morphologies of young galaxies. In this paper, we use random forests and convolutional neural networks to identify high-redshift JWST Cosmic Evolution Early Release Science Survey (CEERS) galaxy mergers. We train these algorithms on simulated 3 < z < 5 CEERS galaxies created from the IllustrisTNG subhalo morphologies and the Santa Cruz SAM light cone. We apply our models to observed CEERS galaxies at 3 < z < 5. We find that our models correctly classify ∼60%–70% of simulated merging and nonmerging galaxies; better performance on the merger class comes at the expense of misclassifying more nonmergers. We could achieve more accurate classifications, as well as test for a dependency on physical parameters such as gas fraction, mass ratio, and relative orbits, by curating larger training sets. When applied to real CEERS galaxies using visual classifications as ground truth, the random forests correctly classified 40%–60% of mergers and nonmergers at 3 < z < 4 but tended to classify most objects as nonmergers at 4 < z < 5 (misclassifying ∼70% of visually classified mergers). On the other hand, the CNNs tended to classify most objects as mergers across all redshifts (misclassifying 80%–90% of visually classified nonmergers). We investigate what features the models find most useful, as well as the characteristics of false positives and false negatives, and also calculate merger rates derived from the identifications made by the models.

Study on the water and mold resistance of ZnO/polyurethane superhydrophobic coating on circuit boards

In this work, superhydrophobic coatings were prepared on circuit boards based on the susceptibility of circuit boards to harsh environments such as humidity and mold adhesion, leading to reduced service life. Firstly, cetyltrimethoxysilane and γaminopropyltriethoxysilane were used to modify zinc oxide nanoparticles with different particle sizes. Then polyurethane and modified nanoparticles were successively sprayed on the circuit boards with a spraying process, and the superhydrophobic coatings were finally produced. The impact of the zinc oxide mass ratio with different particle sizes, silane coupling agent content, and surface modifier content on the hydrophobicity of the coatings were investigated. The results show that when the mass ratio of zinc oxide (30nm) to zinc oxide (90nm) is 1:1, the silane coupling agent content is 12‰. The surface modifier content is 12‰, the hydrophobicity of the coating is the best, and its CA can be up to 169.5°, and its SA can be up to 2.8°. It exhibits good protection of circuit boards in the tests of adhesion, acid, and alkali corrosion resistance, self-cleaning performance, and anti-mold performance. Performance, so that the coating is in the future field of electronic equipment applications.