Wet Process Research Articles

Research on adaptive damper based on cone-slide valve combination regulation principle

In the wet process of semiconductor manufacturing, the high reliability and safety of the liquid supply system are crucial. The pulsation of liquid output from bellows pumps can cause pipeline vibrations, leading to reduced system lifespan and reliability, potential component damage, and ultimately decreased process yield. To address this issue, this paper proposes an adaptive damper based on a combination of cone-slide valve regulation, specifically designed to mitigate pulsations in the liquid supply system. By establishing a mathematical model of the damper, we investigated the parameters affecting its pulsation absorption rate and response characteristics, and developed a prototype. Experimental results indicate that increasing the gas chamber volume and reducing the stiffness of the bellows significantly enhance the damper pulsation absorption rate. The effective flow area of the control valve influences the response characteristics of the system. The damper demonstrates excellent pulsation suppression performance with varied system pressure and input flow rates. The proposed design method and damper model are experimentally validated, providing a theoretical foundation and technical support for optimizing liquid supply systems in semiconductor wet processes.

Evaluation of different techniques for wet granulation and pelletization processes using milk as innovative pharmaceutical excipient for pediatric use

The present study focused on the use of milk as a novel excipient for the manufacture of pharmaceutical dosage forms specifically designed for the pediatric population. Dairy milks with different fat contents were studied to deliver paracetamol orally. The World Health Organization included milk in the list of GRAS (generally recognized as safe) substances, which together with its taste-masking ability and solubility solving properties, makes it a good candidate as an excipient in formulations containing paracetamol for pediatrics. The influence of the fat content in the milk, the fraction of paracetamol, the type of diluent and drying temperature (considered independent variables) were systematically investigated using a Design of Experiments (DoE) approach for the preparation of granules for oral administration, by wet agglomeration using different processing techniques, enabled the construction of mathematical models reflecting the correlation between the variables. Four different techniques were evaluated: wet granulation by low shear mixer, wet granulation by high shear mixer, wet granulation by fluidized bed, and extrusion and spheronization. The granules and pellets obtained were characterized for size, and size distribution of agglomerates, and complete release of the drug (dependent variables), according to the European Pharmacopoeia. The fraction of fat content in the milk promoted an increase on the dissolution rate of paracetamol. The key finding of the first two process techniques was a migration of paracetamol from powdered agglomerates towards the larger particles, probably due to friction and attrition events, which created a fraction of smaller size granules due to the fragmentation and loss of powder from the larger granules. The study has confirmed the potential of milk to be a novel and efficient excipient that can be used as a liquid binder in various agglomeration techniques to deliver drugs orally.

Microplastic characteristics in rain/snow sampled from two northern Chinese cities

Atmospheric precipitation is recognized as a significant source of environmental microplastics, especially in inland waters and remote areas. However, due to the limited availability of existing data, further information on microplastics in precipitation is essential. Therefore, this study aims to elucidate the contamination of microplastics in both snowfall and rainfall while identifying potential factors that may influence their presence during atmospheric deposition. Samples of snowfall and rainfall were collected from two representative cities in Northern China across winter and summer seasons. Subsequently, microplastics were identified and quantified automatically using laser-assisted direct infrared imaging techniques. The findings indicate that microplastic concentrations are higher in snowfall (City A: 182.30 ± 190.25 items/L; City B: 301.74 ± 325.81 items/L) compared to rainfall (City A: 58.90 ± 51.00 items/L; City B: 39.20 ± 30.31 items/L), revealing significant variations in the polymer composition of microplastics. Moreover, a greater diversity of polymers was identified in snowfall relative to rainfall, despite some commonalities among polymers; fragments measuring between 20 μm to 100 μm comprised the majority of detected microplastic particles across both types of precipitation. Crucially, the frequency of precipitation events (rainfall versus snowfall) appears to affect the concentration of atmospheric microplastics, resulting in notably higher levels within snowfalls. These findings offer valuable insights into wet deposition processes by underscoring the atmospheric origins contributing to environmental microplastic pollution.

Condensable Particulate Matter Removal and Its Mechanism by Phase Change Technology During Wet Desulfurization Process

Limestone-gypsum wet flue gas desulfurization (WFGD) played a key role in SOx removal and clean emissions. However, it would also affect the condensable particulate matter (CPM) removal and compositions. The effects of the WFGD system on the removal of CPM and the contents of soluble ions in CPM were investigated in a spray desulfurization tower at varied conditions. The results indicate that the emission concentration of CPM decreased from 7.5 mg/Nm3 to 3.7 mg/Nm3 following the introduction of cold water spray and hot alkali droplet spray systems. This resulted in a CPM reduction rate of approximately 51%, reducing the percentage of CPM in total particulate matter and solving the problem of substandard particulate matter emission concentrations in some coal-fired power plants. The concentrations of NO3−, SO42−, and Cl− among the soluble ions decreased by 41–66.6%. As the liquid−to−gas ratio of the cold water spray and hot alkali droplet spray increased, CPM came into contact with more spray, which accelerated dissolution and chemical reactions. Consequently, the CPM emission concentration decreased by 17.4–19%. The liquid−to−gas ratio has a great effect on the ion concentrations of NO3−, SO42−, Cl− and NH4+, with a decrease of 28–66%. The temperatures of the cold water spray and the hot alkali droplet spray primarily affect the ionic concentrations of SO42− and Ca2+, leading to a decrease of 32.3–51%. When the SO2 concentration increased from 0 mg/Nm3 to 1500 mg/Nm3, large amounts of SO2 reacted with the desulfurization slurry to form new CPM and its precursors, the CPM emission concentration increased by 57–68.4%. This study addresses the issue of high Concentration of CPM emissions from coal-fired power plants in a straightforward and efficient manner, which is significant for enhancing the air quality and reducing hazy weather conditions. Also, it provides a theoretical basis and technical foundation for the efficient removal of CPM from actual coal-fired flue gas.

Influence of Temperature and Pressure on the Wetting Progress in 21700 Lithium‐Ion Battery Cells: Experiment, Model, and Lattice Boltzmann Simulation

AbstractThe electrolyte filling and subsequent wetting of the active material is a time‐critical process in the manufacturing of lithium‐ion batteries. Due to the metallic cell housing, the process phenomena are insufficiently accessible, preventing the replication of the wetting processes by mathematical or simulative methods and hindering efforts to accelerate the wetting process. Therefore, this publication employs a glass cell housing for electrolyte filling of a 21700 cylindrical cell to investigate the wetting at different temperatures and process pressures. In parallel, a mathematical replication of the wetting, as well as a lattice Boltzmann pore‐scale simulation, is used to evaluate the influence of these varying process boundary conditions. The results show a strong temperature dependence on electrolyte wetting and the positive effect of pressure changes in the wetting process. These findings are particularly relevant to the process design of large‐scale cylindrical cell manufacturing.

Properties of Hydrochar Derived from Arabica Coffee Agro-Industry Residues under Wet Torrefaction Method

This study utilized coffee cherry residues, which is an abundantly available source of biomass in Indonesia. One of the methods to utilize coffee plantation residues effectively is wet torrefaction. This method is well-known as a hydrothermal method, where the biomass conversion process uses liquid as a medium and reactant in the process. The objective of this work was to develop an effective procedure for converting coffee agro-waste into marketable products using hydrothermal technology. The information related to changes in physical and thermal properties were explored in this work. To achieve the research objectives, three main steps were performed, i.e., feedstock preparation, wet torrefaction, and hydrochar characterization. Two types of feedstocks were studied in this work, coffee parchment and coffee pulp. In the wet torrefaction process, each feedstock was treated using two types of solutions, i.e., distilled water and acetic acid, at different concentrations. The reaction was carried out in an autoclave with a pressure of 2 bar (g) and an operating temperature of 130 ℃ for 2 hours. The properties of the hydrochar products were then analyzed using various methods, including bomb calorimetry, SEM, density, TGA-DTG, and hydrophobicity analyses. Overall, the results indicated that the hydrochar produced under acetic acid solution had better characteristics compared to that treated under distilled water. In terms of fixed carbon content and calorific value, the values increased up to 25.3% and 4,603 kcal/kg, respectively. Enhanced hydrophobicity was only observed in the coffee parchment hydrochar, where the average time required to adsorb water was 146.6 s, which can be categorized as strongly hydrophobic.

Extraction, Characterization, and Utilization of Moringa Oleifera Extract in Textile Wet Processes

Extraction, Characterization, and Utilization of Moringa Oleifera Extract in Textile Wet Processes

Influencing Factors on the Wet Impregnation of Additive‐Manufactured Catalyst Support Structures

AbstractThe wet impregnation of additive manufactured aluminum oxide cylinders with platinum is investigated. The influence of five parameters on the penetration depth and the platinum loading is evaluated. A smaller penetration depth is obtained by increasing pH, sodium chloride concentration in the impregnation solution, decreasing impregnation solution volume, heating rate during subsequent calcination, and no vacuum during prewetting before the impregnation. A pH range of 2 to 4, a low chloride concentration, a small liquid volume, and no vacuum drawing lead to high platinum uptake. This investigation is crucial in understanding and optimizing the wet impregnation process, providing practical guidance for future research with more complex structures.

Investigation of etch rate distribution by micro-hemisphere for the anisotropic wet etching of Ga-face gallium nitride crystal

The Ga-face gallium nitride (GaN) crystal has recently attracted significant research interest in the micro/nano device due to its exceptional properties. Therefore, exploring low-cost and high-efficiency anisotropic wet etching processes for GaN material is essential. This research investigates the measurement of the overall anisotropic etching rates by introducing a novel micrometer-level hemispherical structure. For the first time, we report the full anisotropic etching rate distribution for Ga-face GaN crystal planes based on the etched results of the micro hemisphere and wagon-wheel structure specimen. The etching experiments were carried out in 85 %wt H₃PO₄ etchant at 130°C and 150°C. The etching result of Ga-face GaN crystal orientations displays a hexagonal symmetry pattern. In addition, the overall etch rates measurement enables the identification of the crystal planes with maximum and minimum etch rates at different temperatures, and the experiment also shows the etch rate of primary crystallographic orientations, such as +c-plane, m-plane, and a-plane. Finally, the atomic structures of GaN crystallographic planes are analyzed to explain the anisotropy in the etching process on different crystal zones by the step-flow mechanism. The resulting etch rate database allows the numerical simulation of the etch front and helps understand the etching mechanism of the GaN crystal.

Preparation and properties of polytetrafluoroethylene/zinc oxide antibacterial filaments

AbstractThe potential of polytetrafluoroethylene (PTFE) products as surgical dressings is considerable, yet their absence of antibacterial properties substantially restricts their medical applications. To enhance the utility of PTFE in the medical sector, this research loaded nano zinc oxide (ZnO) particles into the PTFE filament matrix through a wet spinning process. This approach successfully yielded PTFE/ZnO composite filaments with antibacterial properties. The characterization results of the filaments show that when the mass ratio of PTFE to ZnO is 8:1, the filament has the best mechanical performance with a tensile strength of 6.78 MPa and an elongation at break of 274.46%. At the same time, composite antibacterial filaments under different process conditions show excellent antibacterial effects against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with an antibacterial rate of over 99%. The excellent mechanical properties ensure the ability to further process single filaments, which can be woven into fabrics, textiles, and various other products. Therefore, the composite antibacterial filaments with excellent comprehensive performance prepared in this study are expected to be applied in the field of medical fabrics.Highlights Provide new solution ideas for functional PTFE composite filaments preparation. The prepared PTFE/ZnO composite filament has good acid and alkali resistance as well as excellent antibacterial properties, which is expected to broaden the application field of PTFE filaments.

Aged Refuse Recycling to Treat Wastewater from Coffee Processing

Over the last two decades, the use of bioreactors filled with aged refuse extracted from closed areas of landfills has proven to be a viable alternative for the treatment of different types of wastewater. This study presents the results obtained during the evaluation of aged refuse used as filling material for a downflow bioreactor during the removal of the organic load present in wastewater generated in the wet processing of coffee. The tests were carried out over a period of 120 days, with 15 days to start up and stabilize the bioreactor and 105 days to perform treatability tests. The aged refuse, once extracted, was dried and sifted to a particle size of less than 50 mm. The bioreactor used had a cylindrical geometry (Ø = 0.20 m, and h = 3.40 m), and it was fed with hydraulic loads of 50, 100, and 150 L m−3 d−1. The analysis of the data obtained shows that the system studied achieves the removal of 98.3% of the initial organic load when fed with 150 L m−3 d−1. This showcases recycling aged refuse as a technically viable alternative to treat the wastewater generated during coffee processing. Also, the evaluated system has the advantage of needing a short period of time to achieve its stabilization, which turns out to be of great value, especially in its possible use in the treatment of residual water generated in the harvest of agricultural products where the period of harvest is very short.

Fabrication of Flexible Organic Field Effect Transistor Using Patterned Electrospray Deposition

ABSTRACTThe electrospray deposition (ESD) method is a wet process that uses the solution spray formed by an electric field between the needle of a syringe containing the solution and a conductive substrate or an insulated electrode. In this study, we fabricated thin films based on 6,13‐bis(triisopropyl‐silylethynyl) pentacene (TIPS‐pentacene) formed by a new direct patterning ESD method. This method utilizes an electric field applied between the nozzle and patterned electrodes on the substrate. It enables the formation of patterns on materials such as plastic films. Moreover, this ESD method allows for the control of patterned film width using the voltage on a counter‐patterned electrode. These results demonstrate that the patterned TIPS‐pentacene film width can be controlled by controlling voltage. We fabricated a flexible organic field‐effect transistor (OFET) using this method and measured its static electrical characteristics.

Extraction, Characterization, and Utilization of Tea Leaf Extract in Textile Wet Process

Extraction, Characterization, and Utilization of Tea Leaf Extract in Textile Wet Process

Fabrication of Surface-carbonated Boron Nitride Nanosheets and Their Application as Water-based Lubrication Additives

As a typical two-dimensional layered material, hexagonal boron nitride nanosheets (BNNSs) have high mechanical strength, good conductivity, and excellent lubrication performance, which have great potential as solid nano lubricant additives in tribology. When BNNS is used as a water-based or oil-based lubricant additive, its inherent chemical inertness and poor dispersion stability make it difficult to achieve optimal anti-friction and anti-wear performance. In this paper, a simple and efficient preparation method for obtaining hexagonal boron nitride nanosheets (C-HPC-BNNSs) with surface carbonization modification and excellent dispersion stability in water-based lubricants was proposed. Using hydroxypropyl cellulose (HPC) as a modifier, a wet ball milling process combined with high-temperature carbonization treatment effectively reduced the thickness of BNNSs while uniformly modifying N-doped carbon layers on the surface of the nanosheets. Benefit from the smaller layer thickness of C-HPC-BNNSs, they exhibit excellent dispersion stability in the water-glycol solution and can maintain no significant agglomeration behavior for up to 30 days, which is the basis for the excellent lubrication performance of lubricant systems. In addition, the N-doped carbon layer modified on the surface is beneficial for enhancing the hydrophilicity of BNNSs and synergistically enhances the tribological properties of the material with BNNSs. The test results of the four-ball friction tester show that compared with the pure water-glycol solution and the water-glycol system with added C-HPC-BNNSs, the friction coefficient (COF) and wear volume of the system with added C-HPC-BNNSs could be as low as 0.095 and 1.99 × 10-4 mm3, respectively. This work has positive significance for the preparation, surface modification, and tribological application expansion of two-dimensional layered material BNNSs, which is conducive to further understanding the relationship between.

In-situ grown NiFeLDH nanosheets over nitrogen rich amorphous carbon nanotubes: An electrochemical sensing platform for the detection of depression biomarker

In this work, intrinsic conductivity mismatch of NiFe layered double hydroxide (NFL) catalysts and agglomeration of nanosheets were addressed by introducing N doped carbon nanotubes (NCNTs) which improves catalytic activity. Using a one-step wet chemical process, CNT-supported NiFeLDH nanosheets (NFL/NCNTx, x=20, 50 and 100) were effectively created. This work delves into the lower level sensitive electrochemical detection of serotonin (5-HT) by utilising synergy of CNT and LDH. The modified NFL/NCNT exhibits better electrochemical activity, appreciable sensitivity and spanned a concentration range of 0.01 - 400 μM with detection limit stood at 1.2 nM due to the plethora of electrochemical active surface area, remarkable conductivity and appreciable stability. Impressively, 96.0 - 96.8 % and 96.7 - 97.2 % recovery rates achieved in human urine and serum samples were well close to HPLC data, signifying its feasibility for real-time monitoring. The operational stability of the proposed sensor retained up to 89.13 % for 6 weeks. The present study highlights that tailoring NFL-NCNT heterojunction is an important strategy for the development of active and stable sensing platform.

Surface Wetting Behaviors of Hydroxyl-Terminated Polybutadiene: Molecular Mechanism and Modulation.

The surface wetting or coating of materials by polymers is crucial for designing functional interfaces and various industrial applications. However, the underlying mechanisms remain elusive. In this study, the wetting behavior of hydroxyl-terminated polybutadiene (HTPB) on a quartz surface was systematically investigated using computer simulation methods. A notable tip-dominant surface adsorption mode of HTPB was identified, where the hydroxyl group at the end of the polymer chain binds to the surface to initiate the wetting process. Moreover, it was found that with the increase in the degree of polymerization (e.g., from DP = 10 to 30), spontaneous adsorption of HTPB becomes increasingly difficult, with a three-fold increase in the adsorption time. These results suggest a competition mechanism between enthalpy (e.g., adhesion between the polymer and the surface) and entropy (e.g., conformational changes in polymer chains) that underlies the wetting behavior of HTPB. Based on this mechanism, two strategies were employed: altering the degree of polymerization of HTPB and/or regulating the amount of interfacial water molecules (e.g., above or below the threshold amount of 350 on a 10 × 10 nm2 surface). These strategies effectively modulate HTPB's surface wetting process. This study provides valuable insights into the mechanisms underlying the surface adsorption behavior of HTPB and offers guidance for manipulating polymer wetting processes at interfaces.

Boron-Intercalation Engineering toward Defected 1T Phase-Rich MoBxS2-x-Supported IrOx Clusters for Acidic OER.

The construction of supported Ir-based catalysts can effectively reduce the amount of Ir and generate a synergistic effect that enhances the oxygen evolution reaction (OER) activity and stability, making it one of the effective solutions for optimizing acidic OER catalysts. However, most reported metal oxide supports suffer from poor acid resistance and low electrical conductivity, which are critical for the OER process. Herein, we synthesized a nanosheet-like defected 1T phase-rich MoBxS2-x via a molten salt calcination process, during which the 1T phase was formed, and B was intercalated into MoS2 to protect the 1T phase structure during annealing procedure. After the wet refluxing process, IrOx clusters were uniformly deposited on the surface of MoBxS2-x to form IrOx@MoBxS2-x, which exhibited an overpotential of 168 mV at a current density of 10 mA cm-2 with an Ir loading amount of 25.8 wt %. By comparing the OER performance of IrOx@MoBxS2-x, IrOx@MoS2(Calcinated), and IrOx@MoS2, it is demonstrated that calcination and B intercalation of MoS2 can significantly increase acidic OER performance. This work digs into the application of 1T-MoS2 as an OER catalyst support, providing strategies for the phase and morphology control of 1T-MoS2.

Mechanical and Durability Properties of Rubberized Sulfur Concrete Using Waste Tire Crumb Rubber.

The use of rubber crumbs provides a viable solution for alleviating the disposal problem of waste tires. In this study, rubberized sulfur concrete (RSC) was researched to investigate the optimal mixture proportion and to improve the mixing process in terms of compressive strength and durability performance. For the mixture of the RSC, sand, rubber particles, and micro-filler were adopted as aggregates and sulfur was used for the binding material. Moreover, two mixing processes were applied: the dry mixing process and the wet mixing process. Based on the test results, the increment of rubber particles in the mixture led to a decrease in the compressive strength for both the dry and wet mixing processes. To minimize the voids between the sand and rubber particles, the micro-filler was used at 5% of the total volume. The amount of sulfur varied slightly depending on the mixing process: 30% sulfur for the dry mixing process and 34% sulfur for the wet mixing process, respectively. Consequently, compared to the dry mixing process, the wet mixing process increased the bonding force between sulfur and rubber powder due to the simultaneous heating and combining. In toughness, the wet mixing process demonstrates a 40% higher energy absorption capability compared to the dry mixing process. For the durability performance of the RSC, the mixture with 20% rubber particles produced using the wet mixing process exhibited better corrosion and freeze-thaw resistance.

Design and fabrication of ultrathin silicon-based strain gauges for piezoresistive pressure sensor

Ultra-thin (20 μm) silicon strain gauges were fabricated with silicon-on-insulator (SOI) wafer by a newly-conceived wet etching process. Buffered oxide etchant (BOE, NH4F: HF = 6:1) solution with additives of octylamine and octanol was used for wet etching process in which the operating temperature was 50°C. Photoresist as a passivation layer was deposited on the upper side of SOI wafer to minimize strain gauge damage by chemical etchants. Small amount of octylamine and octanol were added to BOE solution to improve surface wettability and SiO2/Si selectivity. The fabricated strain gauges were attached to the pressure diaphragm and the performance of strain gauge was investigated by measuring with the hydraulic pressure system. The resistance changed linearly with tensile and compressive strains. Maximum values of non-linearity, hysteresis, thermal coefficient of resistance (TCR) and sensitivity were -0.341 %, 0.909 %, 4128 ppm/°C and 34.22 mV/V respectively. The fabricated strain gauges might be well applicable to the hydrogen pressure sensor which is detectable for high pressure range (0–900 bar).

Applications of cellulase enzyme in textile industry purified from Bacillus paramycoides S 5

Cellulases are enzymes which breaks down β -1-4-glycosidic bonds present in a complex polysaccharide cellulose. In this study cellulase producing bacteria were isolated from soil samples and efficient cellulase producing bacteria was identified as Bacillus paramycoides S 5 strain by using 16 S rRNA sequencing method. By using the same strain, cellulase enzyme was purified with different methods such as ammonium sulfate precipitation, dialysis, chromatography. The purified enzyme was tested for its applications in textile industry. The applications of cellulase enzymes in txtile industry includes wet processing, biostoning, biopolishing, softening and removal of stain from the clothes. In the present study of applications of purified cellulase enzyme in textile industry, after testing for wet processing and softening of fabrics giving the good biofinishing effects on selected fabric. In another application that is in removal of stain from cloth shows positive effect and found that cellulase has capability to remove stain colour from the cloth, later on cellulase applicability also tested on fabrics with respected to biopolishing which helps to remove the fabrics and microfibrils from the cloth giving a soft appearance to cloth. Finally cellulase was also tested for biostoning.