Application Of Foam Research Articles

Application of Nickel Foam in Electrochemical Systems: A Review

Application of Nickel Foam in Electrochemical Systems: A Review

Tailoring surface features and pore structure by carbon spiral fibers to construct the high-strength carbon foams for the fast and cyclic photo-thermal oil absorption

Two key limitations affecting the commercial application of carbon foams for fast clean-up of varied oils are the complex synthesis process and poor mechanical stability. In this work, an effective method is reported to fabricate the efficient oil-absorbing materials (CSF@MCF) of carbon spiral fibers (CSFs) anchored on melamine carbon foam (MCF) with superior mechanical properties and excellent photothermal conversion. The interwoven CSFs can not only provide extra rigidity but also reduce the stress concentration of the carbon skeleton, which greatly improves the mechanical properties with 6.3 times maximum compression stress and 4.5 times ultimate tensile strength than MCF. In addition, the pure carbon component can reduce the interface resistance and excite the free electrons more easily, thus realizing high-efficiency photothermal conversion in a wide range of wavelengths. Under light irradiation, the CSF@MCF can be quickly heated up to 70 °C and achieve ultra-high absorption of crude oil, up to 62 g g−1, due to its low density and large absorption volume. Meanwhile, the CSF@MCF exhibits impressive absorption stability with persistent superhydrophobicity and a high recovery efficiency of over 85%. Superadding its simple preparation process, low production cost, and excellent acid-alkali resistance, the CSF@MCF shows great commercial potential for effectively absorbing varied oils.

Impact of the Amylose/Amylopectin Ratio of Starch-Based Foams on Foaming Behavior, Mechanical Properties, and Thermal Insulation Performance

Starch-based foams have attracted great attention as alternatives to expanded polystyrene because of their sustainability, biodegradability, and low thermal conductivity. Herein, we report high-thermal insulation starch blend foams with systematically controlled compositions of amylose and amylopectin. Starch blend foams are fabricated using two different types of starch (i.e., waxy corn starch and high-amylose corn starch) in various blending ratios (0:10, 2:8, 4:6, 6:4, 8:2, and 10:0). The samples with different compositions of amylose and amylopectin show differences in crystallinity and rheological properties that are responsible for the foaming behavior. The samples with higher amylose content show a lower degree of the breakup of crystalline regions during gelatinization and higher viscosity, and well-expanded foaming behavior is inhibited in these samples. The samples with high amylose ratios provide irregular cell structures, high foam density, high flexural strength, low water absorption, and poor thermal insulation performance. Conversely, the samples with high amylopectin ratios provide relatively regular cell structures, low foam density, poor flexural strength, high water absorption, and excellent thermal insulation performance. Notably, the optimized sample, M26P74, which has 26% amylose and 74% amylopectin, shows equivalent levels of thermal insulation performance and flexural strength as conventional thermal insulating materials. This result suggests potential applications of starch-based foams as thermal insulating materials used in cold chains through an eco-friendly and sustainable approach.

Fabrication and Mechanical Properties of Tri‐Layer B4C‐Reinforced Al–Zn Functionally Graded Foam Having Higher Energy Absorption Efficiency

Metal foams are lightweight and have a higher impact energy absorption ability, making them suitable for various dynamic load applications. However, thin cell walls having higher porosity and lower compressive strength limit the foam's application. Density‐graded foams have superior compressive properties to uniform foam, making them a suitable lightweight candidate for dynamic loading applications. The tri‐layer functionally graded foam material (FGFM) is fabricated using the hot pressure‐assisted sintering and dissolution route by varying the porosity and B4C reinforcement. The density gradation enhances the load‐bearing capacity compared to uniform foam, and the maximum compressive strength achieved is 142 MPa. Also, the densification strain is 26% higher compared to uniform foam. B4C (9 vol%)‐reinforced FGFM shows the highest energy absorption efficiency of ≈67% due to their stabilized plateau region.

Daisy-shaped liquid bridges in foam-filled granular packings

HypothesisMany applications of liquid foams use them to fill the porosity of various granular media. How is the liquid distributed in such foam-filled systems, in which the geometry of the bubble assembly can be strongly constrained by pore confinement? ExperimentsWe study how the liquid is distributed in a grain packing filled with liquid foam, as a function of both liquid content and bubble-to-grain size ratio. Moreover, Surface Evolver simulations are carried out at the scale of a single bubble confined into a tetrahedral pore. FindingsWe reveal that foam-filled granular assemblies exhibit a robust pendular-like regime, which is reminiscent of the pendular regime in unsaturated media. The main difference is that here the liquid bridges are daisy-shaped, i.e. with a liquid core bounded by bubbly petals. A simple theoretical model is proposed to describe the foam liquid bridges between contacting grains. In the case of large bubbles, the model is compared with the Surface Evolver simulation. The model is also applied to the case of wall liquid bridge, which is compared with the experimental observation. Beyond their geometrical characteristics, the presence of these liquid bridges, which can represent almost 25% of the liquid contained in the porosity, makes it possible to imagine a new approach (binder foam-based) to bind granular assemblies and turn them to solid materials.

Passive thermal management system of lithium-ion batteries employing metal foam/ pcm composite for the development of electric vehicles

ABSTRACT Electric vehicles with a pack of lithium-ion batteries (LIBs) are taking a significant place in the field of transportation. Since lithium-ion battery efficiency relies on battery pack temperature, the temperature of the battery pack must be maintained within the safe limits for proper working of the system. This paper proposes a novel experimental method to dissipate and maintain the thermal energy emitted by LIBs based on a nickel foam/paraffin composite and a composite of copper foam/paraffin for thermal management of Panasonic NCR 18650B cylindrical lithium-ion battery cells. The results indicate that the surface temperature of the battery is reduced by 30.95% by comparing with ambient air convection and 24% temperature reduction by comparing with PCM by the application of nickel foam at a 2C discharge rate. By using copper foam/paraffin composite 34% and 25% temperature reduction by comparing with ambient air convection and PCM (paraffin) accordingly was achieved at a 2C discharge rate. Additionally, the result of temperature uniformity on the thermal management of the battery pack was also studied.

Chemical addition to wet webs using foam application

In papermaking, the conventional way to add chemicals to the web is to dose them into the fiber stock and form the paper afterwards. However, in many cases, adding chemicals directly to the stock is challenging. For example, strength aids tend to increase flocculation in the stock, which limits the addition amounts of those aids. The need for better performance of paper (and paperboard) products has given rise to the need for functionalization of paper. Adding such functional chemicals to the stock is usually rather inefficient. Hence, novel methods are needed to add chemicals to the paper bulk. One such method is dosing chemicals to the wet web via foam application. In this study, we built a laboratory-scale sheetfed dynamic foam application device and utilized it to study addition of starch to wet bleached chemithermomechanical pulp (BCTMP) paper handsheets. The impact of parameters such as vacuum level, the amount of added chemical, and the viscosity of the foaming liquid on the penetration of starch into the wet web was explored. Starch penetration into wet webs was measured via iodine-potassium iodide staining, followed by image analysis. According to our results, controlling the viscosity of the foaming liquid gives the best possibility to control the penetration.

Stability of high-salinity-enhanced foam: Surface behavior and thin-film drainage

Cocamidopropyl hydroxyl sulfobetaine (CHSB) is one of the most promising foaming agents for high-salinity reservoirs because the salt in place facilitates its foam stability, even with salinity as high as 2 × 105 mg/L. However, the synergistic effects between CHSB and salt have not been fully understood. This study utilized bulk foam tests and thin-film interferometry to comprehensively investigate the macroscopic and microscopic decay processes of CHSB foams with NaCl concentrations ranging from 2.3 × 104 to 2.1 × 105 mg/L. We focused on the dilatational viscoelasticity and dynamic thin-film thickness to elucidate the high-salinity-enhanced foam stability. The increase in dilatational viscoelasticity and supramolecular oscillating structural force (ΠOS) with salinity dominated the superior stability of CHSB foam. With increasing salinity, more CHSB molecules accumulated on the surface with a lower diffusion rate, leading to high dilatational moduli and surface elasticity, thus decelerating coarsening and coalescence. Meanwhile, the number density of micelles in the thin film increased with salinity, resulting in increased ΠOS. Consequently, the energy barrier for stepwise thinning intensified, and the thin-film drainage slowed. This work conduces to understand the mechanisms behind the pronounced stability of betaine foam and can promote the widespread application of foam in harsh reservoirs.

Effects of cleaning spray use on eyes, airways, and ergonomic load

BackgroundCleaning workers are exposed to chemicals and high physical workload, commonly resulting in airway problems and pain. In this study the response in the upper airways and the physical workload following airborne and ergonomic exposure of cleaning spray was investigated.MethodsA survey was answered by professional cleaning workers to investigate their use of cleaning sprays and the perceived effects on eyes, airways and musculoskeletal pain. A human chamber exposure study was then conducted with 11 professional cleaning workers and 8 non-professional cleaning workers to investigate the airborne exposure, acute effects on eyes and airways, and physical load during cleaning with sprays, foam application and microfiber cloths premoistened with water. All cleaning products used were bleach, chlorine, and ammonia free. The medical assessment included eye and airway parameters, inflammatory markers in blood and nasal lavage, as well as technical recordings of the physical workload.ResultsA high frequency of spray use (77%) was found among the 225 professional cleaning workers that answered the survey. Based on the survey, there was an eight times higher risk (p < 0.001) of self-experienced symptoms (including symptoms in the nose, eyes and throat, coughing or difficulty breathing) when they used sprays compared to when they cleaned with other methods. During the chamber study, when switching from spray to foam, the airborne particle and volatile organic compound (VOC) concentrations showed a decrease by 7 and 2.5 times, respectively. For the whole group, the peak nasal inspiratory flow decreased (-10.9 L/min, p = 0.01) during spray use compared to using only water-premoistened microfiber cloths. These effects were lower during foam use (-4.7 L/min, p = 0.19). The technical recordings showed a high physical workload regardless of cleaning with spray or with water.ConclusionSwitching from a spraying to a foaming nozzle decreases the exposure of both airborne particles and VOCs, and thereby reduces eye and airway effects, and does not increase the ergonomic load. If the use of cleaning products tested in this study, i.e. bleach, chlorine, and ammonia free, cannot be avoided, foam application is preferable to spray application to improve the occupational environment.

Performance enhancement of water and energy efficient foam dyeing and finishing through different foaming agents

ABSTRACT Foam dyeing and finishing is an ecofriendly alternative to conventional padding in textile processing. However, the generation and application of foam is a challenging task especially for wide range of dyes and chemicals due to technical and compatibility issues. In the foam dyeing and finishing process, foaming agent plays a central role. However, there is a lack of research on the compatibility of range of foaming agents with the range of different dyes and finishes. Therefore, in this research, foam was generated and optimized for seven different colorants including three reactive dyes, two direct dyes, and two pigments, and three different finishes including softener, oil and water repellent, and fire retardant using three different foaming agents separately. These foaming agents are alkyl dimethyl amine oxide, alkane sulfonate sodium salt, and ethoxylated decanol. Foam was successfully generated, optimized, and applied on the cotton fabric. Performance of the fabric samples treated with padding and three foaming agents for each dye and finish was evaluated. In most of the foam dyeing and foam finishing recipes, alkane sulfonate sodium salt-based foaming agent indicated the best dyeing and finishing properties and its performance was comparable with conventional padding in addition to significant savings of water, chemicals, and energy.

How Loading of Co3O4-Cs on an Open-Cell Foam Influences N2O Decomposition

Co3O4 modified with Cs was deposited on an α-Al2O3 open-cell foam, characterized by X-ray diffraction (XRD), N2 physisorption, temperature-programmed reduction by hydrogen (TPR-H2), and scanning electron microscopy-energy-dispersive X-ray analysis (SEM-EDAX) and tested for the low-temperature decomposition of N2O. The aim was to study the effect of the amount of active phase on N2O conversion. Three different approaches were used: (i) the application of foam supports with different cell sizes, (ii) influencing catalyst loading using impregnation solutions with different precursor concentrations, and (iii) deposition of the active phase precursor by repeated immersion–calcination cycles. Increasing the geometric surface area of the support, and thus catalyst loading, was successfully done using the support with higher pore densities. A higher loading was also achieved by increasing the nitrate precursor concentration in the impregnation solution. In both cases, the catalyst activity increased with an increase in the amount of the active phase. Compared to that, a repeated impregnation procedure can ensure the deposition of a higher amount of active phase in comparison to that obtained with one-step impregnation, but only the last layer is used in the reaction and the rest of the active phase remains unutilized, which makes this type of preparation unfavorable. The high catalytic activity was preserved at 450 °C even in the presence of O2, H2O, and NO.

Al-Foam Compression Tests in Parallel and Serial Concepts

Taking into consideration the additional weight of a vehicle, today’s requirements can only be met using new materials and designs. The application of metal foam is one of the most promising methods of enhancing the impact energy absorption ability of the crumple zone. The energy-absorbing capacity of thin-walled structures filled with metal foams during compression can be notably improved, which results in lower loading on the passengers. The main goal of our research is to develop a new design that is suited to absorb more impact energy while taking into consideration weight optimization. The authors wanted to unveil the effect of the inhomogeneous filler material in these thin-walled structures. Therefore, the present study investigates the compression test of two metal foams of different densities, in different ways. In the first section, the foams were compressed independently from each other by a recording of a stress–strain diagram. After the single compression, the foams were loaded together, first in parallel, and subsequently in a serial scheme. The study aimed to reveal the effect of the parallel and serial compression scheme focusing on the sum of impact energy absorption.

PFASs in Soil: How They Threaten Human Health through Multiple Pathways and Whether They Are Receiving Adequate Concern.

Per- and polyfluoroalkyl substances (PFASs) have been mass-produced and widely applied in consumer and industrial products, resulting in their widespread presence in the environment. Features such as environmental persistence, bioaccumulation, and high toxicity even at low doses have made PFASs an increasing concern. This brief review focuses on soil PFASs, especially the effect of soil PFASs on other environmental media and their potential threats to human health through daily diet. Specifically, soil PFASs contamination caused by different pathways was first investigated. Soil pollution from application of aqueous film-forming foams (AFFFs) is generally more severe than that from fluorochemical manufacturing plants, followed by biosolid land use, landfill, and irrigation. Factors, such as carbon chain length of PFASs, wastewater treatment technology, geographical conditions, and regional development level, are related to soil PFASs' pollution. Then, the migration, bioaccumulation, and toxicity characteristics of soil PFASs were analyzed. Short-chain PFASs have higher solubility, mobility, and bioavailability, while long-chain PFASs have higher bioaccumulation potential and are more toxic to organisms. Factors such as soil texture, solution chemistry conditions, enzymes, and fertilization conditions also influence the environmental behavior of PFASs. The risk of human exposure to PFASs through agricultural and animal products is difficult to control and varies depending on living region, age, eating habits, lifestyle, ethnicity, etc. Soil PFASs threaten drinking water safety, affect soil function, and enter food webs, threatening human health. Knowledge gaps and perspectives in these research fields are also included in current work to assist future research to effectively investigate and understand the environmental risks of soil PFASs, thereby reducing human exposure.

Assessment of foam generation and stabilization in the presence of crude oil using a microfluidics system

The use of foams is a promising technique to overcome gas mobility challenges in petroleum reservoirs. Foam reduces the gas mobility by increasing the gas apparent viscosity and reducing its relative permeability. A major challenge facing foam application in reservoirs is its long-term stability. Foam effectiveness and stability depends on several factors and will typically diminish over time due to degradation as well as the foam-rock-oil interactions. In this study, the effect of crude oil on CO2-foam stability and mobility will be investigated using in-house build microfluidics system developed for rapid prescreening of chemical formulations. Two-phase flow emulsification test (oil-surfactant solutions) and dynamic foam tests (in the absence and presence of crude oil) were conducted to perform a comparative assessment for different surfactant solutions. A microfluidics device was used to evaluate the foam strength in the presence and absence of crude oil. The assessment was conducted using five surfactant formulations and different oil fractions. The role of foam quality (volume of gas/total volume) on foam stability was also addressed in this study. The mobility reduction factor (MRF) for CO2-foam was measured in the absence and presence of crude oil using high salinity water and at elevated temperatures. The results indicated that foam stability has an inverse relationship with the amount of crude oil. Crude oil has a detrimental effect on foams, and foam stability decreased as the amount of crude oil was increased. Depending on the surfactant type, the existence of crude oil in porous media, even at very low concentrations of 5% can significantly impact the foam stability and strength. The oil can act as an antifoaming agent. It enters the thin aqueous film and destabilizes it. This resulted in a lower foam viscosity and less stable foams. Thus, the CO2 MRF dropped significantly in the presence of higher oil fractions. This study also demonstrated that in-house assembled microfluidics system allows for a rapid and cost-efficient screening of formulations.

Corrosion inhibitor and chelating agent impact on foam stability for formation stimulation applications

Injection of foam into petroleum reservoirs has attracted special interest in the last years. Utilizing foam in well stimulation is promising as it consumes less water than water-based fracturing fluids. Nevertheless, the success of foam application mainly depends on its stability. Thus, it is essential to understand the role of gas type, water chemistry, and other additives such as acids (e.g., chelating agent) and corrosion inhibitors on the generation and stabilization of foam. Hence, a dynamic foam analyzer (DFA) and optical interfacial tensiometer were used to study foam stability under different conditions. Surfactant screening showed that Duomeen TTM and Armovis are superior foamers at low pH (3.5), and therefore were used in this study. The liquid phase typically contained high salinity water, 15 %wt. Chelating agent, L-glutamic acid-N, N-diacetic acid (GLDA), and 1 %wt. surfactant with and without a corrosion inhibitor (CI). First, we investigated the effect of gas types on the stability of the foam. The results revealed that N2-foam is more stable compared to CO2-foam. Also, the results showed that the corrosion inhibitor reduced the foam stability for both N2-foam and CO2-foam. Three types of water were examined; distilled water (DI), produced water (PW), and seawater (SW) for foam stabilization. The water chemistry had little effect on the stability of TTM compared to its impact on Armovis. Finally, we found that GLDA addition to Armovis increased the stability of foam by four times compared to no GLDA addition. Moreover, the stability GLDA/Armovis system was six times higher with CO2 and more than 20 times higher with N2 as compared to TTM stability. The foamability, foam volume, bubble count, and foam structure were studied to determine the foam behavior at given conditions. This study provides a broad understanding of additives’ impact on stimulating foam stability.

Water-based medium-expansion foam depopulation of adult cattle

Abstract Current options for depopulation of adult cattle are limited, have logistic constraints, and may not be practical on a large scale. Aspirated water-based foam (WBF) has been shown to be successful in depopulating poultry and swine but has yet to be tested in cattle. WBF is advantageous because necessary equipment can be readily available, easy to use, and presents minimal personnel risk. With the use of a modified rendering trailer in a field setting, we evaluated the efficacy of aspirated WBF for depopulation of adult cattle. Water-based medium-expansion foam was added to the trailer holding cattle to a depth of approximately 50 cm greater than head height. The study was conducted as a gated design and the initial trial was conducted using six anesthetized and six conscious animals for verification of the process and followed by four replicates each containing 18 conscious cattle. A total of 84 cattle were used, with a subset (n = 52) implanted with subcutaneous bio-loggers that recorded activity and electrocardiograms. Cattle were loaded onto the trailer and three gasoline-powered water pumps delivered foam into the trailer followed by a 15-min foam dwell period. Average (± SD) time to completely fill the trailer with foam was 84.8 ± 11.0 s. No animal vocalizations were heard during foam application or the dwell period, and all cattle were confirmed dead upon removal from the trailer after 15 min of immersion. Necropsies of a subset of cattle revealed foam extending to at least the tracheal bifurcation in all cattle and distal to this level in 67% (8/12) animals. Time to cessation of movement, which served as a proxy for loss of consciousness, was 2.5 ± 1.3 min and time to cardiac death was 8.5 ± 2.5 min as determined by data from animals carrying subcutaneous bio-loggers. The results of this study indicate that WBF is a rapid and effective method for depopulation of adult cattle with potential advantages in speed and carcass handling and disposal over current methods.

Review of phase change heat transfer enhancement by metal foam

• Enhancement characteristics of metal foam on solid-liquid phase change heat transfer and liquid-gas phase change heat transfer are reviewed. • The mechanism of metal foam enhancing phase change heat transfer and the factors affecting the phase change heat transfer process are comprehensively discussed. • Existing methods for optimizing phase change heat transfer performance within metal foam are classified and evaluated. • The practical applications of metal foam enhanced phase change heat transfer in recent years are summarized and compared. • This review will lead to a better understanding on the designing and applying of efficient metal foam-phase change heat transfer systems. Metal foam is a novel multifunctional material with high porosity, high surface density, and excellent heat transfer performance. Embedding metal foams into phase change heat transfer systems can be used to improve the comprehensive heat transfer performance, which is receiving increasing attention in the field of thermal management. This paper focuses on the lasted advances in solid-liquid phase change heat transfer and liquid-gas phase change heat transfer within metal foams, and specifically analyzes the influencing factors on phase change heat transfer performance as well as the mechanism of metal foam effects on phase change heat transfer. Different optimized techniques for improving phase change heat transfer within metal foams and the current state of metal foam engineering applications for improving phase change heat transfer are reviewed and discussed. It is concluded that the addition of metal foam can significantly enhance the heat transfer performance of solid-liquid phase change systems and liquid-gas phase change systems, but it is accompanied by an inhibitory effect on natural convection, an obstructive effect on bubble overflow and an elevated effect on pressure drop. The application of gradient porous structure, metal foam fins, V-groove structure or changing the surface wettability of metal foam is a feasible way to alleviate the above problems. Meanwhile, it is pointed out that the heat transfer performance of phase change within metal foam is influenced by the interaction of various factors, and some key issues regarding the influence mechanism of PCM-device orientation, pore distribution, surface wettability, and structural properties on heat transfer performance still need to be studied to develop more efficient and compact heat sinks.

An effective purification of double-effect distillation for bio-based pentamethylene diisocyanate.

Bio-based pentamethylene diisocyanate (PDI) is a new type of sustainable isocyanate, which has important applications in coatings, foams, and adhesives. Technical-economic analysis of the PDI distillation process can promote the industrialization of PDI. The thermal analysis of PDI facilitates the smooth running of the simulation process. A new PDI heat capacity prediction method was established. The distillation processes of a crude PDI solution by conventional distillation and double-effect distillation were studied. Countercurrent double-effect distillation showed the best energy-saving effects in all double-effect distillation. However, combined with total annual charge (TAC), parallel double-effect distillation was the optimal method for PDI purification. Parallel double-effect distillation can significantly reduce the TAC of production PDI, which is 33.39% lower than that of the conventional distillation. The study demonstrates a clear economic incentive for reducing the cost of PDI purification by parallel double-effect distillation.

Retracted: Application of Self-Adhesive Soft Silicone Common Foam Dressing in Reducing Intraoperative Pressure Ulcers in Elderly ICU Patients.

[This retracts the article DOI: 10.1155/2021/4482201.].

Impact of fire suppressant on seed germination and seedling emergence of native and introduced flora from a Western Australian eucalypt woodland

Background Phos-Chek WD881A is a short-term retardant used by fire-fighters in Western Australia to suppress and control the movement of fire across the landscape. It is currently applied at a working concentration of 0.1–1%. Aim Our objective was to assess and quantify the impact of the suppressant on seed germination and seedling emergence across eight native and two weed species commonly found in Eucalyptus wandoo woodland. Methods Seeds were exposed to five Phos-Chek concentrations, from 0 to 10% (v/v), in a germination trial in Petri dishes, and three concentrations of 0, 0.1 and 1% (v/v) in a seedling emergence trial. Key findings Increasing concentrations of Phos-Chek both delayed and reduced germination and emergence for all species except Acacia saligna. The sensitivity to Phos-Chek varied among the tested species. Conclusions Phos-Chek had a significant impact on the germination and emergence of native and invasive species, with irreversible damage to seed viability in one taxa (Allocasuarina humilis). Implications It is recommended that applications of Phos-Chek foam remain closer to the minimum recommended concentration (0.1% v/v) to reduce adverse effects on the recruitment of sensitive species, particularly during dry autumns when leaching of this chemical is likely to be limited.