Foaming Agent Content Research Articles

Impact of Foam-Mat Drying on Plant-Based Foods Bioactive Compounds: a Review.

Plant-based foods are recognized by their remarkable content of bioactive compounds. In an attempt to increase plant-based foods shelf-life, technologies like drying can be used. Foam-mat drying is a mild drying technology that removes water, usually by using hot air, from a foam obtained by the whipping of a liquid or semi-liquid food added with a foaming agent. There are several reports on the use of foam-mat drying for extending plant-based foods shelf-life, including reports on the effect of drying on their bioactive compounds. Therefore, this study aimed at reviewing the literature on the impact of foam-mat drying on plant-based foods bioactive compounds published in the last 10 years. Results show that short foam-mat drying time is beneficial to bioactive compounds retention. In addition, hot air temperature between 40-65°C, foam thickness between 0.2 and 1cm and the use of egg white as one of the foaming agents leads to high bioactive retention. Egg white is also the most used foaming agent. Regarding the mathematical models used for fitting the foam-mat drying kinetics, the Page model was shown as the most proper model. Foaming agent concentration is a delicate parameter, as its increase in foam formulation may beneficially enhance drying rates but, at the same time, it dilutes bioactive compounds and may cause their loss by oxidation. In conclusion, foam-mat drying stands out as a suitable technology for producing food powders with high bioactive retention.

Influence of Aluminum Powder Content on Expansion Rate of Foamed Concrete

Foamed concrete is a heat preservation and noise reduction material made of cement and aluminum powder as foaming agent. The experiment mainly studies the influence of different water-cement ratio, foaming agent dosage and cement dosage on the expansion rate of foamed concrete test block. The experimental results show that when the water-cement ratio increases from 0.4 to 0.6, the expansion rate decreases gradually. When the content of aluminum powder foaming agent increased from 0.05% to 0.40%, the expansion rate showed a trend of “increasing first and then decreasing”. When other conditions are the same, the expansion rate of cement increases from 500kg/m3 to 800kg/m3, showing a trend of “decreasing first and then increasing”.

Effect of CaCO3 content change on the production of closed-cell aluminum foam by selective laser melting

CaCO3 is used as a foaming agent, and a closed-cell aluminum foam is produced by selective laser melting (SLM) technology. The relationship between foaming agent content and sample porosity, pore size, and mechanical properties was explored. It was found that as the content of foaming agent increased, the porosity also increased, the number of pores increased, the average pore diameter increased, and the merging phenomenon between pores became more. In addition, the change in the content of the foaming agent did not cause a particularly large change in the microhardness value of the metal matrix part of the foamed aluminum alloy, and the microhardness value was concentrated between 100 and 110 HV. The results of the compression experiment show that the foamed aluminum alloy manufactured by SLM has a certain degree of energy absorption characteristics and the fracture mode at room temperature is mainly brittle fracture.

Application of orthogonal experiment method in foam flooding system composition and injection parameter optimization

Excellent composition and injection parameters of foam system are essential for foam flooding to exert mobility control. This study aims to optimize foam composition and injection parameters to maximize foam mobility control. The concentrations of foaming agent and stabilizer, oil saturation, foam quality, and flow rate served as influencing factors in the orthogonal experiment method with resistance factor (RF) as the evaluation index. Results showed that cores with different permeability levels corresponded to a set of optimal injection parameters. The optimal combination scheme significantly improved mobility control relative to all test groups in the orthogonal experiment, proving the effectiveness of this method in optimizing foam flooding parameters. During the analysis of orthogonal experimental data, in addition to the method of intuitive analysis was adopted to study the influence of a single factor on the RF, the influence of multiple factors interaction on the RF was also explored. Confirmatory tests were performed on the optimal parameters of foam flooding obtained by orthogonal experiments, and the foam propagation at different positions of the core was determined. The degree of pressure fluctuation during foam flooding was measured with the standard deviation ( SD ), which was used to directly measure the strength of the Jamin effect during foam flooding. The RF distribution factor ( D RF ) was introduced to describe the uniformity of foam seepage resistance along the core axis. D RF was used to study the entrance effect on foam to establish seepage resistance. The propagation performance of foam in porous medium is crucial to maximize its mobility control. Foam injectivity in porous medium should be given attention when optimizing the injection parameters of foam flooding. • Optimal injection parameters of foam are studied by orthogonal experiment method. • Obtained the influence trend of five factors on RF under various permeability levels. • Obtained multi-factors interaction effect on RF under various permeability levels. • Introduce SD and D RF to study the propagation characteristics of foam in cores.

Experimental and numerical analysis of bubble nucleation in foaming polymer

This paper investigates the bubble nucleation of polymer (LDPE) foams using nucleation theory and establishes a mathematical model based on in-situ observations and measurements. The effects of different foaming agent contents and shot sizes on bubble nucleation were studied in an injection foaming experiment and a new mathematical model describing the bubble nucleation kinetics was obtained based on classical nucleation theory. The model fittings were obtained for different experimental conditions. The process of foaming nucleation could be characterized intuitively through this model and can be used as a general form for other nucleation processes.

Factors influencing thermal conductivity and compressive strength of natural fiber-reinforced geopolymer foams

New sustainable, environmentally friendly materials for thermal insulation of buildings are necessary to reduce their carbon footprints. In this study, Miscanthus fiber-reinforced geopolymer composites, foamed with sodium dodecyl sulfate (SDS), were developed using fly ash as a geopolymer precursor. The effects of fiber content, fiber size, curing temperature, foaming agent content, fumed silica specific surface area and fumed silica content on thermal conductivity and compressive strength were evaluated using a Plackett-Burman design of experiment. Furthermore, the microstructure of geopolymer composites was investigated using X-ray diffraction (XRD), X-ray micro-computed tomography (μCT) and scanning electron microscopy (SEM). The measured characteristic values were in the following ranges: Thermal conductivity 0.057 ​W ​(m ​K)−1 to 0.127 ​W ​(m ​K)−1, compressive strength 0.007 ​MPa–0.719 ​MPa and porosity 49 ​vol% to 76 ​vol%. The results reveal an enhancement of thermal conductivity by elevated fiber size and foaming agent content. In contrast, the compressive strength is enhanced by high fiber content. Additionally, SEM images indicate a good interaction between the fibers and the geopolymer matrix, because nearly the whole fiber surface is covered by the geopolymer.

Effect of foaming agent concentration and drying temperature on biochemical properties of foam mat dried tomato powder

The purpose of the study was to optimize the effective drying conditions and different foaming agent concentrations on the biochemical properties of foam mat dried tomato powder. Foaming was achieved by using egg albumin as foaming agent and sodium salt of Carboxymethyl Cellulose (CMC) as foam stabilizer with different concentrations. Drying was achieved by using different drying temperatures. The changes in different physicochemical properties of foam mat dried powder viz. total soluble solid (TSS), pH, ascorbic acid, titratable acidity, β-Carotene, DPPH radical scavenging activity were observed. Foams were prepared from different concentrations of egg albumin (3-7% w/w) and sodium salt of Carboxymethyl Cellulose (1%, 0.5%). The drying temperatures were varied from 60°C to 70°C. The drying time changes with different drying temperatures. It was found that the drying time decreased with the increased foaming agent concentrations as well as with higher drying temperature. It takes almost 13 hrs for drying at 70°C. TSS and pH content was increased with the increase of foaming agent concentrations and foam stabilizer’s concentrations but decreased with the increasing temperatures. Ascorbic acid decreased with the increase of foaming agent concentrations and temperatures but increased with CMC concentration. Titratable acidity content of foam mat dried tomato powder was decreased with the increasing foaming agent concentrations but increased with the higher temperatures and decreased CMC concentration. β-Carotene contents increased with the increase of foaming agent concentrations but decreased with the increase of temperatures and foam stabilizer concentration. DPPH free radical scavenging activity increased with the increase of foaming agent, foam stabilizer and temperatures. Based on the maximum retention of physicochemical properties, the optimum treatment of foaming agent was found to be 7% egg white + 1% CMC at 60°C.

Innovation and characterization of a new multifunctional light weight low cost construction material from foamed rubber blend

New amendment in vulcanization process was used to prepare foamed rubber with enhanced physical properties other than expected and desirable thermal insulation properties. In this work the influence of foaming agent loaded NR/ SBR on thermal conductivity, density, water absorption swelling and mechanical properties was investigated. Different concentrations of foaming agent (2, 4, 6, 8, and 10 phr) were added to rubber matrix. The morphology of selected samples was characterized using scan electron microscope (SEM). An experimental investigation was carried out to obtain low cost multifunctional construction material with desirable mechanical and thermal insulation properties. The addition of foaming agent led to a decrease in thermal conductivity and density values until the concentration of 8phr after that their values slightly changed. It was also observed that mechanical properties of blends were improved with the addition of foaming agent. The optimum concentration was found to be 8phr for all measurements

Research on the Influencing Factors of the Strength of Lightweight High Strength Foamed Cement

In order to explore the factors affecting the strength of lightweight and high-strength foamed cement, ordinary Portland cement is used as the cementing material, and the target dry density is 400~410kg/m3 by controlling the content of foaming agent and foam stabilizer. Lightweight high-strength foamed cement specimen with strength of 4.4MPa. Controlling a single variable, the compressive strength and microscopic morphology changes of foamed cement specimens with different self-made reinforcing agent content and fly ash content were studied. The research results show that when the fly ash content is 20%, the strength of the sample without reinforcing agent reaches the best 2.4MPa; when 2wt% of the reinforcing agent is added, the strength of the sample reaches the maximum compressive strength of 4.4MPa, an increase of 83 %. Scanning electron microscope microscopic morphological observation results show that after adding the reinforcing agent, the foamed cement cell is more uniform, the cell wall becomes denser, and the cell defects are reduced, which explains the macroscopic advantages of lightweight and high-strength foamed cement.

Impact of foaming agent and nanoparticle fillers on the properties of irradiated rubber

Abstract A sponge rubber nanocomposite based on styrene–butadiene rubber (SBR)/nanoclay (montmorillonite, MMT) or nano-calcium carbonate (CaCO3) fillers with various foaming agent contents was produced by a simple technique, roll milling. The nanoparticles were examined by different techniques, such as X-ray fluorescence (XRF), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), and Fourier-transform infrared (FT–IR). The sponge rubber nanocomposites were characterized by scanning electron microscopy (SEM) image analysis before and after exposures to radiation doses, as well as by the XRD patterns for the unirradiated samples. The different properties of the obtained nanocomposites, including their foaming degree, tensile strength, elongation at break, and thermal conductivity, were also investigated. The foam composites containing nano-CaCO3 possessed the best cell and crosslinking densities and mechanical properties among the other composites, while its foaming degree was the lowest. The results indicated that the thermal conductivity was reduced by increasing the foaming agent concentration. However, it increased as the radiation dose increased, and the optimum radiation dose was obtained at 75 kGy. The foam containing MMT exhibited an intermediate behavior while high thermal conductivity was recorded for the foam containing the CaCO3 nanoparticles.

Banana Powder Production via Foam Mat Drying

Banana puree is one of the main commercial banana products available in the market worldwide. However, like other purees, banana puree deteriorates quite rapidly and gets a chilling injury when refrigerated. Therefore, this study focused on the dehydration of banana puree using a foam mat drying (FMD) technique to prolong its shelf life. It involved whipping the banana puree to form foams with the help of whey protein concentrate (WPC) and carboxymethyl cellulose (CMC) as the foaming agent and foam stabilizer, respectively. The study evaluated the effect of different foaming agent percentages (5, 7.5, 10, 12.5 and 15%) and drying temperatures (50, 60, 70 and 80°C) on the production of the foam mat dried banana powder. Besides that, the drying curves of banana puree using FMD and oven drying methods were compared. The banana powders produced were also analyzed in terms of the foam density, moisture content, solubility, color (browning index) and flowability (caking strength). Based on the findings, the FMD technique has proven to produce a good quality banana powder better than the control sample especially at a higher foaming agent concentration (15%) and drying temperature (80°C). By using the FMD technique, the banana puree has the capacity to be dried three times faster compared to the conventional oven drying method to form a more stable banana powder.

Preparation of autoclaved aerated concrete by using graphite tailings as an alternative silica source

This research aims to produce autoclaved aerated concrete (AAC) by using graphite tailings as siliceous material. The influences of cement dosage, calcium-silicon mole ratio (Ca/Si), water-solid materials ratio (W/S), and foaming agent content on the compressive strength and bulk density of graphite tailings-autoclaved aerated concrete (GT-AAC) were examined. Moreover, the hydration and microstructure of selected GT-AAC compositions were investigated by employing X-ray diffraction analysis, Fourier transform infrared spectroscopy, thermogravimetry, scanning electron microscopy, and 29Si nuclear magnetic resonance. The results manifested that, except for the cement dosage, water-solid materials ratio, and foaming agent content, the calcium-silicon ratio also plays an important role in the production of GT-AAC. GT-AAC with compressive strength of 5.0 MPa and bulk density 666 kg/m3 was successfully produced by adopting the appropriate mix proportion obtained herein. Microscopic investigation verified the main hydration products of GT-AAC were tobermorite and C-S-H gel.

A simple optimized foam generator and a study on peculiar aspects concerning foams and foamed concrete

This paper presents a study on peculiar aspects influencing foams and foamed concrete properties, starting from the foam generation up to the compressive strength of the lightweight and ultra-lightweight cementitious material. In particular, after a brief introduction on foam stability, this research work shows a simple and inexpensive foam generator used to produce the commonly used foams in concrete. The significant influence of the air pressure value, of nature and concentration of the foaming agents on density as well as the percentage drainages of the foams produced are therefore discussed. The results show that foams generated with the protein foaming agent have more suitable characteristics to produce foamed concrete, thanks to the significantly longer lifetime compared to foams produced with the synthetic foaming agent. The latter are characterized by very high drainage values even after a few minutes from their generation. Foams are then used to make lightweight (target dry density equal to 600 kg/m3 and 800 kg/m3) and ultra-lightweight (target dry density of 400 kg/m3) foamed concretes that show interesting results in terms of stability also when foams with high drainages are employed. The study provides explications of the differences between the compressive strength of lightweight foamed concrete obtained with foams generated using protein and synthetic foaming agents. Then, the significant influence of the increase in concentration of protein foaming agent on the compressive strength of ultra-lightweight foamed concretes is presented.

Waste Glass Reuse in Foamed Alkali-Activated Binders Production: Technical and Environmental Assessment

Waste glass is a type of construction and demolition waste (CDW), which carries significant environmental burdens and can be recycled. In this study, a foamed alkali-activated glass (FAAG) via the use of milled waste glass was synthesized in low-temperature (i.e., 80 ⁰C). The influence of foaming agent (i.e., aluminum powder) content on the foaming process of samples was investigated and optimized in view of their performance. The optimum mix formulation, which is FAAG with 10% aluminum powder was then selected, and followed by the measurement of the water-resistance and absorption, impact resistance and thermal conductivity of the prepared FAAG. X-ray diffraction was also involved to identify the phase formation within the samples. Finally, the environmental impacts related to the preparation of 1 kg FAAG were obtained. Results shows that a type of more sustainable FAAG compared with the commercial product was successfully developed in low-temperature, revealing the low thermal conductivity of ~0.13 W/(m∙K) with a density of ~0.59 g/cm3 and compressive strength of ~5.52 MPa, which is 97% higher than the commercial product. Meanwhile, in addition to a foaming agent, aluminum powder is also acting as a key component in the geopolymerization of samples, facilitating the formation of aluminosilicate that provides strength.

Porous yttria-stabilized zirconia ceramics with low thermal conductivity via a novel foam-gelcasting method

In this work, the preparation of foam-gelcasting was simplified with a copolymer of isobutylene and maleic anhydride (Isobam), avoiding the traditional gelling system including many additives such as monomer, cross-linking agent, initiator and catalyst. Highly porous yttria-stabilized zirconia (YSZ) ceramics with 76.2–84.9% porosity were prepared via foam-gelcasting method using YSZ powder as the raw material, Isobam as the dispersant and gelling agent, triethanolamine lauryl sulfate as the foaming agent and sodium carboxymethyl cellulose as the foam stabilizing agent. The effects of solid loading, the content of foaming agent as well as sintering temperature were investigated. With the increase in solid loading of slurries, lower porosity was obtained, and the compressive strength and thermal conductivity showed a tendency of increase. Porous YSZ ceramics with compressive strength of 0.69–3.66 MPa showed low thermal conductivity in the range of 0.137–0.254 W/(m·K) at room temperature. The as-prepared sample showed good thermal insulating performance at high temperature. The km in GM model was during 0.4–0.7, which indicated the pore structure containing the internal and external porosities. This work provides a facile method for the fabrication of porous YSZ ceramics which can be potentially applied as thermal insulation materials at high temperature.

Study on Preparation and Performance Evaluation of Environment-Friendly Asphalt Mixture

In this paper, the environmental characteristics of foaming asphalt mixture are analyzed and the benchmark ratio is determined by Marshall test. Through the research on the production control parameters of mineral foaming and mechanical foaming, on the one hand, the optimal content of ZQ mineral foaming agent was determined to be 7%. On the other hand, The water consumption for mechanical foaming of SBS modified asphalt was set as 3.0±0.2%, the asphalt temperature was set as 165±2°C, and the water temperature was set as 30±2°C. At the same time, a method for determining the optimal content of mineral foaming agent based on asphalt modulus evaluation is proposed, and determine the influence degree of each factor of mechanical foaming based on grey correlation method. During the mixing test, the actual production was simulated, the samples were formed after the mixture aged for 2 hours in a short time, and the cooling range and performance of the foamed asphalt mixture were studied. The results show that the foamed asphalt mixture can reduce about 25°C compared with the hot-mixed asphalt mixture, and the performance of the mixture can meet the requirements of the current specification.

Effect of pore structure on mechanical and tribological properties of paper-based friction materials

To explore the effect of the pore structure of paper-based friction materials on the friction and wear properties, the composites with different pore structures were obtained using physical foaming technology. Results displayed that the bulk density and average pore size of composites increased after the foaming treatment, while the total pore area and porosity showed a tendency to gradually decrease after hot pressing. The tensile and interlaminar shear strength of the composites were improved by 18% and 42% respectively after the optimization of the pore structure. Moreover, the application of foaming technology significantly increased dynamic friction coefficient and reduced wear rate of the friction materials. In particular, the wear rate of paper-based friction materials decreased by 44.6% from 1.57x10−8 cm3/J to 0.87x10−8 cm3/J with the increase of foaming agent content. Most importantly, the pore structure of paper-based friction materials can be effectively changed due to the introduction of physical foaming technology. This research lays a solid foundation for optimizing the pore structure of paper-based friction materials in the future.

In-situ synthesis and properties of porous cordierite ceramics with adjustable pore structure

Using high purity oxide (MgO, Al2O3 and SiO2) as raw materials, porous cordierite ceramics with a single phase and adjustable pore structure have been in-situ synthesized by foam gel-casting process. The effects of sintering temperature and foaming agent concentration on the phase composition, microstructure and properties were systematically investigated. The results indicated that pure cordierite could be obtained at sintering temperatures of 1430 °C and 1450 °C, while the sample sintered at 1450 °C showed better comprehensive performance. By adjusting the foaming agent concentration in the range of 2–32 g/L, the pore size of the materials could be controlled between 45.3 μm and 151.3 μm with the total porosity of 85.4–87.8%. When the sintering temperature was 1450 °C and the foaming agent concentration was 8 g/L, the prepared samples showed excellent properties and the near net size sintering was achieved. The sintering linear shrinkage was about 0.26%, the total porosity was 86.6 ± 0.2%, the bulk density was 0.35 ± 0.01 g/cm3, the compressive strength was 2.63 ± 0.33 MPa, the thermal conductivity was 0.217 ± 0.026 W/(m·K), the thermal expansion coefficient was 1.70 × 10−6/oC, and the permeability of deionized water was 3.62 × 10−11 m2.

Foaming mechanism and optimal process conditions of foamed glass based on thermal analysis

The properties of foamed glass are substantially determined by interaction between glass and foaming agent during sintering process. Knowing the foaming mechanism and the influence of process conditions will help to reduce the defects of foamed glass. In this research, the TG–DSC–DTG thermal analysis was used to investigate the thermal behavior of waste glass, graphite (foaming agent) and their mixture to explore the foaming mechanism, as well as the effect of process conditions on the properties of foamed glass was discussed. Results indicate four stages in the weight-loss can be distinguished during the heating process: (I) 25–300 °C, (II) 300–450 °C, (III) 450–748 °C and (IV) above 748 °C. The (IV) stage between 748 and 909 °C is the main stage of foaming. Foaming temperature, holding time, foaming agent content and milling time have difference effects on the properties of foamed glass. Foaming temperature and holding time mainly affect the distribution of pores and average aperture respectively. The thickness of the pore wall and density of the foam are determined by foaming agent content, while milling time can control the quality of foamed glass by affecting the particle size of the mixture. The foamed glass showed the best properties when the mixture with 2 wt% foaming agent was sintered at 880 °C for 10 min after milling for 2.5 h.

Open‐cell porous sound‐absorbing ceramics prepared by a new procedure that combines foamed and templated methods

AbstractLow‐grade nonmetal ore, mainly magmatic soil and tuff, was used to prepare porous sound‐absorbing ceramics. A new processing method that combines the foaming and templating methods was used to produce open‐cell porous ceramics. Silicon carbide and carbon powders were used as the foaming agent and template agent, respectively, and their effects on open‐cell preparation and sound‐absorption properties were also investigated. The results showed that sound‐absorption performance was closely related to the apparent porosity (H). Compared with either foaming or template methods, the new method incorporating both processes increased the sound‐absorption coefficient (α) and H by 51%‐258% and 69%‐728%, respectively. Optimum sound absorption of the ceramics, that is, α = 0.68, noise reduction coefficient (NRC) = 0.48, and H = 50.22%, were obtained at foaming agent contents (FACs) of 1.5 wt% and template agent contents (TACs) of 4 wt%. The Delany‐Bazley and Voronina models were selected to simulate the sound‐absorption coefficients and the latter one fitted well with our experimental results.