Foam Stability Research Articles

Improving foam stability: Calcium addition, high hydrostatic pressure, and their combinations on soybean protein isolates

Various combinations of high hydrostatic pressure treatment (HHPT, 0.1 or 600 MPa), calcium addition (0, 0.50, or 0.75 mmol CaCl2/g protein), and protein content ([Prot.], 1, 5, or 10 g/L) were applied to soybean protein isolate (SPI) dispersions to analyze their effects on the formation and stability of foams. The significant interactions between these factors led to several combinations that improved foam stability via different mechanisms that involved different solubilities, aggregate sizes, and molecular structures of proteins. Thirty min after foam formation, calcium combined with HHPT improved volume of foam (VF30) and volume of liquid retained (VLr30), by the formation of strong interfacial films owing to the increased cross-linking ability of soluble and intermediate-sized aggregates. Calcium without HHPT had a greater effect on VLr30 than on VF30, which could be owing to the insoluble and large aggregates that blocked Plateau borders. HHPT without calcium led to small denatured aggregates that were soluble and improved the VLr30 when [Prot.] was lower. Industrial relevanceCalcium enriched plant proteins with good techno-functional properties is a prevailing need, considering the current cultural, economic and environmental changes that occur. The findings of this study could serve as an input for the incorporation of high biological value proteins and calcium into aerated foods, and would contribute to develop innovative products. Treatment with high hydrostatic pressure could be advantageous on account of modifying the protein structure and thereby improving the stability of the foams. Under certain conditions, such as those of aerosol whipping creams, high hydrostatic pressure would simultaneously improve techno-functional properties of proteins and pasteurize the dispersions, which would then have to be safely canned.

Dietary supplementation of black cumin (Nigella sativa) meal in the formulation of protein-enriched cookies, further invivo evaluation of protein quality with physicochemical and organoleptic characterization.

Nigella sativa has solid historical importance as a medicinal herb and is widely used in the bakery industry. The study revealed that the defatted black cumin meal (DBCM) possesses a high nutritious composition and amino acid profile, such as Leu, Lys, Arg, Phe, and Glu. The supplementation effect of wheat flour with defatted black cumin meal (DBCM) at levels of 5%-25% was explored on the cookies' nutritional, functional, and organoleptic attributes. Moreover, the present work was conducted to assess the invivo protein quality of defatted black cumin meal (DBCM)-supplemented cookies using the albino rat's experimental modeling for 10 days. Rheological characterization suggested a solid elastic behavior for all cookies dough with elevation in G' (138,652-230,926 Pa), G" (34201-45,092 Pa), and G* values due to protein addition. The functional characteristics of the flour blends showed that DBCM addition significantly (p ≤ .05) improved oil (70.56%-165%) and water (84.83%-232.67%) absorption capacities, emulsion, and foaming stability. The physicochemical and organoleptic assessment of the cookies exposed that a 20% level of substitution of DBCM produced acceptable cookies. The net protein utilization (NPU), protein efficiency ratio (PER), true digestibility (TD), and biological value (BV) significantly differ from each other among all the supplementation diet groups with 0%-25% DBCM.

QbD Approach in Cosmetic Cleansers Research: The Development of a Moisturizing Cleansing Foam Focusing on Thickener, Surfactants, and Polyols Content.

Cleansing products, particularly innovative cosmetic foams, must efficiently remove impurities with minimal impact on the skin barrier and have a favorable sensory profile. The choice of product ingredients is crucial to ensure the optimal characteristics. The current study aims to provide a comprehensive framework for understanding the variability in the characteristics of a cleansing foam to achieve desired properties. The novelty of this study lies in the combination of ingredients for their potential synergistic and complementary effects in cleansing dry skin, as well as the application of Quality by Design (QbD) elements to develop and optimize the formulation of cleansing foam. The effects of varying the concentration of mild surfactants, polyols, and gel-forming agents on the properties of the gels and of the generated foams were studied. Significant influences of the formulation factors were observed: an increased ratio of xanthan gum positively impacted the texture properties of the gel, whereas higher concentrations of surfactants had a negative impact on these parameters. Additionally, increasing the polyols ratio was found to negatively influence the foaming property and stability of the foam. The study established an optimal formulation of a cleansing foam with a ratio of 0.45% xanthan gum, 26.19% surfactants and 2.16% polyols to be used for dry skin hygiene.

Glucose-induced glycation enhances the foaming properties of Trichosanthes kirilowii seed protein isolate: Insights into structure, interfacial behavior, and proteomics

Improving the foaming properties of plant proteins has recently attracted particular interest. The foaming properties of Trichosanthes kirilowii seed protein isolate (TPI) after glucose glycation (wet heating) were investigated by structural characterization, interfacial behavior evaluation, and quantitative proteomics analysis. The results showed that the highest degree of grafting of TPI (45.54%) with glucose was observed at a reaction time of 2 h. Grafting with glucose unfolded the structure of TPI, which was confirmed by increased molecular flexibility, loss of α-helices, and exposure of hydrophobic groups. The foaming capacity and foaming stability of the TPI was greatly improved after glycation. The bubbles in the TPI–glucose conjugate foams were smaller in size, more uniform, and denser than those in the TPI foams. Moreover, the deterioration rate of the conjugate foams was significantly slower than that of the TPI foams. Mechanistically, the improved foam properties were mainly attributed to increased surface activity, accelerated air/water interfacial adsorption, and enhanced interfacial film thickness. The results of quantitative proteomics indicated that several proteins involved in foam stability and elasticity were upregulated in the initial foams of the conjugates, which partly explains the improved foam properties. Overall, G2 showed the most superior foam properties and interfacial behavior among all the samples. This study offers further insights into the mechanisms by which glycation improves the foaming properties of plant proteins and will be useful for the development of foamed foods from TPI.

Characterization of aqueous foams of alkyl polyglycoside, GreenZyme, alpha-olefin sulfonate, and cetyltrimethylammonium bromide in the presence of divalent ions

In this study, the impacts of divalent ions (calcium and magnesium) on aqueous foam stability and its rheological properties are investigated. A biodegradable surfactant of alkyl polyglycoside, (APG) and a commercial enzyme (GreenZyme, GZ) are used and their performance were compared with synthetic surfactants of alpha-olefin sulfonate (AOS) and cetyltrimethylammonium bromide (CTAB). The findings of the study revealed that the stability of all foams decreased with increasing concentrations of divalent ions, GZ recorded the lowest foam stability in the presence of the two ions and precipitation occurred in the AOS solution. On the other hand, foams generated by APG achieved the highest stability and the foams generated by CTAB showed the second highest stability among the foaming agents. Through rheological analyses, APG and CTAB exhibited shear thinning behaviour and their behaviour were modelled using a power law model in which the model can incorporate the effects of temperature and salinity.

Effect of high pressure processing on the structural and functional properties of the protein in corn gluten meal

ABSTRACT The presentation of high pressure processing (HPP) on corn starch has been reported, but the effect on protein in corn gluten meal (CGM) is rarely explored. The purposes of this study were to investigate the effect of HPP treatment on structural and functional properties of the protein in CGM. Protein was treated at 200–600 MPa for 5–15 min. Results showed that HPP treatment increased protein solubility, water and oil binding capacities, emulsion stability, foaming and foam stability. Protein which treated at 400 MPa for 15 min had the more enhanced functionality. Moreover, under this condition, the protein aggregates gradually dissociated, and the particle size decreased. These results indicated that the functional groups and structure of CGM protein were affected by the HPP treatment. We hope to convert an underutilized material into a valuable one through HPP in food industry.

Thermal stability of flexible polyurethane foams obtained from reactive phosphorus-containing polyols dispersed in polyethylene glycol

Thermal stability of flexible polyurethane foams obtained from reactive phosphorus-containing polyols dispersed in polyethylene glycol

Flammability, Toxicity, and Microbiological Properties of Polyurethane Flexible Foams.

The aim of the research was to investigate the influence of calcium phosphinate (HPCA) and aluminum phosphinate (HPAL) in synergistic systems with organophosphorus compounds, i.e., diphenylcresyl phosphate (CDP) and trichloropropyl phosphate (TCPP), on the thermal stability, flammability, smoke density, and emission of toxic gases during the thermal decomposition of polyurethane (PUR) foams. Thermogravimetric analysis (TGA), along with cone calorimetry and microcalorimetry, were used to assess the influence of fillers on the thermal stability and flammability of PUR foams. The analysis of toxic gas products was performed with the use of a coupled TG-gas analyzer system. The optical density of gases was measured with the use of a smoke density chamber (SDC). The obtained results showed an increase in thermal stability and a decrease in the flammability of the PUR composites. However, the results regarding smoke and gas emissions, as well as toxic combustion by-products, present ambiguity. On one hand, the applied flame retardant systems in the form of PUR-HPCA-CDP and PUR-HPCA-TCPP led to a reduction in the concentration of CO and HCN in the gas by-products. On the other hand, they clearly increased the concentration of CO2, NOx, and smoke emissions. Microbiological studies indicated that the obtained foam material is completely safe for use and does not exhibit biocidal properties.

Comparison of recombinant protein Z with natural protein Z derived from malt: From structure to functional properties

Protein Z (PZ) is a prominent albumin found in the endosperm of barley seeds with a molecular weight of approximately 40 kDa. Its multifaceted functional attributes, including trypsin- and thrombin-inhibiting bioactivities and superior foaming properties, have garnered significant attention in research. Considering the post-translational modifications of PZ natural in barley malt, we tried to express recombinant protein Z (rPZ) in E. coli. The present study aims to undertake a comparative analysis between natural PZ and rPZ in order to elucidate their respective characteristics. After spectral analysis, there are significant differences in their secondary and tertiary structures. In addition, rPZ showed superior foamability and foam stability. As for the serpin-like activity, the inhibition rate of rPZ is much higher than that of PZ. In contrast with the inhibition activity, the digestability of rPZ is much lower than that of PZ. As for the cargo carrier properties, rPZ showed an excellent ability to stabilize astaxanthin at 37 °C. These results suggest that rPZ is more suitable as protein carrier, due to the high foamability, serpin-like activity and low digestive stability, which not only give a brief view of recombinant protein, but also give a direction for PZ in cargo delivery.

Improving foamability and foam stability of poly(ethylene terephthalate) through chemical modification with styrene maleic anhydride

Improving foamability and foam stability of poly(ethylene terephthalate) through chemical modification with styrene maleic anhydride

Enhancing the engineering performance of lightweight limestone calcined clay cement concrete using used engine oil as a foam stabilizer

Lightweight foam concrete is an appealing thermal insulation material with great potential for decarbonizing the building sector, given that its superior thermal insulation and reduced material usage promote energy-efficient and low-carbon constructions. However, traditional foam concrete largely depends on carbon-intensive ordinary Portland cement (OPC) and costly foam stabilizers, e.g., nanomaterials. To address these issues, this study developed an eco-friendly foam concrete formula incorporating limestone calcined clay cement as a low-carbon cement substitute and used engine oil (UEO) as a foam stabilizer. The viability of this formula was confirmed by assessing foam stability performance of UEO-enhanced foam and crucial engineering performance – thermal conductivity and compressive strength – of foam concrete. Experiments demonstrate that 1 % UEO notably boosts foam stability, with prolonged stable time by 75 % and enhanced remaining foam fraction by 43 %. Additionally, 1 % UEO-containing foam concrete exhibits superior compressive strength of 3.2 MPa and reduced thermal conductivity of 0.162 W⋅m-1K-1, outperforming foam concrete without UEO. The mechanisms of macroscopic performance changes were revealed through scanning electron microscopy (SEM), which disclosed a uniformly established UEO-enhanced pore system and UEO-driven hydration process as the microscale origins. These findings provide waste-enhanced foam stabilizers and present an environmentally appealing alternative to traditional foam concrete, with implications for clean waste management and building decarbonization.

Applicability of cationic surfactants, anionic surfactants, and nonionic surfactants as foaming agents for foamed concrete: surface activity, foamability, and interaction with cement

Selecting the appropriate surfactant as a foaming agent is crucial in the production of foamed concrete. In this study, multiple technological approaches were employed for the investigation of the effect of three different types of surfactants as foaming agents; the approaches included surface tension measurement, zeta potential analysis, spectrophotometry, and nanoindentation. The results showed that the surface activity, solution viscosity, and environmental pH all influenced the generation and stability of foam in foaming agents. The adsorption process of surfactants onto cement particles was complex and could be effectively explained using the double-layer theory. The adsorption of anionic surfactant molecules on cement particles significantly altered the zeta potential, up to −17 mV, with an adsorption efficiency over 10 times greater than that of cationic surfactants and more than 5 times greater than that of nonionic surfactants. Furthermore, after cement hardening, the mechanical properties of the resulting pores were notably improved due to the presence of adsorbed anionic surfactants, and the maximum compressive strength could exceed 10 MPa.

A non‐ionic green surfactant extracted from the Anabasis setifera plant for improving bulk properties of CO2‐foam in the process of enhanced oil recovery from carbonate reservoirs

AbstractFoam, as a gas‐in‐liquid colloid, has a higher appearance viscosity than the one of both gas and liquid that form it. Adjusting the mobility ratio of the injected fluid–oil system and increasing gas diffusion in the foam injection process increase oil production. With these properties, foam as an injection fluid in fractured reservoirs has a major effect on oil production from the matrixes and prevents premature production of injection fluid. Surfactants are common foaming agents in injection water. Saponins are known as plant‐derived surfactants for forming stable foam. This feature, along with its cheap price and availability, can make them candidates for enhanced oil recovery (EOR) by the foam injection method. However, the utilization of CO2 as the gaseous phase in foam introduces additional machanisms of CO2 injection to the oil recovery operations. In this assessment, a non‐ionic green surfactant derived from the Anabasis setifera plant was used as a foaming agent, while CO2 served as the gas phase. A series of surface tension tests in CO2 environment were performed to determine the optimal concentration of the surfactant. Foaming tests were performed by a designed foam generator. The produced CO2‐foam was then injected into a fractured carbonate plug with six matrixes (with one horizontal and two vertical fractures). Based on the results, the water–CO2 surface tension was reduced to 20.549 mN/m. The optimum salinity based on the foam stability was 10,000 ppm. The half‐life of the foam was determined to be 40 min. Also, the foam characterization showed that the foamability of the surfactant was favourable for increasing oil production so that by secondary flooding, an oil recovery of more than 66% was achieved from the fractured carbonate plug.

The Effect of the Proportion of Rubber Components on the Properties of EVA/SBR/BR Foams

In actual production processes, pure ethyl vinyl acetate (EVA) foams have a high shrinkage rate, and the foaming matrix is prone to plastic deformation, even causing the collapse of bubbles. This limits the further application of EVA foams. In this study, we incorporated styrene butadiene rubber (SBR) and butadiene rubber (BR) into EVA to improve the mechanical properties and dimensional stability of EVA composite foams without sacrificing their low-density characteristics of low density. We used a melting index meter, rotorless vulcanizing meter and dynamic mechanical analysis (DMA) to characterize the changes in viscosity and energy storage modulus of the composite matrix. Scanning electron microscopy (SEM) was used to study the microscopic morphology of foams. The mechanical properties test results showed that the addition of SBR reduced the density of EVA/SBR/BR composite foams, and the addition of BR improved the mechanical properties and dimensional stability of the foams. By combining the advantages of both, the density of products is comparable to pure EVA, the tensile strength and the compressive strength are increased by 11% and 6.3% relative to pure EVA, respectively.

Xanthan gum short-chain modified TiO2 nanoparticles for the preparation of high-stability foam to effectively improve the efficiency of foam oil repulsion

Nanoparticles excel in foam stability enhancement. In this experiment, xanthan gum (XG) short links were branched on the surface of TiO2 nanoparticles, and the synthesis of novel nanomaterials was verified by analyzing the structure of the nanoparticles by FT-IR, XRD, and XPS, and investigating the dispersion of the nanoparticles by using SEM as well as capturing the cross-sectional images of XG-TiO2 by using TEM and performing elemental analyses. The foams prepared by using cationic surfactant Cetyltrimethylammonium bromide (CTAB) and XG-TiO2 synergistically had excellent performance, and XG-TiO2 was able to effectively prevent the disproportionation reaction of the foams. By adding hydroxide and changing the air pressure, the half-life and foaming volume of the prepared foams were compared and analyzed, and the half-life of the foams was more than twice as much as that of the traditional materials, and the foam morphology of the foams with XG-TiO2 was smaller and more homogeneous. When XG-TiO2 foam was tested for core drive, the total crude oil recovery reached 81.2 %, which was 45.4 % higher than the water drive recovery. This experiment demonstrated the potential of XG-TiO2 nanoparticles in enhancing foam stability and foam drive application.

Hierarchically porous bone scaffold fabricated via direct foam writing with TCP/ZrO2 composite ink

Customizing bone scaffolds to mimic the hierarchically porous structure of natural bone presents a promising strategy for treating critical bone defects. Although low-cost direct ink writing (DIW) is often used to customize bone scaffolds, the limited print resolution made it difficult to print microporous structures. In this study, DIW was combined with the direct foam method to construct bone scaffolds with hierarchical and interconnected macro-micro porous structures. The foam stabilization mechanism of pure TCP was investigated to prepare TCP-enhanced ZrO2-based composite foam inks. Incorporating TCP endowed a richer interconnection structure to the composite foam. The printed bone scaffolds feature three scales of pore structure: interconnected macropores of 400–500 μm, bubble template pores of 50 μm, and open pores of <20 μm. The scaffold exhibited properties comparable to cancellous bone, such as 90 % porosity, 3.1 MPa compressive strength, and 1.0 GPa elastic modulus. In vitro experiments have demonstrated that cells can grow into the interior of the scaffold by following the connecting pores. And, incorporating TCP significantly enhances osteogenic protein and gene expression in bionic bone scaffolds. This facile and controllable approach offers an alternative solution to addressing the challenge of clinical implant shortages.

Foam drainage agent with enhanced foam stability through modified Fe3O4 nanoparticles

A nanofoam drainage agent was developed to address the challenges of inadequate foam stability and foaming efficiency in the gas recovery process of foam drainage. The formulation of the primary foam drainage agent was obtained by screening and combining conventional anionic and amphoteric surfactants. Experimental results revealed a synergistic interaction between α-olefin sulfonate (AOS) and lauramidopropyl betaine (LAB-35). Specifically, when a mixture of 0.4 wt.% AOS and 0.1 wt.% LAB-35 was used, the surface tension of the primary foam drainage agent was measured to be 23.32 mN/m. Furthermore, modification of Fe3O4 nanoparticles with the silane coupling agent γ-(methacryloxy)propyl trimethoxysilane (KH-570) was performed to improve the dispersibility in aqueous solutions and enhance foam stability. The results of infrared spectroscopy, x-ray diffraction, thermogravimetric analysis, and contact angle measurements revealed the effective bonding of KH-570 to the surface of Fe3O4 nanoparticles. Additionally, the particle size distribution in the aqueous solution showed the excellent dispersion of the modified Fe3O4 nanoparticles. Through the incorporation of the modified Fe3O4 nanoparticles into the primary foam drainage agent, a nanofoam drainage agent with a half-life of 989 ± 6.5 s was developed. Microscopic observations of foam coarsening behavior revealed the mechanism behind foam stability. Performance testing of the foam drainage agent demonstrated the agent’s outstanding resistance against salinity, temperature, and oil and its remarkable liquid-carrying capacity.

An Experimental Investigation of Surfactant-Stabilized CO2 Foam Flooding in Carbonate Cores in Reservoir Conditions

Carbon dioxide (CO2) injection for enhanced oil recovery (EOR) has attracted great attention due to its potential to increase ultimate recovery from mature oil reservoirs. Despite the reported efficiency of CO2 in enhancing oil recovery, the high mobility of CO2 in porous media is one of the major issues faced during CO2 EOR projects. Foam injection is a proven approach to overcome CO2 mobility problems such as early gas breakthrough and low sweep efficiency. In this experimental study, we investigated the foam performance of a commercial anionic surfactant, alpha olefin sulfonate (AOS), in carbonate core samples for gas mobility control and oil recovery. Bulk foam screening tests demonstrated that varying surfactant concentrations above a threshold value had an insignificant effect on foam volume and half-life. Moreover, foam stability and capacity decreased with increasing temperature, while variations in salinity over the tested range had a negligible influence on foam properties. The pressure drop across a brine-saturated core sample increased with an increasing concentration of surfactant in the injected brine during foam flooding experiments. Co-injection of CO2 and AOS solution at an optimum concentration and gas fractional flow enhanced oil recovery by 6–10% of the original oil in place (OOIP).

A novel approach for nanobubble generation toward biomedical applications

The stability of free-standing nanobubbles is a long-standing controversial problem due to the Laplace pressure catastrophe at the nanoscale. In most industrial circumstances, a large quantity of surfactants is required as stabilisers or emulsifiers to generate stable bubbles or foams. However, when surfactants exceed a certain level, they can adversely affect living organisms and pose environmental risks. Towards biomedical use, we investigated nanobubble generation through a mini-extruder in amino acid solutions. Herein, we considered glycine (having two acid dissociation constants, i.e. pKa values) and lysine (having three pKa values) as two model amino acids, conducting experiments with various concentrations (0.1 M, 0.5 M and 1 M), along with different pH values (above, equal to, and below the isoelectric points of each amino acids; 5.97 for glycine and 9.74 for lysine). Our results showcased the proof of concept that amino acids can stabilise nanobubbles in bulk for a few days. We achieved remarkable products of nanobubbles via nanopores by extrusion, with reproducible size distribution and stability. We also compared the extrusion protocol with the commonly used ultrasound method. It turned out that extrusion generated samples with smaller sizes and higher concentrations than sonication. This study provides a reliable protocol for generating small-scale nanobubbles for biomedical use, showing great potential in drug delivery for medical treatment.

Structural and functional assessment of keratin extracted from chicken feathers using microwave-assisted l-cysteine method

Extracting and applying waste feather keratin are important environmental challenges. This study utilized microwave-assisted l-cysteine treatment on chicken feathers, pH adjustments varied reducing capacity of l-cysteine, while modulated microwave power explored synergistic extraction effects on properties of keratin. The highest yield of regenerated keratin was achieved at an l-cysteine concentration of 15 g/L, pH 12, and a microwave power of 400 W. Micromorphological and particle size results revealed that the keratin particle size increased with pH dependency, the highest proportion of particle size values in keratin increasing from 164 nm in L1 (extracted at pH 11) to 220 nm in L5 (extracted at pH 13). Increasing the intensity of both treatments led to a transition of the secondary structure of regenerated keratin from α-helix to β-sheet, but the increasing reducibility of the system resulted in a decrease in the content of tryptophan residues in keratin, whereas the increase in microwave power led to the masking of some fluorescent chromophores within the keratin. The regenerated keratin demonstrated low crystallinity, and it may have undergone refolding and aggregation under microwave-assisted highly reducing extraction conditions. The foaming properties indicated that the highly reducing extraction system significantly decreased foam stability from 95.4% for L1 to 19.8% for L5 (p < 0.05) and improved foaming ability to keratin. Considering the widespread applications of keratin, this study provides a comprehensive characterization of regenerated keratin under different extraction conditions, aiming to offer experimental materials and extraction conditions tailored to specific requirements in the field of biomaterials.