Foam Control Research Articles

Hydrophobicity of Benzene-Based Surfactants and Its Effect on Bubble Coalescence Inhibition

Bubble coalescence plays a critical role in optimizing biological and industrial processes, impacting efficiency in areas such as fermentation, wastewater treatment, and foaming control. While the relationship between chemical structure and bubble coalescence has been thoroughly explored for inorganic ions, limited data exist on organic ions and surfactants, despite their widespread use in these industries. This study addresses this gap by investigating the effects of surfactant hydrophobicity and bubble size on coalescence behavior at a flat air–liquid interface and within a bubble column. Surface tension measurements were employed to assess surfactant hydrophobicity, while bubble size and coalescence time were analyzed to determine their respective influences. The results reveal a novel quantitative relationship between surfactant hydrophobicity and the half-coalescence inhibition concentration (HCIC), a new variable introduced in this study. This relationship demonstrates that as hydrophobicity increases, the HCIC also rises, providing a new relationship between surfactant hydrophobicity and bubble coalescence. While it is well-known that more hydrophobic molecules delay coalescence, this is the first time a direct, proportional relationship has been established with HCIC, offering a new parameter for predicting and controlling coalescence phenomena.

Active vibration control of metal foam reinforced agglomerated graphene nanoplatelets nanocomposite truncated conical shells with piezoelectric layers

This study examines active vibration control (AVC) in a truncated conical shell composed of metal foam reinforced with agglomerated graphene nanoplatelets and integrated with piezoelectric layers functioning as sensors and actuators. Both complete and partial agglomeration states are considered based on the Eshelby–Mori–Tanaka approach, and the mechanical properties of the porous core are characterized using a closed-cell metal foam model. The governing equations of motion are derived using Hamilton’s principle, based on the two-dimensional axisymmetric elasticity theory, and solved through the finite element method coupled with the Newmark method. Vibration mitigation is achieved using a fractional-order fuzzy proportional–integral–derivative (PID) controller. A comprehensive parametric study is conducted, examining the effects of geometric dimensions, various boundary conditions, reinforcement parameters (including weight fraction, distribution patterns, and agglomeration parameters), and porosity parameters (including pore size, and porosity pattern) on the vibration properties of the shell. Numerical simulations are performed to assess the effectiveness of the proposed AVC system in reducing structural vibrations compared to a constant velocity feedback control approach. The velocity feedback controller reduced central deflection from 12.65 to 5.089 μ m , while a fractional-order fuzzy PID controller further improved it to 2.348 μ m , representing a 53.86% enhancement over the velocity feedback controller.

Foam detection in a stirred tank using deep learning neural networks

A deep learning method based on the Convolutional Neural Network (CNN) U-Net architecture has been explored as an image analysis tool for the detection and automated quantification of foam generated in a stirred tank. Multiple datasets of different sizes and with different types of foam were obtained experimentally and processed with data augmentation techniques in order to train the deep learning networks. The impact of adding attention and residual gates to the U-Net model to improve its performance, as well as the size of the dataset used to train the model have been assessed. The main factor influencing the accuracy of the models to detect the foam in the stirred tank is the size and quality of the dataset use to train the U-Net models; it must be sufficiently large and varied in terms of foam type/structure. The addition of attention gates and residual blocks to the U-Net model slightly improves the accuracy of foam detection, particularly for images that contain additional objects or obstructions, however the training time is 30 % longer than the standard U-Net model. In all cases, this image analysis method based on the U-Net model largely out performs conventional image analysis, which was not able to automatically differentiate between foam, additional objects in the tank and bubbles in the liquid. Two methods for the measurement of foam quantity (maximum foam height and foam volume) have also been developed based on the foam regions detected by the models. This is important for the application of the tool, which is to be used to understand the impact of operating conditions on foam formation in lab-/pilot-scale stirred tanks and then develop scale-up guidelines for foam control in industrial tanks.

Mechanism of sodium lauryl sulfate reducing froth stability of dodecylamine in hematite flotation: Experiments and molecular dynamics simulation

In this study, the influence of sodium lauryl sulfate (SLS) on the stability of dodecylamine (DDA) froth during the reverse flotation of hematite was investigated due to the frequent issue of excessively viscous foam leading to suboptimal reverse flotation outcomes. The research involved conducting flotation tests and two/three-phase froth stability assessments to explore how a specific molar ratio combination of DDA and SLS could enhance the flotation performance while simultaneously mitigating froth stability. The investigation into the mechanism by which SLS reduces the stability of DDA froth was aided by molecular dynamics simulations. The findings revealed that in the collector system comprising DDA and SLS, several key changes occurred at the molecular level. These included a decrease in the thickness of the electric double layer at the interface, a reduction in the thickness of the gas–liquid interface layer, weakening of the interaction strength between the head group and water molecules, a decrease in the coordination numbers of water molecules in the first hydration layer, and an enhanced migration ability of water molecules. Furthermore, there was an increased inclination angle between the head groups or molecular chains of the collector and the Z-axis, resulting in a diminished interaction depth between the head group and water and a closer positioning of the molecular tail chain to the gas–liquid interface with a more pronounced curvature. Consequently, these molecular adjustments led to a sparser arrangement of DDA molecules at the gas–liquid interface, lower coverage of the interface adsorption layer, and increased gas permeation, ultimately reducing DDA froth stability. The aforementioned conclusions provide a comprehensive molecular-level analysis of the principal mechanisms that can effectively reduce foam stability, including the attenuation of molecular head group-water interactions, reduction in gas–liquid interface layer thickness, decrease in gas–liquid interface orderliness, and enhancement of water molecule migration capability. The implications of this research extend to providing theoretical insights for addressing foam control challenges in DDA flotation processes.

Structural control and mechanical properties optimization of porous SiC foams with three-dimensional network structure

In this paper, a new process for preparing porous SiC foam with three-dimensional network structure is presented. A certain thickness of SiC coating is deposited on the surface of ultra-light carbon skeleton by CVD process, so as to achieve effective control of its structure and mechanical properties. The effects of CVD deposition time on the density, porosity and skeleton thickness rates of SiC foams were explored. By increasing the CVD deposition time, the structure of SiC foams can be effectively regulated, and the mechanical properties of SiC foams can be significantly improved. The porosity of the prepared SiC foam can be adjusted in a wide range (26.9%∼94.68%). When the density of SiC foam increases from 0.67 g/cm3 to 2.36 g/cm3, its bending strength increases from 27.4 MPa to 136.9 MPa, which is significantly improved. After high temperature oxidation treatment (800–1200 °C), the mechanical properties of SiC foam will be further improved. However, when the oxidation temperature reaches 1400 °C, its mechanical properties will be reduced. This research provides a new idea for the preparation of high-performance porous SiC ceramics, and lays a foundation for its structural design, manufacture and application.

Enhancing stability and odor control of water-based foam for pesticide site restoration using xanthan gum

Foam stability plays an important role in the effect of blocking the odorous substances. Based on the characteristic of xanthan gum of enhancing foam stability and preventing foam from water drainage and coarsening, this paper investigated the half-life, foaming volume, viscosity, drainage curve, and bubble microstructure of foam filled with 0.1%, 0.2%, and 0.3% xanthan gum respectively, and further analyzed the correlation between xanthan gum dosage, viscosity of foam solution and foam stability. The effect of different stability foams on para-xylene was tested. The results showed that compared with no xanthan gum, the half-life of foam with 3% xanthan gum was extended from 1 to 61 h, the drainage time increased from 4.5 to 85 h, and the foaming coarsening rate slowed down 3 times. The addition of 0.3% xanthan gum reduced the peak value of the p-xylene dispersion by 83.7% and postponed the peak time by 6 times.

Foam control in lakes and sewage receiving water bodies: A pre-emptive approach using decentralized inline water treatment design

Hideous and persistent foams on surface water bodies are global issues with far-reaching environmental consequences. This study examines Bellandur Lake (Bengaluru, India) plagued by foam since 2005 due to surfactant-laden untreated sewage ingress. Bellandur Lake receives 258 million liters of inadequately treated sewage daily, constituting 47% of its total volume. Yearlong water quality monitoring reveals that a) high surfactant levels (up to 17.8 ± 1 ppm) and b) prevalent anoxic conditions at lake inlets. Laboratory experiments show that controlled aeration achieved >90% surfactant degradation within 30 h at 3.5 ppm of dissolved oxygen conditions, indicating the need for an aeration chamber design based on the required residence time for inline water treatment. Based on these findings, a design of an inline wastewater treatment system to be installed at sewage entry points into the lake is presented in this work. The inline system was based on experimentally validated BioWin software. Simulations show that recirculating sludge enhances treatment efficiency, achieving effective surfactant degradation in 20 h (2/3rd original time) of residence time. Predictions suggest <1 ppm surfactant levels in the receiving water body, meeting local discharge norms to prevent frothing. This holistic approach, proposed for the first time, could serve as a blueprint for managing foam-related challenges in other waterbodies, offering insights into design, stakeholder engagement, and process optimization.

Measurement and control of foam generation in a mammalian cell culture.

Foam is generated in mammalian cell cultures by excessive agitation or gas sparging. This occurs particularly in cultures that generate recombinant proteins at high cell concentrations. Three antifoam agents were tested for their compatibility with antibody-producing Chinese hamster ovary (CHO) cells. One agent (antifoam 204) was completely inhibitory to growth at a concentration of 10 ppm, one agent (antifoam C) showed partial inhibition and a third (antifoam SE-15) showed no inhibition at this concentration. A novel foam image analyzer (LabCam) was used to evaluate two antifoams (C and SE-15) for their ability to dissipate foam generated in cell culture media by enhanced agitation. The presence of antifoam in the media reduced significantly the foam layer that was generated and this was shown to be rapidly dissipated in the presence of 10 ppm SE-15. The antifoams were also tested for foam dissipation in cultures of CHO cells at >106 cells/mL. Supplementation of the cultures with SE-15 resulted in dissipation of foam generated by excessive gas sparging within 2 min. Under equivalent conditions 75% of foam dissipated in the presence of antifoam C, within 2 min but there was a residual foam layer up to 25 min. This study showed the value of an optical monitoring system (LabCam) for measuring foam generation and dissipation in a bioreactor to assess the efficiency of antifoam agents to reduce foam in a bioreactor. This has the potential for use as a control system that could be designed for continuous monitoring and foam control in a mammalian cell bioprocess.

Thermodynamic study on the effect of foaming on the heat and moisture control ability of humidity control material

This study mainly investigates the effects and evaluation method of foaming on the thermodynamic treatment capacity of moist air of the humidity control materials. Firstly, the experimental results show that the foaming can increase the maximum adsorption to 1.2 times, the moisture buffering to 1.39 times, the water vapor permeability to 1.09 times, and the thermal insulation to 1.48 times, which indicates that foaming can help the humidity control materials have a better ability to treat the moist air and response the change of environment. Secondly, correlation analysis results indicate that foaming can change the pore structure, such as the specific surface area and average pore diameter, which are closely related to each properties. And the porosity also is a key parameter that can reflect the characteristics of the foaming materials. Thirdly, due to the decline of mechanical performance always come up with foaming, this study proposes a new evaluation method that can be used to compare the comprehensive performance of the foaming humidity control materials, so that this kind of foaming process can be used in buildings with different purposes. The new evaluation method, i.e., the dimensionless comprehensive performance evaluation method, its reliability and effectiveness can be verified by sensitivity analysis. In general, this work shows that the reasonable use of the foaming can be an effective way to improve the adaptability of hygroscopic materials, which can effectively control the indoor environment and help to achieve the goal of building energy conservation, and this study also can give the guides for the material design and optimization.

Synthesis and Characterization of a Titanium-Based Functionally Graded Material-Structured Biocomposite using Powder Metallurgy.

This investigation aims at synthesizing and characterizing a biocomposite of hydroxyapatite (HA) and titanium (Ti) as a functionally graded material (FGM) via an economical powder metallurgy route. Ti particles were produced through drilling and chipping, followed by compaction and sintering. Ti foams, so obtained, were then infused with varying volume fractions of HA. The pure Ti foam control sample and the FGM composite samples were then subjected to various characterizations to validate their biocompatibility, structural strength, and integrity. The interface development between the load-bearing Ti implant and living tissue was resolved through an FGM structure, where the base of the implant consisted of load-bearing Ti and the outer periphery changed to HA gradually. HA/Ti specimens of different volume fractions were tested for density measurements, microstructure, hardness, and bioactivity. The bioactive behavior was investigated using the potentiodynamic polarization technique to measure the corrosion rate of the pure Ti foam (0/100 HA/Ti) and the FGM composite (10/90 HA/Ti) samples in a simulated body fluid (SBF). The results showed that the hardness of FGM composites, despite being less than that of 0/100 HA/Ti, was still within safe limits. The corrosion rate, however, was found to be decreased by a significant value of almost 40% for the 10/90 HA/Ti FGM composite sample compared to the pure Ti foam control sample. It was concluded that the optimum composition 10/90 HA/Ti sample offers improved corrosion resistance while maintaining a sufficient allowable hardness level.

Performances of green velvet material (PLON) used in upholstered furniture

Green Velvet Material (PLON), which is prepared from polyester slices, has been called a green material based on its ester composition, its ability to be degraded, and the possibility of recovering the value of used material by reprocessing. PLON is expected to be used as a material for the padding layer of upholstered furniture. This paper presented a comparative study of traditional flexible polyurethane foam and Green Velvet Material as the upholstered furniture’s padding layer. The compression mechanical properties of Green Velvet Material and flexible polyurethane foam, such as indentation force deflection, support performance, compression set, and resilience property, were analyzed. The results showed that Green Velvet Material had lower surface hardness and higher comfort compared to flexible polyurethane foam. In terms of resilience, both high-density and low-density Green Velvet Material performed better than the foam control group, but Green Velvet Material had a poorer ability to regain its shape after prolonged pressure. The 30 kg/m3 density Green Velvet Material was the closest to the compression and resilience properties of flexible polyurethane foam. The conclusions provide theoretical data for the effective and reasonable application of Green Velvet Material in upholstered furniture.

Evaluating how avocado residue addition affects the properties of cassava starch-based foam trays

Avocado seed (AS) is an interesting residue for biopackaging because it has high starch content (41 %). We have prepared composite foam trays based on cassava starch containing different AS concentrations (0, 5, 10 and 15 % w/w) by thermopressing. Composite foam trays with AS were colorful because this residue contains phenolic compounds. The composite foam trays 10AS and 15AS were thicker (2.1–2.3 mm) and denser (0.8–0.9 g/cm3), but less porous (25.6–35.2 %) than cassava starch foam (Control). High AS concentrations yielded composite foam tray less puncture resistant (∼40.4 N) and less flexible (0.7–0.9 %), but with tensile strength values (2.1 MPa) almost similar to the Control. The composite foam trays were less hydrophilic and more water resistant than control due to the presence of protein, lipid, and fibers and starch with more amylose content in AS. High AS concentration in composite foam tray decreases the temperature of thermal decomposition peak corresponding to starch. At temperatures >320 °C the foam trays with AS were more resistant to the thermal degradation due to the presence of fibers in AS. High AS concentrations delayed the degradation time of the composite foam trays by 15 days.

Alternative reductants for foam control during vitrification of high-iron High Level Waste (HLW) feeds

Foaming during vitrification of radioactive waste in Joule-Heated Ceramic Melters (JHCM) is exacerbated by trapping of evolving gases, such as CO2, NOx and O2, beneath a viscous reaction layer. Foaming restricts heat transfer during melting. Sucrose is employed as the baseline additive at the Hanford site in Washington State, USA to reduce foaming. Alternative carbon-based reductant additives were explored in simulated, inactive Hanford high-iron HLW-NG-Fe2 feeds, for both their effect on foaming and to give insight to the behaviour of multivalent species in glass melts under different redox conditions. Graphite, coke (93% C), formic acid and HEDTA additives were compared with sucrose, and a feed with no additive. Graphite and coke additions proved most effective in reducing the maximum foam volume by 51 ± 3% and 54 ± 2%, respectively, compared with 24 ± 5% for sucrose. Lower foaming could result in more efficient vitrification in JHCMs. Reductants also affected redox ratios in the multivalent species present in the feed. The order of reduction, Mn3+/Mn2+ > Cr6+/Cr3+ > Ce3+/Ce4+ > Fe3+/Fe2+ was as predicted on the basis of their redox potentials. There is less reduction overall, particularly in the Fe3+ → Fe2+, than predicted by the calculations, attributed to the oxygenated atmosphere of the experiments.

A Prospective, Randomized, Non-inferiority Trial to Compare the Efficacy of 3% Povidone-Iodine Foam Dressing and Silver Foam Dressing in the Treatment of Pressure Injuries

Background: As chronic wounds such as pressure injuries (PIs) are frequently colonized and can easily deteriorate into infection, it is important to reduce their bacterial load, for which antimicrobial dressings can be needed. This study aims to evaluate the efficacy of a 3% povidone-iodine (PVP-I) foam dressing compared to that of a silver foam dressing.Methods: This prospective non-inferiority study was conducted between 2016 and 2019 at three sites in South Korea. A total of 80 PI subjects were randomized to be dressed with either PVP-I foam (experimental group) or silver foam (control group) for up to 8 weeks.Results: Based on the Pressure Ulcer Scale for Healing (PUSH) tool, 25.0% of the experimental groups and 17.5% of the control groups (χ&lt;sup&gt;2&lt;/sup&gt;=0.743, P=0.389) healed by more than 70%. The degree of reduction in wound size was analyzed using Image J, and the experimental and control groups decreased by 41.6%±35.3% and 49.7%±38.2% (t=–0.986, P=0.327), respectively. A Kaplan-Meier survival analysis to confirm the time to heal showed that if more than 30% of the PUSH score was healed, the time to heal was 27.0±9.3 days and 18.0±2.8 days in the two groups (χ&lt;sup&gt;2&lt;/sup&gt;=3.225, P=0.073), respectively. The healing rates at 50 days were 85.8%±8.9% and 93.9%±5.7% in the two groups (P=0.073), respectively. There were no statistically significant differences between the groups in all results.Conclusion: This study demonstrated the non-inferiority of the 3% PVP-I foam dressing compared to the silver foam dressing for PI treatment.

Chemical industry wastewater treatment by coagulation combined with Fenton and photo‐Fenton processes

AbstractBACKGROUNDChemical industry wastewater is challenging to treat because of the various chemicals they contain. In this study, the treatment of chemical industry wastewater, which produces a wide variety of chemical aids, such as foam control agents, and silicones used in the textile, food and cosmetics industries, by coagulation combined with Fenton or photo‐Fenton oxidation processes was investigated. In coagulation studies, optimum pH and coagulant dose were determined with polyaluminum chloride (PAC), polyaluminum chloride hydroxide sulfate (PACS) and FeCl3 coagulants, while Fe2+, H2O2, pH and oxidation time were optimized in Fenton studies.RESULTSIn the coagulation, higher wastewater treatment was achieved with PAC compared to PACS and FeCl3 coagulants, and 62.6% chemical oxygen demand (COD) and 44.3% total organic carbon (TOC) removal were obtained at 500 mg L−1 PAC and pH 8. In the coagulation and Fenton oxidation, 92.4% COD, 79.7% TOC, 99.8% turbidity, and 96.7% total soluble solids (TSS) were achieved. The application of photo‐Fenton oxidation instead of Fenton oxidation did not cause a significant change in chemical industry wastewater. The cost of chemical industry wastewater treatment by coagulation and Fenton oxidation was calculated as $19.16 m−3, and the cost per kilogram of CODremoved was determined as $2.89 kg−1.CONCLUSIONIn chemical industry wastewater treatment, high TSS and turbidity removal can be achieved by coagulation with PAC, and the wastewater load subjected to Fenton oxidation can be reduced. Efficient wastewater treatment was provided by Fenton oxidation after coagulation. The application of the photo‐Fenton oxidation process instead of Fenton oxidation did not show the expected effect. However, toxicity studies should be performed in treated wastewater using coagulation–Fenton oxidation processes in future studies. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley &amp; Sons Ltd on behalf of Society of Chemical Industry (SCI).

Safety and Effects of a Commercial Ozone Foam Preparation on Endometrial Environment and Fertility of Mares.

Mares' subfertility represents a complex diagnostic and therapeutic challenge and both clinical and subclinical endometritis are considered major causes of impaired fertility. Thanks to its properties, ozone has a big potential as a treatment for equine endometritis. Therefore, the aim of this study is to describe the safety and the effects on endometrium and reproductive parameters of mares of a commercial ozone foam preparation (Riger Spray®). Twenty-four mares were treated during estrus: ozone group with an intrauterine instillation of ozone foam preparation (OG, n=16) and control group with 20 ml of lactated Ringer's solution (CG, n=8). Samples for endometrial cytology were collected before the ozone treatment (T0), after 24 h (T1), after one week (T2), two weeks (T3), and when the subsequent estrous phase was detected (T4). Furthermore, samples for histological examination and uterine swab for bacteriological examination were collected at T0 and T4. At T1, a statistically significant increase of endometrial inflammation in the OG mares compared to T0 (P<.05) and to CG at same time point (P<.05) was observed, but it was already resolved at T2. No differences in endometrial inflammation in CG, biopsy grade before and after the treatment in the two groups, number of mares pregnant at the end of the season and number of mares pregnant at the first cycle were observed. However, the number of inseminations required for pregnancy tended to be lower (P=.0711) in the OG (1.69±0.06) than in CG mares (2.60±0.89).

Enhanced fermentation of biosurfactant mannosylerythritol lipids on the pilot scale under efficient foam control with addition of soybean oil

Biosurfactant mannosylerythritol lipids (MELs) are green alternatives to chemically synthesized surfactants. However, these biosurfactants typically have a high cost-of-production limiting their adoption for industrial applications. In this study, an optimized fermentation process at pilot scale to furnish MELs with Pseudozyma aphidis DSM 70725 was developed. This involved the optimization of the levels of Fe2+, Fe3+ to improve the fermentation efficacy and the use of soybean oil to reduce the foam generated during fermentative production of MELs. The MELs titer, production rate and the conversion ratio of the carbon source was enhanced to 61 g/L, 0.255 g/L/h and 0.68 g/g, respectively. These optimizations resulted in approximately 100% improvement over regular fermentation processes and are amenable to the large-scale fermentation of MELs employing soybean oil as an antifoam agent to overcome foaming issues.

High porosity PEG-based hydrogel foams with self-tuning moisture balance as chronic wound dressings.

A major challenge in chronic wound treatment is maintaining an appropriate wound moisture balance throughout the healing process. Wound dehydration hinders wound healing due to impeded molecule transport and cell migration with associated tissue necrosis. In contrast, wounds that produce excess fluid contain high levels of reactive oxygen species and matrix metalloproteases that impede cell recruitment, extracellular matrix reconstruction, and angiogenesis. Dressings are currently selected based on the relative amount of wound exudate with no universal dressing available that can maintain appropriate wound moisture balance to enhance healing. This work aimed to develop a high porosity poly(ethylene glycol) diacrylate hydrogel foam that can both rapidly remove exudate and provide self-tuning moisture control to prevent wound dehydration. A custom foaming device was used to vary hydrogel foam porosity from 25% to 75% by adjusting the initial air-to-solution volume ratio. Hydrogel foams demonstrated substantial improvements in water uptake volume and rate as compared to bulk hydrogels while maintaining similar hydration benefits with slow dehydration rates. The hydrogel foam with the highest porosity (~75%) demonstrated the greatest water uptake and rate, which outperformed commercial dressing products, Curafoam® and Silvercel®, in water absorption, moisture retention, and exudate management. Investigation of the water vapor transmission rates of each dressing at varied hydration levels was characterized and demonstrated the dynamic moisture-controlling capability of the hydrogel foam dressing. Overall, the self-tuning moisture control of this hydrogel foam dressing holds great promise to improve healing outcomes for both dry and exudative chronic wounds.

Study on the Adaptability of Jurassic Nitrogen Foam Cone Pressing

Aiming at the problems of bottom water coning and oil well flooding caused by the large impact of the early production strength of the Jurassic bottom water direct contact well in the Seventh Oil Production Plant. Carry out research on nitrogen foam control bottom water coning technology, mainly including: ①laboratory test to optimize foam system suitable for Jurassic system of No. 7 Oil Production Plant, determine injection concentration and optimal gas-liquid ratio; ②The nitrogen foam injection timing and shut in time were optimized by numerical simulation method; ③Summarize the field tests that have been carried out, and determine the optimal combination of parameters suitable for the Jurassic nitrogen foam pressure cone of No. 7 Oil Production Plant.

Development of Water Repellent, Non-Friable Tannin-Furanic-Fatty Acids Biofoams.

Tannin-furanic foams were prepared with a good yield using the addition of relatively small proportions of a polyflavonoid tannin extract esterified with either palmitic acid, oleic acid, or lauric acid by its reaction with palmitoyl chloride, oleyl chloride, or lauryl chloride. FTIR analysis allowed us to ascertain the esterification of the tannin, and MALDI-TOF analysis allowed us to identify a number of multi-esterified flavonoid oligomers as well as some linked to residual carbohydrates related to the equally esterified tannin. These foams presented a markedly decreased surface friability or no friability at all, and at densities lower than the standard foam they were compared to. Equally, these experimental foams presented a much-improved water repellence, as indicated by their initial wetting angle, its small variation over time, and its stabilization at a high wetting angle value, while the wetting angle of the standard foam control went to zero very rapidly. This conclusion was supported by the calculation of the total surface energy of their surfaces as well as of their dispersive and polar components.