Fiber Foam Research Articles

Liquid absorbent bamboo fiber foams: Towards 100% ligno-cellulosic menstrual absorbent pads

Traditional menstrual absorbent pads typically combine cellulose fiber fluff pulp with non-biodegradable, petroleum-based superabsorbent polymers (SAPs). To eliminate the need for SAPs, this study explores foaming as a method to create a highly porous lignocellulosic fiber network capable of storing large amounts of fluid. Bamboo fibers were chosen due to their high lignin content, which is expected to help maintain the structural integrity of the porous network during liquid absorption and preventing collapse compared to 100% cellulose fibers. The bamboo fiber foams demonstrated remarkable porosity and superior absorbency compared to commercial pads, but they exhibited lower water retention when subjected to compression. Refining the fibers and incorporating microfibrillated cellulose offer promising opportunities to enhance water retention.

Characterization, modeling and prediction of foam-formed softwood fiber sound absorption

The transition towards building materials with low or negative carbon-dioxide footprint is a pressing topic in nowadays society. Materials for thermal and acoustic insulation are among those attracting a growing number of research publications. Commonly used materials in the building sector are mostly mineral wools which demand huge amounts of energy during production by melting sand or stone. Cellulose-based materials are a promising substitute for the current market leaders. These materials are able to reach negative carbon footprints due to low embodied energy and their ability to store carbon dioxide in buildings for decades. Predicting the sound absorption behavior prior to manufacturing can further improve their usability. This study delves into the prediction and characterization of wood-based pulp fiber foams and their acoustic properties. By comparing analytical models, semi-phenomenological models and experimental measurements the prediction of sound absorption based on fiber diameter and bulk density is evaluated. The findings reveal that refining a recent analytical model for natural fibers through parameter fitting to non-acoustic parameters yields improved accuracy in predicting sound absorption curves. While the accuracy declines towards higher densities, this work lays the groundwork to create environmentally sustainable sound absorbers with carefully tailored sound absorption properties.

A simple method for preparing Sb2S3/short-cut carbon fiber foam for the electrocatalytic degradation of dyes

The unstarched short-cut carbon fiber (SCF) foam modified with Sb2S3 nanoparticles (Sb2S3/SCF foam) was synthesized by melamine foam as a template to apply in electro-degradation of methyl orange (MO) and a mixture of dyes. This process takes full advantage of the self-supported 3D SCF foam's mechanical stability and electrical conductivity while preventing the aggregation of unstarched SCF and Sb2S3 nanoparticles. The in-situ deposition and good dispersion of Sb2S3 nanoparticles expose catalytic active sites synergy with stable free-standing 3D SCF foam resulting in efficient degradation capability. The morphology, composition, structure, and hydrophilicity of Sb2S3/SCF foam were analyzed using SEM, EDS, XPS, XRD, Raman, PL, BET and contact angle tests. The Sb2S3/SCF foam is highly effective for degrading MO, with a degradation rate of 97.92 % achieved in just 4 hours at 2.4 V (vs. SCE). Additionally, it could simultaneously degrade mixed dyes including methyl orange (MO), crystal violet (CV), and methylene blue (MB) within 5 hours, achieving complete fade. Furthermore, the Sb2S3/SCF foam also possesses desirable features for large-scale practical applications and recycling in dye degradation.

Foaming and cross-linking of cellulose fibers using phytic acid

Bio-based compounds have become the focus in the development of next-generation materials. The polyphosphated structure and availability of phytic acid has sparked an interest to understand its properties and apply it to making fire-retardant fabrics. However, its degradative effect on natural fibers sets limitations to its potential uses. In this study, we unveiled a new dimension to explore with phytic acid: cellulose fiber foams. Phytic acid enabled synergistic foaming with carboxymethyl cellulose albeit causing issues in long-term wet foam stability. Adding cellulose fibers to this mixture and drying at 160 °C produced solid foams with increased compressive strength and stiffness; comparable to foams cross-linked with the commonly used citric acid. The reduced contact area in low-density fiber networks allowed the cross-linking between phytic acid and the fiber network to mitigate structural weakening due to fiber degradation. Imaging also revealed the formation of a film encompassing fiber bonds; attributed to the strong interaction between phytic acid and carboxymethyl cellulose. Furthermore, phytic acid imparted self-extinguishing fire-retardant properties to the cellulose fiber foams measured using thermogravimetric analysis and cone calorimetry. This work showcases a simple new application for phytic acid without the use of catalysts or solvents. It serves to encourage further development of green practices to continuously challenge the industrial landscape.

Betulin Enables Multifunctional Cellulose-Based Insulative Foams with Low Environmental Impacts.

The significance of synthetic foams as insulative materials stems from their mechanical and water resistance as well as their cost-effectiveness. Broadly, the design of building envelopes should also consider fire and mold resistance and the impacts on the environment (end of life and compostability). This study addresses these issues considering the ever-increasing demand for sustainable sources to develop highly porous insulative materials. We introduce a versatile strategy based on wet-foam laying of cellulosic fibers that leads to hierarchical structures whose performance is tailored by the surface incorporation of betulin (BT), a bioactive molecule extracted from tree bark, combined with poly(dimethylsiloxane) (PDMS) after installation of urethane linkages. As such, we introduce an eco-friendly alternative to traditional polyurethane foams with competitive mechanical and thermal insulation performance. The modification of the fiber foams at low BT loading simultaneously endows superhydrophobicity (water contact angle >150°), fire retardancy (self-extinguish within 10 s), microbial resistance, and durability (no degradation in soil conditions after 3 months). BT plays a critical role as an antimicrobial and hydrophobic agent that synergizes with PDMS to achieve fire resistance. The life cycle assessment of the BT-modified foams reveals a significant reduction in greenhouse gas emission and human toxicity compared with rigid polyurethane foams by 96 and 92%, respectively. Overall, the valorization of the bark-derived BT is demonstrated by considering the scalability and cost-effectiveness of solid foams designed to substitute petroleum-derived counterparts.

Construction of PPS based carbon fiber photothermal foam for crude oil absorption and seawater desalination

Efficient and clean solar energy conversion through photothermal materials has garnered significant attention, finding applications across energy, environmental protection, and healthcare sectors. This project focused on developing waste PPS-based carbon fiber (PCF) foam, emphasizing the high-value utilization of waste fibers in solar photothermal oil-absorption and photothermal evaporation applications. With exceptional light-absorption capabilities exceeding 97 %, the PCF@PDMS foam demonstrated superior photothermal conversion efficiency alongside impressive mechanical properties, facilitating effective absorption of highly viscous crude oil. Through PVA/CNF hydrophilic modification, internal water supply channels were integrated into the mPCF@PDMS foam, optimizing the evaporation surface area by retaining hydrophobic regions. This design not only enhanced thermal insulation but also significantly increased the evaporation rate to 2.00 kg·m−2·h−1 with an efficiency of 89.89 % under 1.0 sun irradiation. The presence of hydrophobic regions endowed the evaporator with self-floating ability, enhancing its practicality. During simulations of seawater desalination, the prepared evaporator exhibited remarkable salt crystallization resistance attributed to the strong water supply capacity and Marangoni effect induced during saltwater evaporation, facilitating salt diffusion and water evaporation. Overall, the foams developed in this project hold substantial application potential in the realm of photothermal technology.

Effect of Starch and Paperboard Reinforcing Structures on Insulative Fiber Foam Composites.

Single-use plastic foams are used extensively as interior packaging to insulate and protect items during shipment but have come under increasing scrutiny due to the volume sent to landfills and their negative impact on the environment. Insulative compression molded cellulose fiber foams could be a viable alternative, but they do not have the mechanical strength of plastic foams. To address this issue, a novel approach was used that combined the insulative properties of cellulose fiber foams, a binder (starch), and three different reinforcing paperboard elements (angular, cylindrical, and grid) to make low-density foam composites with excellent mechanical strength. Compression molded foams and composites had a consistent thickness and a smooth, flat finish. Respirometry tests showed the fiber foams mineralized in the range of 37 to 49% over a 46 d testing period. All of the samples had relatively low density (Dd) and thermal conductivity (TC). The Dd of samples ranged from 33.1 to 64.9 kg/m3, and TC ranged from 0.039 to 0.049 W/mk. The addition of starch to the fiber foam (FF+S) and composites not only increased Dd, drying time (Td), and TC by an average of 18%, 55%, and 5.5%, respectively, but also dramatically increased the mechanical strength. The FF+S foam and paperboard composites had 240% and 350% higher average flexural strength (σfM) and modulus (Ef), respectively, than the FF-S composites. The FF-S grid composite and all the FF+S foam and composite samples had equal or higher σfM than EPS foam. Additionally, FF+S foam and paperboard composites had 187% and 354% higher average compression strength (CS) and modulus (Ec), respectively, than the FF-S foam and composites. All the paperboard composites for both FF+S and FF-S samples had comparable or higher CS, but only the FF+S cylinder and grid samples had greater toughness (Ωc) than EPS foam. Fiber foams and foam composites are compatible with existing paper recycling streams and show promise as a biodegradable, insulative alternative to EPS foam internal packaging.

Mechanically robust, thermal insulating sustainable foams fully derived from bamboo fibers through high temperature drying

The development of lignocellulosic foams has been gaining momentum due to their sustainability and biodegradability. However, lignocellulosic foams often have low preparation efficiency and poor mechanical properties, especially compression performance. Here, we constructed mechanically robust and thermal insulating cellulosic foams through high-temperature drying, in which all bamboo-sourced lignin-containing pulp fibers (LPF) and steam explosion fibers (SEF) were chosen as a skeleton and high solid fibrillated cellulose (HSFC) as a binder. This study aimed to investigate the effects of the characteristics of bamboo fibers and the HSFC addition on the formation, and mechanical- and thermal insulation performances of the resulting foams. The HSFC incorporation endowed the foams with excellent mechanical performance, the stress at 10 % strain and compressive modulus were 0.29 MPa and 4.4 MPa, respectively, which were 10-fold and 44-fold compared to LPF foam without HSFC. The LPF/HSFC possessed excellent energy absorption capacity (170 kJ/m3 under 40 % strain) as well as good thermal insulating performance (0.054 W/(m·K)). The LPF/HSFC foam with a much more homogeneous cellular structure outperformed the SEF/HSFC foam. This work suggests that the developed bamboo fiber foams hold promise for use in protective packaging and thermal insulation applications.

Bioactive Fiber Foam Films from Cellulose and Willow Bark Extract with Improved Water Tolerance.

Cellulose-based materials are gaining increasing attention in the packaging industry as sustainable packaging material alternatives. Lignocellulosic polymers with high quantities of surface hydroxyls are inherently hydrophilic and hygroscopic, making them moisture-sensitive, which has been retarding the utilization of cellulosic materials in applications requiring high moisture resistance. Herein, we produced lightweight all-cellulose fiber foam films with improved water tolerance. The fiber foams were modified with willow bark extract (WBE) and alkyl ketene dimer (AKD). AKD improved the water stability, while the addition of WBE was found to improve the dry strength of the fiber foam films and bring additional functionalities, that is, antioxidant and ultraviolet protection properties, to the material. Additionally, WBE and AKD showed a synergistic effect in improving the hydrophobicity and water tolerance of the fiber foam films. Nuclear magnetic resonance (NMR) spectroscopy indicated that the interactions among WBE, cellulose, and AKD were physical, with no formation of covalent bonds. The findings of this study broaden the possibilities to utilize cellulose-based materials in high-value active packaging applications, for instance, for pharmaceutical and healthcare products or as water-resistant coatings for textiles, besides bulk packaging materials.

Starch-fibers composites, a study of all-polysaccharide foams from microwave foaming to biodegradation

Sustainable composite foams based on rice starch and cellulosic long fibers were successfully fabricated using microwave irradiation. They were presented as a promising method to recycle some of the textile industry waste. A deep study of the processability and functionality of the composites revealed the performance improvement of starch with the addition of long cellulosic fibers, especially with 6 wt% of Arbocel®, in terms of foamability, water, and mechanical resistance features. Moreover, sodium bicarbonate, which acted as a blowing and pulping agent, led to a lower density and better fiber distribution that resulted in an improvement of the foams' functionalities. The range of the study is new in the domain of long fiber foam composites in terms of the foaming capability, and mechanical, thermal, and water resistance properties. Furthermore, all foams showed excellent biodegradability properties against a fungus commonly found in the environment; for example, values around 60 % weight loss after 33 days. Finally, the assessment of the CO2 emission during the process underlines the environmental benefits of the method employed.

Plant fiber foam reinforced with distiller's grains and its static cushioning properties

The non-degradability of plastic foam and limited petroleum resources have caused great damage to the ecological environment of the earth. Here a bio-based foam was fabricated to explore its potential as cushioning packaging materials. Plant fiber foam (PFF) was prepared by foaming via mechanical stirring and oven drying. Sodium alginate (SA) and distiller's grains (DG) were introduced into plant fiber foam as cross-linking agent and filler respectively to enhance fiber bonding and improve the mechanical properties of PFF. Static cushioning properties of PFF were investigated. In addition, the static compression constitutive model of PFF was established and the results showed the model could be used to predict the stress-strain curve of PFF under static compression.

Exploring Foam Drainage in Fiber-Foam: A Review

The foam drainage is extremely important in many situations where fiber foams are used. Enhancing wet foam stability requires a complete understanding of the mechanisms and factors affecting wet foam drainage. Investigation of the drainage behavior of fiber foams has been studied in this review. The mechanics behind fiber foam drainage are discussed in detail, along with the influence of surfactant concentration, fiber consistency, and other variables. It also investigated adding additives, such as chemi-thermo-mechanical pulp (CTMP), affects foam drainage. Highlighting the most recent developments in experimental and theoretical methods for describing and forecasting foam drainage behavior are presented. This review acts as a reference to offer useful understanding of the essential factors of foam drainage in fiber foams solution.

Fe/N Codoped Paper Carbon Fiber Foam Promoted Extracellular Electron Transfer for a High-Performance Microbial Fuel Cell

Fe/N Codoped Paper Carbon Fiber Foam Promoted Extracellular Electron Transfer for a High-Performance Microbial Fuel Cell

Real-microcellular poly(ether-block-amide)/carbon fiber foams with improved mechanical property and surface quality for high-performance electromagnetic interference shielding applications

Challenges remain in large-scale and successive preparation of porous polymer composite component, which limits its practical applications for high-performance electromagnetic interference (EMI) shielding. Herein, a scalable and efficient method based on mold-opening foam injection molding was developed to fabricate carbon fiber (CF) reinforced polymer composite foams for EMI shielding applications. Thanks to the novel foaming process and heterogeneous nucleation effect of CF, real microcellular poly(ether-block-amide) (PEBA)/CF composite foams with an average cell size of 6.6 μm and a cell density of up to 109 cells/cm3 were achieved. Due to the significantly refined cellular morphology, the PEBA/CF composite foams exhibit superior EMI shielding performance over the unfoamed composites which was characterized by absorption-dominated shielding characteristics and significantly enhanced EMI shielding effectiveness. Furthermore, compared with the unfoamed case, the foamed PEBA/CF composites with refined cellular morphology shows greatly improved cold toughness and duality, and the tensile strain at break and specific tensile toughness are increased by 88.6% and 109.1%, respectively. Moreover, real-microcellular PEBA/CF composite foams have remarkably enhanced surface quality than those fabricated by regular foam injection molding process, and the surface roughness can be maximumly increased by 91.6%. Thus, this study provides a promising strategy for producing lightweight and strong components for high-performance EMI shielding applications.

Novel filter material by glass fiber foam laying for nonwoven fabrics

The needle punched nonwoven fabrics are widely used as the flue gas filter materials while continuous efforts have been made to improve the filtration efficiency in order to meet the low emission requirement. In this study, filter materials with high filtration efficiency were developed via glass fiber foam laying and PTFE (polytetrafluoroethylene) emulsion coating process. Influences of surfactant type, fiber diameter and fiber content on the foam-ability and foam stability of glass fibers were analyzed. The resulting filter materials, obtained here for the first time with glass fiber foam laden and PTFE emulsion coated needle punched nonwoven fabrics, were characterized for morphology, pore size, air permeability, wear resistance and filtration properties. The results were compared against structures obtained from needle punched nonwoven fabrics before and PTFE emulsion coating. Remarkably, compared to untreated and PTFE emulsion coated needle punched nonwoven fabrics, the glass fiber foam laden and PTFE emulsion coated fabrics displayed higher filtration efficiency and lower outlet particle concentration. Overall, glass fiber foam laying is found to be effective to improve the filtration performance of needle punched nonwoven fabrics and is promising to be commercialized after optimizing the foam composition and PTFE emulsion coating process.

Compressible polyaniline-coated sodium alginate-cattail fiber foam for efficient and salt-resistant solar steam generation

Solar steam generation has attracted widespread attention because of its ability to produce clean water through desalination and wastewater treatment without conventional energy consumption. In this work, a polyaniline (PANI)-coated sodium alginate (SA)/cattail fiber (CF) foam for photothermal evaporator is prepared via directional freezing and oxidative polymerization. The SA/CF foam displays desirable water pumping capability because of the lamellar sandwich structure interconnected by porous networks. More importantly, the directional porous network architecture ameliorates the mechanical and salt-resistant performances of the SA/CF foam. The as-prepared PANI@SA/CF foam shows inferior heat conductivity of 0.047 W m−1 K−1 and outstanding light absorption over 96% in solar window. A vapor evaporation rate of 2.04 kg m−2 h−1 under 1 sun illumination is achieved for the PANI@SA/CF evaporator. Furthermore, the PANI@SA/CF foam could be employed in solar-driven freshwater generation from seawater and wastewater with high ion and dye removal rates. The combination of water evaporation and cleaning capabilities of the PANI@SA/CF foam as photothermal materials provide a framework for the exploration of next-generation evaporators in seawater desalination and wastewater treatment applications.

Improved Fly Ash Based Structural Foam Concrete with Polypropylene Fiber

The direction of construction science that is associated with the development of the theory and practice of creating a new generation of foam concrete is particularly interesting and relevant. The development of improved structural foam concrete using polypropylene fiber and industrial waste, namely fly ash (FA), is prompted by the existing environmental threat posed by FA; this threat is a result of the operation of the fuel energy industry, as well as the possibility of using foam concrete not only as thermal insulation, but as the main material for load-bearing structures that have a certain level of responsibility. The aim of this work was to create and optimize the recipe technological parameters to produce non-autoclaved fiber foam concrete (FFC) using FA as a component. The study used standardized methods for assessing the properties of FFC, and the method of optical microscopy to analyze the structural characteristics of the material. It has been revealed that the replacement of cement with FA in an amount of 10% to 40% helps to reduce the dry density (DD) of FFC. The lowest DD was recorded for samples with 40% FA. The best results for the compressive strength (CS) and flexural strength (FS) were recorded for FFC samples with 10% FA instead of cement. The increase in CS was 12%, and the increase in FS was 23%. The best thermal insulation properties of FFC, and in terms of resistance to freezing and thawing, were recorded in samples with a 10% replacement of cement with FA. The maximum decrease in thermal conductivity was 14%.

Формирование структуры фибропенобетона на макроуровне

The article presents a method for designing the composition of fiber foam concrete taking into account the determination of the optimal content of reinforcing fibers to achieve the required properties. There have been carried out experimental studies on the formation of the macrostructure of fiber foam concrete with dense packing of the material of inter-pore partitions with fiber reinforcement, which provides an increase in strength at a given average density.

Optimization of the composition of fiber foam concrete with polypropylene fiber Fox Polfiber M12 produced by basf company

The results of experimental studies on optimizing the composition of non-autoclaved fiber foam concrete with polypropylene fiber Fox Polfiber M12 produced by BASF (Germany) and on determining its properties are presented in the article. A pattern was established for a decrease in shrinkage strain in non-autoclaved fiber foam concrete with an increase in the content of polypropylene fiber by weight and a reduction in cement consumption. At that, the least shrinkage strains in samples of fiber foam concrete were observed at a minimum content of mineral filler –micro-silica.

Static Compressive Properties of Polypropylene Fiber Foam Concrete with Concave Hexagonal Unit Cell

For the purpose of studying the influence of fiber on the negative Poisson’s ratio effect of foam concrete, a concave hexagonal unit cell structure of polypropylene fiber foam concrete was proposed. The effects of different fiber volume contents on the structural mechanical parameters, Poisson’s ratio, and energy absorption capacity of the unit cells were studied by static compression of concave hexagonal unit cells and cube specimens. The results show that the compressive strength of foam concrete is reduced by adding polypropylene fiber, and the peak stress of concave hexagonal unit cells decreases less rapidly than that of cube specimens. The proper amount of polypropylene fiber can enhance the deformation ability of the unit cells in foam concrete, and the Poisson’s ratio of the unit cells in foam concrete with 1.5% fiber content is the lowest. In the process of failure of concave hexagonal unit cells, the failure phenomenon is mainly concentrated on the concave surfaces on both sides, and the cracks are distributed in the form of “upper left and lower right” or “lower left and upper right”. When the content of polypropylene fiber is 0.5%, the total energy absorbed by the concave hexagonal cells in the compression deformation process increases by 12.98%.