Chitosan Foam Research Articles

Facile synthesis and biomimetic amine-functionalization of chitosan foam for CO2 capture

A high-performance biomass-based adsorption materials could be the promising trend for CO2 capture and storage technology. However, the direct application of biomass-based porous materials as a CO2 adsorbent with enhanced performance is an emerging issue. Herein, a facile synthesis and a biomimetic strategy were combined to prepare amine-functionalized chitosan foam for CO2 capture, and then a porous biomass is achieved for the application on the environment protection field. Firstly, the chitosan foam was synthesized by the emulsion-templating method at room temperature. Depended on stabilizing n-octane in the chitosan hydrogel with Span 80, a tunable three-dimensional network porous structure was obtained. Subsequently, co-deposition with dopamine (DA) and polyethyleneimine (PEI) was applied to load abundant amine content on the surface of chitosan foam and thereby improving CO2 adsorption capacity. Finally, the as-prepared amine-functionalized chitosan foam exhibited the impressive adsorption capacity of 3.59 mmol/g at 333 K and atmospheric pressure, and the better adsorption selectivity and stability. The results extend the preparation approach of biomass porous materials, and also its application in CO2 adsorption technology.

Adsorption of sulfamethoxazole and ciprofloxacin on chitosan foam: Isotherms modeling and binding mechanisms

The paper investigates the adsorption of two pharmaceutical compounds (PCs) from polluted water, namely sulfamethoxazole (STZ) and ciprofloxacin (CRA), onto a new adsorbent formed by dispersion of chitosan on polyurethane (PU/C). Adsorption isotherms were determined on the investigated adsorbent as a function of temperature, in the range 298–328 K. For each temperature, PU/C showed higher affinity toward STZ with a maximum adsorption capacity at the maximum investigated temperature. A double-layer model was adopted for the interpretation of the entire adsorption data set. The number of adsorbate molecules bound per active site allowed for determining that an aggregation process occurs upon adsorption. The retrieved values for the CRA- PU/C system are 1.37, 1.61, 1.68, and 0.606 at 298, 308, 318, and 328 K, respectively, while for the STZ- PU/C system, the corresponding values are 0.76, 1.07, 1.23 and 1.36 at T = 298, 308, 318 and 328 K respectively. Finally, the values of adsorption energy define the phenomenon under investigation as a physisorption.

A photocrosslinkable and hemostatic bilayer wound dressing based on gelatin methacrylate hydrogel and polyvinyl alcohol foam for skin regeneration

The enormous potential of multifunctional bilayer wound dressings in various medical interventions for wound healing has led to decades of exploration into this field of medicine. However, it is usually difficult to synthesize a single hydrogel with all the required capabilities simultaneously. This paper proposes a bilayer model with an outer layer intended for hydrogel wound treatment. By adding gelatin methacrylate (GelMA) and tannic acid (TA) to the hydrogel composition and using polyvinyl alcohol-carboxymethyl chitosan (PVA-CMCs) foam layer as supports, a photocrosslinkable hydrogel with an optimal formulation was created. The hydrogels were then examined using a range of analytical procedures, including mechanical testing, rheology, chemical characterization, and in vitro and in vivo tests. The resulting bilayer wound dressing has many desirable properties, namely uniform adhesion and quick crosslinking by UV light. When used against Gram-positive and Gram-negative bacterial strains, bilayer wound dressings demonstrated broad antibacterial efficacy. In bilayer wound dressings with GelMA and TA, better wound healing was observed. Those without these elements showed less effectiveness in healing wounds. Additionally, encouraging collagen production and reducing wound infection has a major therapeutic impact on wounds. The results of this study could have a significant impact on the development of better-performing wound dressings.

Chitosan-based foam composites for hexavalent chromium remediation: Effect of microcellulose and crosslinking agent content

Potentially toxic metal ions, such as hexavalent chromium (Cr6+), present in water concern the population's health due to their persistence, bioaccumulation potential, and high toxicity. Highly porous materials based on polysaccharides are promising technologies for metal removal due to their high surface area, biodegradability, and low toxicity. This study evaluated the effect of concentrations of microcellulose (0.5, 1, and 1.5 %) and glutaraldehyde (1, 2, and 3 %) in the adsorption capacity and mechanical properties of chitosan foams. The developed foams exhibited a three-dimensional structure with interconnected pores. Compared to foams without microcellulose, adding 1.5 % microcellulose increased up to 180 % in maximum stress supported by the foams and up to 135 % in Young's modulus. However, Cr6+ sorption capacity decreased with increasing microcellulose and crosslinking agent content due to the occupation of amino groups. Still, the foams exhibited a highly favorable sorption behavior, and the Sips isotherm model provided the best fit to the experimental data. The maximum sorption capacity reached approximately 1.4 mmol·g−1 at pH 4.0 and 25 °C. The foam structural integrity, enhanced mechanical properties, and efficient sorption capacity make them viable alternatives for environmentally friendly and cost-effective treatment of water contaminated with Cr6+ ions.

Box–Behnken experimental design for optimization of chitosan foam materials reinforced with cellulose and zeolite

AbstractFoam materials produced from biopolymers stand out as a more environmentally friendly insulation material solution. This study presents a comprehensive investigation into the development and optimization of chitosan‐based foam materials using a Box–Behnken design. The foams were engineered using varying proportions of chitosan (0.5–3%), cellulose (0.5–3%), and zeolite (0.5–3%), targeting their application as thermal insulators. The physical and thermal properties of the foams that were produced were affected by the type and ratios of components, with density and thermal conductivity ranging from 0.0853 to 0.1915 g cm−3 and 0.0324 to 0.0921 W mK−1, respectively. Higher chitosan content improved insulation properties and mechanical strength whereas zeolite increments increased density and thermal conductivity. Using statistical analysis through the Box–Behnken design, we optimized the foam formulations, achieving minimum thermal conductivity and maximum compression strength at an averaged density, suggesting a strong potential for environmental sustainability applications. The recommended optimal chitosan:cellulose:zeolite composition ratio of 3:3:0.88 provides a valuable insight for tailored foam material formulation. This study shows the relationships between the composition of a composite material and its resultant properties, optimizing its preparation for industrial applicability in an environmentally conscious way within the context of insulation and construction. This investigation contributes to the field of material science by highlighting the versatility and potential of biopolymers but also aligns with the increasing need for green building materials.

One-step synthesis of phospho-rich, silica-enhanced chitosan aerogel for the efficient adsorption of uranium(VI)

In this study, an amorphous silica reinforced, phosphoric-crosslinked chitosan foam (P-CTS@SixOy) was prepared. The introduction of amorphous silica not only increased the affinity of the adsorbent for uranium, but also improved the stability of the material. The number of active sites of P-CTS@SixOy was increased by the introduction of phosphate groups. The material exhibited excellent uranium adsorption performance with the removal capacity and efficiency of 850.5 mg g−1 and 98.1 %, respectively. After regenerations, the morphology of P-CTS@SixOy still maintained, and the uranium adsorption efficiency remained above 90 %, manifesting the excellent cycle performance of P-CTS@SixOy. In the dynamic adsorption experiment, P-CTS@SixOy successfully concentrated the volume of uranium-containing solution, and exhibited excellent uranium adsorption performance. The analysis of kinetics, isotherms, and thermodynamics manifested that the uranium adsorption behavior of P-CTS@SixOy was a spontaneous, endothermic, monolayer chemical adsorption process. X-ray photoelectron spectroscopy, Scanning Electron Microscope, and Fourier Transform Infrared Spectrometer were used to characterized the P-CTS@SixOy before and after adsorption, which demonstrated that the main interaction mechanism between uranium and P-CTS@SixOy was the complexation. These studies indicated the huge application prospect of P-CTS@SixOy in the treatment of large-scale uranium-containing wastewater.

Cellulose Nanocrystal Embedded Composite Foam and Its Carbonization for Energy Application.

In this study, we fabricated a cellulose nanocrystal (CNC)-embedded aerogel-like chitosan foam and carbonized the 3D foam for electrical energy harvesting. The nanocrystal-supported cellulose foam can demonstrate a high surface area and porosity, homogeneous size ranging from various microscales, and a high quality of absorbing external additives. In order to prepare CNC, microcrystalline cellulose (MCC) was chemically treated with sulfuric acid. The CNC incorporates into chitosan, enhancing mechanical properties, crystallization, and generation of the aerogel-like porous structure. The weight percentage of the CNC was 2 wt% in the chitosan composite. The CNC/chitosan foam is produced using the freeze-drying method, and the CNC-embedded CNC/chitosan foam has been carbonized. We found that the degree of crystallization of carbon structure increased, including the CNCs. Both CNC and chitosan are degradable materials when CNC includes chitosan, which can form a high surface area with some typical surface-related morphology. The electrical cyclic voltammetric result shows that the vertical composite specimen had superior electrochemical properties compared to the horizontal composite specimen. In addition, the BET measurement indicated that the CNC/chitosan foam possessed a high porosity, especially mesopores with layer structures. At the same time, the carbonized CNC led to a significant increase in the portion of micropore.

Scalable fabrication of biodegradable, thermally insulating, fire-proof bioplastic foams via rapid magnetic force assisted squeezing and ambient drying

Foam materials are in great demand in modern society, which are widely used in shock absorption, packaging, heat preservation, and building insulation. However, the severe contamination of non-biodegradable plastic foam waste accumulated in the environment has increased the demand and interest in the development of degradable and multifunctional bio-sourced materials. Manufacturing of biomass foam, however, often requires long-term operation of specialized equipment under extreme conditions, making it not as environmentally friendly as claimed. Here we present an energy-efficient freeze-drying-free approach for bioplastic foam production from marine biomass waste via freeze-thawing of shear-flow-induced micro-/nano-fibrous hydrogels and rapid magnetic force-assisted squeezing and ambient drying, which differs substantially from existing inefficient and energy-consuming drying processes. The magnetic force-assisted pre-dehydration strategy prevents the collapse of the 3D network structure under capillary action during solvent evaporation, enabling a low density of 25.5–37.5 mg cm−3 and ultralow shrinkage of 9.3%-12.2%. These ambient-dried chitosan foams exhibit a high compressive modulus (366–732 kPa, supporting ∼ 4600 times its own weight), favorable thermal insulation performance (0.038 W m−1 K−1), competitive thermal stability, and fire resistance (smokeless combustion and self-extinguishing). Moreover, this bioplastic foam has been demonstrated to be recyclable and biodegradable with a substantially reduced environmental impact, as evidenced by life-cycle assessment analysis, representing a promising alternative to petroleum-based plastic foam.

Dialdehyde cellulose nanocrystal cross-linked chitosan foam with high adsorption capacity for removal of acid red 134

Dialdehyde cellulose nanocrystal cross-linked chitosan foam with high adsorption capacity for removal of acid red 134

Silk composite interfacial layer eliminates rebleeding with chitosan-based hemostats

Chitosan foams are among the approved hemostats for pre-hospital hemorrhagic control but suffer from drawbacks related to mucoadhesiveness and rebleeding. Herein, we have developed a designer bilayered hemostatic foam consisting of a bioactive layer composed of silica particles (≈300 nm) and silk fibroin to serve as the tissue interfacing component on a chitosan foam. The foam composition was optimized based on the in vitro clotting behavior and cytocompatibility of individual components. In vivo analysis in a rat model demonstrated that the developed hemostat could achieve rapid clotting (31 ± 4 s), similar to a chitosan-based hemostat, but the former had significantly lower blood loss. Notably, removal of the bilayered hemostat prevented rebleeding, unlike the chitosan foam, which was associated with markedly higher incidences of rebleeding (50 %) and left behind material residue. Thus, the designer bilayered foam presented here is a potent inducer of blood clotting whilst affording easy removal with minimal rebleeding.

Activated carbon and cellulose-reinforced biodegradable chitosan foams

Chitosan foams with promising mechanical properties, heat-insulating ability, and flame retardancy were produced through oven drying. The chitosan foams were reinforced with cellulose, boric acid, and different ratios of activated carbon. The foams showed desirable low density (80.2 to 109.8 kg/m3) and compression properties. The compression resistance and compression modulus of foams ranged between 53.6 and 98.5 KPa and 214 to 394 KPa, respectively. Thermal conductivity tests revealed that the foams endowed low thermal conductivity values (0.035 to 0.051 W/mK). The limiting oxygen index (LOI) of the foams was as high as 32.9% for activated carbon (20 g/L). The activated carbon reinforcement produced higher thermal properties and decreased the mass loss 48.1% at 600 °C. The produced foams exhibited good biodegradability (39% degradation in 15 days). The overall test results showed that the chitosan foams can be utilized as a promising environmentally friendly material in thermal insulation fields.

Chitosan foam reinforced by SiC whisker for building insulation with high mechanical strength and vapor permeability

Chitosan foam reinforced by SiC whisker for building insulation with high mechanical strength and vapor permeability

Cellulose–Chitosan Biodegradable Materials for Insulating Applications

Bio-based lightweight porous materials have attracted attention due to their unique properties and have become an interesting alternative to petroleum-based foams such as expanded polystyrene (EPS) and polyurethane foams. In this work, biodegradable cellulose pulp–chitosan foams were obtained through a low-cost, simple, and scalable method. A full factorial design was carried out to study the effects of three experimental factors (chitosan content, foaming agent concentration, and foaming time) on apparent density and mechanical properties. The prepared foams displayed low apparent densities (0.06–0.12 g/cm3), good mechanical performance (elastic modulus: 0.18–1.20 MPa, compressive strength: 0.02–0.11 MPa), excellent thermal insulation properties (thermal conductivities: 0.03–0.04 W/mK), and high biodegradation rates. The increase of chitosan content improved the water resistance and mechanical strength. Finally, these materials could be suitable for several applications in which thermal insulation, mechanical resistance, and water stability are crucial, including packaging and construction, as an alternative to traditional nonbiodegradable materials.

Ag-Contained Superabsorbent Curdlan-Chitosan Foams for Healing Wounds in a Type-2 Diabetic Mice Model.

This study focused on the synthesis and characterization of pure curdlan–chitosan foams (CUR/CS), as well as foams containing Ag nanoparticles (CUR/CS/Ag), and their effect on the skin repair of diabetic mice (II type). The layer of antibacterial superabsorbent foam provides good oxygenation, prevents bacterial infection, and absorbs exudate, forming a soft gel (moist environment). These foams were prepared from a mixture of hydrolyzed curdlan and chitosan by lyophilization. To enhance the antibacterial properties, an AgNO3 solution was added to the curdlan/chitosan mixture during the polymerization and was then reduced by UV irradiation. The membranes were further investigated for their structure and composition using optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy, FT-IR spectroscopy, and XPS analysis and modeling. In vivo tests demonstrated that CUR/CS/Ag significantly boosted the regeneration process compared with pure CUR/CS and the untreated control.

Chemically Functionalized Polysaccharide-Based Chelating Agent for Heavy Metals and Nitrogen Compound Remediation from Contaminated Water

The aim of this research was to develop chemically functionalized polysaccharide-based chelating materials with unique heavy metal and nitrogen compound absorptive properties from cellulose, butane tetracarboxylic acid (BTCA), and chitosan. The BTCA was incorporated onto cellulose through an esterification reaction in the presence of sodium phosphate dibasic dihydrate as catalyst and then cross-linked with chitosan. The effect of BTCA concentration, modification time, and temperature on the carboxylic acid content percentage of modified cellulose was analyzed. Furthermore, modified cellulose was cross-linked with chitosan to produce water-insoluble chelating materials for heavy metals and nitrogen compound remediation from contaminated water. Characterization of the modified cellulose and its water-insoluble chelating foam materials including chemical, structural, heavy metals, and nitrogen compound uptake analyses. The modified cellulose–chitosan foam can absorb up to 8.91–66.45 mg/g arsenic, 6.57–29.1 mg/g mercury, 10–75.6 mg/g lead, 10–45.47 mg/g cadmium, and 6.45–21.2 mg/g selenium when the foam was treated with 100–1000 ppb contaminated water. The heavy metal uptake of modified cellulose–chitosan foam in contaminated water was significantly greater than modified cellulose, cellulose, and commercial metal-chelating agent PuroliteFerrIX A33E. The interesting thing is that only 0.2gram foam material is enough to decrease of 1liter arsenic concentration from 100 to 11 ppb, which meets the EPA standards. However, the modified cellulose–chitosan foam also can absorb about 0.2 g/g ammonium nitrate, 0.14 g/g ammonium chloride, and 0.29 g/g ammonia when it was treated with 0.1% nitrogen compound contaminated water. The modified cellulose and modified cellulose–chitosan foam was characterized with TGA, DSC, FTIR, and SEM, confirming the cross-linking of the materials.

The Bone Regeneration Capacity of BMP-2 + MMP-10 Loaded Scaffolds Depends on the Tissue Status.

Biomaterials-mediated bone formation in osteoporosis (OP) is challenging as it requires tissue growth promotion and adequate mineralization. Based on our previous findings, the development of scaffolds combining bone morphogenetic protein 2 (BMP-2) and matrix metalloproteinase 10 (MMP-10) shows promise for OP management. To test our hypothesis, scaffolds containing BMP-2 + MMP-10 at variable ratios or BMP-2 + Alendronate (ALD) were prepared. Systems were characterized and tested in vitro on healthy and OP mesenchymal stem cells and in vivo bone formation was studied on healthy and OP animals. Therapeutic molecules were efficiently encapsulated into PLGA microspheres and embedded into chitosan foams. The use of PLGA (poly(lactic-co-glycolic acid)) microspheres as therapeutic molecule reservoirs allowed them to achieve an in vitro and in vivo controlled release. A beneficial effect on the alkaline phosphatase activity of non-OP cells was observed for both combinations when compared with BMP-2 alone. This effect was not detected on OP cells where all treatments promoted a similar increase in ALP activity compared with control. The in vivo results indicated a positive effect of the BMP-2 + MMP-10 combination at both of the doses tested on tissue repair for OP mice while it had the opposite effect on non-OP animals. This fact can be explained by the scaffold’s slow-release rate and degradation that could be beneficial for delayed bone regeneration conditions but had the reverse effect on healthy animals. Therefore, the development of adequate scaffolds for bone regeneration requires consideration of the tissue catabolic/anabolic balance to obtain biomaterials with degradation/release behaviors suited for the existing tissue status.

Hemicellulose and starch citrate chitosan foam adsorbents for removal of arsenic and other heavy metals from contaminated water

Arsenic and other heavy metal contaminants in water are a significant global health threat. In this study, low-cost, sulfur-free, sustainable, water-insoluble materials with heavy metal remediation properties were produced from renewable resources such as starch, xylan, citric acid, and chitosan. Synthesized starch citrate-chitosan (SCC) foam and xylan citrate-chitosan (XCC) foam were flexible, porous, and elastic. The foams’ arsenic uptake in water was significantly greater than five different commercial metal remediating agents. The mercury and lead uptakes with the synthesized foams were similar to the performance of a commercial sulfur-based product, SorbaTech 450 (ST450). However, the cadmium and selenium uptakes were comparatively lower. The complexation of arsenic with oxygen and nitrogen of the SCC foam was shown with time-of-flight secondary ion mass spectrometry (TOF-SIMS). The XCC foam was also shown to adsorb potassium iodide (KI) at a similar rate to sodium chloride. This may be used to remediate water contaminated with radioactive materials, such as iodine 131.

Application of Shrimp Waste for the Synthesis of Polyurethane–Chitosan Materials with Potential Use in Sorption of Oil Micro-Spills in Water Treatment

Shrimp waste is a common waste in seafood processing. It is used as part of the fish meal which is added to feed. Bearing in mind the Green Deal and sustainability development, it was proposed to use northern prawn shells to obtain chitosan (Ch), which could then be used for polyurethane (PUR) modification. In ports, oil micro-spills often flow into the waters of gulfs and, consequently, into the sea. Systematic chemical and petroleum water pollution may pose a threat to flora and fauna. In this study, chitosan, which was obtained from shrimp shells, was used to synthesize polyurethane–chitosan foams (PUR+Ch) with different chitosan concentrations. Selected physico-chemical and sorption properties in relation to oil and water of these materials were determined. It was found that the amount of Ch added to the foam affected its morphology, hardness, density, and thermal and sorption properties. PUR foam with a 1.5% weight of Ch was characterized as having the highest water and oil sorption. The advantages of the tested material as an innovative product with potentially significant proecological values were estimated using strengths–weaknesses–opportunities–threats (SWOT) analysis. The conducted preliminary research made it possible to demonstrate the use of these materials in the processes of water treatment with the mentioned micropollutants.

Polysaccharides-modified chitosan as improved and rapid hemostasis foam sponges

Serial hemostatic sponges consisting of polysaccharides-modified chitosan foam sponges were prepared by Schiff base crosslinking reaction between the deacetylated chitosan and oxidized dialdehyde cellulose. Such composite foam sponges were characterized by scanning electron microscopy and Fourier-transform infrared spectroscopy to confirm their morphology and compositions. Then the coagulation process was evaluated in vitro by thrombus elasticity meters. Furthermore, the hemostasis experiments on mouse tail vein and rabbit femoral artery were also performed in vivo. The results strongly indicated that such synergistic cellulose-modified chitosan foam sponges showed comprehensively excellent water-absorbing quality, improved mechanical performance, low hemolysis rates, benign cytotoxicity, good resilience ability after repeated compression, and superior hemostasis capability both in vitro and in vivo. Furthermore, the hemostatic mechanism is via adhering/activating the red blood cell/platelet to form robust blood clots through the endogenous coagulation pathway, which serves as a good candidate for emergency trauma treatment in daily civilian and military hemostasis.

Novel Foam Adsorbents in Dyes and Heavy Metals Removal: A Review

The present review comprises various novel foam adsorbents with unique adsorption performance in process of removal of dyes and heavy metals. Water pollution because of toxic dyes and heavy metals and its ill-effect on the ecosystem is of great concern to researchers, as it affects the living creatures on the planet. Novel foam adsorbents from carbon foam, chitosan foam, metal foam and polymer foam were developed as efficient materials with good chelating ability to adsorb dyes and heavy metal ions. Novel carbon foam adsorbents were reported to have superior adsorption capacity in removal of dyes and heavy metals. This review aims to look at various novel foam adsorbents used in adsorption studies and their potential in dyes and heavy metals removal. This work provides a worthy challenge and the future possibility for designing novel foam materials for various applications.