Cellulose Aerogels Research Articles

Adsorbent based on MOF-5/cellulose aerogel composite for adsorption of organic dyes from wastewater

Industries persistently contribute to environmental pollution by releasing a multitude of harmful substances, including organic dyes, which represent a significant hazard to human health. As a result, the demand for effective adsorbents in wastewater treatment technology is steadily increasing so as to mitigate or eradicate these environmental risks. In response to this challenge, we have developed an advanced composite known as MOF-5/Cellulose aerogel, utilizing the Pampas plant as a natural material in the production of cellulose aerogel. Our investigation focused on analyzing the adsorption and flexibility characteristics of this novel composite for organic dye removal. Additionally, we conducted tests to assess the aerogel’s reusability and determined that its absorption rate remained consistent, with the adsorption capacity of the MOF-5/cellulose aerogel composite only experiencing a marginal 5% reduction. Characterization of the material was conducted through XRD analysis, revealing the cubic structure of MOF aerogel particles under scanning electron microscopy. Our study unequivocally demonstrates the superior adsorption capabilities of the MOF-5/cellulose aerogel composite, particularly evident in its efficient removal of acid blue dye, as evaluated meticulously using UV–Vis spectrophotometric techniques. Notably, our findings revealed an impressive 96% absorption rate for the anionic dye under acidic pH conditions. Furthermore, the synthesized MOF-5/cellulose aerogel composite exhibited Langmuir isotherm behavior and followed pseudo-second-order kinetics during the absorption process. With its remarkable absorption efficiency, MOF-5/cellulose aerogel composites are poised to emerge as leading adsorbents for water purification and various other applications.

In situ growth of HKUST-1 on electrospun polyacrylonitrile nanofibers/regenerated cellulose aerogel for efficient methylene blue adsorption

Dyes, as organic pollutants, are causing increasingly severe environmental problems. Metal-organic frameworks (MOFs) are considered promising dye adsorbents; however, their application is limited due to their powder or solid particle forms and limited reusability. Therefore, this study proposes an innovative approach to develop a novel MOF-based composite aerogel, specifically a HKUST-1/polyacrylonitrile nanofibers/regenerated cellulose (HKUST-1/PANNs/RC) composite aerogel adsorbent, for the adsorption of pollutants in water. This adsorbent was successfully prepared using a simple method combining covalent crosslinking, quick freezing, freeze-drying, in-situ growth synthesis, and solvothermal techniques. The HKUST-1/PANNs/RC composite aerogel exhibits a significantly large specific surface area, which is approximately 64 times greater than that of PANNs/RC (10.45 m2·g−1), with a specific surface area of 669.9 m2·g−1. The PANNs serve as a support framework, imparting excellent mechanical properties to the composite aerogel, enhancing its overall stability and recoverability. Additionally, the composite aerogel contains numerous -COOH and -OH groups on its surface, providing strong acid resistance and facilitating interactions with pollutant molecules through electrostatic interactions, π-π conjugation, n-π* interactions, and hydrogen bonding, thereby promoting the adsorption process. Using methylene blue (MB) as a probe molecule, the study results demonstrate that the HKUST-1/PANNs/RC composite aerogel has an adsorption capacity of 522.01 mg·g−1 for MB (25 h), exhibiting excellent adsorption performance. This composite aerogel shows great potential for application in water pollution control.

Bacterial cellulose-derived porous carbon aerogel containing FeS as the self-supporting anode for high-efficiency lithium-ion storage

Lithium-ion hybrid capacitors (LIHCs) attract extensive attention because of the urgent demands for high-energy density and high-power density devices. Here, a free-standing FeS@C/carbonized bacterial cellulose aerogel (FeS@C/CBC) -based anode for LIHCs is developed by growth of MIL-88-NH2 on bacterial cellulose (BC) substrate, followed by simultaneous carbonization and sulfidation. The obtained FeS@C/CBC inherits the three-dimensional, highly porous structure, and free-standing properties of CBC. FeS is uniformly distributed in the nitrogen-rich carbon and tightly deposited on the CBC fibers, and such structure favors a fast Li/e− transport. As a result, the free-standing FeS@C/CBC delivers a high reversible capacity of 669 mAh g−1 after 1000 cycles at 1 A g−1. Additionally, when the obtained anode is combined with the KCBC as the cathode, the resulting full cellulose-based cell exhibits an impressive cycling stability with the capacity retention of 77.8 % over 10,000 cycles at 5 A g−1 and a high energy density of 172 Wh kg−1 within the voltage window of 0.01–4.2 V, demonstrating a promising potential for practical applications in the field of LIHCs.

Modifications and applications of aerogel prepared with waste palm leaf cellulose in adsorptions for oily contaminations

Abstract Aerogels are essential and effective materials for oily pollution adsorption and recovery. This work described a hydrophobic modified cellulose aerogel using waste palm leaf and its oil adsorption mechanism. By chemical vapor deposition, Methyltrimethoxysilane (MTMS) was employed as a hydrophobic modifier for aerogel of waste palm leaf cellulose at 80 °C for 5 h, and the modified aerogel demonstrated exceptional and stable hydrophobicity with a water contact angle of 132.4° that can still be maintained above 120° after two months of air exposure. After 10 adsorption and extrusion cycles, kerosene adsorption capacity can still reach over 18 times its weight with good regeneration and reuse performance. The kinetic analysis found that the pseudo-second order model was more appropriate for the aerogel’s oil absorption process, including mainly physical adsorption at the beginning and the following chemical adsorption. Owing to its low cost, hydrophobicity, high absorption capacity, and favorable reusability, this aerogel is expected to be used in oils, organic solvent spill cleanup, and oil/water separation fields.

Flexible g-C3N4@bacterial cellulose aerogels for integrated indoor air purification

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Synthesis strategies, regeneration, cost analysis, challenges and future prospects of bacterial cellulose-based aerogels for water treatment: A review

Clean water is an integral part of industries, agricultural activities and human life, but water contamination by toxic dyes, heavy metals, and oil spills is increasingly serious in the world. Aerogels with unique properties such as highly porous and extremely low density, tunable surface modification, excellent reusability, and thermal stability can contribute to addressing these issues. Thanks to high purity, biocompatibility and biodegradability, bacterial cellulose can be an ideal precursor source to produce aerogels. Here, we review the modification, regeneration, and applications of bacterial cellulose-based aerogels for water treatment. The modification of bacterial cellulose-based aerogels undergoes coating of hydrophobic agents, carbonization, and incorporation with other materials, e.g., ZIF-67, graphene oxide, nanoparticles, polyaniline. We emphasized features of modified aerogels on porosity, hydrophobicity, density, surface chemistry, and regeneration. Although major limits are relevant to the use of toxic coating agents, difficulty in bacterial culture, and production cost, the bacterial cellulose aerogels can obtain high performance for water treatment, particularly, catastrophic oil spills.

Oil/water separation with hydrophobic/oleophilic silica-shelled cellulose aerogels

In this work, hydrophobic/oleophilic cellulose/SiO2 aerogels are prepared by coating cellulose aerogels which are prepared from freeze-drying aqueous cellulose solutions with a layer of silica shell and then hydrophobizing the surface by reacting with vaporized methyltrimethoxylsilane. With the cellulose content in the aqueous solution increases from 0.5% to 1.25%, the density of the cellulose/SiO2 aerogel increases from 28.92 mg/cm3 to 34.83 mg/cm3, and the porosity decreases from 90.2% to 84.48%. The structure and composition of cellulose/SiO2 aerogel are analyzed with SEM, FT-IR, XPS, and TGA. The surface wettability investigation indicates that the prepared cellulose/SiO2 aerogels have excellent hydrophobicity and oleophilicity, with a water contact angle up to 143° and an oil contact angle down to 0°. The results of oil absorption experiments show that the absorption capacity of the aerogels for oils and organic solvents is 16∼40 times their own mass. In addition, as the aerogels are hydrophobic/oleophilic, they demonstrate good oil-selective absorption performance in oil/water mixture. Moreover, experimental results in oil absorption under high temperature conditions and acidic/basic conditions indicate that the aerogels have exceptional resilience towards arduous conditions. These advantages render them a viable option for remediation of water pollution resulted from oil contamination.

Supramolecular cross-linking affords superelastic and fatigue-resistant cellulose-based nanocomposites with excellent thermomechanical properties and waterproofing performance

Nanocellulose is one of the most abundant renewable resources on earth and is used in many applications due to its excellent physical and chemical properties, and it is an important biopolymer raw material to support human well-being. However, current cellulose-based aerogel nanocomposites are plagued by irreconcilable contradictions between thermomechanical and waterproofing characteristics due to their hygroscopicity. Herein, sustainable insulating cellulose aerogel nanocomposites are prepared from tempo-oxidized bamboo cellulose nanofibrils (CNFs) and polyvinyl alcohol (PVA) with a continuous orientation-free pore architecture formed by CNFs/PVA pre-hydrogel aggregates, which combine to become the basic structural unit for producing superelastic properties. The resulting lightweight CNFs/PVA aerogels (CNPA) with a hierarchical orientation-free pore architecture and density about 5–20 kg m3 achieve an optimal thermomechanical and insulation trade-off, demonstrating temperature-invariant compressibility (–100–500 ℃) and a low thermal conductivity of 38.2 mW m–1 K–1 at 300 ℃. Particularly, the flyweight CNPA retained its structural integrity after more than 106 cycles at ɛ=20 %, 105 cycles at ɛ=50 %, and 104 cycles at ɛ=80 %. Furthermore, CNPA also exhibits robust liquid-repellency with a WCA exceeding 160.3°. This lightweight cellulose-based nanocomposites, although constructed using an intrinsically hygroscopicity nanocellulose-constituent, is simultaneously superelastic, fatigue-resistant, thermomechanical, and waterproofing performance.

Date palm wood-derived cellulose aerogel dissolved in ionic liquids as a green thermal insulation construction material

Heat insulation materials used in the construction industry are essential for energy conservation. Nonetheless, the majority of current commercial heat insulators are fossil-fuel derived materials; thus, it is vital to provide sustainable, biodegradable, and environmentally friendly alternatives. In this work, an innovative method for producing cellulose II aerogels extracted from date palm waste and from microcrystalline lab-grade cellulose, targeting thermal insulation applications in the construction industry was introduced. A key aspect of the investigated approach is the use of a co-solvent system that combines 1-butyl-3-methylimidazolium chloride (Bmim)Cl and dimethylformamide (DMF), chosen for its efficiency in dissolving cellulose. The cellulose (at 3, 5, 7, and 9 wt%) was dissolved in a co-solvent system of 70 wt% (Bmim)Cl ionic liquid and 30 wt% DMF, saving costs associated with using purely ionic liquid solvents. The prepared aerogels exhibited low thermal conductivity (0.033–0.065 W/m⋅K), low densities (0.08–0.15 g/cm3), high porosity (89.85–94.69 %) and good thermal diffusivity (0.06–0.022 mm2/s). Furthermore, the developed insulators required a compressive strength of 75 kPa to reach 50 % strain and exhibited a sound absorption coefficient of 0.9. Structural characterization of the materials, including X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis, highlights the prospect of cellulose extracted from date palm wood in aerogel preparation and the potential for the (Bmim)Cl/DMF co-solvent system in dissolving cellulose.

Cellulose aerogel beads and monoliths from CO2-based reversible ionic liquid solution

The CO2-based reversible ionic liquid solution of 1,1,3,3-tetramethylguanidine (TMG) and ethylene glycol (EG) in dimethyl sulfoxide (DMSO) after capturing CO2, (2[TMGH]+[O2COCH2CH2OCO2]2−/DMSO (χRILs = 0.1), provides a sustainable and effective platform for cellulose dissolution and homogeneous utilization. Highly porous cellulose aerogel beads and monoliths were successfully prepared via a sol-gel process by extruding cellulose solution into different coagulation baths (NaOH aqueous solution or alcohols) and exposing the cellulose solution in open environment, respectively, and followed by different drying techniques, including supercritical CO2-drying, freeze-drying and air-drying. The effect of the coagulation baths and drying protocols on the multi-scale structure of the as-prepared cellulose aerogel beads and monoliths were studied in detail, and the sol-gel transition mechanism was also studied by the solvatochromic parameters determination. High specific surface area of 252 and 207 m2/g for aerogel beads and monoliths were achieved, respectively. The potential of cellulose aerogels in dye adsorption was demonstrated.

Synergistic adsorption of real phosphorus-containing domestic wastewater by in-situ growth of MgFe-layered double hydroxides co-doped with dual-functional lignosulfonate and La(OH)3 on wood-derived cellulose aerogel

Recovering and reusing of phosphorus (P) in wastewater is the optimal solution to address mineral shortages and eutrophication. Here, the layered double hydroxides (LDHs) grown on wood-derived aerogels (WAs) were prepared after screening the powdered precursors and named La/MgFe-LDH(LS)@WAs. The intricate pore structure and surface morphology of the WAs formed a fibrous network with ultra-low density, good strength and elasticity, allowing for uniform loading. The sample exhibited excellent adsorption capacity of 139.5 mg P/g at pH 4.0, and over 100.0 mg P/g within a wide pH range (3.0–8.0). Thomas and Yoon-Nelson models could effectively describe the dynamic adsorption process. Microscopic morphology and textural characteristics of the samples were characterized and molecular dynamics (MD) simulations and theoretical calculations based on density functional theory (DFT) were used to study the interaction mechanisms. The coordination bonds and weak interactions between the active component LS and La(OH)3 with phosphates were characterized using interaction region indicator (IRI) and independent gradient model based on Hirshfeld molecular density partitioning (IGMH) methods. The atomic δg index mapped to the molecular structure vividly illustrated the maximum contribution of hydroxyl hydrogen to phosphate deprotonation oxygen in inter-fragment interactions on LS. Combining the formation of Me-O-P bonds characterized by X-ray photoelectron spectroscopy (XPS), the mechanism involves weak interactions (hydrogen bond) and chemical adsorption via ligand exchange. High removal efficiency was demonstrated in real wastewater. A method for waste reuse was also proposed. Plant cultivation experiments showed that La/MgFe-LDH(LS)@WAs could sustain wheat growth with slowly degrade and maintain high phosphate availability. The composite shows potential for water restoration, waste treatment, and value-added conversion in the production of controlled-release fertilizers.

Dual-network PVA fiber-doped cellulose aerogel with labyrinth structure for low and medium frequency acoustic and flame retardant applications

Dual-network PVA fiber-doped cellulose aerogel with labyrinth structure for low and medium frequency acoustic and flame retardant applications

Preparation of carboxymethyl cellulose/graphene oxide/ZIF-8 aerogels for efficient methylene blue adsorption

Despite the promising potential of zeolitic imidazole framework-8 (ZIF-8) for dye adsorption, addressing challenges such as aggregation and recycling difficulties remains essential. Herein，a novel three dimensional (3D) carboxymethyl cellulose (CMC), graphene oxide (GO) and ZIF-8 hybrid aerogel (CGZ-3) was prepared via blending ZIF-8 into the CMC-GO matrix. The structure and composition of CGZ-3 were characterized by SEM, FT-IR, TG and XPS. Adsorption experiments were conducted to optimize various parameters affecting the behavior of methylene blue (MB) adsorption. The composite aerogel exhibited an obvious lamellar network structure, with a surface rich in oxygen-containing functional groups such as -OH and -COOH. CGZ-3 demonstrated a rapid adsorption rate for MB, achieving a removal efficiency of 96% within 15 minutes. The entire adsorption process was spontaneous and endothermic, consistent with the pseudo-first-order kinetic model and Langmuir adsorption isotherm model. The maximum theoretical adsorption capacity was 427.35 mg/g at 298 K. Selective adsorptions tests demonstrated high selectivity of the composite aerogel for MB, and dynamic adsorption further confirmed the exceptional adsorption capacity of CGZ-3. After five cycles of adsorption-desorption, the MB removal rate remained above 95%, with an adsorption capacity exceeding 240 mg/g, highlighting the stability and reusability of CGZ-3. Collectively, the CGZ-3 would be a potential material for the adsorptive removal of MB in practical water treatment.

Covalent crosslinking tetraethylenepentamine/cellulose composite aerogels with adsorbability for dye elimination

The cellulose-biomass material possesses a distinctive structure, distinguished by its eco-friendliness, degradability, renewability, cost-effectiveness, and efficacy as a bio-absorbent. In this groundbreaking study, we synthesized cellulose aerogels for the first time using a combination of sol-gel processing, straightforward chemical crosslinking, and freeze-drying. The functionalized materials exhibit an intricately interconnected three-dimensional porous structure achieved through covalent crosslinking with tetraethylenepentamine (TEPA). The resulting aerogel demonstrated a highly porous structure (exceeding 90%), low density (91.89–114.87 mg/cm3), and abundant surface amine groups advantageous for removing organic dyestuffs. To comprehensively assess the impact of the fabricated aerogel on methylene blue and crystal violet adsorption behavior, a detailed investigation was conducted, considering variables such as cellulose content (1.0–3.0 wt%), TEPA/EtOH/H2O volume ratio (1.0–3.0/5.0/3.0), contact time (0–300 min), and initial dye concentration (25–200 mg/L). As a result, the nitrogen-rich aerogel (with 2 wt% cellulose and TEPA/EtOH/H2O ratio of 2.0/5.0/3.0) exhibited dye adsorption following a pseudo-second-order kinetic model, with adsorption isotherms aligning with the Freundlich model. Thermodynamic assessments indicated that the adsorption process is a spontaneous endothermic reaction. Consequently, these eco-friendly cellulose sponges emerge as promising adsorbents for effective wastewater treatment, highlighting their potential as a sustainable solution in environmental remediation.

Development of silanized bacterial cellulose aerogels for the incorporation of natural oils with healing properties: Copaiba (Copaifera officinalis), bourbon geranium (Pelargonium X ssp.) essential oils and buriti (Mauritia flexuosa) vegetable oil

Bacterial cellulose (BC) represents a promising biomaterial, due to its unique and versatile properties. We report, herein, on purposely-designed structural modifications of BC that enhance its application as a wound dressing material. Chemical modification of the functional groups of BC was performed initially to introduce a hydrophobic/oleophilic character to its surface. Specifically, silanization was carried out in an aqueous medium using methyltrimethoxisilane (MTMS) as the silanizing agent, and aerogels were subsequently prepared by freeze-drying. The BC-MTMS aerogel obtained displayed a highly porous (99 %) and lightweight structure with an oil absorption capacity of up to 52 times its dry weight. The XRD pattern indicated that the characteristic crystallographic planes of the native BC were maintained after the silanization process. Thermal analysis showed that the thermal stability of the BC-MTMS aerogel increased, as compared to the pure BC aerogel (pBC). Moreover, the BC-MTMS aerogel was not cytotoxic to fibroblasts and keratinocytes. In the second step of the study, the incorporation of natural oils into the aerogel's matrix was found to endow antimicrobial and/or healing properties to BC-MTMS. Bourbon geranium (Pelargonium X ssp.) essential oil (GEO) was the only oil that exhibited antimicrobial activity against the tested microorganisms, whereas buriti (Mauritia flexuosa) vegetable oil (BVO) was non-cytotoxic to the cells. This study demonstrates that the characteristics of the BC structure can be modified, while preserving its intrinsic features, offering new possibilities for the development of BC-derived materials for specific applications in the biomedical field.

Application of Three-Dimensional Porous Aerogel as Adsorbent for Removal of Textile Dyes from Water

The textile industry is one of the most important industries in the European Union. The main environmental problems of the textile industry are the high water consumption, the generated pollution, the variety of chemicals used and the high energy demand. Recently, adsorbents with a large specific surface area and low weight, such as aerogels, have attracted great interest as promising materials for removing dyes from polluted water. Cellulose aerogels are inexpensive and non-toxic. Langmuir and Freundlich isotherms were chosen as the best method to describe the performance of the adsorbent. In this study, the adsorption efficiency of Congo red, Naphthol green B, Rhodamine B and Methylene blue were determined by using an adsorbent synthesized from paper and cardboard waste. The total organic carbon concentration was chosen as an indicator of the concentration of the dyes in the solutions. The aerogel capsules had 5% cellulose content. It was found that the adsorption capacity of the aerogel in the solutions of Congo red varied from 0.028 mg/g to 14.483 mg/g; in the solutions of Naphthol green B, from 0.013 mg/g to 7.698 mg/g; in the solutions of Rhodamine B, from 0.020 mg/g to 8.768 mg/g; and in the solutions of Methylene blue, from 0.024 mg/g to 13.538 mg/g.

Simultaneously enhanced the sound absorption coefficient and dimensional stability of Carboxymethyl cellulose/clay aerogel by impregnating polyurethane

Carboxymethyl cellulose (CMC) aerogel could be used in the manufacture of highly efficient sound-absorbing materials because of its low density and sustainability. However, owing to its low mechanical strength and brittleness, preparing porous sound absorption materials with excellent sound absorption performance has always been a challenging problem. Herein, carboxymethyl cellulose/organic exfoliation of montmorillonite/thermoplastic polyurethane (CMC/OMMT/TPU) composite aerogels were successfully obtained via a simple impregnation and freeze-drying process. The effect of TPU and OMMT on the sound absorption properties of cellulose aerogels was detailedly discussed. The results revealed that the CMC/OMMT/TPU composite aerogel had hierarchically porous structures, and the sound absorption performance was significantly improved. The average sound absorption coefficient of CMC/OMMT/TPU composite aerogel could reach as high as 0.807 (500–6500 Hz). The main reason for this improvement is caused by the multiple scattering of sound waves on the arranged porous surface, as well as the viscous damping of the air inside the structure between the TPU, CMC and OMMT. Furthermore, the dimensional stability of the prepared aerogel is also greatly enhanced after using TPU. This work provides a new approach for the development of aerogel with stable morphology and sound absorption performance, which would be widely used in construction and military fields.

Construction of highly robust amino orange peel cellulose for Cu2+ adsorption study

ABSTRACT In this paper, a kind of cellulose aerogel (HRCNFs) with high mechanical robustness and durability was prepared by using orange peel cellulose and polyethylenimine, and it was used for high-efficiency adsorption of Cu (II). Fourier analysed the structure and morphology of HRCNFs transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), and the pore structure characteristics of the materials were evaluated by BET. The adsorption capacity of HRCNFs as adsorbent to remove Cu (II) ions from aqueous solution was further studied. The maximum adsorption capacity was 167.21 mg/g. Adsorption is mainly a single-layer chemisorption process. Based on FTIR and BET analysis, the adsorption mechanism is the strong surface complexation of amino, carboxyl, and hydroxyl groups with Cu (II). Through many cycles, HRCNFs retain their integrity and high mechanical robustness. Therefore, the synthesised HRCNFs material can be considered a promising adsorbent for the removal of Cu (II) ions from polluted water bodies.

Cellulose-based aerogel derived N, B-co-doped porous biochar for high-performance CO2 capture and supercapacitor

The remarkable characteristics of porous biochar have generated significant interest in various fields, such as CO2 capture and supercapacitors. The modification of aerogel-derived porous biochar through activation and heteroatomic doping can effectively enhance CO2 adsorption and improve supercapacitor performance. In this study, a novel N, B-co-doped porous biochar (NBCPB) was synthesized by carbonating and activating the N, B dual-doped cellulose aerogel. N and B atoms were doped in-situ using a modified alkali-urea method. The potassium citrate was served as both an activator and a salt template to facilitate the formation of a well-developed nanostructure. The optimized NBCPB-650-1 (where 650 corresponded to activation temperature and 1 represented mass ratio of potassium citrate activator to carbonized NBCPB-400 precursor) displayed the largest micropore volume of 0.40 cm3·g−1 and a high specific surface area of 891 m2·g−1, which contributed to an excellent CO2 adsorption capacity of 4.19 mmol·g−1 at 100 kPa and 25 °C, a high CO2/N2 selectivity, and exceptional reusability (retained >97.5 % after 10 adsorption-desorption cycles). Additionally, the NBCPB-650-1 electrode also delivered a high capacitance of 220.9 F·g−1 at 1 A·g−1. Notably, the symmetrical NBCPB-650-1 supercapacitor exhibited a high energy density of 9 Wh·kg−1 at the power density of 100 W·kg−1. This study not only presents the potential application of NBCPB-650-1 material in CO2 capture and electrochemical energy storage, but also offers a new insight into easy-to-scale production of heteroatomic-modified porous biochar.

Preparation of amino cellulose aerogel and its formaldehyde adsorption properties

The aerogel prepared from cellulose has the advantages of low density, high porosity, large specific surface area, good gas diffusion and adsorption space, which is a good gas adsorption material. In this study, microcrystalline cellulose was used as raw material, and LiBr ionic liquid was used as a solvent system. In addition, cellulose aerogel was modified by polyethyleneimine, which retained three-dimensional network structure and had excellent formaldehyde adsorption capacity. The adsorption capacity of polyethyleneimine-modified cellulose aerogel (PCA) to formaldehyde can reach 12.3 mg/g at 25 ℃. It was found that the adsorption capacity of PCA aerogel for formaldehyde changed with the increase in nitrogen content. The adsorption of formaldehyde was mainly through the chemical adsorption of the Schiff base reaction between NH2 and formaldehyde molecules in polyethylenimine (PEI).