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Cellulose aerogels are a new category of high-efficiency adsorbents for treating oil spills and water pollution. However, the hydrophilic properties and recyclability of aerogels ...after adsorption hamper developments and applications. Combining both hydrophobic and magnetic properties are expected to improve their adsorption capacity and functionality.
In this study, the effect of oleic acid (OA) and nanomagnetite on the preparation of magnetic nanocellulose aerogels (called as NCA/OA/Fe3O4) by a mechanical mixing combined with freeze-drying method have been investigated.
It has been found that the optimal condition for fabricating this NCA/OA/Fe3O4 aerogel is 0.4 wt% nanocellulose, 3 mg mL−1 OA and 0.5 wt% Fe3O4 in the aqueous solution. This aerogel has a very low density of 9.2 mg cm−3 and demonstrates a high adsorption capacity of 68.06 g g−1 for cyclohexane. In addition, this aerogel adsorbent demonstrates an excellent magnetic responsivity and can be easily recycled by a permanent magnet after adsorption. As a consequence, this hydrophobic magnetic NCA/OA/Fe3O4 aerogel is promising not only for easy oil and organic solvent adsorption but also potentially for other magnetic related applications.
The self-assemble hydrophobic aerogel-like hollow boehmite microspheres adsorbents were prepared by surface silylation modification method using methyltrimethoxysilane silanizing agent. The density ...of the adsorbents was as low as 0.1 g/cm3, the average pore diameter was 12.2–15.3 nm, and the water contact angle was 130°∼143.8°. The hollow microsphere adsorbents could uptake 8.51 g/g for engine oil, 8.42 g/g for peanut oil, 7.29 g/g for kerosene and 5.80 g/g for n-hexane. After 20 regeneration cycles in n-hexane, the regeneration rate of the adsorbent was still as high as 95.17 %，meaning adsorption capacity of the adsorbent did not decrease significantly. The aerogel-like hollow boehmite microspheres with good hydrophobicity can be used as a kind of potential candidate material to remove different oils and organic liquids.
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•The HAHBM microspheres adsorbents were prepared by for removing oils and organic liquids.•The average pore diameter of the adsorbent is 12.2–15.3 nm, and the water contact angle reaches 143.8°.•The adsorbent can uptake various oils and organic liquids, such as 8.51 g/g engine oil and 5.80 g/g n-hexane.•After 20 regeneration cycles, the regeneration rate of the adsorbent is still as high as 95.17 %.
Super light 3D nanocellulose aerogel foam was built and demonstrated superior oil adsorption capability.
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In this work, the concentration effect of both nanocellulose and sodium ...dodecylsulfate (SDS) on the fabrication of a super light 3D hierarchical framework adsorbent nanocellulose aerogel foam (NAF) is exploited through a high speed mechanical foaming and solvent-free method by adding SDS. The results show that the optimal concentration of nanocellulose and SDS for preparation of this 3D NAF/SDS is 0.4 and 0.2 wt%, accordingly. By utilizing unique gridding framework of NAF/SDS, a low density of 1.50 mg cm−3 and high adsorption capacity of 206.79, 194.75 and 145.20 g g−1 towards cyclohexane, ethyl acetate, and vacuum pump oil, accordingly, are achieved in the as-prepared NAF/SDS, which is much higher than that of conventional nanocellulose aerogel (NA) (52.07, 81.12 and 34.52 g g−1, respectively). The results illustrate that this NAF/SDS is a promising candidate for preparing 3D hierarchical network structure from natural polymer cellulose in an environmental control for oil adsorption.
In this study, inorganic-organic hybrid sorbent SBA-15-Fe3O4-PDA-ODA with functional groups having affinity for both water-soluble and insoluble pollutants was synthesized for treatment of wastewater ...where Malachite Green (MG) dye and motor oil coexist. In order to enhance the specific interactions between the sorbent and dye via functional groups of polydopamine (PDA), Fe3O4 nanoparticles were encapsulated with SBA-15 and surface functionalization with PDA was accomplished and then the surface of Fe3O4-SBA-15-PDA was modified with octadecylamine (ODA) to remove the oil present in the same environment with dye. While the SBA-15-Fe3O4-PDA-ODA directed to the aqueous phase by magnet provided MG removal thanks to the hydrophilic groups of PDA, it provided motor oil removal thanks to hydrophobicity of ODA when directed to the oil phase. 99.20 % dye removal and 9.24 g/g oil adsorption capacity were achieved from the environment where oil and dye were present together. Besides, the adsorption of MG on Fe3O4-SBA-15-PDA was searched at various pH, dye concentration, adsorbent dosage, and temperature in order to propose optimum experimental conditions for removal of dye and maximum adsorption capacity was determined as 95.83 mg g−1 at optimum conditions (10 mg adsorbent, 10 mg L−1 MG concentration, pH 9). Interaction mechanism between dye and Fe3O4-SBA-15-PDA was explained by studying the adsorption behavior of sorbent derived from the isotherm and kinetic results. The sorbents were characterized by FT-IR, XRD, SEM, N2-adsorption/desorption, water-contact-angle, and VSM measurements. SBA-15-Fe3O4-PDA-ODA sorbent was tested for three successive adsorption cycles for both dye and oil and eventuated insignificant loss in activity when they were recycled. Easy and low-cost fabrication protocol, controllable removal ability of dye and oil will facilitate its versatility in environmental cleanup process for water soluble and insoluble pollutants.
•Treatment of wastewater where soluble and insoluble pollutants coexist is aimed.•Inorganic-organic SBA-15-Fe3O4-PDA-ODA adsorbent was synthesized and characterized.•Polydopamine and octadecylamine parts serve as dye and oil remover respectively.•Removal of soluble dye and insoluble oil could be controlled by magnetic steering.
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•Compressible wood adsorbent with ecological merits for oil-spill collection.•Photothermal effect induced adsorption of high-viscous crude oil pollutants.•Nature derived structure for ...efficient adsorption and compressible recovery.•Fast photothermal effect as temperature reach up to 88 °C within 100 s under 1 sun.•Potential mechanisms reveal by Computational Fluid Dynamics calculation.
An efficient collection and recovery of high-viscous crude-oil from oil spillage through an environmental-friendly way is extremely important for water remediation. Herein, a new material of thermally-reduced graphene-oxide coating and decoration of hydrophobic-layer over a compressible wood-sponge was proposed as an adsorbent. Owing to the preferable photothermal conversion, an in-situ solar-assisted thermogenesis process could increase the temperature to 88 °C within 100 s under 1 sun illumination and decrease the viscosity of crude-oil for easy adsorption. The fabricated adsorbent exhibited great performances in separation and adsorption (7.28 g/g–0.801 g/cm3) of oil-spill; with fully active-collection of 50 mL crude-oil within 20 min. Numerical modeling was also employed to gain an in-depth understanding of the adsorption and regeneration processes. The temperature gradient and structural dots subjected to compression stress for both photothermal induced adsorption and compressible recovery of crude oil were investigated as the dominant factors. The adsorbent also exhibited satisfactory adsorption and separation capacities for common light oils and heavy oils. Moreover, the adsorbent could be employed for feasible adsorption in semi-open seawater-environment under light, showing potential for practical treatment of offshore oil-spillage. This work designed a potential route to overcome the dilemma of crude-oil adsorption, due to its inherent high-viscosity, through in-situ photothermal thermogenesis using environment-friendly materials derived from natural wood. The knowledge obtained from this work would help in developing novel adsorbents with applied and ecological merits and further understanding of the related mechanisms.
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•Polypropylene (PP) fiber felts were produced on a large scale by melt-blown technology.•UV irradiation-induced dopamine polymerization for accelerated mussel-inspired surface ...modification.•The magnetism imparts remote controllability of the fiber felt.•Multi-size micromorphology thrilling superior oil absorption capacity.•Serving as oil trap to recover spilled oil and separate the oil/water mixture.
In response to the defects of low oil adsorption capacity and poor oil–water selectivity of polypropylene fiber felt as an oil spill emergency material, which necessitates systematic improvement to cope with frequent oil spills. Herein, a superhydrophobic magnetic fiber felt is fabricated by a facile melt-blown technique and a rapid modification process to solve its defects while imparting its functionality. UV-induced rapid polymerization of dopamine on melt-blown fibers and a dip coating of hydrophobic candelilla wax to modify mussel-inspired oil-adsorbent felts. The resultant felt features remote controllability as well as thermal and mechanical stability, exhibiting high resistance to corrosive solutions. The adsorption efficiency of the modified felt is significantly enhanced with a capacity of 10–20.48 g/g, and notably, it can be recycled 15 times via manual adsorption–desorption, which greatly contributes to the usefulness of the adsorbent. In addition, the separation efficiency of the felt applied as a membrane exceeds 95.7 % for various oil–water mixtures by gravity alone and a permeate flux of up to 28,662 L·m−2·h−1. A pump-assisted experiment connected to a felt can collect oil at a flux of 20,845 L·m−2·h−1, aiming at the continuous recovery of oil spills from seawater. The significant advancement in oil-adsorbent felt provides engineers with a more realistic strategy to handle oil spills and challenging separations.
The cleanup of spilled oil from water has always been a severe and urgent issue, which attracted great attention and interest. In this study, we reported a highly efficient large-scale blow spinning ...technique to fabricate fibrous oil sorbents including the polystyrene (PS) fibrous sponge and polyvinylidene fluoride (PVDF)/polystyrene (PS) composite package with ultrahigh oil adsorption capacity. The wide diameter distributions and multilevel pore structure of PS fibers were obtained by controlling the precursor solution compositions used in blow spinning. The PS fibrous sponge formed by accumulating naturally exhibited an ultralow density, whose oil adsorption capacity ranged from 74 to 440 g/g for various oils and organic solvents. To enhance the mechanical strength of the PS fibrous sponge, the PVDF/PS composite package with the sandwich structure was fabricated by alternately blow spinning. The PVDF/PS composite package possessed 2.7 times the tensile strength of the PS fibrous sponge while the oil adsorption capacity had merely a slight decrease. Moreover, the fabrication strategy of blow spinning used to produce the fibrous sponge and composite package is highly efficient, cost-effective, and environment-friendly, which is suitable for large-scale industrial production of oil sorbents and oil spill cleanup in environment protection.
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•A green and cost-effective method to convert corn stover into aerogel has been developed.•The modified aerogels were utilized for adsorption of oils and emulsions separation.•The ...maximum absorption of carbon tetrachloride as example of oil waste reaches 75 g/g.•The super-hydrophobic crosslinked aerogels exhibited good recyclability.•The aerogel is superlative adsorbent for remediation of polluted water.
Owing to the excellent adsorption capacity and high selectivity, aerogel have attracted considerable attention recently as promising sorbent materials for oil–water separation. Although many preparation methods for aerogel have been reported, green, facile, and low-cost fabrication is still a challenge. Herein, we reported the preparation of superhydrophobic and superoleophilic aerogel for oil and organic solvents collection from water. The crushed corn stover was treated with sodium hydroxide and hypochlorous acid to obtain the biomass cellulose fibers. The aerogels were produced using polyvinyl alcohol binder, followed by a freeze-drying method. It showed high porosity (98.26–99.01%) and low density (15.15–24.95 mg/cm3). After modified with hexadecyltrimethoxysilane by chemical vapor deposition, the aerogel exhibited superior superhydrophobicity and showed excellent adsorption capacity (75 g/g). The adsorbed oil and organic solvents can be recovered by extrusion or centrifugation, and the aerogel showed stable performance and excellent reusability. Besides, the aerogel can separate various water-in-oil emulsions with separation efficiencies up to 99.94% and flux as high as 5529 L•m−2•h−1. Taken together, the results illustrate that the aerogel hold promise for the fields of oil recovery and environmental protection.
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The preparation of high-expansion open-cell foam for oil spill clean-ups is important, but still challenging with linear isotactic polypropylene (PP). Therefore, a cooling batch ...foaming method was designed to fabricate the high-expansion PP foams using supercritical CO2 as a blowing agent. To investigate the relation between the crystallization and foaming of PP, an in-situ visualization system was employed. It is found that the CO2 dissolved in polymer melt depresses the crystallization temperature and nucleation of PP. When the foaming is triggered before the crystallization, high-expansion foams can be prepared. Moreover, foaming occurring before crystallization helps to produce an open-cell structure owing to a structural inhomogeneity induced by the PP crystallization. According to the hydrophobicity and oil absorption capacity tests, the open-cell foam prepared at 20 MPa and 135 °C exhibits a large water contact angle of 151.5° and a high adsorption capacity of 48.9 g/g for carbon tetrachloride. Further, it exhibits an excellent reusability for oil recovery in the cyclic adsorption and squeezing process. Therefore, the fabricated high-expansion open-cell foam shows good application prospects in oil spill clean-up fields.
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•Lightweight bio-aerogels with interconnected pores were prepared in a facile way.•The introducing of microbubbles apparently improves the mechanical performances.•The adsorption ...capacity of the MGS aerogels for oils could be up to 68–130 g/g.•The further modified MGS aerogels can selectively collect oils from water.•Offering a way for preparing porous bio-aerogels with good mechanical properties.
Aerogels with low density, high porosity and exceptional mechanical properties have attracted great interest as adsorbents. Preparing bio-based aerogels with high porosity and outstanding mechanical performance via a facile and green strategy is in a growing demand. In this paper, an effective approach was put forward to prepare porous lightweight bio-aerogels by introducing extensive microbubbles during gelation of gelatin, which not only endows aerogels with abundant and interconnected pores to ensure the low density and high adsorption capability, but also improves the elastic resilience and fatigue resistance of the formed aerogels. In addition, after further going through silylation treatment, the hydrophobically modified porous aerogels maintain the good mechanical stability, and efficiently collect oils/organic solvents from water. Considering the low-cost, greenness of the preparation process and high performance of the prepared aerogels, this approach holds a promising potential in preparing porous bio-based aerogels with excellent mechanical properties for controlling environmental pollution caused by petroleum products and toxic organic solvents.
