Oil Adsorption Capacity Research Articles

Preparation of superhydrophobic polyurethane sponge with photodegradation function and study on its oil-water separation performance

The surface of tetrapod-shaped zinc oxide whiskers (T-ZnOw) was hydrophobized by the sol-gel method, and then loaded onto the surface of polyurethane sponge by dip-curing method to prepare a superhydrophobic polyurethane sponge with photodegradation function. When the mass ratio of superhydrophobic tetrapod-shaped zinc oxide whiskers (ST-ZnOw) and polydimethylsiloxane (PDMS) was 0.5:1, the water contact angle of the sponge was 157.5°. After being soaked in acid and alkali corrosion solution, rubbed with sandpaper and heat treated, the sponge can still maintain excellent hydrophobic properties. The adsorption capacity for different oils and organic solvents is 12 to 35 times of its own mass. After repeated extrusion-oil absorption experiments, it can still maintain its good adsorption capacity and high hydrophobicity, showing excellent reusability. The continuous oil-water separation efficiency of the material for different oils and organic solvents is above 95%, and the separation efficiency for the emulsion prepared with span80 content of 0.1wt% is 99.84%. At the same time, the prepared material can degrade the organic dye methylene blue under ultraviolet light, with a degradation rate of 99.35%, showing excellent potential for degrading organic pollutants.

Superhydrophobic, Conductive and Magnetic Sponge for High Performance Oil-water Separation and Recycled Oil Absorption

Nowadays, the frequent occurrence of oil spills at sea has caused serious pollution to the ecosystem and has led to a gradual decrease in marine resources. Conventional adsorbent materials have difficulty absorbing high-viscosity oils and separating oil from water, and recycling still has great challenges. We developed a novel superhydrophobic, magnetic, and photo-thermal sponge (SMPS) with a simple preparation method, which is composed of polyurethane (PU) sponge, polydopamine (PDA), acidified carbon nanotubes (ACNTs), ferric tetroxide (Fe3O4), and polydimethylsilane (PDMS), modified by self-polymerization, ultrasonication, and soaking. The modification of ACNTs, Fe3O4, and PDMS further enhances the electrical conductivity, magnetism, photo-thermal effect, and superhydrophobicity of the PU sponge. The SMPS (PU/PDA/ACNTs-Fe3O4/PDMS) can reach a water contact angle of 168.32°, which can still be maintained at 150° in harsh environments, and it has a good oil adsorption capacity (up to 31.06g/g) and an oil-water separation efficiency of 96%. In addition, the SMPS has an excellent photo-thermal effect (surface temperature up to 204.9 ℃) for better adsorption of high-viscosity oils. It can also be used for oil adsorption and recycling in local areas through its own magnetism. This paper has studied PU sponges with superhydrophobic, magnetic, and photo-thermal performance, which provides a new research idea for large-scale, regional cleaning and recycling of marine high-viscosity oil pollution.

Applications of three-dimensional whey protein amyloid fibril-based hybrid aerogels in oil/water separation and emulsion separation.

Environmental contamination from oil spills and industrial wastewater poses long-term risks to ecosystems and human health. Amyloid fibrils' superior stiffness and stability, outstanding biocompatibility and biodegradability, versatile functional groups, and high specific surface area make them promising sustainable adsorbents. This study is aimed at examining the application of three-dimensional polysaccharide-modified whey protein amyloid fibril (WPIAF) aerogels in oil/water separation and emulsion separation. The WPIAF aerogel was first synthesized through the salting out method coupled with lyophilization, then modified using carboxymethyl cellulose (CMC) or chitosan (CS). Our results showed that WPIAF aerogels exhibited increased mechanical properties and surface hydrophobicity after polysaccharide modification. The CS-modified WPIAF aerogels showed better oil adsorption capacities, oil adsorption capability, and reusability than WPIAF aerogel and CMC-modified WPIAF aerogels. Furthermore, the applicability of polysaccharide-modified WPIAF aerogels in a continuous oil/water separation system was demonstrated. Finally, the separation efficiencies of polysaccharide-modified WPIAF aerogels were determined to be over 90 % in various emulsion systems, and the possible separation mechanism was further investigated. This study provides a nice example of applying amyloid-based aerogels for oil/water separation and emulsion separation.

Cellulose acetate-decorated and siloxane-modified hydrophobic melamine foam with excellent selectivity and durability for efficient oil/water separation

The construction of hydrophobic porous adsorption materials, which are cost-effective, green, stable, and efficient, are urgently demanded for the large-scale and effective oily wastewater treatment. Herein, a facile and low-cost two-step fabrication strategy of hydrophobic melamine foam (MF) was demonstrated, including cellulose acetate (CA) decoration and siloxane modification. Cellulose acetate initially assembled on the skeleton of MF with the aid of hydrogen bond formation between the hydroxyl groups of CA and imimo groups of MF. At an optimal concentration of CA, the as-prepared composite foam (CA/MF) exhibited good hydrophobicity. To further improve the oil/water selectivity, the above foam was enhanced by chemical vapor deposition (CVD) of methyltrimethoxysilane (MTMS). The successful silicification reaction between CA/MF and MTMS decreased the surface energy and improved the surface topological structure, leading to excellent hydrophobicity (water contact angle of 147.4°) and superoliophilicty. Such hydrophobized cellulose acetate/melamine foam (H-CA/MF) presented low density, favorable porosity (97.78%), and distinguished pore volume (88.66 mL/g), leading to a high oil adsorption capacity of up to 56.6 g/g. Due to the excellent mechanical elasticity of H-CA/MF, the oil absorption and recovery can be achieved easily by a simple manual adsorption-squeezing method and lab-made pump-assisted separation device with satisfactory recyclability. Moreover, H-CA/MF displayed marvelous stability and environmental adaptability in different harsh environment, further enlarging its practical application scenarios. Along with the green and cost-effective preparation process, the present study provides a facile strategy to fabricate hydrophobized melamine-based foam, which is of great significance for scalable and efficient oil/water separation.

DESIGN AND EVALUATION OF SELF-NANOEMULSIFYING DRUG DELIVERY SYSTEM FOR DEFERASIROX

In order to increase deferasirox’s (DEF) solubility and dissolution rate, the study aims to develop a solid self-nanoemulsifying drug delivery system (S-SNEDDS). The impact of concentrations of oil and surfactant on emulsification and in vitro drug release was investigated using an oil, surfactant and cosurfactant mixture. Based on a minimum time of emulsification and a high cumulative percentage of drug dissolution, the formulation F6 was optimized. The optimized formulation showed an emulsification efficiency of 19 ± 0.67 seconds and in vitro drug release of 98.65 ± 0.259 % in 30 minutes. Neusilin® US2 was used to solidify the formulation, which has a high oil adsorption capacity and better micromeritic characters. The analyses of X-ray powder diffraction and differential scanning calorimetry studies displayed the transformation of DEF from its crystalline form to an amorphous form. So, this study demonstrates that the S-SNEDDS is a viable innovative drug delivery strategy for elevating DEF’s solubility and dissolution rate.

Study on Surface Esterification of Cellulose Nanocrystals Their and Lipid-Lowering Effect

ABSTRACT With the rapid development of the economy and changes in dietary structure, there is an excessive intake of high sugar and high-fat foods. To address this issue, in this study, we grafted palmitic acid onto CNC in the form of ester groups and evaluated its adsorption performance. Research had found that among these three methods, the CDI catalytic method can successfully obtain esterification modified CNC while also taking into account its environmentally friendly and pollution-free characteristics. Compared with CNC, its adsorption capacity for oil had increased, with the maximum adsorption capacity increasing from 35.80 g/g to 46.91 g/g. Meanwhile, the degree of esterification substitution of esterification modified CNC was measured, and the result was 0.03. Especially, after adding CNC-PA, the hydrolysis of fat was significantly reduced during the simulated digestion in vitro, whilst the absorption of fat in the intestine was significantly inhibited. In vivo testing also confirmed that consuming a diet containing CNC-PA significantly reduced elevated levels of triglycerides (TG) compared to the high-fat control group while long-term feeding of a diet containing CNC-PA reduced weight and fat accumulation.

Facile preparation of photothermal and superhydrophobic melamine sponge for oil/water separation and anti-icing

The preparation of superhydrophobic sponges with excellent physiochemical performance, affordability, and versatility is still a big challenge. Herein, a photothermal and superhydrophobic melamine sponge has been successfully achieved by decorating lignin particles (LPs)@MXene composite onto the skeletons of melamine sponge (MS) via the self-polymerization of dopamine. The obtained superhydrophobic MS (labeled as MS@PDA/LPs@MXene) shows a water contact angle of 153.7°, and maintains surface superhydrophobicity under harsh conditions (i.e., acidic, alkaline environments, high temperatures, frictional damage, and icing/de-icing cycles). Notably, the MS@PDA/LPs@MXene exhibits an exceptional oil adsorption capacity of carbon tetrachloride up to 143.6 times of its own weight, a high separation efficiency of 99.3 %, and a retained separation efficiency of 98.9 % after 15 cyclic adsorption processes, respectively. Owing to a synergistic photothermal effect of PDA and LPs@MXene, the MS@PDA/LPs@MXene possesses a maximum surface temperature of 62.8 °C under solar irradiation (1.0 kW/m2, 1 sun), and realizes the ice-free property at a low temperature of −17.9 °C (relative humidity, 90 %) on a continuous cooling stage under solar irradiation (0.5 sun). Furthermore, the LPs@MXene composite coating can be applied on various substrates (i.e., Al sheet, Cu sheet, filter paper, carbon cloth, steel mesh and NdFeB magnet) to obtain surface superhydrophobicity, showing excellent anti-corrosion property for the permanent NdFeB magnet. Thus, this paper proposes a facile and cost-effective strategy to prepare superhydrophobic melamine sponge with multifunctional properties, and provides new insights into the rational design of high-performance superhydrophobic sponges for their applications in oil/water separation and anti-icing.

Enhanced Hydrophobicity and Oleophilicity of Modified Activated Carbons Derived from Agro-Wastes Biomass for the Removal of Crude Oil from Aqueous Medium

Crude oil spillage has tremendous environmental impacts and poses severe pollution problems worldwide due to the continuous activities and operations in the oil and gas sector. This has resulted in the urgent need for clean-up techniques such as the use of natural adsorbents which is considered a relatively low-cost, readily-available, efficient, eco-friendly, and easy-to-deploy mode of addressing oil spillage due to its high oil sorption capacity/efficiency, high oil selectivity, oleophilic, enduring, reusability and biodegradable properties. Empty palm fruit bunch and coconut coir were used as precursors to produce activated carbons for oil spill remediation. The influence of varying parameters was investigated using a batch experimental procedure resulting in the crude oil adsorption capacity increasing with a corresponding increase in contact time, initial oil concentration, temperature, agitation speed, and particle size but decreasing in adsorbent dosage. The combination of surface morphological modification and hydrophobicity enhancement resulted in significantly improved adsorption capacity for crude oil removal (2710.0 mg/g and 4859.5 mg/g for EPFBAC<SUB>LA</SUB> and CCAC<SUB>L.A</SUB> respectively), as evidenced by both FTIR and SEM analyses. The experimental isotherm data were analysed using various isotherm models and the best-fitted isotherm model was the Freundlich model with a correlation coefficient (R<sup>2 </sup>= 0.991 and R<sup>2 </sup>= 0.999) for EPFB<SUB>L.A</SUB> and CCAC<SUB>L.A</SUB> respectively. The kinetic behaviour of the adsorption process was best described by pseudo-second order with R<sup>2</sup> values of 0.970 and 0.999 for EPFBAC<SUB>LA</SUB> and CCAC<SUB>L.A</SUB> respectively while Boyd model revealed that the adsorption was controlled by an internal transport mechanism and film diffusion was the rate-limiting step. The crude oil adsorption was chemisorption and endothermic owing to the positive enthalpy values (ΔH<sup>o</sup> = 183.890 KJ/mol for EPFBAC<SUB>L.A </SUB>and ΔH<sup>o</sup> = 69.656 KJ/mol for CCAC<SUB>L.A</SUB>), the positive value of entropy suggested that the adsorption process was accompanied by an increase in the degree of randomness or disorder at the interface between the adsorbent and the adsorbate. A temperature rise led to a decline in Gibbs energy (ΔG<sup>o</sup>), suggesting that adsorption became more feasible and spontaneous at higher temperatures and the significant activation energies indicated the existence of a substantial energy barrier that must be overcome to initiate the reaction. The results showed the significant capability of the prepared adsorbents to be used as a low-cost, re-generable and eco-friendly adsorbent in oil spill clean-up and is recommended to exploit its usage on a large scale.

Activated Carbon derived from Jackfruit Seeds for Oil Adsorption

Activated carbons (AC) are widely used as adsorbents for treating oily wastewater. An effective, cheap and environmental-friendly method for oil adsorption by using AC derived from jackfruit seeds (JS) was developed in this study. The JS were chemically activated with different concentrations (10 wt.% and 15 wt.%) of chemical activating agents (H3PO4 and ZnCl2) to produce activated carbon. The optimum conditions for developing AC from JS with the highest oil adsorption capacity was found using 15 wt.% ZnCl2, and carbonised at 500°C resulting in maximum adsorption capacity of 0.8621 g/g. Raw JS and jackfruit seed-derived activated carbon (JSAC) were characterized by Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy analysis. The influence of process parameters such as contact times (0 – 240 minutes), adsorbent dosages (0.5 – 2.5 g) and adsorption temperatures (25 – 65 °C) for oil adsorption were investigated. The results showed that the optimum parameters for maximum adsorption capacity were as follows; 120 minutes of contact time, adsorbent dosage of 1.5 g and at 35 °C. At this condition, the highest oil adsorption capacity was achieved at 1.5674 g/g. The adsorption kinetic studies depicted that the oil adsorption mechanism was represented by pseudo-second-order kinetic model which implies that the adsorption is a chemisorption process. Jackfruit seeds had been proven to have the capability as an effective adsorbent for oil adsorption.

Facile Preparation of Smart Sponge Based on a Zeolitic Imidazolate Framework for the Efficient Separation of Oily Wastewater

The fabrication of durable materials with excellent oil-adsorption capacity and separation performance for the treatment of oily wastewater is meaningful based on the special property of smart responsiveness. Herein, a solvent-responsive melamine sponge (MS) was developed via silanization and the in situ growth of a zeolitic imidazolate framework-8 (ZIF-8). Detailed characterization of the resultant composite MS was conducted using scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and X-ray diffraction (XRD). The multiscale hierarchical MS substrate exhibited highly hydrophobic properties in the pH range of 1–11, along with a satisfactory adsorption capacity in the range of 65.4–134.2 g/g for different oils. The modified surface transformed from superhydrophobic/superlipophilic to superhydrophilic/underwater superoleophobic upon ethanol wetting, reverting to its original superhydrophobic state upon drying. The separation flux of the MS substrate was above 1.5 × 104 L/m2h for both oil and water removal, and the separation efficiency was greater than 98.7%. The absence of obvious changes in separation performance after 50 successive immiscible oil−water separations indicated the excellent durability and robustness of the anchored ZIF-8 nanoparticles on the surface of the modified MS substrate. More importantly, oil-in-water emulsion separation was successfully carried out via the ZIF-8 MS composite, showing high separation efficiency (over 99.1%). The developed smart sponge, which had high oil-adsorption capacity, excellent chemical stability, and fire resistance, has a wide range of potential practical applications in the convenient treatment of oily wastewater.

Magnetic, self-heating and superhydrophobic sponge decorated with BN and CoFe2O4 for high-efficient cleanup of crude oil spills using facile co-precipitation strategy

Accidents involving petrochemical spills have repeatedly threatened the security of the eco-environment. The leaked crude oil exhibits poor fluidity, low adsorption efficiency, and urgent issues such as potential fire risks that require immediate attention. Herein, a multifunctional superhydrophobic sponge Si@CFO@BN@PU was prepared by a simple co-precipitation strategy based on BN and CoFe2O4. The results demonstrate that Si@CFO@BN@PU exhibits excellent superhydrophobic properties, with a water contact angle of 162° and a slide angle of less than 10°, and oil adsorption capacity ranging from 32.3 to 68.4 g/g. Furthermore, the modified sponge also possesses certain magnetic properties, allowing Si@CFO@BN@PU to be moved on the water surface via an external magnetic field and effectively adsorb floating oil. Meanwhile, the modified sponge exhibits excellent photothermal properties. The whole sponge can be heated up to 80 °C in just 60 s under simulated sunlight conditions, effectively reducing the adsorption time of viscous oil by 90 %. Moreover, the cone calorimeter test results demonstrate excellent fire safety of Si@CFO@BN@PU even after adsorption of petroleum. The peak heat release rate (pHRR), total heat release (TSR), maximum CO release rate, and maximum CO2 release rate have decreased by 37.8 %, 23.3 %, 45.4 %, and 34.1 %, respectively. Therefore, Si@CFO@BN@PU is an effective, safe and sustainable new adsorbent material with a wide range of applications in treating petrochemical spills.

Lightweight, Elastic, and Superhydrophobic Multifunctional Organic-Inorganic Fibrous Aerogels for Efficient Oily Wastewater Purification and Electromagnetic Microwave Absorption.

Lightweight and robust aerogels with multifunctionality are highly desirable to meet the technological demands of current society. Herein, we designed lightweight, elastic, and superhydrophobic multifunctional organic-inorganic fibrous hybrid aerogels which were assembled with organic aramid nanofibers and inorganic hierarchical porous carbon fibers. Thanks to the organic-inorganic fiber hybridization strategy, the optimal aerogels possessed remarkable compressibility and elasticity. Benefiting from the microscopic hierarchical porous structure of carbon fibers and the macroscopic macroporous lamellar structure of aerogels, the optimal aerogels exhibited superb lightweight property, conspicuous electromagnetic microwave absorption ability, and outstanding oily wastewater purification capacity. As for electromagnetic microwave absorption, it achieved a strong reflection loss of -41.8 dB, and the effective absorption bandwidth reached 6.86 GHz. Besides, the oil adsorption capacity for trichloromethane reached as high as 93.167 g g-1 with a capacity retention of 95.6% after 5 cycles. Meanwhile, it could act as a gravity-driven separation membrane to continuously separate trichloromethane from a trichloromethane-water mixture with a high flux of 7867.37 L·m-2·h-1, even for surfactant-stabilized water-in-n-heptane emulsions of 3794.94 L·m-2·h-1. Such a strategy might shed some light on the construction of multifunctional aerogels toward broader applications.

Magnetic hollow fibers of covalent organic frameworks (COF) for pollutant degradation and adsorptive removal

The shaping of covalent organic frameworks (COFs) from non-processible powder forms into applicable architectures with additional functionality remains a challenge. Using pre-electrospun polymer fibers as a sacrificial template, herein, we report a green synthesis of an architecture in the form of COF hollow fibers with an inner layer of peroxidase-like iron oxide nanoparticles as a catalytic material. When compared to peroxidase-like pristine iron oxide nanoparticles, these COF hollow fibers demonstrate higher catalytic breakdown of crystal violet due to their peroxidase-like activity via advanced oxidation process. Furthermore, as a potential adsorbent, hollow COF fibers exhibit significantly effective adsorption capacity and removal efficiency of organic solvent and oil from water. Because of their magnetic nature, COF hollow fibers can be easily recovered and have exhibited high recycling stability for both catalytic dye degradation and organic solvent removal from water.

Facile preparation of hydrophobic PPy@Si/PU foam for efficient oil adsorption by photothermal effects

AbstractExploring new oil absorbing materials with high adsorption rate remains a global challenge. Hydrophobic porous materials with photothermal conversion property are an attractive option to address oil spills. Herein, the organosilicon (hydroxyl‐terminal polydimethylsiloxane) was used to modify polyurethane (PU) foam to endow it good hydrophobic and compressible properties. Meanwhile, polypyrrole (PPy) with photothermal effect was introduced to endow PU foam with excellent photothermal properties. The PPy@Si/PU composite foams can reach 77.1 and 49.6°C under the laser and simulated sunlight (with the intensity of 1 kW/m2), respectively. The raised temperature of PPy@Si/PU foam makes it adaptable to reduce the crude oil's viscosity and improve its oil adsorption rate. The maximum oil adsorption rate of PPy@Si/PU foam can obtain 175% and 145% under the laser and simulated sunlight, respectively. Therefore, the PPy@Si/PU foam possesses effective photic‐driving oil adsorption capacity, which has a good prospect to be an efficient oil spills treatment material.

Polystyrene-reduced graphene oxide composite as sorbent for oil removal from an Oil-Water mixture

This study enhanced the adsorptive capacity of polystyrene (PS) by infusing reduced graphene oxide (rGO) nanoparticles obtained from the synthesis of graphene oxide to produce PS-rGO composites via electrospinning method. Physicochemical characterization of as-synthesized rGO and PS-rGO were carried out through scanning electron microscopy, N2 physisorption among others. Oil sorption performance of synthesized rGO in crude oil, vegetable oil, fresh engine oil and used engine oil are 130.96 g/g, 121.77 g/g, 105.01 g/g and 100.56 g/g. Oil sorption capacities of electrospun pure PS in crude oil, vegetable oil, fresh engine oil and used engine oil were 46.32 g/g, 38.54 g/g, 35.14 g/g and 32.57 g/g and those of PS-rGO infused with 4 wt% of rGO were found to be 105.52 g/g, 98.86 g/g, 86.25 g/g and 83.47 g/g for crude oil, vegetable oil, fresh engine oil and used engine oil samples respectively. Pseudo second order (PSO) kinetic model fits the sorption data of the four oil samples on the four composite sorbents produced. Intra-particle diffusion (IPD) model evidently showed that sorption of the four oil samples on the four composite sorbents, occurred in three (3) phases. Composites demonstrate high oil adsorption capacity, and are reusable upto three sorption–desorption cycles.

Fabrication of superhydrophobic all-biomass aerogels with ultralight, elasticity and degradability for efficient oily wastewater treatment

Oily wastewater has seriously threatened the water ecology and human health. Superhydrophobic biomass-based aerogels are ideal candidates to remedy the oily wastewater, but facing challenges for the usage of toxic small molecules crosslinker and the rational construction of elasticity. Herein, we employed the natural non-toxic citral as crosslinker, and then constructed a superhydrophobic chitosan/bamboo cellular fibers aerogel (S-CS/BCF-A) with ultra-light, high elasticity and degradation performances. Wherein the hydrolysis of methyltrichlorosilane produced silicon hydride and hydrogen chloride, enhanced the hydrophobicity of the aerogel surface and partially reduced rigidity of the pore walls, respectively. The S-CS/BCF-A displayed outstanding fatigue durability, which benefited for its lamellar-fiber interweaved structure. In addition, this aerogel could undergo tape-peeling, UV radiation, and organic solvents immersion without superhydrophobic variation, even in seriously abrasing that the surface still maintained high hydrophobicity. The as-made aerogel possessed high oil adsorption capacity (17.95–44.57 g/g), combined with pump-supported device for effectively recovering large-area oil spills (66,348 L·m−2·h−1). Furthermore, the resultant aerogel could efficiently separate the immiscible oil-water mixture and emulsifying wastewater (types of Oil-in-Water and Water-in-Oil emulsions). This work provides a rational design method for constructing the elastic, durable and biodegradable aerogels, used for speedy and economical separation of oil-water mixtures.

Effective strategy for alleviation of oil contamination in marine via the superhydrophobic biochar: Performances, mechanisms and environmental recalcitrance

The performance of layered double hydroxides (LDH)-biochar composite on alleviating oil spill pollution is poorly understood. A superhydrophobic biochar (NCY) was synthesized from the pristine wood chips biochar (WCB) after the surface deposition of NiCo-LDH (NCB) and hydrophobic modification with stearate. The oil removal potential of the designed biochars was investigated via the diesel oil/crude oil adsorption experiments and the environmental recalcitrance evaluation. The compared characterization results revealed that NiCo-LDH was successfully deposited onto biochar matrix via the electrostatic attraction and pore filling effect, which facilitated a special flower-like hierarchical architecture rough surface for biochar and hinder the multi-layer stacking of LDH. Benefit from the constructed hierarchical architecture, the occupancy of oxygen-containing functional groups and hydrophobic modification of stearate, the water contact angle of NCY (156°) was remarkably larger than NCB (117°) and WCB (50.1°), which exhibit a superhydrophobic. The maximum diesel oil sorption capacities of biochars increased from 3.28 g/g in WCB to 5.64 g/g in NCB and 11.6 g/g in NCY, as well as the maximum crude oil sorption capacities of biochars showed a similar trend (WCB: 4.64 g/g, NCB: 8.74 g/g, NCY: 18.6 g/g). Accordingly, NCY showed higher oil adsorption capacity than NCB and WCB mainly due to the enhanced hydrophobic forces and the π-π electron donor-acceptor interaction resulted from lower amount of O-containing functional groups and superhydrophobic surface wettability. Furthermore, the application of LDH remarkably improved the environmental recalcitrance of biochar (resist to the chemical oxidation and thermal decomposition in marine) due to the coating of NiCo-LDH could enhance the bulk stability of biochar and increase the liable carbon content in biochar. This study proved that the application of NiCo-LDH and stearate could be an effective approach for improve the oil pollution remediation capacity and the environmental recalcitrance of biochar.

Biomimetic dendritic‐networks‐inspired oil-water separation fiber membrane based on TBAC and CNC/PVDF porous nanostructures

Inspired by the multi-level structure of trees in nature, using cellulose nanocrystals/polyvinylidene fluoride (CNC/PVDF) fibers as the support layer and CNC/PVDF/organic branched salt (TBAC) fibers as the filtering layer, to construct oil–water separation membrane with tree-like structure. The membrane's surface (nano spherical) and internal (interconnected pores) structures were regulated by phase separation of CNC induced. The high conductivity of TBAC was utilized to construct branched fibers (d = 53.3 nm) on the backbone fibers (d = 1.2 μm). The impact of TBAC on the microstructure, wetting behavior, and oil–water separation performance of membranes was investigated. Note, TBAC concentration was 0.02 mol/L, the membrane exhibits a highly porous dendritic network structure (with porosity of 85 % and pore size of 6.1 nm), and outstanding wetting properties (water contact angle underoil ˃ 150°). This distinctive structure endows membranes with a high oil adsorption capacity (64.1 g/g of engine oil), oil flux (22873 L/m−2h−1 of toluene). Following ten testing cycles, the toluene adsorption capacity remains at 83.1 % of the initial adsorption, while the separation flux of emulsion (5645 L/m−2h−1) remains nearly constant. Overall, successfully fabricating CNC/PVDF/T-0.02 fibers with a tree-like structure provides a novel approach to designing and developing efficient membrane separation materials.

Green preparation of Fe3O4/HA/CS magnetic nanoparticles for oil–water separation

AbstractBACKGROUNDDemulsification using chitosan (CS)‐coated magnetic nanomaterials has garnered significant attention. However, traditional methods for synthesizing chitosan (CS)‐coated magnetic nanomaterials are often contaminated, laborious, and time‐consuming. Moreover, they showed poor demulsification efficiency due to the occupation of free amino groups in CS by crosslinking agents.RESULTSCS‐coated Fe3O4 magnetic nanoparticles (MNPs) were synthesized using humic acid (HA) as a bridge. The Fe3O4/HA/CS MNPs are recyclable demulsifiers for hexadecane‐water microemulsions. The impacts of MNP dosage, separation time, and pH on demulsification efficiency were studied comprehensively. Compared with Fe3O4/HA and Fe3O4/CS MNPs, the demulsification efficiency of the Fe3O4/HA/CS MNPs was superior. The pseudo‐second‐order kinetic model and the Sips isotherm best describe the demulsification process. Combined with the influence factors of demulsification efficiency, the demulsification mechanism involves electrostatic interactions between MNPs and oil microparticles. The maximum adsorption capacity for oil by the Fe3O4/HA/CS MNPs was 91.73 mg g−1.CONCLUSIONThis research presents a new method for connecting CS to MNPs with a high surface positive charge. As synthesized Fe3O4/HA/CS MNPs is expected to serve as highly efficient and recyclable demulsifiers for emulsified oil wastewater. © 2024 Society of Chemical Industry (SCI).

Alkaline solubilization of microalgal protein and its impact on the functional properties of protein extract

Microalgal alternative proteins are increasingly recognized as a sustainable and promising source for future food production. Despite the widespread use of alkaline solubilization in protein extraction, its influence on the functional properties of microalgal protein extracts has received limited attention. This study marks the pioneering effort to assess the impact of alkaline (NaOH) solubilization on both the extraction process and the functional properties of Chlorella vulgaris protein extract (CVPE) obtained through isoelectric precipitation. With the gradual escalation of alkaline concentration from 0 to 0.7 M, there was a notable improvement in protein extraction efficiency, increasing significantly from 6.22 % to 56.23 %. However, elevated NaOH concentrations resulted in protein degradation, as evidenced in SDS-PAGE studies. Alkaline solubilization exhibited a positive impact on various functional properties of CVPE. It enhanced solubility, water absorption capacity, foaming capacity and stability, as well as emulsifying activity and stability. However, there was a slight decrease in oil absorption capacity with increasing NaOH concentration. Notably, the maximum solubility, oil adsorption capacity, foaming capacity, and emulsion activity of CVPE were 2.3-, 1.8-, 2-, and 1.3-fold higher, respectively, than those of commercial soy protein isolate (SPI). This highlights the effectiveness of alkaline solubilization in modifying C. vulgaris protein and emphasizes the high potential of CVPE as a functional food ingredient.