Distinct Core-shell Structure Research Articles

Construction of photonic crystal structural colors on white polyester fabrics

Recently, it has become a novel technology to obtain structural color on fabric and has become a research hotspot in the textile field. However, the researchers still use fabric dyed with black dye as substrates, which does not meet the requirements of clean dyeing. In this work, we aimed at changing the status quo that most structural color fabrics are designed based on black fabrics. SiO2@PDA microspheres with inorganic microspheres SiO2 as the core and black polydopamine as the shell were successfully prepared. White polyester fabrics were taken as substrates to constructing SiO2@PDA photonic crystal structural colors via vertical deposition self-assembly method (VDSM). The morphology and composition of SiO2@PDA microspheres were investigated. The morphology and optical properties of the resultant structural color fabrics were characterized by FESEM and 3D video microscope. The results showed that SiO2@PDA microspheres have good sphericity, monodispersity, exhibiting and with a distinct core-shell structure formed an ordered colloidal array with vacancies and defects on the polyester fabrics by VSDM, which appeared bright, vivid and low angle-dependent structural colors under the visible light. The different structural colors can be obtained by adjusting the size of the SiO2@PDA microspheres and viewing angle, following the Bragg diffraction law. Notably, SiO2@PDA microspheres with black polydopamine shells have the functionality of absorbing incoherently scattered light and can be used to obtain structural colors directly on white fabric substrates, which significantly simplified the preparation process of structural color fabrics.

Multifunctional Reversible Self-Assembled Structures of Cellulose-Derived Phase-Change Nanocrystals.

Owing to advantageous properties attributed to well-organized structures, multifunctional materials with reversible hierarchical and highly ordered arrangement in solid-state assembled structures have drawn tremendous interest. However, such materials rarely exist. Based on the reversible phase transition of phase-change materials (PCMs), phase-change nanocrystals (C18-UCNCs) are presented herein, which are capable of self-assembling into well-ordered hierarchical structures. C18-UCNCs have a core-shell structure consisting of a cellulose crystalline core that retains the basic structure and a soft shell containing octadecyl chains that allow phase transition. The distinct core-shell structure and phase transition of octadecyl chains allow C18-UCNCs to self-assemble into flaky nano/microstructures. These self-assembled C18-UCNCs exhibit efficient thermal transport and light-to-thermal energy conversion, and thus are promising for thermosensitive imaging. Specifically, flaky self-assembled nano/microstructures with manipulable surface morphology, surface wetting, and optical properties are thermoreversible and show thermally induced self-healing properties. By using phase-change nanocrystals as a novel group of PCMs, reversible self-assembled multifunctional materials can be engineered. This study proposes a promising approach for constructing self-assembled hierarchical structures by using phase-change nanocrystals and thereby significantly expands the application of PCMs.

Microporous Co1−xFex@C nanoparticles: Strong wideband microwave absorbers for reflection loss less than −20 dB

For advanced microwave absorption materials, the bandwidth of reflection loss (RL) ≤ −20 dB is becoming more and more important due to their applications under some extreme occasions where most of the electromagnetic signals must be absorbed. Herein, in-situ carbon-coated Co-Fe-Al precursor nanoparticles (NPs) were prepared by hydrogen plasma metal reaction (HPMR), and then microporous Co1−xFex@C NPs with an average particle size of about 50 nm were successfully prepared by chemical dealloying. They exhibit a distinct core-shell structure with an amorphous carbon shell of approximately 3 nm and a Co1−xFex alloy core containing micropores of 1.1 nm. As the amount of Fe in the microporous Co1−xFex@C NPs increases from 2.1 wt% to 12.0 wt%, the saturation magnetization gradually enlarges from 82.6 to 92.4 emu g−1 whereas the coercive force only decreases slightly. The Co0.98Fe0.02@C sample shows the widest bandwidth (RL ≤ −10 dB) of 11.3 GHz, and surprisingly the bandwidth corresponding to the RL below −20 dB reaches 6.0 GHz, far superior to other Co-based absorbers. Meanwhile, its minimum RL (RLmin) value reaches −102.3 dB with a thickness of 1.8 mm. As the content of Fe increases to 12.0 wt%, the absorption bandwidth (RL ≤ −20 dB) of Co0.88Fe0.12@C sample decreases to 5.7 GHz while its RLmin value strengthens to −133.7 dB. Both the two samples added with Fe exhibit much wider absorption bandwidth (RL ≤ −20 dB) compared with Co@C NPs without Fe addition. The excellent absorption properties are mainly attributed to the facts that microporous morphology promotes the interfacial and dipole polarization, and Fe addition enhances the magnetic resonance. The Co1−xFex@C NPs may pave a new way for designing effective broadband absorbers for RL ≤ −20 dB to meet the high-performance requirements.

Core-Shell poly-(D,l-Lactide-co-Glycolide)-chitosan Nanospheres with simvastatin-doxycycline for periodontal and osseous repair

This study aimed to evaluated the potential of core-shell poly(D,l-lactide-co-glycolide)-chitosan (PLGA-chitosan) nanospheres encapsulating simvastatin (SIM) and doxycycline (DOX) for promoting periodontal and large-sized osseous defects. SIM, and/or DOX were encapsulated in PLGA-chitosan nanospheres using double emulsion technique and were delivered to sites of experimental periodontitis and large-sized mandibular osseous defects of rats for 1–4 weeks. The resultant nanospheres were ~ 200 nm diameter with distinct core-shell structure and released SIM and DOX sustainably for 28 days. DOX and SIM-DOX nanospheres significantly inhibited P. gingivalis and S. sanguinis. In experimental periodontitis sites, SIM-DOX nanospheres significantly down-regulated IL-1b and MMP-8 and significantly reduced bone loss. In mandibular osseous defects, VEGF was up-regulated, and osteogenesis was significantly augmented with SIM nanospheres treatment. In conclusion, core-shell PLGA-chitosan nanospheres released SIM and DOX sustainably. SIM-DOX and SIM nanospheres could be considered to promote the repair of infected periodontal sites and non-infected osseous defects respectively.

Powder interface modification for synthesis of core-shell structured CoCrFeNiTi high entropy alloy composite

Interface design is a critical topic for development of multifunctional materials. In an effort to achieve novel microstructural materials, we synthesized CoCrFeNiTi-TiN high entropy alloy composite with core-shell microstructure using powder metallurgy process. Initially single phase CoCrFeNiTi0.5 powder with BCC crystal structure was obtained using mechanical alloying process. Afterwards alloyed powder was heat treated at 900 °C under partial pressure ratios (PN2/PAr) of 1.00, 0.67, 0.33 and 0.10. During the heat treatment the powders mainly consisted of FCC, CrN and TiN phases. At higher values of PN2/PAr, the CrN and TiN phase was were present throughout the powder. By decreasing the PN2/PAr value, nitride precipitation was confined at the powder interfaces. PN2/PAr = 0.10 was the optimum atmosphere conditions where a distinct core-shell structure was formed. At this condition, TiN made up the shell while rest of the elements formed the core. Finally, core-shell powder was consolidated using spark plasma sintering (SPS) to achieve a bulk with core-shell microstructure. This fabrication method reveals a promising avenue to achieve multifunctional high entropy alloys.

Controlled released of drug from doubled-walled PVA hydrogel/PCL microspheres prepared by single needle electrospraying method

Poly(vinyl alcohol) (PVA) hydrogels have been extensively studied as drug delivery systems. However, due to the high hydrophilicity of PVA, these hydrogels have weak abilities to efficiently load drugs and control the initial burst release. In this study, we present a one-step simple and rapid single needle electrospraying (SNESy) method that combines PVA hydrogels with another biocompatible polymer polycaprolactone (PCL). A distinct core-shell structure was obtained with the PVA hydrogel core and PCL shell after the system was properly set up. The results revealed that the volume ratio between PVA hydrogel and PCL played an important role in determining the particle size and the formation of a spherical structure. The double-walled structure of the microsphere was confirmed by taking the fluorescent images and conducting the ATR-FTIR method. Furthermore, doxorubicin hydrochloride was used as a model drug to evaluate the drug loading capacity and the in vitro release behavior of this PVA hydrogel/PCL microsphere. The results indicated that coating a layer of PCL polymer significantly enhanced the drug loading capacity and reduced the drug initial burst release compared to the single-layer PVA hydrogel nanoparticles, demonstrating these biocompatible double-walled microspheres can be applied as excellent drug delivery carriers.

Development of leak-free phase change material aggregates

This study aims to develop leak-free phase change material (PCM)-aggregates through a two-step pelletization process. Microencapsulated PCM (mPCM) was incorporated into the core of the aggregate during the granulation process and then coated with a PCM-free shell to overcome the PCM leakage. The thermal properties of pellets cured under CO2 and natural air, including their enthalpy and thermal conductivity as well as their thermal stability were measured and compared using differential scanning calorimeter, thermogravimetric analyses and transient plane source method. The effect of both mPCM content and CO2 curing on the strength of the aggregates was also analyzed. The results revealed that mPCM can be used to produce lightweight aggregates with a distinct core-shell structure having an oven-dry bulk density, water absorption and latent heat of about 788 kg/m3, 14% and 18 kJ/kg, respectively. In addition, the shell layer can effectively prevent the leakage of the PCM and can be further densified by CO2 curing. In addition, CO2 curing contributed to the improvement of the overall physical properties and early strength development of the aggregates. The developed leak-free PCM-aggregates would then allow adding PCM into the concrete mix as an inert material and hence suppress the degradation of mechanical strength and high-water demand caused by the direct use of mPCM in concrete.

Phase change microcapsules with lead tungstate shell for gamma radiation shielding and thermal energy storage

Novel microencapsulated phase change materials (MEPCMs) composed of the lead tungstate (PbWO4) shell and paraffin core were designed for shielding of gamma radiation as well as thermal energy storage. Such MEPCMs were prepared via self-assembly methods and in-situ precipitation. The PbWO4 shell with excellent photon attenuation can give the resulting MEPCMs an acceptable gamma radiation shielding capability. The chemical composition and structure of microcapsules samples were studied by X-ray diffractometer (XRD) and Fourier-transform infrared spectroscopy (FTIR). The effects of different core/shell mass ratios on the surface morphology and microstructure of the MEPCMs were determined by scanning electron microscopy (SEM), energy-dispersive spectrometer (EDS), and transmission electronic microscopy (TEM). It was confirmed that the microcapsules exhibit a distinct core-shell structure and a perfect spherical shape. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to present thermal stability and thermal-storage capability of MEPCMs. A high-purity germanium gamma spectrometer to measure the attenuation coefficient of the microcapsules for gamma rays showed that the MECPMs has good γ-rays-shielding property. The multifunction microcapsules in this study have great potential applications for building energy conservation as well as wearable personal protection in nuclear energy engineering.

Micro-sized FeS2@FeSO4 core-shell composite for advanced lithium storage

Core-shell structures with resilient shells and high energy density cores are demonstrated to exhibit good chemical diffusion of Li+, high conductivity and cycling stability. Hence, a simple and novel method has been proposed at the first time to synthesize the micro-sized FeS2@FeSO4 core-shell composite. The cubic FeS2 with a rough surface and a size of 1–2 μm is homogeneously covered by a layer of FeSO4, which is formed via slow oxidation. The distinct core-shell structure not only effectively alleviates the huge volume expansion of FeS2, but also improves the reaction kinetics of the electrode. Therefore, the micro-sized FeS2@FeSO4 core-shell composite displays excellent reversible capacity and stable cycling performance as an anode material for lithium storage. In particular, the composite anode delivers a superior cycling performance of 1171 mAh g−1 and capacity retention of 90.8% after 200 cycles at 0.2 A g−1. Even under a current density of 4 A g−1, the micro-sized FeS2@FeSO4 core-shell composite anode achieves a high rate capacity of 744 mAh g−1. Overall, the micro-sized FeS2@FeSO4 core-shell composite has been demonstrated as an ultrafast charge-discharge electrode material for next-generation LIBs. Furthermore, the simple and environment-friendly method opens a door for preparing other transition metal sulfide composites.

NiCo-LDH nanowires@nanosheets core-shell structure grown on carbon fiber cloth for high performance flexible supercapacitor electrode

In this paper, a facile two-step method was adopted to in-situ develop a flexible electrode with NiCo-LDH nanowires@NiCo-LDH nanosheets core-shell structure on carbon fiber cloth (CFC). The electrochemical properties of the composite materials with different Ni/Co molar ratios nanosheets were systematically studied. It is found that the NiCo-LDH nanowires@Ni2Co1-LDH nanosheets (NiCo@Ni2Co1) composite material achieves a high areal capacitance of 9.67 F/cm2 at 5 mA/cm2 and a good cycling stability (75% capacitance retention after 2000 cycles). The excellent performance benefits from the distinct core-shell structure and the synergistic effect of NiCo-LDH nanosheets and NiCo-LDH nanowires. Moreover, a solid-state flexible asymmetric supercapacitor (ASC) assembled with NiCo@Ni2Co1/CFC as positive electrode and activated carbon on CFC as negative electrode can work stably at a voltage of 1.6 V. This ASC displays a high areal energy density of 298.6 uWh/cm2 at a current density of 1 mA/cm2 and with a corresponding areal power density of 0.80 mW/cm2.

Synthesis and characterization of PNIPAM microgel core–silica shell particles

We developed a simple effective approach to prepare poly(N-isopropylacrylamide-co-acrylamide-co-N,N′-methylenebisacrylamide) (PNIPAM/AM/MBA) microgel core–silica shell particles with narrow particle size distribution via the sol–gel reaction of silica precursor deposited directly on the microgel particle surface in the presence of 3-glycidyloxypropyltrimethoxysilane (GLYMO). MBA was used as the cross-linking agent for the formation of microgel with the cross-linked network structure and GLYMO used as a coupling agent. The morphology of hybrid core–shell particles including the shape, core size, shell thickness and surface roughness was governed by the key components of AM and GLYMO. PNIPAM/AM/MBA microgel core–silica shell particles show desirable spherical shape, distinct core–shell structure and raspberry-like particle morphology. In contrast, PNIPAM/MBA microgel core–silica shell particles formed without resort to AM and GLYMO result in very poor silica encapsulation, thereby leading to undesired particle morphology. Incorporation of AM units into PNIPAM/MBA microgel particles increases the lower critical solution temperature (LCST). Furthermore, encapsulation of PNIPAM/AM/MBA microgel particles by silica does not affect the LCST to an appreciable extent, but it greatly reduces the thermo-sensitivity of the hybrid core–shell particles. Finally, the feasibility of using these PNIPAM-based core–silica shell particles as drug carriers was demonstrated.

Diffusion-controlled complex superconducting transition in (YBa2Cu3O7-δ)0.9/(La2/3Sr1/3MnO3)0.1 core-shell composites

The superconductor (SC)/ferromagnetic (FM) systems have shown tremendous attention due to their amazing phenomena at the SC/FM interfaces such as the inverse proximity effect, triplet superconducting pair generation and the non-dissipation spintronics, which exhibit a great potential on scientific development and applications. To explore these unique characteristics, possible unknown effect and seeking for potential capabilities in bulk SC/FM systems, this study focuses on the bulk composites made of the high-TC superconductor YBa2Cu3O7-δ (YBCO) and the highly spin-polarized La2/3Sr1/3MnO3 (LSMO). The (YBCO)0.9/(LSMO)0.1 composites were annealed at short (Comp_2hr) and longer (Comp_18hr) annealing time. We found that the composites form a distinct core-shell structure. The LSMO grains and the outer layer of YBCO interdiffuse into each other and reconstruct in a way to form off-stoichiometric thin shells. Due to the limited interdiffusion speed, a clear white diffusion-limited-boundary separates the shell and core and protects the pure YBCO phase. This core-shell structure modifies the superconducting behavior to appear complex resistivity and magnetization with temperature such as a second transition due to the tunneling of Cooper pairs at low temperature.

Combining the Photocatalysis and Absorption Properties of Core-Shell Cu-BTC@TiO₂ Microspheres: Highly Efficient Desulfurization of Thiophenic Compounds from Fuel.

A core-shell Cu-benzene-1,3,5-tricarboxylic acid (Cu-BTC)@TiO2 was successfully synthesized for photocatalysis-assisted adsorptive desulfurization to improve adsorptive desulfurization (ADS) performance. Under ultraviolet (UV) light irradiation, the TiO2 shell on the surface of Cu-BTC achieved photocatalytic oxidation of thiophenic S-compounds, and the Cu-BTC core adsorbed the oxidation products (sulfoxides and sulfones). The photocatalyst and adsorbent were combined using a distinct core-shell structure. The morphology and structure of the fabricated Cu-BTC@TiO2 microspheres were verified by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, X-ray powder diffraction, nitrogen adsorption-desorption and X-ray photoelectron spectroscopy analyses. A potential formation mechanism of Cu-BTC@TiO2 is proposed based on complementary experiments. The sulfur removal efficiency of the microspheres was evaluated by selective adsorption of benzothiophene (BT) and dibenzothiophene (DBT) from a model fuel with a sulfur concentration of 1000 ppmw. Within a reaction time of 20 min, the BT and DBT conversion reached 86% and 95%, respectively, and achieved ADS capacities of 63.76 and 59.39 mg/g, respectively. The BT conversion and DBT conversion obtained using Cu-BTC@TiO2 was 6.5 and 4.6 times higher, respectively, than that obtained using Cu-BTC. A desulfurization mechanism was proposed, the interaction between thiophenic sulfur compounds and Cu-BTC@TiO2 microspheres was discussed, and the kinetic behavior was analyzed.

Tunable drug release from nanofibers coated with blank cellulose acetate layers fabricated using tri-axial electrospinning

In this study, novel core-shell nanostructures were fabricated through a modified triaxial electrospinning process. These comprised a drug-protein nanocomposite coated with a thin cellulose acetate (CA) shell. They were generated through the simultaneous treatment of an outer solvent, an unelectrospinnable middle fluid, and an electrospinnable core solution in triaxial electrospinning. SEM and TEM results revealed that the core-shell nanofibers had linear and cylindrical morphologies with a diameter from 0.66 to 0.87 μm, and distinct core-shell structures with a shell thickness from 1.8 to 11.6 nm. The presence of a CA coating eliminated the initial burst release of ibuprofen seen from a monolithic drug-protein composite, and allowed us to precisely manipulate the drug release (for a 90% percentage) over a time period from 23.5 to 43.9 h in a tunable manner. Mathematical relationships between the processing conditions, the nanostructures produced, and their functional performance were elucidated.

Core-Shell Nanofibrous Scaffold Based on Polycaprolactone-Silk Fibroin Emulsion Electrospinning for Tissue Engineering Applications.

The vast domain of regenerative medicine comprises complex interactions between specific cells’ extracellular matrix (ECM) towards intracellular matrix formation, its secretion, and modulation of tissue as a whole. In this domain, engineering scaffold utilizing biomaterials along with cells towards formation of living tissues is of immense importance especially for bridging the existing gap of late; nanostructures are offering promising capability of mechano-biological response needed for tissue regeneration. Materials are selected for scaffold fabrication by considering both the mechanical integrity and bioactivity cues they offer. Herein, polycaprolactone (PCL) (biodegradable polyester) and ‘nature’s wonder’ biopolymer silk fibroin (SF) are explored in judicious combinations of emulsion electrospinning rather than conventional electrospinning of polymer blends. The water in oil (W/O) emulsions’ stability is found to be dependent upon the concentration of SF (aqueous phase) dispersed in the PCL solution (organic continuous phase). The spinnability of the emulsions is more dependent upon the viscosity of the solution, dominated by the molecular weight of PCL and its concentration than the conductivity. The nanofibers exhibited distinct core-shell structure with better cytocompatibility and cellular growth with the incorporation of the silk fibroin biopolymer.

Preparation optimization and protective effect on 60Co-γ radiation damage of Pinus koraiensis pinecone polyphenols microspheres

Here, the chitosan and the glutaraldehyde (GA) were used to encapsulate pinecones polyphenols of Pinus koraiensis (P. koraiensis) by emulsification cross-linking technology. First, the prepared parameters (crosslinking agent amount, stirring speed, crosslinking temperature and emulsifying time) of the pinecones polyphenols microspheres (PPMs) were optimized by the response surface methodology (RSM). When chitosan concentration and crosslinking time were 2% and 80min, respectively, the optimal conditions were 7.91mL of crosslinking agent, stirring speed of 660.98r/min, crosslinking temperature of 41.18°C and emulsifying time of 198.65min. The prepared PPMs embedding rate was 73.57%. The optimized PPM possessed a distinct core-shell structure and uniform spherical distribution with a particle size value of 3.4μm. In addition, they had the excellent sustained-release characteristics in vitro. We also evaluated the radioprotective effects of PPMs against 60Co-γ radiation in vivo. PPMs improved significantly the activity of the antioxidant enzyme SOD and reduce MDA level in the plasma of irradiated mice. Accordingly, PPMs could also significantly enhance the immunomodulation activity by promoting the proliferation of splenocytes and monocyte phagocytosis of irradiated mice. These results suggested that PPMs exert effective protection against radiation-induced injury by improving the antioxidant and immunomodulation activities.

Preparation and Properties of Magnetic Hematite Core/Alumina Shell Nanospheres

Magnetic core/alumina shell (MFeCA) structured nanospheres were obtained from a hematite core/alumina precursor shell (HFeCAP) nanosphere precursor. A uniform alumina layer was coated on the surface of -Fe2O3 by the self-assembly of a stearic acid/alumina isopropoxide complex. Hematite cores of the nanospheres were then reduced under H2/N2 gas flow to produce the MFeCA nanospheres. Transmission electron microscopy images showed that the products possessed a distinct core-shell structure. N2 sorption measurements showed that the uniform accessible pore size was 5.2 nm. The surface area was 140m2/g and pore volume were 0.22 cm3/g. Saturation magnetization values indicated the product had a high degree of magnetization (50.2 emu/g).

Hierarchical NiCo-LDH@NiOOH core-shell heterostructure on carbon fiber cloth as battery-like electrode for supercapacitor

Constructing rational structure and utilizing distinctive components are two important keys to promote the development of high performance supercapacitor. Herein, we adopt a facile two-step method to develop an in-situ heterostructure with NiCo-LDH nanowire as core and NiOOH nanosheets as shell on carbon fiber cloth. The resultant NiCo-LDH@NiOOH electrode exhibites a high specific capacitance of about 2622 F g−1 at 1 A g−1 and good cycling stability (88.5% remain after 10000 cycles). This reinforced electrochemical performance is benefit from the distinct core-shell structure, and takes advantage of the synergetic effect to supply more electrochemical active spots and pathways to accelerate electron and ion transport. Furthermore, the fabricated asymmetric supercapacitor of optimized NiCo-LDH@NiOOH//AC device displays a high energy density of 51.7 Wh kg−1 while the power density is 599 W kg−1 and presents a satisfying cycling performance.

Multifunctional Bi@PPy-PEG Core-Shell Nanohybrids for Dual-Modal Imaging and Photothermal Therapy.

High-performance theranostic nanoagents, which integrate multimodal imaging and photothermal therapy for clinical anticancer treatment, are highly desired. Herein, we report the synthesis and bioapplication of a multifunctional theranostic nanoagent based on polyethylene glycol (PEG)-modified polypyrrole (PPy)-coated bismuth (Bi) nanohybrids (referred to as Bi@PPy-PEG NHs) for X-ray computed tomography/photoacoustic (CT/PA) dual-modal imaging and photothermal therapy (PTT). The obtained Bi@PPy-PEG NHs have a distinct core-shell structure with the metallic Bi nanoparticle as the inner core and the PPy-PEG layer as the shell. The Bi@PPy-PEG NHs show excellent physiological stability and compatibility, without noticeable cytotoxicity. Importantly, the NHs exhibit strong NIR absorbance and remarkable photothermal conversion capability and conversion stability, with the photothermal conversion efficiency as high as ∼46.3%. Thanks to the strong PTT effect, highly effective photothermal ablation on cancer cells has been achieved both in vitro and in vivo. Furthermore, a high-contrast in vitro and in vivo CT/PA dual-modal imaging has been realized, showing great potential to provide comprehensive diagnosis information for antitumor treatment. In particular, the CT enhancement efficiency of the NHs is of ∼14.4 HU mM-1, which is ∼3.7-fold that of clinically used iohexol. Therefore, our work highlights the potential of using such core-shell Bi@PPy-PEG NHs as a versatile theranostic nanoplatform for cancer imaging and therapy.

Degradation of nonylphenol polyethoxylates by functionalized Fe3O4 nanoparticle-immobilized Sphingomonas sp. Y2

In this study, the efficiency of the nonylphenol polyethoxylates (NPEOs)-degrading bacterium Sphingomonas sp. strain Y2 was evaluated, which was immobilized by a novel system composed of polydopamine (PD)-coated Fe3O4 iron nanoparticles (IONPs). The PD-IONPs, with a distinct core-shell structure, relatively uniform size, and high saturation magnetization, were prepared for Y2 immobilization. The performance of Y2 was unaffected by this novel immobilization method, exhibiting 79.5% and 99.9% of NPEOs (500ppm) degradation efficiency at day 1 and 2, respectively. Furthermore, separation and recycling were more readily achieved for immobilized cells as compared to free cells. Immobilized cells retained over 70% of the original degradation activity after 6cycles of utilization. These results suggest that Y2-PD-IONPs can be potentially used for NPEOs-contaminated wastewater bioremediation. CapsuleImmobilization of Sphingomonas sp. Y2 by functionalized PD-IONPs with easy separation, recycling utilization and high efficiency.