Synthesis Of Microspheres Research Articles

Synthesis of nanostructured microspheres of NiCoO2 for photocatalytic dye degradation

Synthesis of nanostructured microspheres of NiCoO2 for photocatalytic dye degradation

Template-free synthesis of hollow microsphere CdS/ZnO heterojunction photocatalysts for photocatalytic hydrogen production

Template-free synthesis of hollow microsphere CdS/ZnO heterojunction photocatalysts for photocatalytic hydrogen production

In-situ synthesis of 3D TiO2 microspheres on Ti mesh to enhance photoelectrochemical water splitting

Much attention has been focused on the fabrication of TiO2 microspheres due to their excellent properties and attractive potential in many fields. Here, undoped 3D hierarchical TiO2 microspheres (TMS) were synthesized in situ on Ti mesh using a hydrothermal method by varying NaOH concentration, reaction time and temperature. The 3D TMS grown along the surface of the woven wires of the Ti meshes, using the metal Ti meshes as a substrate, which resulted in improved conductivity. Meanwhile, the original Ti mesh with the macroporosity (due to the 15 % open area of the mesh) can act as fast proton mass diffusion. As a result, the flexible TMS-Ti photoelectrodes exhibit an excellent current density of 1.63 mA/cm2 at a potential of 1.23 V (vs Ag/AgCl). Therefore, the in situ synthesis of TiO2 microspheres on Ti mesh is highly desirable for flexible devices.

Synthesis of porous Mg2MnO4 spinel microspheres and enhanced lithium storage properties

Porous Mg2MnO4 spinel microspheres were synthesized by a facile solvothermal method. Various techniques such as X-ray powder diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, were used to characterize the phase composition, morphology and electronic structure of materials. The results show that Mg2MnO4 spinel material was obtained at the temperature of 600–800 °C and has a microsphere structure. The microspheres were assembled by nanoparticles, and the particle size increases with the increase of annealing temperature. Analyses of XPS spectra reveal that Mn exists in multiple valence states (+2, +3, +4) in Mg2MnO4 materials, and all the materials are mixed spinel with Mg2+ and Mn2+/3+/4+ ions occupy both tetrahedral and octahedral sites of spinel structure, and the degree of inversion decreases with increasing annealing temperature. Mg2MnO4 microspheres exhibit excellent lithium storage performance, the first discharge specific capacity of M2MO-8 is 835.3 mAh g−1 under a voltage window of 0–3 V and with a current density of 100 mA g−1, and after 100 cycles the discharge capacity of the material is as high as 406.5 mAh g−1. In addition, this material shows high cyclic reversibility. The enhanced lithium storage properties of the material can be attributed to its porous structure, which promote the transport of lithium ions and reduce the damage to the structure caused by the volume change during the charge and discharge process.

Density functional theory guide for copolymerization mechanism between allyl radical with radicalophile: photo-driven radical mediated [3 + 2] cyclization.

The challenge of activating inert allyl monomers for polymerization has persisted, prompting our proposal of the photo-driven radical mediated [3 + 2] cyclization reaction (PRMC). This innovative approach significantly expedites the homopolymerization of multi-allyl monomers, enabling the synthesis of embolic microspheres for hepatocellular carcinoma interventions. PRMC involves allyl monomers to form allylic radicals and then radicals participating in a cycloaddition reaction with unsaturated olefins as radicalophiles to form cyclopentane-based radical products. While extensively studied in the theoretical and experimental homopolymerization, PRMC's application in copolymerization remains unexplored. To address this knowledge gap, we explored the elementary reaction, selecting allyl methyl ether radicals (AMER) and α,β-unsaturated ketones as radicalophiles for copolymerization investigations by density functional theory (DFT) analysis. We quantified energy differences between ground and excited states of reactants, elucidated frontier molecular orbitals, and assessed thermodynamic data for copolymerization feasibility. We also evaluated the electronic properties of reactants, predicting the reactivity of radicalophiles and the interactions of intermolecular reactions. Additionally, we applied transition state theory and interaction/deformation models and conducted a local orbital analysis to comprehensively study excess electron distribution and gyration radius of cyclic radical product. Our findings offer vital insights into PRMC's potential in copolymerization. This research provides a robust theoretical foundation for practical application, enhancing the polymerization field. Based on density functional theory (DFT), the calculations were performed at the M06-2X/6-311 + + G(d,p) level in/by Gaussian 16 package. Subsequently, our analytical results apply time-dependent density-functional theory (TD-DFT) and solvent modeling (SMD). Single-point energy calculations determine the driving force behind the radicals' reaction with radicalophiles. Furthermore, we assessed the electrostatic potential (ESP) of the reactants. The results of the calculations were visualized by the Multiwfn 3.6 and VMD 1.9 programs.

Synthesis of boron-based High-Energy composite microspheres via the Co-Flow microchannel method

Boron-based metastable intermolecular composites (MIC), renowned for their swift energy release and elevated thermal output, exhibit significant promise for utilization in domains such as gunpowder, propellants, and powdered fuel ramjet fuels. The work successfully accomplished the safe and efficient preparation of B/Bi2O3 microunits by utilizing co-flow microchannel technology. The choice of the optimal binder, F2603, for this system was determined by simulation analysis. The practicality of the microchannel platform was then verified using Fluent. SEM analysis demonstrated that an amount of 10 % F2603 resulted in the formation of spherical particles. In terms of physical properties, boron treated with 10 % F2603 exhibits a reduction in its angle of repose from 35° of the raw material to 15°, along with a significant enhancement in hydrophobicity. Furthermore, the MICs lower the reaction temperature of raw boron from 840℃ to 770℃. In the constant volume combustion test, the MIC output pressure increased by 33.3 %. In the constant pressure combustion test, the MIC ignition delay time was reduced from 0.7262 s to 0.5566 s. The structural characteristics of the system decrease the distance for mass and heat transmission across components, resulting in improved overall performance. The study unequivocally demonstrates the efficacy of co-flow microchannel technology in swiftly, effectively, and securely producing energetic molecules. It establishes a solid foundation for future industrial manufacturing.

Synthesis of Cellulose Acetate Butyrate Microspheres as Precursor for Hard Carbon-Based Electrodes in Symmetric Supercapacitors.

Cellulose microspheres have a wide range of applications due to their unique properties and versatility. Various preparation methods have been explored to tailor these microspheres for specific applications. Among these methods, the acetate method using cellulose acetate is well known. However, replacement of the acetate group through the butyrate group significantly extends the variety of morphological properties. In the present work, microspheres based on cellulose acetate butyrate are being developed with modified characteristics in terms of particle size, porosity, surface morphology and the inner structure of the microspheres. While the inner structure of cellulose acetate microspheres is predominantly porous, microspheres prepared from cellulose acetate butyrate are mainly filled or contain several smaller microspheres. Carbon materials from cellulose acetate butyrate microspheres exhibit a high specific surface area of 567 m2 g-1, even without further activation. Activation processes can further increase the specific surface area, accompanied by an adaptation of the pore structure. The prepared carbons show promising results in symmetrical supercapacitors with aqueous 6 M KOH electrolytes. Activated carbons derived from cellulose acetate butyrate microspheres demonstrate an energy density of 12 Wh kg-1 at a power density of 0.9 kW kg-1.

Controllable synthesis and magnetization of Fe3O4 microspheres wrapped with amorphous carbon

A straightforward solvothermal methodology was employed to synthesize [Formula: see text] microspheres and [Formula: see text]@C hybrids, where amorphous carbon encapsulated [Formula: see text] microspheres. This encapsulation was achieved by meticulously controlling the reaction duration and glucose concentrations within the hydrothermal process. Analysis via X-ray diffraction and Raman spectroscopy confirmed that all specimens retained a homogeneous [Formula: see text] phase. Following encapsulation, the [Formula: see text] particles were uniformly distributed across the amorphous carbon spheres, with fine particle sizes in the hybrids measuring less than 20 nm. Magnetic characterization revealed that parameters such as saturation magnetization, remanent magnetization, and coercivity of the [Formula: see text] microspheres could be significantly adjusted by varying the hydrothermal reaction time. Notably, the hybrids exhibited a 5- to 10-fold increase in both coercivity and remanent magnetization when compared to the pristine [Formula: see text] microspheres. Nonetheless, the saturation magnetization of the hybrids reached up to 90% of that observed in bulk [Formula: see text]. These magnetic properties are predominantly influenced by the size effect associated with the nanostructured [Formula: see text].

Stepwise extraction of Fe, Si from copper slag and self-assembly synthesis of microspheres for As(V) removal: Resource transformation and environmental governance

Heavy metal pollution control and industrial solid waste management have always been urgent environmental issues. The management of heavy metal pollution through industrial solid waste may be a solution to both problems. In this paper, copper slag (CS) is used as a base material to separate the iron and silicon with a relatively high percentage of content. The Fe-mSiO2/SA (FSA), a microsphere (Φ = 2–3 mm) adsorbent with specific adsorption capacity for As(Ⅴ), was finally synthesized by “Acid leaching & Alkaline extraction & Template synthesis & Gelatinization”. The optimal adsorption conditions were explored using response surface methodology. FSA has a wide range of pH applicability (3–9) and the maximum adsorption capacity is 140.45 mg/g by theoretical calculation. The adsorption process follows pseudo-second-order kinetic model, which indicates that the adsorption process is a surface homogeneous monolayer adsorption controlled by chemisorption mechanism. The synthesis mechanism of FSA was explored by systematic characterization of FSA, and the mechanism of As(Ⅴ) adsorption was elucidated. The −OH and FeOOH formed stable single-tooth or double-tooth complexes with As(Ⅴ) on the surface of FSA. Moreover, the unique spherical structure of FSA facilitates subsequent solid–liquid separation. This study is in line with the concept of economic applicability and “waste for waste”.

Carbamide-mediated facile sol-gel synthesis of porous flower-like ZnCo2O4 microspheres for high-performance asymmetric coin cell supercapacitors

The design and development of ultrahigh-performance nanomaterials possessing novel characteristics are needed to achieve reliable energy storage performance. To satisfy the needs, diverse electrode materials are explored. Even though carbon-based materials hold high surface area and conductivity, their specific capacitance value fails to deliver high-performance applications. Therefore, pseudocapacitive transition metal oxide is adopted to overcome these issues. Among all Zinc Cobaltite, a binary transition metal oxide is widely explored owing to its fascinating electrochemical properties. As most of the synthesis of these kinds of materials requires the hydro/solvothermal method, herein, we have proposed the concept of a facile sol-gel method to prepare this class of materials by using Carbamide as both structure director and fuel to achieve the porous flower-like Zinc Cobaltite. The prepared material delivers the notable gravimetric specific capacitance of 513.3 F g−1. Owing to its unique morphology and porous structure, ion channelization is feasible, which will enhance the electrochemical reaction. Constructed asymmetric coin cell supercapacitor showed an extraordinary specific capacitance of 106.5 F g−1 and energy density of 56.2 Wh kg−1, demonstrating an impressive ability to retain 89.6 % of its capacitance after 4000 cycles at a current density of 6 A g−1. Due to the remarkable electrochemical behavior, this work can act as a guiding tool for designing efficient and cost-effective energy storage devices that will hold prodigious potential in commercial energy storage applications.

Facile and High-Yield Synthesis of Monodisperse and Heat-Resistant Polymaleimide Microspheres by Self-Stabilized Precipitation Polymerization

Facile and High-Yield Synthesis of Monodisperse and Heat-Resistant Polymaleimide Microspheres by Self-Stabilized Precipitation Polymerization

Core-shell structured Mn3O4@CdIn2S4 microspheres with S-scheme charge transfer route for efficient photocatalytic hydrogen evolution

In this study, core–shell Mn3O4@CdIn2S4 (Mn3O4@CIS) microspheres were prepared via synthesis of Mn3O4 microspheres with Mn-MOF as precursor followed by in-situ growth of CdIn2S4 (CIS) shell. The hydrogen evolution rate of the optimized Mn3O4@CIS was 2.6 mmol·g−1·h−1, which were 11.54-fold and 17.44-fold that of CIS and Mn3O4 alone, respectively. The spherical core–shell structure could broaden the light absorption range and enhance the separation and migration of photogenerated carriers, thereby promoting solar energy utilization. More importantly, experimental and computational results proved that the charge migration followed an S-scheme transfer route in the interface between Mn3O4 and CIS, accumulating photogenerated electrons in the conduction band of CIS for robust photocatalytic hydrogen evolution. This work provided a facile strategy for the design and fabrication of efficient photocatalysts via synchronous morphology and S-scheme heterojunction architecture.

Synthesis and characterization of 3-in-1 multifunctional lipiodol-doped Fe3O4@Poly (diallyl isophthalate) microspheres for arterial embolization, chemotherapy, and imaging

Transcatheter arterial embolization plays a pivotal role in treating various diseases. However, the efficacy of embolization therapy in cancer treatment can be limited by several factors, such as inevitable incomplete or non-target embolization, and the tumor recurrence and metastasis caused by the hypoxic microenvironment. Moreover, it is essential to explore simpler, more economical, and efficient methods for microsphere synthesis. Herein, we achieved one-step photocatalytic synthesis of lipiodol-doped Fe3O4@Poly (diallyl iso-phthalate) multifunctional microspheres (IFeD MS) for arterial embolization, chemotherapy, and imaging. The prepared microspheres are in the shape of dried plums, with a particle size of 100–300 μm. Lipiodol demonstrates a certain degree of chemotherapeutic activity, and the incorporation of Fe3O4 enables the microspheres to exhibit magnetothermal response and magnetic resonance imaging capabilities. Furthermore, the radiopaque characteristics of both agents provide the microspheres with promising potential for computed tomography and digital radiography imaging. The renal embolization experiment in rabbits demonstrated that IFeD MS achieved significant embolization and chemotherapeutic effects. Biocompatibility experiments revealed that this embolic agent did not induce tissue damage or inflammation beyond the treatment area. Additionally, IFeD MS exhibited promising imaging potential. The results of this study imply that the developed multifunctional embolic agent IFeD MS may have significant potential in transforming tumors previously only suitable for palliative cares into resectable radical treatments.

Improved synthesis of metformin hydrochloride-sodium alginate (MH-NaALG) microspheres using ultrasonic spray drying

Metformin Hydrochloride (MH), an orally administered antidiabetic drug from the biguanide family, encounters issues of wide particle size distribution, inefficient dissolution rates and short half-life leading to excess dosage which can result in lactic acidosis. Novel approaches that yield smaller particle size and uniform distribution at higher yields are significant to tackle problems associated with solubility and optimum dosage levels of the administered drugs. In the current research related to microsphere synthesis, a controlled process based on pressure and ultrasonic nozzles for the atomization of liquid, was applied with an objective of optimizing particle size of microspheres of MH in sodium alginate, a biopolymer excipient matrix. The study carried out in spray dryer elucidated parameter optimization using one variable at a time approach by varying important parameters as inlet temperature of air (120°C–150 °C), rate of flow of feed (1.5 mL/min-3 mL/min), aspirator rate (800 rpm–1400 rpm) and polymer content in feed solution (1 g–8 g) using ultrasonic and pressure nozzles for comparison with the target output parameter as particle size and yield. While the particle size at optimum conditions were <10 μm for both types of atomization, ultrasound assisted spray drying exhibited narrower distribution compared to the pressure atomization. Particle characterization performed using SEM, optical microscopy, FTIR, XRD and DSC revealed slight deformation with no chemical interaction and slight decrease in crystalline nature of pure drug. Overall, an improved process based on the use of ultrasound with optimized parameters has been demonstrated for synthesis of MH containing microspheres.

ZIF-8 Template-Assisted Synthesis of Polyimide-Derived Nitrogen-Oxygen Co-doped Porous Carbon Microspheres for Supercapacitors

ZIF-8 Template-Assisted Synthesis of Polyimide-Derived Nitrogen-Oxygen Co-doped Porous Carbon Microspheres for Supercapacitors

V2O5 coral microspheres: High performance electrode material for Li-ion supercapacitor

Energy storage devices forms lifeline for most modern devices. The short life cycle and lower power density of batteries has prompted development of supercapacitors as potential alternatives. Li-ion supercapacitors, is an emerging class of energy storage devices. Natural abundance and availability of variable oxidation states make V2O5 an attractive electrode material. Here, we report synthesis of coral microspheres of V2O5 using low temperature solvothermal technique, as electrode material for Li-ion supercapacitor. The annealing temperature plays a cucial role in formation of microspherical aggregates, dictates their surface area and hence the energy storage performance. Samples annealed at 400 °C showed specific capacitance of ∼360 F/g at current density of 0.5 A/g. Our studies suggest that V2O5 based nanostructures holds significant potential for development of hybrid Li-ion supercapacitors.

Controllable synthesis of uniform flower-shaped covalent organic framework microspheres as absorbent for solid-phase extraction of trace 2,4-dichlorophenol.

Controllable synthesis of micro-flower covalent organic frameworks (MFCOFs) with controllable size, monodisperse, spherical, and beautiful flower shape was realized by using 2,5-diformylfuran (DFF) and p-phenylenediamine (p-PDA) as building blocks at room temperature. High-quality MFCOFs (5 - 7μm) were synthesized by controlling the kind ofsolvent, amounts of monomers, catalyst content, and reaction time. The synthesized MFCOFs possessed uniform mesopores deriving from the intrinsic pores of frameworks and wide-distributed pores belonging to the gap between the petals. The MFCOFs-packed solid-phase extraction (SPE) column shows adsorption capacity ofabout 8.85mgg-1 for 2,4-dichlorophenol (2,4-DCP). The MFCOF-based SPE combined with the HPLC method was established for the determination of 2,4-DCP in environmental water. The linear range of this method is 20-1000ngmL-1 (R2 > 0.9994), and limit of detection (S/N = 3) is 10.9ngmL-1. Spiked recoveries were 94.3-98.5% with relative standard deviations lower than 2.3%.

Synthesis of Microspheres Printed with Metals and Investigation of Their Detection Performance Against Some Metals by ICP-OES

In this study, ion-imprinted polymers were prepared. These polymers can be used for the selective removal of Cu(II) ions from aqueous solutions. To this end, (E)-2-hydroxy-5-((vinylphenyl)diazonyl) benzaldehyde was used as a functional monomer in the synthesis stage of the polymeric adsorbent. Cu(II) imprinted poly[Cu(C15H11N2O2)] microspheres have been synthesised by dispersion polymerisation technique through interaction of the template molecule Cu(II) ion with the functional monomer. The specific surface area of Cu(II) imprinted poly[Cu(C15H11N2O2)] microspheres was 374.26 m2/g. The swelling rate was 80%. The maximum adsorption capacity, the optimum pH and the adsorption equilibrium time were determined to be 153.03 mg/g, in the 8-10 range and 30 min, respectively. The relative selectivity coefficients of the imprinted microspheres were found to be 13.09, 57.88, 44.719 and 35.006 for Cu(II)/Ni(II), Cu(II)/Pb(II), Cu(II)/Zn(II) and Cu(II)/Co(II), respectively. These results showed that the Cu(II)-imprinted microspheres were more selective with respect to Cu(II) ions. Reproducibility studies showed that Cu(II) imprinted poly[Cu(C15H11N2O2)] microspheres can be used repeatedly without significant decrease in adsorption capacity.

Synthesis of Flower-Like CuBi2O4 Microspheres and Its Photocatalytic Activity

In this study, visible-light copper bismuth oxide (CuBi2O4) photocatalyst were synthesized via co-precipitation (CuBi2O4-C) and microwave-assisted methods (CuBi2O4-M). The X-ray powder diffraction (XRD) analysis reveals the presence of pure tetragonal, along with band gaps of 2.9 eV in both samples. The microwave-assisted method produced flower-like CuBi2O4 microspheres, which had a larger BET surface area and demonstrated the highest photocatalytic performance, approximately 83.4 % in the decolorization of malachite green (MG) dye under visible light. Therefore, the research suggested a facile strategy for the fast synthesis of CuBi2O4 microspheres under mild reaction conditions. The use of microwave heat treatment is a faster and more efficient way to photocatalyst materials, while also being cost-effective and energy-saving. HIGHLIGHTS The flower-like CuBi2O4 microspheres synthesized via the microwave-assisted method offer a promising approach for efficient and cost-effective photocatalysis, particularly in the degradation of malachite green dye under visible light. This study highlights the potential of microwave synthesis in enhancing the photocatalytic performance of CuBi2O4 materials GRAPHICAL ABSTRACT

Synthesis and structural design of microspheres comprising cellulose nanofibers and artificial lignin polymer by enzyme-mediated Pickering emulsion templating

An enzyme-mediated Pickering emulsion templating strategy to fabricate spherical microparticles comprising cellulose nanofibers and artificial lignin expands the greater use of renewable, carbon dioxide-fixed wood in green cosmetics.