Morphology Of Microspheres Research Articles

Production and characterization of Zn- and Cu-doped Y2O3-Al2O3-SiO2 (YAS) glass microspheres.

Y2O3-Al2O3-SiO2 (YAS) glass microspheres are currently used in radioembolization treatment. However, abscess formation can occur following this treatment. This study aims to endow YAS glass microspheres with antibacterial properties to address the abscesses forming in patients after radioembolization treatment. In this study, undoped YAS glass microspheres and those doped with antibacterial agents zinc (Zn) and/or copper (Cu) were successfully fabricated using a sol-gel derived method. After heat treatment, the microspheres exhibited an amorphous structure. Additionally, the incorporation of Zn and/or Cu dopants did not alter the patterns observed in the X-ray diffraction analysis. Fourier transform infrared spectroscopy analysis detected Si-O-Si, Al-O-Al, and Y-O band vibrations within the structure. The presence of Zn and Cu dopants was confirmed through X-ray photoelectron spectroscopy analysis. Scanning electron microscopy revealed that all samples possessed a regular microsphere morphology, with average particle sizes ranging from 6 to 50 μm. These average particle sizes were further confirmed using a mastersizer. The antibacterial agent-doped YAS glass microspheres show promise in combating infections that occur following radioembolization treatment.

Synthesized and characterization of Ce2(MoO4)2(Mo2O7)/MoO3 nanocomposites with Schiff-base ligand assistance as possible electrode materials for electrochemical energy storage

Transition metal oxides, which can deliver a cooperative impact through electrochemical processes, are now being investigated extensively as potential electrode materials for next-generation storage devices. Ce2(MoO4)2(Mo2O7)/MoO3 composites were created using hydrothermal technique aided by Schiff-base ligands in the low temperature and short time. Synthesis of composites in the presence of different ligands led to design different morphologies such as particles, plates, flower-shaped and spheres. The produced sample functions as an active component of the electrochemical energy storing arrangement, which is included of a KOH electrolyte and a three-electrode cell. Morphology affects both the durability of the compounds in the designed working electrode and the kinetics of the electrochemical process. Although, capacitance of Ce2(MoO4)2(Mo2O7)/MoO3 composites was considered at different morphologies for determining optimal performance. Results show ideal sample prepared in the presence of H2acacmda with microsphere morphology and surface area of 12.83 m2g−1 which demonstrates maximum capacity of 246 mAhg−1.

Controllable preparation of hexanitrostilbene (HNS) microspheres with multi-cavity structure to enhance safety and combustion performance

Controlling the structure to meet the demand for high-energy, low-sensitivity energetic materials in modern military and civilian applications is an effective method. In this study, hexanitrostilbene (HNS) microspheres with a multi-cavity structure were prepared using nitrocellulose (NC) and fluororubber (F2604) as binders via microjet droplet technology. The effects of flow rate, receiving liquid temperature, and suspension concentration on the morphology, particle size, and cavity of the HNS microspheres were investigated. Furthermore, the impact of the multi-cavity structure on the microspheres' specific surface area, dispersibility, thermal properties, safety performance, and combustion performance was studied. Results showed that the multi-cavity HNS microspheres retained the raw materials' crystal structure while exhibiting improved dispersibility, higher activation energy, and shorter ignition delay. Moreover, the multi-cavity structure outperformed the solid structure in terms of specific surface area, safety performance, and combustion performance. This study opens up a new direction for the preparation of multi-structured energetic microspheres.

Fabrication of a novel sensor based on ionic porous polymer microspheres for humidity monitoring

A novel humidity sensor based on ionic porous polymer (IPP) microspheres was prepared in this work. The chemical structure and morphology of IPP microspheres were carefully characterized. The intrinsic hydrophilic ionic units of IPP, –N+R– and Br–, could enhance the adsorption of water molecules and ionic conductivity. The aromatic groups in IPP can adjust its hydrophobicity and ensure stability. Meanwhile, the structure of microspheres provides a favorable space of channels for water molecules transport, which improves the response speed of sensing film further. The impedance of the sensor based on IPP microspheres changed more than three orders of magnitude in the relative humidity (RH) range of 11–95 % RH with a good linearity (R2=0.996) and a fast response speed (6 s/ 27 s). Finally, the mechanism was systematically studied by complex impedance spectrum and theoretical calculation. This study shows a new type of sensor based on ionic porous polymer microspheres, which will pave the way for IPP applications in humidity sensing.

Preparation of nanoporous poly (L-lactic acid) microspheres with controllable morphology via thermally-induced phase separation

This article describes a facile method to prepare nanoporous poly (l-lactic acid) microspheres via a thermally-induced phase separation method with controllable diameters. It was found that the morphology and diameter of PLLA microspheres were easily controlled by adjusting solvent ratio, quenching temperature, and PLLA concentrations. The results revealed that by using a ternary solvent system consisting of 1,3-dioxolane as a good solvent, 2-butanone as mid-solvent, and water as a poor solvent, the diameter of PLLA microspheres can be easily controlled by changing the ratio of 1,3-dioxolane and water. The diameter of PLLA microspheres prepared ranged from 28.8 ± 5.9 μm to 63.8 ± 12.5 μm. Moreover, the evolution of PLLA spherulitic structures grown from polymer solution was confirmed as well through varying solvent ratios and PLLA concentrations. The presence of water as a non-solvent governed the phase separation mechanism of the phase separation process. At the same time, the diameter of the spherulites is affected by the ratio of 1,3-dioxolane controlling the polymer crystallization process in the polymer-rich region. Interestingly, the surface of these spherulites contains nanopores due to the stacking of lamellar crystals of PLLA during polymer crystallization which contributed to its superhydrophobicity and superoleophilicity. Hence, the prepared PLLA spherulites were utilized as PLLA microspheres with nanoporous surfaces for the adsorption and removal of oil in oil/water and oil-in-water emulsion. This facile method provides a novel pathway to prepare nanoporous PLLA microspheres with controllable diameters for eco-friendly oil/water and oil-in-water separation applications.

A novel kind of hollow SiO2@g-C3N4@TiO2 microspheres for rapid removal of dyes and antibiotics in water under sunlight

In this paper, using PVP-modified polystyrene microspheres as template, tetrabutyl titanate (TEOT), tetraethyl orthosilicate (TEOS) and melamine as precursor, we developed a facile one-pot two-step method to preparing a novel kind of mesoporous hollow SiO2@TiO2@g-C3N4 ternary composite microspheres with plush surface, in which highly active black titanium dioxide (TiO2) was formed by simple calcination without further chemical reduction treatment. The structure and morphology of the composite microspheres were detailed characterized for understanding the formation mechanism. Research results indicated that the hollow SiO2 microspheres can promote the formation of oxygen vacancies in TiO2, and the ternary combination narrowed the bandgap width of the black hollow composite microspheres to 1.43 eV, thus endowing it with excellent broad-spectrum catalytic performance for rapid photo-degradation of persistent organic pollutants (POPs) such as dyes and antibiotics in water under sunlight. The removal rates of dyes reached more than 70 %, as well as that of antibiotics more than 50 % within one hour. Finally, a plausible catalytic degradation mechanism was discussed.

Preparation of poly(acrylonitrile-co-styrene) microspheres by reflux precipitation polymerization

Poly(acrylonitrile-co-styrene) microspheres are utilized in several applications due to their superior mechanical properties, excellent chemical stability, and tunable surface modification. In this work, poly(acrylonitrile-co-styrene) microspheres were synthesized in ethyl acetate usingreflux precipitation polymerization. The average particle size and morphology of microspheres were carefully measured to investigate the responding influencing factors. In the growth process of these microspheres, the average particle size of poly(AN-co-St) microspheres changed a little after 180 min. However, the yield of the microspheres continued to increase until 420 min. The properties of the solvents had a significant impact on both the average particle size and the morphology of the poly(AN-co-St) microspheres. The concentrations of the initiator and the cross-linker have minimal effect on the average particle size of poly(AN-co-St) microspheres. By controlling the monomer content at 25 wt%, the yield of these microspheres could reach 82%. The method is straightforward to operate andthe prepared microspheres exhibithigh sphericity and uniformity. As a result, it shows great promise for thepreparation of submicron poly(AN-co-St) microspheres.

The morphologic dependence of MnO2 electrodes in capacitive deionization process

Manganese dioxide (MnO2) materials are one of promising cathode candidates for capacitive deionization (CDI) applications, with their morphology significantly impacting the performance of the electrode material itself. Therefore, this study systematically investigates the structure-performance relationships and the micro-interface ion storage mechanisms of four morphologies of MnO2 (1D nanorods (NNMO), nanowires (NWMO), 3D microspheres (MMO), and hollow urchin-like spheres (HUMO)) in relation to their capacitive deionization performance with typical heavy metal ions (Cd2+) through experimental and theoretical calculations. In terms of pore morphology, capacitance significantly increases with increasing surface curvature of materials, demonstrating a clear pore structure-dependent characteristic. NNMO, with the smallest pore size, has much lower surface capacitance (∼0.15 μF cm−2) than other materials (∼0.33 μF cm−2). As pore size increases, the capacitance distribution difference driven by pore structure size gradually disappears. Regarding surface and interface characteristics, high-energy crystal facets facilitate electron transfer ({310}>{200}≈{211}>{100}) and increase the proportion of surface active sites (Osur), thus promoting CDI absorption kinetics. During the capacitive deionization process, the pore structure (∼77 %) and surface-interface characteristics (∼23 %) exhibit highly coupled features and the driving force for interfacial ion storage among the four materials is in the order of HUMO>MMO>NWMO>NNMO. This work elucidates the morphology-dependent capacitive processes of MnO2 nanomaterials, enhancing the understanding of structure- electrochemical process at the nanoscale but also providing effective guidance for the design and development of practical, high-performance CDI electrode materials.

Synthesis of Co/Ni-Doped mesoporous spinel ferrite microspheres for enhanced Low-Temperature SCR performance

The iron-based catalysts commonly used in the selective catalytic reduction (SCR) process cannot meet the increasingly stringent low-temperature NOx emission targets. In this study, mesoporous microspherical MFe2O4 (M=Co, Ni) spinel ferrite catalysts were synthesized by hydrothermal method and applied to the SCR of ammonia (NH3-SCR) reaction. Compared to Fe3O4, both NiFe2O4 and CoFe2O4 catalysts showed higher SCR catalytic activity at low temperature. The NiFe2O4 catalyst achieved a NO conversion of 95.5 % at 240 °C, while CoFe2O4 exhibited a high NO conversion of 97.6 % at 180 °C and a N2 selectivity of 99.6 %. Various characterization experiments revealed that the introduction of Co and Ni resulted in the formation of a specific mesoporous microsphere morphology in CoFe2O4 and NiFe2O4 catalysts, along with the generation of a large number of oxygen vacancies and acidic sites on the surface. These features facilitate the sequential adsorption and activation of NH3 and NOx species, resulting in excellent catalytic activity at low temperatures. Detailed in situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) measurements showed that on NiFe2O4 the reaction follows the Eley–Rideal (E–R) mechanism, whereas it proceeds through the Langmuir–Hinshelwood (L–H) and Eley–Rideal (E–R) mechanisms on the CoFe2O4 catalyst. This work provides a feasible strategy for enhancing the low-temperature SCR reaction over iron-based catalysts; moreover, the elucidation of the complete reaction mechanism offers a solid foundation for future improvements in denitrification catalysts.

Engineering interleaved large and small Na4MnV(PO4)3@NC microspheres cathode towards high performance sodium ion batteries

The booming consumption of energy storage devices spontaneously accelerates the urgent development of robust cathode materials for sodium-ion batteries (SIBs). In view of this, the sodium superionic conductor Na4MnV(PO4)3 (NMVP), with considerable energy density of 425 Wh kg−1, has become the focus in SIB research. Despite this, the performance of NMVP is substantially compromised by Jahn-Teller distortion of Mn3+ ions in conjunction with inherently limited electronic conductivity. In order to address this limitation, this study introduces a series of N-doped carbon (NC) coated NMVP materials with interleaved large and small microsphere morphology. Of particular note, the optimized NMVP-NC2 shows the most excellent performance, maintaining a capacity of 65.7 mAh g−1 at 5C over 500 cycles. A full cell configuration employing an NMVP-NC2 cathode and a commercial hard carbon (HC) anode manifests commendable circular stability with a capacity of 80.7 mAh g−1 underneath 100 cycles at 1C, with an impressive 95.3 % capacity preservation. This distinctive architecture imparts the materials with a high tap density and a relatively low surface area, which is beneficial to the industrial employment. In addition, density functional theory (DFT) calculations indicate that the NC regulation significantly narrows the NMVP's bandgap and facilitates electron transfer, thereby accelerating electron/ion transport kinetics. The NC coating approach combined with large-scale spray drying tactic in this work offers a clear strategy to industrialize NMVP cathode towards high-performance SIBs.

Spatially confined synthesis of large-sized MoS2 nanosheets in molten KSCN toward efficient hydrogen evolution

Low-temperature KSCN molten salt is a promising technique to synthesize defect-rich MoS2 catalysts for hydrogen evolution reaction (HER). However, owing to the fast ion diffusion rate for rapid crystal growth, the resultant catalysts show a morphology of microsphere, which aggregates from MoS2 nanosheets, to suppress the catalytic performance. In this work, large-sized few-layer MoS2 nanosheets are synthesized via a spatial confinement strategy by adding inert NaCl into the KSCN molten salt. With the NaCl spacer to physically block the long-distance ion diffusion and isolate the chemical reaction, the MoS2 nucleation and subsequent crystal growth could be controlled, guiding the nanosheets to grow along the narrow gap between the NaCl crystals to avoid aggregation. As a result, ultrathin MoS2 nanosheets with a large geometry size are constructed. Profiting from the architecture to expose active sites and boost charge transfer kinetics, the large-sized few-layer MoS2 nanosheets exhibit an impressive HER performance, showing a small η 10 of 160 mV and a low Tafel slope of 53 mV dec−1 with excellent stability. This work provides not only an efficient HER catalyst but also a facile spatial confinement technique to design and synthesize a large spectrum of transition metal sulfides for broad uses.

In situ preparation of aluminum-copper pentafluorobenzoate energy microspheres: Enhancing aluminum combustion properties in composite propellants

Aluminum powder is the main metal fuel in composite propellants, and upgrading the proportion of aluminum powder loaded in solid propellants is currently one of the most effective means of increasing propellant energy. Nonetheless, the substantial disparity in boiling points between the core aluminum particles and the alumina layer enveloping their surfaces often results in reduced reactivity, inadequate combustion, and combustion agglomeration during the combustion process of the aluminum powder. Herein, copper pentafluorobenzoate (CuPF) interfacial layer was established on the surface of aluminum powder through the self-assembly coordination reaction between pentafluorobenzoic acid and copper ions, and Al-CuPF energy microspheres were successfully prepared. A comprehensive examination was carried out to scrutinize the surface morphology, elemental composition, and distribution of the Al-CuPF energy microspheres. Furthermore, meticulous studies were conducted on the ignition and combustion properties of these Al-CuPF energy microspheres under various atmospheric conditions. It was found that the Al-CuPF interfacial layer within the Al-CuPF energy microspheres plays a pivotal role in enhancing ignition initiation and acting as a catalyst to facilitate the more efficient combustion of aluminum powder. Moreover, the combustion behavior of Al-CuPF energy microspheres when integrated into composite propellants has been exhaustively researched. Notably, composite propellants incorporating Al-CuPF energy microspheres exhibit heightened burning temperatures and an increased burning rate. Additionally, the combustion and agglomeration dynamics of Al-CuPF energy microspheres on the propellant burning surface were meticulously documented using a high-speed camera. The findings revealed that Al-CuPF energy microspheres spend a significantly shorter duration on the propellant burning surface and notably mitigate the occurrence of aluminum agglomeration issues thereon. This research contributes fresh insights into the application of innovative aluminum-based fuels within the realm of composite propellants.

Oral alginate microspheres for the efficient site-specific delivery of epidermal growth factor attenuated murine ulcerative colitis via repairing the mucosal barrier

Ulcerative colitis (UC) is a chronic bowel inflammatory disease affecting the colorectum. Epidermal growth factor (EGF) has been demonstrated to be effective to counteract UC. However, there exists the gastrointestinal challenges such as stomach acid, enzyme and bile salts for oral delivery of EGF. Herein, calcium alginate microsphere was prepared by the microfluidic technique to encapsulate EGF. The morphology of EGF-loaded microsphere (MS-EGF) was spherical and its average particle size was 80 ± 23 μm. The encapsulation efficiency of EGF was reaching to 93.8 % ± 1.6 %. In vitro release experiments showed that MS-EGF presented the good pH-sensitive properties, that was, it could effectively resist the gastric acid and small intestinal fluids, and undergone the rapid dissolution in the artificial colon fluid. In vitro cellular experiments demonstrated that the bioactivity of EGF was well preserved by microsphere. Moreover, in vivo murine colitis model showed that MS-EGF presented the obvious colitis alleviation. Furthermore, the colonic morphology of colitis mice was effectively recovered and the tight junction between the gut epithelium was obviously repaired. In conclusion, calcium alginate microsphere might be a promising vehicle of EGF for UC treatment.

Fabrication of crosslinked starch microspheres via water-in-water Pickering emulsion and their application in controlled release of Vitamin C

Green technology for the fabrication of bio-degradable microspheres is exciting and needed. In this study, a new water-in-water Pickering emulsion green technology is proposed for the fabrication of the crosslinked starch microspheres with sodium tripolyphosphate as the crosslinker, polyethylene glycol aqueous solution as the continuous phase (PEG phase) and starch aqueous solution as the dispersed phase (starch phase). The factors that affect the morphology and particle sizes of cross-linked starch microspheres are investigated by laser scanning confocal microscope (LCM) and laser particle size analyzer. The results reveal that the particle sizes of crosslinked starch microspheres are increasing with increased starch concentration. The particle sizes of crosslinked starch microspheres show a first increase and then decrease trend with the increase of the concentration of PEG 20,000 in the PEG phase. The hydrophobic nano silica is used as an emulsifier to form water-in-water Pickering emulsion and shows an obvious effect on the morphology of starch microspheres. When the starch concentration is 20.00 wt%, PEG 20000 concentration is 32.56 wt%, the ratio of starch to PEG phase is 0.20 and the amount of silica is 5.00 wt% of starch, starch microspheres with regular shapes are obtained with the size of about 32.30 ± 0.22 µm. The fabricated cross-linked starch microspheres are non-crystalline and show good water and oil absorption performances. The application of fabricated crosslinked starch microspheres in the adsorption and release of Vitamin C is conducted. The maximum adsorption capacity of crosslinked starch microspheres for Vitamin C reaches 309.9 mg/g. Starch microspheres show a controlled release of Vitamin C in water. This study indicated that crosslinked starch microspheres can be fabricated through a green water-in-water Pickering emulsion technology and may find potential applications in degradable controlled-release microspheres.

Simulation of in vitro embolization effect of drug-loaded microspheres

Drug-loaded microspheres are widely used in transcatheter arterial chemoembolization (TACE). Controlled drug release from drug-loaded microspheres reduces systemic toxicity, thus necessitating the development of microspheres with controlled release properties. In this study, three different sizes of sodium hyaluronate microspheres (SH) were prepared by a one-step solution drying method using 1,4-butanediol diglycidyl ether (BDDE) as a crosslinking agent. The average sizes of the three SH microspheres (small, medium and large) were 410 μm, 550 μm and 750 μm, respectively. The morphology of the small-sized SH microspheres (SS-SH) was solid spherical; the medium-sized SH microspheres (MS-SH) were semi-hollow spherical; and the large-sized SH microspheres (LS-SH) had a bowl with an opening on one side and a cavity inside. A drug-loaded microsphere (DOX@SH) was prepared by immersing SH microspheres in a doxorubicin hydrochloride (DOX) solution. The average size of the three DOX@SH microspheres increased to 607 μm, 876 μm and 1187 μm, respectively. The encapsulation efficiencies of small, medium and large-sized SH microspheres reached 97.09 %, 96.73 % and 74.87 % at 2 h in a 2 mg/mL DOX solution. The maximum drug loadings of the small, medium and large-sized SH microspheres were 0.38, 0.38 and 0.33 mg DOX/mg SH, respectively. All sizes of DOX@SH microspheres could be controlled and sustained to release and reach equilibrium after 48 h. The cumulative release rates of small, medium and large-sized DOX@SH microspheres (SS-DOX@SH, MS-DOX@SH and LS-DOX@SH) at 72 h were 24.3 %, 28.1 % and 33.8 % in a release medium of pH 6.5, respectively. Blood compatibility and cytotoxicity tests demonstrated that SH microspheres exhibit good biocompatibility. The cytotoxicity of DOX@SH microspheres to HepG2 cells and the uptake of DOX in HepG2 cells showed effective anti-tumor activity. Simulated embolization in vitro experiments indicated that the small-sized DOX@SH microspheres had a good embolization effect for 500–800 μm and 300–500 μm blood vessels. These findings indicate that the newly developed DOX@SH microspheres can be used as a promising drug-loaded embolization agent to enhance the treatment of hepatocellular carcinoma.

Effective desensitization of composite materials HMX@PDA by insensitive DAAF: To improve safety performance

The sensitivity of energetic materials to external stimuli (mechanical, flame, etc.) limits their practical application. In order to improve the safety of HMX@PDA composite materials. In this study, HMX/DAAF@PDA composite microspheres with different mass ratios were prepared using a microfluidic self-assembly strategy, and the morphology, size, crystal structure, thermal behavior, flowability and mechanical sensitivity of the sample microspheres were analyzed. The results showed that the addition of DAAF did not change the crystal structure of the composites, and the HMX/DAAF@PDA composite microspheres showed high consistency and repeatability, concentrated particle size distribution, sphericity greater than 0.9 and good flowability. Meanwhile, the impact sensitivity of the sample was increased from 25 J to 50 J (S-3) and the friction sensitivity was increased from 160 N to 216 N. In addition, the ignition experiment and EXPLO5 calculation results show that the addition of insensitive DAAF can reduce the combustion of composite materials, thereby improving the application safety of the composites. This study provides a way for the design and preparation of high-energy insensitive composite explosives.

Sea Urchin-Like NiCo-LDH Hollow Spheres Anchored on 3D Graphene Aerogel for High-Performance Supercapacitors.

To enhance the inherent poor conductivity and low cycling stability of dimetallic layered double hydroxides (LDHs) materials, designing a synergistic effect between EDLC capacitors and pseudocapacitors is an efficient strategy. In this paper, we utilized a solvothermal technique employing Co-glycerate as a precursor to prepare sea urchin-like NiCo-LDH hollow spheres anchored on a 3D graphene aerogel. The unique morphology of these hollow microspheres significantly expand the specific surface area and exposes more active sites, while reducing the volume changes of materials during long-term charging and discharging processes. The 3D graphene aerogel serves as a conductive skeleton, improving the material's electrical conductivity and buffering high current. The sea urchin-like NiCo-LDH hollow spheres anchored on 3D graphene aerogel (H-NiCo-LDH@GA) has a specific surface area of 51 m2 g-1 and the ID/IG value is 1.02. The H-NiCo-LDH@GA demonstrate a significant specific capacitance of 236.8 mAh g-1 at 1 A g-1, with a remarkable capacity retention rate of 63.1 % even at 20 A g-1. Even after 8000 cycles at 10 A g-1, the capacity retention still remains at 96.3 %, presenting excellent cycling stability.

Micron-Sized Thiol-Functional Polysilsesquioxane Microspheres with Open and Interconnected Macropores: Effects of the System Composition on the Porous Structure and Particle Size of the Microspheres.

Control of the porous structure and particle size is essential for improving the properties of polysilsesquioxane (PSQ) microspheres. Herein, using the strategy combining inverse suspension polymerization, two-step sol-gel- and polymerization-induced phase separation processes, micron-sized thiol-containing macroporous PSQ (TMPSQ) microspheres with controllable morphologies, adjustable particle diameters (4.9-17.3 μm), and pore sizes (40-3774 nm) were prepared. The morphology and size of the TMPSQ microspheres were characterized by SEM. The mercury intrusion method was employed to analyze the porous structure of the microspheres. The effects of the composition of the sol-gel disperse phase, the mass ratio of the sol-gel disperse phase to the oil continuous phase (WRW/O), and the Span 80 mass content in the oil continuous phase on the morphology, particle diameter and pore size of the TMPSQ microspheres were investigated. Results indicated that the composition of the sol-gel disperse phase determines the morphology and porous structure of the microspheres, and WRW/O and Span 80 content have remarkable impacts on the morphology and particle size of the microspheres. This study is beneficial to the design and fabrication of functional PSQ microspheres with desired properties and promising application prospects.

Enhancing electrochemical water-splitting efficiency with superaerophobic nickel-coated catalysts on Chinese rice paper

The quest for efficient hydrogen production highlights the need for cost-effective and high-performance catalysts to enhance the electrochemical water-splitting process. A significant challenge in developing self-supporting catalysts lies in the high cost and complex modification of traditional substrates. In this study, we developed catalysts featuring superaerophobic microstructures engineered on microspherical nickel-coated Chinese rice paper (Ni-RP), chosen for its affordability and exceptional ductility. These catalysts, due to their microspherical morphology and textured surface, exhibited significant superaerophobic properties, substantially reducing bubble adhesion. The nickel oxy-hydroxide (NiOxHy) and phosphorus-doped nickel (PNi) catalysts on Ni-RP demonstrated effective roles in oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), achieving overpotentials of 250 mV at 20 mA cm−2 and 87 mV at −10 mA cm−2 in 1 M KOH, respectively. Moreover, a custom water-splitting cell using PNi/Ni-RP and NiOxHy/Ni-RP electrodes reached an impressive average voltage of 1.55 V at 10 mA cm−2, with stable performance over 100 h in 1 M KOH. Our findings present a cost-effective, sustainable, and easily modifiable substrate that utilizes superaerophobic structures to create efficient and durable catalysts for water splitting. This work serves as a compelling example of designing high-performance self-supporting catalysts for electrocatalytic applications.

Postmodification with Polycations Enhances Key Properties of Alginate-Based Multicomponent Microcapsules.

Postmodification of alginate-based microspheres with polyelectrolytes (PEs) is commonly used in the cell encapsulation field to control microsphere stability and permeability. However, little is known about how different applied PEs shape the microsphere morphology and properties, particularly in vivo. Here, we addressed this question using model multicomponent alginate-based microcapsules postmodified with PEs of different charge and structure. We found that the postmodification can enhance or impair the mechanical resistance and biocompatibility of microcapsules implanted into a mouse model, with polycations surprisingly providing the best results. Confocal Raman microscopy and confocal laser scanning microscopy (CLSM) analyses revealed stable interpolyelectrolyte complex layers within the parent microcapsule, hindering the access of higher molar weight PEs into the microcapsule core. All microcapsules showed negative surface zeta potential, indicating that the postmodification PEs get hidden within the microcapsule membrane, which agrees with CLSM data. Human whole blood assay revealed complex behavior of microcapsules regarding their inflammatory and coagulation potential. Importantly, most of the postmodification PEs, including polycations, were found to be benign toward the encapsulated model cells.