Bulk Modification Research Articles

Polyetheretherketone‐hydroxyapatite composite filament: A comparative analysis of the effect of micro and nano hydroxyapatite particles on extrusion and performance

AbstractThe performance of polyether‐ether‐ketone (PEEK) as an orthopedic biomaterial can be improved by bulk modification of PEEK through hydroxyapatite (HA) incorporation. In this context, we have studied the size effect of HA particles (from micro to nano) on the high‐temperature extrusion, physicochemical and biological properties of the extruded PEEK‐HA filaments. Our study showed that incorporation of HA into PEEK up to 5% w/w allows filament formation through single screw extrusion. However, a more significant temperature gradient between the hopper end and nozzle was necessary for the extrusion of nano‐HA incorporated PEEK compared to micro‐HA incorporated PEEK. The micro‐CT revealed a homogeneous dispersion of HA particles within the extruded filaments. The inclusion of nano HA powder (<200 nm) in PEEK (5%w/w) did not alter the mechanical properties of PEEK. When checked in vitro using MG‐63 cells, PnHA exhibited better cytocompatibility, as evidenced by calcein‐AM staining and MTT assay. Cellular expression of vascular endothelial growth factor and alkaline phosphatase was also found to be 2–3 fold higher for PnHA. Further, PnHA was found to be a promoter of angiogenesis when checked by tube formation assay. The results together implied that nano‐HA is more suitable than micro‐HA for improving the essential qualities of PEEK for orthopedic applications.Highlights Incorporation of HA in PEEK improves the performance of PEEK as a biomaterial. PEEK with 5% micro/nano HA can be extruded as PEEK‐HA composite filament. Variation in HA particle size (micro/nano) impacts the performance of composite. PEEK‐HA composite filament has improved angiogenic and osteoconductive properties.

Construction of antibacterial silicone rubber catheter modified with the biomass carbon dots and its properties.

To endow silicone rubber (SR) catheter with antibacterial property, the SR catheter was modified with a new kind of biomass carbon dots (CDs) by the bulk modification to obtabin the SR/CDs catheter. The antimicrobial behavior and biocompatibility of SR/CDs catheter were analyzed by plate counting method, cytotoxicity test and in vivo animal experiments. The results showed that, SR/CDs catheter possessed antimicrobial properties, and the minimum inhibitory concentration of SR/CDs catheter was 20 mg/ml against Escherichia coli (E. coil) and Staphylococcus aureus (S. aureus). The antimicrobial mechanism of SR/CDs was further investigated, and it was found that the SR/CDs induced the production of reactive oxygen species in bacterial cells by disrupting the bacterial membrane through adsorption. In addition, in vivo experiments have shown that SR/CDs catheter owns good biosafety profile and reduces the risk of catheter-associated urinary tract infections by modu-lating inflammatory factors. Meanwhile, SR/CDs catheter can be produced in a simple production process using an extruder, which is expected to be used as a novelty type of catheter in the clinic.&#xD.

Restraining Planar Gliding in Single‐Crystalline LiNi0.9Co0.05Mn0.05O2 Cathodes by Combining Bulk and Surface Modification Strategies

AbstractThe delamination cracking from planar gliding along the (003) facets and anisotropic lattice strain perpendicular to the (003) facets inevitable lead to degradation of Ni‐rich single‐crystal cathode materials, adversely affecting their cyclability. Herein, we rationally design a single‐crystal LiNi0.9Co0.05Mn0.05O2 (SC90) cathode with robust chemo‐mechanical properties, in which coherently grown MgO6 octahedra and BO4 tetrahedra are incorporated into the lattice, and a stabilizing Mg3(BO3)2 layer is concurrently formed on the particle surface. Multiscale in/ex situ characterizations and theoretical calculations indicate that introducing the MgO6 and BO4 units leads to a “pinning effect” within the layered structure. This in turn strongly mitigates mechanical degradation by reducing planar gliding and delamination cracking over extended cycling. Moreover, the Mg3(BO3)2 coating maintains fast lithium diffusion by suppressing parasitic reactions at the cathode|electrolyte interface. The tailored SC90 cathode exhibits a capacity retention of ~88 % after 300 cycles at 5 C rate, significantly outperforming the pristine counterpart (~60 %). Additionally, a pouch‐type full cell with a graphite anode sustains a specific discharge capacity of 177 mAh g−1 after 500 cycles, with 90 % capacity retention. This work highlights the “pining effect” in preventing unfavorable slab sliding and structural deterioration, offering new insights for designing advanced ultrahigh Ni single‐crystal cathodes.

Restraining Planar Gliding in Single-Crystalline LiNi0.9Co0.05Mn0.05O2 Cathodes by Combining Bulk and Surface Modification Strategies.

The delamination cracking from planar gliding along the (003) facets and anisotropic lattice strain perpendicular to the (003) facets inevitable lead to degradation of Ni-rich single-crystal cathode materials, adversely affecting their cyclability. Herein, we rationally design a single-crystal LiNi0.9Co0.05Mn0.05O2 (SC90) cathode with robust chemo-mechanical properties, in which coherently grown MgO6 octahedra and BO4 tetrahedra are incorporated into the lattice, and a stabilizing Mg3(BO3)2 layer is concurrently formed on the particle surface. Multiscale in/ex situ characterizations and theoretical calculations indicate that introducing the MgO6 and BO4 units leads to a "pinning effect" within the layered structure. This in turn strongly mitigates mechanical degradation by reducing planar gliding and delamination cracking over extended cycling. Moreover, the Mg3(BO3)2 coating maintains fast lithium diffusion by suppressing parasitic reactions at the cathode|electrolyte interface. The tailored SC90 cathode exhibits a capacity retention of ~88 % after 300 cycles at 5 C rate, significantly outperforming the pristine counterpart (~60 %). Additionally, a pouch-type full cell with a graphite anode sustains a specific discharge capacity of 177 mAh g-1 after 500 cycles, with 90 % capacity retention. This work highlights the "pining effect" in preventing unfavorable slab sliding and structural deterioration, offering new insights for designing advanced ultrahigh Ni single-crystal cathodes.

Robust, Antifouling, and Hydrophilic Particle-Based Double-Network Hydrogel-PVDF Interpenetrating Microfiltration Membrane.

Poly(vinylidene fluoride) (PVDF) membranes with highly hydrophilic and antifouling properties are desirable for oily wastewater treatment. Herein, we report (1) a strategy of bulk modification of PVDF by in situ integration of PVDF and a particle-based double-network (PDN) hydrogel, poly-2-acrylamido-2-methylpropanesulfonate/polyacrylamide (PAMPS/PAAm), via a strong PDN and PVDF interpenetrating polymer network (PDN-PVDF IPN) to obtain a PVDF/PDN solution and (2) the subsequent casting of it into a microfiltration membrane via spray-assisted non-solvent-induced phase separation (SANIPS). The IPN structure modulates the surface segregation behavior of the highly hydrophilic and robust PDN hydrogel in the process of SANIPS, endowing the resulting PVDF/PDN membrane with excellent bulk mechanical properties and much enhanced wettability and thereby high oil/water emulsion separation efficiency and antifouling performance. Moreover, the PVDF/PDN membrane presented good chemical stability upon soaking in strongly acidic and alkaline solutions for an extensive time. Our work expands the research in phase-inversion-based antifouling oil/water separation materials.

One-Pot Fabrication of Highly Flexible Fluorine-Free Lubricant-Infused Poly(vinyl alcohol) Films with Superior Antifouling Properties.

In clinical settings, biofluid-contacting devices can suffer from biofouling, leading to thrombus formation and bacterial biofilm buildup, which impair device function and pose health risks. Traditional antifouling methods, including the use of hydrophilic polymers and heparin coatings, often suffer from instability and reduced bioactivity over time. Lubricant-infused surfaces (LIS) have emerged as a promising alternative due to their long-term stability and broad-spectrum repellency. However, current LIS technologies typically involve complex, multistep processes that restrict their application to surface layers, potentially compromising performance under mechanical stress. This study introduces a novel method for bulk modification of poly(vinyl alcohol) (PVA) films, creating flexible lubricant-infused PVA membranes with superior antifouling properties. These films are fabricated by cross-linking the PVA chains using n-propyltrichlorosilane (n-PTCS) and subsequent infusion with silicone oil as a lubricant. The modified PVA films significantly prevent bacterial adhesion and prolong blood and plasma clot formation. Additionally, these films exhibit enhanced mechanical properties, particularly in elasticity and flexibility compared to unmodified PVA films. The developed technique provides a straightforward method for creating flexible, super-repellent biointerfaces with the potential to prevent blood adhesion and bacterial biofilm formation, which are common complications associated with biofluid-contacting devices and medical implants.

Chemical Resistance of Modified Wood Veneers in Sustainable Load Bearing Elements.

In the pursuit of sustainable engineering solutions, material selection is increasingly directed toward resources that offer functional efficacy, economic feasibility, and minimal environmental impact. To replace environmentally damaging materials like aluminum with more sustainable alternatives like wood-based materials, it is essential to improve the durability and longevity of wood. This study explores the potential suitability of modified veneers as an outer protective layer for unmodified wooden load-bearing elements, providing a cost-effective and resource-efficient alternative to bulk modification. Unmodified, acetylated, furfurylated, and physically densified birch rotary-cut wood veneers were exposed to liquid chemical reagents (acids, base, solvents, and water) and characterized thereafter in tensile tests. The chemical resistance was evaluated based on the deterioration of tensile strength. Additionally, infinite focus microscopy, infrared spectroscopy, and contact angle measurements were performed to track morphological and chemical changes in the veneers. The results demonstrated that acetylation and furfurylation significantly enhanced chemical resistance against the tested reagents.

Near-Surfaces and Bulk Modification of Silicone Rubber under UV- and Vacuum UV-Irradiation Using Excimer and Hg Lamps.

The surface properties of silicone rubber can be modified by irradiation with light from the vacuum ultraviolet (VUV) spectral range of less than 200 nm. After VUV-irradiation at 185 nm with a low-pressure mercury (Hg) lamp, a reduction in residual-dust-coverage (PA fibers) of up to 80% was found. At the same time, the long wavelength UV-radiation at 254 nm of the Hg lamp causes a reduction in the optical transmission properties of the silicone bulk. The near-surface and bulk modification of optically highly transparent silicone rubber was analyzed using XPS, ATR, transmission measurements, and investigations into the reduction of the residual-dust-coverage. A comparison was made between a Hg lamp and an excimer lamp at 172 nm. The results provide valuable information for selecting the appropriate irradiation source, depending on the desired spectral range for a given application. The results indicate that excimer lamps should be preferred for optical applications in the UV-spectral range, while Hg lamps are equally suitable for applications in the visible spectral range despite low transmission losses of less than 0.5%. The irradiation dose data were obtained using a ray tracing simulation as part of these investigations to overcome limitations of UV-sensors, such as their accelerated aging and angular dependence.

Mg bulk and surface modification on Ni/Y2Ti2O7 catalyst for dry reforming of methane

Dry reforming of methane (DRM) can simultaneously convert two greenhouse gases, CH4 and CO2, into high value-added synthetic gas, which can effectively alleviate the energy crisis and optimize the human ecological environment. In this work, the effect of Mg addition method on the activity of the Y2Ti2O7 pyrochlore supported Ni catalysts was investigated in DRM. The H2-TPR and XPS results showed that Mg modification enhanced the interaction between Ni and Y2Ti2O7 pyrochlore support. Thus, much smaller Ni grains with better thermal stability could be achieved on the Mg doped Ni/Y2Ti2O7 catalyst, as evidenced by the XRD, H2-TPD and TEM results. CO2-assistant CH4-TPSR demonstrated that Mg surface modification can facilitate the reaction between the activated CO2∗ and the H∗ produced by CH4 dissociation. Mg incorporation increased the basic site of the Ni/Y2Ti2O7 catalyst, as evidenced by CO2-TPD-MS results, which was conducive to the adsorption and activation of CO2 to promote the removal of coke deposition. Consequently, Ni/Y1·5Mg0·5Ti2O7 and Ni–MgO/Y2Ti2O7 catalysts exhibit higher stability and more potent coke resistance than the unmodified Ni/Y2Ti2O7 sample. It is concluded that higher Ni0 dispersion and more mobile active oxygen species are the main reasons for the improvement of activity and coke resistance of the Ni/Y2Ti2O7 catalysts. In addition, in situ DRIFTS results confirmed that CO2 activation of all catalysts followed the formate intermediate species path.

Synergistic Passivation of Bulk and Interfacial Defects Improves Efficiency and Stability of Inverted Perovskite Solar Cells

Defects both in bulk and at the interfaces serve as charge trapping sites for nonradiative recombination and as ion migration pathways, resulting in degradation of perovskite solar cell efficiency and stability. In this work, a strategy for simultaneous passivation of both bulk and interfacial defects is reported. For bulk passivation polystyrene (PS) is used as an additive in the perovskite precursor which reduces the structural defects by forming larger defect‐free grains. While the F‐PEAI cation is used to passivate the interfacial defects, present at both perovskite HTL/ETL interfaces. Furthermore, by conducting control measurements with just bulk modification (PS), just interface modification (F‐PEAI), and a combination of both, the role of individual defect passivation strategies is decoupled. As a result of simultaneous bulk as well as interfacial passivation, the modified perovskite solar cell shows the highest efficiency of 22.32% with a high Voc of 1.14 V and fill factor of 80%. Moreover, the cells have excellent stability retaining 92% and 99% of their initial efficiency after 1008 h and 560 h under ISOS‐ D1 and D2 storage conditions. These results highlight the importance of simultaneous bulk and interfacial passivation for improving solar cell efficiency and stability.

Microfluidic capillary platform with hydrophilic PDMS for point-of-care immunoassays

Point-of-care (PoC) devices offer the possibility of fast and easy to use testing platforms. Self-driven capillary devices are particularly interesting because they can function without external pumps. Microfluidic devices often rely on polydimethylsiloxane (PDMS) prototyping; however, for self-driven microfluidics, its hydrophobic nature makes its use challenging. Bulk modification of PDMS through copolymers with hydrophilic moieties could be a practical solution because the copolymer is added prior to PDMS baking in a single-step process. In this work, a PDMS bulk modification with dimethylsiloxane-(60–70 % ethylene oxide) block copolymer was used to render PDMS hydrophilic. The addition of 1 % (w/w) copolymer resulted in a hydrophilic PDMS which was then used to fabricate the capillary devices. The microfluidic design included a serpentine channel with reagent entry points connected to a capillary pump and was closed by a membrane layer with conical shaped reservoirs. The reservoirs were designed to allow the sequential entry of the solutions and the device sealing and robustness were improved through PMMA frames with integrated magnets. A proof-of-concept was performed with food colouring demonstrating the capability of the device to flow the solutions sequentially. Finally, an immunoassay to detect the presence of Infliximab, a therapeutic antibody for chronic inflammatory diseases, was used to demonstrate the functionality of the capillary device. The versatility of the device was also shown by performing a fluorescent indirect immunoassay and a colorimetric indirect-ELISA for the detection of Infliximab with both approaches detecting Infliximab in the clinical range of interest (between 3 and 7 μg/mL).

Simultaneous bulk and surface modifications of g-C3N4 via supercritical CO2-assisted post-treatment towards enhanced photocatalytic activity

A high-temperature supercritical CO2 (ScCO2)-assisted post-treatment strategy is developed to simultaneously modify the bulk and surface structures of graphitic carbon nitride (g-C3N4) using ScCO2 as penetrant and a small amount of methanol/acetonitrile mixture as modifiers. Specifically, the product of modified g-C3N4 is obtained through the post-treatment of pristine g-C3N4 in a homogeneous ScCO2/methanol/acetonitrile system, continuously heating to reach a target temperature (330 °C, 15.2 MPa) without a residence time. With the assistance of ScCO2, organic molecules penetrate the interlayers of g-C3N4 and subsequently modify the in-plane structure of g-C3N4. Methanol induces the partial transformation of g-C3N4 into a carbon nitride with a poly(heptazine imide)-like structure and with abundant methyl and hydroxyl groups. Simultaneously, acetonitrile polymerizes into 2,4,6-trimethyl-1,3,5-triazine, which is then covalently grafted onto the surface of modified g-C3N4. Remarkably, the entire post-treatment process is completed within 5 min, achieving a final product yield of 92.3 %. The modified g-C3N4 photocatalyst achieves an H2-evolution rate of 2126.1 μmol·h−1·g−1 and a CO2-to-CO conversion rate of 874.1 µmol·h−1·g−1. This work provides a green, efficient, high-yield, and scalable strategy for preparing layered and porous non-metallic photocatalysts using supercritical fluids technology.

Electrochemically Intercalated Ti3C2 MXene Bulk for Expanding Interlayer Spacing and Enhancing Supercapacitor Performance.

Tuning the interlayer spacing of 2D MXenes bulk mainly focuses on hydrothermal intercalation, physiotherapy intercalation, and ion exchange intercalation. Nevertheless, the feasibility of electrochemical intercalation technology for expanding the interlayer spacing of Ti3C2 MXene bulk is not yet clear, and further research is required to advance it. Here, we employed an electrochemical intercalation technology to successfully embed metal cations (K+ and Na+) into the interlayer structure of Ti3C2 MXene bulk, expanding the interlayer spacing from ∼10.50 to ∼13.10 Å by K+ intercalation, which can broaden electron/ion transport channels and enhance supercapacitor performance. Compared to the pristine Ti3C2 MXene bulk, the specific capacitance value increased by a factor of 2.8. Moreover, the intercalated MXene also exhibits excellent rate capability, with an increase from 47.32 to 70.20%. This work opens up a new path for the modification of Ti3C2 MXene bulk.

Rapid and eco-friendly ultrasonic exfoliation of transition metal dichalcogenides supported on sonogel-nanocarbon black: A non-precious electrocatalyst for hydrogen evolution reaction

Recently, there has been growing interest in replacing expensive platinum-based catalysts with cost-effective non-precious metal alternatives for water electrolysis aimed at hydrogen production. This study introduces an innovative, green, and cost-effective strategy for the development of non-precious electrocatalysts by leveraging sodium alginate-mediated ultrasonic exfoliation to produce transition metal dichalcogenide (TMD) nanosheets. These nanosheets are supported on Sonogel-Carbon electrodes (SGC), providing a novel conductive base for HER catalysis. Using a diverse array of TMD materials, including MoS2, MoSe2, WS2, and WSe2, we assess their catalytic activity towards HER. The study demonstrates significantly enhanced HER performance through bulk modification of the electrodes with nanocarbon black (SGC-CB). This enhancement is primarily due to the synergistic effects of improved electron transfer and increased active site availability, facilitated by the unique structural properties of the exfoliated TMD nanosheets and the conductive Sonogel-Carbon substrate. Notably, the optimized MoSe2NS-SGC-CB configuration achieves an exceptional overpotential of 240 mV at a current density of 10 mA/cm2, surpassing conventional bulk catalysts and highlighting the potential of sodium alginate as a viable dispersing agent for the large-scale production of TMD nanosheets. The operational stability and cost-effectiveness of this electrocatalyst, combined with its environmental friendliness, mark a significant step forward in the pursuit of sustainable hydrogen fuel production technologies.

Chiral Bulk Solitons in Photonic Graphene with Decorated Boundaries

AbstractA chiral bulk soliton in a nonlinear photonic lattice with decorated boundaries, presenting a novel approach to manipulate photonic transport without extensive bulk modifications is proposed. Unlike traditional methods that rely on topological edge and corner modes, this strategy leverages the robust chiral propagation of bulk modes. By introducing nonlinearity into the system, a stable bulk soliton, akin to the topological valley Hall effects is found. The chiral bulk soliton exhibits remarkable stability; the energy does not decay even after a long‐distance propagation; and the corresponding Fourier spectrum confirms the absence of inter‐valley scattering indicating a valley‐locking property. The findings not only contribute to the fundamental understanding of nonlinear photonic systems but also hold significant practical implications for the design and optimization of photonic devices.

Elucidating the origin of laser induced nonlinearities in propagation inside transparent medias: A comparative numerical study of silicon and fused silica

Abstract The creation of localized bulk modification using femtosecond pulses inside semiconductors like silicon (Si) is quite challenging whereas it is not difficult to achieve it for dielectric material like fused silica (FS). So, this report addresses the fundamental origin of this issue. By taking simple numerical approach, it has been found that in FS we can deliver stronger fluence due to self-focusing on higher power level as compared to Si. The origin for the above lies on the spatial-temporal pulse-splitting behavior which is dominant in case of FS at the focus, whereas for Si it is only effective after focus. We have also considered the influence of plasma and Kerr terms to elucidate the reason behind such nonlinearities. For FS case, omission of Kerr term dominates whereas for Si the influence of each term does not significantly create self-focusing like FS under a similar focusing condition. This study could make an important guideline for researchers to understand the complexity of laser-matter interaction in transparent materials specifically being studied by many laser processing industries.

PVA-based formulations as a design-technology platform for orally disintegrating film matrices

In the majority of pharmaceutical applications, polymers are employed extensively in a diverse range of pharmaceutical products, serving as indispensable components of contemporary solid oral dosage forms. A comprehensive understanding of the properties of polymers and selection the appropriate methods of characterization is essential for the design and development of novel drug delivery systems and manufacturing processes. Orally disintegrating film (ODF) formulations are considered to be a potential substitute to traditional oral dosage forms and an alternative method of drug administration for children and uncooperative adult patients, including those with swallowing difficulties. A multitude of pharmaceutical formulations with varying mechanical and biopharmaceutical properties have emerged from the modification of the original polymeric bulk. Here we propose different formulation approaches, i.e. solvent casting (SC), 3D printing (3DP), electrospinning (ES), and lyophilization (LP) that enabled us to adjust the disintegration time and the release profile of poorly water soluble haloperidol (HAL, BCS class II) from PVA (polyvinyl alcohol) based polymer films while maintaining similar hydrogel composition. In this study, the solubility of haloperidol in aqueous solution was improved by the addition of lactic acid. The prepared films were evaluated for their morphology (SEM, micro-CT), physicochemical and biopharmaceutical properties. TMDSC, TGA and PXRD were employed for extensive thermal and structural analysis of fabricated materials and their stability. These results allowed us to establish correlations between preparation technology, structural characteristics and properties of PVA films and to adapt the suitable manufacturing technique of the ODFs to achieve appropriate HAL dissolution behaviour.

A green bulk modification for imparting a green VIPS membrane with antifouling properties

BackgroundMembrane preparation and membrane modification processes have long involved the use of toxic solvents. The present work proposes to only use envrionmentally-friendly solvents for both the fabrication and the surface modification of hydrophobic microfiltration membranes. In addition, coating processes for membrane modification are essentially surface modification processes. However, spray-coating may be a suitable method for both surface and bulk modification. MethodsAfter dissolving poly(vinylidene fluoride) in dimethylsulfoxide, membranes were formed by the vapor-induced phase separation process, and then modified using an aqeous solution of an amphiphilic copolymer containing poly(ethylene glycol) methyl ether methacrylate units. Then, a variety of physicochemical techniques were employed to characterize the membrane structure and prove the effectiveness of the surface/bulk modification. Antifouling tests in static and dynamic conditions were conducted. Significant findingsIt is possible to reduce the water contact angle of the top surface of the membrane from 135° to 0° and that of the bottom surface from 126° to 0° within <10 s, indicating successful hydrophilization of the membrane on the one hand, and top-to-bottom modification, despite solely exposing the top surface to the spray, on the other hand. This conclusion was confirmed by deidcated surface chemistry analyses. Besides, the membranes maintained their original highly porous and symmetric structure with light effects on surface porosity and pore size following the spray-coating process. The drasting improvement of hydrophilicity resulted in effective mitigation of fibrinogen adsorption (reduced by 85 %) and Escherichia coli adhesion (reduced by 86 %). Fouling during cyclic filtration involving a bacterial suspension was also effectively reduced with a flux recovery ratio of 53 % (against 37 % for a commercial hydrophilic membrane) and an irreversible flux decline ratio of 47 % (against 63 % for a commercial hydrophilic membrane) in the conditions of the test.

Gradient doping–induced triphasic intergrowth hexacyanoferrate cathode for high-performance sodium-ion batteries

As a high-capacity, high-voltage, and low-cost cathode material for sodium-ion batteries (SIBs), Na/Mn-based hexacyanoferrates (NaxMn[Fe(CN)6]1−y·□y·nH2O) typically exhibit poor structural reversibility and interfacial stability during cycling. In this study, we report the in-situ construction of a triphasic intergrowth Na/Mn/Zn-based hexacyanoferrate (mcr-Zn0.2Mn0.8) with concentration-gradient Zn distribution by an anion-controlled fractional precipitation route. Density functional theory calculations verify that the unique heterostructure arises from the different binding energies between cations and anions. A small amount of Zn2+ doping in the inner cubic/monoclinic phases enhances their structural reversibility during cycling by impeding lattice deformation induced by the Jahn–Teller effect of Mn3+. Meanwhile, the rhombohedral Zn-based hexacyanoferrate epitaxially grown on the surface diminishes the particle size of mcr-Zn0.2Mn0.8 resulting in short Na+ diffusion distance, and provides interface protection that suppresses detrimental electrolyte decomposition. Consequently, mcr-Zn0.2Mn0.8 exhibits a high discharge capacity of 121.1 mAh/g at 15 mA g−1, improved cycling stability at 750 mA g−1 with a capacity retention of 65.0 % after 2000 cycles, and enhanced rate capability with a discharge capacity of 71.4 mAh/g at 6000 mA g−1. The successful implementation of simultaneous surface and bulk modifications through a one-step reaction opens new possibilities for developing high-performance hexacyanoferrate cathode materials for SIBs.

Investigation of physical, thermal and morphological properties of CuCl2 modified polyurethane sponges

There are many types of polyurethane sponge (PUS), depending on properties such as hardness, flexibility and surface texture. The fact that it can be produced in any shape and size has given it very wide range of applications. Surface modification is one of the most commonly used methods to improve the performance of PUS. Here, inspired by metal coordination polymers, a simpler and faster method for surface modification of PUS with metal ions compared to bulk modification was proposed. In the case of copper, which is often used for PUS modification, the change in the basic properties sought in different applications as a function of the concentration of the modifier was investigated. Samples prepared by immersing sponges in solutions of copper chloride salt were subjected to physical, thermal and morphological analyses. Due to the modification, the coordination bonds between CuCl2 and polyurethane were revealed by XPS and FTIR. SEM and EDS studies of the PUS revealed both closed and open cells. DSC and TGA analysis showed that the obtained product had better thermal stability than the unmodified product. When the PUS was modified with 0.5 Cu, the water contact angle increased from 101.32° to 135.01° and hydrophobic properties were imparted to all pore surfaces, and the desired properties such as porosity, density could be adjusted. Furthermore, it is envisaged that the surface, mechanical and thermal properties will make it suitable for use in a range of practical applications such as medical and environmental.