Dispersion Of Nanoparticles Research Articles

Ultrastructural Perspectives on the Biology and Taphonomy of Tonian Microfossils From the Draken Formation, Spitsbergen.

Silicified peritidal carbonates of the Tonian Draken Formation, Spitsbergen, contain highly diverse and well-preserved microfossil assemblages dominated by filamentous microbial mats, but also including diverse benthic and/or allochthonous (possibly planktonic) microorganisms. Here, we characterize eight morphospecies in focused ion beam (FIB) ultrathin sections using transmission electron microscopy (TEM) and X-ray absorption near-edge structure (XANES) spectromicroscopy. Raman and XANES spectroscopies show the highly aromatic molecular structure of preserved organic matter. Despite this apparently poor molecular preservation, nano-quartz crystallization allowed for the preservation of various ultrastructures distinguished in TEM. In some filamentous microfossils (Siphonophycus) as well as in all cyanobacterial coccoids, extracellular polysaccharide sheaths appear as bands of dispersed organic nanoparticles. Synodophycus microfossils, made up of pluricellular colonies of coccoids, contain organic walls similar to the F-layers of pleurocapsalean cyanobacteria. In some fossils, internal content occurs as particulate organic matter, forming dense networks throughout ghosts of the intracellular space (e.g., in Salome svalbardensis filaments), or scarce granules (in some Chroococcales). In some chroococcalean microfossils (Gloeodiniopsis mikros, and also possibly Polybessurus), we find layered internal contents that are more continuous than nanoparticulate bands defining the sheaths, and with a shape that can be contracted, folded, or invaginated. We interpret these internal layers as the remains of cell envelope substructures and/or photosynthetic membranes thickened by additional cellular material. Some Myxococccoides show a thick (up to ~ 0.9 μm) wall ultrastructure displaying organic pillars that is best reconciled with a eukaryotic affinity. Finally, a large spheroid with ruptured wall, of uncertain affinity, displays a bi-layered envelope. Altogether, our nanoscale investigations provide unprecedented insights into the taphonomy and taxonomy of this well-preserved assemblage, which can help to assess the nature of organic microstructures in older rocks.

Deep learning-assisted morphological segmentation for effective particle area estimation and prediction of interfacial properties in polymer composites.

The link between the macroscopic properties of polymer nanocomposites and the underlying microstructural features necessitates an understanding of nanoparticle dispersion. The dispersion of nanoparticles introduces variability, potentially leading to clustering and localized accumulation of nanoparticles. This non-uniform dispersion impacts the accuracy of predictive models. In response to this challenge, this study developed an automated and precise technique for particle recognition and detailed mapping of particle positions in scanning electron microscopy (SEM) micrographs. This was achieved by integrating deep convolutional neural networks with advanced image processing techniques. Following particle detection, two dispersion factors were introduced, namely size uniformity and supercritical clustering, to quantify the impact of particle dispersion on properties. These factors, estimated using the computer vision technique, were subsequently used to calculate the effective load-bearing area influenced by the particles. An adapted micromechanical model was then employed to quantify the interfacial strength and thickness of the nanocomposites. This approach enabled the establishment of a correlation between dispersion characteristics and interfacial properties by integrating experimental data, relevant micromechanical models, and quantified dispersion factors. The proposed systematic procedure demonstrates considerable promise in utilizing deep learning to capture and quantify particle dispersion characteristics for structure-property analyses in polymer nanocomposites.

Boosting Dry Reforming of Methane Over NiCo/CeO2 Catalysts Treated by Hydrogen Plasma

ABSTRACTNickel (Ni)‐based catalysts are prospective materials for dry reforming of methane (DRM) reaction, but suffer from coke formation and limited activity for CO2 conversion. To improve the reactivity of Ni‐based catalysts, a promising strategy is introducing cobalt (Co) metal. Here, we construct highly efficient NiCo sites on CeO2 support by H2 plasma, which enables the catalyst to obtain a remarkable increase in DRM reaction than the samples treated by conventional H2 reduction. H2 plasma treatment results in the formation of highly dispersed NiCo alloy nanoparticles and high‐concentration oxygen vacancy. These features create large numbers of highly active sites to boost the activation of CH4 and especially CO2 and their catalytic reactions, resulting in strong coke resistance in the DRM reaction.

Application of nano-TiO2 and micro-ZnO on cementitious surfaces for self-cleaning façades by spray coating and dip coating: A comparative study

Building façades are constantly exposed to atmospheric pollution and various external agents that can degrade their aesthetic qualities and introduce degradation patterns that affect the durability and performance of the materials. Façades with self-cleaning properties are important in the modern construction industry and the conservation of historic buildings, as they reduce costs and allow the preservation of original surfaces without the need for invasive interventions that could compromise cultural heritage. This study does a comparative analysis of the application of photocatalytic coatings composed of aqueous dispersions of titanium dioxide nanoparticles (TiO₂) and zinc oxide microparticles (ZnO) on cementitious substrates for use on façades by two functionalisation methods: spray coating and dip coating. A comprehensive characterisation was carried out using techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and diffuse reflectance spectroscopy (DRS) to assess the morphology, crystal structure and light absorption properties of the photocatalyst particles while Energy Dispersive Spectroscopy (EDS) and scanning electron microscopy (SEM) were employed to evaluate the substrate. The self-cleaning performance was evaluated by monitoring the degradation of Rhodamine B (RhB) dye under simulated sunlight. Spectrophotometric analysis was used to assess the colour coordinates using a standard colour system (CIELAB colour space). The results showed that the photocatalytic coatings improved the surfaces' self-cleaning properties while maintaining the substrate's original aesthetics. Spray-applied micro-ZnO-based coatings showed the most significant effectiveness in terms of self-cleaning.

Investigation of the catalytic activity of trimetallic CuAgAu aerogels for the electrochemical reduction of CO<sub>2</sub> to CO

Given the growing demand for efficient catalysts in sustainable energy applications, this study investigates the structural characterization and catalytic activity of CuAgAu trimetallic aerogels synthesized via a sol-gel method. Transmission electron microscopy (TEM) revealed a porous network structure with uniformly dispersed trimetallic nanoparticles averaging 5-10 nm in size, which indicates a successful synthesis and nanostructure formation. X-ray diffraction analysis confirmed the formation of a face-centered cubic structure, with distinct diffraction peaks observed at positions corresponding to the (111), (200), and (220) planes of Cu, Ag, and Au, respectively. These structural features are critical for understanding the crystalline nature and stability of the aerogels. The catalytic activity of CuAgAu aerogels for CO2 reduction was evaluated using linear sweep voltammetry, which showed notable enhancements in current densities at various applied potentials relative to the reversible hydrogen electrode. These findings indicate the aerogels’ effectiveness as catalysts for CO2 conversion. Furthermore, Faradaic efficiency measurements revealed a high selectivity in the conversion of CO2 to CO, achieving a high Faradaic efficiency of 85%, which suggests that the aerogels’ capability to efficiently utilize electrons in producing CO, as a valuable precursor in renewable energy and chemical synthesis applications. The combination of structural integrity, catalytic performance, and high selectivity positions CuAgAu aerogels as promising approach for sustainable energy technologies.

"One-Stone, Two-Birds": Zinc-Rich Metal-Organic Frameworks as Precursors for High-Entropy Zn-Air Battery Electrocatalysts with Hierarchical Pore Structures.

The active sites of inexpensive transition metal electrocatalysts are sparse and singular, thus high-entropy alloys composed of non-precious metals have attracted considerable attention due to their multi-component synergistic effects. However, the facile synthesis of high-entropy alloy composites remains a challenge. Herein, we report a "one-stone, two-birds" method utilizing zinc (Zn)-rich metal-organic frameworks as precursors, by virtue of the low boiling point of Zn (907 °C) and its high volatility in alloys, high-entropy alloy carbon nanocomposite with a layered pore structure was ultimately synthesized. The experimental results demonstrate that the volatilization of zinc can prevent metal agglomeration and contribute to the formation of uniformly dispersed high-entropy alloy nanoparticles at slower pyrolysis and cooling rates. Simultaneously, the volatilization of Zn plays a crucial role in creating the hierarchically porous structure. Compared to the zinc-free HEA/NC-1, the HEA/NC-5 derived from the precursor containing 0.8 Zn exhibit massive micropores and mesopores. The resulting nanocomposites represent a synergistic effect between highly dispersed metal catalytic centers and hierarchical adsorption sites, thus achieving excellent electrocatalytic oxygen reduction performance with low catalyst loading compared to commercial Pt/C. This convenient zinc-rich precursor method can be extended to the production of more high-entropy alloys and various application fields.

Uptake of Magnetite Nanoparticles on Polydopamine Films Deposited on Gold Surfaces: A Study by AFM and XPS.

Polydopamine has the capacity to adhere to a large variety of materials and this property offers the possibility to bind nanoparticles to solid surfaces. In this work, magnetite nanoparticles were deposited on gold substrates coated with polydopamine films. The aim of this work was to investigate the effects of the composition and morphology of the PDA layers on the sticking of magnetite nanoparticles. The polydopamine coating of gold surfaces was achieved by the oxidation of alkaline solutions of dopamine with various reaction times. The length of the reaction time to form PDA was expected to influence the composition and surface roughness of the PDA films. Magnetite nanoparticles were deposited on these polydopamine films by immersing the samples in aqueous dispersions of nanoparticles. The morphology at the nanometric scale and the composition of the surfaces before and after the deposition of magnetite nanoparticles were investigated by means of AFM and XPS. We found that the amount of magnetite nanoparticles on the surface did not vary monotonically with the reaction time of PDA formation, but it was at the minimum after 20 min of reaction. This behavior may be attributed to changes in the chemical composition of the coating layer with reaction time.

Nanoparticle Clustering in Supraparticles to Control Magnetic Long‐Range Interactions

AbstractTo tailor superparamagnetic iron oxide nanoparticles (SPIONs) to the specific needs of diverse application fields, it is essential to understand not only their intrinsic properties but also their interactions with each other. Theoretical models predicting/explaining the magnetization behavior of macroscopic samples containing millions of SPIONs are intricate due to the complexity of the underlying relaxation mechanisms in alternating fields. This study introduces supraparticles (SPs) as model architectures to empirically investigate magnetic interactions within and between large SPION clusters (>100 nanoparticles (NPs)). For this purpose, NP dispersions containing SPIONs and silica (SiO2)NPs as non‐magnetic building blocks are spray‐dried to form binary SPs. Selective salt‐induced agglomeration of the two building block types before spray‐drying is utilized to tailor SP architectures, including control over SPION cluster size, shape, and proximity. Magnetic particle spectroscopy (MPS), operating under ambient conditions, reveals altered magnetization behavior for different cluster structures. Not only the nearest SPION neighbors, but the whole cluster structure up to several micrometers is decisive for the magnetization behavior. This highlights the importance of long‐range magnetic interactions. This work presents a versatile approach for designing model architectures to advance empirical interaction studies between SPIONs in macroscopic samples.

Pd Nanoparticles Immobilized on Pyridinic N-Rich Carbon Nanosheets for Promoting Suzuki Cross-Coupling Reactions.

Palladium (Pd) catalysts play a crucial role in facilitating Suzuki cross-coupling reactions for the synthesis of valuable organic compounds. However, conventional heterogeneous Pd catalysts often encounter challenges such as leaching and deactivation during reactions, leading to reduced catalytic efficiency. In this study, we employed an innovative intercalation templating strategy to prepare two-dimensional carbon nanosheets with high nitrogen doping derived from petroleum asphalt, which were utilized as a versatile support for immobilizing Pd nanoparticles (Pd/N-CNS) in efficient Suzuki cross-coupling reactions. The results indicate that the anchoring effect of high-pyridinic N species on the two-dimensional carbon nanosheets enhances interactions between Pd and the support, effectively improving both the dispersibility and stability of the Pd nanoparticles. Notably, the Pd/N-CNS catalyst achieved an overall turnover frequency (TOF) of 2390 h-1 for the Suzuki cross-coupling reaction under mild conditions, representing approximately a nine-fold increase in activity compared to commercial Pd/C catalysts. Furthermore, this catalyst maintained an overall TOF of 2294 h-1 even after five reaction cycles, demonstrating excellent stability. Theoretical calculations corroborate these observed enhancements in catalytic performance by attributing them to improved electron transfer from Pd to the support facilitated by abundant pyridinic N species. This work provides valuable insights into feasible strategies for developing efficient catalysts aimed at sustainable production of biaromatic compounds.

Development and 4D printing of magneto-responsive PMMA/TPU/Fe3O4 nanocomposites with superior shape memory and toughness properties

This paper introduces 4D printing of composites of polymethyl methacrylate (PMMA) and thermoplastic polyurethane (TPU) reinforced with Fe3O4 particles for the first time. PMMA/TPU blends with 70/30 wt% are selected as matrix with the best compatibility based on dynamic mechanical thermal analysis. Fe3O4 nanoparticles are added to the blends with 10 %, 15 % and 20 % weight ratios. Their addition enables remote actuation of the materials in a high frequency alternating magnetic field. Field emission scanning microscopic images confirms a full dispersion of nanoparticles inside the polymeric matrix. Nanocomposites with 20 wt% of Fe3O4 can perfectly recover the permanent shape within 1.5 min in the magnetic field. They also reveal perfect shape memory properties in the hot water. Moreover, all samples display a perfect shape fixity ratio. The addition of TPU significantly enhances the toughness and flexibility of the PMMA matrix. It is found that Fe3O4 nanoparticles further enhance the mechanical strength by 10 % to 15 %, although they reduce the strain at break from 17 % to 14 %. Finally, a gripper is 4D printed and its excellent performance in the magnetic field is demonstrated.

Z-scheme driven charge transfer in g-C3N4/α-Fe2O3 nanocomposites enabling photocatalytic degradation of crystal violet and chromium reduction

In this study, we demonstrated the design and fabrication of iron oxide-embedded protonated graphitic carbon nitride (α-Fe2O3/p-g-C3N4) nanocomposites for photocatalytic dye degradation and heavy metal reduction applications under sunlight irradiation. The developed nanocomposites, with varying weight percentages of α-Fe2O3, were characterized for their structural (XRD, FTIR, XPS), optical (absorption and photoluminescence), morphological (FE-SEM, TEM), and electrochemical (EIS) properties to elucidate their structure-property relationships. The synthesis method ensures the uniform dispersion of α-Fe2O3 nanoparticles, with a particle size range of 50–60 nm, onto p-g-C3N4. XPS analysis suggests the formation of an electrical layer at the interface of α-Fe2O3/p-g-C3N4, facilitating the formation of a Z-scheme heterojunction. The photoluminescence and EIS spectra of the nanocomposite indicated effective separation and transfer of photo-induced charge carriers, aided by a reduced bandgap energy of ∼2.63 eV. Notably, the optimized 10 wt% α-Fe2O3/p-g-C3N4 nanocomposite exhibited superior photocatalytic activity, degrading nearly 100 % of crystal violate dye and reducing 98 % of Cr(VI) ions, compared to bare p-g-C3N4, which degraded around 43 % of the dye and reduced 39 % of Cr(VI) ions under sunlight irradiation. Scavenger studies indicated that α-Fe2O3/p-g-C3N4 nanocomposites produce adequate superoxide anions and hydroxyl radicals for dye degradation and heavy metal ion reduction. The composite also demonstrated consistent recyclability up to 5 cycles with around 100 % cyclical efficiency. The pH-dependent photoreduction and cyclic dye degradation by the 10 wt% α-Fe2O3/p-g-C3N4 photocatalyst indicated excellent stability, making it suitable for the treatment of multi-pollutant wastewater.

A sustainable strategy to improve photocatalytic degradation properties of CuO and CuO-rGO nanocomposite using Eucalyptus leaf extract

In this study, Copper oxide (CuO) nanoparticles were synthesized using a sustainable approach. The process comprised Eucalyptus leaf extract as both a biological capping agent and a reducing agent. The synthesis process used a one-pot hydrothermal technique to efficiently combine CuO nanoparticles with reduced graphene oxide (rGO). Analytical methods were utilized to investigate the prepared nanocomposite's structural, crystalline, morphological, functional, optical, and thermal characteristics. The prepared sample was analyzed using X-ray diffraction, which revealed that CuO nanoparticles have a monoclinic crystal structure, and no impurity peaks were observed. Field emission scanning microscopes displayed the uniform dispersion of spherical CuO nanoparticles with layered and non-agglomerated, resembling a sponge-like structure of rGO. The microstructural analysis also confirmed the dispersion of copper inside reduced graphene oxide (rGO) sheets. The optical properties, including light absorption and bandgap width, were investigated using UV–visible spectroscopy using bandgap energies of 2.5 and 2.8 eV. In addition, the nanocomposite's ability to degrade cationic Rhodamine 6G and anionic Rose Bengal dyes by photocatalysis was evaluated. The degradation of RB and Rh6G dyes was characterized by nanocatalysis using UV–visible spectroscopy and a pseudo-first-order kinetics model. The pseudo-first-order degradation kinetic rate of Rhodamine 6G was determined to be 2.55 x 10−2 min−1, indicating that the nanocomposite effectively initiates this dye's degradation. The results showed that dye degradation was effective even at reduced catalyst concentrations.

In-situ sol-gel process for the formulation of Bis-GMA/TEGDMA/silica dental nanocomposite

A novel dental composite based on Bis-GMA/TEGDMA resin incorporating silica nanoparticles was developed using an innovative in situ sol-gel process. This method ensures a homogeneous dispersion of fillers, effectively preventing their agglomeration during preparation. It results in an interpenetrating network in which polymer chains and silica particles are intimately mixed, thereby enhancing the structural and mechanical properties and minimizing the volumetric shrinkage of the dental restorative material.The formation of organic and inorganic network was confirmed by infrared spectroscopy. The in situ synthesis enabled uniform dispersion of silica nanoparticles within the material as evidenced by transmission electron microscopy, scanning electron microscopy and energy dispersive spectroscopy.The results showed that the prepared composite containing 50 wt% fillers achieved hardness, modulus of elasticity, compressive strength and flexural strength values of 72 HV, 10 GPa, 240 MPa, and 110 MPa, respectively. These properties are comparable to those of the commercial “Nt Premium” composite containing 75 % preformed silica nanoparticles, which has hardness, modulus of elasticity, compressive strength and flexural strength values of 68 HV, 10 GPa, 220 MPa and 95 MPa, respectively. Additionally, the study revealed a significantly reduced volumetric shrinkage of 0.5 % for our composite, compared with over 2.2 % for Nt Premium. This groundbreaking approach holds substantial promise for developing advanced dental materials, offering superior performance and enhanced longevity in clinical applications.

Optimising Nanoparticle Dispersion Time for Enhanced Thermomechanical Properties in DGEBA-Based Shape Memory Polymer Composites

Shape-memory polymers (SMPs) are smart materials that can change shape upon an external stimulus. This phenomenon is called the shape memory effect (SME), which is caused by entropy change due to rapid molecular motion in the polymer segments. Due to the inherently weak thermomechanical properties, use of SMPs is limited in many engineering applications. Therefore, SMPs are often reinforced with fibres and nanoparticles (NPs). NPs offered greater flexibility due to their superior physical, chemical, electrical, mechanical, and thermal properties. However, the homogeneous distribution of NPs is crucial for composition’s stability and enhancement of the base material’s properties. Among the different techniques used for dispersing NPs, ultrasonic irradiation has shown excellent emulsifying and crushing performance. The sonication process is essential for mitigating agglomerates; however, prolonged sonication time probably increases epoxy temperature, micro-bubbles, cavitation, breaking apart molecules and finally degrading the epoxy resin performances. This paper provides critical insight of nanoparticle dispersion into diglycidyl ether of bisphenol A epoxies (DGEBA). DGEBA epoxy resin was added to TiO2 NPs and sonicated for 60 min with 5 min intervals while the temperature of epoxy was maintained below 60oC by using a water cooling throughout the sonication process. The process parameters such as amplitude, mode, epoxy volume and the weight percentage of NPs were kept constant. After each sonication step, Fourier-transform infrared spectroscopy (FTIR) was performed using Thermo Scientific™ and analysed through OMNIC™ Professional quantitation software. In accordance with FTIR results, until 30 min of the sonication, DGEBA resin was not degraded. In order to confirm the performances and the reinforcing effect of NPs, thermo-mechanical and shape memory properties were compared with the neat specimen. The outcomes of this research have suggested quick guidance to find optimum NP dispersion time for DGEBA resins, which has been hardly studied before.

A strategy of consistent X-ray and neutron double-difference pair distribution function analysis of nanoparticle dispersions

AbstractIt has been demonstrated that the X-ray pair distribution function (PDF) formalism allows for the identification of very small signal contributions in multi-component systems by the difference and double-difference PDF (dd-PDF) approach. Due to their stronger interaction with light elements compared to X-rays, neutrons are often beneficial or complementary for the characterization of modern materials. Here, it is demonstrated that the dd-PDF strategy previously developed for X-ray PDF data can successfully be applied to neutron PDF data despite much lower count rates compared to X-rays. The dd-PDF strategy was employed for the investigation of aqueous iron oxide nanoparticle (IONP) dispersions. At the Near and InterMediate Range Order Diffractometer (NIMROD) at ISIS, the IONPs could even be investigated in pure water, whereas at the Nanoscale Ordered Materials Diffractometer (NOMAD) at SNS, heavy water had to be used, but additional information could be retrieved from modelling the data of IONP powder in the dry state and with adsorbed (heavy) water. The simple and robust approach can easily be adapted for the use in other multicomponent systems, like heterogenous catalysts or battery systems. Graphical Abstract

Highly-dispersed CdS nanoparticles coating hierarchical Ni@NC derived from ultrathin nanosheets NMOF-Ni: Photocatalytic hydrogen evolution coupled with alcohol oxidation

Photocatalytic water-splitting into H2 in conventional procedures often requires sacrificial agents to consume unutilized holes to boost the reaction. Herein, we cast off the dependence on the addition of sacrificial agents and develop a dual-functional photocatalyst CdS/Ni@NC for coupling H2 evolution with value-added benzyl alcohol (BA) oxidation in anaerobic aqueous solution, wherein CdS/Ni@NC was synthesized by in-situ anchoring of CdS nanoparticles (NPs) onto NMOF-Ni ultrathin nanosheets-derived nitrogen-doped wrinkled graphitic carbon layers encapsulated metallic Ni NPs (Ni@NC). The optimized photocatalyst CdS/Ni@NC(5) achieves a high visible-light-driven H2 evolution rate of 1881 μmol·g−1·h−1 and a benzaldehyde (BAD) yield of 3254.2 μmol·g−1·h−1, with nearly 100 % selectivity over a 6 h period, which are 32.6 and 10.5 folds of that for CdS alone, respectively. Further in-depth experimental characterizations reveal that the hierarchical Ni@NC serves as an ideal support to enable high dispersion of CdS NPs, thus improving light absorption and facilitating full contact with reactants. Besides, the widely distributed Ni NPs, effectively shielded by nitrogen-doped wrinkled graphitic carbon layers, can not only promote photogenerated charge transfer for enhanced H2 production but also facilitate the cleavage of the Cα–H bond in BA, contributing to achieving high aldehyde selectivity. This study, integrating carbonized ultrathin nanosheets NMOF-Ni with CdS to synergistically enhance surface redox reactions, holds significant promise for advancing the development of high-performance photocatalysts for integrated production of solar hydrogen and value-added solar chemicals.

An Extensive Study of Metal Matrix Composites and their Various Properties for Different Uses

This study examines the creation and development of composite materials, from conventional techniques to their innovative uses in numerous industries. Composite materials that are robust, versatile, and resilient have advanced significantly, especially with the application of nanotechnology and hybrid fiber reinforcements. Composite materials are difficult to machine due to their anisotropic and non-homogeneous structure, as well as the high abrasiveness of their reinforcing parts. This typically results in the workpiece becoming damaged and the cutting tool wearing down very rapidly. On composite materials, traditional machining methods such as turning, drilling, and milling can be applied with the appropriate tool design and operating parameters. An overview of the various issues related to the conventional machining of the main types of composite materials is given in this work. This article examines novel matrix materials, forms of reinforcement, and production procedures to show how advanced metallic matrix nano composites and fiber-reinforced polymers are replacing traditional composites. Special emphasis is given to the strict manufacturing conditions in addition to the homogenous dispersion of nanoparticles and damage-free machining of fiber composite materials. The essay also discusses how sustainable alternatives, including reinforcements made of natural fibers, affect the ecosystem. This study aims to offer a comprehensive analysis and case studies.

Study of Cytotoxicity of Selenium Nanoparticles Synthesized Using Artificial Metal-Binding Tumor-Specific Protein W8-3C

For the first time, the pW8-3C construct encoding the artificial tumor-specific protein W8-3C with the addition of 3 residues of free Cys at the C end was created and described. Using purified W8-3C protein, dispersions of nanoparticles 75.24 nm in diameter at polydispersity index (Pdi) of 0.064 and Se content of 1566 µg/mL were obtained and characterized for the first time. The dispersions remained stable upon storage for 6 months at +4°C. For comparison, the maximum Se content in the nanoparticle dispersion obtained in the presence of W8-3C protein and Pluronic F-127 was 399 µg/ml. The cytotoxic activity of the obtained nanoparticles was studied on transplanted cells of human tumor lines: HeLa (cervical carcinoma), U-87 MG (glioblastoma), MCF-7 (breast carcinoma) and HCT-116 (colon carcinoma) and compared with that on the diploid human fibroblast line WI-38 in vitro. It was shown that the IC50 of Se nanoparticles obtained using the W8-3C protein for tumor lines ranged from 5.25 to 8.37 µg/ml, while the IC50 for normal fibroblasts was 14.3 µg/ml (difference in values by a factor of 1.7–2.7 times).

Highly Efficient Depolymerization of Polycarbonate Enabled by Dispersions of Ultrasmall ZnO Nanoparticles

Highly Efficient Depolymerization of Polycarbonate Enabled by Dispersions of Ultrasmall ZnO Nanoparticles

Dispersion of Hydrophilic Nanoparticles in Natural Rubber with Phospholipids

Coarse-grained molecular dynamics (CGMD) simulations were employed to investigate the effects of phospholipids on the aggregation of hydrophilic, modified carbon-nanoparticle fillers in cis-polyisoprene (cis-PI) composites. The MARTINI force field was applied to model dipalmitoylphosphatidylcholine (DPPC) lipids and hydrophilic modified fullerenes (HMFs). The simulations of DPPC in cis-PI composites show that the DPPC lipids self-assemble to form a reverse micelle in a rubber matrix. Moreover, HMF molecules readily aggregate into a cluster, in agreement with the previous studies. Interestingly, the mixture of the DPPC and HMF in the rubber matrix shows a cluster of HMF is encapsulated inside the DPPC reverse micelle. The HMF encapsulated micelles disperse well in the rubber matrix, and their sizes are dependent on the lipid concentration. Mechanical and thermal properties of the composites were analyzed by calculating the diffusion coefficients (D), bulk modulus (κ), and glass transition temperatures (Tg). The results suggest that DPPC acts as a plasticizer and enhances the flexibility of the HMF-DPPC rubber composites. These findings provide valuable insights into the design and process of high-performance rubber composites, offering improved mechanical and thermal properties for various applications.