Spherical Morphology Research Articles

Synthesis of aqueous NiFe2O4-Fe3O4 hybrid magnetic nanofluids and investigation on electrical conducting behaviour

Highly stable aqueous magnetic mono nanofluids of nickel ferrite (NiFe2O4), magnetite (Fe3O4), and hybrid magnetic nanofluids of NiFe2O4-Fe3O4 are synthesized through a two-step method. The structural analysis of the NiFe2O4 and Fe3O4 nanoparticles made through X-ray diffraction identifies their spinel cubic structure. The magnetic studies indicate their superparamagnetic nature, which is further confirmed through the Langevin fitting of the experimental data. The monodomain nature of nanoparticles is verified using the coupling constant, and a spherical morphology is observed using a transmission electron microscope. The surface charge of the nanoparticles is studied through zeta potential analysis. The electrical conductivity of the aqueous mono and hybrid magnetic nanofluids is measured for various concentrations and temperatures. The hybrid magnetic nanofluids show higher electrical conductivity values than those of both the mono nanofluids. For instance, NiFe2O4-Fe3O4 (1.2 vol%) hybrid nanofluid is found to have a conductivity value of 18.91 μS/cm that is 1.5 times enhanced than that of Fe3O4 mono nanofluid (12.87 μS/cm) and three times enhanced than that of NiFe2O4 (6.43 μS/cm) mono nanofluid of same volume percentage at 303 K. A Maximum enhancement of 136 % is obtained for 1.2 vol% hybrid nanofluid with respect to water at 303 K and this enhancement further increases to 196 % with the rise in temperature to 323 K. There is no theoretical model found in literature to explain the electrical conductivity of hybrid nanofluids. Maxwell, Bruggeman, Cruz, and Shen models are applied to explain the conductivity of hybrid magnetic nanofluids. Through a comparison of experimental values with theoretical values, it is found that the Shen model, if modified suitably, can explain the electrical conduction of hybrid magnetic nanofluids. Also, the electrical conduction mechanism in hybrid magnetic nanofluids is described in terms of electrophoretic charge transportation and the Brownian motion. In addition, the magneto-electrical conductivity study is performed by measuring the electrical conductivity by applying a magnetic field of various strengths. The electrical conductivity, magneto-electrical conductivity studies and an understanding of electrical conduction mechanism are highly significant for magnetically transportable electronic cooling and conducting applications of hybrid magnetic nanofluids.

Characterization of the Biosynthesized Silver Nanoparticles from the Sea Cucumber Bohadschia marmorata (Jaeger, 1833)

Silver nanoparticles (AgNPs) from marine invertebrates, particularly sea cucumbers, are relatively few or even lacking. This study aimed to determine the potential of the body wall of Bohadschia marmorata as reducing agent to synthesize silver nanoparticles and characterize the generated AgNPs using a direct and environment-friendly procedure. Although limited, the generated AgNPs were confirmed with an absorbance peak of 416 nm, indicative of surface plasmon resonance, with strong signals of elemental silver acquired by EDS at 3 keV. The potential functional groups responsible for the reduction of silver ions and capping of the nanoparticles include O–H (alcohol and carboxylic acids), C–C (alkene), N–H, and C–N (amine) groups detected by FT-IR. Scanning electron microscopy showed a nearly spherical morphology with an approximate size of 288 nm which tends to polydisperse and aggregate. Thus, this study showed that the sea cucumber body wall can be used in the biosynthesis of AgNPs. However, refinement of the procedures and operational parameters used is needed to produce more and better-quality nanoparticles.

Synthesis and photodegradation performance of a heterostructure ferromagnetic photocatalyst based on MWCNTs functionalized with (3-glycidyloxypropyl)trimethoxysilane and decorated with tungsten trioxide for metronidazole and acetaminophen degradation in aqueous environments.

The presence of metronidazole (MNZ) and acetaminophen (ACE) in aquatic environments has raised growing concerns regarding their potential impact on human health. Incorporating various patterns into a photocatalytic material is considered a critical approach to achieving enhanced photocatalytic efficiency in the photocatalysis process. In this study, WO3 nanoparticles, which were immobilized onto ferromagnetic multi-walled carbon nanotubes that were functionalized using (3-glycidyloxypropyl)trimethoxysilane (FMMWCNTs@GLYMO@WO3), exhibited remarkable efficiency in removing MNZ and ACE (93% and 97%) in only 15 min. In addition, the new visible-light FMMWCNTs@GLYMO@WO3 nanoparticles as a magnetically separable photocatalyst were characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), EDS-mapping, vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), diffuse reflectance spectroscopy (DRS), high-performance liquid chromatography (HPLC), and total organic carbon (TOC) due to detailed studies (morphological, structural, magnetic and optical properties) of the photocatalyst. In-depth spectroscopic and microscopic characterization of the newly developed ferromagnetic FMMWCNTs@GLYMO@WO₃ (III) photocatalyst revealed a spherical morphology, with nanoparticle diameters averaging between 23 and 39 nm. Compared to conventional multiwall carbon nanotube and WO₃ photocatalysts, FMMWCNTs@GLYMO@WO₃ (III) demonstrated superior photocatalytic activity. Remarkably, it exhibited excellent reusability, maintaining its efficiency over a minimum of five cycles in the degradation of metronidazole (MNZ) and acetaminophen (ACE).

Synthesis and characterization of oleic acid-stabilized cobalt ferrite @MCM-41/nanocomposites for pH-responsive drug delivery

This study presents composite nanoparticles combining cobalt ferrites-oleic acid (CF-OA) and mesoporous silica (MCM-41) for drug delivery. Temperature-dependent analyses at 25 and 42 °C reveal distinct alterations in particle size and distribution, emphasizing the role of oleate complexes in stabilizing the nanocomposites. Power of Laws calculations (n = 0.58, m = 0.44) assessed diffusion and matrix erosion effects, highlighting the pH-responsive behavior. Results showed CF-OA@MCM-41with nanometric scale and predominantly spherical morphology influenced by temperature variations. Nitrogen BET analysis revealed a surface area of 542.1 m2g−1 and a pore volume of 1.1 cm3g−1. Drug release studies demonstrated controlled doxorubicin (DOX) release from CF-OA@MCM-41. In vivo studies showed significant tumor growth suppression (liver cancer): average tumor volume in D-C@M group was 167.8 mm3 after 21 days, compared to 1953.8 mm3, 1203.6 mm3, and 269 mm3 for PBS, CF-OA@MCM-41, and DOX alone respectively. In vitro, a 3 µg mL−1 concentration showed no significant 293 T cell viability change and increased HEP G2 cell viability. Significant HEP G2 cell viability inhibition occurred at 1 and 2 µg mL−1 CF-OA@MCM-41 carrying DOX, with p-values < 0.01 and < 0.001. CF-OA@MCM-41 nanoparticles exhibit promising potential for targeted cancer therapy due to their pH sensitivity and controlled drug release capabilities.

Antioxidant response of Calendula officinalis L. assisted synthesized zinc oxide nanoparticles

The over-production of free radicals in the body causes oxidant damage in the body. Currently, zinc oxide nanoparticles (ZnO NPs) are gaining attention of most scientists because of their excellent physical, chemical, and biological properties. In this work, the ZnO NPs were synthesized using the petal extract of C. officinalis L. An absorbance spectrum of the synthesized ZnO NPs was recorded using an ultraviolet-visible (UV–Vis) spectrophotometer. The absorbance band around 368 nm confirms the formation of ZnO NPs. The transmission electron microscopy (TEM) analysis clearly shows that the most of the ZnO NPs are spherical in shape with average particle size ∼ 16 nm. The field emission scanning electron microscope (FE-SEM) result demonstrates the spherical morphology with large agglomeration of the particles. The energy-dispersive x-ray spectroscopy (EDS) result confirms the presence of Zn in the synthesized NPs’. The x-ray diffraction (XRD) peaks represent the crystalline structure of the ZnO NPs with average particle size ∼ 27.22 nm. Fourier transform infra-red (FT-IR) spectrum of synthesized ZnO NPs was recorded in the range of 4000-500 cm−1. The ester and carboxylic groups were found at 1017 cm−1, 952 cm−1, 688 cm−1, 609 cm−1, and 514 cm−1 due to the presence of Zn-O band stretch in the FT-IR spectrum. Further synthesized material was evaluated by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay to evaluate its antioxidant activity. It showed that ZnO NPs exhibited significant antioxidant activity through scavenging DPPH free radicals. Thus, it could be seen that the synthesis of naturally occurring plant product ZnO NPs acts as an alternative chemical antioxidant. Hence, the herbal synthesized ZnO NPs are proven to be a potent antioxidant agent and can be used in several medicinal applications.

Development of gentamicin bilosomes laden in-situ gel for topical ocular delivery: optimization, in-vitro characterization, toxicity, and anti-microbial evaluation

Purpose: The eye drops are the prominent preparation used to treat surface eye disease (bacterial conjunctivitis). However, they have some limitations i.e., short corneal residence, resulting in low ocular bioavailability and necessitating frequent dose administration. The present study developed gentamicin (GE) bilosomes (BM)- laden in-situ gel to improve therapeutic activity. The in-situ gel system is initially in sol form before administration and converted into gel form in physiological eye conditions. Method: The GE-BM was developed using the thin film hydration technique and optimized by D-optimal design. GE-BM was characterized for vesicle size, entrapment efficiency, zeta potential, morphology, and FTIR. The optimized GE-BM (GE-BMopt) was incorporated into an in-situ gel and assessed for physicochemical characteristics. GE-BMopt in-situ gel was evaluated for in-vitro release, ex-vivo permeation, toxicity, and antimicrobial study. Result: GE-BMopt has a vesicle size of 185.1±4.8nm, PDI of 0.254, zeta potential of 27.6 mV, entrapment efficiency of 81.86±1.29 %, and spherical morphology. The FTIR study presented no chemical interactions between GE and excipients. GE-BMopt in-situ gel (GE-BMoptIG4) showed excellent viscosity, gelling strength, and ex-vivo bio-adhesion. GE-BMopt-IG4 showed significant high and sustained release of GE (78.08± 4.73% in 12h). GE-BMopt-IG4 displayed 3.27-fold higher ex-vivo goat corneal permeation than a pure GE solution. GE-BMopt-IG4 showed good corneal tolerance without any damage or irritation. GE-BMopt-IG4 showed significantly (P&lt;0.05) higher anti-bacterial activity (ZOI) against Staphylococcus aureus and Escherichia coli than pure GE solution. Conclusion: The study determined that the BM in-situ gel system can serve as a substitute carrier for GE to enhance its therapeutic effectiveness, and further preclinical studies are required.

Ti3C2Tz Supported Pulse‐Electrodeposited Pt Nanostructures for Enhanced Acidic Electrochemical Hydrogen Evolution

Platinum (Pt)‐based electrocatalysts are considered benchmark materials for the hydrogen evolution reaction (HER) in acidic solution. However, widespread use is limited by the high price of Pt. Tuning the Pt morphology to increase the catalytic surface area for the same mass loading is therefore essential to increase its utilization. Herein, single Ti3C2Tz flakes were deposited by electrophoresis onto a carbon‐fiber gas diffusion layer, after which Pt nanostructures were selectively deposited onto the Ti3C2Tz flakes by pulse electrodeposition. It was observed that the pulse on‐time (ton) and duration had a significant effect on the morphology and activity of the composite electrode towards HER. Flower‐like and spherical morphologies were produced at long and short values of ton, respectively. As‐synthesized electrocatalysts were studied for HER in 0.5 M sulfuric acid (H2SO4). The catalyst with the lowest Pt loading (10 mg/cm2), exhibited outstanding HER performance. It attained a current density of 10 mA/cm2 at an overpotential of 38 mV, close to that of commercial carbon supported platinum (Pt/C, Vulcan XC). This catalyst exhibited a high turnover frequency (23.9 H2 s‐1 @ 100 mV), small Tafel slope (41 mV/dec), and high mass‐specific activity (2.45 A/mgPt @ 100 mV).

Physical properties of La3+ ion doped Ni[sbnd]Zn based spinel ferrite nanomaterials for technological applications

Spinel ferrite nanoparticles are extensively utilized in various everyday applications due to their exceptional capabilities. They are highly effective and efficient for various applications such as energy storage devices, microwave, electrode design, fuel cells, and recording media. Based on these applications, five samples of lanthanum doped nickel‑zinc spinel ferrite Ni0.5Zn0.5LaxFe2-xO4 nanoparticles were synthesized using the sol-gel auto-combustion technique. The lanthanum concentrations varied as x = 0.00, 0.05, 0.10, 0.15 and 0.20. X-ray diffraction (XRD) analysis revealed the formation of single phase cubic spinel structure of the prepared samples. The crystallite size was determined using the Scherrer formula and the values lies in the range of 9.22 to 20.09 nm. The chemical composition of the prepared samples was confirmed using Fourier transform infrared spectroscopy (FTIR) analysis. Transmission electron microscopy (TEM) confirmed the agglomeration and spherical shape morphology of the nanoparticles with an average particle size of 40 nm. Magnetic properties along with La3+ ion concentrations were investigated using the vibrating sample magnetometer (VSM). The dielectric properties of the prepared samples were carried out using impedance analyzer with an applied frequency ranging from 1 MHz to 3 GHz. Furthermore, the polarization mechanism in the applied frequency range was discussed with relaxation behavior at high frequency. The impact of La3+ concentrations on different parameters such as dielectric constant, impedance, electric modulus, tangent loss, and Ac conductivity were also investigated. The investigation of dielectric parameters. The relaxation mechanism at high frequency provided a significant impact of such type of materials to store energy due lake of hopping between the tetra and octahedral sites by addition of La3+ doping. The prepared samples exhibit excellent magnetic as well dielectric properties which makes suitable for microwave devices and soft magnetic applications.

Preparation and characterization of Iturin A/chitosan microcapsules and their application in post-harvest grape preservation

Iturin A (IA) encapsulated in chitosan (CS) microcapsules (IA/CS) underwent thorough physicochemical characterization using thermogravimetric analysis (TGA), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). SEM confirmed the smooth, spherical morphology of the IA/CS microcapsules, while FTIR revealed complex intermolecular interactions between IA and CS. TGA demonstrated thermal stability within the 0–100 °C range, while particle size analysis revealed an average diameter of 553.4 nm. To evaluate IA/CS efficacy in post-harvest grape preservation, grapes were treated with sterile water (CK), 10 g/L CS, 0.1 g/L IA/CS, and 0.1 g/L chitosan empty microcapsules (CKM), then stored at 25 °C for 16 days. IA/CS significantly reduced decay and respiration intensity by 52.3 % and 23.8 %, respectively, compared to CK. IA/CS treatment also inhibited abscission rate, weight loss, firmness reduction, total soluble solids consumption, titratable acidity consumption, polyphenol oxidase, and peroxidase activities on par with CS treatment (p > 0.05), but performed better than CK (reductions of 26.9 %, 41.2 %, 25.8 %, 27.2 %, 24.2 %, 19.4 %, and 17.4 %, respectively) and CKM (p < 0.05). Sensory evaluation confirmed that IA/CS effectively suppressed decay, slowed post-harvest metabolic activity, and maintained grape quality. Therefore, IA/CS microcapsules offer a promising method for extending grape shelf life and preserving quality.

Lysosomal Activation Mediated by Endocytosis in J774 Cell Culture Treated with N-Trimethyl Chitosan Nanoparticles.

Safety and effectiveness are the cornerstone objectives of nanomedicine in developing nanotherapies. It is crucial to understand the biological interactions between nanoparticles and immune cells. This study focuses on the manufacture by the microfluidic technique of N-trimethyl chitosan/protein nanocarriers and their interaction with J774 cells to elucidate the cellular processes involved in absorption and their impact on the immune system, mainly through endocytosis, activation of lysosomes and intracellular degradation. TEM of the manufactured nanoparticles showed spherical morphology with an average diameter ranging from 36 ± 16 nm to 179 ± 92 nm, depending on the concentration of the cargo protein (0, 12, 55 μg/mL). FTIR showed the crosslinking between N-trimethyl chitosan and the sodium tripolyphosphate and the α-helix binding loss of BSA. TGA revealed an increase in the thermal stability of N-trimethyl chitosan/protein nanoparticles compared with the powder. The encapsulation of the cargo protein used was demonstrated using XPS. Their potential to improve cell permeability and use as nanocarriers in future vaccine formulations was demonstrated. The toxicity of the nanoparticles in HaCaT and J774 cells was studied, as well as the importance of evaluating the differentiation status of J774 cells. Thus, possible endocytosis pathways and their impact on the immune response were discussed. This allowed us to conclude that N-trimethyl chitosan nanoparticles show potential as carriers for the immune system. Still, more studies are required to understand their effectiveness and possible use in therapies.

Formulation and Evaluation of Nicotinamide Microsponges – The First Step Towards the Development of a Novel Topical Dosage Form

The objective of this work was to formulate and analyze microsponges of nicotinamide. The said formulation was created using the emulsion solvent diffusion technique, and a 3 level two factor-based factorial design was applied to optimize the effect of the stabilizer (X1), as well as drug (X2), amounts on the entrapment efficiency (Y1) and average particle size (Y2). Various parameters, such as flow characteristics, percentage yield, drug concentration, in-vitro drug release tests, entrapment efficiency, and scanning electron microscopy (SEM), were evaluated. All parameters were found to be within the acceptable range. Design Expert 13 was employed to optimize the microsponges, and the optimal batch was determined by examining the desirability data. From this analysis, the optimal amounts of drug and stabilizer were found to be 302.87 and 59.71 mg, respectively. The reliability of the preparation and evaluation of the optimized batch was confirmed by a less than 5% discrepancy between the observed and predicted values of parameters. SEM images revealed that the microsponges were prepared with uniform and spherical morphology. The study concluded that nicotinamide microsponges were successfully prepared and evaluated. Further steps will involve incorporating this formulation into a novel topical dosage form.

Evolution of Morphology, Particle Size and Oxidation Resistance of Recycled Ti-6Al-4V Powders Prepared by Planetary Ball Milling

AbstractPlanetary ball milling is a high-energy ball milling technique that is widely used for the synthesis of alloy and composite powders with micrometer or nanometer particle sizes. The effect of process control agent (PCA) content (wt%) and milling time on the morphology, particle size and distribution, crystallite structure, apparent density and oxidation resistance of recycled T-6Al-4V alloy powders from lathe chips is investigated in this study. To investigate the effect of the PCA on the properties of the Ti-6Al-4V alloy particles, methanol is used as the PCA in various amounts of 0.5, 1 and 2 wt%. The milling is carried out using 20:1 of ball-to-powder ratio (BPR) and 400 rpm of milling speed. A morphological change from scrap form to flake-like shape, from flake-like morphology to irregular and semispherical shape and finally from semispherical form to spherical morphology is observed with increase in milling time for all PCA ratios. The results showed that the average particle sizes (D50) are 20, 18.1 and 21.8 μm after milling of 360 min with 0.5 wt%, 1 wt% and 2 wt% PCA, respectively. Results show that the most suitable recycled Ti-6Al-4V powders for powder-based manufacturing techniques are produced between 180 and 360 min of milling with 2 wt% PCA.

Poly(allylamine)-adorned heptylcarboxymethyl galactomannan nanocarriers of canagliflozin for controlling type-2 diabetes: Optimization by Box-Behnken design and in vivo performance

In the past three decades, the prevalence of type-2 diabetes has arisen dramatically in countries of all income levels. A novel, most effective nanotechnology-based strategy may reduce the prevalence of diabetes. Recently, the shell-crosslinked polysaccharide-based micellar nanocarriers (MNCs) have shown great promise in terms of stability, controlled drug release, and improved in vivo performance. In this study, heptyl carboxymethyl guar gum was synthesized and characterized by ATR-FTIR, 1HNMR spectroscopy, surface charge, critical micelle concentration (23.9 μg/mL), and cytotoxicity analysis. Box-Behnken design was used to optimize the diameter, zeta potential, drug entrapment efficiency (DEE), and drug release characteristics of poly (allylamine)-crosslinked MNCs containing canagliflozin. The optimized MNCs revealed spherical morphology under TEM and had 149.3 nm diameter (PDI 21.2 %), +53.8 mV zeta potential, and 84 % DEE. The MNCs released about 63 % of the drug in 12 h under varying pH of the simulated gastrointestinal fluid. DSC and x-ray analyses suggested amorphous dispersion of drugs in the MNCs. CAM assay demonstrated the biocompatibility of the MNCs. The MNCs showed hemolysis of <1 %, 85 % mucin adsorption, and stability over three months. The MNCs demonstrated excellent anti-diabetic efficacy in streptozotocin-nicotinamide-induced diabetic rats, continuously lowering blood glucose levels up to 12 h.

Photocatalytic Degradation of Toxic Rhodamine B Dye by Green‐Synthesised Activated Carbon‐Supported Cobalt Doped ZnO With Further Assessment of ZnO Nanoparticles in Antimicrobial Applications

AbstractThis work investigates the synthesis of ZnO nanoparticles, cobalt (Co)‐doped ZnO, and Activated Carbon (AC) ‐Co doped ZnO via green precipitation technique. AC developed from lotus stems and precipitated by lotus leaf extract. Comprehensive structural, optical, and morphological investigations by FT‐IR, XRD, FE‐SEM, EDX, HR‐TEM, UV‐DRS, PL, and XPS studies are used to characterize the photocatalysts. The ZnO nanoparticles are shown to have a hexagonal phase by XRD examination. The results of the FT‐IR analysis proved that specific chemical bonds exist in the ZnO, Co−ZnO, and AC−Co‐doped ZnO nanocomposites. FE‐SEM images revealed spherical morphology with aggregated, randomly distributed particles with an average size range of ZnO, Co−ZnO and AC−Co−ZnO are 59.55, 42.55, 41.16 nm. The band gap energies of ZnO, Co ‐ZnO, and AC−Co‐ ZnO, are found to be 3.10, 2.57, and 1.94 eV, respectively. Rhodamine B is used as a model contaminant to assess the samples under UV‐light driven photocatalytic effectiveness. The photocatalytic degradation efficiency (%) of the pristine ZnO, Co‐doped ZnO, and AC−Co‐doped ZnO catalysts are increased to 61.76, 74.86, and 91.46 % after 140 minutes of under UV‐light irradiation. Degradation rate constant (k) of the AC−Co−ZnO photocatalyst is found to be greater than that of pristine ZnO and Co−ZnO. Due to the synergistic effect of the AC and Co metal dopants and the spherical morphology of the AC−Co−ZnO sample, which boosted UV‐visible light absorption with reduced charge carrier recombination, resulting in outstanding photocatalytic activity. The study also investigated the bioactive effect of the samples on six bacterial species, revealing that the AC−Co‐doped ZnO nanocomposite has the most enhanced inhibitory effects against gram‐positive and gram‐negative bacteria. Consequently, medical wound dressing materials which helps to promote early healing by preventing microbial contamination.

Design of highly stable Co3O4/RGO/CoFe2O4 hybrid nanocomposites with multiple nanointerfaces for enhanced supercapacitor performance

In this study, we developed a novel hybrid electrode nanomaterial composed of Co3O4, CoFe2O4, and reduced graphene oxide (RGO) for electrochemical supercapacitor applications. The hybrid nanocomposite of Co3O4/RGO/CoFe2O4 was prepared using a modified chemical oxidation process and the phase formation of the composites was evidenced by X-ray diffraction (XRD). The grain size for Co3O4 and CoFe2O4 was estimated as 12 nm and 22 nm. For Co3O4/CoFe2O4 the reduced grain size of 19 nm for CoFe2O4 was observed and further it was reduced with RGO up to 15 nm. The bare Co3O4 exhibited a hexagonal plate-like morphology, whereas the bare CoFe2O4 showed mostly a spherical morphology. The reduced saturation magnetization for the hybrid electrode material due to the non-magnetic fraction of Co3O4 and RGO was observed to be 21 emu/g compared to the bare CoFe2O4 (77 emu/g). The Co3O4/RGO/CoFe2O4 electrode exhibited enriched electroactive sites and enhanced diffusion pathways, achieving a high specific capacity of 235C g − 1 at 5 A g − 1 with excellent durability.. This work highlights the significant charge storage potential of the Co3O4/RGO/CoFe2O4 hybrid, making it a promising candidate for advanced energy storage systems.

Poly(l-proline)-Stabilized Polypeptide Nanostructures via Ring-Opening Polymerization-Induced Self-Assembly (ROPISA).

Poly(proline) II helical motifs located at the protein-water interface stabilize the three-dimensional structures of natural proteins. Reported here is the first example of synthetic biomimetic poly(proline)-stabilized polypeptide nanostructures obtained by a straightforward ring-opening polymerization-induced self-assembly (ROPISA) process through consecutive N-carboxyanhydride (NCA) polymerization. It was found that the use of multifunctional 8-arm initiators is critical for the formation of nanoparticles. Worm-like micelles as well as spherical morphologies were obtained as confirmed by dynamic light scattering (DLS), transmission electron microscopy (TEM), and small angle X-ray scattering (SAXS). The loading of the nanostructures with dyes is demonstrated. This fast and open-vessel procedure gives access to amino acids-based nanomaterials with potential for applications in nanomedicine.

Se-functionalized ZIF-8 nanoparticles: synthesis, characterization and disruption of biofilms and quorum sensing in Serratia marcescens

The majority of research on nanomaterials has been concentrated on metal nanoparticles since they are easily made and manipulated. Nanomaterials have shown a wide range of applications in biology. Nevertheless, their bioactivity declines due to their extreme susceptibility to and novel Se@ZIF-8 by chemical method. The sizes and morphologies of Se (0) and Se@ZIFchemical and physical stimuli. The goal of encapsulating these nanomaterials in a matrix is gradually being pursued, which boosts their affordability, stability, and usability. Metal-organic frameworks, often known as MOFs, have the potential to be the best platforms for encapsulating metal nanoparticles due to their well-defined frameworks, persistent porosity, and flexibility in modification. In this investigation, we report the synthesis and optimization of polyvinylpyrrolidone-stabilized Se(0) nanoparticles -8 were affected by the ratios of Se/Zn2+and [hmim]/Zn2+used. The optimized Se@ZIF-8 nanoparticles exhibited a particle size and zeta potential of 319 nm and -34 mv respectively. Transmission electron microscopy displayed spherical morphology for Se(0) nanoparticles, whereas the surface morphology of novel Se@ZIF-8 nanoparticles was drastically changed to hexagonal shaped structures with smooth surface morphologies in scanning electron microscopy (SEM). The DTA, TG/DTG, XRD analysis confirmed the presence of novel Se incorporated ZIF-8 nanoparticulate framework. The synthesized novel Se@ZIF-8 nanoparticles showed efficient antibacterial activity as evidenced by low MIC values. Interestingly, these Se@ZIF-8 NPs not only inhibited biofilm formation inS. marcescens,but also effectively eradicated mature biofilms by degrading the eDNA of the EPS layer. It was validated by confocal laser scanning microscopy and SEM analysis. It was observed that Se@ZIF-8 targeted the Quroum Sensing pathway and reduced its associated virulence factors production. This work opens up a different approach of Se@ZIF-8 nanoparticles as novel antibiotics to treat biofilm-associated infections caused byS. marcescensand offer a solution for antimicrobial resistance.

Synergistic Photocatalysis by α-MoO3 Nanostructures and SWCNT Nanocomposites for Efficient Cross-Linking and Oxidative Degradation of Polystyrene Nanoplastics.

Nanoplastics (NPs) generated from plastic debris weathering pose a significant threat to ecosystems. The ubiquity of plastics driven by their advantageous physical properties, necessitates the development of efficient degradation and removal methods. Polystyrene (PS), a common and hazardous aquatic NP is a long-chain hydrocarbon with alternating phenyl groups. This study investigates the photooxidative degradation of PS NPs under UV light irradiation using synthesized MoO3 nanoflakes, nanobelts, and MoO3/SWCNT nanocomposites. Raman spectroscopy, X-ray diffraction, atomic force microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray, Brunauer-Emmett-Teller, and UV-vis spectroscopy were employed to characterize the photocatalyst. Field emission scanning electron microscopy was used to visualize morphological changes in the spherical PS NPs upon interaction with the photocatalysts. MoO3 nanoflakes acting as a photocatalyst under UV irradiation for 24 h achieved an impressive degradation efficiency exceeding 19%. This treatment significantly reduced the average diameter of PS NPs from 220 to 178 nm. Notably, even higher degradation efficiencies were observed with MoO3 nanobelts and nanocomposites as a complete change in the spherical morphology of PS NPs is observed. Fourier transform infrared spectroscopy elucidated the chemical transformations of PS during degradation. The observed changes in PS NPs structure due to photocatalytic oxidation at different time intervals indicate a promising approach.

Response Properties of Electrorheological Composite Hydrophilic Elastomers Based on Different Morphologies of Magnesium-Doped Strontium Titanate.

As smart materials, electrorheological elastomers (EREs) formed by pre-treating active electrorheological particles are attracting more and more attention. In this work, four Mg-doped strontium titanate (Mg-STO) particles with spherical, dendritic, flake-like, and pinecone-like morphologies were obtained via hydrothermal and low-temperature co-precipitation. XRD, SEM, Raman, and FT-IR were used to characterize these products. The results showed that Mg-STOs are about 1.5-2.0 μm in size, and their phase structures are dominated by cubic crystals. These Mg-STOs were dispersed in a hydrogel composite elastic medium. Then, Mg-STO/glycerol/gelatin electrorheological composite hydrophilic elastomers were obtained with or without an electric field. The electric field response properties of Mg-doped strontium titanate composite elastomers were investigated. We concluded that dendritic Mg-STO composite elastomers are high-performance EREs, and the maximum value of their energy storage was 8.70 MPa. The significant electrorheological performance of these products is helpful for their applications in vibration control, force transducers, smart structures, dampers, and other fields.

Preparation of BN Nanoparticle with High Sintering Activity and Its Formation Mechanism.

Hexagonal boron nitride (h-BN) nanoparticles have attracted increasing attention due to their unique structure and properties. However, it is difficult to synthesize h-BN nanoparticles with uniform spherical morphology due to their crystal characteristic. The morphology control by tuning their precursor synthesis is a promising and effective strategy to solve this problem. Especially, the treatment temperature of precursors plays an important role in the morphology and surface area of h-BN nanoparticles. Herein, h-BN nanoparticles with different morphologies were synthesized via regulating the treatment temperature of precursors. The result shows that treatment temperature will affect the microstructure and state of precursor and further influence the morphology of h-BN products. Benefiting from the unique structure, the h-BN obtained using 250 °C precursors shows higher specific surface area (61.1 m2 g-1) than that of 85 °C (36.5 m2 g-1) and 145 °C (27.9 m2 g-1). h-BN products obtained using 250 °C precursors show higher specific surface area than that of 85 °C and 145 °C. The optimal condition for obtaining high-quality spherical h-BN is the pretreatment temperature of 250 °C and sintering temperature of 1300 °C. Importantly, compared with commercial h-BN nanoparticles, the synthesized h-BN nanoparticles show more uniform structure and larger specific surface area, indicating that sintering activity will be greatly improved. Furthermore, the reaction pathway and formation mechanism of h-BN was revealed by DFT calculations. The result shows that the five stationary states and five transition states exist in the reaction pathway, and the energy barrier can be overcome at high temperatures to form a ring h-BN. In view of its simplicity and efficiency, this work is promising for designing and guiding the synthesis of h-BN nanoparticles with uniform morphology.