Influence of Poly(Vinylpyrrolidone) Capping Agent on the Synthesis of Silver Structures by Polyol Method

In this study, silver nano/micro structures were successfully synthesized from silver nitrate via a polyol method at 160 °C. In our synthesis route, ethylene glycol (EG) was used as both as solvent and reducing agent, and polyvinylpyrrolidone (PVP) with different molecular weight was employed as capping agent. When reduced the PVP’s molecular weight from 58000 to 8000, the spherical morphology of silver particles changed to rod shape. Moreover, by changing the injection method of PVP and controlling the reaction time, silver nanoparticles with uniform spherical morphology and size was prepared. The obtained silver nanoparticles were characterized by X-ray diffraction (XRD) and ultraviolet-visible spectrophotometry (UV-vis) which indicated the formation of nanoparticles. Scanning electron microscopy (SEM) contributed to the particle morphology and size analysis. The morphology and particle size of the resulting silver nanoparticles were depended on the PVP’s molecular weight and the injection method.

Liquid crystalline behavior and photoluminescence of lanthanide decanoate nanoparticles synthesized by microwave radiation

Luminescent lanthanide decanoate nanoparticles (LnC10 NPs; Ln = Pr, Nd, Sm, Eu, Gd, Er) with spherical morphology (<100 nm) have been synthesized via a facile microwave (MWV) method using Ln(NO3)3·xH2O, ethanol/water, and decanoic acid.

The Effect of Particle Size and Surface Roughness of Spray-Dried Bosentan Microparticles on Aerodynamic Performance for Dry Powder Inhalation

The purpose of this study was to prepare spray dried bosentan microparticles for dry powder inhaler and to characterize its physicochemical and aerodynamic properties. The microparticles were prepared from ethanol/water solutions containing bosentan using spray dryer. Three types of formulations (SD60, SD80, and SD100) depending on the various ethanol concentrations (60%, 80%, and 100%, respectively) were used. Bosentan microparticle formulations were characterized by scanning electron microscopy, powder X-ray diffraction, laser diffraction particle sizing, differential scanning calorimetry, Fourier-transform infrared spectroscopy, dissolution test, and in vitro aerodynamic performance using Andersen cascade impactor™ (ACI) system. In addition, particle image velocimetry (PIV) system was used for directly confirming the actual movement of the aerosolized particles. Bosentan microparticles resulted in formulations with various shapes, surface morphology, and particle size distributions. SD100 was a smooth surface with spherical morphology, SD80 was a rough surfaced with spherical morphology and SD60 was a rough surfaced with corrugated morphology. SD100, SD80, and SD60 showed significantly high drug release up to 1 h compared with raw bosentan. The aerodynamic size of SD80 and SD60 was 1.27 µm and SD100 was 6.95 µm. The microparticles with smaller particle size and a rough surface aerosolized better (%FPF: 63.07 ± 2.39 and 68.27 ± 8.99 for SD60 and SD80, respectively) than larger particle size and smooth surface microparticle (%FPF: 22.64 ± 11.50 for SD100).

Preparation of Spray-Dried Functional Food: Effect of Adding Bacillus clausii Bacteria as a Co-Microencapsulating Agent on the Conservation of Resveratrol

The effect of bacteria (Bacillus clausii) addition on the culturability and antioxidant activity of resveratrol prepared by spray drying was studied in this work. Inulin and lactose were employed as carrying agents and their performance compared. Resveratrol microencapsulated in inulin showed the highest antioxidant activity (26%) against free radicals. The co-encapsulated materials (bacteria and resveratrol) in inulin and lactose showed similar activities (21%, and 23%, respectively) suggesting that part of resveratrol was absorbed by the bacteria. Particles showed a regular spherical morphology with smooth surfaces, and size in the micrometer range (2–25 μm). The absence of bacteria in the SEM micrographs and the culturability activity suggested the preservation of the organisms within the micro and co-microencapsulated particles. The present work proposes the preparation of a functional food with probiotic and antioxidant properties.

Preparation of Nano-spherical Iron Phosphate by Hydrothermal Method and Its Application as the Precursor of Lithium Iron Phosphate

First, nano-spherical iron phosphate was prepared using the hydrothermal method. Then, the carbothermal reduction method was applied to synthesize the LiFePO4/C composite material capable of good carbon coating effect with the prepared nano-spherical iron phosphate as a precursor. By means of scanning electron microscope, transmission electron microscope, Zeta potentiometer, inductively coupled plasma spectrometer, X-ray diffraction, X-ray photoelectron spectroscopy, electrochemical testing, and other methods, the material was characterized and tested for its morphology, particle size, composition, structure, and electrochemical performance. According to the test results, when the initial mass concentration of Fe3+ in the reaction solution is 2%, the amount of N and S impurity is merely 19 and 27 ppm, respectively. In the meantime, particle size is small, with a range of roughly 50–100 nm, and a spherical morphology is shown. The synthesized LiFePO4/C retains its nano-spherical morphology, which leads to a desirable carbon coating effect and an excellent electrochemical performance. The first charge–discharge specific capacity at 0.1 C rate reached 163.7 and 161.4 mAh/g, the charge–discharge efficiency was 98.6%, and the capacity retention rate at 50 charge–discharge cycles at 1 C rate reached 98.52%.

Filamentous versus Spherical Morphology: A Case Study of the Recombinant A/WSN/33 (H1N1) Virus

Influenza A virus is a serious human pathogen that assembles enveloped virions on the plasma membrane of the host cell. The pleiomorphic morphology of influenza A virus, represented by spherical, elongated, or filamentous particles, is important for the spread of the virus in nature. Using fixative protocols for sample preparation and negative staining electron microscopy, we found that the recombinant A/WSN/33 (H1N1) (rWSN) virus, a strain considered to be strictly spherical, may produce filamentous particles when amplified in the allantoic cavity of chicken embryos. In contrast, the laboratory WSN strain and the rWSN virus amplified in Madin–Darby canine kidney cells exhibited a spherical morphology. Next-generation sequencing (NGS) suggested a rare Ser126Cys substitution in the M1 protein of rWSN, which was confirmed by the mass spectrometric analysis. No structurally relevant substitutions were found by NGS in other proteins of rWSN. Bioinformatics algorithms predicted a neutral structural effect of the Ser126Cys mutation. The mrWSN_M1_126S virus generated after the introduction of the reverse Cys126Ser substitution exhibited a similar host-dependent partially filamentous phenotype. We hypothesize that a shortage of some as-yet-undefined cellular components involved in virion budding and membrane scission may result in the appearance of filamentous particles in the case of usually “nonfilamentous” virus strains.

Thermoresponsive cationic dendronized copolymers and their corresponding nanogels as smart gene carriers

Thermoresponsive dendronized copolymer nanogels show unique condensation, protection and controlled release of siRNA due to dendritic topology and spherical morphology.

Direct Nitridation Synthesis of Quasi-Spherical β-Si3N4 Powders with CaF2 Additive

In this work, the quasi-spherical β-Si3N4 powders were synthesized via an efficient direct nitridation strategy with CaF2 as the catalytic material under NH3 atmosphere. The effect of CaF2 on phase composition and crystalline morphology was studied. CaF2 additive can accelerate the nitridation of silicon powders, and the particles of nitridation products tend to have an equiaxed structure with the CaF2 additive increasing. When 4 wt% CaF2 additive or more was added, submicron β-Si3N4 particles with quasi-spherical morphology and eminent crystal integrity were obtained. In contrast, irregular α-Si3N4 particles appear as the main phase with less than 4 wt% CaF2 additive. The growth mechanism of Si3N4 particles was also discussed. CaxSiyOz liquid phase is crucial in the nitridation of silicon powders with CaF2 additive.