Morphology and Degradation of Multicompartment Microparticles Based on Semi-Crystalline Polystyrene-block-Polybutadiene-block-Poly(L-lactide) Triblock Terpolymers

The confinement assembly of block copolymers shows great potential regarding the formation of functional microparticles with compartmentalized structure. Although a large variety of block chemistries have already been used, less is known about microdomain degradation, which could lead to mesoporous microparticles with particularly complex morphologies for ABC triblock terpolymers. Here, we report on the formation of triblock terpolymer-based, multicompartment microparticles (MMs) and the selective degradation of domains into mesoporous microparticles. A series of polystyrene-block-polybutadiene-block-poly(L-lactide) (PS-b-PB-b-PLLA, SBL) triblock terpolymers was synthesized by a combination of anionic vinyl and ring-opening polymerization, which were transformed into microparticles through evaporation-induced confinement assembly. Despite different block compositions and the presence of a crystallizable PLLA block, we mainly identified hexagonally packed cylinders with a PLLA core and PB shell embedded in a PS matrix. Emulsions were prepared with Shirasu Porous Glass (SPG) membranes leading to a narrow size distribution of the microparticles and control of the average particle diameter, d ≈ 0.4 µm–1.8 µm. The core–shell cylinders lie parallel to the surface for particle diameters d < 0.5 µm and progressively more perpendicular for larger particles d > 0.8 µm as verified with scanning and transmission electron microscopy and particle cross-sections. Finally, the selective degradation of the PLLA cylinders under basic conditions resulted in mesoporous microparticles with a pronounced surface roughness.

Direct Synthesis of Titanium Nanoparticles by Induction Flow Levitation Technique

The paper considers the technology of obtaining metal nanoparticles by the method of induction levitation. A bulk metal sample of titanium with a purity of 99.9% and a mass of 0.4 g, which was heated and held in a state of flux levitation by a high-frequency electromagnetic field, was used as the basic raw material for nanoparticles. The obtained nanoparticles were examined using Х-ray diffraction analysis to determine the purity of the product. The analysis showed that it is high. Particle size distribution was investigated using dynamic light scattering, where the average particle diameter is 55 and 47 nm, obtained in Ar and He, respectively. The morphology was studied using scanning electron microscopy, according to which the average diameter of the particles synthesized with He and Ar is 45 and 57 nm, respectively.

Piezoelectric Current Generator Based on Bismuth Ferrite Nanoparticles

Bismuth ferrite nanoparticles with an average particle diameter of 45 nm and spatial symmetry R3c were obtained by combustion of organic nitrate precursors. BiFeO3-silicone nanocomposites with various concentrations of nanoparticles were obtained by mixing with a solution of M10 silicone. Models of piezoelectric generators were made by applying nanocomposites on a glass substrate and using aluminum foil as contacts. The thickness of the layers was about 230 μm. There was a proportional relationship between the different concentrations of nanoparticles and the detected potential. The output voltages were 0.028, 0.055, and 0.17 V with mass loads of 10, 30, and 50 mass%, respectively.

A facile hydrothermal method to synthesize fluorescent carbon dots for detecting iron

A new carbon source (mint) is proposed to prepare carbon dots with excellent photostability and strong photobleaching properties by one-step hydrothermal method. The average particle diameter for carbon dots is 5.0 nm, emitting blue luminescence, and the quantum yield is 4.5%. Fluorescence can be obviously quenched in Fe3+ solution. Further, A method based on fluorescence quenching of carbon dots for detecting Fe3+ is established, which has a linear range of 0.5∼100 μM with a detection limit of 0.104 μM. This may provide an easy and sensitive method for iron detection.

OPTIMIZATION OF MICROENCAPSULATION CONDITIONS OF TULIP PETAL ANTHOCYANIN: STORAGE STABILITY TEST

In this study, anthocyanins from tulip petals were extracted and encapsulated by a spray drier. The novelty of this study is the first attempt in a production of natural colorant from tulip petal and its application in food model system. Encapsulation efficiency of the sample ranged from 93.06 % to 97.07% and, optimum temperature and maltodextrin ratio were 135 °C and 3/1, respectively. The sample prepared at optimum condition showed uniform distribution and had no crack with an average particle diameter of 5.55 m. A significant change in a* values was observed at a temperature of 40 °C during storage. Half-life value (t1/2) of the anthocyanin degradation was found as 391.5 and 16.69 days for 4 °C and 40 °C respectively. This study suggested that tulip petal anthocyanin can be used as a food colorant in samples subjected to low or mild heat application.

Effect of Particle Size Distributions on Minimum Fluidization Velocity with Varying Gas Temperature

The particle size distribution (PSD) is an important property that can influence the hydrodynamics and chemical conversion in fluidized bed system. The objective of this study is to investigate the effect of PSDs of particle and gas temperature on minimum fluidization velocity (Umf). Here, the silica sand with three average diameters and five PSDs including narrow cut, Gaussian, Gaussian with high standard deviation, negative skewed distribution and positive skewed distribution were used. The considered gas temperature ranged from 30 to 120 °C. The results showed that the Umf values with wide PSDs were lower than the Umf values for narrow cut particle with the same average diameter. The reason can be explained by the addition of smaller particle will improve the fluidization characteristics. The standard deviation and skewness of PSD also influenced on the Umf. The Umf was observed to decrease with increasing gas temperature. In addition, the effect of average particle diameter could also be seen. The Umf increased with the increasing of average particle diameter.

Application of Colloidal Dispersions of Bioshell Calcium Oxide (BiSCaO) for Disinfection

Bioshell calcium oxide (BiSCaO) is a scallop-shell powder heated at a high temperature. BiSCaO is composed mainly of calcium oxide and exhibits broad microbicidal properties. The aim of this study is to evaluate the disinfection and decontamination abilities of BiSCaO colloidal dispersions with that of commercially available bioshell calcium hydroxide (BiSCa(OH)2) following the formation of flocculants/precipitates under strongly alkaline conditions (pH 11.5–12.2). Various concentrations of BiSCaO and BiSCa(OH)2 colloidal dispersions were prepared by mixing with Na-polyPO4 (PP) and Na-triPO4 (TP) as flocculating agents. The microbicidal activities, and the degree of flocculation/precipitation of trypan blue, albumin, chondroitin sulfate, heparin, non-anticoagulant heparin carrying polystyrene (NAC-HCPS), and low-molecular-weight heparin/protamine nanoparticles (LMWH/P NPs) were dependent on the pH, the average particle diameter, and the concentration of BiSCaO or BiSCa(OH)2 and of the phosphate compound. BiSCaO (average particle diameter: 6 μm) colloidal dispersions (0.2 wt.%) containing 0.15 wt.% PP or TP exhibited substantially stronger microbicidal activity and flocculation/precipitation under strongly alkaline conditions. These results suggest that BiSCaO colloidal dispersions together with phosphate compounds have practical applicability for disinfection.

Preparation and pharmacokinetics of cefquinome sulfate liposomes in goats

We evaluated the pharmacokinetics of cefquinome sulfate (CEF) liposomes in eight healthy goats following intramuscular administration at 4 mg/kg. The average particle diameter of CEF liposomes prepared by the ethanol injection method was 335nm with a CEF entrapment efficiency of 69.56%. The elimination half-life (t1/2b) of CEF liposomes was 33.04h compared with 16.21 h for CEF injected without carrier (p less than 0.05). The area under the concentration curve (AUC) for CEF liposomes was approximately three-times greater than for CEF alone (P less than 0.05). The time-point of maximum plasma concentration of the drug (Tp) and the maximum plasma concentration (Cmax) were 4.38 h and 1.99 ìg/mL for CEF liposomes, compared with 1.86 h and 3.55 ìg/mL for CEF without carrier, respectively.

STABILITY OF SYNTHESIZED SILVER NANOPARTICLES IN CITRATE AND MIXED GELATIN/CITRATE SOLUTION

The study focuses on an investigation of the influence of both citrate and mixed gelatin/citrate as a reductant and stabilizer on the colloidal stability of silver nanoparticles (AgNPs)synthesized by a chemical reduction of Ag⁺ ions after a short - (7th day) - and long - (118th day) - term storage. Formed AgNPs were characterized by a UV–vis Spectroscopy, Transmission Electron Microscope (TEM), Dynamic light scattering (DLS) and Zeta-potential (ZP). The obtained results revealed that a short-term stability of the synthesized AgNPs was greatly influenced by a citrate stabilizer with the absence of gelatin. Smaller-sized AgNPs (average particle diameter of 3 nm), roughly spherical in a shape, were obtained with a narrow size distribution. The very negative value of the Zeta-potential confirmed a strong stability of the citrate capped AgNPs. However, a surface coating of the AgNPs by a gelatin/citrate stabilizer was found to be a dominant contributor in improving a long-term stability of the AgNPs (average particle diameter of 26 nm). The use of gelatin in mixed stabilizer solution provided the AgNPs with higher monodispersity and a controllable size after both the short and long-term storage.