scholarly journals Solvent-Free Fabrication of Biphasic Lipid-Based Microparticles with Tunable Structure

Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 54
Author(s):  
Serena Bertoni ◽  
Beatrice Albertini ◽  
Joanna Ronowicz-Pilarczyk ◽  
Natalia Calonghi ◽  
Nadia Passerini
Keyword(s):  
Internal Structure ◽  
Chemical Properties ◽  
Cost Effective ◽  
Solvent Free ◽  
Spherical Particles ◽  
Lipid Phase ◽  
Composition And Structure ◽  
Ft Ir ◽  
Tunable Structure ◽  
Shell Particles

Lipid-based biphasic microparticles are generally produced by long and complex techniques based on double emulsions. In this study, spray congealing was used as a solvent-free fabrication method with improved processability to transform water-in-oil non-aqueous emulsions into spherical solid lipid-based particles with a biphasic structure (b-MPs). Emulsions were prepared by melt emulsification using different compositions of lipids (Dynasan®118 and Compritol®888 ATO), surfactants (Cetylstearyl alcohol and Span®60) and hydrophilic carriers (PEGs, Gelucire®48/16 and Poloxamer 188). First, pseudo-ternary phase diagrams were constructed to identify the area corresponding to each emulsion type (coarse emulsion or microemulsion). The hydrophobicity of the lipid mostly affected the interfacial tension, and thus the microstructure of the emulsion. Emulsions were then processed by spray congealing and the obtained b-MPs were characterized in terms of thermal and chemical properties (by DSC and FT-IR), external and internal morphology (by SEM, CLSM and Raman mapping). Solid free-flowing spherical particles (main size range 200–355 µm) with different architectures were successfully produced: microemulsions led to the formation of particles with a homogeneous internal structure, while coarse emulsions generated “multicores-shell” particles consisting of variable size hydrophilic cores evenly distributed within the crystalline lipid phase. Depending on their composition and structure, b-MPs could achieve various release profiles, representing a more versatile system than microparticles based on a single lipid phase. The formulation and technological strategy proposed, provides a feasible and cost-effective way of fabricating b-MPs with tunable internal structure and release behavior.

scholarly journals Antioxidant activity and green synthesis of selenium nanoparticles using allium sativum extract

2017 ◽  
Vol 9 (4) ◽  
pp. 634 ◽  
Author(s):  
Jay Vyas ◽  
Shafkat Rana
Keyword(s):  
Green Synthesis ◽  
Cost Effective ◽  
Selenium Nanoparticles ◽  
Spherical Particles ◽  
Frap Assay ◽  
Environment Friendly ◽  
Synthesis Of Nanoparticles ◽  
Transmission Electron ◽  
Ft Ir ◽  
Uv Visible

<p><strong>Abstract</strong></p><p>The green synthesis of nanoparticles has provided cost effective, environment friendly procedure and raising safe strategies for synthesis of non-materials. In this study we investigated the clove of <em>Allium sataivum</em>, which is used for the synthesis of Selenium nanoparticles. The biosynthesized selenium nanoparticles were characterized by using UV-Visible (UV-VIS) spectrophotometer, Transmission electron microscopy (TEM), Fourier transform spectroscopy (FT-IR) and Energy dispersive X-Ray spectroscopy (EDAX). The selenium nanoparticles synthesized by garlic were observed as hollow and spherical particles in size ranging 7-45nm which is found more stable more than two months. The present study also reports the efficiency of ABTS, DPPH and FRAP assay to estimate the antioxidant potential of selenium nanoparticles which synthesized by garlic extract.</p><p> </p>

scholarly journals Three-dimensional composite nanomaterials based on opal matrixes for electronic devices.

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
A.F. Belyanin ◽  
◽  
A.S. Bagdasaryan ◽  
S.A. Bagdasaryan ◽  
E.R. Pavlyukova ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Chemical Properties ◽  
Spherical Particles ◽  
Composite Nanomaterials ◽  
Opal Matrix ◽  
Amorphous Sio2 ◽  
Preparation Conditions ◽  
Composition And Structure ◽  
Other Substances ◽  
Rfbr Grant

he effect of preparation conditions on the composition and structure of three-dimensional composite nanomaterials based on opal matrixes (packing of spherical particles of amorphous SiO2) has been studied. The experimental part of the work was performed with the samples of opal matrixes with a diameter of spherical SiO2 particles equal ~260 nm. Composite nanomaterials were formed by repeatedly filling of opal matrixes with solutions of metal salts (oxides) and holding the samples at 623–723 K, and after that, they were annealed at 973–1473 K. Chemical reactions and phase transformations of substances in nanopores of opal matrixes depended on the annealing parameters, and chemical properties of intermediate compounds. There was confirmed the formation of SiO2 crystallites in nanopores of composite nanomaterials, as well as the products of their interaction with SiO2. Composite nanomaterials with filling of opal matrix nanopores with metals, ferroelectrics and piezoelectrics, multiferroic and other substances have been obtained. The resulting composite nanomaterials had ordered components (substances) with a given composition and crystallite size in the range of 10–90 nm. The influence of the composition and structure of composite nanomaterials containing ferromagnetically ordered nanostructured magnetic orthovanadates of rare-earth metals, Ni-Zn-Fe-, Co-Zn-Fe-spinel, and also Co and Ni together, on their properties was demonstrated. Present research was executed under financial support by RFBR (Grant N 18-29-02076).

Light- or Dark-Colored, L-DOPA-Based Melanins

2018 ◽  
Author(s):  
Koen Vercruysse ◽  
Margaret M. Whalen
Keyword(s):  
Human Physiology ◽  
Ir Spectra ◽  
Immune Cells ◽  
Chemical Properties ◽  
Chemical Signature ◽  
Ft Ir

<p>This report is a continuation of previous research on the H<sub>2</sub>O<sub>2</sub>-mediated synthesis of melanin-like pigments. We synthesized and characterized L-DOPA-based pigments using air- or H<sub>2</sub>O<sub>2</sub>-mediated<sub> </sub>oxidation. We compared their physic-chemical properties and evaluated their capacity to affect the interleukin release from immune cells. The use of higher concentrations of H<sub>2</sub>O<sub>2</sub> resulted in melanin-like materials with a distinct chemical signature in their FT-IR spectra and a lighter color. All pigments enhanced the interleukin release from immune cells. The possibility that lighter-colored melanins can be generated is discussed in the context of the importance of melanin-based pigmentation in human physiology.</p>

scholarly journals Bi2O3 nano-flakes as a cost-effective antibacterial agent

2021 ◽  
Author(s):  
Luke D Geoffrion ◽  
David Medina Cruz ◽  
Matthew Kusper ◽  
Sakr Elsaidi ◽  
Fumiya Watanabe ◽  
...  
Keyword(s):  
Bismuth Oxide ◽  
Antibacterial Agent ◽  
Chemical Properties ◽  
Cost Effective ◽  
Bismuth Compound ◽  
Photo Catalysis ◽  
Physico Chemical

Bismuth oxide is an important bismuth compound having applications in electronics, photo-catalysis and medicine. At the nanoscale, bismuth oxide experiences a variety of new physico-chemical properties because of its increased...

scholarly journals Fatty Acid Prediction in Bovine Milk by Attenuated Total Reflection Infrared Spectroscopy after Solvent-Free Lipid Separation

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1054
Author(s):  
Christopher Akhgar ◽  
Vanessa Nürnberger ◽  
Marlene Nadvornik ◽  
Margit Velik ◽  
Andreas Schwaighofer ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Milk Fat ◽  
Regression Models ◽  
Bovine Milk ◽  
Attenuated Total Reflection ◽  
Solvent Free ◽  
Novel Approach ◽  
Whole Milk ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

In the present study, a novel approach for mid-infrared (IR)-based prediction of bovine milk fatty acid composition is introduced. A rapid, solvent-free, two-step centrifugation method was applied in order to obtain representative milk fat fractions. IR spectra of pure milk lipids were recorded with attenuated total reflection Fourier-transform infrared (ATR-FT-IR) spectroscopy. Comparison to the IR transmission spectra of whole milk revealed a higher amount of significant spectral information for fatty acid analysis. Partial least squares (PLS) regression models were calculated to relate the IR spectra to gas chromatography/mass spectrometry (GC/MS) reference values, providing particularly good predictions for fatty acid sum parameters as well as for the following individual fatty acids: C10:0 (R2P = 0.99), C12:0 (R2P = 0.97), C14:0 (R2P = 0.88), C16:0 (R2P = 0.81), C18:0 (R2P = 0.93), and C18:1cis (R2P = 0.95). The IR wavenumber ranges for the individual regression models were optimized and validated by calculation of the PLS selectivity ratio. Based on a set of 45 milk samples, the obtained PLS figures of merit are significantly better than those reported in literature using whole milk transmission spectra and larger datasets. In this context, direct IR measurement of the milk fat fraction inherently eliminates covariation structures between fatty acids and total fat content, which poses a common problem in IR-based milk fat profiling. The combination of solvent-free lipid separation and ATR-FT-IR spectroscopy represents a novel approach for fast fatty acid prediction, with the potential for high-throughput application in routine lab operation.

scholarly journals Bimetallic Nanocrystals: Structure, Controllable Synthesis and Applications in Catalysis, Energy and Sensing

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1926
Author(s):  
Gaojie Li ◽  
Wenshuang Zhang ◽  
Na Luo ◽  
Zhenggang Xue ◽  
Qingmin Hu ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Chemical Properties ◽  
Research Progress ◽  
Synthesis Methods ◽  
Controlled Synthesis ◽  
Controllable Synthesis ◽  
Composition And Structure ◽  
Bimetallic Nanocrystals ◽  
Physical And Chemical ◽  
And Chemical Properties

In recent years, bimetallic nanocrystals have attracted great interest from many researchers. Bimetallic nanocrystals are expected to exhibit improved physical and chemical properties due to the synergistic effect between the two metals, not just a combination of two monometallic properties. More importantly, the properties of bimetallic nanocrystals are significantly affected by their morphology, structure, and atomic arrangement. Reasonable regulation of these parameters of nanocrystals can effectively control their properties and enhance their practicality in a given application. This review summarizes some recent research progress in the controlled synthesis of shape, composition and structure, as well as some important applications of bimetallic nanocrystals. We first give a brief introduction to the development of bimetals, followed by the architectural diversity of bimetallic nanocrystals. The most commonly used and typical synthesis methods are also summarized, and the possible morphologies under different conditions are also discussed. Finally, we discuss the composition-dependent and shape-dependent properties of bimetals in terms of highlighting applications such as catalysis, energy conversion, gas sensing and bio-detection applications.

Comparative characterisation of two fulvic acids from East Lake and Liangzi Lake in central China

2015 ◽  
Vol 12 (2) ◽  
pp. 189 ◽  
Author(s):  
Jun Wang ◽  
Huijie Li ◽  
Yong Chen ◽  
Yuan Fang ◽  
Zongping Wang ◽  
...  
Keyword(s):  
Fluorescence Spectroscopy ◽  
Cost Effective ◽  
Fulvic Acids ◽  
Central China ◽  
Anthropogenic Activity ◽  
Cost Effective Method ◽  
Vis Spectroscopy ◽  
East Lake ◽  
Ft Ir ◽  
Eem Fluorescence

Environmental context Fulvic acids account for a large proportion of dissolved organic matter in aquatic environments and affect the transportation and bioavailability of organic and inorganic pollutants. The structural and spectroscopic characteristics of fulvic acids mainly depend on the sources, seasons and anthropogenic activity. We present an advanced approach using fluorescence spectroscopy as a rapid and cost-effective method to investigate the composition, properties and origins of fulvic acids. Abstract Fulvic acids (FAs) isolated seasonally from the sediments of East Lake and Liangzi Lake in central China were comparatively investigated. The structural features of the FAs were characterised using chemical and spectroscopic methods, including elemental analysis, UV-Vis spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, and three-dimensional excitation emission matrix (EEM) fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC). The O/C, (O+N)/C and C/N ratios of FA extracted from Liangzi Lake (FAL) were higher than those of FA extracted from East Lake (FAE), indicating higher oxygen-containing functionality and polarity and less nutrient in FAL compared with FAE. The two FAs had similar UV-Vis spectra with different absorbance intensities. The FT-IR spectra showed that the two FAs had similar functional groups. The total fluorescence intensity and aromaticity of samples from Liangzi Lake were higher than those of East Lake except for those taken in the summer. The two FAs were largely terrestrially derived organic materials. Five fluorescent components, including four humic-like and two fulvic-like components, were identified by PARAFAC modelling of the EEM spectral data. The fluorescence was dominated by two components. The findings suggest that EEM fluorescence spectroscopy together with PARAFAC is a rapid and cost-effective method for understanding the characteristics and origins of FAs in natural water systems.

scholarly journals Synthesis and Conductivity Studies of Poly(Methyl Methacrylate) (PMMA) by Co-Polymerization and Blending with Polyaniline (PANi)

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1939
Author(s):  
Helyati Abu Hassan Shaari ◽  
Muhammad Mahyiddin Ramli ◽  
Mohd Nazim Mohtar ◽  
Norizah Abdul Rahman ◽  
Azizan Ahmad
Keyword(s):  
Methyl Methacrylate ◽  
Mechanical Stability ◽  
Chemical Properties ◽  
Cost Effective ◽  
Poly Methyl Methacrylate ◽  
Conducting Materials ◽  
Potential Applications ◽  
Polymerization Condition ◽  
Physical And Chemical ◽  
And Chemical Properties

Poly(methyl methacrylate) (PMMA) is a lightweight insulating polymer that possesses good mechanical stability. On the other hand, polyaniline (PANi) is one of the most favorable conducting materials to be used, as it is easily synthesized, cost-effective, and has good conductivity. However, most organic solvents have restricted potential applications due to poor mechanical properties and dispersibility. Compared to PANi, PMMA has more outstanding physical and chemical properties, such as good dimensional stability and better molecular interactions between the monomers. To date, many research studies have focused on incorporating PANi into PMMA. In this review, the properties and suitability of PANi as a conducting material are briefly reviewed. The major parts of this paper reviewed different approaches to incorporating PANi into PMMA, as well as evaluating the modifications to improve its conductivity. Finally, the polymerization condition to prepare PMMA/PANi copolymer to improve its conductivity is also discussed.

A High Resolution Simulation of a Single Shock-Accelerated Particle

2021 ◽  
Author(s):  
W. Curtis Maxon ◽  
Tanner Nielsen ◽  
Nicholas Denissen ◽  
Johnathan D. Regele ◽  
Jacob McFarland
Keyword(s):  
Flow Field ◽  
Cost Effective ◽  
Pressure Effects ◽  
Heat Diffusion ◽  
Spherical Particles ◽  
Navier Stokes ◽  
Exact Equation ◽  
Arbitrary Lagrangian Eulerian ◽  
Particle Laden Flows ◽  
Drag Models

Abstract Particle drag models, which capture macro viscous and pressure effects, have been developed over the years for various flow regimes to enable cost effective simulations of particle-laden flows. The relatively recent derivation by Maxey and Riley has provided an exact equation of motion for spherical particles in a flow field based on the continuum assumption. Many models that have been simplified from these equations have provided reasonable approximations; however, the sensitivity of particle-laden flows to particle drag requires a very accurate model to simulate. To develop such a model, a 2D axisymmetric Navier-Stokes direct numerical simulation of a single particle in a transient, shock-driven flow field was conducted using the hydrocode FLAG. FLAG's capability to run arbitrary Lagrangian-Eulerian hydrodynamics coupled with solid mechanic models makes it an ideal code to capture the physics of the flow field around and in the particle as it is shock-accelerated -- a challenging regime to study. The goal of this work is twofold: to provide a validation for FLAG's Navier-Stokes and heat diffusion solutions, and to provide a rationale for recent experimental particle drag measurements.

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