Characterization of β-cyclodextrin Self-Aggregates for Eugenol Encapsulation

2012 ◽  
Vol 8 (2) ◽  
Author(s):  
Ji-Yeon Chun ◽  
Sung-Kyu You ◽  
Mi-Yeon Lee ◽  
Mi-Jung Choi ◽  
Sang-Gi Min
Keyword(s):  
Relative Humidity ◽  
Self Assembly ◽  
Retention Rate ◽  
Thick Layer ◽  
Storage Duration ◽  
Aggregation Behaviour ◽  
Induced Decomposition ◽  
And Storage ◽  
Oxidation Loss

Abstract The application of β-cyclodextrin(CD)-assisted molecular encapsulation of neutraceutical ingredients, functional food in food products, hydrophobic drugs, and volatile substances helps protect the active ingredients against oxidation, loss of volatile compounds and light-induced decomposition and increases the solubility of hydrophobic medicines. Self-assembly aggregation of CDs has been extensively investigated from the aggregation of native CDs to high-order complex aggregates. The increasing complex order of the aggregates is dependent on some parameters such as pH, temperature, time and concentration. The aim of this study was to investigate the effects of the aggregation behaviour of β-cyclodextrin (CD)-eugenol complexes induced at shaking times on the release characteristic at various relative humidity and storage temperatures. The particle size started to increase after shaking for 8 h at 650 nm, and then, significant aggregation (1,110 nm) was observed after 24 h. The retention rate of eugenol significantly increased according to storage duration under various relative humidity and temperature conditions. Prolonged shaking time enhanced the self-aggregation of β-CD-eugenol complexes resulting in eugenol release behavior due to their effect on the aggregation mechanism, as assessed by TEM observation. The aggregation of β-CD-eugenol complexes could be attributed to the slow release of eugenol owing to the presence of a thick layer of β-CD aggregates.

scholarly journals Structural Characterization of an Archaeal Lipid Bilayer as a Function of Hydration and Temperature

2020 ◽  
Vol 21 (5) ◽  
pp. 1816
Author(s):  
Marta Salvador-Castell ◽  
Bruno Demé ◽  
Philippe Oger ◽  
Judith Peters
Keyword(s):  
Phase Transition ◽  
Relative Humidity ◽  
Lipid Bilayers ◽  
Self Assembly ◽  
Structural Characteristics ◽  
Scattering Length ◽  
Structural Parameters ◽  
Hydrophobic Region ◽  
Lamellar Phases

Archaea, the most extremophilic domain of life, contain ether and branched lipids which provide extraordinary bilayer properties. We determined the structural characteristics of diether archaeal-like phospholipids as functions of hydration and temperature by neutron diffraction. Hydration and temperature are both crucial parameters for the self-assembly and physicochemical properties of lipid bilayers. In this study, we detected non-lamellar phases of archaeal-like lipids at low hydration levels, and lamellar phases at levels of 90% relative humidity or more exclusively. Moreover, at 90% relative humidity, a phase transition between two lamellar phases was discernible. At full hydration, lamellar phases were present up to 70 °C and no phase transition was observed within the temperature range studied (from 25 °C to 70 °C). In addition, we determined the neutron scattering length density and the bilayer’s structural parameters from different hydration and temperature conditions. At the highest levels of hydration, the system exhibited rearrangements on its corresponding hydrophobic region. Furthermore, the water uptake of the lipids examined was remarkably high. We discuss the effect of ether linkages and branched lipids on the exceptional characteristics of archaeal phospholipids.

scholarly journals Characterization of the Casein/Keratin Self-Assembly Nanomicelles

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Su Xiao-Zhou ◽  
Wang Hong-Ru ◽  
Huang Mian
Keyword(s):  
Self Assembly ◽  
Storage Stability ◽  
Mass Ratio ◽  
Scanning Calorimetry ◽  
Uniform Size ◽  
Force Microscopy ◽  
Atomic Force ◽  
Good Potential ◽  
And Storage

Complex nanomicelles were made from casein and keratin through electrostatic self-assembly and transglutaminase fixation that was proved to be harmless and green. The complex nanomicelles were characterized by dynamic light scattering, scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and steady-state florescence. The results show that the complex nanomcelles acquired at the neutral pH in the mass ratio of casein to keratin 4 : 1 exhibit an anomalous sphere shape with uniform size which the diameter is about 40–70 nm. The complex nanomicelles in solution possess excellent dilution and storage stability due to the fixation and their highζ-potential (22.8 mV). The complex nanomicelles are relatively hydrophilic and have a good potential for industrial application.

scholarly journals XPS Investigation on Changes in UO2 Speciation following Exposure to Humidity

MRS Advances ◽  
2016 ◽  
Vol 1 (44) ◽  
pp. 2993-2997
Author(s):  
Scott B. Donald ◽  
M. Lee Davisson ◽  
Art J. Nelson
Keyword(s):  
Relative Humidity ◽  
Photoelectron Spectroscopy ◽  
Uranium Oxide ◽  
Accelerated Aging ◽  
X Ray ◽  
Uranium Oxidation ◽  
Powder Samples ◽  
Processing And Storage ◽  
And Storage

ABSTRACT High purity UO2 powder samples were subjected to accelerated aging under controlled conditions with relative humidity ranging from 34% to 98%. Characterization of the chemical speciation of the products was accomplished using X-ray photoelectron spectroscopy (XPS). A shift to higher uranium oxidation states was found to be directly correlated to increased relative humidity exposure. Additionally, the relative abundance of O2-, OH-, and H2O was found to vary with exposure time. Thus, it is expected that uranium oxide materials exposed to high relative humidity conditions during processing and storage would display a similar increase in average uranium valence.

Characterization of seawater reverse osmosis fouled membranes from large scale commercial desalination plant

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Reverse Osmosis ◽  
Large Scale ◽  
Retention Rate ◽  
Local Level ◽  
Microscopic Analysis ◽  
Transmembrane Pressure ◽  
Hydraulic Permeability ◽  
Seawater Reverse Osmosis ◽  
A Chain

The objective of this work is to study the ageing state of a used reverse osmosis (RO) membrane taken in Algeria from the Benisaf Water Company seawater desalination unit. The study consists of an autopsy procedure used to perform a chain of analyses on a membrane sheet. Wear of the membrane is characterized by a degradation of its performance due to a significant increase in hydraulic permeability (25%) and pressure drop as well as a decrease in salt retention (10% to 30%). In most cases the effects of ageing are little or poorly known at the local level and global measurements such as (flux, transmembrane pressure, permeate flow, retention rate, etc.) do not allow characterization. Therefore, a used RO (reverse osmosis) membrane was selected at the site to perform the membrane autopsy tests. These tests make it possible to analyze and identify the cause as well as to understand the links between performance degradation observed at the macroscopic scale and at the scale at which ageing takes place. External and internal visual observations allow seeing the state of degradation. Microscopic analysis of the used membranes surface shows the importance of fouling. In addition, quantification and identification analyses determine a high fouling rate in the used membrane whose foulants is of inorganic and organic nature. Moreover, the analyses proved the presence of a biofilm composed of protein.

scholarly journals Electrochemical Properties of Lipid Membranes Self-Assembled from Bicelles

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Damian Dziubak ◽  
Kamil Strzelak ◽  
Slawomir Sek
Keyword(s):  
Electrochemical Properties ◽  
Self Assembly ◽  
Lipid Membranes ◽  
Lipid Membrane ◽  
Membrane Resistance ◽  
Electrochemical Characteristics ◽  
Freeze Thaw ◽  
Lipid Films ◽  
Supported Lipid Membranes

Supported lipid membranes are widely used platforms which serve as simplified models of cell membranes. Among numerous methods used for preparation of planar lipid films, self-assembly of bicelles appears to be promising strategy. Therefore, in this paper we have examined the mechanism of formation and the electrochemical properties of lipid films deposited onto thioglucose-modified gold electrodes from bicellar mixtures. It was found that adsorption of the bicelles occurs by replacement of interfacial water and it leads to formation of a double bilayer structure on the electrode surface. The resulting lipid assembly contains numerous defects and pinholes which affect the permeability of the membrane for ions and water. Significant improvement in morphology and electrochemical characteristics is achieved upon freeze–thaw treatment of the deposited membrane. The lipid assembly is rearranged to single bilayer configuration with locally occurring patches of the second bilayer, and the number of pinholes is substantially decreased. Electrochemical characterization of the lipid membrane after freeze–thaw treatment demonstrated that its permeability for ions and water is significantly reduced, which was manifested by the relatively high value of the membrane resistance.

Characterization of an ORMOCER®-coated FBG sensor for relative humidity sensing

Measurement ◽  
2021 ◽  
Vol 171 ◽  
pp. 108851
Author(s):  
Jun-Yi Guo ◽  
Bin Shi ◽  
Meng-Ya Sun ◽  
Cheng-Cheng Zhang ◽  
Guang-Qing Wei ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Humidity Sensing ◽  
Fbg Sensor

2D Self-assembly and Electronic Characterization of Oxygen-Boron-Oxygen-Doped Chiral Graphene Nanoribbons

2021 ◽  
Author(s):  
Lei Jin ◽  
Nerea Bilbao ◽  
Yang Lv ◽  
Xiao-Ye Wang ◽  
Soltani Paniz ◽  
...  
Keyword(s):  
Edge Effects ◽  
Self Assembly ◽  
Quantum Confinement ◽  
Graphene Nanoribbons ◽  
One Dimensional ◽  
The Past ◽  
Different Types

Graphene nanoribbons (GNRs), quasi-one-dimensional strips of graphene, exhibit a nonzero bandgap due to quantum confinement and edge effects. In the past decade, different types of GNRs with atomically precise structures...

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