scholarly journals Characterization of Nanoparticles Using DSPE-PEG2000 and Soluplus

2020 ◽  
Vol 4 (3) ◽  
pp. 28 ◽  
Author(s):  
Rina Takayama ◽  
Yutaka Inoue ◽  
Isamu Murata ◽  
Ikuo Kanamoto

The aim of this study was to evaluate the characterized hydration method to prepare nanoparticles using Soluplus, a block copolymer with amphipathic properties, and distearoyl phosphatidyl ethanolamine (DSPE)-PEG2000 owing to particle size distribution, zeta potential, particle stability, and transmission electron microscopy (TEM) observed and 31P-NMR spectra. The results showed that, in a suspension of DSPE-PEG2000 and Soluplus at a ratio of 1/1, the prepared microparticles were stable for five days in the dark and at 25 °C. It was also confirmed that the 1/1 suspension of DSPE-PEG2000/Soluplus was stable for five days under the same conditions with the magnesium chloride solution. TEM measurements confirmed the presence of micelle-like particles of 50 to 150 nm in the 1/1 ratio mix of DSPE-PEG2000/Soluplus. 31P-NMR spectral data confirmed that DPSE-PEG2000/Soluplus at mixing ratio of 1/1 has a strong intermolecular with the phosphate group, indicated by the fact that the peak shift and the full width at half maximum were the largest compared with DSPE-PEG2000 with the intermolecular interaction. On the basis of the findings of this study, we conclude that microparticles can be formed using DSPE-PEG2000 and Soluplus via the hydration method, and that the optimum weight ratio of DSPE-PEG2000 to Soluplus is 1/1.

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2787
Author(s):  
Cheng-Ho Chen ◽  
Ying-Chen Lin ◽  
Fu-Su Yen

Polyaniline doped with dodecylbenzenesulfonic acid/χ-aluminum oxide (PANDB/χ-Al2O3) conducting core-shell nanocomposites was synthesized via an in situ polymerization method in this study. PANDB was synthesized in the presence of dodecylbenzenesulfonic acid (DBSA), which functioned as a dopant and surfactant. The electrical conductivity of the conducting PANDB/χ-Al2O3 core-shell nanocomposite was approximately 1.7 × 10−1 S/cm when the aniline/χ-Al2O3 (AN/χ-Al2O3) weight ratio was 1.5. The transmission electron microscopy (TEM) results indicated that the χ-Al2O3 nanoflakes were thoroughly coated by PANDB to form the core-shell (χ-Al2O3-PANDB) structure. The TEM and field-emission scanning electron microscopy (FE-SEM) images of the conducting PANDB/χ-Al2O3 core-shell nanocomposites also indicated that the thickness of the PANDB layer (shell) could be increased as the weight ratio of AN/χ-Al2O3 was increased. In this study, the optimum weight ratio of AN/χ-Al2O3 was identified as 1.5. The conducting PANDB/χ-Al2O3 core-shell nanocomposite was then blended with water-based polyurethane (WPU) to form a conducting WPU/PANDB/χ-Al2O3 blend film. The resulting blend film has promising antistatic and electrostatic discharge (ESD) properties.


2008 ◽  
Vol 15 (05) ◽  
pp. 545-550 ◽  
Author(s):  
YIN-CUN ZHU ◽  
JI-SEN JIANG

α- Fe 2 O 3@ATO (antimony doped tin oxide) nanocomposite particles with core–shell structure were prepared by homogeneous precipitation method using monodispersed α- Fe 2 O 3 (hematite) nanoparticles as cores, SnCl 4 · 5 H 2 O and SbCl 3 as the precursor of the shell. The morphology and structure of the nanocomposite particles were studied with transmission electron microscopy and X-ray diffraction, respectively. The electricity properties of the nanocomposite were also investigated in terms of coating amount, molar ratio of element Sb to Sn , and heat treatment conditions. The results showed that the conditions of ATO/α- Fe 2 O 3 (weight ratio) = 70%, n( Sb )/n( Sn ) = 10%, calcined at 700°C for 1 h were optimal for the conductivity of the nanocomposite.


2020 ◽  
Author(s):  
Christopher Liu ◽  
Pei Ying Chen ◽  
Preston Dang ◽  
Michael Zhang ◽  
Andrew Kapinos ◽  
...  

ABSTRACTBacteriophages that infect Arthrobacter, a genus of bacteria which play key ecological roles in soil, warrant further study. A novel Actinobacteriophage, Giantsbane, was isolated on Arthrobacter globiformis and purified. Particle stability was tested at various temperatures and salinity concentrations by observing titer differences; unpaired Student’s t-tests revealed these differences to be insignificant. Transmission electron microscopy and Illumina whole-genome sequencing revealed that Giantsbane’s morphology and genome length, respectively, were characteristic of Siphoviridae phages. 94 putative open reading frames were determined using Glimmer, GeneMark, and manual review; none were associated with lysogeny. Giantsbane was placed into phage cluster AU, and SplitsTree and batch ANI analyses revealed similarities with other AU phages. The annotated genome was further analyzed using Phamerator and MEME-Suite, which identified repeated motifs present in several other phages. These findings help further our understanding of the physiological and genomic aspects of phage biology.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
T. C. Tisone ◽  
S. Lau

In a study of the properties of a Ta-Au metallization system for thin film technology application, the interdiffusion between Ta(bcc)-Au, βTa-Au and Ta2M-Au films was studied. Considered here is a discussion of the use of the transmission electron microscope(TEM) in the identification of phases formed and characterization of the film microstructures before and after annealing.The films were deposited by sputtering onto silicon wafers with 5000 Å of thermally grown oxide. The film thicknesses were 2000 Å of Ta and 2000 Å of Au. Samples for TEM observation were prepared by ultrasonically cutting 3mm disks from the wafers. The disks were first chemically etched from the silicon side using a HNO3 :HF(19:5) solution followed by ion milling to perforation of the Au side.


Author(s):  
Kemining W. Yeh ◽  
Richard S. Muller ◽  
Wei-Kuo Wu ◽  
Jack Washburn

Considerable and continuing interest has been shown in the thin film transducer fabrication for surface acoustic waves (SAW) in the past few years. Due to the high degree of miniaturization, compatibility with silicon integrated circuit technology, simplicity and ease of design, this new technology has played an important role in the design of new devices for communications and signal processing. Among the commonly used piezoelectric thin films, ZnO generally yields superior electromechanical properties and is expected to play a leading role in the development of SAW devices.


Author(s):  
O. L. Shaffer ◽  
M.S. El-Aasser ◽  
C. L. Zhao ◽  
M. A. Winnik ◽  
R. R. Shivers

Transmission electron microscopy is an important approach to the characterization of the morphology of multiphase latices. Various sample preparation techniques have been applied to multiphase latices such as OsO4, RuO4 and CsOH stains to distinguish the polymer phases or domains. Radiation damage by an electron beam of latices imbedded in ice has also been used as a technique to study particle morphology. Further studies have been developed in the use of freeze-fracture and the effect of differential radiation damage at liquid nitrogen temperatures of the latex particles embedded in ice and not embedded.Two different series of two-stage latices were prepared with (1) a poly(methyl methacrylate) (PMMA) seed and poly(styrene) (PS) second stage; (2) a PS seed and PMMA second stage. Both series have varying amounts of second-stage monomer which was added to the seed latex semicontinuously. A drop of diluted latex was placed on a 200-mesh Formvar-carbon coated copper grid.


Author(s):  
L.E. Murr ◽  
A.B. Draper

The industrial characterization of the machinability of metals and alloys has always been a very arbitrarily defined property, subject to the selection of various reference or test materials; and the adoption of rather naive and misleading interpretations and standards. However, it seems reasonable to assume that with the present state of knowledge of materials properties, and the current theories of solid state physics, more basic guidelines for machinability characterization might be established on the basis of the residual machined microstructures. This approach was originally pursued by Draper; and our presentation here will simply reflect an exposition and extension of this research.The technique consists initially in the production of machined chips of a desired test material on a horizontal milling machine with the workpiece (specimen) mounted on a rotary table vice. A single cut of a specified depth is taken from the workpiece (0.25 in. wide) each at a new tool location.


Author(s):  
D.M. Vanderwalker

Aluminum-lithium alloys have a low density and high strength to weight ratio. They are being developed for the aerospace industry.The high strength of Al-Li can be attributed to precipitation hardening. Unfortunately when aged, Al-Li aquires a low ductility and fracture toughness. The precipitate in Al-Li is part of a sequence SSSS → Al3Li → AlLi A description of the phases may be found in reference 1 . This paper is primarily concerned with the Al3Li phase. The addition of Zr to Al-Li is being explored to find the optimum in properties. Zirconium improves fracture toughness and inhibits recrystallization. This study is a comparision between two Al-Li-Zr alloys differing in Zr concentration.Al-2.99Li-0.17Zr(alloy A) and Al-2.99Li-0.67Zr (alloy B) were solutionized for one hour at 500oc followed by a water quench. The specimens were then aged at 150°C for 16 or 40 hours. The foils were punched into 3mm discs. The specimens were electropolished with a 1/3 nitric acid 2/3 methanol solution. The transmission electron microscopy was conducted on the JEM 200CX microscope.


Author(s):  
Julia T. Luck ◽  
C. W. Boggs ◽  
S. J. Pennycook

The use of cross-sectional Transmission Electron Microscopy (TEM) has become invaluable for the characterization of the near-surface regions of semiconductors following ion-implantation and/or transient thermal processing. A fast and reliable technique is required which produces a large thin region while preserving the original sample surface. New analytical techniques, particularly the direct imaging of dopant distributions, also require good thickness uniformity. Two methods of ion milling are commonly used, and are compared below. The older method involves milling with a single gun from each side in turn, whereas a newer method uses two guns to mill from both sides simultaneously.


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