Evaluation of moisture diffusion as a threat to polymer/inorganic nanoparticles composites properties: Polystyrene/calcium sulfate nanocomposite as a case study

2020 ◽  
pp. 096739112095686
Author(s):  
Farzaneh Besharat ◽  
Mehrdad Manteghian ◽  
Mahdi Abdollahi
Keyword(s):  
Calcium Sulfate ◽  
In Situ Polymerization ◽  
Effective Diffusion ◽  
Moisture Diffusion ◽  
Sem Analysis ◽  
Inorganic Nanoparticles ◽  
Tem Analysis ◽  
Water Diffusivity ◽  
Calculation Results

The present study aims to investigate the water diffusivity into polystyrene/ calcium sulfate (PS/CaSO4) nanocomposite samples as a threat to the intended reinforcing properties. For this purpose, CaSO4 nanoparticles were synthesized through a chemical reaction using polyethylene glycol as the stabilizing agent. The polystyrene/calcium sulfate nanocomposites were fabricated through in situ polymerization of styrene monomer and stearic acid coated CaSO4 nanoparticles. SEM analysis was applied to determine the size and shape of the produced nanoparticles. In addition, TEM analysis was applied to study the general morphology and structure of the nanocomposites in order to confirm the PS/CaSO4 nanocomposites formation. FTIR analysis was employed to study the surface functions and bonds formation in both the surface treatment and nanocomposite preparation steps. Water diffusivity into the nanocomposites was evaluated through samples water exposure followed by calculation of the effective diffusion coefficients (Deff) using the diffusion equation given by Fick’s 2nd law. The calculation results have revealed that the obtained Deff values for water diffusivity in PS/CaSO4 (1.5 wt.%) and pure PS samples were 8.73 × 10−20 and 11.1 × 10−20 m2/s, respectively.

Preparation and Characteristic of PSMA/EG Composite Materials

2010 ◽  
Vol 163-167 ◽  
pp. 1951-1954
Author(s):  
Gui Xiang Hou ◽  
Hai Ning Na ◽  
Xiao Ming Sang
Keyword(s):  
High Temperature Oxidation ◽  
In Situ Polymerization ◽  
Expanded Graphite ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Graphite Nanosheets ◽  
Composite Granules

Graphite nanosheets prepared through high-temperature oxidation via powdering the expanded graphite. After soaking the expanded graphite with styrene(S) and maleic anhydride(MA) monomers, the polymer (Poly(S-co-MA))/expanded graphite(EG) (PSMA/EG) composite granules were obtained by in situ polymerization. Light microscope，scanning electron microscope and X-ray diffraction characterization were performed. SEM analysis indicate that the expanded graphite was mostly tore to sheets with thickness of 50–80 nm and with diameter of 1μm. Optical micrographs showed that the distribution of graphite platelets is found to be nearly uniform.

scholarly journals Polystyrene Nanocomposites Reinforced with Novel Dumbbell-Shaped Phenyl-POSSs: Synthesis and Thermal Characterization

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1475 ◽  
Author(s):  
Abate ◽  
Bottino ◽  
Cicala ◽  
Chiacchio ◽  
Ognibene ◽  
...  
Keyword(s):  
In Situ Polymerization ◽  
Thermal Characterization ◽  
Sem Analysis ◽  
Morphological Properties ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Scanning Calorimetry ◽  
Filler Reinforcement ◽  
Aromatic Bridge ◽  
Very High

Two series of novel dumbbell-shaped polyhedral oligomeric silsesquioxanes (POSSs), fully functionalized with phenyl groups at the corner of the silicon cages, were used to prepare polystyrene (PS) nanocomposites through the method of in situ polymerization. The percentage of the molecular filler reinforcement was set as 5% w/w of POSS and was checked by 1H-NMR spectroscopy. The obtained nanocomposites were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Thermal and morphological properties were evaluated and compared among the nanocomposites obtained using the two different series of dumbbell-shaped POSSs and with the net PS. The thermal parameters for the prepared nanocomposites were very high when compared with those of neat PS, and they evidenced significant differences when an aliphatic or aromatic bridge was used to link the silicon cages. SEM analysis results allow us to hypothesize a justification for the different resistance to thermal degradation showed by the two series of molecular reinforcement.

scholarly journals Synthesis and Characterization of Polypyrrole (PPy) by In-situ Polymerization Technique

2020 ◽  
Vol 6 (2) ◽  
pp. 686-688
Author(s):  
Phalak Mrunalini ◽  
Rajendra Waghulade ◽  
Yogesh Toda
Keyword(s):  
In Situ Polymerization ◽  
Ammonium Persulfate ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Infra Red ◽  
Granular Morphology

This work reports synthesize of polypyrrole nano powder by chemical in-situ polymerization of pyrrole in aqueous solution and ammonium persulfate solution which acts as oxidant. It is characterized by X-ray diffraction (XRD), Fourier infra-red spectroscopy (FTIR) and scanning electron microscopy (SEM). The XRD spectrum reveals that the materials are amorphous in nature. FTIR analysis confirms that all peaks are the main characteristic of PPy. SEM analysis showed that the powder has a uniform granular morphology and the size varies from ∼500 nm to 1 μm. The micrograph of polypyrrole reveals the presence of globular particles. The formed particles are irregular in nature. The results show that the fibers are chemically formed as spherical nanostructures.

Microstructure and electrical properties in three-component (Al2O3–TiO2)/polyimide nanocomposite films

2010 ◽  
Vol 25 (12) ◽  
pp. 2384-2391 ◽  
Author(s):  
Jun-Wei Zha ◽  
Ben-Hui Fan ◽  
Zhi-Min Dang ◽  
Sheng-Tao Li ◽  
George Chen
Keyword(s):  
Glass Transition ◽  
Loss Factor ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Inorganic Nanoparticles ◽  
Nanocomposite Films ◽  
Proposed Model ◽  
Polyimide Nanocomposite

Polyimide (PI)-matrix composite films containing inorganic nanoparticles (nano-Al2O3 and nano-TiO2) have been fabricated. A proposed model is used to explain different structures of the (Al2O3–TiO2)/PI (ATP) films synthesized by employing in situ polymerization. Dependences of dielectric permittivities of the ATP films on frequency and temperature were studied. Results show the breakdown strength of the films decreases with prolonging the corona aging time. The incorporation of the nano-Al2O3 and nano-TiO2 particles significantly improves the corona resistance of the films. The corona aging also influences the infrared absorbance, the glass transition temperature (Tg), and loss factor (tanδ) of the ATP films.

Synthesis and Characterization of Polyaniline/Montmorillonite/La3+ Nanocomposites

2009 ◽  
Vol 79-82 ◽  
pp. 1547-1550
Author(s):  
Ying Bing Wu ◽  
Zun Li Mo ◽  
Hong Chen ◽  
Gui Ping Niu
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Network Structure ◽  
In Situ Polymerization ◽  
Inorganic Nanoparticles ◽  
Rare Earth Ions ◽  
Pure Pani ◽  
Gravimetric Analysis ◽  
Thermal Stability Of

A new nanocomposite consisting of polyaniline (PANI), montmorillonite (MMT) and La3+ was developed via in-situ polymerization of aniline in the presence of MMT and La3+ through emulsion polymerization, and also a novel network structure consisting of nanowires had been shaped. The morphology and the chemical structure of the product were studied by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The thermal property was exmined by mean of gravimetric analysis (TGA). The results indicated that PANI/MMT/ La3+ namocomposite has formed nanowires with diameter about 5 nm. The novel network structure consisting of nanowires has been shaped and overlapped towards certain direction. The formation of this network structure reveals that PANI molecules have been successfully inserted into the interlayer of MMT. Meanwhile, this conductivity network is believed to lead to the great improvement of the electrical conductivity for the nanocomposites. The FT-IR spectra reveal that PANI is obtained via in situ polymerization of the aniline monomer and there is a strong interaction between PANI and MMT. From XRD analysis, it can be also seen that the PANI molecules had been successfully intercalated into the galleries of the MMT. Moreover, the arrangement of PANI is more ordered in PANI/MMT/La3+ nanocomposite than that of pure PANI. From TGA curves, it is apparent that the introduction of MMT and rare-earth ions (La3+) exhibited a beneficial effect on the thermal stability of pure PANI. This markedly enhanced thermal stability of the nanocomposites can be ascribed to the MMT nanolayers acting as barriers for the degradation of PANI in the interlayer spacings and the inorganic nanoparticles trammeled the movement of the PANI molecule chains. They make the thermal decomposition of the nanocomposites at a disadvantage. As a consequence, the needed energy of the thermal decomposition increased, the thermal stability of nanocomposite increased. The paper offers a novel PANI/MMT/La3+ nanowire composites.

Laboratory and in-situ analysis of comet dust

1988 ◽  
Vol 46 ◽  
pp. 8-9
Author(s):  
D.E. Brownlee ◽  
A.L. Albee
Keyword(s):  
Electron Microscopy ◽  
Solar System ◽  
Laboratory Study ◽  
Isotopic Analysis ◽  
Building Blocks ◽  
Sem Analysis ◽  
Early Solar System ◽  
Cometary Material ◽  
Comet Dust

Comets are primitive, kilometer-sized bodies that formed in the outer regions of the solar system. Composed of ice and dust, comets are generally believed to be relic building blocks of the outer solar system that have been preserved at cryogenic temperatures since the formation of the Sun and planets. The analysis of cometary material is particularly important because the properties of cometary material provide direct information on the processes and environments that formed and influenced solid matter both in the early solar system and in the interstellar environments that preceded it.The first direct analyses of proven comet dust were made during the Soviet and European spacecraft encounters with Comet Halley in 1986. These missions carried time-of-flight mass spectrometers that measured mass spectra of individual micron and smaller particles. The Halley measurements were semi-quantitative but they showed that comet dust is a complex fine-grained mixture of silicates and organic material. A full understanding of comet dust will require detailed morphological, mineralogical, elemental and isotopic analysis at the finest possible scale. Electron microscopy and related microbeam techniques will play key roles in the analysis. The present and future of electron microscopy of comet samples involves laboratory study of micrometeorites collected in the stratosphere, in-situ SEM analysis of particles collected at a comet and laboratory study of samples collected from a comet and returned to the Earth for detailed study.

In situ TEM studies of irradiation effects for materials improvement

1991 ◽  
Vol 49 ◽  
pp. 452-453
Author(s):  
Charles W. Allen
Keyword(s):  
Nuclear Reactor ◽  
Austenitic Stainless Steels ◽  
High Energy ◽  
Point Of View ◽  
In Situ Tem ◽  
Irradiation Effects ◽  
Tem Analysis ◽  
Radiation Induced ◽  
Analytical Tools

Irradiation effects studies employing TEMs as analytical tools have been conducted for almost as many years as materials people have done TEM, motivated largely by materials needs for nuclear reactor development. Such studies have focussed on the behavior both of nuclear fuels and of materials for other reactor components which are subjected to radiation-induced degradation. Especially in the 1950s and 60s, post-irradiation TEM analysis may have been coupled to in situ (in reactor or in pile) experiments (e.g., irradiation-induced creep experiments of austenitic stainless steels). Although necessary from a technological point of view, such experiments are difficult to instrument (measure strain dynamically, e.g.) and control (temperature, e.g.) and require months or even years to perform in a nuclear reactor or in a spallation neutron source. Consequently, methods were sought for simulation of neutroninduced radiation damage of materials, the simulations employing other forms of radiation; in the case of metals and alloys, high energy electrons and high energy ions.

A technique for preparing semiconductor cross sections for both TEM and SEM analysis

1989 ◽  
Vol 47 ◽  
pp. 712-713
Author(s):  
Stanley J. Klepeis ◽  
J.P. Benedict ◽  
R.M Anderson
Keyword(s):  
Sample Preparation ◽  
Cross Section ◽  
Cross Sections ◽  
Sem Analysis ◽  
Preparation Technique ◽  
Ion Milling ◽  
Tem Analysis ◽  
Polished Cross Section ◽  
Area Of Interest ◽  
Polished Side

The ability to prepare a cross-section of a specific semiconductor structure for both SEM and TEM analysis is vital in characterizing the smaller, more complex devices that are now being designed and manufactured. In the past, a unique sample was prepared for either SEM or TEM analysis of a structure. In choosing to do SEM, valuable and unique information was lost to TEM analysis. An alternative, the SEM examination of thinned TEM samples, was frequently made difficult by topographical artifacts introduced by mechanical polishing and lengthy ion-milling. Thus, the need to produce a TEM sample from a unique,cross-sectioned SEM sample has produced this sample preparation technique.The technique is divided into an SEM and a TEM sample preparation phase. The first four steps in the SEM phase: bulk reduction, cleaning, gluing and trimming produces a reinforced sample with the area of interest in the center of the sample. This sample is then mounted on a special SEM stud. The stud is inserted into an L-shaped holder and this holder is attached to the Klepeis polisher (see figs. 1 and 2). An SEM cross-section of the sample is then prepared by mechanically polishing the sample to the area of interest using the Klepeis polisher. The polished cross-section is cleaned and the SEM stud with the attached sample, is removed from the L-shaped holder. The stud is then inserted into the ion-miller and the sample is briefly milled (less than 2 minutes) on the polished side. The sample on the stud may then be carbon coated and placed in the SEM for analysis.

Growth of Epitaxial IrSi3 Layers on Si(111)

1989 ◽  
Vol 160 ◽  
Author(s):  
T. L. Lin ◽  
C. W. Nieh
Keyword(s):  
Surface Morphology ◽  
Molecular Beam ◽  
Solid Phase ◽  
Single Mode ◽  
Growth Conditions ◽  
Tem Analysis ◽  
Mbe Growth ◽  
Good Surface ◽  
Transmission Electron

AbstractEpitaxial IrSi3 films have been grown on Si (111) by molecular beam epitaxy (MBE) at temperatures ranging from 630 to 800 °C and by solid phase epitaxy (SPE) at 500 °C. Good surface morphology was observed for IrSi3 layers grown by MBE at temperatures below 680 °C, and an increasing tendency to form islands is noted in samples grown at higher temperatures. Transmission electron microscopy (TEM) analysis reveals that the IrSi3 layers grow epitaxially on Si(111) with three epitaxial modes depending on the growth conditions. For IrSi3 layers grown by MBE at 630 °C, two epitaxial modes were observed with ~ 50% area coverage for each mode. Single mode epitaxial growth was achieved at a higher MBE growth temperature, but with island formation in the IrSi3 layer. A template technique was used with MBE to improve the IrSi3 surface morphology at higher growth temperatures. Furthermore, single-crystal IrSi3 was grown on Si(111) at 500 °C by SPE, with annealing performed in-situ in a TEM chamber.

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