Effect of reaction parameters on the particle sizes of crosslinked spherical phenolic beads by suspension polymerization of phenol and formaldehyde

2006 ◽  
Vol 100 (3) ◽  
pp. 2323-2330 ◽  
Author(s):  
Arjun Singh ◽  
Darshan Lal
Keyword(s):  
Suspension Polymerization ◽  
Particle Sizes ◽  
Reaction Parameters

Effects of triethoxy and triphenylvinylsilanes on the porous structure of cross-linked poly(methyl methacrylate) beads

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Javaherian Naghash Hamid ◽  
Dehghan Fariba ◽  
Massah Ahmad Reza
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Suspension Polymerization ◽  
Particle Sizes ◽  
Swelling Ratio ◽  
Measurement Results ◽  
Swelling Studies ◽  
Volume Swelling ◽  
First Time ◽  
Scanning Electron

AbstractNovel microprous beads with the particle size of about 0.6-1.1 mm were prepared for the first time, from methylmethacrylate (MMA), ethyleneglycol dimethacrylate (EGDM), triethoxyvinylsilane (TEVS) and triphenylvinylsilane (TPVS) by suspension polymerization technique. In this study toluene was used as solvent. The swelling measurement results indicate that increasing silicone concentration increases the amount of pores and porosity percent, the weight swelling ratio, and particle sizes, but it has been observed that the apparent density decreases in the case of TEVS, and not in the case of TPVS. Also it has been demonstrated that the volume swelling ratio is independent of TEVS and increases by increasing TPVS concentration. The resulting copolymer beads were characterized by using swelling studies and Fourier transform infrared spectroscopy (FTIR). The morphology of copolymer beads were also investigated by scanning electron microscopy (SEM) and optical microscopy (OM).

Aluminum nanoparticle preparation via catalytic decomposition of alane adducts – influence of reaction parameters on nanoparticle size, morphology and reactivity

2020 ◽  
Vol 49 (28) ◽  
pp. 9820-9834
Author(s):  
Thomas Klein ◽  
Guido Kickelbick
Keyword(s):  
Small Particle ◽  
Reaction Times ◽  
Catalytic Decomposition ◽  
Nanoparticle Size ◽  
Particle Sizes ◽  
Reaction Parameters ◽  
Mild Conditions ◽  
Al Nanoparticles ◽  
Nanoparticle Preparation ◽  
Size And Morphology

Al nanoparticles have been prepared via catalytic decomposition. The influence of various reaction parameters on their size and morphology was studied. The reaction was optimized towards short reaction times, small particle sizes, and mild conditions.

Preparation and Characterization of Thermally Expandable Microspheres

2016 ◽  
Vol 852 ◽  
pp. 596-600 ◽  
Author(s):  
Shu Ying Chen ◽  
Zhi Cheng Sun ◽  
Lu Hai Li
Keyword(s):  
Suspension Polymerization ◽  
Volume Ratio ◽  
Particle Sizes ◽  
Phase Volume ◽  
Structure And Property ◽  
Structure Characteristics ◽  
Phase Volume Ratio ◽  
Foaming Temperature ◽  
Crosslinking Agents

The thermally expandable microspheres were prepared through suspension polymerization with acrylonitrile (AN), methyl methacrylate (MMA) and methyl acrylate (MA) as monomers. The experimental results showed that it was possible to apply suspension polymerization to prepare the high foaming ratio and equally distributed microcapsules when water and oil phase volume ratio of 3:1, AN-MMA-MA in the proportion of 70%/20%/10% (m/m/m), and 1,4-butanediol dimethacrylate (BDDMA) as the crosslinking agents. Furthermore, the structure and property of shell and nuclear were characterized by Infrared Spectra (IR), Scanning Electron Microscopy (SEM) and Thermal analysis (TG, DTG). The structure characteristics and effective factors of copolymer coated core materials, morphologies, particle sizes, foaming temperature and ratio of microcapsules were investigated in this paper.

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

TEM study on fine carbide precipitates and dislocation cell structure

1990 ◽  
Vol 48 (4) ◽  
pp. 904-905
Author(s):  
Mengzhe Chen ◽  
Siqin Wang ◽  
Jun Ke
Keyword(s):  
Carbide Particle ◽  
Cell Structure ◽  
Ferrite Matrix ◽  
Dislocation Cell ◽  
Isothermal Treatment ◽  
Particle Sizes ◽  
Dislocation Cell Structure ◽  
Thin Foils ◽  
Hsla Steels ◽  
Fine Carbide

A series of investigations have been conducted into the nature and origin of the dislocation cell structure. R.J.Klassen calculated that the dislocation cell limiting size in pure ferrite matrix is about 0.4 μm. M.N.Bassion estimated the size of dislocation cell in deformed ferrite of HSLA steels to be of the same order.In this paper, TEM observation has been concentrated on the interaction of fine carbide precipitates with dislocation cell structure in deformed Fe-C-V (0.05%C, 0.13% and 0.57%V) and Fe-C-Nb (0.07 %C and 0.04%Nb) alloys and compared with that in Fe-C (0.05%). Specimens were austenitized at 1500 “C/20 min and followed by isothermal treatment at 750 °C and 800 “C for 20, 40 and 120 minutes . The carbide particle sizes in these steels are from 9 to 86nm measured from carbon extraction replicas. Specimens for TEM were cut from differently deformed areas of tensile specimens deformed at room temperture. The thin foils were jet electropolished at -20 C in a solution of 10% perchloric acid and 90% ethanol. The TEM observation was carried out in JEM 100CX , EM420 at 100kv and JEM 2000FX at 200kv.

A High Resolution Study of Alumina Supported Iridium Catalysts

1980 ◽  
Vol 38 ◽  
pp. 202-203
Author(s):  
C. Stoeckert ◽  
B. Etherton ◽  
M. Beer ◽  
J. Gryder
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Metal Particles ◽  
Optical Transfer Function ◽  
Particle Sizes ◽  
Iridium Catalysts ◽  
Transmission Electron ◽  
Optical Transfer ◽  
Conventional Transmission Electron Microscope ◽  
Resolution Study

The interpretation of the activity of catalysts requires information about the sizes of the metal particles, since this has implications for the number of surface atoms available for reaction. To determine the particle dimensions we used a high resolution STEM1. Such an instrument with its simple optical transfer function is far more suitable than a conventional transmission electron microscope for the establishment of particle sizes. We report here our study on the size and number distribution of Ir particles supported on Al2O3 and also examine simple geometric models for the shape of Ir particles.

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