scholarly journals Synthesis and Properties of Polyacrylamide-Bismuth Halogenated Hybrids

1996 ◽  
Vol 19 (2) ◽  
pp. 99-104 ◽  
Author(s):  
G. Campet ◽  
L. Rabardel ◽  
J. Portier ◽  
H. S. Dweik ◽  
M. A. Subramanian
Keyword(s):  
Amorphous Material ◽  
Polymeric Matrix ◽  
Carbonyl Groups ◽  
Small Particles ◽  
Polymeric Salt ◽  
Uv Visible ◽  
Bismuth Chloride

When solid polyacrylamide (PAam) is added to a solution of bismuth chloride, a polymeric salt of composition (CH2-CH-CONH2)n BiCl3(n > 10) is obtained. This amorphous material is transparent in the visible. In this hybrid, bismuth seems to be coordinated both to amine and carbonyl groups. When the PAam-BiCI3hybrid is swollen with a KI solution, the corresponding iodide salt is formed with probably small particles of Bil3precipitated into the polymeric matrix. Chemical, thermal, and optical (in the UV, visible, and infrared regions) properties of the salt and of the composite are studied.

scholarly journals A Comparative Study of Different Synthetic Methods of Copper Metal-Organic Frameworks (Cu-MOF)

2021 ◽  
Vol 33 (10) ◽  
pp. 2360-2364
Author(s):  
P.M. Thabede ◽  
N.D. Shooto
Keyword(s):  
Metal Organic Framework ◽  
Amorphous Material ◽  
Synthetic Methods ◽  
Microwave Method ◽  
Sem Images ◽  
Optical Absorption Band ◽  
Vis Spectroscopy ◽  
Metal Organic ◽  
Diffraction Peaks ◽  
Uv Visible

The metal-organic framework of copper (Cu-MOF) was prepared using the reflux method and microwave method. The results of the two techniques were compared with each other to determine the best method to prepare Cu-MOF. Preparation of Cu-MOF using different techniques has shown that it influences the morphology of the MOF. The results showed that there was a correlation between the two methods. The obtained products were characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA) and ultraviolet-visible (UV-Vis) spectroscopy. The SEM images showed that the microwave method synthesized particles were cubic while the reflux method produced amorphous material. The XRD spectra showed intense diffraction peaks at 2θ values of 17.61º, 20.47º, 25.34º, 29.59º, 43.01º and their miller indices were (511), (442), (731), (751) and (662), respectively. FTIR results revealed that the materials had functional groups such as (C=O, C-O, O-C=O and Cu-O), UV-visible results showed optical absorption band of Cu-MOF was at 274.18 nm for the microwav and 274.41 nm for the reflux methods. This band could be allocated to the charged transfer from the oxygen in carboxylate to Cu2+ ions.

SYNTHESIS AND CHARACTERIZATION OF LUMINESCENT POLYHYDROXYPYRIDINE LINKED WITH AROMATIC OXADIAZOLE

2004 ◽  
Vol 13 (03n04) ◽  
pp. 613-619 ◽  
Author(s):  
YOUNG-SHIN KIM ◽  
WON HO PARK ◽  
TAEK SEUNG LEE
Keyword(s):  
Thermal Decomposition ◽  
Amorphous Material ◽  
Decomposition Temperature ◽  
Synthesis And Characterization ◽  
Polycondensation Reaction ◽  
Thermal Decomposition Temperature ◽  
Blue Fluorescence ◽  
Uv Visible ◽  
Film State

A new copoly(hydroxypyridine-oxadiazole) linked with 2,5-dialkoxybenzene group was prepared via simple polycondensation reaction. The polymer 4 is basically an amorphous material with thermal decomposition temperature greater than 250°C. Introduction of ethylhexyloxy groups into the rigid backbone resulted in better solubility in common organic solvents such as THF, chloroform, and DMF. UV-visible and fluorescence spectrometers were employed to investigate the optical properties both in solution and in the film state showing that the material has blue fluorescence.

Synthesis and Photocatalytic Activity of Ag Doped TiO2 Nanofibers

2018 ◽  
Vol 913 ◽  
pp. 1027-1032 ◽  
Author(s):  
Hong Ying Dong ◽  
Qing Hong Sun ◽  
Ting Ting Zhang ◽  
Qi Ren ◽  
Wen Ma
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Degradation Rate ◽  
Sol Gel ◽  
Experimental Results ◽  
Small Particles ◽  
Gel Method ◽  
Sol Gel Method ◽  
Uv Visible ◽  
20 Nm

Ag/TiO2nanofibers were obtained by sol-gel method combined with uniaxial electrospinning. The effects of different sintering temperatures (400°C, 500°C, 600°C) and different concentrations of silver (0 wt%, 0.5 wt%, 1.0 wt%, 1.5 wt%) on photocatalytic activity of TiO2were investigated. The morphology and interface interaction of the Ag/TiO2composites were investigated by SEM, TEM, XRD and UV-visible spectrophotometer. The experimental results showed that the diameter of the fiber sintered at 400°C is about 120 nm and the fiber is composed of 10-20 nm small particles. The degradation rate of methylene blue was 71% for the Ag/TiO2composites fiber with 1.0wt% silver and sintered at 400°C.

Atomic structure analysis of small particles supported on amorphous material

1987 ◽  
Vol 45 ◽  
pp. 104-105
Author(s):  
M.L. Sattler ◽  
M.A. O'Keefe
Keyword(s):  
Present Method ◽  
Amorphous Material ◽  
Average Particle Size ◽  
Image Interpretation ◽  
Average Particle ◽  
Hrem Image ◽  
Small Particles ◽  
Simulated Images ◽  
Background Contrast ◽  
Previous Image

The direct observation of atomic features in small crystalline particles supported by a thicker substrate is useful when characterizing materials such as electrocatalysts. However, particle definition becomes difficult to establish for catalyst crystallites less than 5nm in diameter on a support 5 to 10 times thicker, since the background contrast obscures the HREM image of the particle. Previous image calculations of 2.4nm sized particles on 10nm amorphous support have demonstrated further the problems associated with image interpretation of these small particles. The present method incorporates the matching of simulated images at varying thicknesses with computer enhanced images of small particles on amorphous supports in order to characterize atomic details at the surfaces of these particles.Catalyst material consisting of crystalline Ti02 particles on an amorphous Si02 support was developed so that the average particle size measured 7.0nm.

Proteus penneri Assisted Synthesis of Metal Nanoparticles: Biofunctional Evaluation and Characterization

2018 ◽  
Vol 11 (4) ◽  
pp. 4169-4176
Author(s):  
Satish S ◽  
Spoorthy H. P. ◽  
Vasanth Patil H B ◽  
Rekha N D
Keyword(s):  
Metal Nanoparticles ◽  
Antibacterial Property ◽  
Metal Nanoparticle ◽  
Amino Acid Residues ◽  
Carbonyl Groups ◽  
Visible Spectroscopy ◽  
Gram Negative ◽  
Zinc Nanoparticles ◽  
Uv Visible ◽  
Proteus Penneri

The metal nanoparticles synthesized by green synthesis can be used as an alternative strategy to overcome antimicrobial resistance. In this study, metal nanoparticles were synthesized using Proteus penneri, a Gram-negative rod-shaped bacteria that facilitated the reduction of metals into their respective nanoparticles. Biosynthesized particles were characterized by DLS, SEM, UV-visible spectroscopy. It was selected for the study and was found to have the ability to form silver, gold, chromium, copper, nickel and zinc nanoparticles as observed by change in color of the reaction. The spectral analysis confirmed the presence of carbonyl groups from the amino acid residues wherein proteins have the stronger capability to bind the metal that probably aid in the formation of metal nanoparticles. Antibacterial property reveals that silver, gold and chromium based metal nanoparticle are best suitable candidates to overcome antibiotic resistance. Zn and Au showed significant anti-inflammatory property by inhibiting PLA2, further they could inhibit angiogenesis there by exhibiting anti cancerous property

Crystallization of Glassy Powder from Aluminum-Rare Earth- Transition Metal Alloys

2002 ◽  
Vol 754 ◽  
Author(s):  
A.L. Vasiliev ◽  
M. Aindow ◽  
M.J. Blackburn ◽  
T.J. Watson
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Rare Earth ◽  
Transition Metal ◽  
Amorphous Matrix ◽  
Amorphous Material ◽  
Metal Alloys ◽  
Small Particles ◽  
Transition Metal Alloys ◽  
Nanocrystalline Particles

ABSTRACTThe microstructures exhibited by gas atomized powders of two alloys, Al-6Gd-6Ni-1Fe and Al-5Y-10Ni (at. %), have been analyzed using electron microscopy. It was found that the microstructure depends critically on the particle size obtained during atomization. Small particles (<1μm) tend to be completely amorphous. Larger particles (1–10μm) can also be amorphous, but often contain a mixture of amorphous material and crystalline Al. Three distinct morphologies are observed: nanocrystalline particles, fractal and dendritic growths embedded in an amorphous matrix. The yet larger particles (>30μm) are often fully crystalline, consisting of fine interspersed Al and intermetallic grains.

Stereo Electron Microscopy Applied to High Resolution Freeze-Etch Replicas

1970 ◽  
Vol 28 ◽  
pp. 306-307
Author(s):  
L. Andrew Staehelin
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
High Resolution ◽  
Smooth Surfaces ◽  
Small Particles ◽  
Membrane Surfaces ◽  
Wide Acceptance ◽  
New Information ◽  
Number Of Particles ◽  
Small Holes

Freeze-etched membranes usually appear as relatively smooth surfaces covered with numerous small particles and a few small holes (Fig. 1). In 1966 Branton (1“) suggested that these surfaces represent split inner mem¬brane faces and not true external membrane surfaces. His theory has now gained wide acceptance partly due to new information obtained from double replicas of freeze-cleaved specimens (2,3) and from freeze-etch experi¬ments with surface labeled membranes (4). While theses studies have fur¬ther substantiated the basic idea of membrane splitting and have shown clearly which membrane faces are complementary to each other, they have left the question open, why the replicated membrane faces usually exhibit con¬siderably fewer holes than particles. According to Branton's theory the number of holes should on the average equal the number of particles. The absence of these holes can be explained in either of two ways: a) it is possible that no holes are formed during the cleaving process e.g. due to plastic deformation (5); b) holes may arise during the cleaving process but remain undetected because of inadequate replication and microscope techniques.

Glass Knife Geometry as Seen by the SEM

1971 ◽  
Vol 29 ◽  
pp. 454-455
Author(s):  
J. Temple Black
Keyword(s):  
Low Cost ◽  
Amorphous Material ◽  
Stress Concentrations ◽  
Basic Tool ◽  
Tool Materials ◽  
Optical Inspection ◽  
Surface Flaws ◽  
Slip Planes ◽  
Glass Knife ◽  
Diamond Knife

In ultramicrotomy, the two basic tool materials are glass and diamond. Glass because of its low cost and ease of manufacture of the knife itself is still widely used despite the superiority of diamond knives in many applications. Both kinds of knives produce plastic deformation in the microtomed section due to the nature of the cutting process and microscopic chips in the edge of the knife. Because glass has no well defined slip planes in its structure (it's an amorphous material), it is very strong and essentially never fails in compression. However, surface flaws produce stress concentrations which reduce the strength of glass to 10,000 to 20,000 psi from its theoretical or flaw free values of 1 to 2 million psi. While the microchips in the edge of the glass or diamond knife are generally too small to be observed in the SEM, the second common type of defect can be identified. This is the striations (also termed the check marks or feathers) which are always present over the entire edge of a glass knife regardless of whether or not they are visable under optical inspection. These steps in the cutting edge can be observed in the SEM by proper preparation of carefully broken knives and orientation of the knife, with respect to the scanning beam.

Dynamic Scanning Electron Microscopy of Small Particles

1975 ◽  
Vol 33 ◽  
pp. 280-281
Author(s):  
W. Krakow ◽  
W. C. Nixon
Keyword(s):  
Electron Microscopy ◽  
Low Noise ◽  
Time Sequence ◽  
Field Of View ◽  
Video Tape ◽  
Small Particles ◽  
Polystyrene Spheres ◽  
Field Distributions ◽  
Dynamic Scanning ◽  
Scanning Electron

The scanning electron microscope (SEM) can be run at television scanning rates and used with a video tape recorder to observe dynamic specimen changes. With a conventional tungsten source, a low noise TV image is obtained with a field of view sufficient to cover the area of the specimen to be recorded. Contrast and resolution considerations have been elucidated and many changing specimens have been studied at TV rates.To extend the work on measuring the magnitude of charge and field distributions of small particles in the SEM, we have investigated their motion and electrostatic interaction at TV rates. Fig. 1 shows a time sequence of polystyrene spheres on a conducting grating surface inclined to the microscope axis. In (la) there are four particles present in the field of view, while in (lb) a fifth particle has moved into view.

The Shadow Widths of Very Small Particles are Formed Independently of the Metal Cap Build Up on the Particle

1981 ◽  
Vol 39 ◽  
pp. 568-569
Author(s):  
George C. Ruben
Keyword(s):  
Gold Particle ◽  
Film Surface ◽  
Small Particles ◽  
Geometric Process ◽  
Metal Free ◽  
Shadow Area

The formation of shadows behind small particles has been thought to be a geometric process (GP) where the metal cap build up on the particle creates a shadow width the same size as or larger than the particle. This GP cannot explain why gold particle shadow widths are generally larger than the gold particle and may have no appreciable metal cap build up (fig. 1). Ruben and Telford have suggested that particle shadow widths are formed by the width dependent deflection of shadow metal (SM) lateral to and infront of the particle. The trajectory of the deflected SM is determined by the incoming shadow angle (45°). Since there can be up to 1.4 times (at 45°) more SM directly striking the particle than the film surface, a ridge of metal nuclei lateral to and infront of the particle can be formed. This ridge in turn can prevent some SM from directly landing in the metal free shadow area. However, the SM that does land in the shadow area (not blocked by the particle or its ridge) does not stick and apparently surface migrates into the SM film behind the particle.

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