scholarly journals Novel Color Change Film as a Time–Temperature Indicator Using Polydiacetylene/Silver Nanoparticles Embedded in Carboxymethyl Cellulose

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2306
Author(s):  
Aphisit Saenjaiban ◽  
Teeranuch Singtisan ◽  
Panuwat Suppakul ◽  
Kittisak Jantanasakulwong ◽  
Winita Punyodom ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Electron Micrographs ◽  
Carboxymethyl Cellulose ◽  
Fruits And Vegetables ◽  
Color Change ◽  
Color Difference ◽  
Scanning Electron Micrographs ◽  
Transmission Electron ◽  
Kinetics Of ◽  
Total Color Difference

Time–temperature indicators (TTIs) can be important tools in product applications to monitor food quality losses, especially for fruits and vegetables. In this context, the effects of silver nanoparticles (AgNPs) and glycerol on the color change of polydiacetylene/AgNPs (PDA/AgNPs) embedded in carboxymethyl cellulose (CMC) film as time–temperature indicators (TTIs) were investigated. A CMC film prepared with 30 mg/L AgNPs and a 1:3 (v/v) PDA:AgNP ratio exhibited a faster color change than under other conditions. At 35 °C, the films with PDA/AgNPs changed color from purplish-blue to purple and purple to reddish-purple over time due to the higher thermal conductivity of AgNPs and larger PDA surface area exposed to specific temperatures. The total color difference (TCD) of PDA/AgNP-embedded CMC film directly changed with regard to time and temperature. However, adding glycerol to the system resulted in a symmetrical chemical structure, a factor that delayed the color change. Scanning electron micrographs showed AgNPs embedded in the CMC films. Transmission electron micrographs indicated a core-shell structure of PDA/AgNP vesicles in the CMC matrix. PDA/AgNP vesicles were confirmed by second derivative Fourier transform infrared spectroscopy, with a new peak at 1390–1150 cm−1. The kinetics of TTIs from PDA/AgNP-embedded CMC films yielded an activation energy of 58.70 kJ/mol.

scholarly journals The Synergistic Effect of Biosynthesized Silver Nanoparticles and Phage ZCSE2 as a Novel Approach to Combat Multidrug-Resistant Salmonella enterica

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 678
Author(s):  
Abdallah S. Abdelsattar ◽  
Rana Nofal ◽  
Salsabil Makky ◽  
Anan Safwat ◽  
Amera Taha ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Color Change ◽  
Antibacterial Properties ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Mortality And Morbidity ◽  
Novel Approach ◽  
Transmission Electron

The emergence and evolution of antibiotic-resistant bacteria is considered a public health concern. Salmonella is one of the most common pathogens that cause high mortality and morbidity rates in humans, animals, and poultry annually. In this work, we developed a combination of silver nanoparticles (AgNPs) with bacteriophage (phage) as an antimicrobial agent to control microbial growth. The synthesized AgNPs with propolis were characterized by testing their color change from transparent to deep brown by transmission electron microscopy (TEM) and Fourier-Transform Infrared Spectroscopy (FTIR). The phage ZCSE2 was found to be stable when combined with AgNPs. Both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for AgNPs, phage, and their combination. The results indicated that MIC and MBC values were equal to 23 µg/mL against Salmonella bacteria at a concentration of 107 CFU/mL. The combination of 0.4× MIC from AgNPs and phage with Multiplicity of Infection (MOI) 0.1 showed an inhibitory effect. This combination of AgNPs and phage offers a prospect of nanoparticles with significantly enhanced antibacterial properties and therapeutic performance.

The ultrastructure of the epidermis of the redia and cercaria of Parorchis acanthus, Nicoll. A study by scanning and transmission electron-microscopy

Parasitology ◽  
1971 ◽  
Vol 62 (3) ◽  
pp. 479-488 ◽  
Author(s):  
Gwendolen Rees
Keyword(s):  
Electron Micrographs ◽  
Technical Assistance ◽  
Ventral Surface ◽  
The Body ◽  
Muscle Fibres ◽  
Scanning Electron Micrographs ◽  
Large Area ◽  
Transmission Electron ◽  
Parorchis Acanthus ◽  
Scanning Electron

Scanning electron-micrographs have shown the covering of microvilli on the surface of the redia of Parorchis acanthus. In the contracted state the elongated microvilli with bulbous extremities seen in the surface grooves may be the result of compression. The surface of the epidermis of the cercaria is smooth on a large area of the ventral surface and lattice-like with microvilli, laterally, anteriorly, dorsally and on the tail. The spines on the body can be withdrawn into sheaths by the contraction of muscle fibres inserted into the basement lamina below each spine.I would like to express my sincere gratitude to Dr I. ap Gwynn of this department for preparing the scanning electron-micrographs and the School of Engineering Science, University of North Wales, Bangor for the use of their stereoscan. I should also like to thank Mr M. C. Bibby for technical assistance and Professor E. G. Gray and Dr W. Sinclair for assistance with the transmission electron-micrographs.

Transmission electron microscopic study of antennal sensilla of the female black fly, Simulium arcticum (IIL-3; IIS-10.11) (Diptera: Simuliidae)

1990 ◽  
Vol 68 (7) ◽  
pp. 1443-1453 ◽  
Author(s):  
J. F. Sutcliffe ◽  
E. G. Kokko ◽  
J. L. Shipp
Keyword(s):  
Electron Micrographs ◽  
Host Location ◽  
Scanning Electron Micrographs ◽  
Antennal Sensilla ◽  
Electron Microscopic ◽  
Olfactory Sensilla ◽  
Transmission Electron Microscopic Study ◽  
Sensilla Trichodea ◽  
Transmission Electron ◽  
Transmission Electron Microscopic

The innervation and internal ultrastructure of the antennal flagellar sensilla of female Simulium arcticum (cytotypes IIL-3 and IIS-10.11) are described from transmission electron micrographs. Two types of contact chemosensilla and at least four types of olfactory sensilla (sensilla trichodea, two or more types of sensilla basiconica, grooved pegs) were found. These correspond to sensillar types previously described from scanning electron micrographs of the antennae of these species. In addition, possible thermo- and hygro-receptive sensilla coeloconica are described from the antennal tip. The sensory complement of the simuliid antenna is compared with those of certain other dipterans, and possible roles of these sensilla in host location and other behaviours are discussed.

Metallography of Aluminum Alloys: Atlas of Microstructures

2019 ◽  
Author(s):  
S.V.S. Narayana Murty ◽  
Sushant K. Manwatkar ◽  
P. Ramesh Narayanan
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Microstructural Evolution ◽  
Electron Micrographs ◽  
Thermomechanical Processing ◽  
Alloy System ◽  
Scanning Electron Micrographs ◽  
Cast Aluminum Alloys ◽  
Transmission Electron ◽  
Evolution Of Microstructure

Microstructure plays an important role in obtaining the desired properties in metallic materials in general and aluminum alloys in particular. Mechanical properties of aluminum alloys can be significantly altered by changing the microstructure. No other alloy system can boast of as many temper conditions as aluminum alloys. With the progress in the understanding of microstructure–mechanical property relationships in these materials, “tailor made” alloys to meet specific demands are being industrially developed. The broad spectrum of aluminum alloys in wide range of temper conditions offer materials with widely varying mechanical properties for structural designers. In order to select aluminum alloys with the desired properties for the intended application, it is essential to understand the role of microstructure under actual service conditions. It is in this context “Metallography of aluminum alloys” becomes very important. This chapter provides an insight in to the microstructural evolution of aluminum alloys from the as-cast condition to the final product. Typical examples of microstructural evolution in different aluminum alloys under various thermomechanical conditions are presented here. An atlas of microstructures of commercial and experimental wrought and cast aluminum alloys is presented in an appendix to this book. This appendix includes optical photomicrographs of both cast and wrought alloys and scanning electron micrographs of polished surfaces as well as fracture surfaces of various aluminum alloys as well as transmission electron micrographs as separate annexure. Readers are encouraged to go through the optical microstructures and fractographs along with this chapter for better understanding of the evolution of microstructure as a function of alloying additions, thermomechanical processing conditions, and fracture behavior under tension.

The Nanofabrication of Quantum Wires for the Next Generation of Thermoelectrics

1998 ◽  
Vol 545 ◽  
Author(s):  
D. L. Demske ◽  
J. L. Price ◽  
N. A. Guardala ◽  
N. Lindsey ◽  
J. H. Barkyoumb ◽  
...  
Keyword(s):  
Electron Micrographs ◽  
Quantum Wires ◽  
Incident Beam ◽  
Scanning Electron Micrographs ◽  
Carbon Ions ◽  
Atomic Force ◽  
Transmission Electron ◽  
Ion Accelerator ◽  
Current Voltage ◽  
Potentiostatic Electrodeposition

AbstractThe fabrication of a thermoelectric nanocomposite material consisting of nanometer scale bismuth (Bi) wires embedded in a porous mica template host is discussed in detail. In fabricating the mica templates, a positive ion accelerator is employed to irradiate 10 μm thick mica sheets with collimated beams of 15 MeV carbon ions at fluence levels of 1.5 × 1013 ions/cm2. The normally incident beam generates latent nuclear damage tracks in the direction oriented perpendicularly to the mica basal plane. Atomic Force Microscope (AFM) pictures of etched tracks verify that we have fabricated porous templates containing arrays of channels with densities up to 1013/cm2 and diameters as small as 5 nanometers, thus providing pores having an aspect ratio of about 2000:1. Scanning electron micrographs of 50 nm diameter tracks show that these are parallel channels with smooth, non-tapered walls. In addition, to fabricate the wires we have developed a solution-electrodeposition process employing a PC processor-driven potentiostatic/galvanostatic system. Currently, we are electrochemically embedding 10 μm long Bi wires through the nanochannel templates. The potentiostatic electrodeposition behavior of these wires is described. Current-voltage waveforms confirm that the wires are electrically uninterrupted through the mica template. Transmission electron micrographs (TEM) show these wires are single crystals, of well-defined orientation with diameters down to 50 Å. We observe bundles of 80 Å wires with a packing density of about 109/cm2. Energy Dispersive X-ray Spectroscopy (EDS) has corroborated the presence of Bi in the nanochannels. The observation of the bismuth crystal orientation in the porous mica template is examined.

scholarly journals Biosynthesis and Kinetics of Silver Nanoparticles Formation by Reduction using Banana Kepok (Musa balbisiana) Peel Extract

2018 ◽  
Vol 17 (2) ◽  
pp. 77 ◽  
Author(s):  
Wara Dyah Pita Rengga ◽  
Dhimas Setiawan ◽  
Khosiatun Khosiatun
Keyword(s):  
Silver Nanoparticles ◽  
Formation Rate ◽  
Spherical Particles ◽  
Banana Peel ◽  
Musa Balbisiana ◽  
Transmission Electron ◽  
The Face ◽  
Face Centered ◽  
Kinetics Of ◽  
Peel Extract

Biosynthesis and silver nanoparticles formation during the reduction of AgNO3were carried out by using an aqueous peel extract of banana kepok (Musa balbisiana) asa stabilizing agent. The formation of the stable silver nanoparticles with differentconcentration of AgNO3 has resulted in mostly spherical particles. The Ultraviolet-Visiblespectrophotometer, Transmission Electron Microscopy, X-Ray Diffractometer were usedto characterize these biosynthesized silver nanoparticles. The spherical shapednanoparticles were uniformly distributed with the range diameter of 5 to 50 nm and theparticles were naturally crystallized with the crystal structure of the face-centered cubicgeometry. Additionally, the kinetics of the formation process of silver nanoparticles wasobserved by the UV-Vis spectrophotometer. Based on the kinetic functions, the reductionprocess of banana peel extract had a constant formation rate of the autocatalytic processat 4.35 x 10-4/s.

scholarly journals Vitis vinifera Assisted Silver Nanoparticles with Antibacterial and Antiproliferative Activity against Ehrlich Ascites Carcinoma Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
A. K. M. Asaduzzaman ◽  
Byung-Soo Chun ◽  
Syed Rashel Kabir
Keyword(s):  
Silver Nanoparticles ◽  
Vitis Vinifera ◽  
Antiproliferative Activity ◽  
Color Change ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Transmission Electron ◽  
Ehrlich Ascites ◽  
Biosynthesized Agnps ◽  
Mild Toxicity

Vitis vinifera extract assisted silver nanoparticles (AgNPs) were biosynthesized that was confirmed primarily by color change and a sharp plasmon absorption band was found at 449 nm. Biosynthesized AgNPs shape was spherical and the particle size of 17 nm in average was confirmed by transmission electron microscopy (TEM) images. Functional groups of AgNPs were identified by Fourier transform infrared spectroscopy (FTIR). Streptococcus aureus was the most sensitive bacteria towards the assisted V. vinifera AgNPs as their growth was 90% inhibited at 100 μg/mL concentration. That was also confirmed by the zone of inhibition study. Up to 96 h, no biofilm was observed for K. pneumoniae at 40 μg/mL of AgNPs. Although AgNPs showed a mild toxicity against brine shrimp nauplii, it showed a remarkable level of antiproliferative activity against Ehrlich ascites carcinoma (EAC) cells.

scholarly journals Preparation, Characterization, and Application of Magnetic Fe-SBA-15 Mesoporous Silica Molecular Sieves

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Huayu Huang ◽  
Yongsheng Ji ◽  
Zhenfeng Qiao ◽  
Chuande Zhao ◽  
Jianguo He ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Magnetic Materials ◽  
Magnetic Separation ◽  
Electron Micrographs ◽  
Molecular Sieves ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Metal Form ◽  
Scanning Electron

Magnetic Fe-SBA-15 mesoporous silica molecular sieves were prepared, characterized, and used for magnetic separation. Wet impregnation, drying, and calcination steps led to iron inclusion within the mesopores. Iron oxide was reduced to the metal form with hydrogen, and the magnetic Fe-SBA-15 was obtained. Fourier-transform infrared spectroscopy confirmed the preparation process from the oxide to metal forms. The structure of magnetic materials was confirmed by Mössbauer spectra. Powder X-ray diffraction data indicated that the structure of Fe-SBA-15 retained the host SBA-15 structure. Brunauer-Emmett-Teller analysis revealed a decrease in surface area and pore size, indicating Fe-SBA-15 coating on the inner surfaces. Scanning electron micrographs confirmed the decrease in size for modified SBA-15 particles. From scanning electron micrographs, it was found that the size of the modified SBA-15 particles decreased. Transmission electron micrographs also confirmed that modified SBA-15 retained the structure of the parent SBA-15 silica. Fe-SBA-15 exhibited strong magnetic properties, with a magnetization value of 8.8 emu g-1. The iron content in Fe-SBA-15 was determined by atom adsorption spectroscopy. Fe-SBA-15 was successfully used for the magnetic separation of three aromatic compounds in water. Our results suggest wide applicability of Fe-SBA-15 magnetic materials for the rapid and efficient separation of various compounds.

scholarly journals Star-Shaped Poly(2-ethyl-2-oxazoline) and Poly(2-isopropyl-2-oxazoline) with Central Thiacalix[4]Arene Fragments: Reduction and Stabilization of Silver Nanoparticles

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2006 ◽  
Author(s):  
Alexey Lezov ◽  
Alexander Gubarev ◽  
Maria Mikhailova ◽  
Alexandra Lezova ◽  
Nina Mikusheva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Resonance Peak ◽  
Time Dependent ◽  
Colloidal Solutions ◽  
X Ray Diffraction ◽  
Plasmon Resonance Peak ◽  
X Ray ◽  
Transmission Electron ◽  
Kinetics Of

The interaction of silver nitrate with star-shaped poly(2-ethyl-2-oxazoline) and poly(2-isopropyl-2-oxazoline) containing central thiacalix[4]arene cores, which proceeds under visible light in aqueous solutions at ambient temperature, was studied. It was found that this process led to the formation of stable colloidal solutions of silver nanoparticles. The kinetics of the formation of the nanoparticles was investigated by the observation of a time-dependent increase in the intensity of the plasmon resonance peak that is related to the nanoparticles and appears in the range of 400 to 700 nm. According to the data of electron and X-ray spectroscopy, scanning and transmission electron microscopy, X-ray diffraction analysis, and dynamic light scattering, the radius of the obtained silver nanoparticles is equal to 30 nm. In addition, the flow birefringence experiments showed that solutions of nanoparticles have high optical shear coefficients.

Sign in / Sign up

Export Citation Format

Share Document