scholarly journals Thiol-Functional Polymer Nanoparticles via Aerosol Photopolymerization

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4363
Author(s):  
Narmin Suvarli ◽  
Iris Perner-Nochta ◽  
Jürgen Hubbuch ◽  
Michael Wörner
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Functional Groups ◽  
Residence Time ◽  
Polymer Nanoparticles ◽  
Vinyl Ethers ◽  
Sh Groups ◽  
Scanning Electron ◽  
Half Minute ◽  
Individual Polymer

Spherical, individual polymer nanoparticles with functional –SH groups were synthesized via aerosol photopolymerization (APP) employing radically initiated thiol-ene chemistry. A series of various thiol and alkene monomer combinations were investigated based on di-, tri-, and tetrafunctional thiols with difunctional allyl and vinyl ethers, and di- and trifunctional acrylates. Only thiol and alkene monomer combinations able to build cross-linked poly(thio-ether) networks were compatible with APP, which requires fast polymerization of the generated droplet aerosol during the photoreactor passage within a residence time of half-minute. Higher monomer functionalities and equal overall stoichiometry of functional groups resulted in the best nanoparticles being spherical and individual, proven by scanning electron microscopy (SEM). The presence of reactive—SH groups in the synthesized nanoparticles as a basis for post-polymerization modifications was verified by Ellman’s test.

scholarly journals Biochar produced from poultry litter waste

2021 ◽  
Vol 10 (11) ◽  
pp. e351101119704
Author(s):  
Moisés Edevaldo Pereira ◽  
Luciano Donizeti Varanda ◽  
Natália Rodrigues de Carvalho ◽  
Carlos Roberto Sette Jr ◽  
Franciane Andrade de Padua ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Residence Time ◽  
Broiler Chickens ◽  
Poultry Litter ◽  
Proximate Analysis ◽  
Ash Content ◽  
Residence Times ◽  
Heating Value ◽  
Scanning Electron

Brazil generates substantial quantity of poultry litter waste because of its worldwide prominence in the production of broiler chickens. The volume of the poultry litter biomass generates considerable environmental impact. The objective was to characterize the biochar produced from poultry litter residue under different conditions with the aim of determining the best residence time and temperature. Poultry litter was collected after two batches of chicken breeding. Five treatments for biochar production were carried out at a temperature of 450 °C (defined by thermogravimetric analysis - TGA) and residence times of 0.5, 1, 2, 4, and 6h. The biochar produced was assessed using proximate analysis, moisture content, gravimetric yield, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and HHV (higher heating value). The results revealed that the best conditions for biochar production was 450 °C (pyrolysis) and residence time of 0.5h, with 37.21% gravimetric yield. We concluded that the biochar produced in this study is recommended for soil application but was not suitable for energy purposes because of its high ash content (up to 33.66%) and low HHV (18,907 J g-1).

scholarly journals Karakteristik Struktur Mikro dan Gugus Fungsi Komposit Silika Sekam Padi dan Aspal

2020 ◽  
Vol 8 (1) ◽  
pp. 93-100
Author(s):  
Ediman Ginting Suka ◽  
◽  
Ira Sudarsono Putri ◽  
Reka Puspitasari ◽  
Reza Arsela ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Compressive Strength ◽  
Functional Groups ◽  
Amorphous Silica ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Sizes ◽  
Sample Composition ◽  
Scanning Electron

Composite of rice husk and asphalt silica was carried out at a ratio of 1: 0.7; 1: 0.8 and 1: 0.9 and heated at 150oC for 3 hours. The characteristics of the phase structure, microstructure, and functional groups were analyzed using X-ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) and Fourier Transform Infrared (FTIR), physical properties analysis (density, porosity) and mechanics (compressive strength). The XRD results showed that the phase in asphalt silica composites detected amorphous carbon at 2θ = 18º and amorphous silica with the amorphous silica peak shifted from 2θ = 22º to 2θ = 20º. Microstructure analysis shows that cracks and clusters are bigger with grain sizes of 7,742 µm, 8,495 µm and 10,921 µm respectively, and the sample composition shows percentage of silicon (Si), Oxygen (O) and sodium (Na), respectively. decreases and the percentage of carbon (C), sulfur (S) increases. The results of FTIR show that the functional groups of Si-OH, Si-O-Si and Si-O bonds are decreasing and the functional groups of C-H bonds are increasing. The addition of asphalt causes the value of density increases, the value of porosity and compressive strength decreases.

scholarly journals Cinnamyl-Imine-Chitosan Hydrogels. Morphology Control

2018 ◽  
Vol 26 (2) ◽  
pp. 221-232
Author(s):  
Anda M. Craciun
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Functional Groups ◽  
Molar Ratio ◽  
Crosslinking Degree ◽  
Molecular Weights ◽  
Amine Groups ◽  
Chitosan Hydrogels ◽  
Scanning Electron

Abstract The study deals with the exploration of the possibilities to control the morphology of cinnamyl-imine-chitosan hydrogels in view of their bio-application. Three series of hydrogels were synthetized from chitosan of three different molecular weights and cinnamaldehyde, varying the molar ratio between the amine groups on chitosan and aldehyde functional groups. The hydrogel morphology has been monitored by scanning electron microscopy. The variation of the hydrogel morphology as a function of chitosan molecular weight, crosslinking degree, and incubation conditions has been monitored. It was concluded that there are multiple possibilities of tuning the morphology of these hydrogels in function of the targeted application.

scholarly journals Blends of Polyimides and Their Morphology

2016 ◽  
Vol 6 (1) ◽  
pp. 17
Author(s):  
Saule Kudaikulova ◽  
Galina Boiko ◽  
Bulat Zhubanov ◽  
N. Ashurov ◽  
Sh. Sodykov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Functional Groups ◽  
Polymer Matrix ◽  
Single Step ◽  
Aromatic Diamines ◽  
X Ray ◽  
One Step ◽  
Scanning Electron

The formulation of macromolecular blends on the basis of polyimides using one step catalytic polycyclocondensation is reported. Polymers with active functional groups (polyacrylamide, polycaproamide) have been suggested as catalysts for the reaction of alicyclic dianhydrides with aromatic diamines in protolytic medium. Films made from macromolecular blends of synthesized polymers have been investigated by X-ray diffractometry and scanning electron microscopy. It has been shown that single step formation of polyimide on the polymer matrix presents the possibility to prepare thin structured disperse blends in comparison with simple mixing of homopolymers.

Reactivity Towards O2 and NO of the Soot Formed from Ethylene Pyrolysis at Different Temperatures

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
M Pilar Ruiz ◽  
Alicia Callejas ◽  
Angela Millera ◽  
María U. Alzueta ◽  
Rafael Bilbao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gas Chromatography ◽  
Raman Spectroscopy ◽  
Residence Time ◽  
Formation Temperature ◽  
Influence Of Temperature ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Scanning Electron

The influence of temperature on the formation of soot from ethylene pyrolysis has been studied. Pyrolysis experiments were carried out in a quartz reactor in the 1000-1200 °C temperature range, for an inlet C2H4 concentration of 50000 ppmv and a gas residence time of 4552/T(K) seconds. Outlet gases were analyzed by gas chromatography and the amount of soot produced measured. The reactivity of the soot samples obtained towards O2 and NO was also studied. Results show that the higher the formation temperature, the less reactive the soot. The soot samples were further characterized using elemental analysis, scanning electron microscopy and Raman spectroscopy, in order to study their structural properties, and relate them to their reactivity. Additionally, a comparison of the reactivity towards NO between acetylene and ethylene soot samples obtained under similar conditions has been carried out. The soot samples obtained from ethylene pyrolysis present higher reactivity towards NO than the soot samples formed from acetylene.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

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