Preparation of UV Curable Waterborne Polyurethane and its Application in Coatings

2013 ◽  
Vol 821-822 ◽  
pp. 925-928
Author(s):  
Lei Wang ◽  
Xiao Juan Lai ◽  
Shao Yun Ma
Keyword(s):  
Electron Microscopy ◽  
Water Resistance ◽  
Waterborne Polyurethane ◽  
Water Soluble ◽  
Cross Linking ◽  
Crosslinking Degree ◽  
Uv Curable ◽  
Transmission Electron ◽  
Solidification Reaction ◽  
Test Result

Waterborne UV curable polyurethane emulision containing C=C bond was prepared with self-emulsification. 3% water soluble photoinitiator was added to the polyurethane emulision, and polyurethane films was prepared by ultraviolet irradiation. The structure of the polyurethane emulision and films were confirmed by means of Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and thermogravimetric analysis. FTIR test result shows that cross linking and solidification reaction of C=C double bond happened after UV irradiation. When C=C content increases, the particle size of polyurethane emulision increases, crosslinking degree of films increases, water resistance and heat resistance have both been improved. When C=C content is 8.51%, gel content is more than 90% and the lowest water absorption can be 12.5%.

Electrospinning Fabrication of Polyvinyl alcohol)/Waterborne Polyurethane/Silver Composite Nanofibre Mats in Aqueous Solution for Anti-bacterial Exploits

2011 ◽  
Vol 19 (9) ◽  
pp. 753-762 ◽  
Author(s):  
Jae Hyeung Park ◽  
In Kyo Kim ◽  
Jae Young Choi ◽  
Mohammad Rezaul Karim ◽  
In Woo Cheong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Transmission Electron Microscopy ◽  
Waterborne Polyurethane ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Biocompatible Polymer ◽  
Transmission Electron ◽  
Electrospinning Method ◽  
Silver Composite

Nanofibre mats of poly(vinyl alcohol) (PVA), waterborne polyurethane (WBPU) and nanometre silver (Ag) colloids have been fabricated by an electrospinning method in aqueous solutions. Since PVA is a water soluble and biocompatible polymer, it is one of the best materials for preparation of electrospun antibacterial nanofibre mats. WBPU was used as a filler to enhance the properties of homopolymer nanofibre. Transmission electron microscopy analyses showed a uniform distribution of silver in the fibres. In anti-bacterial tests, the PVA/WBPU/Ag composite nanofibres showed excellent anti-bacterial performance, indicating practical uses as a new preservative. Moreover, the PVA/WBPU/Ag nanofibres showed improved thermal properties.

Embedding Procedure for Water Swollen Samples

1970 ◽  
Vol 28 ◽  
pp. 504-505
Author(s):  
Ann M. Thomas ◽  
Virginia Shemeley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Exchange ◽  
Structural Changes ◽  
Cross Linking ◽  
Ion Exchange Resins ◽  
Transmission Electron ◽  
First Pass ◽  
Exchange Resins

Those samples which swell rapidly when exposed to water are, at best, difficult to section for transmission electron microscopy. Some materials literally burst out of the embedding block with the first pass by the knife, and even the most rapid cutting cycle produces sections of limited value. Many ion exchange resins swell in water; some undergo irreversible structural changes when dried. We developed our embedding procedure to handle this type of sample, but it should be applicable to many materials that present similar sectioning difficulties.The purpose of our embedding procedure is to build up a cross-linking network throughout the sample, while it is in a water swollen state. Our procedure was suggested to us by the work of Rosenberg, where he mentioned the formation of a tridimensional structure by the polymerization of the GMA biproduct, triglycol dimethacrylate.

Synthesis and Characterization of Water-Soluble Monolayer-Protected Gold Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Transmission Electron

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

Facile synthesis of water-soluble graphene-based composite: Non-covalently functionalized with chitosan-ionic liquid conjugation

2016 ◽  
Vol 09 (03) ◽  
pp. 1650045 ◽  
Author(s):  
Pei-Ying Li ◽  
Kai-Yu Cheng ◽  
Xiu-Cheng Zheng ◽  
Pu Liu ◽  
Xiu-Juan Xu
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Chemical Reduction ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Text Interaction

Chitosan-ionic liquid conjugation (CILC), which was prepared through the reaction of 1-(4-bromobutyl)-3-methylimidazolium bromide (BBMIB) with chitosan, was firstly used to prepare functionalized graphene composite via the chemical reduction of graphene oxide (GO). The obtained water soluble graphene-based composite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultraviolet-visible (UV–Vis) spectroscopy and so on. CILC-RGO showed excellent dispersion stability in water at the concentration of 2.0 mg/mL, which was stable for several months without any precipitate. This may be ascribed to the electrostatic attraction and [Formula: see text]–[Formula: see text] interaction between CILC and graphene.

Water resistance of the membranes for UV curable waterborne polyurethane dispersions

2007 ◽  
Vol 59 (4) ◽  
pp. 331-336 ◽  
Author(s):  
Chen Yan Bai ◽  
Xing Yuan Zhang ◽  
Jia Bing Dai ◽  
Chu Yin Zhang
Keyword(s):  
Water Resistance ◽  
Waterborne Polyurethane ◽  
Uv Curable ◽  
Polyurethane Dispersions

Mono Dispersable Water-Soluble Iron Sulfide Nanoclusters: Synthesis, Characterization and Catalytic Application for Highly Efficient Synthesis of Xanthene Derivatives

2020 ◽  
Vol 12 (5) ◽  
pp. 603-611
Author(s):  
Kumar Karitkey Yadav ◽  
Hemant Kumar ◽  
Balaram Pani ◽  
Indrajit Roy ◽  
Pramod Kumar
Keyword(s):  
Electron Microscopy ◽  
Iron Sulfide ◽  
Reaction Times ◽  
Current Method ◽  
Nitrogen Adsorption ◽  
Significant Loss ◽  
Water Soluble ◽  
Precipitation Reaction ◽  
Transmission Electron ◽  
Xanthene Derivatives

In this manuscript, we have synthesized Iron sulfide nanoclusters (FeSNCs) by precipitation reaction between ferric chloride (FeCl3 · 6H2O) and thiourea with sodium borohydride (NaBH4) as a reducing agent at room temperature in water. These nanoclusters are synthesized within two minutes. The morphology and size of these synthesized FeSNCs were confirmed from transmission electron microscopy (TEM) and scanning electron microscopy (SEM). TEM and SEM data showed that the average diameters of these FeSNCs are around 70 nm. The Power X-ray diffraction (XRD) patten of the FeSNCs clearly showed the crystalline nature of these nanoclusters. Vibrating sample magnetometer (VSM) experiment showed that these nanoclusters are ferromagnetic in nature having high magnetization (20 emu/g). The nitrogen adsorption isotherm of FeSNCs confirmed the porous nature. These well characterized FeSNCs were further utilized as a catalyst for the synthesis of 9-aryl-1,8-dioxooctahydroxanthenes and 14-substituted-14H-dibenzo[a, j] xanthene derivatives. It is observed that the catalytic activities of FeSNCs are much better than the other reported heterogeneous and homogeneous catalysts. After completion of the reaction, FeSNCs are separated from the reaction mixture with the help bar magnet, washed and reused for the next catalytic reaction. Current method offers several advantages over other reported methods such as excellent yields, short reaction times, simple reaction procedure, and reusability of the catalyst upto five times without any significant loss in its activity.

scholarly journals Self-assembly of chiral fluorescent nanoparticles based on water-soluble L-tryptophan derivatives of p-tert-butylthiacalix[4]arene

2017 ◽  
Vol 8 ◽  
pp. 1825-1835 ◽  
Author(s):  
Pavel L Padnya ◽  
Irina A Khripunova ◽  
Olga A Mostovaya ◽  
Timur A Mukhametzyanov ◽  
Vladimir G Evtugyn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Water Soluble ◽  
Fluorescent Nanoparticles ◽  
Spectral Emission ◽  
Chiroptical Properties ◽  
Transmission Electron ◽  
Derivatives Of ◽  
Tryptophan Derivatives ◽  
Positively Charged

New water-soluble tetra-substituted derivatives of p-tert-butylthiacalix[4]arene containing fragments of L-tryptophan in cone and 1,3-alternate conformations were obtained. It was shown that the resulting compounds form stable, positively charged aggregates of 86–134 nm in diameter in water at a concentration of 1 × 10−4 M as confirmed by dynamic light scattering, scanning electron microscopy and transmission electron microscopy. It was established that these aggregates are fluorescently active and chiral. A distinctive feature of the compounds is the pronounced dependence of their spectral (emission and chiroptical) properties on the polarity of the solvent and the length of the linker between the macrocyclic and fluorophore parts of the molecule.

A NOVEL SYNTHESIS ROUTE TO BIO-FUNCTIONALIZED AND MAGNETICALLY ADDRESSABLE FERROGELS

2013 ◽  
Vol 27 (32) ◽  
pp. 1350239
Author(s):  
SAMRAT MUKHERJEE ◽  
JAYDIP BASU ◽  
DIPANKAR DAS
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Linking ◽  
Dc Magnetization ◽  
Long Period ◽  
Novel Synthesis ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Average Size ◽  
High Pressure Environment

In this paper, ferrogels comprising nanocrystalline Fe 3 O 4 and γ- FeOOH dispersed in polyvinyl alcohol gel matrix were synthesized via a novel route, without using any cross-linking agent. A moderately high-pressure environment instead was used for the synthesis. The ferrogels were found to be stable over a long period of time and were characterized by transmission electron microscopy (TEM), Mössbauer spectroscopy and DC magnetization studies. TEM studies showed that the particles are mostly spherical with an average size of 10 nm. Mössbauer spectra of the as prepared gels at different temperatures showed the presence of superparamagnetic particles in them. The gels were found to be magnetically ordered at 20 K giving characteristic six-finger Mössbauer patterns. Bulk magnetic properties of the gels were studied by DC magnetization measurements.

scholarly journals Formation of Hirano Bodies Induced by Expression of an Actin Cross-Linking Protein with a Gain-of-Function Mutation

2003 ◽  
Vol 2 (4) ◽  
pp. 778-787 ◽  
Author(s):  
Andrew Maselli ◽  
Ruth Furukawa ◽  
Susanne A. M. Thomson ◽  
Richard C. Davis ◽  
Marcus Fechheimer
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cellular Response ◽  
Biological Function ◽  
Point Mutations ◽  
Actin Binding ◽  
Cross Linking ◽  
Hirano Bodies ◽  
Transmission Electron ◽  
Ef Hand

ABSTRACT Hirano bodies are paracrystalline actin filament-containing structures reported to be associated with a variety of neurodegenerative diseases. However, the biological function of Hirano bodies remains poorly understood, since nearly all prior studies of these structures were done with postmortem samples of tissue. In the present study, we generated a full-length form of a Dictyostelium 34-kDa actin cross-linking protein with point mutations in the first putative EF hand, termed 34-kDa ΔEF1. The 34-kDa ΔEF1 protein binds calcium normally but has activated actin binding that is unregulated by calcium. The expression of the 34-kDa ΔEF1 protein in Dictyostelium induces the formation of Hirano bodies, as assessed by both fluorescence microscopy and transmission electron microscopy. Dictyostelium cells bearing Hirano bodies grow normally, indicating that Hirano bodies are not associated with cell death and are not deleterious to cell growth. Moreover, the expression of the 34-kDa ΔEF1 protein rescues the phenotypes of cells lacking the 34-kDa protein and cells lacking both the 34-kDa protein and α-actinin. Finally, the expression of the 34-kDa ΔEF1 protein also initiates the formation of Hirano bodies in cultured mouse fibroblasts. These results show that the failure to regulate the activity and/or affinity of an actin cross-linking protein can provide a signal for the formation of Hirano bodies. More generally, the formation of Hirano bodies is a cellular response to or a consequence of aberrant function of the actin cytoskeleton.

scholarly journals Preparation and characterization of highly blue emitting fluorescent carbon nano-dots using Pongammia pinnata fresh leaves

2021 ◽  
Author(s):  
Govindaraju K ◽  
K. Vijai Anand ◽  
S. Muthamilselvan ◽  
M. Kannan ◽  
M. Elanchezhiyan
Keyword(s):  
Electron Microscopy ◽  
Water Soluble ◽  
Hydrothermal Technique ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Average Size ◽  
Soluble Carbon ◽  
Ft Ir Spectroscopy

Abstract In this study, a simple environmental benign approach have been adopted for the preparation of highly luminescent (blue emitting) water soluble carbon nano-dots using Pongammia pinnata (Pp) leaves via hydrothermal technique. The prepared Pp-carbon nano- dots were characterized using UV-vis spectroscopy, fluorescence spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements. The Pp-carbon nano-dots are spherical in shape with an average size of 32 nm.

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