Structure and Properties of Cobaltous Chloride/Polyvinyl Alcohol-Glutaraldehyde(CC/PVA-GA) Reversible Thermochromic Microcapsule

2012 ◽  
Vol 501 ◽  
pp. 231-236 ◽  
Author(s):  
Jie Gao ◽  
Ping Guan ◽  
Xiao Ling Hu ◽  
Mei Cao
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Polyvinyl Alcohol ◽  
Interfacial Polymerization ◽  
Water Phase ◽  
Structure And Properties ◽  
Multiple Emulsion ◽  
Solvent Resistance ◽  
Cobaltous Chloride ◽  
External Water

The low-temperature reversible thermochromic microcapsules was prepared by interfacial polymerization, which an aqueous phase containing CoCl2 was used as the internal water phase (W1), cyclohexane was used as the oil phase (O), polyvinyl alcohol was used as the external water phase (W2) to form the uniform W1/O/W2 multiple emulsion. The structures of microcapsules were investigated using infrared spectrum (IR), electron microscopy (SEM) and polarization microscope. The properties of microcapsules, such as thermochromism and solvent resistance were also investigated. The results presented that the particle size of capsules was uniform, their walls were transparency, and the microcapsules were provided with excellent sensitivity to heat, reversibility and solvent resistance.

Synthesis, Structure and Properties of Super Fine LiMn2O4

2010 ◽  
Vol 177 ◽  
pp. 9-11 ◽  
Author(s):  
Jie Song ◽  
Bing Xu ◽  
De Xin Huang ◽  
Cai Xia Li ◽  
Qiang Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Electrode Material ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Mechanochemical Method ◽  
X Ray ◽  
Size And Morphology ◽  
Scanning Electron

In this paper, super fine LiMn2O4 powder was synthesized by mechanochemical method starting from Li2CO3 and Mn2O3. The structure, size and morphology of LiMn2O4 were explored with X-ray diffraction and scanning electron microscopy (SEM). The electrochemical properties of LiMn2O4 were studied in 2 mol/L (NH4)2SO4 solution. The result showed that pure spinel LiMn204 powder was prepared after 8h grinding with 3.0KW of power and the particle size was about 1µm. Cyclic vohammetry curve indicate LiMn2O4 electrode material has better capacitive performances.

Preparation and Application of VE Microcapsules with Polyurethane Shell for Skin-Care Textiles

2011 ◽  
Vol 331 ◽  
pp. 402-406 ◽  
Author(s):  
Guo Ping Yao ◽  
Jin Huan Zheng ◽  
Hui Fen Chen
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Vitamin E ◽  
Interfacial Polymerization ◽  
Chain Extender ◽  
Skin Care ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Skin Care Product ◽  
The Mean

Vitamin E (VE) microcapsules with polyurethane (PU) shell are successfully prepared via interfacial polymerization of polyurethane with toluene-2,4-diisocyanate (TDI) as the isocyanate, polyethylene glycol as the polyol, and 1,4-butanediol (BD) as the chain extender. In the preparation process, VE emulsion, prepolymer and microencapsulation of VE are studied using a particle size analyzer, butylamine titration, optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Based on the present research, VE microcapsules prepared have smooth surfaces and spherical appearances, the mean particle size of about 550 nm. Vitamin E microcapsules have been glued effectively to textiles, and a kind of skin-care product has been developed.

The Structure and Properties of NBR / Recycled Polytetrafluoroethylene (R-PTFE) Composites

2014 ◽  
Vol 983 ◽  
pp. 152-155
Author(s):  
Wen Wen Chen ◽  
Chang Lin Cao ◽  
Yi Zhang ◽  
Li Ren Xiao ◽  
Qing Rong Qian ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Structure And Properties ◽  
Solvent Resistance ◽  
Properties Of Materials ◽  
Ptfe Composites ◽  
Positive Effect

The structure and properties of NBR and its composites coupled with different particle size of recycled polytetrafluoetylene (R-PTFE) are investigated. The results show that R-PTFE has a positive effect on NBR enhancing the curing properties of materials, mechanical properties, solvent resistance of NBR when the particle size of R-PTFE less than 200 mesh. However, when it is 200 mesh, R-PTFE is not easily dispersed in the NBR matrix, resulting in decreasing the properties of NBR/R-PTFE composites.

Structure and Properties Analysis of Microcapsulated Capsaicin Prepared by Diphase Emulsion Method

2011 ◽  
Vol 239-242 ◽  
pp. 3182-3185 ◽  
Author(s):  
Jin Cheng Wang ◽  
Si Hao Chen ◽  
Shan Zhong Xu ◽  
Ye Xue ◽  
Jian Zhong Lou
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Structure And Properties ◽  
Scanning Calorimetry ◽  
Emulsion Method ◽  
Particle Size Analyzer ◽  
Mean Diameter ◽  
Scanning Electron

With polylactic acid (PLA) resin as walls and capsaicin as core substances, microcapsules were prepared based on diphase emulsion method. The microcapsule characteristics such as the particle size, inner structure and properties were investigated. The morphology and size distribution of the microcapsules were analyzed by laser particle size analyzer and scanning electron microscopy (SEM). The microcapsules had a mean diameter of about 60~120 µm. In addition, their thermal properties were measured by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was demonstrated that the melting point and thermal stability were improved or changed compared with that of the pure capsaicin. These phenomena were caused by the encapsulated PLA resin over the surface.

Analytical Electron Microscopy study of two vehicle-aged automotive exhaust catalysts having dissimilar activities

1989 ◽  
Vol 47 ◽  
pp. 272-273
Author(s):  
Sooho Kim ◽  
M. J. D’Aniello
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Noble Metal ◽  
Catalyst Deactivation ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Metal Particles ◽  
Automotive Exhaust ◽  
Exhaust Catalysts ◽  
Analytical Electron

Automotive catalysts generally lose-agtivity during vehicle operation due to several well-known deactivation mechanisms. To gain a more fundamental understanding of catalyst deactivation, the microscopic details of fresh and vehicle-aged commercial pelleted automotive exhaust catalysts containing Pt, Pd and Rh were studied by employing Analytical Electron Microscopy (AEM). Two different vehicle-aged samples containing similar poison levels but having different catalytic activities (denoted better and poorer) were selected for this study.The general microstructure of the supports and the noble metal particles of the two catalysts looks similar; the noble metal particles were generally found to be spherical and often faceted. However, the average noble metal particle size on the poorer catalyst (21 nm) was larger than that on the better catalyst (16 nm). These sizes represent a significant increase over that found on the fresh catalyst (8 nm). The activity of these catalysts decreases as the observed particle size increases.

Preparation, Characterization and In-vitro release of Piroxicam-loaded Solid Lipid Nanoparticles

2010 ◽  
Vol 3 (3) ◽  
pp. 1136-1146
Author(s):  
V K Verma ◽  
Ram A
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Solid Lipid Nanoparticles ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
Lipid Nanoparticles ◽  
Diffusion Method ◽  
Solid Lipid ◽  
Vitro Release

 Solid lipid nanoparticles (SLNs) of piroxicam where produced by solvent emulsification diffusion method in a solvent saturated system. The SLNs where composed of tripamitin lipid, polyvinyl alcohol (PVAL) stabilizer, and solvent ethyl acetate. All the formulation were subjected to particle size analysis, zeta potential, drug entrapment efficiency, percent drug loading determination and in-vitro release studies. The SLNs formed were nano-size range with maximum entrapment efficiency. Formulation with 435nm in particle size and 85% drug entrapment was subjected to scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for surface morphology, differential scanning calorimetry (DSC) for thermal analysis and short term stability studies. SEM and TEM confirm that the SLNs are nanometric size and circular in shape. The drug release behavior from SLNs suspension exhibited biphasic pattern with an initial burst and prolong release over 24 h. 

Isolasi Dan Karakterisasi Bentonit Alam Menjadi Nanopartikel Monmorillonit

2018 ◽  
Vol 3 (1) ◽  
pp. 12 ◽  
Author(s):  
Zaimahwati Zaimahwati ◽  
Yuniati Yuniati ◽  
Ramzi Jalal ◽  
Syahman Zhafiri ◽  
Yuli Yetri
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Surface Morphology ◽  
Average Diameter ◽  
Particle Size Analyzer ◽  
Ft Ir ◽  
Scanning Electron ◽  
Sedimentation Processes

<p>Pada penelitian ini telah dilakukan isolasi dan karakterisasi bentonit alam menjadi nanopartikel montmorillonit. Bentonit alam yang digunakan diambil dari desa Blangdalam, Kecamatan Nisam Kabupaten Aceh Utara.  Proses isolasi meliputi proses pelarutan dengan aquades, ultrasonic dan proses sedimentasi. Untuk mengetahui karakterisasi montmorillonit dilakukan uji FT-IR, X-RD dan uji morfologi permukaan dengan Scanning Electron Microscopy (SEM). Partikel size analyzer untuk menganalisis dan menentukan ukuran nanopartikel dari isolasi bentonit alam. Dari hasil penelitian didapat ukuran nanopartikel montmorillonit hasil isolasi dari bentonit alam diperoleh berdiameter rata-rata 82,15 nm.</p><p><em>In this research we have isolated and characterized natural bentonite into montmorillonite nanoparticles. Natural bentonite used was taken from Blangdalam village, Nisam sub-district, North Aceh district. The isolation process includes dissolving process with aquades, ultrasonic and sedimentation processes.  The characterization of montmorillonite, FT-IR, X-RD and surface morphology test by Scanning Electron Microscopy (SEM). Particle size analyzer to analyze and determine the size of nanoparticles from natural bentonite insulation. From the research results obtained the size of montmorillonite nanoparticles isolated from natural bentonite obtained an average diameter of 82.15 nm.</em></p>

scholarly journals Viscoelastic Polyurethane Foam with Keratin and Flame-Retardant Additives

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1380
Author(s):  
Krystyna Wrześniewska-Tosik ◽  
Joanna Ryszkowska ◽  
Tomasz Mik ◽  
Ewa Wesołowska ◽  
Tomasz Kowalewski ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermal Resistance ◽  
Flame Retardant ◽  
Fire Resistance ◽  
Release Rate ◽  
Structure And Properties ◽  
Burning Behavior ◽  
Keratin Fibers ◽  
Scanning Electron

Viscoelastic polyurethane (VEPUR) foams with increased thermal resistance are presented in this article. VEPUR foams were manufactured with the use of various types of flame retardant additives and keratin fibers. The structure of the modified foams was determined by spectrophotometric-(FTIR), thermal-(DSC), and thermogravimetric (TGA) analyses as well as by scanning electron microscopy (SEM). We also assessed the fire resistance, hardness, and comfort coefficient (SAG factor). It was found that the use of keratin filler and flame retardant additives changed the foams’ structure and properties as well as their burning behavior. The highest fire resistance was achieved for foams containing keratin and expanding graphite, for which the reduction in heat release rate (HRR) compared to VEPUR foams reached 75%.

scholarly journals A Thermally Conductive Pt/AAO Catalyst for Hydrogen Passive Autocatalytic Recombination

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 491
Author(s):  
Alina E. Kozhukhova ◽  
Stephanus P. du Preez ◽  
Aleksander A. Malakhov ◽  
Dmitri G. Bessarabov
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Combustion Temperature ◽  
Volume Fraction ◽  
Morphological Characteristics ◽  
Al Alloy ◽  
Impregnation Method ◽  
Case Scenario ◽  
Worst Case ◽  
Thermal Distribution

In this study, a Pt/anodized aluminum oxide (AAO) catalyst was prepared by the anodization of an Al alloy (Al6082, 97.5% Al), followed by the incorporation of Pt via an incipient wet impregnation method. Then, the Pt/AAO catalyst was evaluated for autocatalytic hydrogen recombination. The Pt/AAO catalyst’s morphological characteristics were determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The average Pt particle size was determined to be 3.0 ± 0.6 nm. This Pt/AAO catalyst was tested for the combustion of lean hydrogen (0.5–4 vol% H2 in the air) in a recombiner section testing station. The thermal distribution throughout the catalytic surface was investigated at 3 vol% hydrogen (H2) using an infrared camera. The Al/AAO system had a high thermal conductivity, which prevents the formation of hotspots (areas where localized surface temperature is higher than an average temperature across the entire catalyst surface). In turn, the Pt stability was enhanced during catalytic hydrogen combustion (CHC). A temperature gradient over 70 mm of the Pt/AAO catalyst was 23 °C and 42 °C for catalysts with uniform and nonuniform (worst-case scenario) Pt distributions. The commercial computational fluid dynamics (CFD) code STAR-CCM+ was used to compare the experimentally observed and numerically simulated thermal distribution of the Pt/AAO catalyst. The effect of the initial H2 volume fraction on the combustion temperature and conversion of H2 was investigated. The activation energy for CHC on the Pt/AAO catalyst was 19.2 kJ/mol. Prolonged CHC was performed to assess the durability (reactive metal stability and catalytic activity) of the Pt/AAO catalyst. A stable combustion temperature of 162.8 ± 8.0 °C was maintained over 530 h of CHC. To confirm that Pt aggregation was avoided, the Pt particle size and distribution were determined by TEM before and after prolonged CHC.

scholarly journals Functional Properties and Molecular Degradation of Schizostachyum Brachycladum Bamboo Cellulose Nanofibre in PLA-Chitosan Bionanocomposites

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2008
Author(s):  
Samsul Rizal ◽  
N. I. Saharudin ◽  
N. G. Olaiya ◽  
H. P. S. Abdul Khalil ◽  
M. K. Mohamad Haafiz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Moisture Content ◽  
Polymeric Materials ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Thickness Swelling ◽  
Compression Moulding ◽  
Ft Ir ◽  
Degradation Properties

The degradation and mechanical properties of potential polymeric materials used for green manufacturing are significant determinants. In this study, cellulose nanofibre was prepared from Schizostachyum brachycladum bamboo and used as reinforcement in the PLA/chitosan matrix using melt extrusion and compression moulding method. The cellulose nanofibre(CNF) was isolated using supercritical carbon dioxide and high-pressure homogenisation. The isolated CNF was characterised with transmission electron microscopy (TEM), FT-IR, zeta potential and particle size analysis. The mechanical, physical, and degradation properties of the resulting biocomposite were studied with moisture content, density, thickness swelling, tensile, flexural, scanning electron microscopy, thermogravimetry, and biodegradability analysis. The TEM, FT-IR, and particle size results showed successful isolation of cellulose nanofibre using this method. The result showed that the physical, mechanical, and degradation properties of PLA/chitosan/CNF biocomposite were significantly enhanced with cellulose nanofibre. The density, thickness swelling, and moisture content increased with the addition of CNF. Also, tensile strength and modulus; flexural strength and modulus increased; while the elongation reduced. The carbon residue from the thermal degradation and the glass transition temperature of the PLA/chitosan/CNF biocomposite was observed to increase with the addition of CNF. The result showed that the biocomposite has potential for green and sustainable industrial application.

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