Fabrication of chitosan/PEO nanofiber mats with mica by electrospinning

2017 ◽  
Vol 37 (5) ◽  
pp. 461-470 ◽  
Author(s):  
Qi Chen ◽  
Zhen Xiang Xin ◽  
Prosenjit Saha ◽  
Jin Kuk Kim
Keyword(s):  
Polyethylene Oxide ◽  
Weight Ratio ◽  
Tissue Scaffolds ◽  
Processing Conditions ◽  
Biological Applications ◽  
X Ray ◽  
Artificial Tissue ◽  
Antibacterial Material ◽  
Capillary Tip ◽  
Nanofiber Mats

Abstract Chitosan (CS) is an excellent biocompatible natural antibacterial material that has attracted researchers to study its biological applications as artificial tissue scaffolds and wound-healing materials. In this research, CS has been mixed with polyethylene oxide (PEO) and mica at various weight ratios to prepare nanofibers; however, it is found to be a difficult task to prepare the nanofiber using pure CS. The composite in form of nanofibrous mat was prepared with CS/PEO solution and CS/PEO/mica solution using electrospinning. Processing conditions were adjusted to a flow rate of 6 ml/min, with an applied voltage of 27 kV. The distance of capillary tip to target was kept about 10 cm at 25°C with a collector having a speed of 200 rpm. The spinnability of solutions was also evaluated by using both plate and cylinder collectors. The composite mats were analyzed in detail using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), thermogravimetric analysis, and X-ray diffractogram (XRD). SEM photomicrograms indicated that the morphology and diameter of the nanofibers were affected by weight ratio of CS/PEO, concentration of mica, and types of collector. Furthermore, mica was incorporated in the CS/PEO matrix to enhance the specific surface area. Molecular interactions between CS/PEO and mica were investigated using FTIR and XRD.

Mixed Micelle-Template Route to Mesoporous Silica

2007 ◽  
Vol 7 (11) ◽  
pp. 3819-3822 ◽  
Author(s):  
You-Hwan Son ◽  
Man Park ◽  
Sang Tae Kim ◽  
Jin-Ho Choy
Keyword(s):  
Mesoporous Silica ◽  
Polyethylene Oxide ◽  
Mixed Micelle ◽  
Weight Ratio ◽  
Mesoporous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Mcf 7

Mesoporous silica materials were prepared through a novel mixed micelle-template method which was employed by alkyl polyethylene oxide (C16E20 and C2-ceramide. X-ray diffraction patterns clearly showed the formation of mesoporous silica by contribution of mixed micelle-template up to 3/1 weight ratio (C16E20/C2-ceramide). TEM and N2 adsorption isotherms analyses indicated that the mesoporous structure was maintained even after encased C2-ceramides. However, when the weight ratio of C16E20/C2-ceramide exceeds 2/2, less ordered and irregular pore structure was observed. According to the in-vitro experiment on cancer cells such as MCF-7, HOS, and HepG2, the simultaneously encapsulated C2-ceramide shows apoptosis. Therefore, the present results could provide a new method for mesoporous material as drug delivery system.

Effect of nanofibrous porosity on the X-ray attenuation properties of electrospun n-Bi2O3/epoxy–polyvinyl alcohol (PVA) nanofiber mats

2018 ◽  
Vol 124 (8) ◽  
Author(s):  
Bassam M. Abunahel ◽  
Ramzun Maizan Ramli ◽  
Khetam M. Quffa ◽  
Nurul Zahirah Noor Azman
Keyword(s):  
Polyvinyl Alcohol ◽  
X Ray ◽  
Nanofiber Mats

Hydrophilicity of electrospun microfibers of polyethylene oxide with semisoluble polyaniline for biological applications

2021 ◽  
pp. 50740
Author(s):  
Rosario Ramírez ◽  
Ma. Guadalupe Olayo ◽  
J. Cuauhtemoc Palacios ◽  
Fernando G. Flores ◽  
Maribel González Torres ◽  
...  
Keyword(s):  
Polyethylene Oxide ◽  
Biological Applications

Effect of Boron and Carbon Addition on the Phase Transformations during High-Energy Ball Milling and Subsequent Sintering of Si3N4+B and Si3N4+C Powder Mixtures

2016 ◽  
Vol 869 ◽  
pp. 58-63
Author(s):  
Luiz Otávio Vicentin Maruya ◽  
Bruna Rage Baldone Lara ◽  
Belmira Benedita de Lima ◽  
Vanessa Motta Chad ◽  
Gilberto Carvalho Coelho ◽  
...  
Keyword(s):  
Phase Transformations ◽  
Ball Milling ◽  
Weight Ratio ◽  
High Energy ◽  
Ceramic Composites ◽  
Nitrogen Atmosphere ◽  
Carbon Addition ◽  
Powder Mixtures ◽  
X Ray ◽  
Milled Powders

This study reports on effect of boron and carbon addition on the phase transformations during ball milling and subsequent sintering of Si3N4+B and Si3N4+C powder mixtures. Ball milling at room temperature was conducted using stainless steel vials (225 mL) and balls (19mm diameter), 300 rpm and a bal-to-powder weight ratio of 10:1. The as-milled powders were uniaxially compacted in order to obtain cylinder samples with 10 mm diameter, which were subsequently sintered under nitrogen atmosphere at 1500°C for 1h. Characterization of the as-milled powders and sintered samples was performed by X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. Only peaks of Si3N4 were identified in X-ray diffractograms of as-milled Si3N4+B and Si3N4+C powders, suggesting that metastable structures were found during milling. After sintering at 1500°C for 1h, the Si3N4+BN and Si3N4+SiC ceramic composites were formed from the mechanically alloyed Si3N4+B and Si3N4+C powders.

Three-dimensional X-ray microtomography for medical and biological applications

1990 ◽  
Vol 35 (7) ◽  
pp. 805-820 ◽  
Author(s):  
E J Morton ◽  
S Webb ◽  
J E Bateman ◽  
L J Clarke ◽  
C G Shelton
Keyword(s):  
Three Dimensional ◽  
Biological Applications ◽  
X Ray

A flow cell forin situsynchrotron x-ray diffraction studies of scale formation under Bayer processing conditions

2009 ◽  
Vol 80 (8) ◽  
pp. 084102 ◽  
Author(s):  
Nathan A. S. Webster ◽  
Ian C. Madsen ◽  
Melissa J. Loan ◽  
Nicola V. Y. Scarlett ◽  
Kia S. Wallwork
Keyword(s):  
Flow Cell ◽  
Scale Formation ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
X Ray

Synthesis and characterisation of transition metal substituted barium hollandite ceramics

2006 ◽  
Vol 932 ◽  
Author(s):  
Neil C. Hyatt ◽  
Martin C. Stennett ◽  
Steven G. Fiddy ◽  
Jayne S. Wellings ◽  
Sian S. Dutton ◽  
...  
Keyword(s):  
Transition Metal ◽  
Oxidation State ◽  
Powder Diffraction ◽  
Single Phase ◽  
Maximum Density ◽  
Processing Conditions ◽  
Metal Oxidation ◽  
Exafs Data ◽  
X Ray ◽  
Oxygen Atoms

ABSTRACTA range of transition metal bearing hollandite phases, formulated Ba1.2B1.2Ti6.8O16 (B2+ = Mg, Co, Ni, Zn, Mn) and Ba1.2B2.4Ti5.6O16 (B3+ = Al, Cr, Fe) were prepared using an alkoxide - nitrate route. X-ray powder diffraction demonstrated the synthesis of single phase materials for all compositions except B = Mn. The processing conditions required to produce > 95 % dense ceramics were determined for all compositions, except B = Mg for which the maximum density obtained was > 93 %. Analysis of transition metal K-edge XANES data confirmed the presence of the targeted transition metal oxidation state for all compositions except B = Mn, where the overall oxidation state was found to be Mn3+. The K-edge EXAFS data of Ba1.2B1.2Ti6.8O16 (B = Ni and Co) were successfully analysed using a crystallographic model of the hollandite structure, with six oxygen atoms present in the first co-ordination shell at a distance of ca. 2.02Å. Analysis of Fe K-edge EXAFS data of Ba1.2B2.4Ti5.4O16 revealed a reduced co-ordination shell of five oxygens at ca. 1.99Å.

Surface properties and adsorption characteristics to methylene blue and iodine of adsorbents from sludge

2010 ◽  
Vol 62 (8) ◽  
pp. 1705-1712 ◽  
Author(s):  
L. Y. Deng ◽  
G. R. Xu ◽  
G. B. Li
Keyword(s):  
Methylene Blue ◽  
Electrostatic Interactions ◽  
Active Sites ◽  
Pyrolysis Temperature ◽  
Weight Ratio ◽  
Surface Characteristics ◽  
Wastewater Sludge ◽  
X Ray ◽  
Adsorption Characteristics ◽  
Adsorbent Surface

Adsorbent materials created from wastewater sludge have unique surface characteristics and could be effective in adsorption applications. In this research, the sludge-adsorbents were generated by pyrolyzing mixtures of sewage sludge and H2SO4. Scanning electron microscope (SEM), thermal analysis, X-ray diffraction (XRD) and X-ray photoelectron spectroscope (XPS) were used to analyze the properties of sludge-adsorbent. XPS results show that the adsorbent surface functional groups with high contents of oxygen-containing groups serve as active sites for the adsorption and affect the surface characteristics; the adsorption mechanism of methylene blue (MB) is mainly Brönsted acid-base reaction between the adsorbent surface and MB; and iodine atoms are bonded to the surface of the adsorbent mainly by dispersive interactions rather than by electrostatic interactions. The results also show that H2SO4 level, pyrolysis temperature and sulfuric acid/sludge weight ratio actually affected the adsorption characteristics. Using the conditions (H2SO4 level of 1–18 M, pyrolysis temperature of 650°C, and weight ratio of 0.8), the adsorption capacities for MB and iodine were 74.7–62.3 mg g−1 and 169.5–209.3 mg g−1, respectively.

Study of fossil bones by synchrotron radiation micro-spectroscopic techniques and scanning electron microscopy

2013 ◽  
Vol 21 (1) ◽  
pp. 149-160 ◽  
Author(s):  
I. M. Zougrou ◽  
M. Katsikini ◽  
F. Pinakidou ◽  
E. C. Paloura ◽  
L. Papadopoulou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Weight Ratio ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
Osteocyte Lacunae ◽  
Fossil Bones ◽  
Bone Apatite ◽  
Scanning Electron

Earlymost Villafranchian fossil bones of an artiodactyl and a perissodactyl from the Milia excavation site in Grevena, Greece, were studied in order to evaluate diagenetic effects. Optical microscopy revealed the different bone types (fibro-lamellar and Haversian, respectively) of the two fragments and their good preservation state. The spatial distribution of bone apatite and soil-originating elements was studied using micro-X-ray fluorescence (µ-XRF) mapping and scanning electron microscopy. The approximate value of the Ca/P ratio was 2.2, as determined from scanning electron microscopy measurements. Bacterial boring was detected close to the periosteal region and Fe bearing oxides were found to fill bone cavities,e.g.Haversian canals and osteocyte lacunae. In the perissodactyl bone considerable amounts of Mn were detected close to cracks (the Mn/Fe weight ratio takes values up to 3.5). Goethite and pyrite were detected in both samples by means of metallographic microscopy. The local Ca/P ratio determined with µ-XRF varied significantly in metal-poor spots indicating spatial inhomogeneities in the ionic substitutions. XRF line scans that span the bone cross sections revealed that Fe and Mn contaminate the bones from both the periosteum and medullar cavity and aggregate around local maxima. The formation of goethite, irrespective of the local Fe concentration, was verified by the FeK-edge X-ray absorption fine structure (XAFS) spectra. Finally, SrK-edge extended XAFS (EXAFS) revealed that Sr substitutes for Ca in bone apatite without obvious preference to the Ca1or Ca2unit-cell site occupation.

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