The Preparation of O-Carboxymethyl-Chitosan and its Particles

2012 ◽  
Vol 490-495 ◽  
pp. 3782-3785 ◽  
Author(s):  
Xiao Xian Shang ◽  
Jiao Du ◽  
Hong Yan Zhang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Active Site ◽  
Carboxymethyl Chitosan ◽  
Cross Linking ◽  
Reaction Method ◽  
Alkaline Conditions ◽  
Amino Protection

The active site of chitosan is protected basing on amino reaction method of reaction between benzaldehyde and chitosan to form Schiff. The O-carboxymethyl chitosan is obtained by the method that taking chloroactic acid to hydroxyl of chitosan as modifier in alkaline conditions to form amino protection and then remove the protection in acid conditions. The O-carboxymethyl chitosan particles with particle size distribution of 15-50μm is prepared by emulsification cross- linking method.

scholarly journals Preparation of 3D Printable HAp-based Composite Powder for Binder Jetting Process

2020 ◽  
Author(s):  
Fahimeh Dini ◽  
Seyed Amir Ghaffari ◽  
Jafar Javadpour ◽  
Hamid Reza Rezaie
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Chitosan Solution ◽  
Carboxymethyl Chitosan ◽  
Water Soluble ◽  
Print Quality ◽  
Water Soluble Polymers ◽  
Printing Quality ◽  
Binder Jetting

Abstract The purpose of this study was to prepare a 3D printable powder composed of hydroxyapatite and biocompatible polymers such as chitosan, dextrin, and polyvinylpyrrolidone for the binder jetting process. The relationship between powder properties such as flowability and particle size distribution, as well as printing quality were investigated in the binder jetting process. For this purpose, 3D printable powder and an appropriate solvent were designed and demonstrated by hydroxyapatite and water-soluble polymers such as carboxymethyl chitosan, dextrin, and PVP. Results showed that a combination of 60%wt. hydroxyapatite, 28%wt. carboxymethyl chitosan, 10% wt. dextrin, and 2% wt. PVP, with controlled particle size distribution according to the Dinger-Funk equation led to the best print quality. Finally, flash dipping of the 3D printed parts in chitosan solution resulted in increases of compressive and Young's modulus from 1.3 and 10 MPa to 7.4 and 125 MPa, respectively.

The Investigations on Luminescence Characteristics and Influence of Doping and Co-Doping Different Rare Earth Ions in White Phosphorescence Materials Having Different Luminescent Centers

2014 ◽  
Vol 90 ◽  
pp. 133-140
Author(s):  
Erkul Karacaoglu ◽  
Bekir Karasu ◽  
Esra Öztürk
Keyword(s):  
Particle Size ◽  
Rare Earth ◽  
Solid State ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Rare Earths ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Luminescence Characteristics

The Akermanite type alkaline earth silicate Ca2MgSi2O7 activated by different types of rare earths was prepared by the conventional solid state reaction method under weak reductive atmosphere. The phase formation, particle size distribution, particle morphologies and photoluminescence properties of the samples have been investigated respectively. The comparative results of SEM and laser particle size analysis revealed that the relatively regular morphology, smaller particle size distribution could be achieved for the phosphors synthesized by the solid state reaction method including dry-ground after which powders were sieved below 170 meshes. The effects of rare earth oxides; Nd2O3, Pr6O11, Ce2O3 and Sm2O3 on the luminescence properties of the host material, Ca2MgSi2O7, were studied. Remarkable enhancement and novel color emitting including white in luminescence characteristics of host material were observed as a result of doping the mentioned rare-earths were doped.

Effects of Particle Size Distribution on Corrosion Rate of Carbon Steel in Soil

2020 ◽  
Vol 69 (4) ◽  
pp. 102-106
Author(s):  
Shota Ohki ◽  
Shingo Mineta ◽  
Mamoru Mizunuma ◽  
Soichi Oka ◽  
Masayuki Tsuda
Keyword(s):  
Particle Size ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Particle Size Distribution ◽  
Size Distribution

DENSE SPRAY CORRECTIONS FOR DIFFRACTION-BASED PARTICLE SIZE DISTRIBUTION MEASUREMENTS

1995 ◽  
Vol 5 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Christine M. Woodall ◽  
James E. Peters ◽  
Richard O. Buckius
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution

Influence of Cementite Particle Size Distribution on Machinability and Tool Life of High Carbon Cr-bearing Steels

1998 ◽  
Vol 84 (5) ◽  
pp. 387-392 ◽  
Author(s):  
Takashi INOUE ◽  
Yuzo HOSOI ◽  
Koe NAKAJIMA ◽  
Hiroyuki TAKENAKA ◽  
Tomonori HANYUDA
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Tool Life ◽  
Cementite Particle ◽  
High Carbon ◽  
Bearing Steels

Study of the microstructure and particles of vanadium (III) oxide, vanadium (V) oxide and lithium aluminate powders

2020 ◽  
Vol 86 (1) ◽  
pp. 32-37
Author(s):  
Valeria A. Brodskaya ◽  
Oksana A. Molkova ◽  
Kira B. Zhogova ◽  
Inga V. Astakhova
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Vanadium Oxide ◽  
Size Distribution ◽  
Microstructural Analysis ◽  
Coherent Scattering ◽  
Powder Materials ◽  
Lithium Aluminate ◽  
Range Limit ◽  
Oxide Particles

Powder materials are widely used in the manufacture of electrochemical elements of thermal chemical sources of current. Electrochemical behavior of the powders depends on the shape and size of their particles. The results of the study of the microstructure and particles of the powders of vanadium (III), (V) oxides and lithium aluminate obtained by transmission electron and atomic force microscopy, X-ray diffraction and gas adsorption analyses are presented. It is found that the sizes of vanadium (III) and vanadium (V) oxide particles range within 70 – 600 and 40 – 350 nm, respectively. The size of the coherent-scattering regions of the vanadium oxide particles lies in the lower range limit which can be attributed to small size of the structural elements (crystallites). An average volumetric-surface diameter calculated on the basis of the surface specific area is close to the upper range limit which can be explained by the partial agglomeration of the powder particles. Unlike the vanadium oxide particles, the range of the particle size distribution of the lithium aluminate powder is narrower — 50 – 110 nm. The values of crystallite sizes are close to the maximum of the particle size distribution. Microstructural analysis showed that the particles in the samples of vanadium oxides have a rounded (V2O3) or elongated (V2O5) shape; whereas the particles of lithium aluminate powder exhibit lamellar structure. At the same time, for different batches of the same material, the particle size distribution is similar, which indicates the reproducibility of the technologies for their manufacture. The data obtained can be used to control the constancy of the particle size distribution of powder materials.

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