Preparation and Structure Analysis of Noncrystalline Granular Starch

2010 ◽  
Vol 6 (4) ◽  
Author(s):  
Peiling Liu ◽  
Benshan Zhang ◽  
Qun Shen ◽  
Xiaosong Hu ◽  
Wenhao Li
Keyword(s):  
Thermal Treatment ◽  
Crystalline Structure ◽  
Chemical Method ◽  
Physical Method ◽  
Maize Starch ◽  
X Ray Diffraction ◽  
Preparation Methods ◽  
Peculiar Form ◽  
Freeze Dried ◽  
Better Than

Noncrystalline granular (NCG) starch is a peculiar form of starch. The granules have granular shape but no crystalline structure. It is a middle state between native semi-crystal structure and paste. The conception of NCG starch was presented and its preparation methods for native maize starch were explored. Cross-linking by chloroepoxy propane was adopted as the chemical method while ethanol treatment was adopted as the physical method. Cross bonds and ethanol were both able to protect starch granules from swelling while thermal treatment was able to destroy crystalline structure of the granules. The structure of granule was observed by polarization microscope and scanning electron microscopy (SEM). Change from crystalline to noncrystalline structure was confirmed by X-ray diffraction (XRD). It indicated that preparation of NCG starch with the physical method was better than chemical method. The detailed conditions were: maize starch (40%, w/w) was slurried in 50%-ethanol, underwent thermal treatment at 85°C for 2 minutes, washed with anhydrous ethanol (2000 ml), and freeze dried.

Progress in the Preparation of Silver Nanometer Antibacterial Material

2020 ◽  
Vol 996 ◽  
pp. 76-81
Author(s):  
Ben Jiao Li ◽  
Song Li ◽  
Bin Rong Ma ◽  
Yong Jing ◽  
Zhe Ming Zhang ◽  
...  
Keyword(s):  
Chemical Method ◽  
Antibacterial Agents ◽  
Antibacterial Properties ◽  
Physical Method ◽  
Biological Method ◽  
Preparation Methods ◽  
Antibacterial Materials ◽  
Development And Utilization ◽  
Antibacterial Material ◽  
Further Development

Silver inorganic antibacterial agents have been widely used inbiotechnology, bioengineering science, electronics, optics and water treatment because of their strong bactericidal ability, high safety and durable antibacterial properties. In this paper, the preparation methods of silver nanoparticles are reviewed, including physical method, chemical method and biological method, in order to provide a reference for the further development and utilization of silver nano-antibacterial materials.

Cathodoluminescence Quenching in Yb-Doped ZnO Nanostructures

2009 ◽  
Vol 5 ◽  
pp. 177-183 ◽  
Author(s):  
A. Susarrey-Arce ◽  
M. Herrera-Zaldívar ◽  
W. de la Cruz ◽  
Umapada Pal
Keyword(s):  
Energy Transfer ◽  
Thermal Treatment ◽  
Point Defects ◽  
Chemical Method ◽  
Oxygen Vacancies ◽  
Energy Transfer Process ◽  
Physical Method ◽  
Zno Nanostructures ◽  
Physical Methods ◽  
Doped Zno

Cathodoluminescence (CL) quenching was observed in ZnO nanostructures when doped with Yb by both chemical and physical methods. CL spectra of the samples revealed a defect emission at 2.25 eV in samples prepared by the chemical method, and an emission at 2.5 eV in samples prepared by the physical method. From the thermal treatment studies, it was found that oxygen vacancies are responsible for the 2.5 eV emission. Observed CL quenching in ZnO is explained through the participation of point defects in the energy transfer process from ZnO to Yb3+.

scholarly journals Strain-Induced Form Transition and Crystallization Behavior of the Transparent Polyamide

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1028
Author(s):  
Chenxu Zhou ◽  
Siyuan Dong ◽  
Ping Zhu ◽  
Jiguang Liu ◽  
Dujin Wang ◽  
...  
Keyword(s):  
Crystalline Structure ◽  
Crystallization Behavior ◽  
Heating Process ◽  
Stable Form ◽  
X Ray Diffraction ◽  
Preparation Methods ◽  
Strain Induced Crystallization ◽  
Crystal Transition ◽  
Stretching Deformation ◽  
Induced Crystallization

A transparent polyamide, poly(4,4′-aminocyclohexyl methylene dodecanedicarboxylamide) (PAPACM12), was studied and characterized by in situ wide-angle X-ray diffraction (WAXD) to establish the relationship between its crystallization behavior, crystalline form transition under external fields, and macroscopic properties. During the heating process, cold crystallization occurred and increased, and there was no form transition below the melting point. During the isothermal process, PAPACM12 exhibited the same crystalline structure as that during the heating process. The crystalline structure of PAPACM12 was attributed to α-form crystal, which is the stable form, according to the WAXD diffraction peaks of the conventional AABB-type polyamides. During stretching deformation, the crystal transition from α-form to γ-form and strain-induced crystallization were observed to contribute to the PAPACM12 with higher breaking strength and elongation. This study firstly determine the crystalline structure of transparent polyamides, and then the controlled strain-induced crystallization and transformation are demonstrated to be effective preparation methods for polyamides with high properties.

New Preparation Method and Characterization of Nanosilver

2014 ◽  
Vol 809-810 ◽  
pp. 82-87
Author(s):  
Xin Liu ◽  
Chang Ping Wei ◽  
Li Dan Dong ◽  
Sheng Nan Zhao ◽  
Jing Li ◽  
...  
Keyword(s):  
Chemical Method ◽  
Reduction Method ◽  
Preparation Method ◽  
Low Cost ◽  
Environmental Pollutants ◽  
Physical Method ◽  
Environment Protection ◽  
Preparation Methods ◽  
Microbial Enzyme

There are many kinds of preparation methods of silver nanoparticles ,such as chemical method, physical method plant reduction method and microbial enzyme and so on. The most common method is to use chemical method for reduction. But this method needs to add some chemicals that will produce environmental pollutants. The production consumption will be increased. High quality nanometer silver needing low cost and according with environment protection needs was prepared by using homogeneous precipitation that contains no auxiliary reagent and high temperature pyrolysis in this paper. Experimental results that this method is very effective.

scholarly journals Thermal treatment of aluminous phosphates of the crandallite group and its effect on phosphorus solubility

2007 ◽  
Vol 64 (3) ◽  
pp. 269-274 ◽  
Author(s):  
Eros Artur Bohac Francisco ◽  
Luís Ignácio Prochnow ◽  
Maria Cristina Motta de Toledo ◽  
Viviane Carillo Ferrari ◽  
Sérgio Luís de Jesus
Keyword(s):  
Thermal Treatment ◽  
Crystalline Structure ◽  
Ammonium Citrate ◽  
P Availability ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Agronomic Effectiveness ◽  
X Ray ◽  
Phosphate Deposits ◽  
P Sources

Optimization in the use of phosphate rocks is important and the residues of fertilizer production in the form of crandallite may be suitable for agronomic use after calcination. With the objective of evaluating the effect of thermal treatment of the aluminous phosphates of the crandallite group as related to solubility, crystalline structure and morphology, samples from the mine residues of three Brazilian phosphate deposits (Tapira-MG, Catalão-GO, and Juquiá-SP) were collected, air-dried, and screened to 100 mesh. Sub samples were thermally treated at 300, 500, 700, and 900°C for 2 hours. Treated and untreated materials were analyzed by X-ray diffraction, scanning electronic microscopy, energy dispersive X-ray spectrometry, and for the total and soluble P contents. The treatment of samples: (i) raised P solubility in neutral ammonium citrate solution, (ii) caused the disorganization of the crystalline structure of crandallite at 500°C and above, and (iii) altered their morphology (cracking and rounding). The increase in P solubility of samples after calcination indicates that the agronomic utilization of these marginal P sources may be of interest since plant growth may be favored due to higher P availability. New studies to evaluate these materials in order to determine their agronomic effectiveness must be carried out to establish adequate conditions that favor their use by plants.

scholarly journals Inclusion compound of Fosinopril withβ-cyclodextrin

2009 ◽  
Vol 23 (1) ◽  
pp. 51-58 ◽  
Author(s):  
I. Bratu ◽  
Irina Kacso ◽  
Gh. Borodi ◽  
Daniela E. Constantinescu ◽  
Felicia Dragan
Keyword(s):  
Inclusion Compound ◽  
Diffraction Method ◽  
Differential Scanning Calorimetric ◽  
X Ray Diffraction ◽  
Preparation Methods ◽  
X Ray ◽  
Freeze Dried ◽  
Cyclodextrin Cavity ◽  
Diffraction Patterns ◽  
Co Precipitation

Solid state interactions of bioactive substance (4-cyclohexyl-1-[2-[(2-methyl-1-propanoyloxy-propoxy)-(4-phenylbutyl)phosphoryl]acetyl]-pyrrolidine-2-carboxylic acid, called Fosinopril), withβ-cyclodextrin (β-CD), the so-called inclusion compounds of a bioactive (cardiovascular) drug is obtained by different preparation methods: kneading, co-precipitation and freeze-drying. The so obtained compounds were investigated by FTIR spectroscopy, X-ray diffraction method, and differential scanning calorimetric measurements (DSC) to evidence their formation. X-ray diffraction patterns show that the inclusion compound was obtained for kneaded, co-precipitation and freeze-dried products. The crystalline/amorphous degree for these compounds was also investigated. Molecular modeling (MM+ molecular mechanics) shows the spatial architecture of the inclusion compound in good agreement with FTIR experimental data: the drug is included with the propanoyloxy-propoxy group insideβ-cyclodextrin cavity. These findings may constitute a direct contribution to the molecular encapsulation of Fosinopril intoβ-cyclodextrin, improving Fosinopril stability and bioavailability of the drug, also.

Study of the multiplet nature in shpol'skii effect: Host n-heptane crystalline structure by X-ray diffraction and guest coronene position by ESR

1977 ◽  
Vol 22 (2) ◽  
pp. 207-214 ◽  
Author(s):  
A.M. Merle ◽  
M. Lamotte ◽  
S. Risemberg ◽  
C. Hauw ◽  
J. Gaultier ◽  
...  
Keyword(s):  
Crystalline Structure ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals The Quality of Red Bell Pepper Subjected to Freeze-Drying Preceded by Traditional and Novel Pretreatment

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 226
Author(s):  
Katarzyna Rybak ◽  
Artur Wiktor ◽  
Dorota Witrowa-Rajchert ◽  
Oleksii Parniakov ◽  
Małgorzata Nowacka
Keyword(s):  
Freeze Drying ◽  
Bell Pepper ◽  
Total Phenolic ◽  
Thermal Methods ◽  
Drying Time ◽  
Freeze Dried ◽  
Dehydration Processes ◽  
Vacuum Freezing ◽  
Better Than

It has been demonstrated previously in the literature that utilization of PEF or a combination of a pulsed electric field (PEF) and ultrasounds (US) can facilitate dehydration processes and improve the quality of dried products even better than the application of thermal methods such as blanching. The aim of the study was to evaluate the quality of red bell pepper subjected to freeze-drying preceded by blanching or PEF or US treatment applied in a single and combined mode. Furthermore, the freeze-drying was preceded by shock freezing or vacuum freezing performed inside the freeze-dryer as a result of pressure drop during the first stage of freeze-drying. All of the analyzed technological variants enhanced the drying kinetics when compared to the intact material. Freeze-dried bell pepper subjected to non-thermal pretreatment exhibited higher vitamin C, total phenolic and carotenoids content than blanched material despite the fact that blanching reduced drying time the most compared to all other analyzed methods.

scholarly journals The Importance of Thermal Treatment on Wet-Kneaded Silica–Magnesia Catalyst and Lebedev Ethanol-to-Butadiene Process

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 579
Author(s):  
Sang-Ho Chung ◽  
Adrian Ramirez ◽  
Tuiana Shoinkhorova ◽  
Ildar Mukhambetov ◽  
Edy Abou-Hamad ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Calcination Temperature ◽  
Catalytic Properties ◽  
Catalyst Preparation ◽  
Preparation Methods ◽  
Calcination Temperatures ◽  
Alternative Process ◽  
Magnesium Silicates

The Lebedev process, in which ethanol is catalytically converted into 1,3-butadiene, is an alternative process for the production of this commodity chemical. Silica–magnesia (SiO2–MgO) is a benchmark catalyst for the Lebedev process. Among the different preparation methods, the SiO2–MgO catalysts prepared by wet-kneading typically perform best owing to the surface magnesium silicates formed during wet-kneading. Although the thermal treatment is of pivotal importance as a last step in the catalyst preparation, the effect of the calcination temperature of the wet-kneaded SiO2–MgO on the Lebedev process has not been clarified yet. Here, we prepared and characterized in detail a series of wet-kneaded SiO2–MgO catalysts using varying calcination temperatures. We find that the thermal treatment largely influences the type of magnesium silicates, which have different catalytic properties. Our results suggest that the structurally ill-defined amorphous magnesium silicates and lizardite are responsible for the production of ethylene. Further, we argue that forsterite, which has been conventionally considered detrimental for the formation of ethylene, favors the formation of butadiene, especially when combined with stevensite.

Energy Band Gap Studies of CdS Nanomaterials

2008 ◽  
Vol 3 ◽  
pp. 97-102 ◽  
Author(s):  
Dinu Patidar ◽  
K.S. Rathore ◽  
N.S. Saxena ◽  
Kananbala Sharma ◽  
T.P. Sharma
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Energy Band ◽  
Chemical Method ◽  
Optical Absorption Spectroscopy ◽  
Cds Nanoparticles ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
X Ray ◽  
Simple Chemical

The CdS nanoparticles of different sizes are synthesized by a simple chemical method. Here, CdS nanoparticles are grown through the reaction of solution of different concentration of CdCl2 with H2S. X-ray diffraction pattern confirms nano nature of CdS and has been used to determine the size of particle. Optical absorption spectroscopy is used to measure the energy band gap of these nanomaterials by using Tauc relation. Energy band gap ranging between 3.12 eV to 2.47 eV have been obtained for the samples containing the nanoparticles in the range of 2.3 to 6.0 nm size. A correlation between the band gap and size of the nanoparticles is also established.

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