scholarly journals Difference in Macroscopic Morphologies of Amylosic Supramolecular Networks Depending on Guest Polymers in Vine-Twining Polymerization

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1277 ◽  
Author(s):  
Saya Orio ◽  
Takuya Shoji ◽  
Kazuya Yamamoto ◽  
Jun-ichi Kadokawa
Keyword(s):  
Inclusion Complexes ◽  
Host Molecule ◽  
X Ray Diffraction ◽  
Grafted Polymers ◽  
Electron Microscopic ◽  
X Ray ◽  
Natural Polysaccharide ◽  
Scanning Electron Microscopic ◽  
The Difference ◽  
Supramolecular Networks

Amylose, a natural polysaccharide, acts as a host molecule to form supramolecular inclusion complexes in its enzymatically formation process, that is, phosphorylase-catalyzed enzymatic polymerization using the α-d-glucose 1-phosphate monomer and the maltooligosaccharide primer, in the presence of appropriate guest polymers (vine-twining polymerization). Furthermore, in the vine-twining polymerization using maltooligosaccharide primer-grafted polymers, such as maltoheptaose (G7)-grafted poly(γ-glutamic acid) (PGA), in the presence of poly(ε-caprolactone) (PCL), the enzymatically elongated amylose graft chains have formed inclusion complexes with PCL among the PGA main-chains to construct supramolecular networks. Either hydrogelation or aggregation as a macroscopic morphology from the products was observed in accordance with PCL/primer feed ratios. In this study, we evaluated macroscopic morphologies from such amylosic supramolecular networks with different guest polymers in the vine-twining polymerization using G7-grafted PGA in the presence of polytetrahydrofuran (PTHF), PCL, and poly(l-lactide) (PLLA). Consequently, we found that the reaction mixture using PTHF totally turned into a hydrogel form, whereas the products using PCL and PLLA were aggregated in the reaction mixtures. The produced networks were characterized by powder X-ray diffraction and scanning electron microscopic measurements. The difference in the macroscopic morphologies was reasonably explained by stabilities of the complexes depending on the guest polymers.

scholarly journals Preparation of Reswellable Amorphous Porous Celluloses through Hydrogelation from Ionic Liquid Solutions

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3249 ◽  
Author(s):  
Satoshi Idenoue ◽  
Yoshitaka Oga ◽  
Daichi Hashimoto ◽  
Kazuya Yamamoto ◽  
Jun-ichi Kadokawa
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquid ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Liquid Solutions ◽  
Scanning Electron Microscopic ◽  
Porous Morphology ◽  
Scanning Electron

In this study, we have performed the preparation of reswellable amorphous porous celluloses through regeneration from hydrogels. The cellulose hydrogels were first prepared from solutions with an ionic liquid, 1-butyl-3-methylimidazolium chloride (BMIMCl), in different concentrations. Lyophilization of the hydrogels efficiently produced the regenerated celluloses. The powder X-ray diffraction and scanning electron microscopic measurements of the products suggest an amorphous structure and porous morphology, respectively. Furthermore, the pore sizes of the regenerated celluloses, or in turn, the network sizes of cellulose chains in the hydrogels, were dependent on the concentrations of the initially prepared solutions with BMIMCl, which also affected the tensile mechanical properties. It was suggested that the dissolution states of the cellulose chains in the solutions were different, in accordance with the concentrations, which representatively dominated the pore and network sizes of the above materials. When the porous celluloses were immersed in water, reswelling was observed to regenerate the hydrogels.

Inclusion Complexes between Starch and Vanillin

2019 ◽  
Vol 811 ◽  
pp. 34-39
Author(s):  
Rachmawati Rachmawati ◽  
Ida Ayu Dwitasari
Keyword(s):  
Inclusion Complexes ◽  
Physical Mixture ◽  
Host Molecule ◽  
X Ray Diffraction ◽  
Starch Solution ◽  
X Ray ◽  
Diffraction Peaks ◽  
The Stability ◽  
Single Helix ◽  
Scanning Electron

Vanillin is an additive widely used in foods and beverages. This research focused on formation of inclusion complexes to improve the stability of vanillin. The amylose in starch can act as a host molecule by forming a single helix known as V-amylose which has a hydrophobic channel. In this research, the starch was suspended in water (2.8% (w/v)) and was sonicated for 30 minutes. The mixture was subsequently heated at 180 °C to dissolve starch. Vanillin dissolved in ethanol was then mixed with the starch solution at around 85 °C. The concentration of vanillin was varied at 10%, 30% and 50% (w/w, based on the weight of starch). The resulting inclusion complexes were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), and Scanning Electron Microscope (SEM). FTIR characterizations were conducted on starch, vanillin, physical mixture of starch-vanillin, and the inclusion complexes. The results showed there were differences on some vibration peaks between the physical mixture of starch-vanillin and the inclusion complex. The XRD results depicted different patterns of the diffraction peaks for the inclusion complexes compared to native starch and vanillin which showed that the starch-vanillin complexes were successfully formed.

scholarly journals Influence of the type of electrolyte on the morphological and crystallographic characteristics of lead powder particles

2013 ◽  
Vol 78 (9) ◽  
pp. 1387-1395 ◽  
Author(s):  
Nebojsa Nikolic ◽  
Vesna Maksimovic ◽  
Goran Brankovic ◽  
Predrag Zivkovic ◽  
Miomir Pavlovic
Keyword(s):  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Lead Powder ◽  
Scanning Electron Microscopic ◽  
Crystallographic Characteristics ◽  
Powder Particles ◽  
Primary Type ◽  
Secondary Type ◽  
Scanning Electron

Lead electrodeposition processes from the basic (nitrate) and complex (acetate) electrolytes were mutually compared by the scanning electron microscopic and the X-ray diffraction analysis of the produced powder particles. The shape of dendritic particles strongly depended on the type of electrolyte. The dendrites composed of stalk and weakly developed primary branches (the primary type) were predominantly formed from the basic electrolyte. The ramified dendrites composed of stalk and of both primary and secondary branches (the secondary type) were mainly formed from the complex electrolyte. In the both type of powder particles Pb crystallites were predominantly oriented in the (111) plane. Formation of powder particles of the different shape with the strong (111) preferred orientation was discussed and explained by the consideration of the general characteristics of the growth of a crystal in the electrocrystallization processes.

Characterization on Aggregating Structure of Aloe Extract Crosslinked Cotton Fabric

2011 ◽  
Vol 311-313 ◽  
pp. 1132-1135 ◽  
Author(s):  
Yun Hui Xu ◽  
Li Chen
Keyword(s):  
Citric Acid ◽  
Cotton Fabric ◽  
Cotton Textile ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Scanning Electron Microscopic ◽  
Ft Ir ◽  
Textile Products

For exploiting the multifunctional ecological cotton textile products and developing the green modified technology for cotton fabrics, a novel cotton fabric with aloe extract crosslinking was prepared using citric acid as a crosslink agent under the pad-dry-cure procedure. Scanning electron microscopic photographs showed that the modification with aloe extract occurred on the surface of cotton fabric. FT-IR spectra of the modified fabric illuminated that aloe extract crosslinked with cotton fabric through the bridge linkage of citric acid after a series of reaction. The wide angle X-ray diffraction analysis indicated that the crystallinity of aloe extract modified cotton fabric slightly decreased. Furthermore, the changes in the aggregating structure and crystallinity were also reflected in the mechanical property studies of these modified fabrics. After treatment by aloe extract, the breaking strength and elongation of cotton fabric decreased. However, the moisture regain of the modified cotton fabric increased. The results obtained are useful in explaining structure-property correlations with respect to the aggregating structure and crystallinity, and suggest valuable information in planning applications for the aloe extract modified cotton textile products.

Epitaxial Growth of α-Fe2O3 Thin Films on c-Plane Sapphire Substrate by Hydrothermal Method

2011 ◽  
Vol 702-703 ◽  
pp. 999-1002 ◽  
Author(s):  
Song Li ◽  
Gao Wu Qin ◽  
Liang Zuo
Keyword(s):  
Thin Films ◽  
Gas Sensors ◽  
Sapphire Substrate ◽  
Electron Microscopic Observation ◽  
Interface Energy ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Scanning Electron Microscopic ◽  
Hydrolysis Of

Thin films of hematite find extensive applications in photoelectrochemistry, photocatalysis, and gas sensors. c-axis oriented hematite films have been directly grown on c-plane sapphire substrate using chemical method via hydrolysis of ferric cations. X-ray diffraction (XRD) reveals that the crystalline phases of the films and corresponding sediment produced in the solution were α-Fe2O3 and pure β-FeOOH, demonstrating the promotion of nucleation of hematite on sapphire substrate as a result of lowered interface energy. Phi-scan results indicate that the hematite films are grown with (0001) planes parallel to c-plane of Al2O3. Scanning electron microscopic observation shows that the hematite films are composed of pyramid-shaped nanocrystals with smooth surface facets.

Fabrication of SnS2 Flower Like Nanoflake Assemblies Through Thermal Evaporation

2007 ◽  
Vol 7 (12) ◽  
pp. 4540-4545 ◽  
Author(s):  
Subhajit Biswas ◽  
Soumitra Kar ◽  
Tandra Ghoshal ◽  
Subhadra Chaudhuri
Keyword(s):  
Thermal Evaporation ◽  
Growth Direction ◽  
Vapor Concentration ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Transmission Electron ◽  
Scanning Electron Microscopic ◽  
The Individual

Uniform as well as flower like patterns of SnS2 nanoflakes were produced by a thermal evaporation process. Interpenetrating phenomenon was observed between the individual nanoflakes during the course of their lateral growth. The interpenetrating growth and controlled vapor concentration as well as the substrate temperature leads to the formation of flower like assemblies of SnS2 nanoflakes. Morphology and growth mechanism of the nanostructures were studied by scanning electron microscopic observations at different stages of the nanoflake growth. The produced nanoflakes were characterized by X-ray diffraction, scanning and transmission electron microscopy, and Raman spectroscopic measurements. SnS2 nanoflakes were perfectly single crystalline and growth direction of the nanoflakes was along the {101}-lattice plane.

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