The preparation method and composition of the viscose as factors in its physico-chemical properties in the ripening process

1971 ◽  
Vol 3 (6) ◽  
pp. 642-645
Author(s):  
V. G. Kulichikhin ◽  
B. L. Biber ◽  
E. B. Kostikova ◽  
D. N. Arkhangelskii ◽  
M. A. Ginzberg ◽  
...  
Keyword(s):  
Preparation Method ◽  
Chemical Properties ◽  
Ripening Process ◽  
Physico Chemical

Chitosan-Nanocellulose Composites for Regenerative Medicine Applications

2020 ◽  
Vol 27 (28) ◽  
pp. 4584-4592 ◽  
Author(s):  
Avik Khan ◽  
Baobin Wang ◽  
Yonghao Ni
Keyword(s):  
Regenerative Medicine ◽  
Preparation Method ◽  
Chemical Properties ◽  
Biological Properties ◽  
Next Generation ◽  
Structure Property ◽  
Physico Chemical ◽  
Structure Property Relationship ◽  
Attractive Candidate ◽  
Fundamental Understanding

Regenerative medicine represents an emerging multidisciplinary field that brings together engineering methods and complexity of life sciences into a unified fundamental understanding of structure-property relationship in micro/nano environment to develop the next generation of scaffolds and hydrogels to restore or improve tissue functions. Chitosan has several unique physico-chemical properties that make it a highly desirable polysaccharide for various applications such as, biomedical, food, nutraceutical, agriculture, packaging, coating, etc. However, the utilization of chitosan in regenerative medicine is often limited due to its inadequate mechanical, barrier and thermal properties. Cellulosic nanomaterials (CNs), owing to their exceptional mechanical strength, ease of chemical modification, biocompatibility and favorable interaction with chitosan, represent an attractive candidate for the fabrication of chitosan/ CNs scaffolds and hydrogels. The unique mechanical and biological properties of the chitosan/CNs bio-nanocomposite make them a material of choice for the development of next generation bio-scaffolds and hydrogels for regenerative medicine applications. In this review, we have summarized the preparation method, mechanical properties, morphology, cytotoxicity/ biocompatibility of chitosan/CNs nanocomposites for regenerative medicine applications, which comprises tissue engineering and wound dressing applications.

scholarly journals The Influence of the Preparation Method on the Physico-Chemical Properties and Catalytic Activities of Ce-Modified LDH Structures Used as Catalysts in Condensation Reactions

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6191
Author(s):  
Alexandra-Elisabeta Stamate ◽  
Rodica Zăvoianu ◽  
Octavian Dumitru Pavel ◽  
Ruxandra Birjega ◽  
Andreea Matei ◽  
...  
Keyword(s):  
Preparation Method ◽  
Mixed Oxides ◽  
Condensation Reaction ◽  
Chemical Properties ◽  
Precipitation Method ◽  
Synthesis Methods ◽  
Molar Ratios ◽  
Base Catalysts ◽  
Physico Chemical ◽  
Co Precipitation

Mechanical activation and mechanochemical reactions are the subjects of mechanochemistry, a special branch of chemistry studied intensively since the 19th century. Herein, we comparably describe two synthesis methods used to obtain the following layered double hydroxide doped with cerium, Mg3Al0.75Ce0.25(OH)8(CO3)0.5·2H2O: the mechanochemical route and the co-precipitation method, respectively. The influence of the preparation method on the physico-chemical properties as determined by multiple techniques such as XRD, SEM, EDS, XPS, DRIFT, RAMAN, DR-UV-VIS, basicity, acidity, real/bulk densities, and BET measurements was also analyzed. The obtained samples, abbreviated HTCe-PP (prepared by co-precipitation) and HTCe-MC (prepared by mechanochemical method), and their corresponding mixed oxides, Ce-PP (resulting from HTCe-PP) and Ce-MC (resulting from HTCe-MC), were used as base catalysts in the self-condensation reaction of cyclohexanone and two Claisen–Schmidt condensations, which involve the reaction between an aromatic aldehyde and a ketone, at different molar ratios to synthesize compounds with significant biologic activity from the flavonoid family, namely chalcone (1,3-diphenyl-2-propen-1-one) and flavone (2-phenyl-4H-1benzoxiran-4-one). The mechanochemical route was shown to have indisputable advantages over the co-precipitation method for both the catalytic activity of the solids and the costs.

scholarly journals PCL/POSS Nanocomposites: Effect of POSS Derivative and Preparation Method on Morphology and Properties

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 33 ◽  
Author(s):  
Mónica Cobos ◽  
Johnny R. Ramos ◽  
Dailyn J. Guzmán ◽  
M. Dolores Fernández ◽  
M. Jesús Fernández
Keyword(s):  
Preparation Method ◽  
Chemical Properties ◽  
Surface Hydrophobicity ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Melt Compounding ◽  
Physico Chemical ◽  
Amino Derivatives ◽  
The One ◽  
Crystalline Aggregates

The incorporation of polyhedral oligomeric silsesquioxanes (POSS) molecules as nanoparticles into polymers can provide improved physico-chemical properties. The enhancement depends on the extent of dispersion of the nanofiller, which is determined by the compatibility with the polymer that is by the POSS type, and the processing method. In this study, poly(ε-caprolactone)/POSS derivatives nanocomposites (PCL/POSS) were obtained via solution-casting and melt compounding. Two amino-derivatives containing different alkyl substituents, and ditelechelic POSS-containing hybrid PCL masterbatch were used as nanofillers. The effect of preparation method, POSS content and type on the morphology, thermal, mechanical, and surface properties of nanocomposites were studied. Morphological analysis evidenced the formation of POSS crystalline aggregates, self-assembled POSS molecules of submicrometer size dispersed in the polymer matrix. The best dispersion was achieved using the ditelechelic POSS-containing hybrid PCL masterbatch, and comparing the two amino-POSS derivatives, the one with longer alkyl chain of substituents exhibited better degree of dispersion independent of preparation method. DSC analysis showed the role of POSS derivatives as nucleating agents for PCL. The incorporation of POSS derivatives into the PCL matrix improved thermal stability. The preparation method, POSS type and content had influence on mechanical properties of nanocomposites. POSS nanoparticles enhanced the surface hydrophobicity of PCL.

scholarly journals New Preparation Method and Its Physico-chemical Properties of Foxtail Millet (Setaria italica Beauv.) Starch

2007 ◽  
Vol 54 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Yoriko Tezuka ◽  
Kazuko Hirao ◽  
Tomoko Hamanishi ◽  
Naoko Matsunaga ◽  
Keiji Kainuma ◽  
...  
Keyword(s):  
Preparation Method ◽  
Foxtail Millet ◽  
Chemical Properties ◽  
Setaria Italica ◽  
Physico Chemical

scholarly journals Physico-chemical characterization of 'Zarco HS' yellow bell pepper for different ripeness stages

2007 ◽  
Vol 64 (1) ◽  
pp. 19-22 ◽  
Author(s):  
Silvia Antoniali ◽  
Paulo Ademar Martins Leal ◽  
Ana Maria de Magalhães ◽  
Rogério Tsuyoshi Fuziki ◽  
Juliana Sanches
Keyword(s):  
Chemical Properties ◽  
Chemical Characterization ◽  
Titratable Acidity ◽  
Bell Pepper ◽  
Soluble Solids ◽  
Ripening Process ◽  
Physico Chemical ◽  
Bell Peppers

The bell pepper presents alterations in its composition and its properties with the process of senescence during ripening. These composition and textual factors are part of the quality of the fruit and therefore of the selection. This permits the correct knowledge of the factors necessary for post-harvest measures, so that they can be adequately applied. The aim of this study is to analyze the 'Zarco HS' yellow pepper at various levels of ripeness taking into account its physico-chemical properties (titratable acidity, pH, total soluble solids, water content, and ascorbic acid), in order to understand this behavior during the ripening process. Bell peppers were separated based on their yellow percentage, which varied from 0% to 100%, and for each percentage five fruits were chosen as replicates. They were compared to 0%, 25%, 50%, 75% and 100% levels of ripening, due to the difficulty of the methodology in identifying the smaller differences between coloring. The 'Zarco HS' yellow bell pepper presents greater levels of soluble solids and lower levels of malic acid as the percentage of external yellow coloring increases. The yellow bell peppers, especially when totally yellow, represent an important source of vitamin C.

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

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