Preparation and characterization of hydroxybutyl chitosan

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Bin Zhu ◽  
Changzheng Wei ◽  
Chunlin Hou ◽  
Qisheng Gu ◽  
Dajun Chen
Keyword(s):  
Chemical Modification ◽  
Sol Gel ◽  
Chitosan Solution ◽  
Water Soluble ◽  
Full Potential ◽  
Thermosensitive Polymer ◽  
New Type ◽  
Gel Phase ◽  
Further Development

AbstractThe insolubility in neutral condition is a major problem that confronts the further development of processing and uses of chitosan. Special emphasis has been put on the chemical modification of chitosan to explore its full potential. Studies on these methods are also encouraging and many kinds of water-soluble and alcohol-soluble derivatives have appeared. In this article, hydroxybutyl chitosan, a new type of thermosensitive polymer, was prepared through the chemical modification of 1,2-epoxybutane. Hydroxybutyl chitosan solution underwent sol/gel phase transition at a certain temperature lower than 20 °C, however, at high temperature, hydroxybutyl chitosan can form hydrogel with a certain mechanical strength. Hydroxybutyl chitosan could be an ideal themosensitive material applied in drug delivery system, tissue engineering and other biomedical fields.

Synthesis and Characterization of Li(Li0.05Ni0.6Fe0.1Mn0.25)O2 Cathode Material for Lithim Ion Batteries

2018 ◽  
Vol 21 (1) ◽  
pp. 051-056
Author(s):  
A. Nichelson ◽  
S. Thanikaikarasan ◽  
K. Karuppasamy ◽  
S. Karthickprabhu ◽  
T. Mahalingam ◽  
...  
Keyword(s):  
Cathode Material ◽  
Sol Gel ◽  
Lithium Ion ◽  
Chelating Agent ◽  
X Ray Diffraction ◽  
Morphological Studies ◽  
New Type ◽  
Ft Ir ◽  
Ir And Raman

A new type of lithium enriched cathode material Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 was synthesized by sol-gel method with citric acid as a chelating agent. The structural and morphological studies were systematically investigated through X-ray diffraction, SEM with EDS, FT-IR and Raman analyses. The crystallite size of the Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 cathode material was found to be 45 nm thereby leads to the feasible movement of lithium ion all through the material. FT-IR spectroscopy was used to confirm the metal-oxygen interaction in the prepared cathode material. The electrical properties of the Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 cathode material were studied by impedance and dielectric spectral analyzes. Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 showed a maximum ionic conductivity of 10-6 S/cm at ambient temperature.

Physicochemical Characterization of Novel Chitosan-Soy Protein/ TEOS Porous Hybrids for Tissue Engineering Applications

2006 ◽  
Vol 514-516 ◽  
pp. 1000-1004 ◽  
Author(s):  
S.S. Silva ◽  
J. Miguel Oliveira ◽  
João F. Mano ◽  
Rui L. Reis
Keyword(s):  
Soy Protein ◽  
Sol Gel ◽  
Physicochemical Characterization ◽  
Compression Tests ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Sol Gel Process ◽  
New Type ◽  
Reflectance Ftir

In this paper we report a new type of cross-linked porous structure based on a chitosansoy protein blend system developed by means of combining a sol-gel process with the freeze-drying technique. The final structure was investigated by Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), contact angle measurements and the morphology by scanning electron microscopy (SEM). The water uptake capability and the weight loss were measured up to 14 days and their mechanical properties were assessed with compression tests. Results showed that the addition of tetraethyl orthosilicate (TEOS) to the chitosan-soy protein blend system provide specific interactions at the interface between the two polymers allowing to tailor the size and distribution as well as the degradation rate of the hybrids. Finally, TEOS incorporation induces an increase of the surface energy that influences the final physicochemical properties of the materials.

scholarly journals Real-time characterization of hydrogel viscoelastic properties and sol-gel phase transitions using cantilever sensors

2020 ◽  
Vol 64 (4) ◽  
pp. 837-850
Author(s):  
Alexander P. Haring ◽  
Manjot Singh ◽  
Miharu Koh ◽  
Ellen Cesewski ◽  
David A. Dillard ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Real Time ◽  
Viscoelastic Properties ◽  
Sol Gel ◽  
Cantilever Sensors ◽  
Gel Phase

Characterization of Chemical Impurities in Glutaraldehyde

1975 ◽  
Vol 33 ◽  
pp. 620-621
Author(s):  
B. J. Grenon ◽  
A. J. Tousimis
Keyword(s):  
Glutaric Acid ◽  
Spectroscopic Analysis ◽  
Aldol Condensation ◽  
Condensation Product ◽  
Amorphous Solid ◽  
Water Soluble ◽  
Impurity Component ◽  
Chemical Impurities ◽  
Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

Porous Gel Coatings Obtained by Phase Separation in ORMOSIL System

2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai
Keyword(s):  
Phase Separation ◽  
Reaction Time ◽  
Volume Fraction ◽  
Sol Gel ◽  
Reaction Times ◽  
Dip Coating ◽  
Coating Solution ◽  
Coating Method ◽  
Gel Phase ◽  
Dip Coating Method

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.

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