scholarly journals Construction of Cellulose/Carboxymethyl Chitosan Hydrogels for Potential Wound Dressing Application

2021 ◽  
Author(s):  
Yi Guo ◽  
Chuanyin Zhao ◽  
Chao Yan ◽  
Li Cui
Keyword(s):  
Wound Dressing ◽  
Thermo Gravimetric Analysis ◽  
Pore Wall ◽  
Carboxymethyl Chitosan ◽  
Cross Linking ◽  
Cellulose Content ◽  
Gravimetric Analysis ◽  
Composite Hydrogels ◽  
Equilibrium Swelling Ratio ◽  
Chitosan Hydrogels

Abstract In this study, novel cellulose/carboxymethyl chitosan (CMCS) composite hydrogels were constructed by blending cellulose and CMCS in LiOH/urea aqueous solutions, and then cross-linking with epichlorohydrin. The structure and morphology of the composite hydrogels were characterized by Fourier transform infrared spectroscopy (FT-IR), wide-angle X-ray diffraction (WXRD), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results revealed that the chemical cross-linking reaction between cellulose and CMCS occurred in the hydrogel, and CMCS contributed to the enhancement of pore size, whereas cellulose as a strong backbone in the hydrogel to support the pore wall. The mechanical strength of the composite hydrogels increased with the cellulose content, while the equilibrium swelling ratio and antibacterial activity increased with the CMCS content. The composite hydrogels had no cytotoxicity towards L929 cells, suggesting good biocompatibility. All these results indicate that cellulose/CMCS composite hydrogels can be effectively used as a material in wound dressing.

Attainment and characterization of carboxymethyl chitosan hydrogels by enzymatic cross-linking

2019 ◽  
Vol 138 (5) ◽  
pp. 3635-3643
Author(s):  
Andreia de Araújo Morandim-Giannetti ◽  
Patrick de Oliveira Wecchi ◽  
Paula de Araújo Silvério ◽  
Regina Carlstron ◽  
Patrícia Alessandra Bersanetti
Keyword(s):  
Carboxymethyl Chitosan ◽  
Cross Linking ◽  
Chitosan Hydrogels

Preparation of N-Methylpolyborosilazane -Derived Bulk Si-B-N-C Ceramics by Warm-Pressing and Pressureless Pyrolysis

2012 ◽  
Vol 557-559 ◽  
pp. 1148-1151
Author(s):  
Zhen Quan Liu ◽  
Jing Zhang ◽  
Xian Xing Qiu ◽  
Yu Qing Peng ◽  
Ke Qing Han ◽  
...  
Keyword(s):  
High Temperature ◽  
Ceramic Body ◽  
Thermo Gravimetric Analysis ◽  
Amorphous Structure ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Green Body ◽  
Thermo Gravimetric ◽  
Temperature Resistance ◽  
Bulk Ceramic

Additive-free bulk Si-B-N-C ceramics were prepared by pyrolysis of preceramic precursor (PBS-Me), which mainly involves cross linking, warm-pressing and pyrolysis. The density of crack-free bulk ceramic attains 1.94 g/cm3 when Calcined at 1300 °C. The shaped workpieces exhibit amorphous structure even be pyrolysised at 1400°C in N2, and there are some pores existing in the green body derived from warm-pressing and the resulting Si-B-N-C ceramic body, and these pores allow the gaseous byproducts be expeled from bodies. The pyrolyzed samples were studied by high temperature thermo gravimetric analysis, it shows that the Si-B-N-C body had an excellent high temperature resistance.

scholarly journals Effect of Radiation-Induced Cross-Linking on Thermal Aging Properties of Ethylene-Tetrafluoroethylene for Aircraft Cable Materials

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 257
Author(s):  
Xiaodong Zhang ◽  
Fei Chen ◽  
Zhimin Su ◽  
Taiping Xie
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Thermo Gravimetric Analysis ◽  
Thermal Characteristics ◽  
Volume Resistivity ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Aging Properties ◽  
Radiation Induced ◽  
Ethylene Tetrafluoroethylene

The effects of electron beam irradiation on ethylene-tetrafluoroethylene copolymer (ETFE) were studied. Samples were irradiated in air at room temperature by a universal electron beam accelerator for various doses. The effect of irradiation on samples and the cross-linked ETFE after aging were investigated with respect to thermal characteristics, crystallinity, mechanical properties, and volume resistivity using thermo-gravimetric analysis (TGA), differential scanning calorimeter (DSC), universal mechanical tester, and high resistance meter. TGA showed that thermal stability of irradiated ETFE is considerably lower than that of unirradiated ETFE. DSC indicates that crystallinity is altered greatly by cross-link. The analysis of mechanical properties, fracture surface morphology, visco-elastic properties and volume resistivity certify radiation-induced cross-linking is vital to aging properties.

Delonix Regia Fruit Fibers: A New Potential Source of Cellulosic Fibers

2020 ◽  
Vol 979 ◽  
pp. 185-196
Author(s):  
Kalpit P. Kaurase ◽  
Dalbir Singh
Keyword(s):  
Chemical Constituents ◽  
Thermo Gravimetric Analysis ◽  
Cellulose Content ◽  
Gravimetric Analysis ◽  
Plant Fibers ◽  
Delonix Regia ◽  
Cellulosic Fibers ◽  
Lignocellulosic Fibers ◽  
Chemically Treated ◽  
Ft Ir

Lignocellulosic fibers have attracted the attention of researchers, academicians and industries in recent years. These fibers have several advantages as compared to conventionally used fibers such as availability in abundance in nature as it can be extracted from almost every plants, biodegradability, environmental friendliness, high specific strength, etc. Cellulose content of fiber depends on the chemical constituents of the source plant from which it is extracted hence it becomes necessary to understand the constituents of lignocellulosic fibers before its application. In this paper, a new source (Delonix Regia Fruit) of cellulosic fibers has been evaluated and chemical constituents of Delonix Regia fruit fiber has been compared with several lignocellulosic plant fibers. Also, Delonix Regia Fruit fibers are presented as a new source of cellulose and Chemical methods are used for extraction of cellulose from it. Chemically Treated and untreated fibers are characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and Thermo Gravimetric Analysis (TGA) to understand the effect of chemical treatment, properties of the cellulose yield. From the results compositional analysis it can be seen that Delonix Regia fruit fibers have 66.9% cellulose content which is very high as compared to most of the popular sources which makes it suitable and cost effective to extract cellulose from it and can be used in biocomposites and bionanocomposites. Analysis of FT-IR spectra of untreated and chemically treated Delonix Regia Fruit Fibers revealed the removal of hemi-cellulose and lignin by chemical treatments followed. TGA-DTG results proved that highly purified yield of cellulose is successfully extracted by the chemical route followed.

Synthesis of Smart Mesoporous Materials

2003 ◽  
Vol 775 ◽  
Author(s):  
G.V.Rama Rao ◽  
Qiang Fu ◽  
Linnea K. Ista ◽  
Huifang Xu ◽  
S. Balamurugan ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Mesoporous Materials ◽  
Fluorescent Dyes ◽  
Thermo Gravimetric Analysis ◽  
Molecular Transport ◽  
Solute Diffusion ◽  
Gravimetric Analysis ◽  
Stimuli Responsive ◽  
Porous Network ◽  
Hybrid Mesoporous Materials

AbstractThis study details development of hybrid mesoporous materials in which molecular transport through mesopores can be precisely controlled and reversibly modulated. Mesoporous silica materials formed by surfactant templating were modified by surface initiated atom transfer radical polymerization of poly(N-isopropyl acrylamide) (PNIPAAm) a stimuli responsive polymer (SRP) within the porous network. Thermo gravimetric analysis and FTIR spectroscopy were used to confirm the presence of PNIPAAm on the silica surface. Nitrogen porosimetry, transmission electron microscopy and X-ray diffraction analyses confirmed that polymerization occurred uniformly within the porous network. Uptake and release of fluorescent dyes from the particles was monitored by spectrofluorimetry and scanning laser confocal microscopy. Results suggest that the presence of PNIPAAm, a SRP, in the porous network can be used to modulate the transport of aqueous solutes. At low temperature, (e.g., room temperature) the PNIPAAm is hydrated and extended and inhibits transport of analytes; at higher temperatures (e.g., 50°C) it is hydrophobic and is collapsed within the pore network, thus allowing solute diffusion into or out of the mesoporous silica. The transition form hydrophilic to hydrophobic state on polymer grafted mesoporous membranes was determined by contact angle measurements. This work has implications for the development of materials for the selective control of transport of molecular solutes in a variety of applications.

Coordination Compounds of Some 3d-Transition Metal Ions with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)- thiosemicarbazide

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu
Keyword(s):  
Coordination Compounds ◽  
Magnetic Moments ◽  
Thermo Gravimetric Analysis ◽  
Electronic Spectroscopy ◽  
Transition Metal Ions ◽  
Synthesis And Characterization ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
New Compounds

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.

Collagen And Carbon-Ferrous Nanoparticles Used As A Green Energy Composite Material For Energy Storage Devices

2020 ◽  
Vol 13 ◽  
Author(s):  
Inbasekaran S. ◽  
G. Thiyagarajan ◽  
Ramesh C. Panda ◽  
S. Sankar
Keyword(s):  
Composite Material ◽  
Thermo Gravimetric Analysis ◽  
Value Added ◽  
Green Energy ◽  
Nano Particles ◽  
Hydroxyl Group ◽  
Gravimetric Analysis ◽  
Circuit Testing ◽  
Battery Cell ◽  
Dc Voltage

Background:: Chrome shavings, a bioactive material, are generated from tannery as waste material. These chrome shaving can be used for the preparation of many value-added products. Objective:: One such attempt is made to use these chrome shaving wastes as a composite bio-battery to produce DC voltage, an alternate green energy source and cleaner technology. Methods:: Chrome shavings are hydrolyzed to make collagen paste and mixed with the ferrous nanoparticles of Moringa oleifera leaves and Carbon nanoparticles of Onion peels to form electrolyte paste as base. Then, the electrolyte base was added to the aluminum paste and conducting gel, and mixed well to form composite material for bio-battery. Results:: The composite material of bio-battery has been characterized using Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). Series and parallel circuit testing were done using Copper and Zinc electrodes or Carbon and Zinc electrodes as the battery terminals in the electrolyte paste. The surface area of these electrodes needs standardization from bench to pilot scale. The power generated, for an AA battery size, using a single bio-battery cell has produced a DC voltage of 1.5 V; current of 900 mA. Circuit testing on 1 ml of 80 well-cells connected in series has produced DC output of 18 V and 1100 mA whereas 48 V and 1500 mA were obtained from a series-parallel connection. Conclusion:: The glass transition temperature (Tg) of electrolyte of the bio-battery at 53°C indicates that, at this temperature, all the substances present in the bio-battery are well spread and contributing consistently to the electrolyte activity where Fe-C-Nano-Particles were able to form strong chemical bonds on the flanking hydroxyl group sites of the Collagen leading to reduced mobility of polymers and increase Tg. The results instigate promising trends for commercial exploitation of this composite for bio-battery production.

In-situ stabilization of silver nanoparticles in polymer hydrogels for enhanced catalytic reduction of macro and micro pollutants

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Luqman Ali Shah ◽  
Rida Javed ◽  
Mohammad Siddiq ◽  
Iram BiBi ◽  
Ishrat Jamil ◽  
...  
Keyword(s):  
Catalytic Reduction ◽  
Thermo Gravimetric Analysis ◽  
Activation Parameters ◽  
Reduction Reaction ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
In Situ Stabilization ◽  
Hybrid Hydrogels ◽  
Kinetics Of

AbstractThe in-situ stabilization of Ag nanoparticles is carried out by the use of reducing agent and synthesized three different types of hydrogen (anionic, cationic, and neutral) template. The morphology, constitution and thermal stability of the synthesized pure and Ag-entrapped hybrid hydrogels were efficiently confirmed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The prepared hybrid hydrogels were used in the decolorization of methylene blue (MB) and azo dyes congo red (CR), methyl Orange (MO), and reduction of 4-nitrophenol (4-NP) and nitrobenzene (NB) by an electron donor NaBH4. The kinetics of the reduction reaction was also assessed to determine the activation parameters. The hybrid hydrogen catalysts were recovered by filtration and used continuously up to six times with 98% conversion of pollutants without substantial loss in catalytic activity. It was observed that these types of hydrogel systems can be used for the conversion of pollutants from waste water into useful products.

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