Preparation and Characterization of PVA-Collagen Composite Fibers

2011 ◽  
Vol 236-238 ◽  
pp. 83-86 ◽  
Author(s):  
Xian Hui Sun

The collagen was blended with polyvinyl alcohol (PVA) with the maximum maintenance of the natural structure as precondition. The apparent viscosity and rheology property of PVA-collagen blended solution were studied. the mechanical properties of the blend membrane formed from PVA-collagen blended solution were also determined. The PVA-collagen blended solution was wet spinned with the sodium sulfate as coagulant to prepare PVA-collagen composite fibers. SEM analysis and X-ray diffraction analysis of the PVA-collagen composite fibers were studied. The results indicated that, blended with PVA, the spinning property and mechanical properties of collagen were improved. The figure of the aim fiber transect structure was similar as the kidney, and it had a uniform size. The crystallization degree of the fiber was 55.7%, and it was increased with the increase of the hot extending temperature and the extending ratio.

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1563
Author(s):  
Sofia Marquez-Bravo ◽  
Ingo Doench ◽  
Pamela Molina ◽  
Flor Estefany Bentley ◽  
Arnaud Kamdem Tamo ◽  
...  

Extremely high mechanical performance spun bionanocomposite fibers of chitosan (CHI), and cellulose nanofibers (CNFs) were successfully achieved by gel spinning of CHI aqueous viscous formulations filled with CNFs. The microstructural characterization of the fibers by X-ray diffraction revealed the crystallization of the CHI polymer chains into anhydrous chitosan allomorph. The spinning process combining acidic–basic–neutralization–stretching–drying steps allowed obtaining CHI/CNF composite fibers of high crystallinity, with enhanced effect at incorporating the CNFs. Chitosan crystallization seems to be promoted by the presence of cellulose nanofibers, serving as nucleation sites for the growing of CHI crystals. Moreover, the preferential orientation of both CNFs and CHI crystals along the spun fiber direction was revealed in the two-dimensional X-ray diffraction patterns. By increasing the CNF amount up to the optimum concentration of 0.4 wt % in the viscous CHI/CNF collodion, Young’s modulus of the spun fibers significantly increased up to 8 GPa. Similarly, the stress at break and the yield stress drastically increased from 115 to 163 MPa, and from 67 to 119 MPa, respectively, by adding only 0.4 wt % of CNFs into a collodion solution containing 4 wt % of chitosan. The toughness of the CHI-based fibers thereby increased from 5 to 9 MJ.m−3. For higher CNFs contents like 0.5 wt %, the high mechanical performance of the CHI/CNF composite fibers was still observed, but with a slight worsening of the mechanical parameters, which may be related to a minor disruption of the CHI matrix hydrogel network constituting the collodion and gel fiber, as precursor state for the dry fiber formation. Finally, the rheological behavior observed for the different CHI/CNF viscous collodions and the obtained structural, thermal and mechanical properties results revealed an optimum matrix/filler compatibility and interface when adding 0.4 wt % of nanofibrillated cellulose (CNF) into 4 wt % CHI formulations, yielding functional bionanocomposite fibers of outstanding mechanical properties.


2020 ◽  
Author(s):  
Sahar. Mokhtari ◽  
Anthony.W. Wren

AbstractThis study addresses issues with currently used bone adhesives, by producing novel glass based skeletal adhesives through modification of the base glass composition to include copper (Cu) and by characterizing each glass with respect to structural changes. Bioactive glasses have found applications in fields such as orthopedics and dentistry, where they have been utilized for the restoration of bone and teeth. The present work outlines the formation of flexible organic-inorganic polyacrylic acid (PAA) – glass hybrids, commercial forms are known as glass ionomer cements (GICs). Initial stages of this research will involve characterization of the Cu-glasses, significant to evaluate the properties of the resulting adhesives. Scanning electron microscopy (SEM) of annealed Cu glasses indicates the presence of partial crystallization in the glass. The structural analysis of the glass using Raman suggests the formation of CuO nanocrystals on the surface. X-ray diffraction (XRD) pattern and X-ray photoelectron spectroscopy (XPS) further confirmed the formation of crystalline CuO phases on the surface of the annealed Cu-glass. The setting reaction was studied using Fourier transform infrared spectroscopy (ATR-FTIR). The mechanical properties of the Cu containing adhesives exhibited gel viscoelastic behavior and enhanced mechanical properties when compared to the control composition. Compression data indicated the Cu glass adhesives were efficient at energy dissipation due to the reversible interactions between CuO nano particles and PAA polymer chains.


2011 ◽  
Vol 55-57 ◽  
pp. 1436-1440 ◽  
Author(s):  
Xiao Hua Zhao ◽  
Guang Hui Min ◽  
Jing Xu ◽  
Jie Lin

Lanthanum hexaboride (LaB6) films were deposited on Si (111) substrates by magnetron sputtering method. The characterization of the films was investigated by means of atom force microscopy (AFM), X-ray diffraction (XRD), four-point probe electrical resistance measurement, scratch tester and nano-indentation tester. Influence of argon pressure on physical properties, such as crystallization degree, conductivity and mechanical properties was studied. All the films were smooth and dense. The film crystallites showed a preferential orientation of (100) plane, but the films which were deposited at 2.0 Pa exhibited amorphous structures. LaB6 films which were deposited below 1.5 Pa had excellent conductivity. The bonding strength of the films which were deposited at 1.0 Pa was higher than the others due to the formation of the nano-sized crystals. The hardness and elastic modulus were investigated in connection with the crystalline of LaB6 films. As a result, the films which were deposited at 1.0 Pa had a maximal value of hardness (16.782 Gpa) and elasticity modulus (193.895 Gpa). In a word, the LaB6 films which were deposited at 1.0 Pa have a higher degree of crystalline and more excellent physical properties in comparison with the others. The obtained results will be used synthesizing LaB6 films for applications in low-temperature thermoelectric devices.


2011 ◽  
Vol 412 ◽  
pp. 61-64
Author(s):  
Xiao Bo Wu ◽  
Da Zhi Sun ◽  
Dan Yu Jiang ◽  
Hai Fang Xu ◽  
De Xin Huang ◽  
...  

3Y-TZP powder has been successfully synthesized by gel solid-state method. The structural phases of powder particles were analyzed by X-ray diffraction and the morphology was analyzed by scanning electron microscopy. The average size of grains was 230 nm. The sintering behavior, mechanical properties and microstructure of 3Y-TZP ceramics sintered by this powder were investigated. The experiment results showed that the mechanical properties of ceramics were excellent.


2012 ◽  
Vol 724 ◽  
pp. 249-254 ◽  
Author(s):  
Bum Rae Cho ◽  
Ji Hoon Chae ◽  
Bo Lang Kim ◽  
Jong Bong Kang

Sintered ZTA(zirconia toughened alumina) which has good mechanical properties at a low temperature was produced by milling and mixing with Al2O3 and ZrO2(3Y-TZP). In order to examine the effect of sintering aids on the mechanical properties of ZTA, fracture toughness and hardness of the produced ZTA were observed in accordance with change of the added quantity of ZrO2 Scanning electron microscopy and X-ray diffraction technique were applied to observe microstructural change and phase transformation during the process. Experimental results showed that the addition of sintering aids in ZTA at a low temperature induced densification and adding SiO2 and talc lowered sintering temperature and promoted crystallization process of the compound. The mechanical strength of ZTA added ZrO2 showed higher mechanical strength and SEM analysis revealed that Al2O3 and ZrO2 during the sintering process restrained the grain growth each other. Especially, the 92% Al2O3 added sintering aids showed more than 98% of the theoretical density and more than 1500 Hv of hardness value at a low temperature of 1400. It was also showed that the fracture toughness is gradually increasing first and decreasing later in accordance with the quantity of ZrO2.


2010 ◽  
Vol 13 (1-2) ◽  
pp. 17
Author(s):  
K.V.R. Murthy ◽  
K. Suresh ◽  
B. Nageswara Rao ◽  
B. Walter Ratna Kumar ◽  
Ch. Atchyutha Rao ◽  
...  

<p>The present paper reports the Photoluminescence (PL) of the Sr<sub>2</sub>CeO<sub>4</sub> phosphor, singly doped with Erbium rare-earth ion with different concentrations (0.01, 0.1, 0.2, 0.5 and 1%).The phosphor samples were synthesized using the standard solid state reaction technique. The effect of Er dopant on the structural, morphological, and Photoluminescent properties of the samples are studied with X-ray diffraction (XRD), PL and SEM analysis. The PL emission of undoped Sr<sub>2</sub>CeO<sub>4</sub> phosphor was observed at 470 nm with high intensity followed by the primary Er emissions with good intensity at 525, 530, 549, 557 and 565 nm.</p>


Abstract: The photocatalytic composite Fe doped AC/TiO2 has been prepared by sol-gel method. The prepared Fe doped AC/TiO2 composite were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD).The SEM analysis showed that Fe and TiO2 were attached to the Activated Carbon surfaces. The X-Ray Diffraction data showed that Fe doped AC/TiO2 composite mostly contained anatase phase.


2018 ◽  
Vol 51 (2) ◽  
pp. 175-190 ◽  
Author(s):  
F Oulmou ◽  
A Benhamida ◽  
A Dorigato ◽  
A Sola ◽  
M Messori ◽  
...  

The preparation and thermo-mechanical characterization of composites based on polyamide 11 (PA11) filled with various amounts of both expandable and expanded graphites are presented. Investigation conducted using X-ray diffraction (XRD), scanning electron microscopy and surface area analyses indicated how graphite expanded under the selected processing conditions. The XRD analysis on PA11/graphite composites revealed no change in the crystal form of the PA11, while the presence of diffraction peaks associated to the graphite-stacked lamellae can be still detected. All the investigated composites showed an improvement of the thermal stability and mechanical properties (elastic and storage moduli).


2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Y. Ngueumdjo ◽  
V. H. Njuikom Djoumbi ◽  
V. Y. Katte ◽  
F. Ngapgue ◽  
A. S. L. Wouatong

AbstractThis study reports on the physical, mechanical, mineralogical and geochemical analysis carried out on four lateritic hardpan specimens from quarries in the Bamendjou area in the Western Region of Cameroon using common prescribed procedures. The results indicate that values of the bulk density, specific gravity, total and open porosities are very variable from one specimen to another. Meanwhile, the value of the compressive strengths of both the dry and immersed specimens were also very variable from one specimen to another, with the F2 and F1 specimens having higher values than the A1 and A2 specimens. All the specimens immersed in water recorded lower compressive strengths than the dry specimens. The flexural strengths also varied from one sample to another, with the F2 specimen having the highest resistance. The X-ray diffraction patterns reveal that the major peaks were assigned to gibbsite, goethite, and hematite, while the minor peaks were assigned to kaolinite and anatase. The mineralogy and geochemistry influenced the physical and mechanical properties, with the iron rich specimens having higher values in both the physical and mechanical properties than the alumina rich specimens. The results of the compressive strengths obtained were higher than (1–4) MPa obtained in Burkina Faso and India where they have been using latertic blocks for construction. Thus the hardpans of Bamendjou can also be exploited for building purposes conveniently.


Author(s):  
Priscila Richa ◽  
Roberto Costa Lima ◽  
Ana Paula Santiago de Falco ◽  
Ana Paula da Silva ◽  
Elvia Leal ◽  
...  

Radar-absorbing materials (RAMs) have been used in military applications for several decades to reduce radar detection of vessels and aircrafts. In the present work, the performance of Ni0.35Zn0.35Cu0.3Fe2O4 ferrite as a RAM is investigated. The ferrite was firstly synthesized by combustion reaction and then calcinated at 1200 °C for 1 h. Composites were prepared with 80:20, 70:30 and 60:40 concentrations in weight of ferrite:polychloroprene. The X-ray diffraction (XRD) analysis showed a single phase ferrite formation and the scanning electron microscopy (SEM) analysis of the composites showed a good dispersion of the ferrite in the polychloroprene matrix. The electromagnetic (EM) characterization of the composites revealed that the EM attenuation is mainly attributed to magnetic losses observed in the material. The 80:20 composite achieved the best performance and presented a reflectivity of -26.7 dB at 10.2 GHz.


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