scholarly journals Development, Fabrication, and Characterization of Composite Polycaprolactone Membranes Reinforced with TiO2 Nanoparticles

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1955 ◽  
Author(s):  
Karina del Ángel-Sánchez ◽  
César I. Borbolla-Torres ◽  
Luis M. Palacios-Pineda ◽  
Nicolás A. Ulloa-Castillo ◽  
Alex Elías-Zúñiga

This paper focuses on developing, fabricating, and characterizing composite polycaprolactone (PCL) membranes reinforced with titanium dioxide nanoparticles (NPs) elaborated by using two solvents; acetic acid and a mixture of chloroform and N,N-dimethylformamide (DMF). The resulting physical, chemical, and mechanical properties of the composite materials are studied by using experimental characterization techniques such as scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) analysis, contact angle (CA), uniaxial and biaxial tensile tests, and surface roughness measurements. Experimental results show that the composite material synthesized by sol-gel and chloroform-DMF has a better performance than the one obtained by using acetic acid as a solvent.

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2650
Author(s):  
Thibault Lemaire ◽  
Erica Gea Rodi ◽  
Valérie Langlois ◽  
Estelle Renard ◽  
Vittorio Sansalone

In recent years the interest in the realization of green wood plastic composites (GWPC) materials has increased due to the necessity of reducing the proliferation of synthetic plastics. In this work, we study a specific class of GWPCs from its synthesis to the characterization of its mechanical properties. These properties are related to the underlying microstructure using both experimental and modeling approaches. Different contents of Miscanthus giganteus fibers, at 5, 10, 20, 30 weight percent’s, were thus combined to a microbial matrix, namely poly (3-hydroxybutyrate)-co-poly(3-hydroxyvalerate) (PHBHV). The samples were manufactured by extrusion and injection molding processing. The obtained samples were then characterized by cyclic-tensile tests, pycnometer testing, differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and microscopy. The possible effect of the fabrication process on the fibers size is also checked. In parallel, the measured properties of the biocomposite were also estimated using a Mori–Tanaka approach to derive the effective behavior of the composite. As expected, the addition of reinforcement to the polymer matrix results in composites with higher Young moduli on the one hand, and lower failure strains and tensile strengths on the other hand (tensile modulus was increased by 100% and tensile strength decreased by 23% when reinforced with 30 wt % of Miscanthus fibers).


2011 ◽  
Vol 1326 ◽  
Author(s):  
Rene Fabian Cienfuegos ◽  
Leonardo Chávez Guerrero ◽  
Sugeheidy Carranza ◽  
Laurie Jouanin ◽  
Guillaume Marie ◽  
...  

ABSTRACTThe goal in this study was to synthesize a lanthanum - nickel phase (Ruddlesden-Popper phases) La4Ni3O10. This material was prepared using a polymeric route. An easy synthesis method is presented in order to obtain an economical cathode material, which can be used in Solid Oxide Fuel Cells (SOFC). The polymeric precursors were prepared following the Castillo method. The originality of this work was to optimize the ratio HMTA/ metallic salts from 1 to 6. The obtained powders were characterized by thermal analysis; Differential Scanning Calorimetry (DSC Q10 Instrument TA), Thermogravimetric Analysis (TGA - Q50 Instrument TA-) and X-ray diffractometer (Bruker, D8 Advance diffractometer), in order to determine the crystallized phase. Experiments 5 and 6 did not present coagulation but after few days, solution 5 was transformed into a gel. Gels 2 to 5 were heated in order to obtain a solid material. These powders are characterized by thermogravimetric and thermo-differential methods. The powders obtained at 800, 900 and 1000°C were analyzed by X-ray diffraction and it was found that the temperature to get to the La4Ni3O10 phase was 1000ºC.


2014 ◽  
Vol 6 ◽  
pp. 945819 ◽  
Author(s):  
Maria Aparecida Larosa ◽  
André Luiz Jardini ◽  
Cecília Amélia de Carvalho Zavaglia ◽  
Paulo Kharmandayan ◽  
Davi Reis Calderoni ◽  
...  

Custom-built implants manufacture has always presented difficulties which result in high cost and complex fabrication, mainly due to patients’ anatomical differences. The solution has been to produce prostheses with different sizes and use the one that best suits each patient. Additive manufacturing technology, incorporated into the medical field in the late 80's, has made it possible to obtain solid biomodels facilitating surgical procedures and reducing risks. Furthermore, this technology has been used to produce implants especially designed for a particular patient, with sizes, shapes, and mechanical properties optimized, for different areas of medicine such as craniomaxillofacial surgery. In this work, the microstructural and mechanical properties of Ti6Al4V samples produced by direct metal laser sintering (DMLS) are studied. The microstructural and mechanical characterizations have been made by optical and scanning electron microscopy, X-ray diffraction, and microhardness and tensile tests. Samples produced by DMLS have a microstructure constituted by hexagonal α′ martensite with acicular morphology. An average microhardness of 370 HV was obtained and the tensile tests showed ultimate strength of 1172 MPa, yield strength of 957 MPa, and elongation at rupture of 11%.


2009 ◽  
Vol 67 ◽  
pp. 227-232 ◽  
Author(s):  
Gurpreet Singh ◽  
Amrish Panwar ◽  
Anjan Sil ◽  
Sudipto Ghosh

Nanocrystalline LiMn2O4 powder was synthesized by sol-gel method using citric acid as a chelating agent. The powders were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Differential scanning calorimetry (DSC), Differential thermal analysis (DTA), Impedance spectroscopy (IS) and Electrochemical measurements. The powder particles having slight agglomeration characteristics were found to have prismatic morphology and a wider size distribution from 50 nm to 200 nm, which provides good packing density of the material. The electrical conductivity of the powder at room temperature is in the order of ~10-5 S/cm. The structural stability of LiMn2O4 cubic spinel over the temperature range of battery operation was assessed. Electrochemical performance of the material shows a discharge capacity of ~130 mAh/gm.


2017 ◽  
Vol 899 ◽  
pp. 212-215
Author(s):  
Paula de Freitas Rosa ◽  
Ana Clara Matias Alves ◽  
Mônica Lopes Aguiar ◽  
André Bernardo

Currently nanoparticles are being widely used because they have large surface area and pronounced effect relative to the properties of the material. Silver and Titanium Dioxide nanoparticles, for example, have pronounced biocidal effects, since they can inactivate certain enzymes and alter the DNA synthesis of some microorganisms. It is expected that a composite of the nanoparticles of the two metals can further increase the biocide power. This way, the study of the synthesis and characterization of nanocomposites becomes highly relevant. The aim of this work was to synthesize Ag-TiO2 nanocomposites and to characterize them in order to contribute to the understanding of the preparation of nanocomposite materials. In this study, we used a sol-gel method, which makes use of a reduction reaction using sodium citrate as the reducing agent, and titanium butoxide, acetic acid and silver nitrate as starting material. After being synthesized, the nanocomposite was analyzed with the techniques of Scanning Electron Microscopy coupled to energy dispersive X-ray detector (SEM / EDS) and X-ray Diffraction.


2010 ◽  
Vol 148-149 ◽  
pp. 1062-1066 ◽  
Author(s):  
Ren Bo Yang ◽  
Wei Guo Fu ◽  
Xiang Yun Deng ◽  
Zhong Wen Tan ◽  
Yan Jie Zhang ◽  
...  

The (Ba0.88Ca0.12)( Zr0.12Ti0.88)O3 powders and piezoelectric ceramics were prepared by sol-gel process. The reaction process was analyzed with the help of thermo gravimetric and differential scanning calorimetry. X-ray diffraction characterized results showed that the structure of the (Ba0.88Ca0.12)( Zr0.12Ti0.88)O3 powders was perovskite structure and the particle size was approximately 37nm. Piezoelectric measurements revealed that Curie temperature and the maximum piezoelectric coefficient d33 is 95°C and 215pm/V, respectively.


2007 ◽  
Vol 352 ◽  
pp. 129-132
Author(s):  
Qing Hong Zhang ◽  
Lian Gao

In this paper, we reported the preparation of nanocrystalline Ta3N5 particles by nitridation of Ta2O5 nanoparticles using NH3 as reactant gas. It was found that nanocrystalline Ta2O5 was converted into Ta3N5 completely at 700°C within 5.0 h, which was much lower than the temperature 850°C for the complete nitridation of micron-sized Ta2O5 powder. The resulting nitride was characterized by X-ray diffraction analysis (XRD) and field emission scanning electron microscopy (FE-SEM). The nitrogen contents in the prepared Ta3N5 powders were quantitatively determined with CHN elemental analyzer and thermogravimetry and differential scanning calorimetry (TG-DSC). The color of nanocrystalline Ta3N5 is in fresh red while the one of micrometer-sized Ta3N5 is in dark red.


Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.


Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 261
Author(s):  
Adolfo Bucio ◽  
Rosario Moreno-Tovar ◽  
Lauro Bucio ◽  
Jessica Espinosa-Dávila ◽  
Francisco Anguebes-Franceschi

A study on the physical and mechanical properties of beeswax (BW), candelilla wax (CW), paraffin wax (PW) and blends was carried out with the aim to evaluate their usefulness as coatings for cheeses. Waxes were analyzed by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), differential scanning calorimetry (DSC), permeability, viscosity, flexural and tensile tests and scanning electron microscopy. Cheeses were coated with the waxes and stored for 5 weeks at 30 °C. Measured parameters were weight, moisture, occurrence and degree of fractures, and dimensional changes. The crystal phases identified by XRD for the three waxes allowed them to determine the length of alkanes and the nonlinear compounds in crystallizable forms in waxes. FTIR spectra showed absorption bands between 1800 and 800 cm−1 related to carbonyls in BW and CW. In DSC, the onset of melting temperature was 45.5 °C for BW, and >54 °C for CW and PW. Cheeses coated with BW did not show cracks after storage. Cheeses coated with CW and PW showed microcraks, and lost weight, moisture and shrunk. In the flexural and tensile tests, BW was ductile; CW and PW were brittle. BW blends with CW or PW displays a semi ductile behavior. Cheeses coated with BW blends lost less than 5% weight during storage. The best waxes were BW and the blends.


2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.


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