Bioglass® Coatings on Superelastic NiTi Wires by Electrophoretic Deposition (EPD)

2006 ◽  
Vol 314 ◽  
pp. 219-224 ◽  
Author(s):  
Aldo Roberto Boccaccini ◽  
E.J. Minay ◽  
D. Krause

45S5 Bioglass® coatings have been produced on superelastic nickel-titanium wires using electrophoretic deposition (EPD). Aqueous suspensions of Bioglass® particles (< 5 &m mean particle size) were used. EPD led to the formation of thick and uniform coatings covering the wires very homogeneously, without the development of any microcracks during the drying stage. Best results were achieved with suspensions containing 20 wt% Bioglass®, an applied voltage of 5 V, and a deposition time of 5 min. Samples sintered for 1 hour at temperatures > 800 °C exhibited diffusion of nickel and titanium into the Bioglass® coating. Scanning electron microscopy (SEM) was used to analyse the microstructure of the Bioglass® coatings in terms of level of uniformity, densification, and to discover the possible presence of microcracks, as well as to gain information about the thickness of the coating produced on the different substrates. The results demonstrate that the EPD technique is a very convenient method to produce uniform Bioglass® coatings on wires for biomedical applications.

2018 ◽  
Vol 3 (1) ◽  
pp. 12 ◽  
Author(s):  
Zaimahwati Zaimahwati ◽  
Yuniati Yuniati ◽  
Ramzi Jalal ◽  
Syahman Zhafiri ◽  
Yuli Yetri

<p>Pada penelitian ini telah dilakukan isolasi dan karakterisasi bentonit alam menjadi nanopartikel montmorillonit. Bentonit alam yang digunakan diambil dari desa Blangdalam, Kecamatan Nisam Kabupaten Aceh Utara.  Proses isolasi meliputi proses pelarutan dengan aquades, ultrasonic dan proses sedimentasi. Untuk mengetahui karakterisasi montmorillonit dilakukan uji FT-IR, X-RD dan uji morfologi permukaan dengan Scanning Electron Microscopy (SEM). Partikel size analyzer untuk menganalisis dan menentukan ukuran nanopartikel dari isolasi bentonit alam. Dari hasil penelitian didapat ukuran nanopartikel montmorillonit hasil isolasi dari bentonit alam diperoleh berdiameter rata-rata 82,15 nm.</p><p><em>In this research we have isolated and characterized natural bentonite into montmorillonite nanoparticles. Natural bentonite used was taken from Blangdalam village, Nisam sub-district, North Aceh district. The isolation process includes dissolving process with aquades, ultrasonic and sedimentation processes.  The characterization of montmorillonite, FT-IR, X-RD and surface morphology test by Scanning Electron Microscopy (SEM). Particle size analyzer to analyze and determine the size of nanoparticles from natural bentonite insulation. From the research results obtained the size of montmorillonite nanoparticles isolated from natural bentonite obtained an average diameter of 82.15 nm.</em></p>


2021 ◽  
Vol 22 (11) ◽  
pp. 5730
Author(s):  
Jomarien García-Couce ◽  
Marioly Vernhes ◽  
Nancy Bada ◽  
Lissette Agüero ◽  
Oscar Valdés ◽  
...  

Hydrogels obtained from combining different polymers are an interesting strategy for developing controlled release system platforms and tissue engineering scaffolds. In this study, the applicability of sodium alginate-g-(QCL-co-HEMA) hydrogels for these biomedical applications was evaluated. Hydrogels were synthesized by free-radical polymerization using a different concentration of the components. The hydrogels were characterized by Fourier transform-infrared spectroscopy, scanning electron microscopy, and a swelling degree. Betamethasone release as well as the in vitro cytocompatibility with chondrocytes and fibroblast cells were also evaluated. Scanning electron microscopy confirmed the porous surface morphology of the hydrogels in all cases. The swelling percent was determined at a different pH and was observed to be pH-sensitive. The controlled release behavior of betamethasone from the matrices was investigated in PBS media (pH = 7.4) and the drug was released in a controlled manner for up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay showed that almost all hydrogels are cytocompatibles and an increase of proliferation in both cell types after one week of incubation was observed by the Live/Dead® assay. These results demonstrate that these hydrogels are attractive materials for pharmaceutical and biomedical applications due to their characteristics, their release kinetics, and biocompatibility.


2007 ◽  
Vol 561-565 ◽  
pp. 2163-2166 ◽  
Author(s):  
H.Z. Abdullah ◽  
Charles C. Sorrell

Rutile nano-powders were suspended in a solution of acetylacetone and iodine. The suspensions were electrophoretically deposited on titanium foil at a voltage range of 5-30 V over times of 5-120 s. The dried tapes then were sintered at 800°C for 2 h in flowing argon. Both the green and fired tapes were examined by field emission scanning electron microscopy, optical microscopy, X-ray diffraction, and Raman microspectroscopy. The thickness of the films depended on the voltage and the time of deposition. The sintered microstructures depended significantly on the thickness of the film, which was a function the proximity to the Ti/TiO2 interface. The interface is critical to the microstructure because it acts as the source of defect formation, which enhances sintering, grain growth, and grain facetting.


2013 ◽  
Vol 19 (2) ◽  
pp. 276-284 ◽  
Author(s):  
George Vander Voort ◽  
Beatriz Suárez-Peña ◽  
Juan Asensio-Lozano

AbstractThe present study investigates the effect of the solidification strategy for AA 6063 alloy on the surface appearance of anodized extrusions. The microstructure of the samples was analyzed using both light optical microscopy and scanning electron microscopy. Results show that if heavy segregation occurs from rapid solidification, coarse Mg2Si particles form, thus reducing the potential for precipitation strengthening by the finer β-Mg2Si developed in the solid state. Differentially-strained regions formed during hot extrusion induce differences in particle size for magnesium silicide (Mg2Si) precipitates. Anodizing generates surface roughness due to Mg2Si particle dissolution and AlFeSi decohesion, which is related to both particle size and deformation. During anodizing, an oxide layer forms on the surface of the extruded products, which can lead to streak formation, usually a subject of rejection due to unacceptable heterogeneous reflectivity.


2017 ◽  
Vol 6 (1) ◽  
pp. 31 ◽  
Author(s):  
Dessy Kurniasari ◽  
Sri Atun

Tujuan penelitian ini adalah untuk membuat dan mengetahui karakteristik nanopartikel dari ekstrak etanol temu kunci (Boesenbergia pandurata) dan rasio optimal variasi konsentrasi kitosan dan NaTPP dalam pembuatan nanopartikel temu kunci.            Pembuatan ekstrak temu kunci (Boesenbergia pandurata) menggunakan metode maserasi menggunakan etanol teknis 96% dilanjutkan evaporasi hingga terbentuk ekstrak kental temu kunci. Koloid nanopartikel dibuat dengan mencampurkan ekstrak temu kunci dalam etanol p.a, akuades, larutan kitosan dalam asam asetat glasial, dan larutan NaTPP. Ada 9 variasi komposisi antara larutan kitosan dan  NaTPP yakni rasio (5:1); (10:1); (15:1); (20:1); (3,33:1); (8:1); (9:1); (11:1); dan (12:1). Padatan dalam koloid nanopartikel dipisahkan dengan cara sentrifugasi. Endapan yang didapatkan disimpan dalam freezer. Koloid nanopartikel yang terbentuk dikarakterisasi menggunakan Particle Size Analyzer (PSA) dan Zeta Sizeruntuk mengetahui ukuran partikel dan nilai zeta potensial. Padatan yang didapatkan dari proses sentrifugasi selanjutnya dikarakterisasi menggunakan Scanning Electron Microscopy (SEM) untuk mengetahui kondisi morfologi padatan tersebut. Karakterisasi dengan KLT pada padatan yang didapatkan bertujuan untuk mengetahui kesamaan kandungan senyawa antara ekstrak etanol temu kunci dan ekstrak etanol temu kunci dalam sediaan berukuran nano.            Koloid nanopartikel yang telah dibuat berwarna kuning dan setelah di sentrifugasi terbentuk padatan berwarna kuning kecokelatan. Karakterisasi menggunakan PSA menunjukkan ukuran partikel pada rentang 389-877 nm sebanyak 98,1% pada rasio konsentrasi kitosan dan NaTPP = (8:1). Nilai rerata zeta potensial adalah 41,87 mV. Hasil foto SEM menunjukkan morfologi partikel yang memiliki permukaan yang tidak rata. Rf keenam sampel menunjukkan hasil bahwa senyawa yang terkandung dalam ekstrak etanol temu kunci maupun ekstrak etanol temu kunci dalam sediaan nanopartikel adalah sama. Kata Kunci : kitosan, NaTPP, ekstrak etanol temu kunci, KLT, SEM, PSA, zeta sizer


2013 ◽  
Vol 750-752 ◽  
pp. 336-339
Author(s):  
Fa Chao Wu ◽  
Teng Fei Shen

In this work, CaCO3 nanoparticles have been synthesized via heat-treatment of a new precursor. Effect of calcinations temperature on particle size has been investigated. The products were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). nanoCaCO3 was modified using chloroform as solvent and fatty acid as modifier atroom temperature. The advantage of this modification is that it can be proceed at room temperature and it can reduce energy consumption.


2012 ◽  
Vol 507 ◽  
pp. 127-133 ◽  
Author(s):  
Sigrid Seuss ◽  
Tayyab Subhani ◽  
Min Yi Kang ◽  
Kenji Okudaira ◽  
Isaac E. Aguilar Ventura ◽  
...  

Electrophoretic deposition (EPD) has been successfully used to deposit composite coatings composed of polyetheretherketone (PEEK) and titanium dioxide (TiO2) nanoparticles on 316L stainless steel substrates. The suspensions of TiO2 nanoparticles and PEEK microparticles for EPD were prepared in ethanol. PEEK-TiO2 composite coatings were optimized using suspensions containing 6wt% PEEK-TiO2 in ethanol with a 3:1 ratio of PEEK to TiO2 in weight and by applying a potential difference of 30 V for 1 minute. A heat-treatment process of the optimized PEEK-TiO2 composite coatings was performed at 335°C for 30 minutes with a heating rate of 10°Cminto densify the deposits. The EPD coatings were microstructurally evaluated by scanning electron microscopy (SEM). It was demonstrated that EPD is a convenient and rapid method to fabricate PEEK/TiO2 coatings on stainless steel which are interesting for biomedical applications.


2012 ◽  
Vol 557-559 ◽  
pp. 1197-1200
Author(s):  
Jung Ting Tsai ◽  
Cheng Yu Han ◽  
Shung Tian Lin

The goal of this study was to investigate the sintering mechanism of Si powder, with the particle size of Si, sintering temperature, and sintering environment as the variables. The use of a crucible, by controlling the vapor atmosphere at certain temperatures, coarsened the silicon powder. Experiment of data show that by avoiding the vapor pressure of crucible a sintering at 1380°C causes the silicon powder easily to sinter to high density, without the use of any doping addition. Therefore it is to our advantage to discover the microstructure phenomenon of silicon powder and reveal its nature. The crystalline structure of the heat-treated samples was studied with Scanning electron microscopy (SEM) to explain the resultant of contamination that causes the densification.


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