ZrTiO4 Nanowire Growth Using Membrane-assisted Pechini Route

The high surface-to-volume ratio of nanowires makes them natural competitors as newer device components. In this regard, a current major challenge is to produce quasi-one-dimensional nanostructures composed of well-established oxide-based materials. This article reports the synthesis of ZrTiO4 nanowires on a silicon (100) wafer in a single-step deposition/thermal treatment. The template-directed membrane synthesis strategy was associated with the Pechini route and spin-coating deposition technique. ZrTiO4 nanowires were obtained at 700 °C with diameters in the range of 80-100 nm. FEGSEM images were obtained to investigate ZrTiO4 nanowire formation on the silicon surface and energy dispersive X-ray detection (EDS) and X-ray diffraction (XRD) analyses were performed to confirm the oxide composition and structure. DOI: http://dx.doi.org/10.17807/orbital.v1i1.711 &nbsp

ZrTiO4 Nanowire Growth Using Membrane-assisted Pechini Route

The high surface-to-volume ratio of nanowires makes them natural competitors as newer device components. In this regard, a current major challenge is to produce quasi-one-dimensional nanostructures composed of well-established oxide-based materials. This article reports the synthesis of ZrTiO4 nanowires on a silicon (100) wafer in a single-step deposition/thermal treatment. The template-directed membrane synthesis strategy was associated with the Pechini route and spin-coating deposition technique. ZrTiO4 nanowires were obtained at 700 °C with diameters in the range of 80-100 nm. FEGSEM images were obtained to investigate ZrTiO4 nanowire formation on the silicon surface and energy dispersive X-ray detection (EDS) and X-ray diffraction (XRD) analyses were performed to confirm the oxide composition and structure. DOI: http://dx.doi.org/10.17807/orbital.v1i1.711

Nano‐/microfiber scaffold for tissue engineering: Physical and biological properties

Alginate hydrogel (AH) has intrinsic physical and biological limitations that hinder its broader application in tissue engineering. We hypothesized that the inclusion of nanofibers in the hydrogel and the use of a biotemplate that mimics nature would enhance the translational potential of alginate hydrogels. In this study, we have shown a method to obtain nano‐/microfibers of titanium (nfTD) and hydroxyapatite (nfHY) using cotton as a biotemplate. These fibers were incorporated in the alginate hydrogel and the mechanical characteristics and biological response to these reinforced materials were evaluated. We observed that these nanofibers resembled the structure of natural collagen and did not mediate cell toxicity. The incorporation of nfTD or nfHY to the AH has not increased the viscosity of the hydrogel. Therefore, this is a feasible method to produce a scaffold with improved physical characteristics, while at the same time generating an enhanced environment for cell adhesion and proliferation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3051–3058, 2012.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93772/1/34242_ftp.pd

Preparation, Modification, and Characterization of Alginate Hydrogel with Nano-/Microfibers: A New Perspective for Tissue Engineering

We aimed to develop an alginate hydrogel (AH) modified with nano-/microfibers of titanium dioxide (nfTD) and hydroxyapatite (nfHY) and evaluated its biological and chemical properties. Nano-/microfibers of nfTD and nfHY were combined with AH, and its chemical properties were evaluated by FTIR spectroscopy, X-ray diffraction, energy dispersive X-Ray analysis, and the cytocompatibility by the WST-1 assay. The results demonstrate that the association of nfTD and nfHY nano-/microfibers to AH did not modified the chemical characteristics of the scaffold and that the association was not cytotoxic. In the first 3 h of culture with NIH/3T3 cells nfHY AH scaffolds showed a slight increase in cell viability when compared to AH alone or associated with nfTD. However, an increase in cell viability was observed in 24 h when nfTD was associated with AH scaffold. In conclusion our study demonstrates that the combination of nfHY and nfTD nano-/microfibers in AH scaffold maintains the chemical characteristics of alginate and that this association is cytocompatible. Additionally the combination of nfHY with AH favored cell viability in a short term, and the addition of nfTD increased cell viability in a long term

Active carbon preparation from treads of tire waste for dye removal in waste water

Bandas de rodagem de sucatas de pneus apresentam baixos teores de cargas inorgânicas e grande quantidade de negro de fumo em sua formulação. Neste trabalho, esse material foi tratado com hidróxido de potássio e cloreto de zinco e, em seguida, realizou-se a pirólise a 500 e 700 °C. Foi investigado o desempenho dos produtos na remoção dos corantes azul de metileno e alaranjado de metila em condições ambientais de pH e concentração. Carbonos obtidos com KOH e pirólise a 700 °C apresentam uma melhor capacidade de adsorção. A simulação deste processo permitiu a caracterização dos gases que contribuem para o desenvolvimento da superfície. Os produtos obtidos apresentam estrutura mesoporosa e estreita distribuição no tamanho de partícula. A presença de contaminantes oriundos desses carbonos foi investigada em meio aquoso. A ausência de zinco e enxofre e o excelente desempenho para remoção de corantes fazem esses materiais úteis no tratamento de água.Treads of scrap tires present low contents of inorganic fillers and a large amount of carbon black. In this work, this material was treated with potassium hydroxide and zinc chloride followed by pyrolysis at 500 and 700 °C. The ability to remove methylene blue and methyl orange were investigated under environmental conditions of pH and concentration. Carbons obtained with KOH at 700 °C present superior adsorption capacity. A simulation of this process permitted the characterization of the gases which contributed to surface development. The obtained products present a mesoporous structure and narrow particle size distribution. The presence of contaminants originated from these carbons was investigated in the aqueous media. The absence of zinc and sulfur releasing and the excellent ability to remove organic dye make these materials useful in the treatment of waste water

Compósitos cimentícios reforçados com fibras de eucalipto puras e tratadas com tetraetilortossilicato (TEOS 98%)

O presente trabalho apresenta a obtenção de maior flexibilidade e elasticidade de uma matriz de cimento Portland de alta resistência inicial (CPV) adquirida a partir da adição de fibras de eucalipto puras e tratadas com tetraetilortossilicato TEOS 98%. As fibras utilizadas foram caracterizadas quanto à morfologia, através de microscopia óptica e com o emprego do software Anatomic MIPro, e quanto à absorção de água, para a verificação da eficiência da impregnação do TEOS 98%. Para a obtenção dos compósitos foram formuladas massas de cimento com adição de fibras de eucalipto puras e tratadas nos teores de 2%, 5% e 10% em massa. Os compósitos foram caracterizados quanto a absorção de água, porosidade aparente e módulo de elasticidade (MOE) a partir da resistência à flexão a três pontos. A análise foi comparativa entre os compósitos de cimento-fibras de eucalipto e uma massa pura de cimento Portland de alta resistência inicial. Os resultados mostraram que os maiores valores de reforço foram obtidos no compósito aditivado com 2% de fibra de eucalipto tratada com TEOS 98%, visto que neste se obtiveram os maiores MOE, caracterizando maior controle de fissuras e de absorção de energia após a fratura da matriz de cimento

Compósitos cimentícios reforçados com fibras de eucalipto puras e tratadas com tetraetilortossilicato (TEOS 98%)

O presente trabalho apresenta a obtenção de maior flexibilidade e elasticidade de uma matriz de cimento Portland de alta resistência inicial (CPV) adquirida a partir da adição de fibras de eucalipto puras e tratadas com tetraetilortossilicato TEOS 98%. As fibras utilizadas foram caracterizadas quanto à morfologia, através de microscopia óptica e com o emprego do software Anatomic MIPro, e quanto à absorção de água, para a verificação da eficiência da impregnação do TEOS 98%. Para a obtenção dos compósitos foram formuladas massas de cimento com adição de fibras de eucalipto puras e tratadas nos teores de 2%, 5% e 10% em massa. Os compósitos foram caracterizados quanto a absorção de água, porosidade aparente e módulo de elasticidade (MOE) a partir da resistência à flexão a três pontos. A análise foi comparativa entre os compósitos de cimento-fibras de eucalipto e uma massa pura de cimento Portland de alta resistência inicial. Os resultados mostraram que os maiores valores de reforço foram obtidos no compósito aditivado com 2% de fibra de eucalipto tratada com TEOS 98%, visto que neste se obtiveram os maiores MOE, caracterizando maior controle de fissuras e de absorção de energia após a fratura da matriz de cimento

Active carbon preparation from treads of tire waste for dye removal in waste water

Bandas de rodagem de sucatas de pneus apresentam baixos teores de cargas inorgânicas e grande quantidade de negro de fumo em sua formulação. Neste trabalho, esse material foi tratado com hidróxido de potássio e cloreto de zinco e, em seguida, realizou-se a pirólise a 500 e 700 °C. Foi investigado o desempenho dos produtos na remoção dos corantes azul de metileno e alaranjado de metila em condições ambientais de pH e concentração. Carbonos obtidos com KOH e pirólise a 700 °C apresentam uma melhor capacidade de adsorção. A simulação deste processo permitiu a caracterização dos gases que contribuem para o desenvolvimento da superfície. Os produtos obtidos apresentam estrutura mesoporosa e estreita distribuição no tamanho de partícula. A presença de contaminantes oriundos desses carbonos foi investigada em meio aquoso. A ausência de zinco e enxofre e o excelente desempenho para remoção de corantes fazem esses materiais úteis no tratamento de água.Treads of scrap tires present low contents of inorganic fillers and a large amount of carbon black. In this work, this material was treated with potassium hydroxide and zinc chloride followed by pyrolysis at 500 and 700 °C. The ability to remove methylene blue and methyl orange were investigated under environmental conditions of pH and concentration. Carbons obtained with KOH at 700 °C present superior adsorption capacity. A simulation of this process permitted the characterization of the gases which contributed to surface development. The obtained products present a mesoporous structure and narrow particle size distribution. The presence of contaminants originated from these carbons was investigated in the aqueous media. The absence of zinc and sulfur releasing and the excellent ability to remove organic dye make these materials useful in the treatment of waste water

YbF3/SiO2 Fillers as Radiopacifiers in a Dental Adhesive Resin

The objective of this study was to evaluate the effect of functionalizing a dental adhesive resin with YbF3/SiO2 fillers for use as radiopacifiers. Particles of YbF3/SiO2 were obtained with the high-energy mechanical milling method and characterized by both physical and chemical methods. After characterization, the particles were sieved and silanized prior to being incorporated into an adhesive resin. The stability of the particle suspension was then evaluated. After light activation, the radiopacity, degree of conversion, flexural strength and elastic modulus were determined. The dental adhesive resins with 10 and 15 wt% of filler provided satisfactory radiopacity, while flexural strength and elastic modulus were not affected. The degree of conversion was statistically lower than that of the control (p<0.05). The method used for incorporating the tested ytterbium fluoride/silicon dioxide particles at concentrations of 10 and 15 wt% was shown to be feasible for the development of a radiopaque dental adhesive system

Electrochemical Cathodic Polarization, a Simplified Method That Can Modified and Increase the Biological Activity of Titanium Surfaces: A Systematic Review

<div><p>Background</p><p>The cathodic polarization seems to be an electrochemical method capable of modifying and coat biomolecules on titanium surfaces, improving the surface activity and promoting better biological responses.</p><p>Objective</p><p>The aim of the systematic review is to assess the scientific literature to evaluate the cellular response produced by treatment of titanium surfaces by applying the cathodic polarization technique.</p><p>Data, Sources, and Selection</p><p>The literature search was performed in several databases including PubMed, Web of Science, Scopus, Science Direct, Scielo and EBSCO Host, until June 2016, with no limits used. Eligibility criteria were used and quality assessment was performed following slightly modified ARRIVE and SYRCLE guidelines for cellular studies and animal research.</p><p>Results</p><p>Thirteen studies accomplished the inclusion criteria and were considered in the review. The quality of reporting studies in animal models was low and for the <i>in vitro</i> studies it was high. The <i>in vitro</i> and <i>in vivo</i> results reported that the use of cathodic polarization promoted hydride surfaces, effective deposition, and adhesion of the coated biomolecules. In the experimental groups that used the electrochemical method, cellular viability, proliferation, adhesion, differentiation, or bone growth were better or comparable with the control groups.</p><p>Conclusions</p><p>The use of the cathodic polarization method to modify titanium surfaces seems to be an interesting method that could produce active layers and consequently enhance cellular response, in vitro and in vivo animal model studies.</p></div