Microstructural and Mechanical Characterization of Colloidal Processed WC/(W5Vol%Ni) via Spark Plasma Sintering.

This study investigates the sintering behaviour and properties of WC-based composites in which WC was mixed with W5vol%Ni in concentrations of 10vol% and 20vol%. Colloidal processing in water and spark plasma sintering were employed to disperse the WC particles and facilitate sintering. The addition of W5vol%Ni improved the sintering process, as evident from a lower onset temperature of shrinkage determined through dilatometric studies.

Operational Variables on the Processing of Porous Titanium Bodies by Gelation of Slurries with an Expansive Porogen.

Colloidal processing techniques, based on the suspension of powders in a liquid, are very versatile techniques to fabricate porous structures. They can provide customized pores, shapes and surfaces through the control of operational parameters, being the base of the alternative additive manufacture processes. In this work disperse and stable titanium aqueous slurries has been formulated in order to process porous materials by the incorporation of methylcellulose (MC) as a gelation agent and ammonium bicarbonate as an expansive porogen.

Controlled SrR Delivery by the Incorporation of Mg Particles on Biodegradable PLA-Based Composites.

Among several ions playing a vital role in the body, Sr and Mg are involved in the mechanism of bone formation, making them especially useful for bone tissue engineering applications. Recently, polylactic acid (PLA)/Mg composites have emerged as a promising family of biomaterials due to their inherent biocompatibility and biodegradability properties. In these composites, polymer and bio-metal have a synergetic effect-while the PLA inhibits the Mg fast reactivity, Mg provides bioactivity to the inert polymer buffering the medium pH during degradation.

Capability of core-sheath polyvinyl alcohol-polycaprolactone emulsion electrospun nanofibrous scaffolds in releasing strontium ranelate for bone regeneration.

Core-sheath nanofibrous scaffolds from polyvinyl alcohol (PVA)-strontium ranelate (SrR)-Polycaprolactone (PCL) were prepared by water in oil electrospinning method. Thus, PCL (the oil phase) was used as the shell part and a mixture of PVA and SrR (the water phase) was inserted in the core. The amounts of SrR was varied from 0 to 15 wt.

Effect of SrR delivery in the biomarkers of bone regeneration during the in vitro degradation of HNT/GN coatings prepared by EPD.

Among strontium-based drugs, the Strontium ranelate (SrR) is a divalent strontium salt of ranelic acid which has an overall effect over the bone microarchitecture improvement. However, some findings reveal that the SrR affects in an opposite manner to the cell proliferation and osteoblastic differentiation, based on its concentration. Consequently, its release should be controlled.

Effect of highly dispersed yttria addition on thermal stability of hydroxyapatite.

The capability of the colloidal method to produce yttria (Y(2)O(3)) dispersed hydroxyapatite (HA) has been investigated as an alternative method to the conventional method of mechanical mixing and sintering for developing HA-based materials that could exhibit controllable and enhanced functional properties. A water based colloidal route to produce HA materials with highly dispersed Y(2)O(3) has been applied, and the effect of 10 wt.% Y(2)O(3) addition to HA investigated by thermal analysis, X-ray diffraction and Fourier transform infrared spectroscopy.

Functionalizing Ti-surfaces through the EPD of hydroxyapatite/nanoY2O3.

Ceramic materials for skeletal repair and reconstruction are expanding to a number of different applications. Present research is addressing new compositions and performances to promote osseo-integration through metal coatings. Nanotechnology plays a key role in this research because nanostructures can be introduced into implants to functionalize them and/or to enhance their properties, such as the thermal or mechanical response.

Effect of reaction conditions on size and morphology of ultrasonically prepared Ni(OH)(2) powders.

Modern electrochemical devices require the morphological control of the active material. In this paper the synthesis of nickel hydroxide, as common active compound of such devices, is presented. The influence of ultrasound in the synthesis of nickel hydroxide from aqueous ammonia complexes is studied showing that ultrasound allows the fabrication of flower-like particles with sizes ranging in between 0.

Surface behavior of nickel powders in aqueous suspensions.

The colloidal behavior of nickel aqueous suspensions is studied and compared to that of NiO suspensions. Under acidic conditions, nickel readily dissolves, but no dissolution takes place at basic pH. Zeta potential is studied as a function of pH, showing that the isoelectric point (IEP) occurs at pH 3.

Laminar Ceramics That Exhibit a Threshold Strength.

Thin compressive layers within a laminar ceramic arrest large cracks (surface and internal) and produce a threshold strength. This phenomenon increases the damage tolerance of ceramics and will allow engineers to design reliable ceramic components for structural applications. The stress intensity factor derived for a crack sandwiched between two compressive layers suggests that the threshold strength is proportional to the residual compressive stress and the thickness of the compressive layer and is inversely proportional to the distance between the compressive layers.