Porous hydroxyapatite-polyhydroxybutyrate (HA-PHB) composites were fabricated by infiltrating PHB micro-/nanoparticles into rigid HA scaffolds via centrifugation, followed by subsequent heating at 175°C to melt the PHB into the scaffolds. HA scaffolds were obtained by heating trabecular bovine femur bone at 1350°C to remove the organic and sinter the HA. PHB particles were recovered and purifie...

statement of problem: the degree of conversion depends on the material composition, light source properties, distance from light source, light intensity, curing time, and other factors such as shade and translucency. objectives: in the present study, we evaluated the effects of different light- curing modes and shades of methacrylate and silorane-based resin composites on the degree of conversi...

this research investigates the effect of the post-cure time on the residual stresses in laminated composites. laminated composites were made of t300 carbon fibers and epoxy resin. the post-cure process was carried out at the constant temperature of 120 °c for 6 and 12 hours for two specimens. the slitting method was employed to determine through-thickness residual stress distribution of the com...

A one-step method which involves exfoliating graphite materials (GIMs) off into graphene materials (GEMs) in aqueous suspension of CL-20 and forming CL-20/graphene materials (CL-20/GEMs) composites by using ball milling is presented. The conversion of mixtures to composite form was monitored by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The impact sensitivities of CL...

Measurement of the strength of brittle materials, such as resin composites, is extremely difficult. Micro-indentation hardness testing is a convenient way of investigating the mechanical properties of a small volume of material. In this study, the mechanical properties of five commercially available flowable resin composites were investigated by the dynamic micro-indentation method. Additionall...

Silver nanoparticle (Ag NP)/chitosan (Ch) composites with antiviral activity against H1N1 influenza A virus were prepared. The Ag NP/Ch composites were obtained as yellow or brown floc-like powders following reaction at room temperature in aqueous medium. Ag NPs (3.5, 6.5, and 12.9 nm average diameters) were embedded into the chitosan matrix without aggregation or size alternation. The antivira...

Novel composites were synthesized from keratin (KER), cellulose (CEL) and chitosan (CS). The method is recyclable because majority (>88%) of [BMIm+Cl-], an ionic liquid (IL), used as the sole solvent, was recovered for reuse. Experimentally, it was confirmed that unique properties of each component remain intact in the composites, namely bactericide (from KER and CS) and anti-inflammatory prope...

statement of problem: there are controversial reports regarding physical and mechanical properties of resin composites and glass ionomer cements. some revealed higher strength and hardness for resin composites while others showed a comparable value for glass ionomer cements. evaluation of mechanical properties of different types of resin composites in comparison with resin modified glass ionome...

in this research, effects of concentration and time of silane treatment of rice straw flour on the morphology and mechanical strengths of rice straw flour/polypropylene composites were investigated. tri ethoxy vinyl silane (c8h18o3si) with 98% purity in two concentrations of 5 and 10%, that each concentration had two immersion times including, 45 and 90 min for using treatment rice straw flour....