Nickel–aluminide foams were synthesized from unalloyed nickel foams by using a two-step, high-activity pack-aluminizing process at 1273 K. After processing, the nickel–aluminide foams exhibited the original structure of the original nickel foams (open-cells with hollows struts and low density). Single-phase NiAl foams, with average composition within 1 wt.% of stoichiometry and with 92% open po...

Collagen I foams are used in the clinic as scaffolds to promote articular cartilage repair as they provide a bioactive environment for cells with chondrogenic potential. However, collagen I as a base material does not allow for precise control over bioactivity. Alternatively, recombinant bacterial collagens can be used as "blank slate" collagen molecules to offer a versatile platform for incorp...

The effects of metal foams on heat transfer enhancement in Phase Change Materials (PCMs) are investigated. The numerical investigation is based on the two-equation non-equilibrium heat transfer model, in which the coupled heat conduction and natural convection are considered at phase transition and liquid zones. The numerical results are validated by experimental data. The main findings of the ...

Polyurethane foam (PUF) is an outstanding material for various applications, which is manufactured by propelling liquid isocyanate-polyol mixture to form foams in the presence of blowing agent. In order to reduce the ozone depletion and environmental pollution from organic blowing agents, waterblown PU foams were prepared with various water levels (311phr), and the effects of water level on mec...

Amit Desai, Maria L. Auad, 1 Hongbin Shen and Steven R. Nutt* Gill Foundation Composites Center, Department of Chemical Engineering and Materials Science, University of Southern California, 3651 Watt Way VHE-602, Los Angeles, CA 90089-0241, USA * E-mail: [email protected] Abstract: Hybrid composite phenolic foams are reinforced with chopped glass and aramid fibers in varied proportions. The mechanic...

Open cell foams consisting of Fe and Fe-Mn oxides are prepared from metallic Fe and Mn powder precursors by the replication method using porous polyurethane (PU) templates. First, reticulated PU templates are coated by slurry impregnation. The templates are then thermally removed at 260 °C and the debinded powders are sintered at 1000 °C under N₂ atmosphere. The morphology, structure, and magne...

Lightweight and strong polymeric foams show high potential application in alleviating the global energy crisis due to their capability of reducing material resource requirements as well decreasing consumption. However, it is inevitably difficult produce lightweight polymers with satisfactory mechanical properties. Herein, we report an innovative method high-performance polypropylene (PP) by com...

Many wounds heal slowly and are difficult to manage. Therefore Negative Pressure Wound Therapy (NPWT) was developed where polymer foams are applied and a defined negative pressure removes wound fluid, reduces bacterial burden and increases the formation of granulation tissue. Although NPWT is used successfully, its mechanisms are not well understood. In particular, different NPWT dressings were...

Acoustic measurements provide convenient non-invasive means for the characterisation of materials. We show here for the first time how a commercial impedance tube can be used to provide accurate measurements of the velocity and attenuation of acoustic waves in liquid foams, as well as their effective "acoustic" density, over the 0.5-6kHz frequency range. We demonstrate this using two types of l...