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...

Tannin/furanic rigid foams were modi ed by either polymeric 4,4’ diphenylmethane diisocyanate (pMDI) or a one-component polyurethane still presenting reactive isocyanate groups (PUR). Several di erent sequences of mixing the isocyanate and polyurethane with the chemicals used to prepare tannin-based foams were tested. Scanning electron microscopy (SEM) showed that addition of either pMDI or PUR...

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...

In this work, we have explored the feasibility of alveolar open-cell β-SiC foams as catalyst support for solar hydrogen production. For that purpose, Pt and Ru nanoparticles been obtained, by means photoassisted synthesis, on TiO2-coated tested in gas-phase production from water-ethanol mixtures a tubular reactor coupled to compound parabolic collector (CPC). Subnanometre-sized metal or metal/o...

Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solu...

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...

We attempt to meet the general design requirements for high-performance supercapacitor electrodes by combining the strategies of lightweight substrate, porous nanostructure design, and conductivity modification. We fabricate a new type of 3D porous and thin graphite foams (GF) and use as the light and conductive substrates for the growth of metal oxide core/shell nanowire arrays to form integra...

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...