Directional freeze-casting – a process used to create foams with elongated, aligned pores applied so far exclusively for ceramics – is demonstrated for titanium foams. An aqueous slurry of <45 lm titanium powders was directionally solidified, resulting in a powder preform consisting of elongated, aligned dendrites of pure ice separated by interdendritic regions with high powder content. After f...

It is well known that foaming can become a major problem during large-scale recombinant protein bioprocesses; the vigorous stirring and introduction of gases to maintain the required dissolved oxygen (DO) concentration for the organism [1] in addition to the growth medium and protein products themselves [2], can result in the formation and stabilization of foams consisting of gas-filled liquid ...

Alginates in the format of scaffolds provide important functions as materials for cell encapsulation, drug delivery, tissue engineering and wound healing among others. The method for preparation of alginate-based foams presented here is based on homogeneous, ionotropic gelation of aerated alginate solutions, followed by air drying. The method allows higher flexibility and better control of the ...

Abstract Nanofiller reinforcing agents can significantly improve the strength and modulus of polymer foams. But these improvements are often accompanied by changes in foam density (or equivalently the expansion ratio or void volume). The efficacy of nanofillers as reinforcing agents can only be judged once the density differences are accounted for. We review the literature and show that represe...

When increasing the wood fiber (WF) content in extruded wood fiber/plastic composites (WPC) foams, a good balance between reducing the cost and obtaining good cell morphology should be maintained. This study examines the relationship between WF content and the foam morphology in WPC foams. The role of WF as cell nucleating agent at low concentrations (10 wt.%) was observed, as WPC foam with 10 ...

Lignosulfonate and lignosulfonate hydrolyzed under alkaline conditions were used as the polyol components in polyurethane foam formulations. Although the treatment increased hydroxyl group abundance, it did not improve the applicability of hydrolyzed lignosulfonate in polyurethane foam. Thus, the use of original lignosulfonate yielded foams of thermal stability and mechanical properties compara...

To more closely mimic the native cellular microenvironment, 3D scaffolds derived from the extracellular matrix (ECM) are being developed as alternatives to conventional 2D culture systems. In the present study, we established methods to fabricate nonchemically cross-linked 3D porous foams derived entirely from decellularized porcine left ventricle (DLV) for use as an in vitro cardiac cell cultu...

The structure and dynamics of three-dimensional foams are probed quantitatively by exploiting the strong multiple scattering of light that gives foams their familiar white color. Approximating the propagation of light as a diffusion process, transmission measurements provide a direct probe of the average bubble size. A model for dynamic light scattering is developed that can be used to interpre...

INTRODUCTION Metallic foams have been favoured for orthopaedic research and testing purposes for its open-celled, interconnected structure with adjustable densities but without the highly variable and inhomogeneous nature of trabecular bones. Mechanical behaviour of metallic foams has been investigated in numerous studies, although how their properties compare with those of trabecular bones is ...

We present a one-dimensional, multiscale mass-spring model to describe the response of vertically aligned carbon nanotube (VACNT) foams subjected to uniaxial, high-rate compressive deformations. The model uses mesoscopic dissipative spring elements composed of a lower level chain of asymmetric, bilateral, bistable elastic springs to describe the experimentally observed deformation-dependent str...