Characterization and structural properties of bamboo fibre solid foams

Abstract

In this work, cellulose fibres extracted from bamboo culms were used to fabricate two types of cellular materials: rigid foams and fibrous networks. A relatively simple and low-technology fabrication method is presented, using natural binders and blowing agents to manufacture rigid foams, and fibrillation by partial hydrolysis in H2SO4 to manufacture fibrous networks. The compressive response is related to the internal microstructure and processing parameters. In the case of fibrous networks, the achievable relative density range is determined by the length of initial fibres and extent of external fibrillation. The compressive properties are dictated both by the density of the network and strength of the fibrous bridges, showing a linear stiffness-density relationship due to the length of fibres, and an inverse relationship at increased external fibrillation. The rigid foams showed an orthotropic internal microstructure but nearly isotropic compressive response, due to the influence of the interpenetrating void structure on the deformation and fracture mechanisms. The results show the potential of bamboo-fibre porous materials as low cost, lightweight structural materials.

Electrocapacitive and electrocatalytic performances of hydrochar prepared by one-step hydrothermal carbonization without further activation

“…The broad peak around 3000-3700 cm −1 confirms that the oxygen presence as −OH in hydrochar might be caused by the dehydration process during HTC [13]. The bands in the HC-H sample at 1021, 900, and 850 cm −1 are [37,38]. These chemical bonds were significantly reduced in the HC-K sample and completely disappeared in HC-KS and HC-KN, showing that water did not have a better ability to decompose lignocellulose than others, as confirmed by the SEM image as discussed previously.…”

Foam forming of fiber products: a review

“…[127] Higher densities can be produced by reducing the air content ( Figure 26) and stability of the foam or by using shorter fibers. [12,128] Moreover, drainage affects the density a lot. Especially with the applied vacuum and wet pressing, [98] it is possible to make fiber networks with a similar density (exceeding 300 kg/m 3 ) as that obtained by water forming.…”

Chemical Binder-Free and Oven-Dried Lignocellulose/Clay Composite Foams: Flame Resistance, Thermal Insulation, and Recyclability

“…25 Air/oven drying, by contrast, represents an economically competitive strategy to prepare bulky foams that feature high production efficiency, low energy intensity, relatively mild conditions, facile operation, and scalability. To achieve mechanically robust foams, chemical binders (such as borates, 26 methylene diphenyl diisocyanate, 27 and polyacrylamide 28 ) are commonly employed. However, most binders are associated with toxicity, and using binders reduces the percentage of sustainable materials in the final foam product and prevents any efforts to recycle and reuse the materials at the end of service life.…”