Cellulose–silica aerogels

Production of porous cellulose aerogel fibers by an extrusion process

“…Extrapolating to zero in cellulose content the conductivity of air (0.26 W/m.K) is almost achieved with a value of 0.032 W/m.K. Our thermal conductivity value for 3 wt.% cellulose aerogel monolith is well agree with the work done by Demilecamps et al [32]. In most cases, heat transfer within aerogels is based on three mechanisms: heat conduction via solid state, heat transfer from gaseous phase presents in the open-porous aerogel structure and radiative heat transfer.…”

“…The conductivity of a random 3D cellulose fiber network is therefore determined mainly by gas phase via heat conduction, here being of diffusive nature, since the pores are smaller than a micron and additionally conduction through the solid skeleton. Therefore the overall conductivity can be described by the weighted addition of heat conduction through the gas phase and solid state conduction through the cellulose fibers [32][33][34][35]. Therefore the thermal conductivity should vary linearly with the cellulose content in the range of low cellulose concentrations.…”

Mechanical reinforcement of a cellulose aerogel with nanocrystalline cellulose as reinforcer

“…3g, three regions were exhibited: (I) a linear elastic region at a very low strain (<5%), followed by (II) a long plastic deformation region with pore walls bending (the transition from linear to nonlinear stress-strain behaviour was gradual, 5-55%), and (III) densication of the porous structure, which were typical stressstrain curves of porous materials. 21 Similar compression behaviours of porous bodies were published by several literatures. 22,23 It was worthy to say that the aerogel showed very high deformability, up to 85-90% strain without any break (Fig.…”

Mechanical and thermal properties of nanofibrillated cellulose reinforced silica aerogel composites

“…Homogenous distributions of cellulose is better achieved using "one pot" synthesis concepts, however issues with solubility, dispersibility, and chemical surface reactions may lead to undesired microstructures and properties [30]. While, these studies have composite materials that are relatively mechanically robust compared to neat silica aerogel materials, the thermal conductivity values reported for the composite materials of 26e45 mW/m K are substantially higher than those of neat silica aerogel systems [31].…”