Ambient‐Dried Cellulose Nanofibril Aerogel Membranes with High Tensile Strength and Their Use for Aerosol Collection and Templates for Transparent, Flexible Devices

Abstract

The application potential of cellulose nanofibril (CNF) aerogels has been hindered by the slow and costly freeze-or supercritical drying methods. Here, CNF aerogel membranes with attractive mechanical, optical and gas transport properties are prepared in ambient conditions with a facile and scalable process. Aqueous CNF dispersions are vacuum-filtered and solvent exchanged to 2-propanol and further to octane, followed by ambient drying. The resulting CNF aerogel membranes are characterized by high transparency (> 90 % transmittance), stiffness (6 GPa Young's modulus, 10 GPa . cm 3 /g specific modulus), strength (97 MPa tensile strength, 161 MPa . m 3 /kg specific strength), mesoporosity (pore diameter 10-30 nm, 208 m 2 /g specific surface area) and low density (~0.6 g/cm 3 ). They are gas-permeable thus enabling collection of nanoparticles (for example, single-walled carbon nanotubes, SWCNT) from aerosols under pressure gradients. The membranes with deposited SWCNT can be further compacted to transparent, conductive and flexible conducting films (90% specular transmittance at 550 nm 1 and 300 Ω/ □ sheet resistance with AuCl3-salt doping). Overall, the developed aerogel membranes pave way towards use in gas filtration and transparent, flexible devices.

All-nanocellulose nonvolatile resistive memory

“…[10][11][12][13][14][15][16] Therefore, nanopaper has recently received much attention as a substrate for flexible electronics. 9,[17][18][19][20][21][22][23][24][25][26][27][28][29] To date, various electronic devices including organic/inorganic thin-film transistors, 9,21-23 light-emitting diodes, 24 solar cells, 23,25,26 antennas 27,28 and triboelectric generators 29 have been demonstrated on nanopaper substrates. However, a nonvolatile memory, which is the essential component for IoE technology, has not been demonstrated on a nanopaper substrate so far.…”

A High‐Performance, Low‐Tortuosity Wood‐Carbon Monolith Reactor

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high tortuosity and complex flow channels, which may cause high flow resistance, specifically due to agglomeration when the reactant gas flows through the Ni catalysts. [34][35][36][37] Mechanically superstrong composites have been demonstrated by incorporating cellulose nanofibers. For example, transparent films based on cellulose nanofibers are promising replacements of plastics for biodegradable electronics.

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Nanocellulose in Thin Films, Coatings, and Plies for Packaging Applications: A Review

“…By contrast, more opaque films have been achieved in cases where cellulose reinforcements were either poorly wetted, agglomerated (Santos et al 2014;Ambrosio-Martin et al 2015b), or simply large relative to the wavelength of light . Toivonen et al (2015a) demonstrated for the first time that transparent films can be achieved even in the case where aerogel technology had been used in the initial film formation; subsequent compaction yielded transparent, flexible films. …”

“…Tammelin et al (2013) described how the application of a waterbased nanocellulose formulation to a support surface, followed by drying in place, can be a convenient way to avoid problems of shrinkage in separately-prepared films. Toivonen et al (2015a) showed that the transparency of films could be retained effectively by using REVIEW ARTICLE bioresources.com . "Nanocellulose in packaging," BioResources 12(1), 2143-2233.…”