Sclerotization-Inspired Aminoquinone Cross-Linking of Thermally Insulating and Moisture-Resilient Biobased Foams

Abstract

Thermally insulating foams and aerogels based on cellulose nanofibrils (CNFs) are promising alternatives to fossil-based thermal insulation materials. We demonstrate a scalable route for moisture-resilient lightweight foams that relies on sclerotization-inspired Michael-type cross-linking of amine-modified CNFs by oxidized tannic acid. The solvent-exchanged, ice-templated, and quinone-tanned cross-linked anisotropic structures were mechanically stable and could withstand evaporative drying with minimal structural change. The low-density (7.7 kg m –3 ) cross-linked anisotropic foams were moisture-resilient and displayed a compressive modulus of 90 kPa at 98% relative humidity (RH) and thermal conductivity values close to that of air between 20 and 80% RH at room temperature. Sclerotization-inspired cross-linking of biobased foams offers an energy-efficient and scalable route to produce sustainable and moisture-resilient lightweight materials.

Synthesis and Application of Cellulose-Polyethyleneimine Composites and Nanocomposites: A Concise Review

“…Another interesting approach is the one recently reported by Kriechbaum and coworkers. They described the production of an aerogel by adsorbing PEI on TOCNF and then promoting the covalent cross-linking by means of a Michael-type reaction between oxidized catechol-containing tannin and PEI amines, followed by a drying step via evaporation [56]. Another interesting approach is the one recently reported by Kriechbaum and coworkers.…”

Biomass-derived cellulose nanofibers and iron oxide-based nanohybrids for thermal insulation application

“…This iron oxide@CNF nanohybrid is a highly efficient thermal insulator as compared to previously reported nanocellulose-based aerogels in terms of some essential important properties, i.e., mechanical strength, thermal insulation and re retardancy. 41,42 We envisage that these nanohybrid materials with improved material properties may serve as a potential next-generation building insulating material.…”

A Stiff, Tough, and Thermally Insulating Air- and Ice-Templated Plant-Based Foam

“… 4 , 18 , 44 − 47 The data point for IT CNF has been reported. 27 (c–e) Digital photographs of an AIT CNF-MC-TA foam weighing 72.3 mg, without and with weights.…”

“… 25 Conductometric titration 26 indicated a surface carboxyl content of 1.10 mmol/g, and atomic force microscopic measurements showed an average CNF diameter of 3.0 ± 0.6 nm. 27 Deionized water was used for all experiments.…”