Nanocelluloses (cellulose nanocrystals, CNCs, or cellulose nanofibrils, CNFs) are the elementary reinforcing constituents of plant cell walls. Because of their pronounced slenderness and outstanding intrinsic mechanical properties, nanocelluloses constitute promising building blocks for the design of future biobased high-performance materials such as nanocomposites, dense and transparent films, continuous filaments, and aerogels and foams. The research interest in nanocellulose-based aerogels and foams is recent but growing rapidly. These materials have great potential in many engineering fields, including construction, transportation, energy, and biomedical sectors. Among the various processing routes used to obtain these materials, ice-templating is one of the most regarded, owing to its simplicity and versatility and the wide variety of porous materials that this technique can provide. The focus of this review is to discuss the current state of the art and understanding of ice-templated porous nanocellulose-based materials. We provide a review of the main forming processes that use the principle of ice-templating to produce porous nanocellulose-based materials and discuss the effect of processing conditions and suspension formulation on the resulting microstructures of the materials.

The sensitivity of bio-based materials to moisture and biological agents limits their use in tropical regions. This study evaluates the durability of gypsum-based composites reinforced with pineapple leaf fibres, subjected to accelerated ageing in a humid atmosphere saturated at 91% RH and in a fungal environment on Sabouraud medium (pH 5.6). A D-optimal design was used to analyse the combined effects of fibre volume fraction, conditioning time, and type of ageing medium on six properties: mass gain, density, volumetric deformation, flexural strength, and modulus of elasticity. Increasing fibre content promotes water absorption, with mass gains of up to 12% in humid conditions and 70% in a fungal environment, associated with notable mechanical degradation (elastic modulus reduced by up to 30% and hardness by up to 25% after six months). Antagonistic effects were observed: at low content (\(\:<\)1 ), fibres maintain internal cohesion, while at high content and longer durations, hyphae and spore penetration at the fibre-gypsum interface weakens the matrix. Polynomial models (\(\:{R}^{2}>\) 0.90) reliably predict property variations and support optimisation of fibre dosage. Microscopic analyses confirmed these alterations and provide a framework for optimising the use of gypsum–fibre composites in humid or tropical environments.