Breakthrough in chitosan aerogel reinforcement using silk microfibers

The study investigates the use of silk microfibers with different aspect ratios to reinforce chitosan aerogels, significantly improving their mechanical properties and liquid transportation capabilities through directional freeze casting.

Chitosan aerogels, known for their lightweight, high porosity, and bioactivity, have broad application prospects but are limited by low mechanical strength. To address this, researchers introduced silk microfibers with two distinct aspect ratios—small (1–3) and large (50–100)—to create embedding and bridging structures within the aerogels. The results showed remarkable improvements in compressive strength, with the large aspect ratio fibers yielding the best performance.

The study utilized directional freeze casting to create oriented pore structures in the aerogels. The small aspect ratio silk microfibers (SmSF) embedded within individual chitosan lamellae, while the large aspect ratio fibers (LmSF) traversed across adjacent lamellae. This structural difference led to distinct mechanical behaviors. The compressive strength of pure chitosan aerogel increased from 61.67 kPa to 82.13 kPa with SmSF and 165.03 kPa with LmSF. The deformation mechanisms shifted from bending-dominated to crumpling-dominated, enhancing overall stability.

In addition to mechanical improvements, the silk microfibers also affected the liquid transportation properties of the aerogels. SmSF enhanced capillary rise by increasing surface roughness and forming microchannel-like structures, while LmSF hindered liquid flow by increasing tortuosity. This dual effect highlights the versatility of silk microfibers in modifying aerogel properties.

The findings of this study provide a novel strategy for optimizing the structural design and application properties of chitosan materials using biomass-derived fillers. This approach is expected to be applicable to other biopolymer systems, promoting sustainable material development.

See the article:

DOI

https://doi.org/10.1016/j.jobab.2025.03.006

Original Source URL

https://www.sciencedirect.com/science/article/pii/S2369969825000210

Journal

Journal of Bioresources and Bioproducts