Pore-Refined Biobased Aerogel for Gas-Sensitive Intelligent Colorimetric Tags

Biobased materials with superior porosity are the preferred choice for high-performance and environmentally friendly gas sensors. Here, a pore-refined colorimetric aerogel with significant-improved porous structure and mechanical integrity is developed through the strategic incorporation of hydrophilic poly(vinyl alcohol) (PVA) in nanocellulose, evidenced by a 14.35-fold increase in surface area, a 21.24-fold improvement in pore volume, and a 16.91-fold rise in gas adsorption–desorption capacity, along with advancements in both static (5.20-fold) and dynamic (5.59-fold) compressive strengths. The enhancement in performance is attributed to the addition of PVA, which promotes uniformity in the gel network and forms hydrogen bonds with cellulose, thereby minimizing structural changes during drying and refining of the pore structure. The aerogels demonstrate sensitive, gradient, recognizable, and highly reversible color changes to ammonia stimuli (down to 10 ppm). Intelligent tags based on the enhanced aerogels demonstrate earlier identification of spoilage in monitoring different types of meat, proving their potential in smart packaging.