Enzymatic Polysaccharide-Based Aerogel Absorbents for Sustainable Personal Hygiene Applications

Abstract

Polysaccharide-based aerogels have attracted attention as sustainable alternatives for absorbent products in personal hygiene. They present greener alternatives to the commonly used polyacrylates and meet the requirements of biodegradability, biocompatibility, and a more benign hazard potential. The polysaccharide utilized in this study is α-1,3-glucan produced via the enzymatic polymerization of glucose from sucrose. Here, we investigate cross-linking of the glucan with various inorganics to produce hybrid aerogels with three-dimensional (3D) interwoven microstructures, superior structural integrity, and fluid absorption capacity suitable for personal hygiene applications. We capitalize on the narrow solubility window of the glucan under alkaline conditions and prepare precursor hydrogels via a simple, acid-assisted precipitation method. The inclusion of inorganics (MgO, CaO, and TiO 2 ) during the neutralization step enhances the mechanical strength of the hybrid hydrogels which are converted subsequently to aerogels in a freeze-drying process. These hybrid aerogels, namely, TiO 2 /glucan, CaO/glucan, and MgO/glucan, display improved yield stress doubling that of the aerogel derived directly from glucan and higher absorption capacity toward deionized water in two different sorption experiments (with and without load). For commercially relevant hygiene applications, the absorption capacities of the aerogels toward model urine and menstrual fluids are assessed, and the absorption capacities of the TiO 2 /glucan hybrid aerogels are on par with commercial diapers and surpass sanitary pads due to the interplay of the glucan neutral charge and favorable hierarchical structure that enables effective uptake of the fluids. These findings indicate that the inorganic/glucan-based aerogels hold promise as viable sustainable alternatives to absorbents used in commercial hygiene applications such as sanitary pads and diapers.

Ambient-Pressure-Dried Biomass Aerogel toward Robust Cross-Linked Networks and Exceptional Mechanical Performances during Combustion

“…With the increasing global warming and the depletion of petrochemical resources, the development of sustainable insulating materials has become a global concern. − Featuring low density, low thermal conductivity, and abundant sources, biomass aerogels have been considered promising candidates for substitution of petroleum-based polymeric foams. − Unfortunately, a biomass aerogel usually suffers from poor mechanical strength and flammability . What is more, the thermal insulators also need to maintain robust properties to resist the collapse of a building under harsh conditions, e.g., high temperatures and fire scenarios, thus allowing more time for rescuing and escaping, especially in high-rise buildings. , Additive − and reactive − flame retardants were introduced into the aerogel to enhance both mechanical and flame-retardant performances.…”