Superabsorbent polymers (SAPs) are organic materials possessing high capacity to absorb and retain large volumes of water, saline and physiological solutions (at least 10–20 times their weight). The most commonly used SAPs are acrylated-based polymers that are not biodegradable or recyclable. To overcome these limits, carboxymethylcellulose (CMC) with hydroxyethylcellulose (HEC) hydrogels were synthetized in this work and dried using a supercritical assisted process at 200 bar and 45 °C. The solvent exchange procedure influenced the final aerogel morphology and, thus, the aerogel swelling ratio (SR). A solvent exchange starting from 50 % v/v ethanol, preserved the native gel nanofibrous morphology, producing a SR up to 20 times larger than the ones reported in the literature using the same process, corresponding to a water uptake larger than 500 times the weight of the dried aerogel.

超吸收性聚合物（SAP）是有机材料，具有吸收和保留大量水，盐和生理溶液（至少为其重量的10至20倍）的高能力。最常用的SAP是不可生物降解或不可回收的丙烯酸酯基聚合物。为了克服这些限制，在这项工作中合成了带有羟乙基纤维素（HEC）水凝胶的羧甲基纤维素（CMC），并使用超临界辅助工艺在200 bar和45°C下干燥。溶剂交换程序影响了最终的气凝胶形态，并因此影响了气凝胶溶胀率（SR）。从50％v / v乙醇开始的溶剂交换可保留天然的凝胶纳米纤维形态，其SR最高可达文献报道的相同方法的20倍，