The production of biopolymeric aerogels, for tissue engineering, currently involves three steps: gelation (hydrogel), solvent exchange (alcogel), and supercritical drying (aerogel). The alcogel formation, the longest step, can be optimised by exploring high pressures/mild temperatures. This work aimed to integrate/optimise the production process of alginate/gelatine aerogels, by performing solvent exchange and drying continuously within the same equipment. High-pressure solvent exchange (HPSE) was compared with the conventional method by analysing the alcogel and solvent with two complementary analytical techniques: Differential Scanning Calorimetry (DSC) and Refractive Index (RI). HPSE resulted in a faster solvent exchange, reducing 86 % of the processing time. The solvent exchange conditions did not significantly affect the aerogel structure, density, porosity, and surface area. Still, HPSE and the drying time influenced pore distribution and decreased mechanical properties. The drying stage was optimised to 2 h, showing the feasibility of integrating solvent exchange and supercritical drying for alginate-gelatine aerogels production.

中文翻译：

---

醇凝胶形成分析：scCO2 气凝胶生产的重要一步


用于组织工程的生物聚合气凝胶的生产目前涉及三个步骤：凝胶化（水凝胶）、溶剂交换（醇凝胶）和超临界干燥（气凝胶）。醇凝胶的形成是最长的步骤，可以通过探索高压/温和温度来优化。这项工作旨在通过在同一设备内连续进行溶剂交换和干燥来整合/优化海藻酸盐/明胶气凝胶的生产过程。通过使用两种互补的分析技术：差示扫描量热法 (DSC) 和折射率 (RI) 分析醇凝胶和溶剂，将高压溶剂交换 (HPSE) 与传统方法进行比较。 HPSE 实现了更快的溶剂交换，减少了 86% 的处理时间。溶剂交换条件没有显着影响气凝胶的结构、密度、孔隙率和表面积。尽管如此，HPSE 和干燥时间仍会影响孔隙分布并降低机械性能。干燥阶段优化为2h，显示了将溶剂交换和超临界干燥相结合用于海藻酸盐-明胶气凝胶生产的可行性。