Menshutina Natalia, Fedotova Olga, Abramov Andrey, Golubev Eldar, Sulkhanov Yan, Tsygankov Pavel
Department of Chemical and Pharmaceutical Engineering, Mendeleev University of Chemical Technology of Russia, Miusskaya pl. 9, 125047 Moscow, Russia.
Gels. 2024 Dec 20;10(12):845. doi: 10.3390/gels10120845.
Currently, materials with specific, strictly defined functional properties are becoming increasingly important. A promising strategy for achieving these properties involves developing methods that facilitate the formation of hierarchical porous materials that combine micro-, meso-, and macropores in their structure. Macropores facilitate effective mass transfer of substances to the meso- and micropores, where further adsorption or reaction processes can occur. Aerogels represent a promising class of materials for implementing this approach. The formation of hierarchical porous structures in aerogels can be achieved using soft and hard templating methods or by foaming techniques. This paper presents a comprehensive study of three methods for forming hierarchical porous structures in alginate aerogels: (1) employing surfactants (Pluronic F-68), (2) using zein as a pore-forming component, and (3) foaming in a carbon dioxide medium. The results of micro-CT showed that each of the methods contributes to the formation of macropores within the structure of the resulting aerogels. Size distribution curves of the detected macropores were obtained, showing the presence of macropores ranging from 16 to 323 μm in size for samples obtained using surfactants, from 5 to 195 μm for samples obtained using zein, and from 20 μm to 3 mm for samples obtained by foaming in a carbon dioxide medium. The SEM images demonstrated the macro- and mesoporous fibrous structure of the obtained materials. The nitrogen porosimetry results indicated that samples obtained using surfactants and zein are characterized by a high specific surface area (592-673 m/g), comparable to the specific surface area for an alginate-based aerogel obtained without the use of pore-forming components. However, the use of the developed methods for the formation of a hierarchical porous structure contributes to an increase in the specific mesopores volume (up to 17.7 cm/g). The materials obtained by foaming in a carbon dioxide medium are characterized by lower specific surface areas (112-239 m/g) and specific mesopores volumes (0.6-2.1 cm/g). Thus, this paper presents a set of methods for forming hierarchical porous structures that can obtain delivery systems for active substances with a controlled release profile and highly efficient platforms for cell culturing.
目前，具有特定、严格定义的功能特性的材料正变得越来越重要。实现这些特性的一种有前景的策略是开发有助于形成分级多孔材料的方法，这些材料在其结构中结合了微孔、介孔和大孔。大孔有助于物质有效地向介孔和微孔进行传质，在介孔和微孔中可以发生进一步的吸附或反应过程。气凝胶是实现这种方法的一类很有前景的材料。可以使用软模板法和硬模板法或通过发泡技术在气凝胶中形成分级多孔结构。本文对在藻酸盐气凝胶中形成分级多孔结构的三种方法进行了全面研究：（1）使用表面活性剂（普朗尼克F - 68），（2）使用玉米醇溶蛋白作为成孔成分，（3）在二氧化碳介质中发泡。显微CT结果表明，每种方法都有助于在所得气凝胶的结构内形成大孔。获得了检测到的大孔的尺寸分布曲线，结果显示，使用表面活性剂获得的样品中存在尺寸范围为16至323μm的大孔，使用玉米醇溶蛋白获得的样品中存在尺寸范围为5至195μm的大孔，通过在二氧化碳介质中发泡获得的样品中存在尺寸范围为20μm至3mm的大孔。扫描电子显微镜图像展示了所得材料的大孔和介孔纤维结构。氮孔隙率测定结果表明，使用表面活性剂和玉米醇溶蛋白获得的样品具有较高的比表面积（592 - 673 m/g），与未使用成孔成分获得的基于藻酸盐的气凝胶的比表面积相当。然而，使用所开发的方法形成分级多孔结构有助于增加比介孔体积（高达17.7 cm/g）。通过在二氧化碳介质中发泡获得的材料的特点是比表面积较低（112 - 239 m/g）和比介孔体积较低（0.6 - 2.1 cm/g）。因此，本文提出了一套形成分级多孔结构的方法，这些方法可以获得具有控释特性的活性物质递送系统以及用于细胞培养的高效平台。
