Design of pores in the cellulose aerogels by using small molecules and controlling the aggregation at the interface

Kurzfassung

Porous materials of cellulose such as aerogels receive great attention in limitless applications including insulating materials, filters, purifiers, biomedicine, etc. Aerogels of cellulose are biocompatible, non-toxic and showing exceptional mechanical property. They have open porous network, low density and randomly connected nanofibrillar microstructure. Design of pores at various dimensions in cellulose aerogels will be attractive and challenging. Two different approaches of designing the pores of cellulose aerogels will be discussed. For the dissolution of cellulose, two solvent routes are employed: (a) molten salt hydrate route and (b) NaOH-urea-water medium. A series of small molecules are chosen in our studies to control the aggregation of cellulose and they have opposite physical and chemical properties. For example, in the method (a), surfactants having various HLB values are employed to design the macropores > 100 nm, whereas in the method (b), strong or weak acids are employed to adjust the meso- and macropores below 100 nm. Those small molecules can be called influencing agents which are employed during the coagulation process of cellulose. Hence the influencing agents induces the randomly connected wet-gel network formation and controls the space between the wet-gel network. The experimental conditions are kept constant in order to follow the effect of influencing agents. The data from our publications will be presented and discussed.[1-4] The products are characterized by scanning electron microscopy, computer tomography, BET specific surface area and BJH pore analyses methods. References: 1. Chem. Eur. J., 2024, 30, e202401794. 2. Molecules, 2019, 24, 2688. 3. J. Sol-Gel Sci. Technol., 2019, 89, 156–165. 4. Mater. Design, 2016, 92, 345–355.