Novel finely structured polymer aerogels using organogelators as a structure-directing component

Abstract

Sorbitol-based organogelators were used to obtain nanostructured, robust polyolefin gels that could be freeze-dried into aerogels. Finding the ideal ratio of polymer to gelator led to homogeneous, fine structures with good mechanical stability and low thermal conductivity. The influence of polymer type, molecular weight and concentration was studied with regard to structure, compressive strength and thermal conductivity and a mechanism for the structure formation was postulated. Moreover, Soxhlet extraction was shown as a route to optimize the drying process and partially recover the gelator that is required as a structure-directing component, but partially also necessary in the final composite. The materials presented here are novel and useful composite aerogels with potential applications as insulating materials, porous supports, adsorbents, catalyst carriers and membranes.