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...

Enhancing the phase change material properties by an energy-efficient one-step preparation method using organogelator–polyolefin composites

“…Because paraffin is not the ideal solvent for the gelator-polyolefin system, the structures are slightly coarser, but still mesoporous. This observation is in agreement with the findings in previous work 47 , that using cyclohexane instead of aromatic solvents (like TCB) yielded coarser aerogels.…”

“…Of course, there are alternative PCM composites such as PP aerogel and EG stabilized materials, but these are much more complex and cost-intensive to produce. The stabilization of the gel network, which was shown in a previous work 47 , has a significant positive effect. This innovation gives the material a fundamental advantage over the established systems.…”

“…To prove that the network structure described in the previous work 47 is also formed in paraffin as the solvent, different TBPMN/polyolefin samples were synthesized and then exchanged against cyclohexane via Soxhlet extraction. 47 After subsequent freeze drying the samples were analyzed by SEM. Figure 4 shows the obtained aerogel structure of an extracted paraffin-derived sample compared to the structure obtained from TCB.…”

“…Exemplary measurements with 50 cycles and 24 h of thermal stress showed no further mass loss. The composition of the aerogels described in the previous paper 47 does not necessarily represent the ideal one as PCM support; therefore, different formulations were evaluated. The requirement here is to obtain a stable and PCM-retaining network and not the finest porous structure possible, as it is required for thermal insulation applications.…”

“…Recently, we demonstrated that by combining organogelators with suitable high molecular weight polymers, for example polyolefins, mechanically robust composite aerogels can be obtained, because a thin polymer film on the gelator fibers reinforces the network. 47 Here, we use such composites as support for PCMs such as paraffin or polyethyleneglycol. Importantly, we show that instead of subsequent loading of the support with PCMs, also a one-step fabrication directly in the PCM as solvent is possible and that robust materials at very high PCM/carrier ratios of up to 39 : 1 can be obtained.…”