Pillar[5]arene-Based Self-Assembled Organic Nanosheets: Engineered for Superior Mechanical Strength and Ion...

The widely utilized design of solid-state conductors encounters a compromise between ion conductivity and mechanical strength. Here, a supramolecular approach is proposed for addressing this issue, utilizing three solution-processable pillararene-based self-assembled organic nanosheets (SONs). The efficacy of the mechanical and ion-conducting properties of the six composite films obtained from SONs with two different polymers are linked to the number of H-bonding sites, -H···π interactions and hydrophilicity. The study demonstrates that augmentation of H-bonding sites and hydrophilicity is essential in achieving the highest level of toughness (66,328 ± 424 kJ/m³), while increasing hydrophobicity and decreasing H-bonding sites are critical for optimizing the Young's modulus (659.1 ± 22 MPa). The conductivity analysis of Li, Na, and K ions indicated that H-bonding sites, hydrophilicity, and the films' flexibility are crucial for achieving the highest K-ion conductivity of 7.1 × 10^-3 S cm^-1, along with a maximum transport number of 0.86 at 298 K. The computational studies elucidate the stabilization energy, the nature of the radial distribution function plot, and the distance traveled over time, ultimately determining trends among three ions, pillararene derivatives, and two polymers. This study articulates a supramolecular design strategy for pillararene aimed at developing stretchable ion conductors suitable for energy storage devices.