Irregular and suppressed elastic deformation by a structural twist in cellulose nanofibre models

Strong attractive interaction between finite element models of twisted cellulose nanofibers by intermeshing of twists

Analysis of the attractive interaction between intrinsically twisted cellulose nanofibers (CNFs) is essential to control the physical properties of the higher-order structures of CNFs, such as paper and spun fiber. In this study, a finite element model reflecting the typical morphology of a twisted CNF was used to analyze the attractive interaction forces between multiple approaching CNF models. For two parallel CNF models, when one of the CNF models was rotated 90° around the long-axis direction, the twisting periods meshed, giving the maximum attraction force. Conversely, when the two CNF models were approaching diagonally, the CNF models were closest at an angle of -3.2° (i.e., in left-handed chirality) to give the most stable structure owing to the right-handed twist of the CNF models themselves. Furthermore, the two nematic layers were closest when one nematic layer was approached at an angle of -2° (i.e., in left-handed accumulation chirality), resulting in the greatest attraction. The results characterize the unique distribution of the attractive interaction forces between twisted CNF models, and they underscore the importance of chiral management in CNF aggregates, especially intermeshing of twists.

Chirality Transfer from an Innately Chiral Nanocrystal Core to a Nematic Liquid Crystal 2: Lyotropic Chromonic Liquid Crystals

The importance of and the difference between molecular versus structural core chirality of substances that form nanomaterials, and their ability to transmit and amplify their chirality to and within a surrounding condensed medium is yet to be exactly understood. Here we demonstrate that neat as well as disodium cromoglycate (DSCG) surface-modified cellulose nanocrystals (CNCs) with both molecular and morphological core chirality can induce homochirality in racemic nematic lyotropic chromonic liquid crystal (rac-N-LCLC) tactoids. In comparison to the parent chiral organic building blocks, D-glucose, endowed only with molecular chirality, both CNCs showed a superior chirality transfer ability. Here, particularly the structurally compatible DSCG-modified CNCs prove to be highly effective since the surface DSCG moieties can insert into the DSCG stacks that constitute the racemic tactoids. Overall, this presents a highly efficient pathway for chiral induction in an aqueous medium and thus for understanding the origins of biological homochirality in a suitable experimental system.

Chirality Transfer from an Innately Chiral Nanocrystal Core to a Nematic Liquid Crystal: Surface-Modified Cellulose Nanocrystals

The vast majority of nanomaterials studied in light of their ability to transmit chirality to or amplify their chirality in a surrounding medium, constitute an achiral core with chirality solely installed at the surface by conjugation or encapsulation with optically active ligands. Here we present the inverse approach focusing on surface-modified cellulose nanocrystals (CNCs) with core chirality at both the molecular and the morphological level to quantify transmission and amplification of core chirality through space using a host nematic liquid crystal (N-LC) as reporter. We find that CNCs functionalized at the surface with achiral molecules, structurally related to the N-LC, exhibit better N-LC solubility, thereby serving as highly efficient chiral inducers. Moreover, functionalization with chiral molecules only marginally enhances the efficacy of helical distortion in the host N-LC matrix, indicating the high propensity of CNCs to transfer chirality from an inherently chiral core.