Click-Chemistry-Enabled Functionalization of Cellulose Nanocrystals with Single-Stranded DNA for Directed Assembly.

Controlling the self-assembly of cellulose nanocrystals (CNCs) requires precise control over their surface chemistry for the directed assembly of advanced nanocomposites with tailored mechanical, thermal, and optical properties. In this work, in contrast to traditional chemistries, we conducted highly selective click-chemistry functionalization of cellulose nanocrystals with complementary DNA strands via a three-step hybridization-guided process. By grafting terminally functionalized oligonucleotides through copper-free click chemistry, we successfully facilitated the assembly of brushlike DNA-modified CNCs into bundled nanostructures with distinct chiral optical dichroism in thin films.

Magneto-Responsive Chiral Optical Materials: Flow-Induced Twisting of Cellulose Nanocrystals in Patterned Magnetic Fields.

Magnetic fields have been used to uniformly align the lyotropic chiral nematic (cholesteric) liquid crystalline (LC) phase of biopolymers to a global orientation and optical appearance. Here, we demonstrate that, in contrast, weak and patterned magnetic field gradients can create a complex optical appearance with the variable spatial local organization of needle-like magnetically decorated cellulose nanocrystals. The formation of optically patterned thin films with left- and right-handed chiral and achiral regions is observed and related to local magnetic gradient-driven vortices during LC suspension flow.

Ultrathin Films of MXene Nanosheets Decorated by Ionic Branched Nanoparticles with Enhanced Energy Storage Stability.

Two-dimensional (2D) materials such as MXenes have shown great potential for energy storage applications due to their high surface area and high conductivity. However, their practical implementation is limited by their tendency to restack, similar to other 2D materials, leading to a decreased long-term performance. Here, we present a novel approach to addressing this issue by combining MXene (TiCT) nanosheets with branched ionic nanoparticles from polyhedral oligomeric silsesquioxanes (POSS) using an amphiphilicity-driven assembly for the formation of composite monolayers of nanoparticle-decorated MXene nanosheets at the air-water interface.

Bio-Templated Chiral Zeolitic Imidazolate Framework for Enantioselective Chemoresistive Sensing.

Chiral metal-organic frameworks (MOFs) have gained rising attention as ordered nanoporous materials for enantiomer separations, chiral catalysis, and sensing. Among those, chiral MOFs are generally obtained through complex synthetic routes by using a limited choice of reactive chiral organic precursors as the primary linkers or auxiliary ligands. Here, we report a template-controlled synthesis of chiral MOFs from achiral precursors grown on chiral nematic cellulose-derived nanostructured bio-templates.

Reconfiguration of Langmuir Monolayers of Thermo-Responsive Branched Ionic Polymers with LCST Transition.

Thermo-responsive ionic polymers have the ability to form adaptive and switchable morphologies, which may offer enhanced control in energy storage and catalytic applications. Current thermo-responsive polymers are composed of covalently attached thermo-responsive moieties, restricting their mobility and global dynamic response. Here, we report the synthesis and assembly at the water-air interface of symmetric and asymmetric amphiphilic thermo-responsive branched polymers with weakly ionically bound arms of amine-terminated poly(-isopropylacrylamide) (PNIPAM) macro-cations.

Flexible Sustained Ionogels with Ionic Hyperbranched Polymers for Enhanced Ion-Conduction and Energy Storage.

Flexible and mechanically robust gel-like electrolytes offer enhanced energy storage capabilities, versatility, and safety in batteries and supercapacitors. However, the trade-off between ion conduction and mechanical robustness remains a challenge for these materials. Here, we suggest that the introduction of ionic hyperbranched polymers in structured sustained ionogels will lead to both enhanced ion conduction and mechanical performance because of the hyperbranched polymers' ionically conductive groups and the complementary interfacial interactions with ionic liquids.

Cellulose Nanocrystals' Assembly under Ionic Strength Variation: From High Orientation Ordering to a Random Orientation.

We discuss the effect of the ionic strength and effective charge density on the final structural organization of cellulose nanocrystals (CNCs) after drying suspensions with different ionic strengths in terms of quantitative characteristics of the orientation order, rarely considered to date. We observed that increasing the ionic strength in the initial suspension results in continuous shrinking of the helical pitch length that shifts the photonic band gap to a far UV region from the visible range (from 400 to 250 nm) because of the increase in the helical twisting power from 4 to 6 μm and doubling of the twisting angle between neighboring monolayers from 5.5 to 9°.

Monolithic Chiral Nematic Organization of Cellulose Nanocrystals under Capillary Confinement.

We demonstrate bioenabled crack-free chiral nematic films prepared a unidirectional flow of cellulose nanocrystals (CNCs) in the capillary confinement. To facilitate the uniform long-range nanocrystal organization during drying, we utilized tunicate-inspired hydrogen-bonding-rich 3,4,5-trihydroxyphenethylamine hydrochloride (TOPA) for physical cross-linking of nanocrystals with enhanced hydrogen bonding and polyethylene glycol (PEG) as a relaxer of internal stresses in the vicinity of the capillary surface. The CNC/TOPA/PEG film is organized as a left-handed chiral structure parallel to flat walls, and the inner volume of the films displayed transitional herringbone organization across the interfacial region.

Switchable Photonic Bio-Adhesive Materials.

A soft photonic bio-adhesive material is designed with real-time colorimetrical monitoring of switchable adhesion by integrating a responsive bio-photonic matrix with mobile hydrogen-binding networking. Synergetic materials sequencing creates a unique iridescent appearance directly coupled with both adhesive ability and shearing strength, in a highly reversible manner. The responsive photonic materials, having a physically hydrogen-bonded chiral nematic organization, vary their adhesion strength due to a transition in cohesive and interfacial failure mechanism in humid surroundings.

Bio-Organic Chiral Nematic Materials with Adaptive Light Emission and On-Demand Handedness.

Real-time active control of the handedness of circularly polarized light emission requires sophisticated manufacturing and structural reconfigurations of inorganic optical components that can rarely be achieved in traditional passive optical structures. Here, robust and flexible emissive optically-doped biophotonic materials that facilitate the dynamic optical activity are reported. These optically active bio-enabled materials with a chiral nematic-like organization of cellulose nanocrystals with intercalated organic dye generated strong circularly polarized photoluminescence with a high asymmetric factor.

A Helicene Nanoribbon with Greatly Amplified Chirality.

We report the synthesis and characterization of a chiral, shape-persistent, perylene-diimide-based nanoribbon. Specifically, the fusion of three perylene-diimide monomers with intervening naphthalene subunits resulted in a helical superstructure with two [6]helicene subcomponents. This π-helix-of-helicenes exhibits very intense electronic circular dichroism, including one of the largest Cotton effects ever observed in the visible range.

Abiotic tooth enamel.

Tooth enamel comprises parallel microscale and nanoscale ceramic columns or prisms interlaced with a soft protein matrix. This structural motif is unusually consistent across all species from all geological eras. Such invariability-especially when juxtaposed with the diversity of other tissues-suggests the existence of a functional basis.