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Spherical confinement of cholesteric liquid crystal (ChLC) droplets is emerging as an intriguing approach for achieving complex ordered structures for photonic applications and beyond. Previously, this has been achieved primarily through microfluidic assembly utilizing immiscible solvents or immiscible mesogen–solvent systems, such as oil–water or thermotropic liquid crystal–water systems, respectively. Here, we show the spontaneous assembly of spherical ChLC droplets with isotropic cores from lyotropic liquid crystals of mixed nanorods containing boron nitride nanotubes (BNNTs) and cellulose nanocrystals (CNCs) in all-aqueous environments. We show that the mixing of as low as 0.094 vol % of pectin-coated BNNTs with isotropic dispersions of 3.20 ± 0.04 vol % of CNCs enables the self-assembly of spherical ChLC droplets of micrometer size in water. This is potentially caused by the larger-aspect-ratio BNNTs modulating the overall nanorod alignment within the cholesteric shell of the resulting liquid crystal-in-water system of BNNT/CNC mixtures. Specifically, the size and negative charge of pectin-coated BNNTs are compatible with the negatively charged CNC template. By slightly increasing the BNNT concentration up to 0.121 vol %, we observed the thickness of ChLC shells to grow by roughly 53%, suggesting a synergistic liquid crystal phase behavior in BNNT/CNC mixtures. These findings provide important insights into the scalable, water-based self-assembly of mixed nanorod systems with integrated properties in a spherical confinement, broadening applications for photonics, biochemical sensing, optical films, and nanomaterial templating. 

Peripheral nerve injuries (PNIs) have a significant impact on the quality of life for patients suffering from trauma or disease. In injuries with critical nerve gaps, PN regeneration requires tissue scaffolds with appropriate physiological properties that promote cell growth and functions. Hydrogel scaffolds represent a promising platform for engineering soft tissue constructs that meet key physiological requirements. Nonetheless, ongoing innovation remains essential, as current designs continue to fall short of replicating the functional performance of autografts in bridging critical-sized nerve defects. In this study, gelatin methacrylate (gelMA)-based hydrogels are evaluated to fully characterize their pore structure, compressive stiffness, viscoelasticity, and 3D bioprintability. Hyaluronic acid (HA) and single-walled carbon nanotubes (SWCNTs) are explored as gelMA additives to modify viscoelastic and electrically conductive properties, respectively. Finally, Schwann cell (SC) and human umbilical vein endothelial cell (HUVEC) growth and functions are quantified to assess the biocompatibility of the hydrogel composites as materials for nerve scaffold fabrication. It was found that the microstructure and mechanical properties of gelMA-based hydrogels can be precisely controlled by modifying the concentrations of each component. The addition of HA led to altered viscoelastic properties of the cured structures and SWCNTs increased electrical conductivity, with both additives maintaining cytocompatibility while influencing the protein expression of both SCs and HUVECs. These composite hydrogels have potential in PNI regeneration applications. 

The integration of aryl diazonium and carbon nanotube chemistries has offered rich and versatile tools for creating nanomaterials of unique optical and electronic properties in a controllable fashion. The diazonium reaction with single-wall carbon nanotubes (SWCNTs) is known to proceed through a radical or carbocation mechanism in aqueous solutions, with deuterated water (D2O) being the frequently used solvent. Here, we show strong water solvent isotope effects on the aryl diazonium reaction with SWCNTs for creating fluorescent quantum defects using water (H2O) and D2O. We found a deduced reaction constant of ∼18.2 times larger value in D2O than in H2O, potentially due to their different chemical properties. We also observed the generation of new defect photoluminescence over a broad concentration range of diazonium reactants in H2O, as opposed to a narrow window of reaction conditions in D2O under UV excitation. Without UV light, the physical adsorption of diazonium on the surface of SWCNTs led to the fluorescence quenching of nanotubes. These findings provide important insights into the aryl diazonium chemistry with carbon nanotubes for creating promising material platforms for optical sensing, imaging, and quantum communication technologies. 

Glyconanomaterials with unique nanoscale property and carbohydrate functionality show vast potential in biological and biomedical applications. We investigated the interactions of noncovalent complexes of single-wall carbon nanotubes that are wrapped by disaccharide lactose-containing glycopolymers with the specific carbohydrate-binding proteins. The terminal galactose (Gal) of glycopolymers binds to the specific lectin as expected. Interestingly, an increased aggregation of nanotubes was also observed when interacting with a glucose (Glc) specific lectin, likely due to the removal of Glc groups from the surface of nanotubes resulting from the potential binding of the lectin to the Glc in the glycopolymers. This result indicates that the wrapping conformation of glycopolymers on the surface of nanotubes potentially allows improved accessibility of the Glc for specific lectins. Furthermore, it shows that the interaction between Glc groups in the glycopolymers and nanotubes play a key role in stabilizing the nanocomplexes. Overall, our results demonstrate that nanostructures can enable conformation-dependent interactions of glycopolymers and proteins and can potentially lead to the creation of versatile optical sensors for detecting carbohydrate-protein interactions with enhanced specificity and sensitivity. 

Effectively translating the promising properties of boron nitride nanotubes (BNNTs) into macroscopic assemblies has vast potential for applications, such as thermal management materials and protective fabrics against hazardous environment. We spun fibers from aqueous dispersions of BNNTs in polyvinyl alcohol (PVA) solutions by a wet spinning method. Our results demonstrate that BNNTs/PVA fibers exhibit enhanced mechanical properties, which are affected by the nanotube and PVA concentrations, and the coagulation solvent utilized. Compared to the neat PVA fibers, we obtained roughly 4.3-, 12.7-, and 1.5-fold increases in the tensile strength, Young's modulus, and toughness, respectively, for the highest performing BNNTs/PVA fibers produced from dispersions containing as low as 0.1 mass% of nanotube concentration. Among the coagulation solvents tested, we found that solvents with higher polarity such as methanol and ethanol generally produced fibers with improved mechanical properties, where the fiber toughness shows a strong correlation with solvent polarity. These findings provide insights into assembling BNNTs-based fibers with improved mechanical properties for developing unique applications.