Hierarchical Fullerene Assembly: Seeded Coprecipitation and Electric Field Directed Assembly

Hierarchical C₆₀ colloidal films are assembled from nanoscale to macroscale. Fullerene molecular crystals are grown via seeded cosolvent precipitation with mixed solvent [tetrahydronaphthalene (THN)/trimethylpyridine (TMP)] and antisolvent 2‐propanol. The fullerene solutions are aged under illumination, which due to the presence of TMP reduces the free monomer concentration through fullerene aggregation into nanoparticles. The nanoparticles seed the growth of monodisperse fullerene colloids on injection into the antisolvent. Diverse colloidal morphologies are prepared as a function of injection volume and fullerene solution concentration. The high fullerene solubility of THN enables C₆₀ colloids to be prepared in quantities sufficient for assembly (5 × 10⁸). Electric fields are applied to colloidal C₆₀ platelets confined to two dimensions. The particles assemble under dipolar forces, dielectrophoretic forces, and electrohydrodynamic flows. Frequency‐dependent phase transitions occur at the critical Maxwell–Wagner crossover frequency, where the effective polarizability of the particles in the medium is substantially reduced. Structures form as a function of field strength, frequency, and confinement including hexagonal, oblique, string fluid, coexistent hexagonal‐rhombic, and tetratic.     

Mitigation of Amyloidosis with Nanomaterials

Amyloidosis is a biophysical phenomenon of protein aggregation with biological and pathogenic implications. Among the various strategies developed to date, nanomaterials and multifunctional nanocomposites possessing certain structural and physicochemical traits are promising candidates for mitigating amyloidosis in vitro and in vivo. The mechanisms underpinning protein aggregation and toxicity are introduced, and opportunities in materials science to drive this interdisciplinary field forward are highlighted. Advancement of this emerging frontier hinges on exploitation of protein self-assembly and interactions of amyloid proteins with nanoparticles, intracellular and extracellular proteins, chaperones, membranes, organelles, and biometals.     

水溶性TiO2离子液体纳米杂化材料的制备与应用

TiO₂纳米颗粒具有较强的氧化性, 作为光催化剂, 可以在阳光照射下减少或消除有机污染物。为提高TiO₂纳米颗粒分散性和溶解性, 研究其在不同领域, 特别是环境保护领域的应用, 本实验室用两步法制备得到黄色透明的水溶性TiO₂离子液体纳米杂化材料。在这个杂化体系中,有机磺酸基团作为冠层可以提供“自溶剂”成为TiO₂纳米粒子的分散体。分散实验表明：TiO₂离子液体纳米杂化材料表面的水溶性有机物在水中具有良好的溶解性, 容易去除, 可应用于家居装饰表面。光催化降解甲醛的研究表明：TiO₂离子液体纳米杂化流体具有良好的光催化性能。水溶性TiO₂离子液体纳米杂化材料有望成为未来环境保护的发展方向。     

Effective Light Directed Assembly of Building Blocks with Microscale Control

Light‐directed forces have been widely used to pattern micro/nanoscale objects with precise control, forming functional assemblies. However, a substantial laser intensity is required to generate sufficient optical gradient forces to move a small object in a certain direction, causing limited throughput for applications. A high‐throughput light‐directed assembly is demonstrated as a printing technology by introducing gold nanorods to induce thermal convection flows that move microparticles (diameter = 40 µm to several hundreds of micrometers) to specific light‐guided locations, forming desired patterns. With the advantage of effective light‐directed assembly, the microfluidic‐fabricated monodispersed biocompatible microparticles are used as building blocks to construct a structured assembly (≈10 cm scale) in ≈2 min. The control with microscale precision is approached by changing the size of the laser light spot. After crosslinking assembly of building blocks, a novel soft material with wanted pattern is approached. To demonstrate its application, the mesenchymal stem‐cell‐seeded hydrogel microparticles are prepared as functional building blocks to construct scaffold‐free tissues with desired structures. This light‐directed fabrication method can be applied to integrate different building units, enabling the bottom‐up formation of materials with precise control over their internal structure for bioprinting, tissue engineering, and advanced manufacturing.     

Assembly and Electronic Applications of Colloidal Nanomaterials

Artificial solids and thin films assembled from colloidal nanomaterials give rise to versatile properties that can be exploited in a range of technologies. In particular, solution‐based processes allow for the large‐scale and low‐cost production of nanoelectronics on rigid or mechanically flexible substrates. To achieve this goal, several processing steps require careful consideration, including nanomaterial synthesis or exfoliation, purification, separation, assembly, hybrid integration, and device testing. Using a ubiquitous electronic device – the field‐effect transistor – as a platform, colloidal nanomaterials in three electronic material categories are reviewed systematically: semiconductors, conductors, and dielectrics. The resulting comparative analysis reveals promising opportunities and remaining challenges for colloidal nanomaterials in electronic applications, thereby providing a roadmap for future research and development.     

Controlled Fabrication of Micropatterned Supramolecular Gels by Directed Self‐Assembly of Small Molecular Gelators

Herein, the micropatterning of supramolecular gels with oriented growth direction and controllable spatial dimensions by directing the self‐assembly of small molecular gelators is reported. This process is associated with an acid‐catalyzed formation of gelators from two soluble precursor molecules. To control the localized formation and self‐assembly of gelators, micropatterned poly(acrylic acid) (PAA) brushes are employed to create a local and controllable acidic environment. The results show that the gel formation can be well confined in the catalytic surface plane with dimensions ranging from micro‐ to centimeter. Furthermore, the gels show a preferential growth along the normal direction of the catalytic surface, and the thickness of the resultant gel patterns can be easily controlled by tuning the grafting density of PAA brushes. This work shows an effective “bottom‐up” strategy toward control over the spatial organization of materials and is expected to find promising applications in, e.g., microelectronics, tissue engineering, and biomedicine.     

Directed Assembly of Gold Nanorods by Terminal‐Base Pairing of Surface‐Grafted DNA

Directed assemblies of anisotropic metal nanoparticles exhibit attractive physical and chemical properties. However, an effective methodology to prepare differently directed assemblies from the same anisotropic nanoparticles is not yet available. Gold nanorods (AuNRs) region‐selectively modified with different DNA strands can form side‐by‐side (SBS) and end‐to‐end (ETE) assemblies in a non‐crosslinking manner. When the complementary DNA is hybridized to the surface‐bound DNA, stacking interaction between the blunt ends takes place in the designated regions. Such AuNRs assemble into highly ordered structures, assisted by capillary forces emerging on the substrate surface. Moreover, insertion of a mercury(II)‐mediated thymine–thymine base pair into the periphery of the DNA layer allows selective formation of the SBS or ETE assemblies from the strictly identical AuNRs with or without mercury(II).     

Rational Design of MOF-Based Hybrid Nanomaterials for Directly Harvesting Electric Energy from Water Evaporation

The continuous exploration of clean-energy technology is critical for the sustainable development of society. The recent work on the electric energy harvesting from water evaporation has made a significant contribution to the utilization of clean energy for self-powering systems. Here, a novel metal–organic-framework-based hybrid nanomaterial is delicately designed and synthesized by the growth of UIO-66 nanoparticles on 2D AlOOH nanoflakes. Due to the combined merits from the 2D morphology, which is inherited from the AlOOH nanoflakes, and the high surface potential, which originates from the UIO-66 nanoparticles, the device made of the AlOOH/UIO-66 hybrid nanomaterials can harvest electric energy from natural water evaporation. An open-circuit voltage of 1.63 ± 0.10 V can be achieved on the prototype devices made of the hybrid nanomaterial. As a proof-of-concept application, a small electric appliance, e.g., a digital calculator, is powered up by a 3 × 3 device array connected in a combined series–parallel configuration.     

25th Anniversary Article: Hybrid Nanostructures Based on Two‐Dimensional Nanomaterials

Two‐dimensional (2D) nanomaterials, such as graphene and transition metal dichalcogenides (TMDs), receive a lot of attention, because of their intriguing properties and wide applications in catalysis, energy‐storage devices, electronics, optoelectronics, and so on. To further enhance the performance of their application, these 2D nanomaterials are hybridized with other functional nanostructures. In this review, the latest studies of 2D nanomaterial‐based hybrid nanostructures are discussed, focusing on their preparation methods, properties, and applications.