Hui Sun

Functional materials with circularly polarized luminescence (CPL) property featuring both high luminescence efficiency and strong chiroptical activity are highly desirable for advanced photonic applications such as three-dimensional displays, optical encryption, asymmetric photochemistry, and biomedical imaging, yet remain challenging to develop. While extensive efforts have focused on engineering chromophore structures and chiral building blocks, the influence of the spacer connecting luminophores and chiral scaffolds on CPL generation remains poorly understood. Herein, we report an alkylene spacer engineering strategy to regulate supramolecular chirality and CPL performance in homopolypeptide-based assemblies. A series of luminescent homopolypeptides were synthesized, bearing an achiral terminal luminophore connected to the backbone through alkylene spacers of varying lengths. By self-assembly, nanotoroid-dispersed aqueous solutions were obtained from these homopolypeptides with photoluminescence quantum yields exceeding 50%. Despite their nearly identical morphologies, the assemblies exhibited markedly different CPL activities. Increasing the spacer length led to continuous enhancement of CPL performance, with the luminescence dissymmetry factor (glum) increasing by an order of magnitude from 1.1 × 10–3 to 1.1 × 10–2. Structural characterization and molecular simulations reveal that spacer elongation strengthens the coupling between the terminal luminophore and helical polypeptide scaffold, facilitating more efficient chirality transfer and supramolecular chirality amplification within the toroidal assemblies. Further optimizing the degree of polymerization promotes supramolecular ordering and amplifies CPL activity, yielding an enhanced glum up to 1. 8 × 10–2. This work reveals a previously overlooked role of spacer-mediated chirality communication between the terminal luminophore and helical polypeptide scaffolds and establishes alkylene spacer length as a critical structural parameter for chirality amplification in this supramolecular CPL system, providing new insights into the “molecular structure – supramolecular assembly – chiroptical property” relationship.

Viruses typically possess spike-like surface structures that play pivotal roles in their biological functions, including host cell invasion and signal transduction. Despite the structural advantages of virus-like architectures, the controlled fabrication of artificial virus-like nanoparticles (VNPs) remains a significant challenge. Herein, a series of amphiphilic glycopolymers are designed and synthesized to self-assemble into VNPs with controlled tentacles on their surfaces. As the initial concentration increases, the morphology of the assemblies gradually evolves from spherical nanoparticles to virus-like nanostructures with an increased number and length of the tentacles. The existence of glucose moieties is crucial for driving this morphological transformation owing to their strong hydrogen-bonding interactions and ultrahydrophilicity. Monitoring the formation process of the VNPs, we found that spherical nanoparticles were formed at the early stage of self-assembly. With an increasing water content, the nanoparticles gradually deform and develop surface wrinkles, followed by the emergence and elongation of tentacles upon further water addition, leading to the formation of VNPs, which exhibit morphology-promoted and glucose transporter 1-mediated endocytosis. These findings highlight the significance of glycosyl groups in promoting the formation of VNPs and provide fresh insights into the controlled preparation of artificial biomimetic nanomaterials with precise structures and tailored functionalities.

Rapid industrialization has led to the massive release of dye pollutants, posing a significant risk to aquatic ecosystems and human health. Polymeric nanosheets are highly attractive candidates for water remediation due to their abundant, accessible active sites. Herein, an intramolecular cyclization-induced self-assembly (ICISA) strategy is employed to construct polymeric nanosheets on the basis of reactivity of an amphiphilic poly(amic acid) (PAA) for rapid cationic dye adsorption. Upon thermal annealing, an intramolecular cyclization reaction occurs to generate polyimide (PI) segments in the polymer backbone, affording poly(amic acid-stat-imide) (P(AA-stat-I)), which enhances polymer solvophobicity and crystallinity, inducing ICISA of P(AA-stat-I) and leading to the formation of nanosheets. Benefiting from their multilayered structure and rich functional groups of carboxyl and amide, the nanosheets demonstrate ultrafast and efficient adsorption toward Victoria Blue R in water, with over 92.90% removal achieved in only 2 min and an adsorption capacity of up to 188.98 mg g–1. Mechanistic investigations reveal that the adsorption process is driven synergistically by electrostatic interaction, hydrogen bonding, and π–π stacking. This study employs an ICISA strategy for the versatile fabrication of polymeric nanosheets for high-performance adsorption of cationic dyes.

Despite more than a decade of development, inverse vulcanization continues to produce sulfur-rich polymers with limited solubility, which impedes definitive structural characterization by solution-based techniques. The dominant hypothesis proposes that these materials form a cross-linked network. However, recent work by Pyun and co-workers demonstrated the coexistance of cross-linked and linear structures for the direct synthesis of vulcanized 1,3-diisopropenylbenzene (DIB) fragments by employing solid-state/solution nuclear magnetic resonance (NMR) and AlLiH4 reductive degradation of poly(S-DIB). To enable unambiguous structural elucidation, we employ selenium disulfide (SeS₂) as the sulfur source, which retains the eight-membered ring structure of S₈ but features a lower bond dissociation energy. The current protocol yields soluble sulfur/selenium-rich polymers. Structural characterization confirms the coexistence of linear and cross-linked components for the resultant polymers. The exceptional solubility enables comprehensive gel permeation chromatography (GPC) analysis. All polymers, synthesized at varying feed ratios, exhibit ultrahigh molecular weights (Mn > 1,300,000 g/mol). Additionally, poly(SeS2-DIB) synthesized with various feed ratios was comprehensively characterized using 1H NMR, FT-IR, PXRD, TGA, DSC, EA, and SEM to elucidate its structure and properties. This provides a critical foundation for investigating sulfur sequence length and degradation pathways.

Presented in this study is an intramolecular cyclization reaction-induced self-assembly strategy for the facile preparation of porous elliptical capsules, enabling pH-independent removal of methylene blue through multiple non-covalent interactions.

Bottle‐shaped nanoparticles, comprising a long neck and a large single interior cavity, have been drawing extensive attention due to their unique structural characteristics, exhibiting significant potential in catalysis, drug delivery and nanomotors. In this study, a polymer self‐assembly strategy is proposed to prepare bottle‐shaped nanoparticles with controlled cavity and neck dimensions based on a triphenylamine‐functionalized amphiphilic alternating copolymer of poly(amic acid) (PAA). By adjusting the initial concentration and water dropping rate during self‐assembly, the cavity diameter and neck length of the bottle‐shaped nanoparticles can be well controlled. Once the PAA is annealed at 160, 180 and 220°C, respectively, hydrophobic and rigid polyimide segments are generated in the backbone of the polymer, leading to a shape transformation from bottle‐shaped nanoparticles to porous capsules and pod‐shaped nanoparticles, as well as a significant red shift and enhancement of the fluorescence. Exploring the formation mechanism of bottle‐shaped nanoparticles, a protrusion is formed at the early stage of the self‐assembly due to the build‐up of osmotic pressure, which extends with the addition of water to afford bottle‐shaped nanoparticles. Overall, the controlled preparation of bottle‐shaped nanoparticles with adjustable cavity and neck is achieved, opening up new avenues for the controlled construction of highly anisotropic nanostructures.