ACS Macro Letters最新文献

Charged-neutral polymer blends, wherein an ion-containing polymer is blended with a neutral polymer, are potential candidates for battery electrolytes due to their improved ion transport properties and electrochemical stability. Though electrostatic interactions in charged polymer blends can theoretically stabilize ordered nanostructures analogous to those observed in neutral block copolymers, direct experimental evidence remains limited. Here, we investigate the effects of divalent cation identity on the nanoscale morphology of charged-neutral polymer blends composed of poly(ethylene oxide) (PEO) and Mg²⁺ or Ca²⁺ ion-containing polymers, poly[3-(methylacryloxy)propylsulfonyl-1-(trifluoromethanesulfonylimide)] (P(Mg(MTFSI)₂) or P(Ca(MTFSI)₂). By tuning the size of the divalent counterion, we are able to precisely tune the ion solvation between the free cation and PEO, which acts as a solvent in this system. Differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) measurements reveal that Mg²⁺ and Ca²⁺ ions induce distinct structural behavior. In both systems, the blends become more miscible as the concentration of ion-containing polymer is increased indicated by increased suppression of PEO crystallinity. At the highest concentrations of P(Mg(MTFSI)₂), the blends undergo microphase separation and generate nanostructures with short-ranged ordering. In contrast, calcium ions, which are more readily solvated by PEO, produce more homogeneous blends characterized by a single glass-transition temperature and featureless SAXS data. The results demonstrate the novel experimental confirmation that charged-neutral polymer blends can undergo microphase separation and show that counterion identity can be exploited as a design parameter to control nanoscale morphology.

Cyano-substituted oligo(p-phenylenevinylene) derivatives (cyano-OPVs) demonstrate superior photophysical properties in solution with photoluminescence quantum yield (PLQY) of up to 87% yet experience severe aggregation-caused quenching in the solid state (PLQY typically 20%–40%), fundamentally limiting their practical implementation in optoelectronic devices. Here, we present a novel approach to enhancing the solid-state PLQY of cyano-OPVs by harnessing polymer crystallization through supramolecular interactions. We designed and synthesized a 2-ureido-4[1H]-pyrimidinone (UPy)-functionalized cyano-OPV derivative (UPy-OPV-UPy) and incorporated it into a crystallizable UPy-terminated poly(butylene succinate) (PBS-UPy) matrix. Systematic investigation of the photophysical properties and isothermal crystallization kinetics of PBS-UPy/UPy-OPV-UPy blends revealed a remarkable solid-state PLQY of approximately 97%, surpassing both traditional solid-state fluorescent materials and solution-state performance. This unprecedented enhancement is attributed to the effect of crystallization-driven supramolecular reorganization, which disrupts unfavorable fluorophore aggregates. This nondestructive approach offers a new paradigm for designing high-performance solid-state emissive materials, potentially overcoming the persistent challenge of aggregation-caused quenching that typically limits solid-state fluorescent material performance.

Neoantigens are promising candidates for personalized cancer vaccines and immunotherapies. However, low immunogenicity and insufficient cross-presentation of neoantigens remain a major challenge. Inspired by natural glycocalyx and its important functions in immune response, here we report a glycocalyx-mimicking nanovehicle constructed from (oligo)mannoside-modified acid-sensitive glycopolymers to improve the efficiency of tumor neoantigens. These amphiphilic glycopolymers assembled into nanoparticles could serve as immune activators for dendritic cells maturation. The encapsulation of neoantigens in the glycopolymer nanocarrier improves the physicochemical properties and endosomal escape of the antigens, thereby not only enhancing their uptake and cross-presentation by dendritic cells but also promoting cytotoxic T cell proliferation and proinflammatory cytokine secretion. These results indicated that the glycocalyx-mimicking nanovehicle integrating delivery and immune adjuvant functions provides a promising platform for cancer vaccines.

Stimuli-responsive block copolymer (BCP) particles offer a promising platform for tunable photonic materials; however, most structural transformations originate from uniform lamellar templates that reorganize only under strong thermal or solvent-mediated activation. Here, we report a distinct pH-driven chain reorganization behavior in partially quaternized poly(styrene-block-2-vinylpyridine) (PS-b-P2VP) microparticles that initially possess heterogeneous internal morphologies, comprising PS-encapsulated P2VP domains and stacked lamellar domains. Upon acid exposure, protonation of unquaternized P2VP establishes a hydration-induced swelling gradient: less-constrained lamellae laterally expand and redistribute along interfaces, whereas PS-encapsulated lamellar regions act as rigid anchors. This anisotropic response progressively redistributes chain stress and solvation, transforming the stacked lamellae into an irregular, laterally dilated morphology with thin, hydrated P2VP layers. This progressive chain reorganization gives rise to a steady blue-shift in structural color from 622 to 478 nm, in line with the gradual contraction of domain periodicity. These findings reveal that structural heterogeneity can serve as an intrinsic driving force for topological reconstruction in vitrified BCP particles, enabling programmable, history-dependent photonic responses under mild aqueous conditions.

Spider silk spinning begins with coacervation into a dense protein phase that organizes into liquid crystalline domains. Changes in salt concentration, together with shear forces, then direct the alignment needed to form highly ordered fibers. Inspired by this process, we developed a fully synthetic system of liquid crystalline complex coacervates designed to replicate the hierarchical organization and alignment mechanisms of spider silk, focusing on processing pathways. We show that salt concentration (tetrabutylammonium bromide, TBAB) governs the balance between isotropic and liquid crystalline states, with coacervation suppressed above 0.5 M, smectic order stabilized at ≤0.2 M, and isotropic chain networks prevailing at intermediate concentrations. Crucially, the degree of shear alignment depends strongly on salt: higher salt concentrations accelerate molecular relaxation and raise the threshold shear rate required to induce ordering, echoing the cooperative role of the ion composition and shear in natural silk spinning. Rheological and X-ray scattering measurements confirm that this salt–shear interplay dictates both the viscoelastic response and the molecular anisotropy. Finally, we demonstrate directional alignment through stretching and extrusion-based 3D printing and show that the unique tunability of salt concentration provides direct control over both processability and shear-induced alignment, offering a powerful biomimetic route to anisotropic material design.