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Abstract Polymer single crystals are used as templates to synthesize polymer brushes, known as the “polymer‐single‐crystal‐assisted‐grafting‐to” (PSCAGT) approach. Polymer brushes with controlled grafting densities and spatial tethering locations are demonstrated. Previous works focused on solution crystallization, which involves large amounts of organic solvent, and the grafting density can only be tuned by varying crystallization temperatures. In this work, thin film crystallization is utilized to fabricate 2D polymer crystals on flat surfaces. Subsequent chemical tethering leads to polymer brushes that retain the original morphology of the crystals with high fidelity. Furthermore, it is shown that the grafting density of the polymer brushes fabricated using this method depends on the chain end distribution on the top/bottom surfaces of the crystal, which can be facilely controlled by annealing the crystals at various nonsolvent media. This work broadens the scope of the PSCAGT method and provides a new route to achieve polymer brushes with controlled structures. 

Abstract Nanoparticle (NP) assembly has been extensively studied, and a library of NP superstructures has been synthesized. These intricate structures show unique collective optical, electronic, and magnetic properties. In this work, we report a bottom‐up approach for fabricating spherical gold nanoparticle (AuNP) assemblies that mimic colloidosomes. Co‐crystallization of lipoic acid‐end‐functionalized poly(ethylene oxide) (PEO) and AuNPs in solution via a self‐seeding method led to the formation of hollow spherical NP assemblies named nanoparticle crystalsomes (NPCs). Due to the spherical shape, the translational symmetry of PEO crystals is broken in NPCs, which can be attributed to the competition between NP close packing and polymer crystallization. This was confirmed by tuning the NPC morphology via varying the self‐seeding temperature, crystallization temperature, and PEO molecular weight. We envisage that this strategy paves the way to attaining exquisite morphological control of NP assemblies with broken translational symmetry. 

Abstract Block copolymer brushes are of great interest due to their rich phase behavior and value‐added properties compared to homopolymer brushes. Traditional synthesis involves grafting‐to and grafting‐from methods. In this work, a recently developed “polymer‐single‐crystal‐assisted‐grafting‐to” method is applied for the preparation of block copolymer brushes on flat glass surfaces. Triblock copolymer poly(ethylene oxide)‐b‐poly(l‐lactide)‐b‐poly(3‐(triethoxysilyl)propyl methacrylate) (PEO‐b‐PLLA‐b‐PTESPMA) is synthesized with PLLA as the brush morphology‐directing component and PTESPMA as the anchoring block. PEO‐b‐PLLA block copolymer brushes are obtained by chemical grafting of the triblock copolymer single crystals onto a glass surface. The tethering point and overall brush pattern are determined by the single crystal morphology. The grafting density is calculated to be ≈0.36 nm⁻²from the atomic force microscopy results and is consistent with the theoretic calculation based on the PLLA crystalline lattice. This work provides a new strategy to synthesize well‐defined block copolymer brushes. 

Abstract In recent decades, extensive studies have been devoted to assembling nanoparticles (NPs) into various ordered structures to achieve novel optical properties. However, it still remains a challenging task to assemble NPs into cyclic one‐dimensional (1D) shapes, such as rings and frames. Herein, we report a directed assembly method to precisely assemble NPs into well‐defined, free‐standing frames using polymer single crystals (PSCs) as the template. Preformed poly(ethylene oxide) (PEO) single crystals were used as the template to direct the crystallization of block copolymer (BCP) poly(ethylene oxide)‐b‐poly(4‐vinylpyridine) (PEO‐b‐P4VP), which directs the gold NPs (AuNPs) to form AuNP frames. By controlling the PSC growth, we were able to, for the first time, precisely tune both the size and width of the AuNP frame. These novel AuNP frames topologically resemble NP nanorings and cyclic polymer chains, and show unique surface plasmon resonance (SPR) behaviors.