Cylindrical polymer micelles pack in 3D: When you control chemistry, solvents, temperature, and concentration, surfactants and block copolymers will readily assemble into micelles, rods, and other structures. Qiu et al. take this to new lengths through precise selection of longer polymer blocks that self-assemble through a crystallization process (see the Perspective by Lee et al. ). They chose polymer blocks that were either hydrophobic or polar and used miscible solvents that were each ideal for only one of the blocks. Their triblock comicelles generated a wide variety of stable three-dimensional superstructures through side-by-side stacking and end-to-end intermicellar association. Science , this issue p. 1329 ; see also p. 1310

Growing patterned rectangular objects: The growth of patterned objects usually requires a template to aid the positioning of multiple materials. Qiu et al. used the seeded growth of a crystallizable block copolymer and a homopolymer to produce highly uniform rectangular structures (see the Perspective by Ballauff). Chemical etching, or dissolution, of uncross-linked regions of the rectangular structures produced perforated platelet micelles. The sequential addition of different blends and cross-linking/dissolution strategies allowed the formation of well-defined hollow rectangular micelles, which can be functionalized in a variety of ways. Science , this issue p. 697 ; see also p. 656

The use of crystallization as a tool to control the self-assembly of polymeric and molecular amphiphiles in solution is attracting growing attention for the creation of non-spherical nanoparticles and more complex, hierarchical assemblies. In particular, the seeded growth method termed living crystallization-driven self-assembly (CDSA) has been established as an ambient temperature and potentially scalable platform for the preparation of low dispersity samples of core–shell fiber-like or platelet micellar nanoparticles. Significantly, this method permits predictable control of size, and access to branched and segmented structures where functionality is spatially-defined. Living CDSA operates under kinetic control and shows many analogies with living chain-growth polymerizations of molecular organic monomers that afford well-defined covalent polymers of controlled length except that it covers a much longer length scale (ca. 20 nm to 10 μm). The method has been applied to a rapidly expanding range of crystallizable polymeric amphiphiles, which includes block copolymers and charge-capped homopolymers, to form assemblies with crystalline cores and solvated coronas. Living CDSA seeded growth methods have also been transposed to a wide variety of π-stacking and hydrogen-bonding molecular species that form supramolecular polymers in processes termed “living supramolecular polymerizations”. In this article we outline the main features of the living CDSA method and then survey the promising emerging applications for the resulting nanoparticles in fields such as nanomedicine, colloid stabilization, catalysis, optoelectronics, information storage, and surface functionalization.

Ultralong room‐temperature phosphorescence (RTP) is highly useful for information encryption, organic electronics, bioelectronics, etc. However, the preparation of related metal‐free materials with multiple colors across the full spectrum remains a major challenge. Herein, a facile method is developed to fabricate boron‐doped carbon dot (B‐CD) composites with full‐color long lifetime RTP continuously tailorable in the range of 466–638 nm simply by pyrolysis of the citric acid and boric acid precursors with various mass ratios at different temperatures. This leads to the formation of luminescent B‐CD centers in a rigid polycrystalline B₂O₃ matrix, which effectively stabilizes the triplet excited states of B‐CDs. Thus, the composites become phosphorescent over a relatively long period (5–12 s) after the removal of the irradiation source. Meanwhile, the increased particle size and oxidation degree of B‐CDs obtained at larger citric acid feeding or higher pyrolysis temperature continuously shift the phosphorescence from blue to red. Due to the formation of multiple luminescence centers, the RTP can also be finely modulated by the excitation wavelength. The resulting B‐CD composites with highly tunable long lifetime RTP further allow a variety of distinctive applications in multidimensional encryption handily utilizing space, time, and color variations.

N₂-plasma bombardment allows the large-area fabrication of high 1T phase N,Pt-doped MoS₂ nanosheets with prominent alkaline HER activity.