Nanostructured Bimetallic Block Copolymers as Precursors to Magnetic FePt Nanoparticles

Phase-separated block copolymers (BCPs) that function as precursors to arrays of FePt nanoparticles (NPs) are of potential interest for the creation of media for the next-generation high-density magnetic data storage devices. A series of bimetallic BCPs has been synthesized by incorporating a complex containing Fe and Pt centers into the coordinating block of four different poly­(styrene-<i>b</i>-4-vinylpyridine)­s (PS-<i>b</i>-P4VPs, <b>P1–P4</b>). To facilitate phase separation for the resulting metalated BCPs (<b>PM1–PM4</b>), a loading of the FePt-bimetallic complex corresponding to ca. 20% was used. The bulk and thin-film self-assembly of these BCPs was studied by transmission electron microscopy (TEM) and atomic force microscopy, respectively. The spherical and cylindrical morphologies observed for the metalated BCPs corresponded to those observed for the metal-free BCPs. The products from the pyrolysis of the BCPs in bulk were also characterized by TEM, powder X-ray diffraction, and energy-dispersive X-ray spectroscopy, which indicated that the FePt NPs formed exist in an fct phase with average particle sizes of ca. 4–8 nm within a carbonaceous matrix. A comparison of the pyrolysis behavior of the metalated BCP (<b>PM3</b>), the metalated <b>P4VP</b> homopolymer (<b>PM5</b>), and the molecular model organometallic complex revealed the importance of using a nanostructured BCP approach for the synthesis of ferromagnetic FePt NPs with a smaller average NP size and a close to 1:1 Fe/Pt stoichiometric ratio

Patterning of L10 FePt Nanoparticles with Ultra-High Coercivity for Bit-Patterned Media

L1(0)-ordered FePt nanoparticles (NPs) with ultra-high coercivity were directly prepared from a new metallopolyyne using a one-step pyrolysis method. The chemical ordering, morphology and magnetic properties of the as-synthesized FePt NPs have been studied. Magnetic measurements show the coercivity of these FePt NPs is as high as 3.6 T. Comparison of NPs synthesized under the Ar and Ar/H-2 atmospheres shows that the presence of H-2 in the annealing environment influences the nucleation and promotes the growth of L1(0)-FePt NPs. Application of this metallopolymer for bit-patterned media was also demonstrated using nanoimprint lithography.Department of Applied PhysicsDepartment of Applied Biology and Chemical Technolog

Genome-wide identification and expression analysis of the CHYR gene family in Phaseolus vulgaris under abiotic stress at the seeding stage

ABSTRACTReally Interesting New Gene (RING) proteins are referred to as CHY zinc and ring finger protein (CHYR) members because they have the CHY domain, a type of protein that responds to abiotic stress. However, there are scant data on CHYR members in Phaseolus vulgaris (common bean). This study identified eight CHYR members (PvCHYRs) in the reference genome. A comprehensive analysis was performed to determine function, location, basic information, evolution, motifs, gene structure, cis-acting elements, collinearity, and expression patterns at the seeding stage. The results demonstrated that PvCHYRs might be involved in response to abiotic stressors, whereas some PvCHYRs were screened and can be used as candidate CHYR genes in further research. This study provides a basis for identifying and analyzing PvCHYR members and provides insights for their screening in future research

A gated strategy stabilizes room‐temperature phosphorescence

Abstract Room‐temperature phosphorescence (RTP) of purely organic materials is easily quenched with unexpected purposes because the excited triplet state is extremely susceptible to external stimuli. How to stabilize the RTP property of purely organic luminogens is still challenging and considered as the bottleneck in the further advancement of the bottom‐up approach. Here, we describe a gated strategy that can effectively harness RTP by employing complexation/dissociation with proton. Due to the order‐disorder transition orientation of intermolecular packing, the RTP of organic molecules 2,4,6‐tris(4′‐bromo‐[1,1′‐biphenyl]‐4‐yl)‐1,3,5‐triazine (Br‐TRZ) will easily vanish upon mechanical force. Impressively, by enhancing its intramolecular charge transfer effect, the protonated Br‐TRZ stubbornly possesses an obvious RTP under external grinding, whatever in the ordered or disordered intermolecular arrangement state. Consequently, the “Lock” gate of RTP was achieved in the protonated Br‐TRZ molecule. Combined with theoretical calculation analysis, the enhanced charge transfer effect can narrow the singlet−triplet energy gap significantly, and stabilize the RTP property of triazine derivative sequentially. Furthermore, the locked RTP can be tuned via proton and counterions repeatedly and show excellent reversibility. This gated RTP concept provides an effective strategy for stabilizing the RTP emission of purely organic systems