High χ P2PFBEMA-b-P2VP Block Copolymers Forming 6-8 nm Domains for Semiconductor Lithography

We leveraged the potential of high χ-low N block copolymer (BCP), namely, poly[2-(perfluorobutyl) ethyl methacrylate]-block-poly(2-vinylpyridine) (P2PFBEMA-b-P2VP), and demonstrated its utility in next-generation nanomanufacturing. By combining molecular dynamics simulations with experiments, the χ value was calculated to be as high as 0.4 (at 150 °C), surpassing similar structures. Highly ordered features suitable for application were observed, ranging in periods from 19.0 nm down to 12.1 nm, with feature sizes as small as 6 nm. Transmission electron microscopy images of the BCP solutions indicated that preformed micelles in the solution facilitated the self-assembly process of the thin film. In addition, the vertical or parallel orientation of the cylindrical structure was determined by manipulating the solvent, substrate, and annealing conditions. Finally, guided by a wide topographical template, nearly defect-free directed self-assembly (DSA) lines with a resolution of 8 nm were achieved, highlighting its potential practical application in DSA lithography technology.

A Star-Structured Polymer Electrolyte for Low-Temperature Solid-State Lithium Batteries

Solid-state polymer lithium metal batteries (SSLMBs) have attracted considerable attention because of their excellent safety and high energy density. However, the application of SSLMBs is significantly impeded by uneven Li deposition at the interface between solid-state electrolytes and lithium metal anode, especially at a low temperature. Herein, this issue is addressed by designing an agarose-based solid polymer electrolyte containing branched structure. The star-structured polymer is synthesized by grafting poly (ethylene glycol) monomethyl-ether methacrylate and lithium 2-acrylamido-2-methylpropanesulfonate onto tannic acid. The star structure regulates Li-ion flux in the bulk of the electrolyte and at the electrolyte/electrode interfaces. This unique omnidirectional Li-ion transportation effectively improves ionic conductivity, facilitates a uniform Li-ion flux, inhibits Li dendrite growth, and alleviates polarization. As a result, a solid-state LiFePO4||Li battery with the electrolyte exhibits outstanding cyclability with a specific capacity of 134 mAh g-1 at 0.5C after 800 cycles. The battery shows a high discharge capacity of 145 mAh g-1 at 0.1 C after 200 cycles, even at 0 °C. The study offers a promising strategy to address the uneven Li deposition at the solid-state electrolyte/electrode interface, which has potential applications in long-life solid-state lithium metal batteries at a low temperature.

Using GISAXS to Detect Correlations between the Locations of Gold Particles Electrodeposited from an Aqueous Solution

Electrodeposition is a powerful tool for the bottom-up fabrication of novel electronic devices. This necessitates a complete understanding of the deposition process beyond the classical description using current transients. Recent calculations predict deviations within the spatial arrangement of electrodeposited particles, away from random nucleation. The spatial arrangement of Au particles generated through aqueous electrodeposition on a nontemplated substrate is investigated by grazing incidence small-angle X-ray scattering (GISAXS). We show that GISAXS is able to reveal spatial correlations within deposited particles that are not easily detectable by microscopy.

Semi-crystalline polymethylene-b-poly(acrylic acid) diblock copolymers: aggregation behavior, confined crystallization and controlled growth of semicrystalline micelles from dilute DMF solution

In this paper, we have systematically investigated the aggregation behavior, confined crystallization and controlled growth of a novel polyolefin analogue-containing block copolymers (BCPs), i.e., polymethylene-b-poly(acrylic acid) diblock copolymers (PM-b-PAA). On cooling from a homogenous DMF solution at 80 °C, PM-b-PAA was found to crystallize and aggregate with well-defined disk-like micelles. The aggregate behavior and in-plane morphology of PM-b-PAA could be easily controlled by modifying the block ratio, solution pH and solvent composition (DMF-water), by manipulating the crystallization of PM block and the stretching degree of solvated PAA corona. Further investigation of the crystalline feature of PM-b-PAA indicated that the crystallization of PM was retarded by tethered amorphous PAA segments. The crystalline micelle could construct a nano-confined environment with PM folding as the core into a thickness of the mono-layered polyethylene. Finally, when cultured in dilute DMF solution at 50 °C, the initial crystalline micelles, being as self-seeds, could follow a living growth mechanism and develop into single crystals, with well-defined lozenge-shaped morphology.