Production of Organizational Chiral Structures by Design.

Organizational chirality on surfaces has been of interest in chemistry and materials science due to its scientific importance as well as its potential applications. Current methods for producing organizational chiral structures on surfaces are primarily based upon the self-assembly of molecules. While powerful, the chiral structures are restricted to those dictated by surface reaction thermodynamics.

Nanoscale Raman Characterization of a 2D Semiconductor Lateral Heterostructure Interface.

The nature of the interface in lateral heterostructures of 2D monolayer semiconductors including its composition, size, and heterogeneity critically impacts the functionalities it engenders on the 2D system for next-generation optoelectronics. Here, we use tip-enhanced Raman scattering (TERS) to characterize the interface in a single-layer MoS/WS lateral heterostructure with a spatial resolution of 50 nm. Resonant and nonresonant TERS spectroscopies reveal that the interface is alloyed with a size that varies over an order of magnitude─from 50 to 600 nm─within a single crystallite.

Spatially Selective and Density-Controlled Activation of Interfacial Mechanophores.

Mechanically sensitive molecules known as mechanophores have recently attracted much interest due to the need for mechanoresponsive materials. Maleimide-anthracene mechanophores located at the interface between poly(glycidyl methacrylate) (PGMA) polymer brushes and Si wafer surfaces were activated locally using atomic force microscopy (AFM) probes to deliver mechanical stimulation. Each individual maleimide-anthracene mechanophore exhibits binary behavior: undergoing a retro-[4 + 2] cycloaddition reaction under high load to form a surface-bound anthracene moiety and free PGMA or remaining unchanged if the load falls below the activation threshold.