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In this study, two dithieno[3,2-b]thiophenecyclopentacarbazole (DTTC)-based nonfullerene acceptors (NFAs) named DTTC-4F-C8 and DTTC-4Cl-C9 are designed, synthesized, and incorporated as the second ...

Surface properties are essential for substrates exhibiting high sensitivity in surface-enhanced Raman scattering (SERS) applications. In this work, novel SERS hybrid substrates using polystyrene-block-poly(methyl methacrylate) and anodic aluminum oxide templates is presented. The hybrid substrates not only possess hierarchical porous nanostructures but also exhibit superhydrophilic surface properties with the water contact angle ≈0°. Such surfaces play an important role in providing uniform enhanced intensities over large areas (relative standard deviation ≈10%); moreover, these substrates are found to be highly sensitive (limit of detection ≈10-12 m for rhodamine 6G (R6G)). The results show that the hybrid SERS substrates can achieve the simultaneous detection of multicomponent mixtures of different target molecules, such as R6G, crystal violet, and methylene blue. Furthermore, the bending experiments show that about 70% of the SERS intensities are maintained after bending from ≈30° to 150°.

Polyimides (PIs) possess great mechanical properties, outstanding thermal stability, solvent inertness, and the ability to be converted into carbon by thermal carbonization. Although studies on carbon materials derived from PIs have been conducted, PI-derived one-dimensional (1D) carbon materials with high surface areas, especially carbon tubes or hollow carbon fibers, have been rarely investigated. In this work, we provide a simple and facile method to prepare hollow carbon fibers by carbonizing hollow PI fibers. Blend solutions of poly(amic acid) carboxylate salts (PAAS) and polystyrene (PS) are electrospun to form core-shell PS/PAAS fibers, in which the PS and PAAS domains are used as sacrificial and precursor materials, respectively. By imidizing the PAAS to PI and selectively removing PS, hollow PI fibers can be obtained. Finally, the hollow PI fibers are carbonized to form hollow carbon fibers. The fiber samples at different stages are examined by thermal gravimetric analysis (TGA), Raman spectrometry, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The infrared images show that the thermal energy transfer rates of the hollow carbon fibers are higher than those of the hollow PI and PS/PI core-shell fibers, which can be attributed to the better thermal conductivity of carbon resulting from the covalent sp2 bonding between carbon atoms and the high surface area of the hollow structure.

1D polymer nanomaterials have attracted significant interest in recent years because of their unique properties and promising applications in various fields. It is, however, still a challenge to fabricate polymer nanoarrays with desired sizes and controlled morphologies. Here, an unprecedented approach, the laser-assisted nanowetting (LAN) method, to selectively fabricate polymer nanoarrays is presented. Polystyrene (PS) is blended with gold nanorods (AuNRs), which are used to absorb the energy from the laser. After the blend films are brought in contact with AAO templates, the AuNRs at regions shone by the laser beams absorb the energy and heat the surrounding polymer chains, resulting in the formation of PS/AuNRs arrays in selected areas. This work paves a new research direction for developing template-based polymer nanomaterials.