Multimodal nano-imaging in electrochemical environments is important across many areas of science and technology. Here, scanning electrochemical microscopy (SECM) using an atomic force microscope (AFM) platform with a nanoelectrode probe is reported. In combination with PeakForce tapping AFM mode, the simultaneous characterization of surface topography, quantitative nanomechanics, nanoelectronic properties, and electrochemical activity is demonstrated. The nanoelectrode probe is coated with dielectric materials and has an exposed conical Pt tip apex of ∼200 nm in height and of ∼25 nm in end-tip radius. These characteristic dimensions permit sub-100 nm spatial resolution for electrochemical imaging. With this nanoelectrode probe we have extended AFM-based nanoelectrical measurements to liquid environments. Experimental data and numerical simulations are used to understand the response of the nanoelectrode probe. With PeakForce SECM, we successfully characterized a surface defect on a highly-oriented pyrolytic graphite electrode showing correlated topographical, electrochemical and nanomechanical information at the highest AFM-SECM resolution. The SECM nanoelectrode also enabled the measurement of heterogeneous electrical conductivity of electrode surfaces in liquid. These studies extend the basic understanding of heterogeneity on graphite/graphene surfaces for electrochemical applications.

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A series of poly(3-hexylthiophene)-block-poly-(ethylene glycol) (P3HT-b-PEG) with constant P3HT block length block and variable PEG block lengths are presented. Alkyne-functionalized P3HT with high absolute molecular weight of 11.4 kg/mol is combined with azide-functionalized PEGs via copper-catalyzed alkyne−azide cycloaddition (CuAAC). The resulting P3HT-b-PEG block copolymers have PEG weight fractions between 15 and 64 wt %. In bulk materials the crystallinity in the conjugated block is similar to pure P3HT, while the crystallinity of PEG is influenced with decreasing PEG block length. On addition of MeOH as a nonsolvent for the P3HT block, these block copolymers are able to form stable micellar aggregates if the PEG fraction is >31 wt %. In AFM, DLS, and cryo-TEM, P3HT-b-PEG micelles are found to have a spherical or cylindrical shape with diameters of around 25 nm and lengths between 40 nm and some hundred nanometers. It is found that short PEG blocks lead to bigger block copolymer micelles. Thus, a correlation of composition on solution structure and its consequences on the crystallization of both blocks is given.