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Atomic force microscopy (AFM), in particular force spectroscopy, is a powerful tool for understanding the supramolecular structures associated with polymers grafted to surfaces, especially in regimes of low polymer density where different morphological structures are expected. In this study, we utilize force volume mapping to characterize the nanoscale surfaces of Ag nanocubes (AgNCs) grafted with a monolayer of polyethylene glycol (PEG) chains. Spatially resolved force−distance curves taken for a single AgNC were used to map surface properties, such as adhesion energy and deformation. We confirm the presence of surface octopus micelles that are localized on the corners of the AgNC, using force curves to resolve structural differences between the micelle “bodies” and “legs”. Furthermore, we observe unique features of this system including a polymer corona stemming from AgNC−substrate interactions and polymer bridging stemming from particle−particle interactions. 

Abstract Checkerboard lattices—where the resulting structure is open, porous, and highly symmetric—are difficult to create by self-assembly. Synthetic systems that adopt such structures typically rely on shape complementarity and site-specific chemical interactions that are only available to biomolecular systems (e.g., protein, DNA). Here we show the assembly of checkerboard lattices from colloidal nanocrystals that harness the effects of multiple, coupled physical forces at disparate length scales (interfacial, interparticle, and intermolecular) and that do not rely on chemical binding. Colloidal Ag nanocubes were bi-functionalized with mixtures of hydrophilic and hydrophobic surface ligands and subsequently assembled at an air–water interface. Using feedback between molecular dynamics simulations and interfacial assembly experiments, we achieve a periodic checkerboard mesostructure that represents a tiny fraction of the phase space associated with the polymer-grafted nanocrystals used in these experiments. In a broader context, this work expands our knowledge of non-specific nanocrystal interactions and presents a computation-guided strategy for designing self-assembling materials. 

Abstract Durable and conductive interfaces that enable chronic and high‐resolution recording of neural activity are essential for understanding and treating neurodegenerative disorders. These chronic implants require long‐term stability and small contact areas. Consequently, they are often coated with a blend of conductive polymers and are crosslinked to enhance durability despite the potentially deleterious effect of crosslinking on the mechanical and electrical properties. Here the grafting of the poly(3,4 ethylenedioxythiophene) scaffold, poly(styrenesulfonate)‐b‐poly(poly(ethylene glycol) methyl ether methacrylate block copolymer brush to gold, in a controlled and tunable manner, by surface‐initiated atom‐transfer radical polymerization (SI‐ATRP) is described. This “block‐brush” provides high volumetric capacitance (120 F cm^─3), strong adhesion to the metal (4 h ultrasonication), improved surface hydrophilicity, and stability against 10 000 charge–discharge voltage sweeps on a multiarray neural electrode. In addition, the block‐brush film showed 33% improved stability against current pulsing. This approach can open numerous avenues for exploring specialized polymer brushes for bioelectronics research and application.