We demonstrate the patterning of silica substrates with thymine (Thy-PS) and positively charged N-methylpyridinium (PVMP) polymers using photolithography and the subsequent orthogonal modification of these surfaces using diaminopyridine-functionalized polystyrene (DAP-PS) and carboxylate-derivatized CdSe/ZnS core-shell nanoparticles (COO-NP) through diamidopyridine-thymine three-point hydrogen bonding and pyridinium-carboxylate electrostatic interactions, respectively. This two-component orthogonal surface modification was accomplished in a self-sorting, single-step fashion, providing a versatile tool for the rapid and efficient creation of complex materials.

Utilization of ultrathin grafted nanoparticle (NP) [1][2][3][4] films to impart desired chemical/physical properties onto various solid substrates is a versatile and effective technique for preparing new composite and functional materials. [5][6][7][8] The fabrication of well-defined conductive metallic films is especially important owing to the increasing demand for high-speed and cost-effective electronic devices. [9] The conventional "topdown" lithographic methods, based on multistep resist patterning, etching, washing, and deposition continue to be the industrial fabrication standard; however, integrating these methods with recently developed "bottom-up" assembly strategies offers several preparative, geometric, and operational advantages. [8,[10][11][12][13][14] Metallic and semiconductor NPs are among the most versatile self-assembly building blocks due to their unique optical, magnetic, and electronic properties. [15,16] These properties can be readily manipulated upon assembly by tailoring the interfacial interactions. [17][18][19] The generation of multilayers or even monolayers of NP arrays on modified substrates provides an approach to transparent and/or flexible devices due to the mild fabrication conditions and its application to a variety of substrates. A planar monolayer array of NPs well packed but separated from each other (i.e., no agglomeration) is important for nanoelectronics, [20] as the electronic conduction in such structures varies from metallic to insulating owing to single-electron tunneling, [21][22][23] depending on the interparticle distance and the ligands present on the particles.[13]We recently reported specific and site-selective immobilization of monolayer-protected NPs on polymer-templated surfaces. [24,25] The use of a polymer interface to direct the deposition provides a versatile way to assemble ordered [26] and confined [25,27] 2D NP arrays through lithography and self-assembly. In addition, polymers can be coated on a wide range of substrates and with different topographies under mild conditions. Here, we report a versatile approach to the creation of very regular conductive NP films. In this method, positively charged polyvinyl N-methylpyridine (PVMP) was patterned via photochemical crosslinking, with the resultant cationic surface directing the adsorption of water-soluble citrate-protected Au NPs producing patterned nanostructured conductive films (Fig. 1). These surfaces could be further modified with thiol ligands allowing fine tuning of surface properties such as wettability and biocompatibility. Compared to most other fabrication methods, this photopattering and wet-deposition process is quite straightforward, and operates under ambient "wet" conditions. It also circumvents problems such as crack formation during heat annealing due to volume loss and weak substrate adhesion. Furthermore, this water/alcohol-based fabrication method is free of organic solvents and COMMUNICATION

Silkworm fibers have attracted widespread attention for their superb glossy texture and promising mechanical performance.

[reaction: see text] A model system has been developed to study the redox behaviors of flavin derivatives appended onto random polystyrene copolymers through "click" chemistry strategies. The results demonstrate that flavin units attached onto polymers exhibit site-isolated redox behaviors, yielding new materials with electrochemically tunable associations (K(a)(ox) = 450 M(-)(1), K(a)(red) = 18,200 M(-)(1)) to complementary diamidopyridine (DAP) functionality.

Specific three-point hydrogen bonding between diamidopyridine (DAP) and thymine (Thy) was employed to reversibly anchor "brush-like" Tri-DAP end-functionalized polystyrene onto Thy-modified silica surfaces.

No abstract

We demonstrate the use of molecular recognition to control the spatial distribution of guest molecules within block copolymer films. Block copolymers bearing recognition units were combined with complementary and noncomplementary molecules, and the extent of segregation of these molecules into the different domain types within microphase-separated thin films was quantitatively analyzed using dynamic secondary ion mass spectrometry (SIMS). Complementarity between the guest molecules and the polymer functionalities proved to be a key factor and an efficient tool for directing the segregation preference of the molecules to the different domain types. The effect of segregation preference on the glass transition temperature was studied using differential scanning calorimetry (DSC), and the results corroborate the SIMS findings. In a complementary study, guests with tunable sizes (via dendron substituents) were used to control block copolymer morphology. Morphological characterization using transmission electron microscopy (TEM) and X-ray diffraction reveal that selectivity differences can be directly translated into the ability to obtain different morphologies from recognition unit-functionalized block copolymer scaffolds.

Developments in self-assembly methods allow access to hierarchical materials featuring a wide range of functionality and applications. Polymer-based self-assembly of nanoparticles opens up new avenues for the fabrication of highly structured nanocomposites that can serve as bridges between 'bottom-up' and 'top-down' methods. Of various interactions leading to self-assembly of nanocomposites, hydrogen bonding and electrostatic interactions are commonly utilized. In this review, we illustrate the design and subsequent property tuning of various self-assembled nanocomposite materials that were developed based on these interactions.