Ni-Pd bimetallic nanoparticle stabilized polymer membrane as an efficient dip-catalyst for oxidative coupling of aromatic amines to access symmetrical and unsymmetrical azo compounds.

The azo linkage is an important chemical motif with wide applications in the pharmaceutical, agrochemical, textile, paint, and food industries. The development of effective dip-catalysts that would convert aromatic amines to symmetric or asymmetric azobenzenes in the presence of aerobic molecular oxygen under mild conditions is really challenging. Here, we have developed a dip-catalyst by immobilizing poly(vinylpyrrolidone)(PVP) stabilized Ni-Pd bimetallic nanoparticles on a nylon-6 membrane through UV-crosslinking for performing such reactions.

Engaging a highly fluorescent conjugated polymer network for probing endogenous hypochlorite in macrophage cells: improved sensitivity signal amplification.

We have employed a triazine-based conjugated polymer network (CPN) for the selective detection of hypochlorite in a semi-aqueous environment. CPNs have been widely employed in gas capture, separation, and adsorption, but the fluorescent properties of CPNs possessing extensive π-conjugated systems tend to be unexplored. Herein, we report the photophysical properties of the CPN and investigate its sensing capability towards hypochlorite.

Side-Chain Modification in Conjugated Polymer Frameworks for the Electrocatalytic Oxygen Evolution Reaction.

Conjugated polymer frameworks (CPFs) have recently sparked tremendous research interest due to their broad potentials in various frontline application areas such as photocatalysis, sensing, gas storage, energy storage, etc. These framework materials, without sidechains or functional groups on their backbone, are generally insoluble in common organic solvents and less solution processable for further device applications. There are few reports on metal-free electrocatalysis, especially oxygen evolution reaction (OER) using CPF.

Efficient Moisture-Induced Energy Harvesting from Water-Soluble Conjugated Block Copolymer-Functionalized Reduced Graphene Oxide.

This Research Article demonstrates a very simple approach of a moisture-induced power-generating phenomenon using water-soluble rod-coil conjugated block copolymer (poly(3-hexythiophene)--poly(4-styrenesulfonic acid) (P3HT--PSSA)-modified reduced graphene oxide. The block copolymer-modified reduced graphene oxide (BCP-RGO) was prepared by noncovalent surface functionalization cum in situ reduction of graphene oxide. A simple device made from BCP-RGO can generate voltage upon exposure to water vapor or under different humidity conditions.

Metal-Immobilized Micellar Aggregates of a Block Copolymer from a Mixed Solvent for a SERS-Active Sensing Substrate and Versatile Dip Catalysis.

Here, we have reported micellar aggregations of an amphiphilic block copolymer in mixed solvent and their subsequent use as a template for the fabrication of a very dense, tunable metal nanoparticle-decorated surface for SERS and flexible dip catalysis applications. A silver nanoparticle-immobilized layer on silicon substrates shows excellent SERS (surface-enhanced Raman scattering)-based sensing performance for model analyte rhodamine B up to 10 M concentration with a well-defined calibration curve. Furthermore, a facile approach to the preparation of metal NP-immobilized BCP membranes as efficient dip catalyst for two model reactions (the reduction of nitrophenol and the Suzuki-Miyaura reaction of iodobenzene or 2,7-diiodofluorene with phenyl boronic acid) is also demonstrated.

Electrochemical and Electronic Properties of Transparent Coating from Highly Solution Processable Graphene Using Block Copolymer Supramolecular Assembly: Application toward Metal Ion Sensing and Resistive Switching Memory.

Here, we have discussed the preparation of a highly solution processable graphene from a novel supramolecular assembly consisting of block copolymer polystyrene--poly(4-vinylpyridine) (PS--P4VP) and pyrenebutyric acid (PBA)-modified reduced graphene oxide (RGO). The PBA molecules anchored on the graphene surface form supramolecules with PS--P4VP through H-bonding between the carboxylic acid group of 1-pyrenebutyric acid and the pyridine ring of P4VP. The formation of a supramolecular assembly results in a highly stable solution of reduced graphene oxide in common organic solvents, such as 1,4-dioxane and chloroform.

Amphiphilic and Thermoresponsive Conjugated Block Copolymer with Its Solvent Dependent Optical and Photoluminescence Properties: Toward Sensing Applications.

Herein, we present a new class of amphiphilic, thermoresponsive rod-coil conjugated block copolymer having regioregular poly(3-hexyl thiophene) and poly(N-isopropylacrylamide). Optical and luminescence properties of theses polymers significantly depend on the self-assembled nanostructures formed in different solvent and are easily tailored by chnaging the solvent composition or external stimuli like heat. Unique optical and electronic properties of this block copolymer are believed to make it promising for applications like sensor, fluorescence thermometer, optoelectronic, and bioelectronics devices.

Multilayer polymer thin films for fabrication of ordered multifunctional polymer nanocomposites.

Here, we describe a novel and versatile approach for fabrication of multilayer polymeric thin films with a tunable, ordered periodic structure in each layer using self-assembly of block copolymers. Different functional nanomaterials are selectively introduced in different layers with controlled arrays and network formation resulting in ordered multifunctional nanocomposite thin films.

Transparent, versatile chemical vapor sensor using supramolecular assembly of block copolymer and carbon nanotubes.

Here, a simple and novel approach is reported for developing a new class of transparent chemical vapor sensors with a low power consumption, high sensitivity, good selectivity, and excellent environmental stability by depositing multiwalled carbon nanotubes on prepatterned polymer substrates using supramolecular assembly. The patterned polymer substrates were fabricated from block copolymers, whereas the supramolecular assembly between the carbon nanotubes and block copolymer is utilized for the selective localization of carbon nanotubes at the block copolymer-air interface. The thin film devices made from the block copolymer and carbon nanotubes are highly transparent (transmittance > 90%) and respond to a wide range of solvents of different polarity, both hydrophilic and hydrophobic, with good selectivity and fast response time.

Vertically oriented arrays of polyaniline nanorods and their super electrochemical properties.

Highly dense arrays of ordered and aligned nanorods of polyaniline with 10 nm diameter on transparent ITO substrate have been successfully fabricated using supramolecular assemblies of block copolymer as scaffold material; the ordered arrays of polyaniline nanorods so fabricated were found to exhibit excellent electrochemical properties with an electrochemical capacitance value of 3407 F g(-1).

Structural hierarchy in melt-processed poly(3-hexyl thiophene)-montmorillonite clay nanocomposites: novel physical, mechanical, optical, and conductivity properties.

Poly(3-hexyl thiophene) (P3HT) organically modified montmorillonite (om-MMT) polymer nanocomposites (PNCs) are prepared in the melt-cooled state. Hierarchical structures up to third order, namely, side chain mesomorph formation followed by the interchain lamellar structure of P3HT and finally its intercalation within the clay tactoids are observed. The structures are supported by transmission electron microscopy (TEM) and wide-angle X-ray scattering (WAXS) experiments.