Organometallic Block Copolymers Research Articles

Enhanced Charge Transport in Enzyme-Wired Organometallic Block Copolymers for Bioenergy and Biosensors

Wiring of glucose oxidase (GOx) onto electrode surface was successfully achieved by cross-linked networks of organometallic block copolymers comprising electroactive ferrocene moieties and chemically cross-linkable diene groups, poly(ferrocenyldimethylsilane-b-isoprene)s (PFS–PIs). Different nanoscale morphologies of PFS–PIs, i.e., bicontinuous structure, nanowires, and nanoparticles, have been derived by varying molecular weights and casting solvents. Upon examining catalytic current responses of the GOx integrated PFS–PI systems, notably, the morphology of PFS–PI is found out to be a crucial parameter in determining the efficiency of electron transfer. For example, the use of bicontinuous PFS–PI confirms 2–50 times improved catalytic current densities, compared with the values of other morphologies; the maximum catalytic current of glucose oxidation was 0.7 mA/cm2 at 70 mM glucose concentration. The biosensing ability of the fabricated electrode with structural optimization was also exploited, and good ...

Metal‐Containing Polymers: Building Blocks for Functional (Nano)Materials

The incorporation of metallic units into polymer chains has emerged as a promising route towards functional metal-containing (nano)materials. The resulting polymers possess rich functions derived from their metallic elements, such as redox, optical, catalytic and magnetic properties. In addition, the directional and dynamic nature of metal coordination interactions provides further variables for the exploration of novel materials with designed nanostructures. These types of polymers can be synthesized through direct metal-ligand coordination or chain polymerization of metal containing monomers. Depending on the polymerization techniques and starting components, the resulting polymers, akin to their organic counterparts, can be produced in the form of insoluble networks, processible chain structures, gels or colloids. Research into this rising multidisciplinary subject has benefited from recent progress in several related areas such as supramolecular chemistry, colloidal chemistry etc., with the combination of the relative merits of each ensuring further developments in each individual discipline. For example, as a result of studies into organometallic block copolymers self-assembly behavior, living supramolecular polymerization has been unprecedentedly realized for the architectural design of micelles (see image on the right). Nevertheless, the field is still in a developmental stage and offers ample opportunities for fundamental research, as well as material exploration. In this Feature Article, we intend to overview the field with a brief survey of recent literature.

Organoboronium amphiphilic block copolymers

AbstractA new class of amphiphilic organometallic block copolymers with cationic organoboron pendant groups was developed. Selective replacement of one of the bromine substitutents on each boryl group of the block copolymer PSBBr2‐b‐PS with an organometallic reagent ArM (ArM = 2,4,6‐trimethylphenyl copper, 4‐t‐butylphenyltrimethyl tin) followed by treatment with 2,2′‐bipyridine gave the novel block copolymers [3Ar](Br)n as light yellow solid materials that show good stability in air and moisture and high solubility in most organic solvents. Their structure and composition were confirmed by multinuclear NMR, GPC, and elemental analysis. Highly regular micellar aggregates form in block‐selective solvents (e.g., MeOH, toluene) as demonstrated by 1H NMR, dynamic light scattering, and transmission electron microscopy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6612–6618, 2009

Redox-controlled micellization of organometallic block copolymers

Polystyrene-block-polyferrocenylsilane (PS-b-PFS) diblock copolymers were stoichiometrically oxidized in solution using salts of the one-electron oxidant tris(4-bromophenyl)ammoniumyl. Due to a redox-induced polarity change for the PFS block, self-assembly into well-defined spherical micelles occurs. The micelles are composed of a core of partially oxidized PFS segments and a corona of PS. When the micellar solutions were treated with the reducing agent decamethylcobaltocene, the spherical micelles disassemble and regenerate unassociated and pristine PS-b-PFS free chains.

Catalysts from Self‐Assembled Organometallic Block Copolymers

Catalysts from Self‐Assembled Organometallic Block Copolymers

Organometallic Block Copolymers as Catalyst Precursors for Templated Carbon Nanotube Growth

The use of organic–organometallic block copolymers as catalyst precursors for templated carbon nanotube (CNT) growth (see Figure) is demonstrated for the first time. A thin film of block copolymer was treated with O2 plasma to produce ordered iron‐containing catalyst nanoparticle arrays, which are efficient catalysts for CNT growth. This approach allows control of catalyst domain size and spacing by tailoring block copolymer composition.

Effect of chemical oxidation on the self-assembly of organometallic block copolymers.

The thermodynamic interactions in poly(styrene-block-ferrocenyldimethylsilane) and poly(isoprene-block-ferrocenyldimethylsilane) copolymers were systematically tuned by oxidation of the ferrocene moieties with silver nitrate. Small-angle X-ray scattering experiments show that oxidizing 8% of the ferrocene moieties lowers the order-disorder transition temperature of the copolymers by as much as 40 degrees C.

Nanostructured Thin Films of Organic–Organometallic Block Copolymers: One-Step Lithography with Poly(ferrocenylsilanes) by Reactive Ion Etching

The deposition of thin films of inorganic nanoclusters as a route to one-step lithography has been achieved using block copolymers with inherent inorganic (Fe and Si) components. Nanodomains of the organometallic part are resistant to removal during the subsequent O2 etch, which results in well-ordered and separate domains of iron and silicon oxides, as can be seen in the Figure.

Living Anionic Ring-Opening Polymerization of Unsymmetrically Substituted Silicon-Bridged [1]Ferrocenophanes; A Route to Organometallic Block Copolymers with Amorphous Poly(ferrocenylsilane) Blocks

Living anionic ring-opening polymerization methodology for silicon-bridged [1]ferrocenophanes has been extended to unsymmetrically substituted monomers. This permits access to well-defined amorphous poly(ferrocene) homopolymers and organometallic block copolymers, such as polystyrene-b-poly(ferrocenylmethylphenylsilane), with an amorphous poly(ferrocenylsilane) block. This allows phase separation to occur at lower temperatures, which should facilitate applications in which organometallic nanodomains are desirable.

Synthesis of zinc sulfide clusters and zinc particles within microphase-separated domains of organometallic block copolymers

Synthesis of zinc sulfide clusters and zinc particles within microphase-separated domains of organometallic block copolymers