The nanometer-scale architectures in thin films of self-assembling block copolymers have inspired a variety of new applications. For example, the uniformly sized and shaped nanodomains formed in the films have been used for nanolithography, nanoparticle synthesis, and high-density information storage media. Imperative to all of these applications, however, is a high degree of control over orientation of the nanodomains relative to the surface of the film as well as control over order in the plane of the film. Induced fields including electric, shear, and surface fields have been demonstrated to influence orientation. Both heteroepitaxy and graphoepitaxy can induce positional order on the nanodomains in the plane of the film. This article will briefly review a variety of mechanisms for gaining control over block copolymer order as well as many of the applications of these materials. Particular attention is paid to the potential of perfecting long-range two-dimensional order over a broader range of length scales and the extension of these concepts to functional materials and more complex architectures.

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Patterning with block copolymer thin films

Control of protein immobilization: coupling immobilization and site-directed mutagenesis to improve biocatalyst or biosensor performance.

https://rua.ua.es/dspace/bitstream/10045/57890/5/2015_Barbosa_etal_BiotechAdv_preprint.pdf

Strategies for the one-step immobilization–purification of enzymes as industrial biocatalysts

Polymer nanocomposites have been investigated for about three decades. To get deep insights into the modifying effects of various nanofillers on mechanical and physical properties of polymer nanocomposites, the three basic aspects of processing, characterization and properties are critically reviewed in this paper. Nanofillers can be classified into three major types of two-dimensional (2D) layered, one-dimensional (1D) fibrous and zero-dimensional (0D) spherical ones and this review thus discusses in detail the processing, characterization and properties of the three types of polymer nanocomposites. It starts with an introduction of various nanoscale fillers such as two-dimensional (2D) nano-clay, graphene and MXene, one dimensional (1D) carbon nanofibers and nanotubes, zero dimensional (0D) silica nanoparticles and ZnO quantum dots as well as nanofiller-polymer interfaces. The processing of these polymer nanocomposites using different methods and the characterization of nanofillers and polymer nanocomposites using various techniques are described. Finally, the mechanical and physical properties of these polymer nanocomposites are discussed by considering the effects of nanofiller type, dispersion and contents; also, interface properties show significant effects on the mechanical properties of polymer nanocomposites and are discussed in some details.

Some basic aspects of polymer nanocomposites: A critical review

Magnetic nanoparticles of cobalt ferrite (CoFe2O4) have been synthesized in a homogeneous aqueous solution without any template and subsequent heat treatment. The average particle size could be varied in the range of 2–14 nm by controlling coprecipitation temperature of Co2+ and Fe3+ ions in alkaline solution although the size distribution is pretty wide. As the precipitation temperature increased in the range of 20–80°C, the average particle size also increased. However, there is a considerable change in XRD crystallinity and the average size of the nanoparticles at the precipitation temperature between 40°C and 60°C. While the nanoparticles prepared at the temperature below 40°C show superparamagnetic relaxation at room temperature with blocking temperatures between 75 and 200 K, the samples prepared at the temperature higher than 60°C consist of both superparamagnetic and ferrimagnetic nanoparticles that result in magnetic coercivity at room temperature. Mossbauer spectra of the samples also confirmed their magnetic properties and wide size distribution in each sample. The analysis of the spectra gave a rough estimation of the ratio of superparamagnetic and ferromagnetic nanoparticles in each sample at various temperatures.

/pdf/synthesis-and-characterization-of-cofe2o4-magnetic-40ps8uiegb.pdf

Synthesis and characterization of CoFe2O4 magnetic nanoparticles prepared by temperature-controlled coprecipitation method

The development of self-assembled magnetic CoFe2O4 nanoparticles within polymer matrices at room temperature is reported. Diblock copolymers consisting of poly (norbornene) and poly (norbornene-dicarboxcylic acid) (NOR/NORCOOH) were synthesized. The self-assembly of the mixed metal oxide within the NORCOOH block was achieved at room temperature by processing the copolymer nanocomposite using wet chemical methods. Morphology and magnetic properties were determined by superconducting quantum interference device magnetometry, transmission electron microscopy, wide angle x-ray diffraction, and 57Fe Mossbauer spectroscopy. The CoFe2O4 nanoparticles are uniformly dispersed within the polymer matrix, and have an average radius of 4.8±1.4 nm. The nanocomposite films are superparamagnetic at room temperature and ferrimagnetic at 5 K.

Magnetic properties of CoFe2O4 nanoparticles synthesized through a block copolymer nanoreactor route

Magnetic properties and morphology of block copolymer-cobalt oxide nanocomposites

Specific capture of target proteins by oriented antibodies bound to tyrosinase-immobilized Protein A on a polyallylamine affinity membrane surface

Polydispersity control in ring opening metathesis polymerization of amphiphilic norbornene diblock copolymers

Compositions and methods are taught for directing the orientation of an immobilized capture biomolecule on a hydrophobic membrane. The method comprises layering at least one tie layer on a hydrophobic membrane, adding an amine functional layer on top of at least one tie layer; and attaching an alignment biomolecule to the amine functional layer. The alignment biomolecule has the ability to either capture a target biomolecule itself and thus be considered a capture biomolecule, or bind and orient the immobilized capture biomolecule so as to maximize the binding activity of the immobilized capture biomolecule. In one embodiment, a nickel-coordinated amine functional layer binds with a histidine-tagged alignment biomolecule. In another embodiment, an amine functional layer reacts, via tyrosinase catalysis, with a tyrosine residue in an alignment biomolecule.

Sufi R. Ahmed

Papers

Magnetic properties of CoFe2O4 nanoparticles synthesized through a block copolymer nanoreactor route

Magnetic properties and morphology of block copolymer-cobalt oxide nanocomposites

Specific capture of target proteins by oriented antibodies bound to tyrosinase-immobilized Protein A on a polyallylamine affinity membrane surface

Polydispersity control in ring opening metathesis polymerization of amphiphilic norbornene diblock copolymers

Affinity membrane for capture of a target biomolecule and formation thereof by site-directed immobilization of a capture biomolecule