Grafting maleic anhydride onto EVA and effect on the physical and rheological properties of PETG/EVA-g-MAH blends

Maleic anhydride (MAH) was grafted onto ethylene vinyl acetate copolymer (EVA) in the internal mixer in the presence of dicumyl peroxide (DCP), and a prepared reactive compatibilizer, MAH-g-EVA, was blended with Poly (ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETG). The gel content determination and element analysis (EA) was performed to confirm the grafting reaction. It was found that grafting reaction of MAH on to EVA could compete with crosslinking reaction of DCP during the modification process. In addition, the introduction of small amount of MAH showed a great effect on reducing gel content by decreasing crosslink reaction. As MAH content increased, grafted MAH concentration increased, whereas the grafting yield decreased. It was also confirmed that MAH-g-EVA acted as a reactive compatibilizer in the blend with PETG, and enhanced compatibility by reacting with the hydroxyl end groups, OH, of PETG. Addition of EVA in the blend leads a plastic deformation of PETG, and MAH had a great effect on enhancing interfacial adhesion resulting in significant increasing of % strain; however, improved compatibility could not be changed much in low strain tensile strength and Young's modulus. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Mechanical property enhancement of non‐bonding electrospun mats via adhesive

In the present study, the effect of adhesive on the morphology of different electrospun polymeric mats was investigated. The modification of two polymers, poly(methyl methacrylate) and poly(vinyl chloride), was carried out by blending the polymers with different amounts of poly(butyl acrylate) (PBA) adhesive to investigate the effect of different amounts of adhesive with heat hardener in hybrid mats. The introduction of various concentrations of PBA into different polymer solutions led to the formation of point‐bonded electrospun fibrous mats. Scanning electron microscopy images indicated that point‐bonded polymer/adhesive fibers were uniformly distributed throughout the mats. Fourier transform infrared spectrometry, contact angle measurements and thermogravimetric analysis were used to study the different properties of the hybrid mats. The tensile strength of the blended fibrous electrospun mats was increased effectively. This enhancement of the mechanical properties of the mats due to the presence of adhesive increases the number of potential applications of the electrospun mats, especially for mechanically weak polymers. Copyright © 2012 Society of Chemical Industry     

Direct stamping of silver nanoparticles toward residue-free thick electrode

Direct stamping of functional materials has been developed for cost-effective and process-effective manufacturing of nano/micro patterns. However, there remain several challenging issues like the perfect removal of the residual layer and realization of high aspect ratio. We have demonstrated facile fabrication of flexible strain sensors that have microscale thick interdigitated capacitors with no residual layer by a simple direct stamping with silver nanoparticles (AgNPs). Polyurethane (PU) prepolymer was utilized as an adhesive layer to transfer AgNPs more efficiently during the separation step of the flexible stamp from directly stamped AgNPs. Scanning electron microscopy images and energy dispersive x-ray spectroscopy analysis revealed residue-free transfer of microscale thick interdigitated electrodes onto two different flexible substrates (elastomeric and brittle) for the application to highly sensitive strain sensors.     

Erratum to: Nanocomposite quasi-solid-state electrolyte for highsafety lithium batteries

Nano Research - The third affiliation of the authors in the original version of this article was unfortunately wrongly written on page 3092 and the first page of the ESM. Instead of 3School of...     

A service composition oriented framework for configuring SMeet multiparty collaboration environments

To enable remote collaboration among knowledge workers, there has been extensive research about prototyping network-based multiparty collaboration environments. Particularly, it is necessary to solve the configuration difficulties that arise from different settings of various tools in traditional room-based collaboration systems. To ease these difficulties, in this paper, we design a service composition oriented framework for the SMeet (Smart Meeting Space) multiparty collaboration environments by following the SOA (service oriented architecture) design principles. The proposed framework aims to facilitate the flexible configuration of diverse networked devices and associated application tools for successful multiparty collaboration. According to a pre-defined template, it helps the operators and users to compose services that are dispersed across remote sites. By leveraging open-source agent middleware, we also develop a SMeet toolkit with GUIs (graphical user interfaces) to assist the easily-configurable realization of SMeet multiparty collaboration environments. The developed SMeet toolkit is utilized to realize a remote collaboration scenario between two SMeet prototype sites, by enabling the network-based interactive sharing of HD-quality media on networked tiled displays (NeTDs).     

Significant Enhancement of the Dielectric Constant through the Doping of CeO2 into HfO2 by Atomic Layer Deposition

Films of CeO₂ were deposited by atomic layer deposition (ALD) using a Ce(mmp)₄ [mmp = 1‐methoxy‐2‐methyl‐2‐propanolate] precursor and H₂O reactant. The growth characteristics and film properties of ALD CeO₂ were investigated. The ALD CeO₂ process produced highly pure, stoichiometric films with polycrystalline cubic phases. Using the ALD CeO₂ process, the effects of Ce doping into an HfO₂ gate dielectric were systematically investigated. Regardless of Ce/(Ce + Hf) composition, all ALD Ce_xHf_1?xO₂ films exhibited constant growth rates of approximately 1.3 Å/cycle, which is essentially identical to the ALD HfO₂ growth rates. After high‐temperature vacuum annealing at 900°C, it was verified, based on X‐ray diffraction and high‐resolution cross‐sectional transmission electron microscopy results, that all samples with various Ce/(Ce + Hf) compositions were transformed from nanocrystalline to stabilized cubic or tetragonal HfO₂ phases. In addition, the dielectric constant of the Ce_xHf_1?xO₂ films significantly increased, depending on the Ce doping content. The maximum dielectric constant value was found to be nearly 39 for the Ce/(Ce + Hf) concentration of ~11%.     

CO<Subscript>2</Subscript> decomposition using metal ferrites prepared by co-precipitation method

To catalytically decompose the greenhouse gas, CO₂, spinel structure M-ferrites (M=Co, Ni, Cu, Zn) were synthesized by chemical co-precipitation using metal salts and sodium hydroxide as starting materials. The crystallite size of the newly-prepared M-ferrites increased and the BET surface area decreased with increasing calcination temperature. A thermal analysis of the reduction and reoxidation of M-ferrites indicated that substitution of divalent transition metals (i.e., Cu, Ni and Co) into Fe₃O₄ improved the reduction kinetics in the order of Cu>Ni>Co. ZnFe₂O₄ was the most difficult compound to completely reduce due to its stable structure. Commercial samples of the reduced Fe₃O₄, CoFe₂O₄ and ZnFe₂O₄ showed an increase in mass through the reoxidation process, but it was much more difficult for oxygen atoms to enter the structure of the reduced samples of NiFe₂O₄ and CuFe₂O₄. The M-ferrites in a batch type reactor showed better efficiency than the commercial Fe₃O₄. Also found was that CoFe₂O₄ showed a high regeneration potential, although it required a higher critical reaction temperature. NiFe₂O₄ and CuFe₂O₄ were excellent candidate materials for CO₂ decomposition at lower temperatures.