Poly(methyl methacrylate) reinforced poly(vinylidene fluoride) composites electrospun nanofibrous polymer electrolytes as potential separator for lithium ion batteries

Fabrication of nanofibrous polymer electrolyte membranes of poly(vinylidene fluoride) (PVdF) and poly(methyl methacrylate) (PMMA) in different proportion (PVdF:PMMA = 100:0, 80:20 and 50:50) by electrospinning is reported to investigate the influence of PMMA on lithium ion battery performance of PVdF membrane as separator. As-fabricated polymer electrospun nanofibrous membranes were characterized by SEM, FTIR, XRD, TGA and DSC for morphology, structure, crystallinity and thermal stability. PVdF–PMMA (50:50) polymer electrolyte membrane showed ionic conductivity 0.15 S/cm and electrolyte uptake 290% at room temperature. After 50 cycles, the discharge capacity 140 mAh/g of Li/PE/LiFePO4 cells with PVdF–PMMA (50:50) as polymer electrolyte (PE) membrane was found to be retained around 93.3%. The electrolyte uptake, ionic conductivity, and discharge capacity retention were improved by optimizing the proportion of PMMA in PVdF. Nanofibrous PVdF–PMMA (50:50) polymer electrolyte membrane was found to be a potential separator for lithium ion batteries

On the selective deposition of tin and tin oxide on various glasses using a high power diode laser

The deposition of SnO2 using a 120 W high power diode laser (HPDL) on both fused silica and soda-lime-silica glass has been successfully demonstrated. Deposition on both glass substrates was carried out with laser power densities of 650-1600 W cm-2 and at rates of 420-1550 mm min-1. The thickness of the deposited layers was typically around 250 m. The maximum theoretical coverage rate that it may be possible to achieve using the HPDL was calculated as being 3.72 m2 h-1. Owing to the wettability characteristics of Sn, it proved impossible to deposit the metal on either glass substrate. Evidence of solidified microstructures was observed, with the microstructures differing considerably across the same deposited track. These differences were attributed to variations in the solidification rate, R, and the thermal gradient, G. Adhesion of the SnO2 with the soda-lime-silica glass was found to be due to mechanical bonding. The adhesion of the SnO2 with the fused silica was seen to the result of a chemical bond arising from an interface region between the SnO2 and the fused silica glass substrate. This interface region was found to be comprised of mainly Si and rich with Sn3O4

AFM study of morphology and mechanical properties of a chimeric 2 spider silk and bone sialoprotein protein for bone regeneration

Atomic force microscopy (AFM) was used to assess a new chimeric protein consisting of a fusion protein of the consensus repeat for Nephila clavipes spider dragline protein and bone sialoprotein (6merþBSP). The elastic modulus of this protein in film form was assessed through force curves, and film surface roughness was also determined. The results showed a significant difference among the elastic modulus of the chimeric silk protein, 6merþBSP, and control films consisting of only the silk component (6mer). The behavior of the 6merþBSP and 6mer proteins in aqueous solution in the presence of calcium (Ca) ions was also assessed to determine interactions between the inorganic and organic components related to bone interactions, anchoring, and biomaterial network formation. The results demonstrated the formation of protein networks in the presence of Ca2þ ions, characteristics that may be important in the context of controlling materials assembly and properties related to bone formation with this new chimeric silk-BSP protein.Silvia Games thanks the Foundation for Science and Technology (FCT) for supporting her Ph.D. grant, SFRH/BD/28603/2006. This work was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283), the Chimera project (PTDC/EBB-EBI/109093/2008) funded by the FCT agency, the NIH (P41 EB002520) Tissue Engineering Resource Center, and the NIH (EB003210 and DE017207)

Recent advances and perspectives on starch nanocomposites for packaging applications

Starch nanocomposites are popular and abundant materials in packaging sectors. The aim of this work is to review some of the most popular starch nanocomposite systems that have been used nowadays. Due to a wide range of applicable reinforcements, nanocomposite systems are investigated based on nanofiller type such as nanoclays, polysaccharides and carbonaceous nanofillers. Furthermore, the structures of starch and material preparation methods for their nanocomposites are also mentioned in this review. It is clearly presented that mechanical, thermal and barrier properties of plasticised starch can be improved with well-dispersed nanofillers in starch nanocomposites

Poly(methyl methacrylate) reinforced poly(vinylidene fluoride) composites electrospun nanofibrous polymer electrolytes as potential separator for lithium ion batteries

Abstract Fabrication of nanofibrous polymer electrolyte membranes of poly(vinylidene fluoride) (PVdF) and poly(methyl methacrylate) (PMMA) in different proportion (PVdF:PMMA = 100:0, 80:20 and 50:50) by electrospinning is reported to investigate the influence of PMMA on lithium ion battery performance of PVdF membrane as separator. As-fabricated polymer electrospun nanofibrous membranes were characterized by SEM, FTIR, XRD, TGA and DSC for morphology, structure, crystallinity and thermal stability. PVdF–PMMA (50:50) polymer electrolyte membrane showed ionic conductivity 0.15 S/cm and electrolyte uptake 290% at room temperature. After 50 cycles, the discharge capacity 140 mAh/g of Li/PE/LiFePO4 cells with PVdF–PMMA (50:50) as polymer electrolyte (PE) membrane was found to be retained around 93.3%. The electrolyte uptake, ionic conductivity, and discharge capacity retention were improved by optimizing the proportion of PMMA in PVdF. Nanofibrous PVdF–PMMA (50:50) polymer electrolyte membrane was found to be a potential separator for lithium ion batteries

Ordering of fullerene and carbon nanotube thin films under energetic ion impact

We report the ordering of carbon nanostructures under energetic ion irradiation at low fluence (<5 x 10(11) ions/cm(2)). Fullerene thin films and multiwalled carbon nanotube (MWCNT) films were irradiated with 200 MeV Au and 60 MeV Ni ions at different ion fluences, respectively. The changes in the irradiated films have been investigated by means of Fourier transform infrared (FTIR) spectroscopy, x-ray diffraction, and Raman spectroscopy. FTIR and Raman spectroscopy show the improvement of vibration strength in low fluence irradiated fullerene and MWCNT films. X-ray diffraction analysis on low fluence irradiated fullerene films revealed the structural order along the (220) atomic planes. (C) 2008 American Institute of Physics

A novel in situ method for simultaneous growth of smart material single crystals and thin films

Development of a novel in situ method for simultaneous growth of single crystals and thin films of a smart material spinel is achieved. Material to be grown as metal-incorporated single crystal and thin film was taken as a precursor and put into a bath containing acid as a reaction speed-up reagent (catalyst) as well as a solvent with a metal foil as cation scavenger. By this novel method, zinc aluminate crystals having hexagonal facets and thin films having single crystalline orientation were prepared from a single optimized bath. Properties of both crystals and thin films were studied using an x-ray diffractometer and EDAX. $ZnAl_2O_4$ is a well-known wide bandgap compound semiconductor ($E_g$ = 3.8 eV), ceramic, opto-mechanical and anti-thermal coating in aerospace vehicles. Thus a space gmr technique was found to be a new low cost and advantageous method for in situ and simultaneous growth of single crystals and thin films of a smart material