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排序方式: 共有755条查询结果,搜索用时 15 毫秒
131.
Fernando A. Oliveira Neri Alves José A. Giacometti Carlos J. L. Constantino Luiz H. C. Mattoso Ana M. O. A. Balan Aldo E. Job 《应用聚合物科学杂志》2007,106(2):1001-1006
This work describes the preparation and characterization of composite materials obtained by the combination of natural rubber (NR) and carbon black (CB) in different percentages, aiming to improve their mechanical properties, processability, and electrical conductivity, aiming future applications as transducer in pressure sensors. The composites NR/CB were characterized through optical microscopy (OM), DC conductivity, thermal analysis using differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMA), thermogravimetry (TGA), and stress–strain test. The electrical conductivity varied between 10?9 and 10 S m?1, depending on the percentage of CB in the composite. Furthermore, a linear (and reversible) dependence of the conductivity on the applied pressure between 0 and 1.6 MPa was observed for the sample with containing 80 wt % of NR and 20% of CB. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
132.
Jeremy P. Wu Rees D. Rawlings Aldo R. Boccaccini Ivo Dlouhy Zdenek Chlup 《Journal of the American Ceramic Society》2006,89(8):2426-2433
A novel glass–ceramic material was developed from the melt of a TiO2 -containing iron-making slag with additional waste glass. The high percentage (∼20 wt% TiO2 ) of this network-modifying oxide has promoted a crystallization of the parent glass, resulting in a fine-grained, homogeneous polycrystalline material with high mechanical properties ( E =120 GPa, flexural strength=∼180 MPa, and Vickers hardness=7 GPa) after a heat treatment at 1100°C for 2 h. The room temperature and elevated temperature fracture toughness were also studied. The main crystalline phases of the glass–ceramic material were of the pyroxene series until heat-treatment temperature reached 1000°C, at which titanium-rich perovskite and armalcolite crystals became the dominant phases. The end material is high-strength, aesthetically acceptable (metallic gray or opaque brown colored), and suitable for structural and architectural applications. 相似文献
133.
Electrophoretic deposition of carbon nanotubes 总被引:1,自引:0,他引:1
Aldo R. Boccaccini Johann Cho Judith A. Roether Boris J.C. Thomas E. Jane Minay Milo S.P. Shaffer 《Carbon》2006,44(15):3149-3160
Electrophoretic deposition (EPD) has been gaining increasing interest as an economical and versatile processing technique for the production of novel coatings or films of carbon nanotubes (CNTs) on conductive substrates. The purpose of the paper is to present an up-to-date comprehensive overview of current research progress in the field of EPD of CNTs. The paper specifically reviews the preparation and characterisation of stable CNT suspensions, and the mechanism of the EPD process; it includes discussion of pure CNT coatings and CNT/nanoparticle composite films. A complete discussion of the EPD parameters is presented, including electrode materials, deposition time, electrode separation, deposition voltage and resultant electric field. The paper highlights potential applications of the resulting CNT and CNT/composite structures, in areas such as field emission devices, fuel cells, and supercapacitors. 相似文献
134.
Ezio Amerio Marco Sangermano Giulio Malucelli Aldo Priola Giancarlo Rizza 《大分子材料与工程》2006,291(10):1287-1292
Summary: Organic‐inorganic nanocomposite hybrid coatings were prepared through a dual‐cure process involving cationic photopolymerization of a hyperbranched epoxy functionalized resin and subsequent condensation of an alkoxysilane inorganic precursor. All the formulations investigated gave rise to photocured films characterized by high gel content values. An increase in glass transition temperature and an increase in storage modulus above Tg in the rubbery plateau is observed with increasing TEOS content in the photocurable formulation. The important role of GPTS on reducing the inorganic domain size and avoiding macroscopic phase separation was demonstrated by TEM analyses.
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138.
Pooja Basnett Jonathan C. Knowles Fatemah Pishbin Caroline Smith Tajalli Keshavarz Aldo R. Boccaccini Ipsita Roy 《Advanced Engineering Materials》2012,14(6):B330-B343
Novel poly(3‐hydroxyoctanoate), P(3HO), and bacterial cellulose composites have been developed. P(3HO) is hydrophobic in nature whereas bacterial cellulose is extremely hydrophilic in nature. Therefore, homogenized bacterial cellulose has been chemically modified in order to achieve compatibility with the P(3HO) matrix. Modified bacterial cellulose microcrystals and P(3HO) have been physically blended and solvent casted into two‐dimensional composite films. Mechanical characterization shows that the Young's modulus of the P(3HO)/bacterial cellulose composites is significantly higher in comparison to the neat P(3HO) film. The melting temperature (Tm) of the composites is lower while the glass transition temperature (Tg) is higher than the neat P(3HO) film. Also, the composite film has a rougher surface topography as compared to the neat P(3HO) film. A month's in vitro degradation study has been carried out in Dulbeccos modified eagle medium and in phosphate buffer saline. The incorporation of modified bacterial cellulose microcrystal in the P(3HO) film has increased the degradability of the composite film. Finally, in vitro biocompatibility studies using human microvascular endothelial cells established the biocompatibility of the P(3HO)/bacterial cellulose microcrystal films. The cell proliferation was 50–110% higher on the P(3HO)/bacterial cellulose composites as compared to the neat P(3HO) film. Hence, in this study, for the first time, P(3HO)/bacterial cellulose composites have been developed. The addition of bacterial cellulose has resulted in properties that are highly desirable for medical applications including the development of biodegradable stents. 相似文献
139.
Giovanetti LJ Ramallo-López JM Foxe M Jones LC Koebel MM Somorjai GA Craievich AF Salmeron MB Requejo FG 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(3):468-473
Polyvinylpyrollidone (PVP)-capped platinum nanoparticles (NPs) are found to change shape from spherical to flat when deposited on mesoporous silica substrates (SBA-15). Transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and extended X-ray absorption fine structure (EXAFS) analyses are used in these studies. The SAXS results indicate that, after deposition, the 2 nm NPs have an average gyration radius 22% larger than in solution, while the EXAFS measurements indicate a decrease in first neighbor co-ordination number from 9.3 to 7.4. The deformation of these small capped NPs is attributed to interactions with the surface of the SBA-15 support, as evidenced by X-ray absorption near-edge structure (XANES). 相似文献
140.
Toschi F Orlanducci S Tamburri E Guglielmotti V Terranova ML Di Carlo A Reale A Falessi C 《Journal of nanoscience and nanotechnology》2010,10(12):8336-8340
The thermal performances of nanocomposite layers formed by Single-walled Carbon Nanotubes (SWCNT) dispersed in 2 different kind of polydimethyl-siloxane (PDMSO) matrices has been investigated by measuring the thermal resistance under conditions similar to the ones used for thermal management in microelectronics. A series of nanocomposite samples with thickness in the range 25 microm(-1) cm have been tested. The nanocomposites were prepared varying the amounts of nanotubes embedded in the matrix (from 0.1 to 5%w). In some cases also microsized graphites were mixed to the nanotube's fillers. For 25 micron thick layers, the thermal resistance of the neat silicone specimen can be reduced of 54% with the addition of 2%w carbon nanotubes. The variation of thermal conductivity as a function of the SWCNT's loading is reported and discussed. Furthermore the dispersion's effects of the nanotubes in the layers and the effects on the realization of a net-like system have been investigated. 相似文献