Search results for "Composite"
showing 10 items of 4584 documents
PHOTO-OXIDATION OF PA6/GRAPHENE OXIDE FILMS
2014
Graphene oxide (GrO) was synthesized with Marcano’s method [1] and added at 0.5 and 1 wt% loading content to a polyamide 6 (PA6). In particular, three different techniques have been used for the preparation of the nanocomposites: (i) melt blending in a batch mixer, (ii) solvent casting in formic acid, (iii) preparation of a masterbatch by solvent casting and further melt processing. The films (80 m) were photo-oxidized in a QU-V chamber up to about 100 hours. The effect of filler content and preparation technique on the photo-stability of the nanocomposites has been followed by monitoring the change of the mechanical and spectroscopic properties undergone upon artificial exposure to UV-B l…
Photo-oxidation of nano- and micro-filled polypropylene
2010
Photo-oxidation of polyolefin/clay nanocomposite films: role of organoclay and matrix type
2009
Biocomposite PBAT/lignin blown films with enhanced photo-stability.
2022
Lignin can be obtained as a byproduct during cellulose-rich pulp fibers production and it is habitually treated as waste or intended for low-value destinations. However, due to UV absorption and mechanical properties, lignin can contribute to the fabrication of biodegradable blown films with superior performances. In this study, it was established the suitability of lignin for manufacturing biocomposite PBAT blown films with higher stiffness and photo-oxidation resistance. The effect of the filler concentration on the melt rheological behavior in non-isothermal elongational flow was investigated. The results allowed us to choose the correct filler concentration for producing films through a…
In situ characterization of passive films on al-ti alloy by photocurrent and impedance spectroscopy
1998
Abstract The anodic behaviour of an Al-Ti alloy (Ti-48Al-1V, atomic %) was investigated in different aqueous electrolytes. In all cases the alloy was passive owing to the growth of a barrier-like oxide film according to the high field mechanism. The study of the growth curves suggests partial dissolution of the film during the formation process in acidic solution. The kinetic parameters for film formation have been estimated in neutral solutions and the dielectric constant of the passive layer was roughly estimated. The in-situ characterization of the passive film revealed a n-type behaviour only for very low thicknesses, whilst thicker films showed insulator-like characteristics. The analy…
Physicochemical Characterization of Passive Films and Corrosion Layers by Differential Admittance and Photocurrent Spectroscopy
2009
Two different electrochemical techniques, differential admittance and photocurrent spectroscopy, for the characterization of electronic and solid state properties of passive films and corrosion layers are described and critically evaluated. In order to get information on the electronic properties of passive film and corrosion layers as well as the necessary information to locate the characteristic energy levels of the passive film/electrolyte junction like: flat band potential (Ufb), conduction band edge (EC) or valence band edge (EV), a wide use of Mott-Schottky plots is usually reported in corrosion science and passivity studies. It has been shown, in several papers, that the use of simpl…
Comparison of the electrochemical properties of hematite thin films prepared by spray pyrolysis and electrodeposition
2015
Abstract This manuscript reports differences between the photoelectrochemical (PEC) activity of hematite (α-Fe 2 O 3 ) photoanodes produced by cathodic electrodeposition (ED) and spray pyrolysis (SP) methods. Both methods yield nanostructured polycrystalline α-Fe 2 O 3 thin films without additional impurity phases. However, α-Fe 2 O 3 produced by ED is characterised to have better crystallinity and higher porosity, which was confirmed by XRD and SEM analysis. Owing to this, α-Fe 2 O 3 obtained by ED generates a photocurrent that is 2.5 times higher than α-Fe 2 O 3 thin films prepared by SP. Furthermore, the influence of the thickness of the α-Fe 2 O 3 thin films on the flat-band potential p…
Predicting the photoageing and photostabilization of polymer nanocomposites
2010
RGB photoelasticity applied to the analysis of membrane residual stress in glass
2011
The measurement of residual stresses is of great relevance in the glass industry. The analysis of residual stress in glass is usually made by photoelastic methods because glass is a photoelastic material. This paper considers the determination of membrane residual stresses in glass plates by automatic digital photoelasticity in white light (RGB photoelasticity). The proposed method is applied to the analysis of membrane residual stresses in some tempered glass. The proposed method can effectively replace manual methods based on the use of white light, which are currently provided by some technical standards.
Pyrene-benzoylthiophene Bichromophores as Selective Triplet Photosensitizers.
2006
Combination of the pyrene and benzoylthiophene units constitutes an interesting approach to design bichromophoric photosensitizers with increased intersystem crossing quantum yield and enhanced selectivity. The potential of this strategy has been illustrated in the present work by using a model photoisomerization reaction.