Search results for "DIFFERENTIAL SCANNING CALORIMETRY"
showing 10 items of 285 documents
Insights into the effect of the spacer on the properties of imidazolium based AIE luminogens
2021
Abstract With the aim to obtain organic salts with potential applications in high performance molecular electronics, we combined properties of π-conjugated spacers, like 1,4-diethynylbenzene and 1,6-diethynylpyrene, with the ones of both imidazole and imidazolium units. Physico-chemical properties of obtained fluorescent organic salts were investigated performing thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC) and cyclic voltammetry measurements (CV). Photophysical behavior of the salts was analyzed in conventional solvents and ionic liquids, by UV–vis and fluorescence investigation. Solution phase aggregation study revealed that these salts self-assemble in conve…
Proton Transport in Membranes Prepared from Sulfonated Polystyrene-Poly(vinylidene fluoride) Blends
2001
The preparation of new cation-exchange membranes from polymer composites based on poly(vinylidene fluoride), sulfonated polystyrene-co-divinylbenzene, and antimonic acid is reported. The thermal properties of the composites have been characterized by differential scanning calorimetry. Values of the transport number of protons in the membranes were obtained from the observable electric potential. It is defined from the potential difference measured between the electrodes reversible to one of the constituent ions in equilibrium with the system. When compared with Nafion cation-exchange membranes, the membranes described in this work exhibit interesting proton transport properties that could m…
Aging resistance of bio-epoxy jute-basalt hybrid composites as novel multilayer structures for cladding
2017
Abstract Aging resistance of jute reinforced laminates is compared with two jute/basalt hybrid laminates prepared with different stacking sequences (i.e., sandwich and intercalated configuration). To this aim, composites are exposed to cyclic conditions comprising hygrothermal stress and UV radiation to promote an accelerated aging, for a period of 84 days. Specimens of each laminate are tested after 14, 28, 56 and 84 days, respectively. Quasi-static flexural tests, Charpy impact tests and dynamic mechanical tests are performed according to international ASTM and ISO standards. Furthermore, scanning electron microscopy and differential scanning calorimetry are used to evaluate the morpholog…
Reversible stress softening of collagen based networks from the jumbo squid mantle (Dosidicus gigas).
2014
Dosidicus gigas is the largest and one of the most abundant jumbo squids in the eastern Pacific Ocean. In this paper we have studied the muscle of the mantle of D. gigas (DGM). Morphological, thermal and rheological properties were assessed by means of atomic force microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, thermogravimetry and oscillatory rheometry. This study allowed us to assess the morphological and rheological properties of a collagen based network occurring in nature. The results showed that the DGM network displays a nonlinear effect called reversible stress softening (RSS) that has been previously described for …
Thermosetting composites based on bronze particles for archaeological and artistic metal heritage cloning
2018
peer-reviewed Artificial Metals are polymeric semi-metallic composites obtained by combining thermosetting resins with atomized metal powders in order to achieve composite materials capable of reproducing metals, even in a rusty or corroded condition. These composites provide a solution for the reproduction of archaeological artefacts, sculptures, and ornaments for the purpose of conservation. This work explores mechanical properties of three different resins bronze composites loaded with two different proportions of metal filler. The degree of conversion of the samples was measured by differential scanning calorimetry (DSC) and flexural tests were carried out to determine their mechanical …
Synthesis and thermoelectric characterisation of bismuth nanoparticles
2009
An effective method of preparation of bismuth nanopowders by thermal decomposition of bismuth dodecyl-mercaptide Bi(SC12H25)3 and preliminary results on their thermoelectric properties are reported. The thermolysis process leads to Bi nanoparticles due to the efficient capping agent effect of the dodecyl-disulfide by-product, which strongly bonds the surface of the Bi clusters, preventing their aggregation and significantly reducing their growth rate. The structure and morphology of the thermolysis products were investigated by differential scanning calorimetry, thermogravimetry, X-ray diffractometry, 1H nuclear magnetic resonance spectroscopy, scanning electron microscopy, and energy dispe…
Glassy PEEK‐WC vs Rubbery Pebax®1657 Polymers: Effect on the Gas Transport in CuNi‐MOF Based Mixed Matrix Membranes
2020
Mixed matrix membranes (MMMs) are seen as promising candidates to overcome the fundamental limit of polymeric membranes, known as the so-called Robeson upper bound, which defines the best compromise between permeability and selectivity of neat polymeric membranes. To overcome this limit, the permeability of the filler particles in the MMM must be carefully matched with that of the polymer matrix. The present work shows that it is not sufficient to match only the permeability of the polymer and the dispersed phase, but that one should consider also the individual contributions of the diffusivity and the solubility of the gas in both components. Here we compare the gas transport performance o…
Relevant factors for the eco-design of polylactide/sisal biocomposites to control biodegradation in soil in an end-of-life scenario
2017
[EN] The eco-design considers the factors to prepare biocomposites under an end-of-life scenario. PLA/sisal biocomposites were obtained from amorphous polylactide and sisal loadings of 10, 20 and 30 wt% with and without coupling agent, and subjected to biodegradation in soil according to standard IS0846. Mass loss, differential scanning calorimetry and size-exclusion chromatography were used for monitoring biodegradation. A statistical factorial analysis based on the molar mass M-n, and crystallinity degree X-c pointed out the relevance and interaction of amount of fibre and use of coupling agent with the time of burial in soil., During the preparation of biocomposites, chain scission provo…
Quantification of low levels of amorphous content in maltitol
2004
A method for the quantification of low levels of amorphous content of maltitol with hyper-DSC (high speed DSC) was developed. The method is based on the fact that the change of specific heat ( � Cp) at the glass transition is linearly proportional to the amorphous content. Twelve synthetic mixtures with various degrees of crystalline and amorphous maltitol were prepared. � Cp was determined at both fictive and
Design of Bistable Gold@Spin‐Crossover Core–Shell Nanoparticles Showing Large Electrical Responses for the Spin Switching
2019
<p>A simple protocol to prepare core-shell gold@spin-crossover (Au@SCO) nanoparticles (NPs) based on the 1D spin-crossover [Fe(Htrz)<sub>2</sub>(trz)](BF<sub>4</sub>) coordination polymer is reported. The synthesis relies on a two-step approach consisting on a partial surface ligand substitution of the citrate-stabilized Au NPs followed by the controlled growth of a very thin layer of the SCO polymer. As a result, colloidally stable core@shell spherical NPs of 19 nm in size exhibiting a narrow distribution in sizes have been obtained, revealing a switchable SCOshell of <i>ca.</i>4 nm. Temperature-dependent charge transport measurements of an electri…