Search results for "Thermal"
showing 10 items of 3576 documents
Surface pattern recording in Sb2Se3 thin films
2013
Abstract Results on the modification of Sb 2 Se 3 thin film surface topology by irradiation followed by wet-etching are given. Comparison of study results revealed the possible role of purely electronic and thermal processes in the relief formation. The latter is supposed to be connected with radiation-induced defect creation, free volume increase under the increased fluidity conditions as well as with the possible additional influence of electrostatic forces and stress. Changes in surface characteristics are presented and potential applications of this treatment are discussed.
Properties-morphology relationships in electrospun mats based on polylactic acid and graphene nanoplatelets
2018
Abstract Aligned and randomly oriented polylactic acid (PLA) biocomposite nanofiber mats filled with Graphene nanoplatelets (GnP) were prepared by electrospinning. The morphological analysis revealed the successful alignment of the fibers achieved by collecting the mats on a high-speed rotary drum. Furthermore, GnP addition on the polymeric solution leads to an increase of the viscosity with a consequent increment of the fiber diameter. Tensile tests demonstrated that the reinforcing effect of GnP when added to the PLA matrix was more than three times higher in the aligned systems if compared with the respective randomly oriented mats. DSC analysis showed that GnPs were able to slightly inc…
On the Finite Element Simulation of Secondary Operations on Metallic Foams
2007
Metallic foams have been recently introduced also as industrial materials due to their well known advantages. In fact, their low mass in conjunction with the good thermal and mechanical properties push toward an extensive diffusion in manufacturing industry. In the study here addressed, a very accurate investigation concerning the latter two aspects has been carried out. In fact, a secondary manufacturing process, i.e. the foam bending, has been taken into account. Anyway, all the knowledge derived for sheet metal bending is not directly applicable to the foams. A finite element code has been utilized for modeling the foam behavior during the bending processes and an accurate material rheol…
Folic acid-functionalized graphene oxide nanosheets via plasma etching as a platform to combine NIR anticancer phototherapy and targeted drug deliver…
2020
PEGylated graphene oxide (GO) has shown potential as NIR converting agent to produce local heat useful in breast cancer therapy, since its suitable photothermal conversion, high stability in physiological fluids, biocompatibility and huge specific surface. GO is an appealing nanomaterial for potential clinical applications combining drug delivery and photothermal therapy in a single nano-device capable of specifically targeting breast cancer cells. However, native GO sheets have large dimensions (0.5-5 mu m) such that tumor accumulation after a systemic administration is usually precluded. Herein, we report a step-by-step synthesis of folic acid-functionalized PEGylated GO, henceforth named…
Viscoelastic Behavior of an Epoxy Resin Modified with Recycled Waste Particles Analyzed through a Fractional Model
2021
It is well-known that the addition of randomly dispersed particles in polymers influences their linear viscoelastic behavior and dynamic mechanical properties. The aim of this study was to describe the viscoelastic behavior of an epoxy resin modified by waste glass and rubber particles using the linear fractional spring-pot model. Unlike complex classical exponential models, fractional models, being only two-parameter dependent, make it easier to characterize the viscoelastic behavior of materials. Isothermal relaxation and single frequency sweep temperature dynamic tests were carried out in a dynamic mechanical analyzer DMA150 by varying the content of the particles from 0 to 20% by weight…
Biopolymer-Targeted Adsorption onto Halloysite Nanotubes in Aqueous Media.
2017
Studies on the adsorption of biopolymers onto halloysite nanotubes (HNTs) in water were conducted. Three polymers with different charges-anionic (pectin), neutral (hydroxypropyl cellulose), and cationic (chitosan)-were chosen. The thermodynamic parameters for the adsorption of polymers onto the HNT surface were determined by isothermal titration calorimetry (ITC). The experimental data were interpreted based on a Langmuir adsorption model. The standard variations in free energy, enthalpy, and entropy of the process were obtained and discussed. Turbidimetry was used to evaluate the stability of functionalized nanoparticles in water. The ζ-potential clarified the surface charge properties of …
11B-MAS NMR approach to the boron adsorption mechanism on a glucose-functionalised mesoporous silica matrix
2018
[EN] Boron chemistry has raised much interest because, despite the difference between necessities and toxicity being very narrow, it is still widely used in industrial processes. In a previous work we reported an adsorbent for boron extraction from water by the functionalisation of a UVM-7 mesoporous silica matrix with gluconamide moieties. The ability of this material to adsorb boron is based on its well-known affinity for coordinating the cis-diols present in attached saccharide. Although much research on the formation of boron esters with sugars and sugar derivatives in solution has been done, very few reports have dealt with the adsorption mechanism of boron onto functionalised material…
Brookite, the Least Known TiO2 Photocatalyst
2013
Brookite is the least studied TiO2 photocatalyst due to the difficulties usually encountered in order to obtain it as a pure phase. In this review, a comprehensive survey of the different methods available for preparing brookite powders and films is reported. Attention has been paid both to the most traditional methods, such as hydrothermal processes at high temperatures and pressures, and to environmentally benign syntheses using water soluble compounds and water as the solvent. Papers reporting the photocatalytic activity of pure and brookite-based samples have been reviewed.
Design of a reactor operating in supercritical water conditions using CFD simulations. Examples of synthesized nanomaterials
2011
International audience; Direct information about fluids under supercritical water conditions is unfeasible due to the engineering restrictions at high pressure and high temperature. Numerical investigations based on computational fluid dynamics (CFD) calculations are widely used in order to get extensive information on the fluid behavior, particularly to help the design of a new reactor. This paper presents the numerical investigations performed on an original supercritical water device, especially in the level of the reactor. CFD calculations allow to design and optimize the present reactor described in this study. Currently, this process produces some nanometric oxide powders in continuou…
Visible photothermal deflection spectroscopy using microcantilevers
2012
International audience; Photothermal deflection spectroscopy based on bi-material cantilevers combines the sensitivity of miniature sensors and the selectivity of optical spectroscopy. In this paper, we report on the photothermal response of the microcantilevers functionalized with nanometer thin organic films in the visible region. Unlike responses in the infrared regime, in the optical region, light absorption by all the cantilever constituents must be considered for extraction of the physical parameters of the organic layer. A model of photothermal deflection for the optical region has been developed for two absorbing layers consisting of a thick metal (>200 nm) and a thin organic film. …