Search results for "Thermogravimetric analysi"
showing 10 items of 213 documents
Dispersion of titanate nanotubes for nanomedicine: comparison of PEI and PEG nanohybrids.
2014
In the present study, we report the dispersion of titanate nanotubes (TiONts) via polymer grafting (PolyEthylene Glycol, PEG) or polymer adsorption (polyethylene imine, PEI) where different TiONts/polymer ratios have been investigated. The TiONts/PEI and TiONts/PEG nanohybrids were characterized by scanning and transmission electron microscopy as well as by zeta potential measurements in order to determine both their dispersion state and stability in water (at different pH for zetametry). The nature of the chemical bonds at the surface of these nanohybrids was investigated by Fourier-transformed infrared (FTIR) spectroscopy while the grafting densities of PEG on the nanotubes were quantifie…
The effect of silica nanoparticles on the morphology, mechanical properties and thermal degradation kinetics of PMMA
2012
Abstract Silica–PMMA nanocomposites with different silica quantities were prepared by a melt compounding method. The effect of silica amount, in the range 1–5 wt.%, on the morphology, mechanical properties and thermal degradation kinetics of PMMA was investigated by means of transmission electron microscopy (TEM), X-ray diffractometry (XRD), dynamic mechanical analysis (DMA), thermogravimetric analyses (TGA), Fourier-transform infrared spectroscopy (FTIR), 13 C cross-polarization magic-angle spinning nuclear magnetic resonance spectroscopy ( 13 C{ 1 H} CP-MAS NMR) and measures of proton spin-lattice relaxation time in the rotating frame ( T 1 ρ ( H )), in the laboratory frame ( T 1 ( H )) a…
Cyclodextrin–calixarene co-polymers as a new class of nanosponges
2014
Hyper-reticulated co-polymers jointly formed by cyclodextrin and calixarene units, which can be considered as a new class of nanosponges, were easily obtained by means of a click chemistry approach. In particular, we succeeded in preparing our materials by exploiting the copper-catalyzed 1,3-dipolar cycloaddition (CuAAC) reaction between heptakis-(6-deoxy)-(6-azido)-beta-cyclodextrin and (5,11,17,23-tetra-tert-butyl)-(25,26,27,28-tetra-propargyloxy)-calix-[4]-arene, mixed in different proportions. These materials were fully characterized by means of combined FT-IR, thermogravimetric, C-13 {H-1} CP-MAS NMR and nitrogen adsorption/desorption techniques. In particular, C-13 {H-1} CP-MAS spectr…
Thermal decomposition study of major refuse derived fuel components
2018
Abstract Refuse Derived Fuel (RDF) composed on biomass, paper, textiles, wood, synthetic polymers and other combustible materials is an alternative energy resource to implement Waste-to-Energy strategy. The aim of this study is to investigate the thermal decomposition characteristics of materials forming RDF by thermogravimetric analysis. Thermogravimetric (TG) analysis of RDF components demonstrates major differences in processes behind the thermal decomposition processes of waste components. Biomass decomposition can be divided into two distinct stages for wood, cotton, cotton wool and other biomass samples whereas three distinct stages can be distinguished for cardboard and paper samples…
Synthesis and characterization of bisulfonated poly(vinyl alcohol)/graphene oxide composite membranes with improved proton exchange capabilities
2020
Abstract Composite membranes based on poly(vinyl alcohol) (PVA) and graphene oxide (GO) were prepared by solution-casting method to be used as proton exchange membranes (PEMs) in fuel cell (FC) applications. Bisulfonation was employed as a strategy to enhance the proton conductivity of these membranes. First, a direct sulfonation of the polymer matrix was accomplished by intra-sulfonation of the polymer matrix with propane sultone, followed by the inter-sulfonation of the polymer chains using sulfosuccinic acid (SSA) as a crosslinking agent. Furthermore, the addition of graphene oxide (GO) as inorganic filler was also evaluated to enhance the proton-conducting of the composite membranes. Th…
Polyethylene composites filled with n‐alkyl‐functionalized siloxane‐silsesquioxane resins and sol‐gel silicas
2019
High‐density polyethylene (HDPE) composites filled with silicon‐based fillers were prepared by melt blending. The use of non‐functionalized and n‐octyl‐functionalized siloxane‐silsesquioxane resins and the sol‐gel silicas as fillers allowed us to evaluate the influence of functionalization of the fillers on the properties of the composites. The melting and crystallization temperatures of the composites were found to be only slightly affected by the addition of the silicon‐based fillers. In turn, the crystallization degree values were increased, in particular for the materials containing non‐functionalized fillers. The free‐volume properties of the composites did not change significantly in …
Polyfurfuryl alcohol composite as adsorbent of polychlorinated biphenyls and pyrethroid insecticides
2007
Abstract Composites from furfuryl alcohol and silica gel were prepared in dichloromethane using trifluoroacetic acid as catalyst and characterized by means of thermogravimetric analysis, transmission electron microscopy and nitrogen adsorption–desorption isotherms. The polymer content in the composites ranged between 19.5% and 32.9%. The capability to adsorb polychlorinated biphenyls and pyrethroid insecticides was tested for composite samples containing different percentages of polymer. Pyrethroids are retained almost totally by composites containing around 24–33% of polymer, while recovery of PCBs close to 80% is obtained with all the composites. No selectivity between compounds of the sa…
Novel organo-modifier for thermally-stable polymer-layered silicate nanocomposites
2015
A new novel approach for the stabilisation of polymer-clay nanocomposites has been investigated based on reacting chemically an antioxidant function, a hindered phenol moiety, with an organic modifier based on a quaternary ammonium salt. The chemically linked antioxidant-containing organic modifier (AO-OM) was then introduced into natural montmorillonite (MMt) through a cation-exchange reaction resulting in antioxidant-containing organo-modified clay (AO-OM-MMt). The new antioxidant-containing modified clay, along with other organo-modified clays having a similar organo-modifier but without the reacted antioxidant, were characterised by spectroscopic, thermogravimetric and x-ray diffraction…
Organic matter and wettability characteristics of wildfire ash from Mediterranean conifer forests
2015
Abstract Thermogravimetric analysis (TGA) and water repellency (wettability) determination of ash samples collected following wildfires at four different Mediterranean conifer forest sites in eastern Spain were conducted to provide insights into variations in key chemical and physical characteristics of ash. TGA allowed the evaluation of organic matter (OM) and inorganic carbonate (IC) characteristics and their role in ash wettability. Thermogravimetric profiles were recorded for 40 ash samples (ten from each site). The persistence of water repellency of all ash samples was assessed by the Water Drop Penetration Time (WDPT) test. OM contents decreased, whilst OM stability indices and IC con…
Influence of Biomass Combustion Products on Element Content and Thermal Stability of Latvian Sheep Breed Wool Filter Fibres
2020
Sheep wool is natural, easy obtainable, renewable and biodegradable material with a perspective application as a sorbent in filters for purification of industrial emissions from various environmental pollutants. The element content and thermal stability of Latvian dark-headed sheep wool filter fibres was analysed and described before and after exposure to biomass combustion products. Based on the obtained results, it is concluded that the sheep wool filter fibres can sorb various gaseous combustion products, such as carbon monoxide (CO), carbon dioxide (CO2) and nitrogen oxides (NOx), however, the sorption processes of these gases are irreversible. The obtained results of total reflection X…