Search results for " TGA"
showing 10 items of 14 documents
Systematic Synthesis and Properties Evaluation of Dicationic Ionic Liquids, and a Glance Into a Potential New Field
2018
Dicationic ionic liquids (DILs), a subset of the ionic liquid (IL) family, have attracted growing interest in recent years, and the range of applications within which they are investigated is constantly expanding. However, data which allows structure to property correlation of a DIL is still limited, and thus selecting an appropriate salt to address a specific challenge can be problematic. In comparison to traditional ILs, DILs physico-chemical properties can be tuned by changing the length and type of spacer which connects the cationic heads as well as the type of cation. This in turn could give rise to symmetrical or asymmetrical DILs. In this work, a systematic study of a homogeneous cla…
Olive mill wastewaters decontamination based on organo-nano-clay composites
2019
Abstract Green composites for environmental applications were successfully prepared by intercalation of the biosurfactant Quillaja saponin onto montmorillonite mineral clay on varying pH and surfactant/clay ratio. Equilibrium adsorption isotherms were constructed and the system was characterized by performing TGA and XRD analyses. The efficiency of the surfactant-modified clay in the removal of the organic content present in olive mill wastewaters (OMW) was evaluated by means of spectrophotometric measurements. The interest for this cogent issue comes from the consideration that, despite their high pollutant content, OMW can be considered as a potential resource of several organic compounds…
Solution and thermal behaviour of novel dicationic imidazolium ionic liquids
2013
A new class of functionalised dicationic ionic liquids, containing a central cationic unit capped by a basic functionality (imidazole), has been synthesised. These salts have been characterised in isotropic solution using proton and 2D-NMR spectroscopy, and their thermal stability has been studied by DSC and TGA. All these novel salts contain the 1-(1-imidazolylmethyl)-3,5-di{1-(3'-octylimidazolylmethyl)}-benzene cation as a defining structural motif. Salts of both singly and doubly charged anions were prepared and, in particular, the selected monoanions (Br(-), [BF4](-), or [NTf2](-)) differ in size, shape and hydrogen-bonding ability, whereas the dianions differ in the nature of the space…
NMR Spectroscopic characterization and thermal behaviour of a new class of dicationic imidazolium ionic liquids
Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids
2014
Thermogravimetric analysis. A tool to evaluate the ability of mixtures in consolidating waterlogged archaeological woods
2010
Waterlogged archaeological woods (Pinus pinaster, Ulmus cf. minor and Fagus sylvatica L.) were consolidated by using Colophony, Rosin 100, and a mixture of Poly(ethylene) glycol (PEG) 3000 and Poly(propylene) glycol (PPG) 425. The efficiency of the consolidants was estimated by determining the content entrapped into the cavity of degraded wood. For this purpose, thermogravimetry was demonstrated to be a reliable tool. In the case that the polymeric mixture was used for impregnation, it was also possible to discriminate the amount of PEG 3000 from that of PPG 425 captured by the wood capillaries. Regardless of the wood nature, all the consolidants were present in treated samples in large amo…
Thermo-oxidative ageing of an organo-modified clay and effects on the properties of PA6 based nanocomposites
2013
a b s t r a c t In this work a careful investigation on the degradation of an organically modified montmorillonite sample (Cloisite 15A) thermal treated under different atmospheres, namely nitrogen, air and oxygen enriched atmosphere was performed. The exposure time of the thermal treatment ranged between 5 and 300 min. The chemical composition evolution as function of the thermal treatment conditions of the clay organic modifier was monitored by means of combined thermogravimetry/Fourier transform infrared spectroscopy (TGA-FTIR). Moreover, the morphological behaviour of treated Cloisite 15A sam- ples as function of the time and of the decomposition atmosphere was investigated by X-ray dif…
Structural Characterisation of Complex Layered Double Hydroxides and TGA-GC-MS Study on Thermal Response and Carbonate Contamination in Nitrate- and …
2015
Layered double hydroxides (LDHs) are versatile materials used for intercalating bioactive molecules in the fields of pharmaceuticals, nutraceuticals and cosmetics, with the purpose of protecting them from degradation, enhancing their water solubility to increase bioavailability and improving their pharmacokinetic properties and formulation stability. Moreover, LDHs are used in various technological applications to improve stability and processability. The crystal chemistry of hydrotalcite-like compounds was investigated by X-ray powder diffraction (XRPD), automated electron diffraction tomography (ADT) and thermogravimetric analysis (TGA)-GC-MS to shed light on the mechanisms involved in io…
Kriptovalūtu volatilitātes modelēšana un prognozēšana
2018
Maģistra darbā ir veikta GARCH volatilitātes modelēšana četrām, pēc tirgus kapitalizācijas, lielākajām kriptovalūtām: Bitcoin, Ethereum, Litecoin un Ripple. Darba empīriskajā daļā, tiek veikta kriptovalūtu GARCH, TGARCH, EGARCH un PGARCH modelēšana un prognozēšana izmantojot normālo un stjūdenta t sadalījumus, aplūkojot laika periodu no 07.08.2015 līdz 27.03.2018. Labākais modelis tiek noteikts salīdzinot trīs modeļu informācijas kritērijus un modeļu prognozes novērtējumus. Kaut arī stjūdenta t sadalījuma izmantošana uzlaboja modeļu novērtējumu visām četrām kriptovalūtām, tomēr tas ne vienmēr uzlaboja modeļa prognozi. Pēc iegūtajiem rezultātiem var secināt Ripple un Bitcoin EGARCH modeļi pā…
Effects of pyrolysis conditions on the thermal transformation of chicken manure into char
2012
Biochar is a fine-grained and highly porous carbonaceous substance, arising from the pyrolitic decomposition of natural or synthetic organic materials. It is lately applied to soils to favorably affect soil physico-chemical properties, such as water and nutrient retention and cation exchange capacity (CEC). The extent of the effect of biochar on crop productivity is very variable due to the different biophysical interactions and processes that occur when it is applied to soils. Char properties are greatly influenced by both natures of feedstock and process conditions. An accurate characterization of biochar is crucial to evaluate the possibility to amend soil with such material by avoiding …