scholarly journals Thermal analysis on potential risk of cosmetic materials by DSC

2018 ◽  
Vol 169 ◽  
pp. 01009
Author(s):  
Yi-Feng Chen ◽  
An-Chi Huang ◽  
Chung-Fu Huang ◽  
Chi-Min Shu
Keyword(s):  
Activation Energy ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Iron Oxide ◽  
Silicon Dioxide ◽  
Copper Oxide ◽  
Apparent Activation Energy ◽  
Potential Risk ◽  
Potential Hazard ◽  
Scanning Calorimetry

To explore the potential risk of usage on daily chemicals, the product which most contact for human directly, cosmetics, were selected as study object. In this study, common cosmetic materials, such as propylene glycol, ethanolamine, silicon dioxide, iron oxide, and copper oxide were discussed for potential hazard. According to results of differential scanning calorimetry experiments, the apparent activation energy and SADT were calculated out as 779.22 kJ mol-1 and 45°C, respectively.

scholarly journals Voltammetric monitoring of a solid-liquid phase transition in N,N,N′,N′-tetraoctyl-2,6-diamino-9,10-anthraquinone (TODAQ)

2019 ◽  
Vol 24 (1) ◽  
pp. 11-16
Author(s):  
Sunyhik Ahn ◽  
Thomas R. Forder ◽  
Matthew D. Jones ◽  
Richard A. R. Blackburn ◽  
Paul S. Fordred ◽  
...  
Keyword(s):  
Phase Transition ◽  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Liquid Phase ◽  
Apparent Activation Energy ◽  
Electrode Surface ◽  
Scanning Calorimetry ◽  
Liquid Phase Transition ◽  
Midpoint Potential ◽  
Solid Liquid

AbstractExploratory experiments on effects from a phase transition are reported for a low-melting microcrystalline anthraquinone (N,N,N′,N′-tetraoctyl-2,6-diamino-9,10-anthraquinone or TODAQ). Data for the solid-liquid phase transition are obtained by differential scanning calorimetry and then compared to data obtained by voltammetry. In preliminary electrochemical measurements, microcrystal deposits on a basal plane pyrolytic graphite electrode are shown to undergo a solid-state 2-electron 2-proton reduction in contact to aqueous 0.1 M HClO4 with a midpoint potential Emid,solid = − 0.24 V vs. SCE. The reduction mechanism is proposed to be limited mainly by the triple phase boundary line and some transport of TODAQ molecules towards the electrode surface for both solid and melt. A change in the apparent activation energy for this reduction is observed at 69 °C, leading to an enhanced increase in reduction current with midpoint potential Emid,liquid = − 0.36 V vs. SCE. A change of TODAQ transport along the crystal surface for solid microcrystalline material (for the solid) to diffusion within molten microdroplets (for the liquid) is proposed. Upon cooling, a transition at 60 °C back to a higher apparent activation energy is seen consistent with re-solidification of the molten phase at the electrode surface. Differential scanning calorimetry data for solid TODAQ dry and for TODAQ in contact to aqueous 0.1 M HClO4 confirm these transitions.

SURFACE AND VOLUME CRYSTALLIZATION OF METALLIC GLASS (Ni50Zr50)99.9P0.1 AS INVESTIGATED BY EXOELECTRON EMISSION (EEE) AND DIFFERENTIAL THERMAL ANALYSIS (DTA)

2002 ◽  
Vol 16 (03) ◽  
pp. 87-92 ◽  
Author(s):  
CZ. GÓRECKI ◽  
T. GÓRECKI ◽  
S. SZYMURA
Keyword(s):  
Activation Energy ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Differential Thermal Analysis ◽  
Metallic Glass ◽  
Heating Rate ◽  
Surface Crystallization ◽  
Exoelectron Emission ◽  
Ozawa Method ◽  
Scanning Calorimetry

Surface and volume crystallization of amorphous, melt-quenched (Ni50Zr50)99.9P0.1 alloy has been investigated by measurements of the temperature dependencies of the intensity of photostimulated exoelectron emission (EEE) and by differential scanning calorimetry (DSC). A comparison of these dependencies enables one to assess the tendency of the investigated materials to premature surface crystallization. For the (Ni50Zr50)99.9P0.1 alloy the surface crystallization occurs at temperatures distinctly lower than that for the crystallization in bulk. The activation energy for the surface crystallization, determined by the Ozawa method, i.e. from the shift of EEE peak corresponding to the surface crystallization on changing the heating rate, is also much lower than that for the volume crystallization.

scholarly journals Thermal analysis: basic concept of differential scanning calorimetry and thermogravimetry for beginners

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nurul Fatahah Asyqin Zainal ◽  
Jean Marc Saiter ◽  
Suhaila Idayu Abdul Halim ◽  
Romain Lucas ◽  
Chin Han Chan
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Commercial Application ◽  
Scanning Calorimetry ◽  
Teaching Activities ◽  
Sample Decomposition ◽  
Calibration Baseline

AbstractWe present an overview for the basic fundamental of thermal analysis, which is applicable for educational purposes, especially for lecturers at the universities, who may refer to the articles as the references to “teach” or to “lecture” to final year project students or young researchers who are working on their postgraduate projects. Description of basic instrumentation [i.e. differential scanning calorimetry (DSC) and thermogravimetry (TGA)] covers from what we should know about the instrument, calibration, baseline and samples’ signal. We also provide the step-by-step guides for the estimation of the glass transition temperature after DSC as well as examples and exercises are included, which are applicable for teaching activities. Glass transition temperature is an important property for commercial application of a polymeric material, e.g. packaging, automotive, etc. TGA is also highlighted where the analysis gives important thermal degradation information of a material to avoid sample decomposition during the DSC measurement. The step-by-step guides of the estimation of the activation energy after TGA based on Hoffman’s Arrhenius-like relationship are also provided.

scholarly journals Combined thermal analysis of plant oils

2021 ◽  
Author(s):  
Kinga Tamási ◽  
Kálmán Marossy
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Low Temperature ◽  
Glassy State ◽  
Mechanical Analysis ◽  
Plant Oils ◽  
Scanning Calorimetry ◽  
Natural Plant ◽  
The Moment ◽  
Current Reversal

AbstractThe paper deals with the study of seven selected natural plant oils. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and thermally stimulated discharge (TSD) methods were used. It has been found that most of the oils tested are in a glassy state at low temperature and have multiple transitions in the low temperature range. DSC shows complex melting-like processes or glass transition. For both DMA and TSD, the scaffold supportive method was used and found as a suitable one. DMA and TSD proved more sensitive than DSC and revealed at least two transitions between − 120 and − 40 °C. In the case of three oils (argan, avocado and sunflower), current reversal was observed by TSD; this symptom cannot be fully explained at the moment.

scholarly journals Films Based on a Blend of PVC with Copolymer of 3-Hydroxybutyrate with 3-Hydroxyhexanoate

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 270
Author(s):  
Evgeniy V. Belukhichev ◽  
Vera E. Sitnikova ◽  
Evgenia O. Samuylova ◽  
Mayya V. Uspenskaya ◽  
Daria M. Martynova
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Environmental Pollution ◽  
Polyvinyl Chloride ◽  
Polymer Films ◽  
Thermomechanical Analysis ◽  
Packaging Materials ◽  
Packaging Film ◽  
Scanning Calorimetry ◽  
Environmental Friendliness

Polymeric packaging materials are one of the factors of environmental pollution. Reducing the environmental burden is possible by increasing the environmental friendliness of packaging materials. In this work, we study polymer films based on polyvinyl chloride (PVC) with a copolymer of 3-hydroxybutyrate with 3-hydroxyhexanoate P (3-GB) (3-GG) with different component ratios. The process of processing blends in the process of obtaining a packaging film is considered. The optical characteristics of the obtained films are determined. Thermal analysis of the obtained films was carried out using the differential scanning calorimetry (DSC), TGA, and thermomechanical analysis (TMA) methods. The degree of gelling of the resulting mixture was determined. It is shown that PHB has miscibility with PVC.

Human cytokines characterized by dielectric thermal analysis, thermogravimetry, and differential scanning calorimetry

2012 ◽  
Vol 111 (3) ◽  
pp. 1707-1716 ◽  
Author(s):  
Salaam Saleh ◽  
Druthiman Reddy Mantheni ◽  
Manik Pavan Kumar Maheswaram ◽  
Susan Moreno-Molek ◽  
Tobili Sam-Yellowe ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Scanning Calorimetry ◽  
Dielectric Thermal Analysis ◽  
Human Cytokines

Thermal Analysis of Aluminum Alloys

2019 ◽  
Author(s):  
Daniel Larouche
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Quality Control ◽  
Aluminum Alloys ◽  
Isothermal Calorimetry ◽  
Curve Analysis ◽  
Cooling Curve ◽  
Scanning Calorimetry ◽  
Cooling Curve Analysis ◽  
Scientists And Engineers

Thermal analysis is applied on aluminum alloys by researchers to investigate mainly phase transformations, while it is regularly used for quality control purposes in industry. Techniques like cooling curve analysis, differential thermal analysis, differential scanning calorimetry, and isothermal calorimetry are amongst those most frequently used by scientists and engineers. These techniques will be described, and a mathematical description of the results will be developed. State-of-the-art quantification methods applied on aluminum alloys will be presented and criticized based on specific examples taken from the literature.

scholarly journals A thermal degradation study of Y and La methanesulfonates

2006 ◽  
Vol 71 (8-9) ◽  
pp. 905-915
Author(s):  
Moura de ◽  
Jivaldo Matos ◽  
Farias de
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Differential Thermal Analysis ◽  
Thermal Degradation ◽  
Degradation Process ◽  
Oxide Formation ◽  
Scanning Calorimetry ◽  
Degradation Study ◽  
Thermogravimetric Data ◽  
Thermal Degradation Process

The synthesis, characterization and thermal degradation of yttrium and lanthanum methanesulfonates is reported. The prepared salts were characterized by elemental analysis and infrared spectroscopy. The thermal degradation study was performed using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC).Using the thermogravimetric data, a kinetic study of the dehydration ofY and Lamethanesulfonates was performed employing the Coats-Redfern and Zsak?methods. It was verified that under heating, yttrium and lanthanum methanesulfonates undergo three main processes: dehydration, thermal degradation and oxide formation. Furthermore, depending on the nature of the atmosphere, i.e., inert or oxidant, the thermal degradation process could be endothermic (N2) or exothermic (air).

scholarly journals Thermal stability and thermal decomposition of sucralose

2018 ◽  
Vol 39 (4) ◽  
pp. 21
Author(s):  
Gilbert Bannach ◽  
Rafael R. Almeida ◽  
Luis G. Lacerda ◽  
Egon Schnitzler ◽  
Massao Ionashiro
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Differential Thermal Analysis ◽  
Infrared Spectroscopy ◽  
Scanning Calorimetry ◽  
Thermoanalytical Techniques ◽  
Thermal Stability Of

Several papers have been described on the thermal stability of the sweetener, C12H19Cl3O8 (Sucralose). Nevertheless no study using thermoanalytical techniques was found in the literature. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC) and infrared spectroscopy, have been used to study the thermal stability and thermal decomposition of sweetener.

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