Probing Water Mobility in Human Dentine with Neutron Spectroscopy

The aim of this study was to investigate hydrogen mobility within innate and demineralized human dentine. Dentine sections from extracted human molars, demineralized or not, were analyzed by combining neutron spectroscopy with thermal analysis. For the thermal analysis of the samples, differential scanning calorimetry and thermal gravimetric analysis, coupled with Fourier transform infrared spectroscopy, were performed. The hydrogen dynamics of water, collagen, and hydroxyl groups present in the samples were investigated via neutron spectroscopy. From the mass loss observed from the thermogravimetric analysis curves up to 600 °C, the same amount of organic content is identified in the samples. From the differential scanning calorimetry curves, a higher change in enthalpy associated with the denaturation of collagen is registered in the demineralized dentine; that is, a structural change occurs in the collagen subsequent to demineralization. Since the intensity measured by neutron spectroscopy is dominated by the signal from hydrogen, in our samples—coming mostly from the bulk-like and loosely bound water as well as from the collagen itself—higher proton mobility within the demineralized dentine was detected when compared with innate dentine. In the demineralized dentine, this proton mobility amounts to 80%, while the remaining hydrogen accounts for a combination of 1) structural hydroxyls, as a result of the incomplete dissolution of the mineral phase by acid etching, and 2) hydrogen tightly bound in the collagen structure. By combining neutron spectroscopy with the calorimetry data, our findings support the idea that hydroxyapatite protects the collagen in innate dentine. Demineralized dentine, however, acts as a sponge where free bulk-like water is trapped.

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Characterisation of Hydroxyapatite/Bacterial Cellulose Nanocomposites

Polymers and Polymer Composites ◽

10.1177/096739110901700602 ◽

2009 ◽

Vol 17 (6) ◽

pp. 353-358 ◽

Cited By ~ 7

Author(s):

Shengnan Zhang ◽

Guangyao Xiong ◽

Fang He ◽

Yuan Huang ◽

Yulin Wang ◽

...

Keyword(s):

Differential Scanning Calorimetry ◽

Bacterial Cellulose ◽

Photoelectron Spectroscopy ◽

Thermo Gravimetric Analysis ◽

Hydroxyl Groups ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Selected Area Electron Diffraction ◽

Transmission Electron ◽

Cellulose Nanocomposites

A novel nanocomposite material consisting of hydroxyapatite (HAp) deposited on a phosphorylated bacterial cellulose (BC) has been synthesised via a biomimetic route. X-ray photoelectron spectroscopy (XPS) showed that phosphate groups were successfully introduced to the hydroxyl groups of BC by phosphorylation reaction to promote the growth of calcium phosphate. Transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED) patterns of HAp/BC demonstrated that HAp crystals wrap the surfaces of BC fibres. In this work, HAp/BC nanocomposites were studied using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The TGA result suggested that HAp/BC nanocomposite, similar to natural bone in terms of composition, contained carbonate ions, in agreement with our previous Fourier transform infrared (FTIR) spectroscopy results. Thermal behaviour differences between BC and HAp/BC were observed by differential scanning calorimetry (DSC). The thermal stability of HAp/BC obtained from DSC showed an improvement when compared to that of a pure BC sample.

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Thermal analysis of Li2-хNaxGe4O9 glasses crystallization

Journal of Physics and Electronics ◽

10.15421/332025 ◽

2020 ◽

Vol 28 (2) ◽

pp. 83-86

Author(s):

A. O. Diachenko ◽

D. V. Volynets ◽

M. P. Trubitsyn ◽

M. D. Volnianskii

Keyword(s):

Thermal Analysis ◽

Solid Solution ◽

Differential Scanning Calorimetry ◽

Thermal Gravimetric Analysis ◽

Single Stage ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Glass Crystallization ◽

Scanning Calorimetry ◽

Dsc Measurements

The glasses of lithium-sodium tetragermanate LiNaGe4O9 and solid solution Li1.8Na0.2Ge4O9 were prepared by quenching the melt and crystallized on heating. The glass crystallization was controlled by differential scanning calorimetry and thermal gravimetric analysis. The DSC measurements performed in the range 300–1200 K show that the crystallization of the glasses occurs through a single stage. There are no anomalies on TGA dependences. It is assumed that LiNaGe4O9 and Li 1.8Na0.2Ge4O9 glasses crystallize in accordance with a polymorphic mechanism.

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Staling of sponge cakes with added emulsifiers

Progress in Agricultural Engineering Sciences ◽

10.1556/446.2020.20012 ◽

2020 ◽

Author(s):

Maria Marudova ◽

Stanko Stankov ◽

Marianna Baeva

Keyword(s):

Thermal Analysis ◽

Differential Scanning Calorimetry ◽

Differential Thermal Analysis ◽

Control Sample ◽

Bound Water ◽

Storage Period ◽

Scanning Calorimetry ◽

Retarding Effect ◽

Starch Retrogradation ◽

Endothermic Transition

AbstractThe effect of three types of emulsifiers (polyglycerol monostearate ester – E475, sucrose stearate ester – E473 and modified inulin palmitate ester – HP-25) on the starch retrogradation in sponge cake (SC) during storage was investigated. The method of differential scanning calorimetry (DSC) was applied to determine the changes in the starch retrogradation during the staling process. The retrogradation temperature and the enthalpy of the endothermic transition decreased when emulsifiers were added. The lowest values of the enthalpy for the whole storage period were found for SC with 1% HP-25. The methods of differential thermal analysis (DTA) and thermogravimetry analysis (TGA) showed significantly bigger (1.43 times) amount of strongly bound water in the crumb of the SC with E475 and HP-25 in comparison to the control sample on the sixth day of storage. Based on our results, emulsifiers possessed retarding effect on the starch retrogradation and extend the shelf-life of the SC.

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Studies on bismaleimides and related materials: Part III. Synthesis and characterization of bismaleimiides derived from benzophenone, 1, 2-diphenylethane, 1, 4-diphenylbutane and condensed pyrazines

High Performance Polymers ◽

10.1088/0954-0083/6/1/004 ◽

1994 ◽

Vol 6 (1) ◽

pp. 35-41

Author(s):

P N Prestont ◽

V K Shaht ◽

S W Simpsont ◽

I Soutar ◽

N J Stewart

Keyword(s):

Thermal Analysis ◽

Differential Scanning Calorimetry ◽

Oxidative Stability ◽

Thermal Gravimetric Analysis ◽

Dynamic Mechanical Thermal Analysis ◽

Synthesis And Characterization ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Scanning Calorimetry

New bismaleimides have been synthesised from diamines derived from benzophenone, 1,2-diphenylethane, 1,4-diphenylbutane, 2, 3-diphenylquinoxaline and 2, 3-diphenylnaphtho[2, 3-b]pyrazine. Cure profiles have been established by both differential scanning calorimetry (Dsc) and dynamic mechanical thermal analysis (DMTA). Cured resins prepared from the bismaleimide monomers were studied by thermal gravimetric analysis (TGA) with all materials exhibiting good thermal and thermo-oxidative stability.

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

Chemistry Teacher International ◽

10.1515/cti-2020-0010 ◽

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.

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Enhancement of Antioxidant and Hydrophobic Properties of Alginate via Aromatic Derivatization: Preparation, Characterization, and Evaluation

Polymers ◽

10.3390/polym13152575 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2575

Author(s):

Smaher M. Elbayomi ◽

Haili Wang ◽

Tamer M. Tamer ◽

Yezi You

Keyword(s):

Radical Scavenging Activity ◽

Radical Scavenging ◽

Hydroxyl Group ◽

Hydroxyl Groups ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Benzoyl Group ◽

Antioxidant Evaluation ◽

Thermo Stability

The preparation of bioactive polymeric molecules requires the attention of scientists as it has a potential function in biomedical applications. In the current study, functional substitution of alginate with a benzoyl group was prepared via coupling its hydroxyl group with benzoyl chloride. Fourier transform infrared spectroscopy indicated the characteristic peaks of aromatic C=C in alginate derivative at 1431 cm−1. HNMR analysis demonstrated the aromatic protons at 7.5 ppm assigned to benzoyl groups attached to alginate hydroxyl groups. Wetting analysis showed a decrease in hydrophilicity in the new alginate derivative. Differential scanning calorimetry and thermal gravimetric analysis showed that the designed aromatic alginate derivative demonstrated higher thermo-stability than alginates. The aromatic alginate derivative displayed high anti-inflammatory properties compared to alginate. Finally, the in vitro antioxidant evaluation of the aromatic alginate derivative showed a significant increase in free radical scavenging activity compared to neat alginate against DPPH (2,2-diphenyll-picrylhydrazyl) and ABTS free radicals. The obtained results proposed that the new alginate derivative could be employed for gene and drug delivery applications.

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Combined thermal analysis of plant oils

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-020-10470-y ◽

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.

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

Polymers ◽

10.3390/polym12020270 ◽

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.

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