scholarly journals Accelerated Ageing Procedures to Assess the Stability of an Unconventional Acrylic-Wax Polymeric Emulsion for Contemporary Art

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1925
Author(s):  
Francesca Caterina Izzo ◽  
Eleonora Balliana ◽  
Emanuela Perra ◽  
Elisabetta Zendri
Keyword(s):  
Gas Chromatography Mass Spectrometry ◽  
Accelerated Ageing ◽  
Scanning Calorimetry ◽  
Pyrolysis Gas ◽  
Aqueous Emulsion ◽  
Zinc White ◽  
Acrylic Copolymers ◽  
Ft Ir ◽  
The Stability ◽  
Contemporary Painting

This research evaluates the stability of an aqueous emulsion of acrylic copolymers and waxes. Edelwachs, generally applied on wood, has been recently used as an unconventional medium in contemporary painting. Through Pyrolysis–Gas Chromatography–Mass Spectrometry (Py-GC-MS) and Fourier Transformed Infrared Attenuated Total Reflectance (FT-IR-ATR) analyses, the composition of Edelwachs was defined as a mixture of acrylic polymers (MA, MMA, nBA, nBMA), Carnauba and microcrystalline waxes and additives. Mock-ups-obtained mixing Edelwachs with titanium white, zinc white and ultramarine blue were subjected to UV, high temperatures, and high relative humidity accelerated ageing. The effect of the ageing procedures was evaluated through optical microscopy, colourimetric measurements, FT-IR-ATR, Thermogravimetry and Differential Scanning Calorimetry (TG-DSC) and wettability measures. FT-IR-ATR spectra do not show significant variations in terms of chemical stability, indicating a fair stability of Edelwachs as a painting binder. UV and high temperature treatments show the most relevant effects in terms of colorimetric changes (increasing of b*) and thermal stability. The TG-DSC highlights the influence of the pigments (specifically zinc white) mainly on the thermal behaviour of the acrylates. The unexpected decrease of wettability of the paint films, registered after ageing, may indicate a possible phase separation among acrylates and waxes.

scholarly journals Novel P/Si Based Nanoparticles for Durable Flame Retardant Application on Cotton

2021 ◽  
Author(s):  
Na Li ◽  
Panpan Chen ◽  
Dongni Liu ◽  
Gaowei Kang ◽  
Liu Liu ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Oxygen Index ◽  
Dip Coating ◽  
Gas Chromatography Mass Spectrometry ◽  
Cotton Fibers ◽  
Pyrolysis Gas ◽  
Limiting Oxygen Index ◽  
Potential Safety ◽  
Ft Ir

Abstract Cotton fibers as original materials of cotton fabrics have a widely application due to its perfect hygroscopicity, air permeability and largest annual output. However, cotton materials have potential safety hazard during its application because of flammability (limiting oxygen index is about 18%). In order to improve the flame retardancy of cotton fibers and reduce the damage of its mechanical properties, novel P/Si based flame retardant (PFR) nanoparticles were synthesized by one-step radical polymerization. Vinyl phosphoric acid and tetramethyl divinyl disiloxane were introduced into the nanoparticles. The structure, morphology and thermal stability of PFR was characterized by fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis test (TGA). Durable flame retardant cotton fibers were prepared by dip-coating and plasma induced crosslinking methods. Micro-calorimeter (MCC) characterization showed that the peak of heat release rate (pHRR) and the total heat release were reduced by 47.3% and 29.8% for modified cotton fibers compared with pure cotton fibers. Limiting oxygen index (LOI) of modified cotton fibers was increased to 27%. The residue carbon of modified cotton fibers was 19.0% at 700 o C, while the value of pure cotton fibers was 3.0%. Besides, durability of the modified cotton fibers was approved by cyclic washing test. In addition, flame retardant mechanism was revealed by collecting and analyzing condensed and gaseous pyrolysis products. The data of FE-SEM for residue carbon, FT-IR spectra of products at different pyrolysis temperatures and pyrolysis gas chromatography mass spectrometry (Py-GC-MS) showed that PFR was a synergistic flame retardant contained barrier and quenching effecting applied on cotton materials.

scholarly journals Consequence of ANASTROZOLE on Chemo therapy

2017 ◽  
Vol 1 (2) ◽  
pp. 01-04
Author(s):  
Saritha Garrepalli
Keyword(s):  
Particle Size ◽  
In Vitro Release ◽  
Scanning Calorimetry ◽  
Ir Studies ◽  
Release Studies ◽  
Ft Ir ◽  
The Mean ◽  
Pure Drug ◽  
The Stability

Prepared nanoparticles were characterized in terms of particle size, scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). In-vitro release studies were performed in phosphate buffer saline pH 7.4 at 37˚±0.5˚C for 1month. The mean particle size of obtained nanoparticles was 150-400 nm and was apparently spherical in shape, with smooth surface. DSC is done for the stability test for pure drug and sample. The thermogram of drug has not shifted for in the formulation compare to pure drug thermogram hence, the stability of formulation is not changed. FT-IR studies demonstrated that the drug was not changed in the formulation during the fabrication process.The encapsulation efficiency was about 48%. The Anastrozole-BSA nanoparticles exhibit a most interesting release profile with small initial burst followed by slower and controlled release.

A Hydroxyapatite-Collagen Composite Useful to Make Bioresorbable Scaffolds for Bone Reconstruction

2010 ◽  
Vol 76 ◽  
pp. 133-138 ◽  
Author(s):  
Giulio D. Guerra ◽  
Caterina Cristallini ◽  
Elisabetta Rosellini ◽  
Niccoletta Barbani
Keyword(s):  
Weight Ratio ◽  
Average Diameter ◽  
Cross Linking ◽  
Bone Reconstruction ◽  
Scanning Calorimetry ◽  
Bioresorbable Scaffolds ◽  
Micro Particles ◽  
Ft Ir ◽  
The Cross ◽  
The Stability

Composites between hydroxyapatite (HA) and collagen (Col) may be used to make bioresorbable scaffolds for bone reconstruction. A suspension of micro-particles (average diameter ≅ 30 µm) of HA annealed at 1100°C in Col solution (80:20 HA to Col weight ratio) was manufactured in films by casting, and then some films were cross-linked by glutaraldehyde vapours. Cross-linked sponges were obtained by treating the suspension with transglutaminase, and by lyophilizing the so obtained gel. Characterization by scanning electron microscopy, water sorption test, Col release in water, thermogravimetric analysis and differential scanning calorimetry shows that the cross-linking enhances the stability of the composite. Conversely, neither the interactions between HA and Col, detected by spotlight FT-IR, nor the degradation by collagenase, which is a requirement for the bioresorbibility, are affected by the cross-linking.

scholarly journals DEVELOPMENT OF NANOEMULSION CONTAINING PELARGONIUM GRAVEOLENS OIL: CHARACTERIZATION AND STABILITY STUDY

2016 ◽  
Vol 8 (12) ◽  
pp. 271 ◽  
Author(s):  
Janice Luehring Giongo ◽  
Rodrigo De Almeida Vaucher ◽  
Aline Ourique ◽  
MÍriam Steffler ◽  
Clarissa Piccinin Frizzo ◽  
...  
Keyword(s):  
Particle Size ◽  
Storage Temperature ◽  
Thermo Gravimetric Analysis ◽  
Physicochemical Characteristics ◽  
Stability Study ◽  
Gas Chromatography Mass Spectrometry ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Different Temperatures ◽  
The Stability

<p><strong>Objective: </strong>To develop, characterize and evaluate the stability of nanoemulsions containing geranium oil (NEG) at different temperatures (4 °C, 25 °C and 45 °C) for 90 d.</p><p><strong>Methods: </strong>The quantification of oil in the nanostructure was performed by <a href="https://www.google.com.br/url?sa=t&amp;rct=j&amp;q=&amp;esrc=s&amp;source=web&amp;cd=1&amp;cad=rja&amp;uact=8&amp;ved=0ahUKEwiYjL3Niv7OAhVJI5AKHZ-_AeUQFggfMAA&amp;url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FGas_chromatography%25E2%2580%2593mass_spectrometry&amp;usg=AFQjCNE3N9EyqMTXtw7u0lxolSlnU5zJfQ">gas chromatography–mass spectrometry</a> (GC-MS). The NEG was prepared in Ultra-Turrex and characterized by determining the particle size, polydispersity indices and pH. The thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) to evaluate the thermal stability of the compounds, the thermal events and morphological analyses of NEG, respectively.<strong></strong></p><p><strong>Results: </strong>The results allow us to suggest that the use the ultra-turrax method is a strategy good to NEG preparation. The stability of the NEG was strongly influenced by storage temperature, with droplet size increasing rapidly at higher temperatures (45 °C), which was attributed to coalescence near the phase inversion temperature. The NEG submitted the low temperatures (4±2 °C) remained with the same particle size value (164 nm). However, the citronellol and geraniol showed a significant reduction throughout the test even in these conditions of temperature. Thermogram of NEG shows the crystallization peak at the cooling cycle in-20.1 °C and a melting was observed at 1.5 °C. TEM images indicated that NEG was spherical and nanometric.</p><p><strong>Conclusion: </strong>The proposed Ultra-Turrax method is simple which prevents volatilization of GO for the production of NEG. The formulations presented good physicochemical characteristics and stability for 90 d was only achieved in 4 °C.</p>

Synthesis of Carbon Nanotubes, and the Effect on Thermal Stability in High-Impact Polystyrene

2008 ◽  
Vol 61 (1) ◽  
pp. 72 ◽  
Author(s):  
Qinghong Kong ◽  
Junhao Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Degradation Mechanism ◽  
High Impact ◽  
Gas Chromatography Mass Spectrometry ◽  
Scanning Calorimetry ◽  
Pyrolysis Gas ◽  
High Impact Polystyrene ◽  
Synthesis Of Carbon Nanotubes ◽  
Better Than

Carbon nanotubes (CNTs) with diameters ranging from 40 to 100 nm have been synthesized by the solvothermal process using ethanol as a carbon source and LaNiO3 as catalyst. The synthesized CNTs can be used for filaments in high-impact polystyrene (HIPS). HIPS/CNT nanocomposites have been prepared by the melt–intercalation process. Thermogravimetric analysis and differential scanning calorimetry indicate that the thermal stability of HIPS/CNT nanocomposites is better than that of HIPS. The thermal degradation mechanism was investigated by pyrolysis gas chromatography mass spectrometry.

scholarly journals Active components in leaves of Rhus chinensis Mill.

2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1729-1735
Author(s):  
Chaofan Suo ◽  
Zhiyong Sun ◽  
Yaoming Wang ◽  
Shuaiwei Dong ◽  
Chunxia Lv ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Chemical Constituents ◽  
Gas Chromatography Mass Spectrometry ◽  
Active Components ◽  
Pyrolysis Gas ◽  
Economic Resource ◽  
Rhus Chinensis ◽  
Chromatography Mass Spectrometry ◽  
Ft Ir

Rhus chinensis Mill is a high-quality eco-economic resource for potential sustainable development. To analyze the chemical constituents of extracts from the leaves of Rhus chinensis Mill for resource values, the following analytical methods were performed: Fourier transform infrared (FT-IR) spectrum, gas chromatography-mass spectrometry (GC-MS), thermogravimetry, and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The results showed that the leaves of Rhus chinensis Mill were rich in volatile substances that could be exploited and used

scholarly journals Resource utilization of Sambucus williamsii Hance root

2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1697-1703
Author(s):  
Huiling Chen ◽  
Shuaiwei Dong ◽  
Zhiyong Sun ◽  
Yaoming Wang ◽  
Xuefeng Luo ◽  
...  
Keyword(s):  
Food Additives ◽  
Forest Products ◽  
Raw Material ◽  
Gas Chromatography Mass Spectrometry ◽  
Forest Resource ◽  
Energy Research ◽  
Pyrolysis Gas ◽  
Decomposition Products ◽  
Thermal Decomposition Products ◽  
Ft Ir

In recent years, more and more attention has been paid to bio-energy. People are eager to find new substances from sustainable forest products for energy research. As an important forest resource, Sambucus williamsii Hance has gradually attracted people?s attention. Therefore, in order to explore a new way of comprehensive utilization of Sambucus williamsii Hance, the root samples of Sambucus williamsii Hance were collected and extracted with ethanol, benzene/ethanol and methanol, respectively. Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TGA) and pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) were used to detect the treated samples, and various substances in Sambucus williamsii Hance root were studied in depth. The results show that the thermal decomposition products of raw material powders and extracts contain many chemical substances. Such as (1R) - (-) ?Myrtenal, D-Mannose, Furfural, O-Xylene, Phenol, 2,6-dimethyl-. These substances have broad application prospects in chemical industry, bio-medicine, food additives and other fields, thus providing a theoretical basis for the rational use of Sambucus williamsii Hance.

scholarly journals Induced Smectic Phases from Supramolecular H-Bonded Complexes Based on Non-Mesomorphic Components

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 940
Author(s):  
Fowzia S. Alamro ◽  
Hoda A. Ahmed ◽  
Magdi M. Naoum ◽  
Ayman M. Mostafa ◽  
Asmaa A. Alserehi
Keyword(s):  
Fatty Acids ◽  
Differential Scanning Calorimetry ◽  
Scanning Calorimetry ◽  
Acid Component ◽  
Smectic Phases ◽  
Ft Ir ◽  
The Stability ◽  
Oleic And Linoleic Acids ◽  
Ft Ir Spectroscopy ◽  
Induced Smectic Phases

New non-symmetrical 1:1 supramolecular H-bonded (SMHB) interactions, Ix/II, were designed between the non-mesomorphic fatty acids (palmitic, oleic and linoleic acids) and 4-tetradecyloxyphenylazo pyridine. Mesophase behaviors of the formed complexes were examined via differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). In order to confirm the H-bond interaction formations within the prepared SMHB complexes, FT-IR spectroscopy was established whereby Fermi bands confirm these interactions. Mesomorphic investigations for all complexes indicated that, independent of the terminal alkenyl chains of the natural acids, induced dimorphic smectic phases were observed. The stability of formed mesophases was found to depend on the degree of un-saturation of the terminal alkenyl group of acid component.

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