Effect of swift heavy ion irradiation on thermal, optical and structural properties of poly vinylidene chloride

Devgan, Kusum; Singh, Lakhwant

doi:10.1016/j.radmeas.2013.08.010

Cited by 15 publications

(5 citation statements)

References 28 publications

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“…However, it should be noted that the linear nature of the change in the optical density (absorbance) with an increase in the irradiation fluence above 5 × 10 12 ion/cm 2 indicates not only the cumulative effect of structural deformations that change the absorbing ability of ceramics due to the formation of defective inclusions and vacancy complexes but also a direct correlation between the absorption capacity and the deformation distortion of the crystal structure. In this case, the obtained dependences of the change in optical density are in good agreement with data from a number of studies in the literature in which the change in this value characterizes the relationship between structural distortions and the absorbing ability of a material [48][49][50].…”

Section: Establishing the Relationship Between Structural Distortions...supporting

confidence: 88%

Study of the Relationship between Changes in the Structural, Optical, and Strength Properties of AlN Ceramics Subjected to Irradiation with Heavy Xe23+ Ions

Bikhert,

Kozlovskiy,

Popov

et al. 2023

Materials

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The purpose of this study is to comprehensively analyze the influence of different fluences of irradiation with Xe23+ heavy ions on alterations in the structural, optical, and strength properties of AlN ceramics and to establish a connection between structural distortions and alterations in the optical and mechanical properties of the ceramics. X-ray diffraction, UV-Vis and Raman spectroscopy, and indentation and single-compression methods were used as research methods. During the study, it was demonstrated that at low irradiation fluences, the main role in the changes in the properties of the AlN ceramics is played by effects related to changes in their optical properties and a fundamental absorption edge shift, which characterizes changes in the electronic properties of the ceramics (changes in the distribution of electron density). A study of the variations in the optical properties of the examined samples in relation to the irradiation fluence showed that when the fluence surpasses 5 × 1011 ion/cm2, an extra-spectral absorption band emerges within the range of 3.38–3.40 eV. This band is distinctive for the creation of vacancy ON–VAl complexes within the damaged layer’s structure. The presence of these complexes signifies structural deformations and the accumulation of defective inclusions within the damaged layer. An analysis of changes in the parameters of the crystal lattice showed that structural distortions in the damaged layer are due to the accumulation of tensile residual mechanical stresses, an increase in the concentration of which leads to the swelling and destruction of the damaged layer. Some correlations between the mechanical properties of ceramics and the irradiation fluence indicate the ceramics’ remarkable resistance to radiation-induced brittleness and weakening. These effects become apparent only when structural damage accumulates, resulting in the swelling of the crystal lattice exceeding 2.5–3%.

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Section: Establishing the Relationship Between Structural Distortions...supporting

confidence: 88%

Study of the Relationship between Changes in the Structural, Optical, and Strength Properties of AlN Ceramics Subjected to Irradiation with Heavy Xe23+ Ions

Bikhert,

Kozlovskiy,

Popov

et al. 2023

Materials

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show abstract

“…[28,29] The purpose of the research was to improve the selectivity of VDC, so the catalytic cracking reaction process and the transition state were calculated and studied with the generated product VDC as the research object. [30,31] The vibrational frequencies were calculated for initial, transition and final states. Figure 8 showed the reaction pathway of 1,1,2-TCE dehydrochlorination with CsCl as catalyst.…”

Section: Catalytic Cracking Simulation Calculationmentioning

confidence: 99%

Investigation on Catalytic Cracking Performance of Metal Catalysts for 1,1,2‐TCE

Ge,

Zhao,

Yuan

et al. 2024

ChemistrySelect

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PVDC played an irreplaceable role in the field of sealed packaging, and its polymer monomer, VDC, was in short supply. At present, the saponification of 1,1,2‐TCE and sodium hydroxide was used to generate VDC in industry, which was a process with great environmental pollution. Catalytic dehydrochlorination of 1,1,2‐TCE to produce VDC was a green process route, but the selection of catalysts had always been controversial. This study aimed to screen catalysts suitable for industrial applications. The cesium based catalysts with good catalytic performance were systematically characterized and evaluated, and the overall reaction process was calculated using DFT calculation. The experimental results indicated that the cesium chloride catalyst with a 3 % molar fraction had the best catalytic performance, achieving 55.27 % conversion of 1,1,2‐TCE and 76.85 % selectivity for VDC, respectively. The reaction paths and transition state of several catalysts were calculated by DFT method. It was revealed that the activation energy required for the reaction of CsCl catalyst was the lowest, at 130.61 kcal/mol, and the energy of the product VDC was the lowest, at −63.25 kcal/mol, making it the most stable. The calculation results were consistent with the experimental data, indicating that cesium chloride catalyst had the best reaction performance. Therefore, the subsequent research could focus on the method of improving the supported dispersity of cesium chloride catalyst and the development of core‐shell catalyst to lay the foundation for further industrialization.

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“…Vinylidene chloride (VDC) was an organic polymer monomer . It could be copolymerized with other polymerization monomers to produce polyvinylidene chloride resin, which was a polymer with high barrier properties, especially in the barrier of oxygen and water vapor . In addition, VDC could also be used as a raw material for the production of vinylidene fluoride, which had a very wide range of applications .…”

Section: Introductionmentioning

confidence: 99%

Catalyst Deactivation Process in 1,1,2-TCE Catalytic Dehydrochlorination Reaction

Ge,

Zhao,

Yuan

et al. 2024

Ind. Eng. Chem. Res.

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The heterogeneous catalytic splitting reaction of 1,1,2trichloroethane (1,1,2-TCE) was designed to study the process of catalyst deactivation. The results showed that the conversion of 1,1,2-TCE decreased from 51.34 to 44.01%, while the selectivity of vinylidene chloride decreased from 65.12 to 61.77% (260 °C, 8h), which indicated a decrease in catalyst activity. Solid-phase microextraction gas chromatography−mass spectrometry characterization was performed to confirm species on the surface of the spent catalyst. Density functional theory calculations revealed the essence of 1,1,2-TCE splitting to produce different products, and then a possible reaction network was proposed. Tandem side reactions occurred to generate chloroacetylene, which was an unstable species. Chloroacetylene selfpolymerized to form dichlorobutadiene and further polymerized to form aromatic compounds. The coke deposition precursors agglomerated on the surface of the active component, leading to catalyst deactivation. These conclusions explained the deactivation of the catalyst during 1,1,2-TCE dehydrochlorination, thus providing a theoretical basis for further research on methods to inhibit deactivation. Breaking through the key problem of catalyst deactivation would make it possible to replace the saponification reaction with catalytic dehydrochlorination in industry.

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Effect of swift heavy ion irradiation on thermal, optical and structural properties of poly vinylidene chloride

Cited by 15 publications

References 28 publications

Study of the Relationship between Changes in the Structural, Optical, and Strength Properties of AlN Ceramics Subjected to Irradiation with Heavy Xe23+ Ions

Study of the Relationship between Changes in the Structural, Optical, and Strength Properties of AlN Ceramics Subjected to Irradiation with Heavy Xe23+ Ions

Investigation on Catalytic Cracking Performance of Metal Catalysts for 1,1,2‐TCE

Catalyst Deactivation Process in 1,1,2-TCE Catalytic Dehydrochlorination Reaction

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