Kinetics of radiation-induced degradation of CF2- and CF-groups in poly(vinylidene fluoride): Model refinement

Brief Review of PVDF Properties and Applications Potential

Currently, there is an ever-growing interest in carbon materials with increased deformation-strength, thermophysical parameters. Due to their unique physical and chemical properties, such materials have a wide range of applications in various industries. Many prospects for the use of polymer composite materials based on polyvinylidene fluoride (PVDF) for scientific and technical purposes explain the plethora of studies on their characteristics "structure-property", processing, application and ecology which keep appearing. Building a broader conceptual picture of new generation polymeric materials is feasible with the use of innovative technologies; thus, achieving a high level of multidisciplinarity and integration of polymer science; its fundamental problems are formed, the solution of which determines a significant contribution to the natural-scientific picture of the modern world. This review provides explanation of PVDF advanced properties and potential applications of this polymer material in its various forms. More specifically, this paper will go over PVDF trademarks presently available on the market, provide thorough overview of the current and potential applications. Last but not least, this article will also delve into the processing and chemical properties of PVDF such as radiation carbonization, β-phase formation, etc.

Degradation of PVDF-Coated Fabrics after Engineering Applications: Correlations between Surface Microstructure, Physical Properties, and Mechanical Properties Based on Statistical Analysis

Material degradation has marked impact on the long-term properties and service life of membrane structures. This study is aimed at assessing and understanding the deterioration in visual aspect, surface microstructure, and mechanical properties of a polyvinylidene fluoride (PVDF) polymer after engineering applications. Three groups of PVDF-coated fabrics were removed from different membrane structures in China, which have been used for 15, 16, and 19 years, respectively. Firstly, spectrocolorimetry tests were carried out to determine the evolution of chromaticity and lightness. Other methods such as contact angle and thickness measurements were used to characterize the physical properties. Then, surface morphology was observed by using scanning electron microscope (SEM) technology. Moreover, a series of uniaxial tensile tests and tearing tests were performed to obtain the mechanical indicators including uniaxial tensile strength, strain at break, tearing strength, and uniaxial elastic modulus. In order to further study the degradation mechanism, infrared spectroscopy was used to characterize the molecular structure of aged fabrics. Finally, Principal Component Analysis (PCA) provided a comprehensive description of correlations between surface microstructure, physical properties, and mechanical properties. This paper offers a further understanding of the design, qualification, and durability evaluation of membrane structures.

EUV photofragmentation study of hybrid nonchemically amplified resists containing antimony as an absorption enhancer

A detailed investigation to understand the mechanism of the resist action at a fundamental level is essential for future Extreme Ultraviolet Lithography (EUVL) resists. The photodynamics study of a newly developed hybrid nonchemically amplified 2.15%-MAPDSA-MAPDST resist using synchrotron radiation excitation at 103.5 eV (12 nm) is presented. Antimony was incorporated in the resist as a heavy metal absorption center in the form of antimonate (2.15%). The results showed the fast decomposition rate of the radiation sensitive sulfonium triflate. HR-XPS and sulfur L-NEXAFS spectra of the copolymer films revealed that after irradiation the Ar-S+-(CH3)2 sulfonium group bonded to the phenyl ring resisted the EUV excitation. Those results confirmed the polarity switching mechanism from hydrophilic sulfonium triflates to hydrophobic aromatic sulfides obtained in previous results. The inorganic component SbF6 - included in the resist formulations as an EUV absorption enhancer was particularly illustrative of the photofragmentation process. F 1s and O 1s HR-XPS spectra showed that fluorine remains linked to the antimony, even after 15 min of irradiation. A change of the antimony oxidation state was also observed with an increase in irradiation time. The presence of the heavy metal may control the high energy deposited on the resist which finally led to very well resolved 20 nm isolated line patterns by EUVL. The 10 times improved sensitivity compared with previous poly-MAPDST resists studied in the past showed the potential of this class of hybrid resists for next generation semiconductor industry applications.