Introduction of a Methodology to Enhance the Stabilization Process of PAN Fibers by Modeling and Advanced Characterization.

A methodology for designing the oxidative stabilization process of polyacrylonitrile (PAN) fibers is examined. In its core, this methodology is based on a model that describes the characteristic fiber length variation during thermal processing, through the de-convolution of three main contributors (i.e., entropic and chemical shrinkage and creep elongation). The model demonstrated an additional advantage of offering further insight into the physical and chemical phenomena taking place during the treatment. Validation of PAN-model prediction performance for different processing parameters was achieved as demonstrated by Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). Τensile testing revealed the effect of processing parameters on fiber quality, while model prediction demonstrated that ladder polymer formation is accelerated at temperatures over 200 °C. Additionally, according the DSC and FTIR measurements predictions from the application of the model during stabilization seem to be more precise at high-temperature stabilization stages. It was shown that mechanical properties could be enhanced preferably by including a treatment step below 200 °C, before the initiation of cyclization reactions. Further confirmation was provided via Raman spectroscopy, which demonstrated that graphitic like planes are formed upon stabilization above 200 °C, and thus multistage stabilization is required to optimize synthesis of carbon fibers. Optical Microscopy proved that isothermal stabilization treatment did not severely alter the cross section geometry of PAN fiber monofilaments.

Design, Rationale, Methodology, and Aims of a Greek Prospective Idiopathic Pulmonary Fibrosis Registry: Investigating Idiopathic Pulmonary Fibrosis in Greece (INDULGE IPF).

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic, fibrosing interstitial pneumonia of unknown origin. Despite the fact that the guidelines on the diagnosis and management of the disease were updated in 2015, incorporating novel agents recently introduced in the therapeutic approach of IPF, there is a lack of data on the epidemiology, disease status, and treatment in clinical practice. Contemporary data provided by national registries in IPF provide valuable information to guide clinical management of the disease in the real-world setting, adjusted to the local needs. OBJECTIVE: Investigating Idiopathic Pulmonary Fibrosis in Greece (INDULGE IPF) is a Greek observational registry aiming at gaining further knowledge on the characteristics, management, progression, and outcomes of patients with IPF treated under real-world, clinical practice conditions in Greece. METHODS: Approximately 300 patients will be enrolled consecutively in seven reference centers, constituting the largest IPF registry ever established in Greece. CONCLUSION: This registry is expected to provide data on the characteristics of IPF patients in Greece and the entire clinical management during the course of the disease.