In this paper, the surface properties, e.g., the total surface free energy and the related Lifshitz-van der Waals and Lewis acid-base components, of polyacrylonitrile (PAN) precipitation polymerized in supercritical CO(2) have been characterized. Moreover, the influence of molecular weight varying has been also investigated. Results show that the surface properties of PAN resulting from supercritical CO(2) are different from those obtained by the conventional method. Of these data, one important finding is that the supercritical CO(2) PAN seems to decrease the surface free energy with the increased molecular weight. Based on previous recorded NMR spectra of this PAN and especially compared to commercial PAN, such phenomena are discussed and ascribed to an increase of the H-bonds and a reduction of the isotacticity in the supercritical CO(2) condition for PAN.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0021-9797(03)00651-9 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Sulfate Promotes Compact CaCO Formation and Protects Portland Cement from Supercritical CO Attack.
Environ Sci Technol
January 2025
Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States.
Supercritical (sc) CO in geologic carbon sequestration (GCS) can chemically and mechanically deteriorate wellbore cement, raising concerns for long-term operations. In contrast to the conventional view of "sulfate attack" on cement, we found that adding 0.15 M sulfate to the acidic brine can significantly reduce the impact of scCO attack on Portland cement, resulting in stronger cement than that found in a sulfate-free system.
View Article and Find Full Text PDFEffect of Process Parameters on Nano-Microparticle Formation During Supercritical Antisolvent Process Using Mixed Solvent: Application for Enhanced Dissolution and Oral Bioavailability of Telmisartan Through Particle-Size Control Based on Experimental Design.
Pharmaceutics
November 2024
College of Pharmacy and Research Institute for Drug Development, Pusan National University, 63 Busandaehak-ro, Geumjeong-gu, Busan 46241, Republic of Korea.
This study investigates the impact of supercritical antisolvent (SAS) process parameters on the particle formation of telmisartan, a poorly water-soluble drug. A fractional factorial design was employed to examine the influence of the SAS process parameters, including solvent ratio, drug solution concentration, temperature, pressure, injection rate of drug solution, and CO₂ flow rate, on particle formation. Solid-state characterizations of the SAS process particles using XRD and FT-IR confirmed their amorphous nature.
View Article and Find Full Text PDFUnlocking the Unique Potential of : Exploring the Efficacy of Supercritical CO Extraction, with and Without Pre-Treatments.
Plants (Basel)
December 2024
Faculty of Technology Novi Sad, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia.
Since ancient times, many plant species within the genus have been used due to their numerous health benefits, such as antimicrobial, anti-inflammatory, antiseptic, or diuretic activity. While many of the species within this genus were well known and described, All. or Pannonian thyme remains relatively unexplored despite its unique chemical composition and activity.
View Article and Find Full Text PDFNatural Deep Eutectic Solvents Combined with Supercritical Carbon Dioxide for the Extraction of Curcuminoids from Turmeric.
Pharmaceuticals (Basel)
November 2024
Department of Pharmacognosy and Biomaterials, Poznan University of Medical Sciences, Rokietnicka 3, 60-806 Poznan, Poland.
Background: Curcuminoids, the bioactive compounds found in turmeric, exhibit potent antioxidant, anti-inflammatory, and neuroprotective properties. This study aims to enhance the extraction of curcuminoids from turmeric using environmentally friendly solvents supercritical CO (scCO) combined with natural deep eutectic solvents (NADESs) in one process, and to evaluate the resulting biological activity.
Methods: A Box-Behnken statistical design was applied to optimize scCO extraction conditions-pressure, CO volume, and temperature-to maximize curcuminoid yield.
Antimicrobial and Antibiofilm Activity of Extracts Obtained by Supercritical Fluid Extraction Under Various Extraction Conditions.
Molecules
December 2024
Department of Food Safety and Chemical Analysis, Waclaw Dąbrowski Institute of Agricultural and Food Biotechnology-State Research Institute, Rakowiecka 36, 02-532 Warsaw, Poland.
Sustainable management of agri-food product safety presents a major challenge requiring extensive action to ensure food safety and consumer health. The pursuit of environmentally friendly solutions that will constitute an alternative to the chemical compounds commonly used in agriculture and the food industries is one of the most important problems. One solution is plant extracts containing various biologically active compounds and exhibiting antimicrobial activity.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!