In this contribution the sorption of water vapor in Poly(L-lactic acid) (PLLA) was studied by time-resolved FTIR spectroscopy. The collected FTIR data were analyzed by complementary approaches such as difference spectroscopy, two-dimensional correlation spectroscopy (2D-COS), and least-squares curve-fitting analysis which provided information about the overall diffusivity, the nature of the molecular interactions among the polymer and the penetrant and the dynamics of the various molecular species. The diffusion coefficient were evaluated as a function of vapor activity and were found in good agreement with previously reported values. The system showed a Fickian behavior with diffusivity increasing with penetrant concentration. Two distinct water species (first-shell and second-shell layers) were detected and quantified by coupling FTIR and gravimetric measurements.
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http://dx.doi.org/10.3389/fchem.2019.00275 | DOI Listing |
Foods
December 2024
Instituto de Ciencia y Tecnología de los Alimentos Córdoba (ICYTAC-CONICET), Universidad Nacional de Córdoba, Av. Filloy S/N, Ciudad Universitaria, Córdoba CP 5000, Argentina.
The morphology of wheat starch granules with different damaged starch (DS) content was analyzed using a particle size analyzer and scanning electron microscopy (SEM); the granular structure was studied using FT-IR spectroscopy and X-ray diffraction (XRD); and the granule-water interaction was evaluated by thermogravimetric analysis (TGA) and dynamic vapor sorption (DVS). The increase in the level of DS shifted the population of B-type granules towards larger particle diameters and shifted the population of A-type granules towards smaller particle diameters. The appearance of the surface of the starch-damaged granules was rough and flaky (SEM images).
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Department of Chemistry and Chemical Technology, M.Kh. Dulaty Taraz University, Taraz 080000, Kazakhstan.
This review presents a comprehensive review of cellulose-chitosan-based biocomposites that have high potential as sustainable alternatives to synthetic polymers. These biocomposites, due to biocompatibility, biodegradability, and antimicrobial properties, attract attention for wide application in various industries. This review includes modern methods for producing cellulose-chitosan composites aimed at improving their mechanical and chemical properties, such as strength, flexibility, and water resistance.
View Article and Find Full Text PDFJ Environ Radioact
January 2025
Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/STAAR/LRTA, PSE-ENV/SPDR/LT2S, Saint-Paul-lez-Durance, F-13115, France. Electronic address:
The transfer of radionuclides discharged into rivers by nuclear facilities are conditioned by their solid/liquid fractionation, commonly represented by an equilibrium approach using the distribution coefficient K. This coefficient, largely used in modeling, assumes an instantaneous and completely reversible reaction. However, such assumptions are rarely verified.
View Article and Find Full Text PDFJ Contemp Dent Pract
September 2024
Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil; Department of Dentistry, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands, ORCID: https://orcid.org/0000-0002-5166-8233.
Aim: This study aimed to assess if the addition of origanum oil to denture materials could decrease microorganisms counts and biofilm formation without changing their mechanical/surface properties.
Materials And Methods: A total of 66 resilient denture liner discs (SoftConfort, Dencril Comércio de Plásticos Ltda, SP, Brazil) were prepared with fixed dimensions of 10 × 3 mm for biofilm assay ( = 36) and 12 × 2 mm for sorption-solubility tests ( = 30) containing three oil concentrations - 0, 2.5 and 5%, thereby = 12 per each group samples for biofilm assay and = 10 per each group for sorption-solubility test respectively.
Water Res
December 2024
Department of Technical Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig 04318, Germany. Electronic address:
The complex sorption mechanisms of carbon adsorbents for the diverse group of persistent, mobile, and potentially toxic contaminants (PMs or PMTs) present significant challenges in understanding and predicting adsorption behavior. While the development of quantitative predictive tools for adsorbent design often relies on extensive training data, there is a notable lack of experimental sorption data for PMs accompanied by detailed sorbent characterization. Rather than focusing on predictive tool development, this study aims to elucidate the underlying mechanisms of sorption by applying data analysis methods to a high-quality dataset.
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