In this study we have investigated the features of the glass transition relaxation of indomethacin using Differential Scanning Calorimetry (DSC). The purpose of this work is to provide an estimation of the activation energy at the glass transition temperature, as well as of the fragility index, of amorphous indomethacin from DSC data. To do so, the glass transition temperature region of amorphous indomethacin was characterized in both cooling and heating regimes. The activation energy for structural relaxation (directly related to glass fragility) was estimated from the heating and cooling rate dependence of the location of the DSC profile of the glass transition. The obtained results were similar in the heating and in the cooling modes. The results on the fragility index of indomethacin obtained in the present study, m = 60 in the cooling mode and m = 56 in the heating mode, are compared with other values previously published in the literature.
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http://dx.doi.org/10.1002/jps.20061 | DOI Listing |
Int J Biol Macromol
January 2025
Department of Food Engineering and Technology, Sant Longowal Institute of Engineering and Technology (SLIET), Longowal, 148106 Sangrur, Punjab, India. Electronic address:
In the present investigation, the formulation and thorough assessment of biodegradable composite films were conducted, utilizing pectin extracted from banana peel in conjunction with synthesized silver zeolite nanoparticles. The evaluation of physical properties, microstructural investigation, mechanical characteristics, and barrier properties was done providing valuable insights into various attributes of the film. The amalgamation of silver zeolite nanoparticles with the extracted pectin from banana peel results in biodegradable composite films exhibiting distinct physical, mechanical, barrier, and thermal properties.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Physical vapor deposition is widely used in the fabrication of organic light-emitting diodes and has the potential to adjust the density and orientation through substrate temperature control, which may lead to enhanced electrical performance. However, it is unclear whether this enhanced property is because of the horizontal molecular orientation or the increased density. The effects of the density and orientation on the electrical properties of a potential electron transport material, (3-dibenzo[c,h]acridin-7-yl)phenyl)diphenylphosphine oxide (TPPO-dibenzacridine), were investigated.
View Article and Find Full Text PDFPharmaceutics
January 2025
Department of Chemical and Pharmaceutical Sciences, University of Trieste, Piazzale Europa 1, 34127 Trieste, Italy.
This study investigates the preparation of coamorphous systems composed entirely of active pharmaceutical ingredients (APIs), namely praziquantel, niclosamide, and mebendazole. The objective was to formulate and characterize binary and ternary coamorphous systems to evaluate their structural, thermal, and stability properties. Ten different mixtures (binary and ternary) were designed through a mixture design approach and prepared using a sustainable, one-step neat grinding process in a lab-scale vibrational mill.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Rheology Department, Polymat Institute, University of the Basque Country, 20018 Donostia-San Sebastian, Euskadi, Spain.
This paper addresses the author's current understanding of the physics of interactions in polymers under a voltage field excitation. The effect of a voltage field coupled with temperature to induce space charges and dipolar activity in dielectric materials can be measured by very sensitive electrometers. The resulting characterization methods, thermally stimulated depolarization (TSD) and thermal-windowing deconvolution (TWD), provide a powerful way to study local and cooperative relaxations in the amorphous state of matter that are, arguably, essential to understanding the glass transition, molecular motions in the rubbery and molten states and even the processes leading to crystallization.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand.
Poly(lactic acid) (PLA) exhibits excellent shape memory properties but suffers from brittleness and a high glass transition temperature (T), limiting its utility in flexible and durable applications. This study explored the modification of PLA properties through the incorporation of poly(ethylene glycol) (PEG), varying in both content (5-20 wt%) and molecular weight (4000-12,000 g/mol), to enhance its suitability for specific applications, such as medical splints. The PLA/PEG blend, containing 15 wt% PEG and with a molecular weight of 12,000 g/mol, exhibited superior shape fixity (99.
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