Article
Polymer Science
Zakaria Belbakra, Alessandro Napoli, Zoubair Cherkaoui, Xavier Allonas
Summary: A direct analytical method using multi-step pyrolysis-GC/MS was developed to characterize UV-cured networks, with a focus on (meth)acrylate-based systems. The technique revealed a clear reversion process of methacrylates during pyrolysis, while the decomposition of acrylates in high molecular weight degradation products was not easily detected. The potential impact of this method on elucidating the structural and compositional nature of UV-cured polymeric networks was emphasized.
Article
Chemistry, Physical
D. A. Romero-Fierro, L. A. Camacho-Cruz, M. R. Bustamante-Torres, S. P. Hidalgo-Bonilla, E. Bucio
Summary: The study proposed modifying cotton gauzes through grafting pH-sensitive polymers using gamma radiation as a means of achieving drug delivery. The successful modification of the devices was verified with analytical techniques, revealing novel properties such as a critical pH close to 4.7 for application to acidic skin wounds, and the ability to load antimicrobial drugs onto the grafted materials for development of antimicrobial materials.
RADIATION PHYSICS AND CHEMISTRY
(2022)
Article
Chemistry, Physical
Romelly Eugenia Rojas Ramirez, Elisa Souza Orth, Cassiano Pires, Sonia Faria Zawadzki, Rilton Alves de Freitas
Summary: The in situ acrylic acid polymerization reaction at the liposome surface was studied, showing that the adsorption of AA onto the liposome interface is dependent on pH and concentration; the liposome size affects the polymerization kinetics, but has little impact on the formation of nanocapsules.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Food Science & Technology
Noemi Petrovics, Csaba Kirchkeszner, Antonia Patko, Tamas Tabi, Norbert Magyar, Ilona Kovacsne Szekely, Balint Samuel Szabo, Zoltan Nyiri, Zsuzsanna Eke
Summary: The relationship between swelling, migration and polymer crystallinity was investigated in polylactic acid (PLA)-based plastics. Kinetic experiments were conducted at different temperatures using plasticized/non-plasticized and annealed/unannealed PLA specimens. Results showed that the presence of polymer crystals inhibited both swelling and migration. Crystallization induced significant differences in migration at 40 degrees C, which became more pronounced with increasing molecular weight (Mw) of additives. The application of crystallized PLA and high Mw additives is advantageous in reducing migration in the food packaging industry. The solvent-induced crystallization of PLA in 95% ethanol was also confirmed, suggesting restrictions in the use of this alternative food simulant in migration testing of PLA-based plastics.
FOOD PACKAGING AND SHELF LIFE
(2023)
Article
Polymer Science
Jelena D. Jovanovic, Borivoj K. Adnadjevic
Summary: In this study, the kinetics of NIAM release from PAM xerogel/hydrogel under SMHC conditions were investigated, and it was found to follow a first-order chemical reaction kinetic model. The release rate constants ranged from 8.4 10(-3) s(-1) to 15.7 10(-3) s(-1) at different temperatures. The validity of the Arrhenius equation under SMHC conditions was confirmed, and higher kinetic and thermodynamic parameters were attributed to the formation of a specific activated complex.
Article
Chemistry, Physical
Durai Murugan Kandhasamy, Jothivenkatachalam Kandasamy, Sekar Chinnathambi, Magda H. Abdellattif
Summary: The excited-state dynamics of fluorescent probes attached to polymer segments provide insights into the internal dynamics and interior polarity of both synthetic and natural polymers under un-entangled conditions. In this study, the femtosecond dynamics of a well-known molecular probe, proflavine cation, were investigated to uncover the structural dynamics of polymethacrylic acid. The experimental results revealed that the pH of the solution affects the reorientation of water molecules and solvent reorganization processes.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Chemistry, Multidisciplinary
Kai C. Betz, Anna Westhues, Werner Pauer
Summary: The radical polymerization of acrylic acid in isopropanol was investigated in this study, revealing linear correlations between reaction parameters and molecular weight, with reaction rate constants in isopropanol being approximately 10 times slower than in water under similar conditions.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Han Yu, Junjie Liu, Lin Zhao, Yonglin Liu, Lulu Gu, Lianxiang Feng, Yonggen Weng, Qingxu Duan, Baorong Duan, Jiale Qu
Summary: The suspension polymerization process was used to create acrylate resin microspheres for mesh coating technology. The synthesized microspheres had mesh numbers of 140-200 µm and particle sizes of 100 µm. The optimal reaction conditions for synthesis were determined to be a dispersant dosage of 30 g of calcium carbonate, a monomer ratio of 4:1, a reaction time of 1 h, an initiator dosage of 1.2 g of BPO, and a reaction temperature of approximately 75-80 °C, resulting in microspheres with a regular spherical shape and smooth surface.
FRONTIERS IN CHEMISTRY
(2023)
Article
Spectroscopy
Nurlely, Musa Ahmad, Lee Yook Heng, Ling Ling Tan
Summary: The optical biosensor developed for formaldehyde detection has shown high sensitivity, good linearity, and high reproducibility. It has a rapid response time and can detect formaldehyde across a wide concentration range, making it a reliable method for quantitative determination of formaldehyde levels in various samples.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Energy & Fuels
Hae Ri Lee, Youn-Ki Lee, Gwan Gyu Park, Sungho Lee, Han-Ik Joh
Summary: Molybdenum sulfide-based materials have been studied as a potential alternative to low-capacity graphite anodes due to their remarkable capacity through intercalation and conversion reactions. However, their inert basal plane and unstable sulfur configuration lead to low performance. Using sulfur-enriched crystalline Mo3S13 clusters as an anode material can increase active sites and energy densities.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Polymer Science
Syed Asim Hussain Shah, Muggundha Raoov Ramachandran, Sity Aishah Mansur, Noorashikin Md Saleh, Saliza Asman
Summary: The synthesis and characterization of a deep eutectic solvent molecularly imprinted polymer (DES-MIP) has shown that it exhibits a higher selectivity and binding capacity for bisphenol A (BPA) compared to structurally similar compounds. The DES-MIP has been found to have optimal binding capacity at pH 7 and its adsorption follows pseudo-second-order kinetic and Langmuir isotherm models. Thermodynamic analysis indicates that the adsorption of BPA on DES-MIP is exothermic and spontaneous. The DES-MIP is a promising adsorbent with high adsorption capability, remarkable selectivity, and good reusability.
Article
Multidisciplinary Sciences
Janina Kabatc-Borcz, Przemyslaw Czelen, Agnieszka Skotnicka
Summary: One of the most basic properties of chemical compounds is their structural symmetry or asymmetry. This property is related to the physical, chemical, biological, and technological properties of organic compounds, which depend on their chemical structure. This paper focuses on the synthesis and spectroscopic properties of photoinitiators derived from acrylate and methacrylate derivatives of 2-(benzothiazolylthio)ethyl, which have potential application in medicine. Infrared spectroscopy (IR) and nuclear magnetic resonance (NMR) spectroscopy were used to characterize the compounds, and their spectroscopic properties were determined using UV-Vis spectra. The calculated DFT energies and Frontier Molecular Orbitals calculations were consistent with experimental observations, showing that the introduction of the ethoxy substituent increases reactivity and results in a slight bathochromic shift of the absorption spectra maxima (about 19 nm).
Article
Chemistry, Applied
Zhuxin Li, Xue Lv, Zhaoxian Che, Hanlu Liao, Jie Zheng
Summary: This study investigated the crosslinking process of waterborne acrylic resin with total-methyl etherified amino resin to form a film and the pyrolysis kinetics of the resulting product. By analyzing the kinetic parameters and mechanism function of the thermal degradation, it was found that the crosslinked product exhibited improved flexibility, adhesion, and thermal stability.
PROGRESS IN ORGANIC COATINGS
(2022)
Article
Engineering, Chemical
Maryam Agboluaje, Gagandeep Kaur, Eva Dusicka, Anna Urbanova, Mohammad Pishnamazi, Branislav Horvath, Miroslav Janata, Vladimir Raus, Igor Lacik, Robin A. Hutchinson
Summary: This study synthesized multi-functional polymers for personal care products through radical polymerization of acrylic acid with non-functional monomers in alcohol/water solutions. The kinetic coefficients required for the terpolymerization system were estimated from fitting experiments, and in-situ nuclear magnetic resonance spectroscopy was used to track monomer conversions and composition changes. The molar mass distributions of the polymer products were characterized by size-exclusion chromatography.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Engineering, Chemical
Maryam Agboluaje, Robin A. Hutchinson
Summary: The influence of alcohol and alcohol/water solutions on the radical copolymerization kinetics of HEMA with MEA was studied. MEA incorporation into the copolymer was increased in alcohol and alcohol/water solutions. Adding water as cosolvent significantly increased the propagation rate coefficient for both monomers.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2022)
Article
Chemistry, Organic
Jonas Everaert, Maarten Debruyne, Flore Vanden Bussche, Kristof Van Hecke, Thomas S. A. Heugebaert, Pascal Van der Voort, Veronique Van Speybroeck, Christian Stevens
Summary: This paper presents the synthesis of new nitrile-functionalized N-heterocyclic ligands, which vary in the extent of the aromatic system and denticity. These ligands can be used for rational design of enhanced support materials in catalysis.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Physical
Sander Vandenhaute, Maarten Cools-Ceuppens, Simon DeKeyser, Toon Verstraelen, Veronique Van Speybroeck
Summary: In this study, an incremental learning scheme is proposed to construct accurate and data-efficient machine learning potentials for metal-organic framework materials. The scheme combines equivariant neural network potentials with parallelized enhanced sampling and on-the-fly training to explore and learn the phase space iteratively. With only a few hundred single-point density functional theory evaluations per material, accurate and transferable potentials are obtained, even for flexible frameworks with multiple structurally different phases. This incremental learning scheme is universally applicable and may pave the way to model framework materials in larger spatiotemporal windows with higher accuracy.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Sander Borgmans, Sven M. J. Rogge, Juul S. De Vos, Pascal van der Voort, Veronique Van Speybroeck
Summary: Soft porous crystals with stimuli responsiveness are widely studied for various applications. However, the structural flexibility in 3D covalent organic frameworks (COFs) is not well understood. This study investigates the factors affecting the phase transformations of diamondoid COFs, including structural decoration, interpenetration, temperature, and guest adsorption. It provides a comprehensive understanding of the design principles for flexible diamondoid COFs.
COMMUNICATIONS CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jiamin Sun, Himanshu Sekhar Jena, Chidharth Krishnaraj, Kuber Singh Rawat, Sara Abednatanzi, Jeet Chakraborty, Andreas Laemont, Wanlu Liu, Hui Chen, Ying-Ya Liu, Karen Leus, Henk Vrielinck, Veronique Van Speybroeck, Pascal Van Der Voort
Summary: Four highly porous covalent organic frameworks (COFs) containing pyrene units were prepared and explored for photocatalytic H2O2 production. Experimental studies and density functional theory calculations showed that the pyrene unit has higher activity for H2O2 production compared to bipyridine and (diarylamino)benzene units. The distribution of pyrene units over a large surface area of COFs was found to be crucial for catalytic performance.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Editorial Material
Nanoscience & Nanotechnology
Choongseok Chang, Volker L. Deringer, Kalpana S. Katti, Veronique Van Speybroeck, Christopher M. Wolverton
Summary: Exascale computers, capable of performing 10(18) floating point operations per second, have started to become operational in 2022. The United States has launched Frontier as the first public exascale supercomputer, and Aurora is set to open soon. In China, OceanLight and Tianhe-3 are already operational, while Europe is getting ready to launch JUPITER in 2023. Supercomputers present unprecedented opportunities for modeling complex materials.
NATURE REVIEWS MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Alexander E. J. Hoffman, Joao Marreiros, Sven M. J. Rogge, Rob Ameloot, Veronique Van Speybroeck
Summary: Mixed-linker zeolitic imidazolate frameworks (ZIFs) are candidate materials for gas separation. The pore size of ZIFs can be regulated by changing the linker content, which affects diffusion and adsorption. The linker distribution in mixed-linker ZIF-8/ZIF-90 is characterized using computational Raman spectroscopy, revealing the impact of hydrogen bonding behavior on the distribution.
ACS APPLIED NANO MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Maarten Debruyne, Sander Borgmans, Sambhu Radhakrishnan, Eric Breynaert, Henk Vrielinck, Karen Leus, Andreas Laemont, Juul De Vos, Kuber Singh Rawat, Siebe Vanlommel, Hannes Rijckaert, Hadi Salemi, Jonas Everaert, Flore Vanden Bussche, Dirk Poelman, Rino Morent, Nathalie De Geyter, Pascal Van Der Voort, Veronique Van Speybroeck, Christian V. Stevens
Summary: Covalent organic frameworks (COFs) are a new type of photoactive organic semiconductors with ordered structures and high surface areas. The band gaps of COFs can be tuned by the choice of building blocks and linkages, making them tailor-made for specific (photocatalytic) applications. However, there are still many unexplored building blocks for COFs as photocatalytic moieties, and the scope of photocatalyzed reactions by COFs is limited.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Chemical
Idil I. Demiralp, Ipek Azizoglu, A. Barkin Cimen, Mert Haktanir, Seda Karahan, Zeynep Pinar Haslak, Viktorya Aviyente
Summary: Highly acidic crude oils are considered as good alternatives to typical crude oils for transportation fuels, but their corrosion poses a major concern. This study uses quantum mechanical tools to understand the unimolecular decomposition of carboxylic acids and naphthenic acids (NAs). The results reveal the effects of temperature and other factors on the decomposition process, which can help optimize the processes and provide reaction rates for kinetic models.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Sven M. J. Rogge, Sander Borgmans, Veronique Van Speybroeck
Summary: This article introduces strain engineering as a general approach to rationalize and design materials by modifying their atomic level structure. The potential of strain engineering is demonstrated through two examples, showing how it can be used to design state-of-the-art materials for challenging applications.
Article
Chemistry, Physical
Pieter Cnudde, Michel Waroquier, Veronique Van Speybroeck
Summary: The influence of pore topology and acid strength on the adsorption of (iso)butene in Bronsted acid zeolites has been studied using calculations and simulations. The adsorbed intermediates - physisorbed alkene, chemisorbed carbenium ion, and alkoxide - were evaluated for different zeolite topologies and acid site strengths. The stabilization of the carbenium ion depends on zeolite confinement and acid site strength, while alkoxides are not found at high temperature. The adsorption energies and protonation barriers can be predicted using universal descriptors such as dispersion component and ammonia adsorption energy.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Alexander E. J. Hoffman, Irena Senkovska, Leila Abylgazina, Volodymyr Bon, Veronika Grzimek, Anna Maria Dominic, Margarita Russina, Marvin A. Kraft, Inez Weidinger, Wolfgang G. Zeier, Veronique Van Speybroeck, Stefan Kaskel
Summary: This study utilizes spectroscopic techniques and density functional theory calculations to investigate the vibrational properties of DUT-8(M) materials with different metal nodes (M = Ni, Co, Zn, Cu). Experimental results show that the closed pore phase of the Ni-based compound is stiffer than those containing Co and Zn, while the open pore phase is softer. Theoretical calculations suggest that changing the metal atom mainly affects the phonon modes inducing changes in the paddle wheel unit. These findings provide valuable insights into the flexibility and phase transition mechanism of switchable MOFs.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Nanoscience & Nanotechnology
Alexander E. J. Hoffman, Rafikul Ali Saha, Sander Borgmans, Pascal Puech, Tom Braeckevelt, Maarten B. J. Roeffaers, Julian A. A. Steele, Johan Hofkens, Veronique Van Speybroeck
Summary: Metal-halide perovskites (MHPs) have excellent properties for optoelectronic devices, but their long-term stability and phase transitions need to be understood. This study used GIWAXS, Raman spectroscopy, and theoretical calculations to investigate the structural phase transitions and phonon modes in CsPbBr3. The results provided direct evidence for the existence of these phase transitions and identified the Raman active phonon modes. This work enhances our understanding of the structure and lattice dynamics of CsPbBr3 and similar MHPs.
Article
Chemistry, Organic
Semiha Kevser Bali, Zeynep Pinar Haslak, Gulsah Cifci, Viktorya Aviyente
Summary: The human topoisomerase IB enzyme relaxes supercoils on double-stranded DNA by forming a covalent DNA/hTopoIB complex. Inhibition of hTopoIB results in cell death, making it a potential target for cancer treatment. Different inhibitors, such as CPT and IQN, have shown different preferences for DNA bases when bound to the DNA/hTopoIB complex. This study investigates the affinities of CPT and an IQN derivative to different DNA base pairs, providing insights for designing gene-specific and more potent compounds to combat cancer through hTopoIB poisoning.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jonas Everaert, Karen Leus, Hannes Rijckaert, Maarten Debruyne, Kristof Van Hecke, Rino Morent, Nathalie De Geyter, Veronique Van Speybroeck, Pascal Van Der Voort, Christian V. Stevens
Summary: Covalent triazine frameworks (CTFs) based on polydentate ligands are promising catalyst supports that combine the reactivity of homogeneous catalysts with the robustness and recyclability of heterogeneous ones. In this study, a rhodium (III) complex was immobilized on a bipyridine-based CTF for the transfer hydrogenation of N-heteroarenes in water using sodium formate as the hydrogen source. The immobilized catalyst showed excellent activity for various quinoxalines and other N-heteroarenes, and maintained high activity during recycling, making it suitable for continuous flow synthesis.
Article
Chemistry, Physical
Juul S. De Vos, Sander Borgmans, Pascal Van Der Voort, Sven M. J. Rogge, Veronique Van Speybroeck
Summary: This article introduces a database called ReDD-COFFEE, which contains 268,687 covalent organic frameworks (COFs) with accompanying ab initio derived force fields that outperform generic ones. The database provides a large number of computer-ready structures with high diversity in terms of geometric properties, linker cores, and linkage types. Additionally, the textural properties of the database are analyzed and the most promising COFs for vehicular methane storage are identified. By making the database freely accessible, it is hoped that it can inspire others to further explore the potential of these intriguing functional materials.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
