Article
Engineering, Chemical
Sebastian Simu, Adriana Ledeti, Elena-Alina Moaca, Cornelia Pacurariu, Cristina Dehelean, Dan Navolan, Ionut Ledeti
Summary: This study analyzes the thermal stability and decomposition kinetics of ethinylestradiol (EE), a widely used synthetic derivative of estradiol. The results show that the main decomposition process of EE in the temperature range of 175-375 degrees Celsius is a single-step process, unaffected by the heating rate of the sample.
Article
Thermodynamics
Ayokunle O. Balogun, Adekunle A. Adeleke, Peter P. Ikubanni, Samuel O. Adegoke, Abdulbaset M. Alayat, Armando G. McDonald
Summary: The study investigated the thermal degradation of Digitaria sanguinalis in nitrogen (pyrolysis) and air (combustion) atmospheres through thermogravimetric analysis. The grass showed higher reaction rate in the oxidative process of combustion, with different activation energy profiles in nitrogen and air.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Polymer Science
Hamayoun Mahmood, Ahmad Shakeel, Ammar Abdullah, Muhammad Ilyas Khan, Muhammad Moniruzzaman
Summary: Thermal kinetic modeling is crucial for sustainable processes involving lignocellulosic fuels, with thermal decomposition of three materials analyzed using both model-fitting and isoconversional methods. The activation energy order based on model-free analysis is rice husk > bagasse > wheat straw, recommending isoconversional approach as more realistic and precise for modeling non-isothermal kinetics of lignocellulosic residues.
Article
Polymer Science
Adrian Olejnik, Paulina Kosmela, Lukasz Piszczyk
Summary: Thorough thermogravimetric analysis was conducted on bio-based polyurethane-polyisocyanurate (PUR-PIR) foams in both nitrogen and oxygen atmosphere. It was found that foams using biopolyol exhibit enhanced stability in both oxidative atmosphere and nitrogen compared to purely petrochemical foams, with relationships between thermal stability and foam structure established. Enhanced stability in oxygen can be attributed to higher cross-linking density and possibly the presence of more aromatic compounds in the biopolyol structure.
JOURNAL OF POLYMER SCIENCE
(2021)
Article
Astronomy & Astrophysics
Brittany M. DePasquale, David M. Jenkins
Summary: The presence of iron-rich smectite on Mars suggests the former presence of water in the nearsurface environment. Experimental synthesis and thermal stability studies indicate that Fe-smectite can be formed under various compositions and conditions, potentially storing considerable amounts of water. The upper-thermal stability of Fe-smectite also suggests possible formation in the presence of a primordial dense vapor phase in the earliest history of Mars.
Article
Engineering, Chemical
Amalia Ridichie, Adriana Ledeti, Francisc Peter, Ionut Ledeti, Cornelia Muntean, Matilda Radulescu
Summary: This study focuses on the heterogeneous degradation kinetics of the emergency contraceptive agent levonorgestrel (LNG) and compares the degradation processes with a model system containing excipients. The study finds that the excipients have a stabilizing effect on the decomposition of the API in tablet.
Article
Engineering, Environmental
Kesiany M. de Souza, Marcelo J. S. de Lemos, Roberta dos R. Ribeiro, Ana Maria G. Marin
Summary: The transition to a carbon-free economy has led to the development of innovative technologies for permanent P&A of mature oil wells, such as the use of thermites in Thermal P&A technology. This study presents a comprehensive kinetic analysis of the Fe2O3-2Al thermite reaction using DSC data. Multiple kinetic methods were employed to calculate the activation energies for each reaction stage, revealing significant variations with the extent of conversion. Different models were used to describe the reaction stages, with the first stage following a contracting sphere mechanism and the second stage following a random nucleation mechanism. The modeled data showed good agreement with the experimental data for the first stage, but larger deviations were observed for the second stage.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Materials Science, Multidisciplinary
Ding Shen, Lingxiao Ji, Meina Zhao, Xuanyi Zhu, Yingkai Xia, Zongsong Yang, Wei Dong, Shaobin Yang
Summary: Using low-layer protonated montmorillonite and carbon nanotube composites as sulfur carriers can improve the electrochemical performance of lithium-sulfur batteries, showing excellent cycle ability and high rate cycle stability.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Physical
Karol Kulacz, Kazimierz Orzechowski, Balazs Zsirka, Janos Kristof
Summary: This study examines the interactions between unmodified nontronite and nontronite intercalated with formamide. The results show that the low-frequency permittivity of unmodified nontronite is significantly higher than that of the material intercalated with formamide. This may be due to the movement of ions in unmodified nontronite. Intercalation with formamide does not restore the mobility of ions, resulting in a relatively low low-frequency electric permittivity.
APPLIED CLAY SCIENCE
(2022)
Article
Geochemistry & Geophysics
Igor Danilin, Inna Tolpeshta, Yulia Izosimova, Lev Pozdnyakov, Andrey Stepanov, Olga Salimgareeva
Summary: This article studies the sorption regularities of humic acid on different sorbents and evaluates their thermal stability and resistance to microbial degradation. The experiment shows that kaolinite sorbs more humic acids compared to bentonite, and the sorption mainly occurs through hydrophobic components. The sorption of humic acid results in changes in its chemical composition and selective adsorption of nitrogen-containing compounds. The thermal stability of the sorbed humic acid increases with each subsequent sorption cycle.
Article
Thermodynamics
Malgorzata Maciejewska, Magdalena Rogulska
Summary: Porous microspheres modified with 1-(2-hydroxyethyl)-2-pyrrolidone (HP) from 2,3-epoxypropyl methacrylate (GMA) and 1,4-di(methacryloyloxymethyl) naphthalene (DMN) did not show significant changes in internal structure, but exhibited noticeable differences in thermal properties, with improved thermal stability in helium atmosphere when reacted with HP.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Chemistry, Physical
Sen Yang, Xiantang Liu, Gang Yang
Summary: This study uses molecular dynamics simulations to investigate cation exchange mechanisms at clay interfaces, revealing different selectivities for various binary ion systems and highlighting the strong coupling between thermodynamics, kinetics, and confinement effects. The results provide new insights into cation exchange processes at clay interfaces and offer explanations for experimental observations at the molecular level.
APPLIED CLAY SCIENCE
(2021)
Article
Thermodynamics
Vianney Andrew Yiga, Michael Lubwama, Peter Wilberforce Olupot
Summary: Agricultural fiber-reinforced PLA composites with clay as filler show promising potential for improving thermal stability and mechanical properties. The alkali modification of clay enhances its microstructure and increases its suitability as a filler in fiber-reinforced PLA composites. The findings suggest that modified kaolin exhibits improved physical, chemical, and thermal properties, making it a suitable filler material.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Engineering, Chemical
Zhengxiang Zhang, Haibin Zhou, Wentao Li, Chao Tang
Summary: This study investigated the effects of different silane coupling agents on modified cellulose, showing that using KH550 and KH792 modified nano-SiO2 significantly improves the mechanical properties and thermal stability of cellulose, thereby increasing the transformer's lifespan.
Article
Engineering, Environmental
Ye-Cheng Liu, Jun-Cheng Jiang, An-Chi Huang, Yan Tang, Ya-Ping Yang, Hai-Lin Zhou, Juan Zhai, Zhi-Xiang Xing, Chung-Fu Huang, Chi-Min Shu
Summary: This study examines the thermal stabilities of phenolic by-products produced during nitrobenzene formation and establishes advanced thermodynamic models for calculation and fitting, providing reliable data support for exploring the intrinsic stability of nitrification by-products.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2022)
Article
Chemistry, Physical
Ivana Mrsic, Tim Baeuerle, Steffen Ulitzsch, Guenter Lorenz, Karsten Rebner, Andreas Kandelbauer, Thomas Chasse
Summary: A systematic study was conducted on the oxygen plasma surface modifications of polyurethane and cross-linked ethylene-propylene rubber, with oxygen pressure identified as the most impactful factor leading to increased surface energy and polarity at low pressures.
APPLIED SURFACE SCIENCE
(2021)
Article
Polymer Science
Regina Seidl, Stephanie Weiss, Rudolf W. Kessler, Waltraud Kessler, Edith M. Zikulnig-Rusch, Andreas Kandelbauer
Summary: The article demonstrates how accurate predictions of MF residual curing capacity can be derived from inline Fourier Transform infrared (FTIR) spectra recorded during resin synthesis using partial least squares regression. Strong correlations were found between the infrared spectra at the end of MF resin synthesis and the residual curing capacity, as well as in the early stages of resin synthesis, allowing for corrective measures to be taken to avoid discarding faulty batches.
Article
Engineering, Chemical
Stephanie Weiss, Regina Seidl, Waltraud Kessler, Rudolf W. Kessler, Edith M. Zikulnig-Rusch, Andreas Kandelbauer
Summary: The curing of melamine resin at different temperatures results in films with different chemical structures. The cure temperature is the main determining factor for resin functionality. By selecting appropriate curing times and temperature profiles, specific resin networks can be obtained from the same melamine resin.
INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES
(2021)
Article
Chemistry, Multidisciplinary
Akanksha Dohare, Swathi Sudhakar, Bjoern Brodbeck, Ashutosh Mukherjee, Marc Brecht, Andreas Kandelbauer, Erik Schaeffer, Hermann A. Mayer
Summary: The study demonstrates that anisotropic and amphiphilic dumbbell core-shell silica microparticles with chemically selective environments can effectively entrap and release two drugs simultaneously with high efficiency. The drugs accumulate in different compartments of the particles, leading to different cancer cell inhibitory activities.
Article
Chemistry, Analytical
Patrick Wahrendorff, Mona Stefanakis, Julia C. Steinbach, Dominik Allnoch, Ralf Zuber, Ralf Kapfhammer, Marc Brecht, Andreas Kandelbauer, Karsten Rebner
Summary: In this study, a simple spectroscopy-based set-up was introduced for the simultaneous monitoring of three quality parameters of metalworking fluids (MWFs) and a mathematical model was established to relate them to the most influential process factors during use. The research found that pH and MWF concentration had a strong synergistic effect on the aging process of MWF, while nitrite concentration had no significant impact.
Article
Biochemistry & Molecular Biology
Julia C. C. Steinbach, Fabio Fait, Hermann A. A. Mayer, Andreas Kandelbauer
Summary: This study focuses on the synthesis and properties of hybrid organic/inorganic nanocomposites. A quantitative model with high robustness and predictive power was established, demonstrating the complex nonlinear behaviors and partly synergistic interactions between process factors in determining the material properties.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Applied
Fabio Fait, Julia C. Steinbach, Andreas Kandelbauer, Hermann A. Mayer
Summary: Mesoporous silica microspheres (MPSMs) are prepared using p(GMA-co-EDMA) as hard templates with different porosity and surface functionalization. The incorporation of GMA into the template is determined by a PLS-R model based on FTIR spectra. Silica nanoparticles (SNPs) are deposited into the template and subsequently removed by calcination to form MPSMs with different pore parameters. The pore structure and separation properties of the silica particles are determined by the pore characteristics and functionalization of the template.
MICROPOROUS AND MESOPOROUS MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Dustin Quinones, Kai Braun, Steffen Ulitzsch, Tim Baeuerle, Gunter Lorenz, Andreas Kandelbauer, Alfred Meixner, Thomas Chasse
Summary: The film formation of self synthesized Polymer EPM-g-VTMDS on V2A stainless steel surfaces with adhesion promoter VTMS was studied. Polymer films were spin coated on surfaces with adsorbed VTMS thin layers to analyze the film formation at early stages. The surface topography and chemical bonding were investigated using various techniques, and the formation of polymer islands and the crosslinking and silica network in the films were observed.
Article
Food Science & Technology
Julia C. Steinbach, Dmytro S. Golovko, Andreas Kandelbauer, Karsten Rebner
Summary: Rapid and robust quality monitoring of meat paste composition is crucial in meat and sausage processing. In this study, an in-line near-infrared spectroscopy/MEMS-based approach combined with multivariate data analysis was used to measure the fat, protein, water, and salt constituents in meat pastes. High accuracy predictive PLSR models (R (2) > 0.81) were obtained by including salt content in the calibration set, considering interfering matrix effects of salt on the spectral features of meat pastes.
ACS FOOD SCIENCE & TECHNOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Fabio Fait, Stefanie Wagner, Julia C. Steinbach, Andreas Kandelbauer, Hermann A. Mayer
Summary: The hard template method has been used to prepare monodisperse mesoporous silica microspheres (MPSMs) with in situ-generated silica nanoparticles (SNPs) controlling the size and pore parameters. Different alkoxysilanes were sol-gel processed with amino-functionalized poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) (p(GMA-co-EDMA)) templates to determine the size of the deposited SNPs. The final MPSMs have a broad size range of 0.5-7.3 μm and a median pore size distribution from 4.0 to 24.9 nm, with adjustable specific surface area between 271 and 637 m^2 g^-1. The properties and morphology of the MPSMs vary with the type of SNPs, and different alkoxysilane combinations allow for individual design of the silica particles' morphology and pore parameters. Selected MPSMs were successfully used in high-performance liquid chromatography (HPLC) for the separation of water-soluble vitamins.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Biochemical Research Methods
Fabio Fait, Julia C. Steinbach, Andreas Kandelbauer, Hermann A. Mayer
Summary: High-performance liquid chromatography is a crucial analytical tool for identifying and separating substances. Monodisperse mesoporous silica microspheres (MPSM) are commonly used as stationary phases, but their tailored preparation is challenging. This study successfully synthesized four MPSMs using the hard template method. The size, morphology, and pore properties of the MPSMs were controlled by the solvent used during preparation, and they exhibited comparable separation behavior to commercially available columns in reversed-phase chromatography.
JOURNAL OF CHROMATOGRAPHY A
(2023)
Article
Chemistry, Multidisciplinary
Julia C. Steinbach, Fabio Fait, Hermann A. Mayer, Andreas Kandelbauer
Summary: Mesoporous silica microspheres (MPSMs) were synthesized using a hard template method to control particle size and pore properties. Response surface methodology was applied to predict the effects of synthesis parameters on MPSM characteristics. The prepared MPSMs were successfully applied as stationary phase for reversed-phases liquid chromatography, achieving protein and amino acid separation.
Article
Materials Science, Multidisciplinary
Latifeh Nasseri, Catherine Rosenfeld, Pia Solt, Matthias Mihalic, Andreas Kandelbauer, Johannes Konnerth, Hendrikus W. G. van Herwijnen
Summary: This study compares the gel point and crossover point of formaldehyde-based wood adhesives using the isothermal multiwave oscillatory shear test. Rheokinetic analysis shows no significant difference in activation energies between the gel point determined by the multiwave test and the crossover point obtained by the time sweep test.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Green & Sustainable Science & Technology
Tobias Drieschner, Andreas Kandelbauer, Bernd Hitzmann, Karsten Rebner
Summary: This study uses a design of experiment approach to characterize the transesterification reaction of rapeseed oil with methanol and utilizes process analytical technology (PAT) to gain insight into the process behavior.
JOURNAL OF RENEWABLE MATERIALS
(2023)
Article
Polymer Science
Regina Seidl, Stephanie Weiss, Edith M. Zikulnig-Rusch, Andreas Kandelbauer
Summary: By utilizing the response surface methodology with orthogonal parameter level variations, it is possible to quantify the effects of different factors during melamine-formaldehyde resin synthesis, find the most suitable reaction conditions, and obtain impregnation resins with favorable properties.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Chemistry, Physical
Nadine J. Kanik, Artur Kuligiewicz, Jeffrey T. Cullen
Summary: This study examined the effects of different pre-treatments on the structural H-isotope composition of clay minerals. The results showed that different pre-treatments had varied impacts on different clay minerals, and the choice of pre-treatment should be based on the specific properties and mineralogy of the samples.
APPLIED CLAY SCIENCE
(2024)
Article
Chemistry, Physical
Lorenzo Lisuzzo, Giuseppe Cavallaro, Stefana Milioto, Giuseppe Lazzara
Summary: This study proposes Pickering emulsions based on wax and halloysite clay nanotubes for coating silk sutures to increase their loading capacity towards eosin. The presence of halloysite/wax microspheres on the surface of silk sutures has also been explored for controlled release of hydrophobic drugs. The influence of the coating on the thermal and mechanical properties of the sutures has been studied using various techniques. In conclusion, the wax/halloysite Pickering emulsions can successfully generate hydrophobic microdomains on the surface of silk sutures, leading to enhanced flexibility and improved loading capacity towards eosin.
APPLIED CLAY SCIENCE
(2024)
Article
Chemistry, Physical
Bruna F. Alves, Rita C. P. Nunes, Luiz C. Bertolino, Elizabete F. Lucas
Summary: Operational problems in the oil industry caused by the precipitation of paraffins can be prevented by using polymeric additives. This article evaluates the use of polymeric nanocomposites as pour point reducers in different types of crude oil and finds that they are more efficient than pure poly(ethylene-covinyl acetate) (EVA) in reducing the pour point. The nanocomposites also modify the wax crystals and reduce the viscosity of the oil samples.
APPLIED CLAY SCIENCE
(2024)
Article
Chemistry, Physical
K. A. Daniels, C. C. Graham, A. C. Wiseall, J. F. Harrington, P. Sellin
Summary: Geological storage with clay buffer is widely preferred for removing hazardous radioactive waste. The impact of fluid salinity and void space on the swelling behavior of barrier bentonites was examined through experiments. The findings suggest that clay swelling is suppressed at higher salinities, which affects the void-filling process.
APPLIED CLAY SCIENCE
(2024)
Article
Chemistry, Physical
N. Werling, A. Kuligiewicz, A. Steudel, R. Schuhmann, F. Dehn, K. Emmerich
Summary: Thermal treatment of clay minerals can be used to produce building materials and environmentally friendly binders. This process involves dehydration, dehydroxylation, breakdown of structure, and recrystallization of high temperature phases. Rehydration and rehydroxylation are important factors to consider for geopolymers and SCM.
APPLIED CLAY SCIENCE
(2024)
Article
Chemistry, Physical
Xuan Wang, Hao Ding, Zhuoqun Xu, Jianmeng Zhang, Yanbin Yao
Summary: Rutile nano-TiO2 was loaded onto the surface of sericite to prepare sericite-rutile composite particles, which were then modified with HDTMS and sprayed onto the substrates to form sericite-rutile/HDTMS composite coatings with UV shielding and superhydrophobic self-cleaning properties. The coating exhibited good UV shielding rate and remained superhydrophobic after UV irradiation. The hierarchical structure of the sericite-rutile composite and the low surface energy of HDTMS contributed to the superhydrophobicity and UV shielding effect of the coating.
APPLIED CLAY SCIENCE
(2024)
Article
Chemistry, Physical
Kailang Sun, Taojun Zhang, Jie Zhou, Yonghong Liu, Minfeng Zeng, Zhen Yang, Ruokun Feng, Xiaorong Ren, Peng Zhang, Baoyi Wang, Xingzhong Cao
Summary: Chitosan-Pd0 nano particles encapsulated in Al, Co-pillared montmorillonite nanocomposites were successfully synthesized using a facile one-pot heat treatment method. The Al, Co pillaring effectively expanded the surface area and generated numerous mesopores in the interlayer space of the MMt. The resultant nanocomposite exhibited similar high comprehensive catalytic performances as the one prepared by the regular divided-multistep method. The encapsulation of CS chains and doping of Co in the Al pillaring also contributed to the improved catalytic performance.
APPLIED CLAY SCIENCE
(2024)
Article
Chemistry, Physical
Nathalie Fagel, Isabel Israde-Alcantara, Reza Safaierad, Marttiina Rantala, Sabine Schmidt, Gilles Lepoint, Pierre Pellenard, Nadine Mattielli, Sarah Metcalfe
Summary: Environmental conditions significantly influence clay minerals, and studying clay sediments in tropical lakes can provide valuable insights into past environmental conditions. In this study, multiproxy records from sediment cores of three crater lakes in central Mexico were analyzed. The results showed that disordered kaolinite, formed through hydrolysis and hydrothermal alteration, was the predominant mineral in the sediments. The abundance of kaolinite varied in relation to organic carbon and organic matter-related elements, and showed opposite trends with lithogenic elements. Geochemical data suggested that the increase in kaolinite abundance is linked to the formation of organo-mineral aggregates and lake level changes in closed basins.
APPLIED CLAY SCIENCE
(2024)
Article
Chemistry, Physical
M. J. Martin-Alfonso, A. Mejia, F. J. Martinez-Boza, P. Partal
Summary: The drilling industry is facing new challenges to develop eco-friendlier drilling fluids. Organic modified sepiolite dispersed in oil can be an excellent additive with suitable rheological properties. This study investigated the effect of alkyl ammonium modifiers on the microstructure and rheological properties of sepiolite-vegetable oil dispersions under high-temperature and high-pressure conditions.
APPLIED CLAY SCIENCE
(2024)
Article
Chemistry, Physical
Weiquan Zhan, Siyuan Yang, Shenxu Bao, Liuyi Ren, Cheng Liu
Summary: The interaction between talc and the depressor CMC was investigated through molecular dynamics simulation and density functional theory calculation. It was found that CMC showed stronger adsorption on the edge plane of talc due to enhanced interactions with polar groups and water molecules. The study also revealed specific interactions between H atoms in CMC and O atoms in the edge plane, as well as between O atoms in CMC and Si, Mg atoms in the edge plane. Hydration shells on the basal and edge planes of talc were examined to explain the phenomenon.
APPLIED CLAY SCIENCE
(2024)
Article
Chemistry, Physical
Pierre Dramou, Yiyang Sun, Xu Ni, Fangqi Wang, Hua He
Summary: In this study, a magnetic nanocomposite was prepared and used for the separation of rutin from real samples through magnetic solid phase extraction (MSPE). The nanocomposite exhibited high specific surface area, chemical and thermal stability, water solubility, and easy separation in aqueous solution. Characterization and experiments confirmed the successful synthesis and efficient enrichment ability of the nanocomposite.
APPLIED CLAY SCIENCE
(2024)