Thermal Analysis Techniques Research Articles

Sorbate metal complexes as newer antibacterial, antibiofilm, and anticancer compounds

BackgroundThe ineffectiveness of treatments for infections caused by biofilm-producing pathogens and human carcinoma presents considerable challenges for global public health organizations. To tackle this issue, our study focused on exploring the potential of synthesizing new complexes of Co(II), Cu(II), Ni(II), and Zn(II) with sorbic acid to enhance its antibacterial, antibiofilm, and anticancer properties.MethodsFour novel complexes were synthesized as solid phases by reacting sorbic acid with Co(II), Cu(II), Ni(II), and Zn(II). These complexes were characterized by various technique, including infrared spectra, UV–Visible spectroscopy, proton nuclear magnetic resonance (1H NMR), and thermal analysis techniques, including thermogravimetry (TG).ResultsThe data acquired from all investigated chemical characterization methods confirmed the chemical structure of the sorbate metal complexes. These complexes exhibited antibacterial and antibiofilm properties against both Gram-positive and Gram-negative bacteria. Furthermore, these complexes enhanced the antibacterial effects of commonly used antibiotics, such as gentamicin and imipenem, with fractional inhibitory concentration (FIC) indices ≤ 0.5. Notably, the Cu(II) complex displayed the most potent antibacterial and antibiofilm activities, with minimum inhibitory concentration (MIC) values of 312.5 µg/mL and 625.0 µg/mL for Bacillus cereus and Escherichia coli, respectively. Additionally, in vitro assays using the methyl thiazolyl tetrazolium (MTT) method showed inhibitory effects on the growth of the human colon carcinoma cell line (HCT-116 cells) following treatment with the investigated metal complexes. The IC50 values for Co(II), Cu(II), Zn(II), and Ni(II) were 3230 µg/mL, 2110 µg/mL, 3730 µg/mL, and 2240 µg/mL, respectively.ConclusionOur findings offer potential for pharmaceutical companies to explore the development of novel combinations involving traditional antibiotics or anticancer drugs with sorbate copper complex.

Energy-safety balanced composites of attractive cyclic nitramines with polyaniline

Composite microcrystals of the cyclic nitramines 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-CL-20), 1,3,5-trinitro-1,3,5-triazinane(RDX), 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (β-HMX), and cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole (BCHMX) with polyaniline (PANi) have been prepared and thoroughly characterized in terms of morphology and phase purity. PANi outperformed other conducting polymers in terms of selectivity towards NAs due to its better interaction with NAs, low production cost, and ease of preparation. The bonding of nitramines with the polymeric PANi chain has been examined by means of Fourier transform infrared (FTIR), Raman spectroscopy methods, and fluorescence quenching; the Raman spectrum has shown the laser sensitivity of these microcrystals. Powder X-ray diffraction results have shown changes in polymorph modifications in CL20 (from ɛ to β) and HMX (from β to α) during the preparation of the composites, which have also been confirmed by spectral and differential thermal analysis techniques. The structural orientations found in these composites significantly stabilize nitramines against impact; their detonation properties have slightly deteriorated, but the PANi electrical conductivity has strongly increased their electric-spark sensitivity. The above properties of the prepared composites determine their potential use mainly as parts of the electric or laser impulse initiators, having “a green character”, for various charges.

Syntheses, characterizations and photochromic properties of 1D→2D polycatenated cationic coordination polymers based on the flexible tripodal zwitterionic ligand

Two new coordination compounds, namely, {[ZnBr(µ3-tazna)]NO3·4H2O}n (1) and {[CdBr(µ3-tazna)]ClO4·2H2O}n (2) were solvothermally synthesized from the 1,1′,1′′-(((1,3,5-triazin-2,4,6-triyl)tris(benzene-4,1-diyl))tris(methylene))tris(3-carboxypyridin-1-ium) bromide (H3taznaBr3) ligand and characterized by IR spectroscopy, elemental analysis, X-ray single-crystal diffraction, X-ray powder diffraction (PXRD), and thermal analyses techniques. Single-crystal X-ray diffraction analysis reveals that compounds 1 and 2 crystallize in the triclinic system, P-1 space group. In 1 and 2, Zn(II) and Cd(II) centers are bridged by tazna ligands, displaying a rare 1D → 2D structure formed by the catenation of a 1D double chain. The photochromic behavior of compound 2 was investigated under 365 nm UV light, exhibiting a color change from white to yellow. Furthermore, the thermal and optical absorption properties of compounds 1 and 2 were investigated.

Thermal Studies of Fractionated Lignite and Brown Coal Fly Ashes.

Coal fly ash (CFA), a by-product of coal combustion, is a valuable raw material for various applications. However, the heterogeneous nature of the composition and properties of CFA provides challenges to its effective usage and utilisation. This study investigates the thermal behaviour of the fly ashes of lignite (FA1) and brown coal (FA2) and their fractions obtained by dry aerodynamic separation. Thermal analysis techniques, including thermogravimetry (TG), differential scanning calorimetry (DSC), and evolved gas analysis (EGA), were used to characterise the behaviour of the fly ash fractions while heating up to 1250 °C. The results reveal distinct differences in the thermal behaviour between ash types and among their different size fractions. For the FA1 ashes, the concentration of calcium-rich compounds and the level of recrystallisation at 950 °C increased with the decrease in particle size. The most abundant detected newly formed minerals were anhydrite, gehlenite, and anorthite, while coarser fractions were rich in quartz and mullite. For the FA2 ashes, the temperature of the onset of melting and agglomeration decreased with decreasing particle size and was already observed at 995 °C. Coarser fractions mostly remain unchanged, with a slight increase in quartz, mullite, and hematite content. Recrystallisation takes place in less extension compared to the FA1 ashes. The findings demonstrate that the aerodynamic separation of fly ashes into different size fractions can produce materials with varied thermal properties and reactivity, which can be used for specific applications. This study highlights the importance of thermal analysis in characterising fly ash properties and understanding their potential for utilisation in various applications involving thermal treatment or exposure to high-temperature conditions. Further research on advanced separation techniques and the in-depth characterisation of fly ash fractions is necessary to obtain materials with desired thermal properties and identify their most beneficial applications.

Bio-based materials in tribology: New salicylate ionic liquid+ZnO nanolubricant of PLA and PLA nanocomposite

ZnO nanoparticles have been dispersed (in 0.05; 0.5 and 1.0 wt% proportions) in the protic ionic liquid bis(2-hydroxyethyl) ammonium salicylate (DSa) to obtain new (DSa+ZnO) nanofluids. A non-Newtonian behavior was found for ZnO concentrations lower than 1 wt%. The Newtonian DSa+ 1 wt%ZnO nanofluid was selected as lubricant of polylactic acid (PLA) and as 5 wt% additive to obtain the new PLA+ (DSa+ZnO) nanocomposite. PLA+ZnO was also studied as a reference. The excellent friction-reducing and antiwear behavior of PLA+ (DSa+ZnO) is attributed to the porosity that promotes self-lubrication and to synergy due to interactions between the salicylate anion in DSa and the surface of ZnO nanoparticles. Electron microscopy (SEM and TEM), Raman spectroscopy, thermal analysis (DSC and TGA) and profilometry techniques were used.

Determining phase-transition temperatures of molten salt mixtures through microsecond-scale staircase voltammetry

Determining the phase-transition temperature is crucial in the design of molten salt reactors, as operational temperatures need to be established considering the safety margins related to the thermodynamic stability of the molten salt system. This study introduces a novel approach to determine the phase-transition temperature based on rapid electrical conductivity measurements using a microsecond-scale staircase voltammetry technique. The phase-transition temperature is determined near distinct points where the electrical conductivity abruptly changes, indicating phase transitions. The phase-transition temperatures of three LiCl–KCl molten salt systems, determined using the proposed approach based on electrical conductivity measurements, are with relative errors less than 3% compared with reported phase transition data based on conventional thermal analysis techniques.

Challenges by latent heat calculation – Competition among analytical and computational methods

Determining the latent heat of multi-component cast aluminum alloys is complex. These alloys solidify within the mushy zone, with their latent heat release influenced by factors like composition, cooling rate, and microstructure. Techniques such as DSC and DTA, along with software tools like JMatPro, FactSage, and ThermoCalc, can determine this value, understand solidification parameters, and calculate latent heat. This paper introduces a novel approach using Newtonian, Fourier, and Energy Balance methods simultaneously, for the first time, to calculate the latent heat of pure aluminum and its AlSi7Cu1 alloy. These methods offer advantages in foundry conditions and require no specialized operator for data interpretation. Commercial software typically provides parameters for standard alloys only, necessitating alternative sources for accurate data. Thermal analysis techniques offer a reliable method to acquire missing parameters and calculate latent heat with high precision. Comparing the accuracy of these methods for pure aluminum and its AlSi7Cu1 alloy, using DSC measurement data and commercial software values, indicates successful application on the foundry floor to determine thermophysical properties accurately.

Exploring New Schiff Bases: Synthesis, Characterization, and Multifaceted Analysis for Biomedical Applications.

The current work aims to generate novel Schiff bases by reacting substituted aldehydes with amine derivatives catalyzed by a natural acid. The developed compounds underwent diverse physicochemical analyses including liquid chromatography-mass spectrometry, Fourier transform infrared spectroscopy, scanning electron microscopy, 1H- and 13C-nuclear magnetic resonance, and X-ray diffraction. Furthermore, differential thermogravimetric, thermogravimetric, and differential thermal analysis techniques were employed in a nitrogen-free environment to determine kinetic parameters. These data were then used in model-free isoconversional methods (e.g., Friedman, Kissinger-Akahira-Sunose, and Flynn-Wall-Ozawa). The Schiff bases were evaluated for their in vitro and in silico α-amylase inhibitory activity. Schiff base-2 displayed the highest inhibition compared with the reference drug acarbose. In comprehensive MTT assay cytotoxicity investigations, both Schiff bases showed strong anticancer capabilities against the human lung cancer cell line (A549). Moreover, this study demonstrated effectiveness of synthetic compounds in screening Caenorhabditis elegans for anti-Alzheimer's and stress resistance properties. The simplicity of its biology allowed precise evaluation of the effect of compounds on neuronal function and stress response. This research enhances drug discovery efforts for Alzheimer's and stress-related disorders, potentially improving patient outcomes.

Characterization and utilization capabilities of industrial wastes for green bricks production

BackgroundThe goal of this study is to develop a feasible and sustainable solution to manage the use of industrial wastes of ground granulated blast-furnace steel slag (GGBS) activated by cement kiln dust (CKD) and quicklime (QL). Using activated GGBS in the manufacture of stabilized green bricks is still uncommon in Egypt in such applications. Five clay-based mixtures, each with varying replacement ratios (5–10, wt.%) of CKD and QL, were studied. Laboratory tests were conducted on cylindrical specimens made from these mixtures, which were left to cure for periods of up to 60 days. The raw materials and lab-made specimens were analyzed using particle size analysis, differential thermal analysis, X-ray fluorescence, and X-ray diffraction techniques. The physical and mechanical properties of the cured specimens were also determined and evaluated according to standard specifications. Furthermore, the durability of the cured specimens was evaluated against collapsibility in water.ResuItsIt has been observed that adding QL and CKD to the stabilized green specimens of different mixes can enhance their engineering properties with curing age increasing. This is due to the pozzolanic reaction, which fills the pore structure with calcium silicate hydrates and calcium aluminate hydrates gel. The ratio of QL and CKD used significantly affected the engineering properties of the specimens. The study found that using 20% GGBS and 5% QL led to an increase in compressive strength (266 kg/cm2) at the density of (2.15 g/cm3), while also water absorption was reduced (8%) to give superior results. When GGBS and CKD were combined, a higher content of CKD (10 wt.%) gave better results compared to (5 wt.%) CKD. Furthermore, the physical and mechanical properties of the tested specimens (MD 1, MD II, MD III and MD IV) met the acceptable limits of dry compressive strength (30–70 kg/cm2), water absorption (8–15%), and density (1.7–2 gm/cm3), as specified by the Egyptian standard specifications for buildings used compressed earth blocks.ConclusionThe CKD and QL act as alkali activators for GGBS and can be utilized in masonry construction.

Highly efficient electrocatalytic degradation of methylparaben using BiOx-doped Ti/β-PbO2 anode: Comprehensive electrochemical study and degradation mechanism

Electrochemical degradation of methylparaben (MPB) was successfully performed using Ti/β-PbO2-BiOx anode. The structure of the fabricated electrode was characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and mapping techniques. The results confirmed the successful preparation of the electrode with favorable morphological and structural properties. This research includes optimization of operating parameters such as solution pH, applied current density, initial MPB concentration and electrolysis time. The results indicate that the prepared electrode has high electrochemical performance and thermal stability. Under optimal conditions, current density of 4.8 mA/cm2, pH = 5 and initial concentration of 0.5 mM, the maximum degradation efficiency of 98.9 % was obtained. In this work, also, based on the data obtained from LC-MS analysis, a detailed mechanism for the degradation of MPB was proposed. In another section of this research, the electrochemical behavior of MPB on glassy carbon electrode was comprehensively studied using cyclic voltammetry at different pH values. The data obtained from this study provide significant insight into the electrochemical behavior of MPB, its pH-dependent properties and adsorption activities. The results of this section can also be used to better optimize the conditions of MPB degradation.

Study on the curing characteristics and properties of phthalonitrile resin cured with organic guanidine

Bisphenol A-based phthalonitrile resin was synthesized by nucleophilic substitution reaction from bisphenol A and 4-nitrophthalonitrile, and then the obtained resin was cured with sulfaguanidine as a novel curing agent. The curing characteristics, kinetics, thermal stability and dynamic mechanical property were studied by standard thermal analysis techniques including DSC, TGA, and DMA. The peak temperature of exothermic peak ( Tp) and apparent activation energy ( Ea) of sulfaguanidine cured phthalonitrile resin were 263.20°C and 76.6 kJ·mol−1 respectively, much lower than those of traditional aromatic diamine cured resin. Moreover, the resin cured by sulfaguanidine showed excellent thermomechanical properties and thermal stability. The glass transition temperature ( Tg) was 284.8°C, the initial thermal decomposition temperature ( Td,5%) was 439.6°C, and the char yield at 800°C was 62.1% in nitrogen atmosphere. To sum up, organic guanidine cured phthalonitrile resin exhibits excellent curing characteristics (low Tp and Ea) and high thermal properties, which provides a promising approach to preparing phthalonitrile resin with high comprehensive performance.

Impact of Cations and Framework on Trapdoor Behavior: A Study of Dynamic and In Situ Gas Analysis.

Due to their distinct and tailorable internal cavity structures, zeolites serve as promising materials for efficient and specific gas separations such as the separation of /CO2 from N2. A subset of zeolite materials exhibits trapdoor behavior which can be exploited for particularly challenging separations, such as the separation of hydrogen, deuterium, and tritium for the nuclear industry. This study systematically delves into the influence of the chabazite (CHA) and merlinoite (MER) zeolite frameworks combined with different door-keeping cations (K+, Rb+, and Cs+) on the trapdoor separation behavior under a variety of thermal and gas conditions. Both CHA and MER frameworks were synthesized from the same parent Y-zeolite and studied using in situ X-ray diffraction as a function of increasing temperatures under 1 bar H2 exposures. This resulted in distinct thermal responses, with merlinoite zeolites exhibiting expansion and chabazite zeolites showing contraction of the crystal structure. Simultaneous thermal analysis (STA) and gas sorption techniques further demonstrated how the size of trapdoor cations restricts access to the internal porosities of the zeolite frameworks. These findings highlight that both the zeolite frameworks and the associated trapdoor cations dictate the thermal response and gas sorption behavior. Frameworks determine the crystalline geometry, the maximum porosities, and displacement of the cation in gas sorption, while associated cations directly affect the blockage of the functional sites and the thermal behavior of the frameworks. This work contributes new insights into the efficient design of zeolites for gas separation applications and highlights the significant role of the trapdoor mechanism.

Structure-performance relationship of polypropylene/elastomer/carbon black composites as high voltage cable shielding layer

As polypropylene (PP) is a competitive insulating material for next generation high-voltage cable, the corresponding PP based cable semi-conductive shielding layer material needs to be developed. This paper developed an excellent material prescription and proposed an analytical method of structure-performance relationship for the application and the evaluation of PP-based cable shielding layer. First, PP/POE/CB and PP/SEBS/CB composites with different carbon black (CB) loading were prepared and their electrical and mechanical properties were compared. Through thermal analysis technique, crystalline property and thermal stability of the composites were studied in detail. And the synchrotron radiation X-ray scattering techniques were employed to analyze the distribution of carbon black in the blend semi-quantitatively. The analysis result turns out the enrichment of carbon black in POE phase and its instability at high temperature limits its application under cable operation conditions. In contrast, PP/SEBS/CB30phr is recommended for lower thermal deformation, lower PTC effect and better mechanical parameters.

1D heteronuclear coordination polymers of hexacyanocobaltate(III) with 2-hydroxymethylpyridine

Three new hexacyanocobaltate(III) complexes, {[M2(hmpy)4Co(µ-CN)4(CN)2]∙2H2O}n (M = Cu(II) (1), Zn(II) (2) and Cd(II) (3)) were synthesized with 2-hydroxymethylpyridine (hmpy) ligand, and characterized by vibration (FT-IR and Raman) spectral, single crystal X-ray diffraction (SC-XRD) and powder X-ray diffraction (PXRD), thermal and elemental analyses techniques. The crystallographic analyses revealed that cyanide complexes 1–3 are infinite one-dimensional coordination polymers. Each M ion is coordinated by two nitrogen and two oxygen atoms from the hmpy ligands and two nitrogen atoms from the cyanide ligands, displaying a distorted octahedral coordination geometry. Similarly, each Co(III) ion is coordinated by six carbon atoms from cyanide ligands to form a distorted octahedral coordination geometry. These complexes form 3D supramolecular networks through OH···O hydrogen bonds and CH···N interactions. Additionally, structural analyses such as metal salts, pH values of the compounds obtained under different conditions were evaluated. A synthesis-structural analyses relation was made from these data.

Analysis of high temperature phase transformation behavior of ultra-low-carbon steel using X-ray topography, diffraction, and synchronized temperature measurement

Despite the technical importance of δ/γ phase transition in steel alloys, conventional thermal analysis techniques like calorimetry lack precise kinetics measurement. This study introduces an integrated approach combining X-ray topographic imaging, diffraction, and precise temperature measurement to overcome these limitations. This methodology allows for the accurate quantification of recalescence due to release of latent heats from solidification and solid-state phase transformation. It also enables tracking of the fractional volume changes of the δ phase during continuous cooling. We demonstrate that in Ultra-Low Carbon steels, the δ to γ transformation occurs rapidly in the single γ phase region far below the solidus temperature in the phase diagram, and this transformation accelerates further in the higher cooling rate. Furthermore, it can be inferred that in phase transformation, its rate becomes a critical factor in the temperature increase resulting from the released latent heat, overshadowing the influence of undercooling during continuous cooling.

Photocatalysis and antimicrobial activity of ZnO@TiO2 core-shell nanoparticles

Wet chemical synthesis was used in this instance to create ZnO@TiO2 core-shell nanoparticles. By examining X-ray diffraction and Selected Area Electron Diffraction patterns, it was determined that the phase formation of prepared nanoparticles was a hexagonal primitive structure of ZnO and Tetragonal bcc structure of anatase phase of TiO2 devoid of impurity peaks. It was discovered that crystallites were 25 nm in size on average. The results of a surface morphology analysis utilizing High-Resolution Scanning Electron Microscopy and High-Resolution Transmission Electron Microscopy show that all of the particles are spherical. The energy dispersive X-ray spectroscopy study provided proof for the existence of core-shell elemental compositions. Fourier-Transform Infrared spectrum revealed the presence of characteristics of metal bonding with oxygen of ZnO and TiO2. UV-visible absorption analysis exhibited absorption peak in the UV region and the band gap energy of ZnO@TiO2 core-shell nanoparticles. The thermal behavior of ZnO@TiO2 core-shell nanoparticles was analyzed by using Thermogravimetric Analysis, Differential scanning calorimetry, and Differential Thermal Analysis techniques. The X-ray photoelectron spectroscopy analysis exhibited the coating of TiO2 (shell) on the surface of ZnO (core) for the formation of a core-shell nanostructure. Due to its extremely small crystallite size, wide surface area, and reduced band gap, the ZnO@TiO2 core-shell sample demonstrated outstanding photocatalytic activity when rhodamine-B dye was photocatalytically degraded in the presence of UV light irradiation. Finally, the antibacterial and antifungal activities of ZnO@TiO2 core-shell nanoparticles were investigated, and it was shown that antifungal activity was superior to antibacterial activity. A suitable material for environmental and biological applications that produced core-shell nanoparticles displayed regulated grain size, outstanding photocatalytic performance, and high antifungal activity.

Comprehensive Understanding of the Heavy Oil Combustion Process: Reaction Behavior, Kinetic Triplet, and Mechanism Implication.

In this work, thermo-oxidative behavior, kinetic triplet, and free radical mechanism of ultraheavy oil during an in situ combustion (ISC) process were systematically surveyed via multiple thermal analysis techniques (TG/DTG/DSC/PDSC), model-free methods, and related mathematical simulation. First, specific mass loss, exothermic intensity, and corresponding temperature intervals were respectively determined in low-/high-temperature oxidation (LTO/HTO) regions. In addition, the comparison of atmospheric/pressurized differential scanning calorimetry (DSC/PDSC) experiments indicated that the pressurized conditions could obviously strengthen the oxidation progress with more heat emission. Then two model-free methods were contrastively employed for PDSC data to calculate LTO and HTO activation energy variations with the conversion rate. Moreover, the acceleratory rate model for LTO and the Sestak-Berggren model for HTO were accordingly picked as the most probable mechanism functions, which were later used to determine the simulated curves. Then, the simulations of α-T and dα/dT-T curves were respectively attained using Friedman equation in MATLAB software and contrasted with experimental data to validate the accuracy of the yielded kinetic triplet and forecast the combustion behavior. Further, the evolution pathways of the underlying oxidation mechanism was illustrated. This study updates the understanding of the nonisothermal combustion process, contributing to the subsequent numerical simulation and feasible investigation for in situ combustion implementation to enhance heavy oil recovery.

Anti-proliferative, antimicrobial, DFT calculations, and molecular docking 3D scaffold based on sodium alginate, chitosan, neomycin sulfate and hydroxyapatite

3D multifunctional scaffold has been designed based on Cs/SA/NS/NPHA. Nanoparticles hydroxyapatite (NPHA) was prepared via precipitation method of sodium dihydrogen phosphate in presence calcium chloride. Different ratios of Chitosan (CS)/Sodium Alginate (SA) were used to prepare Cs/SA scaffolds in presence of CaCl2 as a cross linker. NPHA was incorporated in CS/SA scaffold and neomycin sulfate (NS) was added as an antimicrobial agent. The structure and surface morphology of the scaffolds were investigated via infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermal gravimetric analysis (TGA) techniques. Additionally, Antimicrobial activity of the scaffold has evaluated against Gram- negative and Gram- positive bacteria. The result showed promising antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. Furthermore, cytotoxicity against MG63 osteosarcoma cell and fibroblast normal cell line has investigated. The result showed anti-proliferative against MG63. DFT calculations and molecular docking were used to study the reactivity of the compounds. The results exhibited that Cs/SA/NS/NPHA is potent expected to be used in bone tissue regeneration.

Application of Model-Free and Model-Based Kinetic Methods in Evaluation of Reactions Complexity during Thermo-Oxidative Degradation Process: Case Study of [4-(Hydroxymethyl)phenoxymethyl] Polystyrene Resin

This work examined the possibilities and limitations of model-free and model-based methods related to decrypting the kinetic complexity of multi-step thermo-oxidative degradation processes (as a testing system, a [4-(hydroxymethyl)phenoxymethyl] polystyrene resin was used), monitored by thermal analysis (TGA-DTG-DTA) techniques. It was found that isoconversional methods could successfully determine the correct number of process stages and presence of multiple reactions based on derived Ea(α) profiles and identify the negative dependence of the rate constant on the temperature. These methods could not overcome the problem that arose due to mass transfer limitations. The model-based method overcame more successfully the problem associated with mass transfer because its calculation machinery had capabilities for the correct solution of the total mass balance equation. However, a perfect fit with the experimental data was not achieved due to the dependence on the thermal history of the contribution (ctb.) of a given reaction step inside a fitting procedure cycle. On the other hand, through this approach, it was possible to estimate the rate-controlling steps of the process regarding the influence of the heating rate. It was found that for consecutive reaction mechanisms, the production of benzaldehyde and gases in high yields was controlled by the heating rate, where low heating rates were strongly recommended (≤10 K/min). Also, it was shown that the transport phenomenon may be also the rate-determining step (within the set of “intrinsic” kinetic parameters). It was also established that external heat transfer controls the overall rate, where the “pure” kinetic control regime had not been reached but was approached when lowering the temperature and size of the resin particles.

Analyzing Sustainable 3D Printing Processes: Mechanical, Thermal, and Crystallographic Insights.

In this study, the objective was to optimize energy consumption in the fused deposition modeling (FDM) 3D printing process via a detailed analysis of printing parameters. By utilizing thermal analysis techniques, this research aimed to identify lower printing temperatures that could lead to reduced energy usage. Experimental analysis was conducted using a three-level L9 Taguchi orthogonal array, which involved a systematic combination of different extruder temperatures and cooling fan capacities. Furthermore, the research incorporated differential scanning calorimetry (DSC) and X-ray diffraction (XRD) methods to analyze the thermal properties and crystallinity of the 3D-printed specimens. The results indicated that temperature was a key factor affecting crystallinity, with samples printed at 190 °C and 60% fan capacity showing the highest mean values. By conducting a multi-objective desirability analysis, the optimal conditions for maximizing ultimate tensile strength (UTS), tensile modulus, and elongation at break while minimizing energy consumption for PLA 3D-printed samples were determined to be a temperature of 180 °C and a fan speed of 80%.