Thermochimica Acta最新文献

{"title":"Pyrolysis of folic acid: Identification of gaseous/volatile products and structural evolution of N-doped graphitic carbon","authors":"Vagner R. Magri ,&nbsp;Caroline S. de Matos ,&nbsp;Michele A. Rocha ,&nbsp;Christine Taviot-Gueho ,&nbsp;Vera R.L. Constantino","doi":"10.1016/j.tca.2024.179813","DOIUrl":"10.1016/j.tca.2024.179813","url":null,"abstract":"<div><p>Folic acid (FA) is a low-cost and suitable source for producing different N-doped carbon materials by pyrolysis. However, the pyrolytic steps of FA are not entirely understood, particularly above 350 °C, which hampers the intelligent design of tailor-made carbon materials by a one-pot route. In this work, the pyrolytic decomposition steps of FA were investigated by simultaneous thermogravimetric analysis (TGA) and differential scanning calorimetry (TGA-DSC). The released gaseous/volatile products were probed by coupling TGA to infrared spectroscopy and mass spectrometry (TGA-FTIR-MS). Considering the thermal analysis data, FA was pyrolysed in a furnace at 350, 430, 570, 800, and 1000 °C, and the products were analysed by X-ray diffractometry (XRD), vibrational spectroscopy, and X-ray photoelectron spectroscopy. <em>In situ</em> high-temperature X-ray diffractometry (HT-XRD) experiments were also conducted under the nitrogen atmosphere. According to the data set, insights about FA decomposition steps could be proposed, including gaseous/volatile products released during the process and the structural evolution of N-doped graphitic carbon. The formation of carbonaceous material initiated between 200 and 350 °C through polymerisation/condensation reactions, and this step was marked by the release of 2-pyrrolidone and aniline. The graphitisation was enhanced above 350 °C, increasing graphitic nitrogen while the amide groups vanished. The process was accompanied by deoxygenation (i.e., CO and CO₂ release) and denitrogenation (e.g., NH₃, HNCO, and HCN) reactions. In the 570–800 °C range, the N-enrichment of carbon material (N-pyridine, N-pyrrole/Csp²-N in 5,7-membered rings, and nitrile) could occur by the reaction of released NH₃ over the char surface. Graphitic-like structures containing mainly N-graphite and N-pyridine were obtained above 800 °C. The original data about the thermal decomposition steps of FA allow for optimising the synthesis of N-doped carbon materials suitable for applications in adsorption, sensing, catalysis, and energy storage.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179813"},"PeriodicalIF":3.1,"publicationDate":"2024-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141694548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the thermal decomposition kinetics of ammonium carbamate for low-grade heat utilization","authors":"Suzhou Dai ,&nbsp;Yonggao Yin ,&nbsp;Yikai Wang ,&nbsp;Bowen Cao ,&nbsp;Maurizio Peruzzini ,&nbsp;Francesco Barzagli","doi":"10.1016/j.tca.2024.179809","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179809","url":null,"abstract":"<div><p>The thermochemical reaction of ammonium carbamate (AC) holds significant potential for low-grade heat utilization. However, the insufficient understanding of reaction kinetics limits its further applications. Therefore, a detailed study on the kinetic mechanism of AC decomposition was conducted using both the model-free and model-fitting thermal analysis methods with kinetic data from multiple heating program experiments. The results obtained from various methods are consistent, supporting the concept that AC decomposition is a single-step controlled multi-step reaction. The activation energy <em>E</em>, preexponential factor <em>A</em>, and most probable reaction model were determined to be 56.38 kJ∙mol⁻¹, 2.75 × 10⁶ s⁻¹, <em>f</em>(<em>α</em>)=(1-<em>α</em>)^0.7811, respectively. The reaction mechanism can be hypothesized as involving the rapid generation of numerous nucleation sites on the surface of solid AC, where surface reactions occur, with the movement of reaction interface governing the reaction rate. Consequently, a kinetic equation accounting for the AC decomposition was developed and evaluated, and the heat absorption specific power under different temperature conditions was predicted.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179809"},"PeriodicalIF":3.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Valorization of a high-sulfur petroleum coke for energy and fuels through its co-processing with a forest waste, using concrete wastes for sulphur and carbon dioxide capture under mild conditions","authors":"D. Vamvuka,&nbsp;K. Zacheila","doi":"10.1016/j.tca.2024.179811","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179811","url":null,"abstract":"<div><p>Current work provided a comprehensive assessment on the pyrolysis, combustion and gasification of a high-sulfur pet coke (PEC) and its blends with a forest waste (FOP). The potential of waste concrete fractions to capture SO₂ and CO₂ emissions was explored. The experiments were conducted in a fixed bed system and a thermogravimetric-mass spectrometric unit. Thermal behavior, reactivity, conversion, synergy, structural and chemical characteristics of solid materials, quantitative analysis of products and heating value, chemical, mineralogical and fusibility analysis of ashes were studied as a function of temperature, blending ratio and sorbent/fuel ratio. Addition of sorbent at a ratio Ca/<em>S</em> = 2 resulted in a desulfurization extent of 76–81 % during combustion. Quarry dust sorbent captured up to 95.4 % of CO₂ emitted below 700 °C. At 1000 °C H₂ content was 64.8–72.9 % mol and syngas yield 1.1–1.8 m³/kg. The gasification performance of PEC was improved upon blending with FOP.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179811"},"PeriodicalIF":3.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Supertoughened biodegradable poly(L-lactic acid) by multiphase blends system: Crystallization, rheological and mechanical properties","authors":"Yujie Jin ,&nbsp;Jing Guo ,&nbsp;Hongda Cheng ,&nbsp;Yi Li ,&nbsp;Changyu Han","doi":"10.1016/j.tca.2024.179810","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179810","url":null,"abstract":"<div><p>To toughen brittle poly(L-lactic acid) (PLA), poly(3-hydroxybutyrate-<em>co</em>-3-hydroxyhexanoate) (PHBH) and poly(vinyl acetate) (PVAc) were introduced into PLA matrix to prepared PLA/PHBH/PVAc ternary blends. PVAc was electively located in PLA matrix and refined phase morphology owing to better miscibility of PVAc with PLA than with PHBH. Increase in PVAc content decreased the crystallization rate and the crystallinity of PLA due to the dilution effect. More importantly, prominent enhancement of flexibility and toughness of PLA was obtained by the addition of PHBH and PVAc. Elongation at the break and impact strength of ternary blend with 10 wt% PVAc were 277 % and 326 % higher than that of neat PLA. Melt viscoelasticity of PLA was improved by incorporation of PHBH and PVAc. The combination of increased toughness and high melt viscoelasticity established in PLA biodegradable blends represent properties required in a wider range of applications.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179810"},"PeriodicalIF":3.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Addressing co-occurring conditions in behavioural therapy for tic disorders: a review and guideline.","authors":"Charlotte Sanderson, Cara Verdellen, Nanette Debes, Zsanett Tárnok, Jolande van de Griendt, Sharon Zimmerman-Brenner, Tara Murphy","doi":"10.1007/s00787-022-02097-1","DOIUrl":"10.1007/s00787-022-02097-1","url":null,"abstract":"<p><p>Co-occurring psychiatric conditions are very common in tic disorders and Tourette syndrome. These additional symptoms are often detrimental to quality of life and may impact upon the implementation and efficacy of evidence-based behavioural therapies (BT) for tics. Combining a review of the available literature, relevant theory, and expert clinical practice, we present a guideline for implementing behavioural and psychosocial interventions when common comorbidities are present. These include attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), anxiety, disruptive behaviour, autism spectrum disorder (ASD) and depression. Practical recommendations are provided for assessment, formulation and management of specific and multiple comorbidities in BT for both children and adults. Despite comorbidities being common in tic disorders, few studies have comprehensively addressed how they may influence the efficacy or implementation of existing therapies or how such treatments may need to be modified or sequenced. We outline recommendations for future research, including randomised control trials of BT for those with specific or multiple comorbidities, as well as adequately powered sub-group analyses within larger scale trials or naturalistic study designs. Transdiagnostic models of psychiatric disorders and treatment, including modular cross-diagnostic therapies, which recognise the dimensionality of psychiatric disorders are also highlighted as an important focus in treatment development in tic disorders.</p>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"501 1","pages":"2111-2127"},"PeriodicalIF":6.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77057459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photopyroelectric Techniques for Thermal Diffusivity and Optical Absorption Coefficient Measurements of SiO2 Colloids","authors":"C. Proa-Coronado,&nbsp;J.A. Balderas-López,&nbsp;Y. Sánchez-Fuentes,&nbsp;L.A. Linares-Duarte,&nbsp;E. Hernández-Sánchez","doi":"10.1016/j.tca.2024.179806","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179806","url":null,"abstract":"<div><p>In this work Photopyroelectric Techniques for thermal and optical characterization are introduced for measuring thermal diffusivity and optical absorption coefficient of colloidal suspensions of SiO₂. Thermal diffusivity and Optical absorption coefficients at 904 nm, 940 nm, 980 nm and 1550 nm were measured for spherical SiO₂ colloidal suspensions of 61 and 673 nm average size, in a range of 1 mg/mL to 26 mg/mL. It was found a linear increment of this optical property with SiO₂ nano-spheres concentration, which was not possible to obtain by means of absorbance measurements with conventional UV-Vis spectroscopy; in relation with thermal diffusivity it was found a slightly increment of this thermal property with increasing concentration, however this increment was not as large as the one reported for similar samples but using experimental techniques involving the optical properties of the samples. The direct measurement of optical absorption coefficients of colloidal suspensions allowed the knowledge of their absorptivity at the selected wavelengths. The presented methodology could be useful for measuring this optical property for colloidal suspensions in general at other wavelengths and as a function of other variables of interest, such as size particle.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179806"},"PeriodicalIF":3.1,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141596897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microcalorimetric study of the bactericidal action of titanium tetrachloride on the Pseudomonas aeruginosa growth. Potential implications in orthopaedic surgery","authors":"Ricardo Aveledo ,&nbsp;Natividad Lago ,&nbsp;Marta M. Mato ,&nbsp;José L. Legido","doi":"10.1016/j.tca.2024.179807","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179807","url":null,"abstract":"<div><p>With the rising use of metallic implants worldwide, bacterial infection has become a major concern due to its significant impact on patient health and national healthcare budgets. This study aimed to evaluate the sensitivity of <em>Pseudomonas aeruginosa</em>, a common bacterium responsible for implant surgery infections, to different concentrations of titanium tetrachloride (TiCl₄) solutions. Microcalorimetry was used to analyze the heat output produced by bacteria metabolism when exposed to TiCl₄ at concentrations ranging from 0 to 10 mM, as well as a saturated solution. The inner chamber of the calorimeter was set to the physiological temperature of the human body (309.65 K), and the heat output produced by bacteria metabolism was collected at intervals of 22.2 s for 48 h using a data acquisition and processing system. The data was then represented as thermograms. The results showed that higher concentrations of TiCl₄ had a bactericidal effect on the growth of <em>Pseudomonas aeruginosa</em>. This study supports the potential use of higher concentrations of this compound in surgical implants to reduce the risk of infection development due to its bactericidal properties.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179807"},"PeriodicalIF":3.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0040603124001461/pdfft?md5=e7abee9fb7f174ac361e12fb3464e152&pid=1-s2.0-S0040603124001461-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141540313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Manipulation of non-isothermal crystallization kinetics of poly(lactic acid) composite film by a novel nucleating agent","authors":"Xintu Lin ,&nbsp;Ruijie Jin ,&nbsp;Yidan Ouyang ,&nbsp;Zehong Chen ,&nbsp;Ruilan Xu ,&nbsp;Yincai Wu ,&nbsp;Xin Dai ,&nbsp;Yong Peng ,&nbsp;Yuejun Liu","doi":"10.1016/j.tca.2024.179808","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179808","url":null,"abstract":"<div><p>As a type of renewable and biodegradable polymer, poly(lactic acid) (PLA) has been widely used in various fields. However, its weak crystallization ability deteriorates the properties of the final product. In this work, a novel nucleating agent (MWCNTs@CeO₂), multi-walled carbon nanotubes (MWCNTs) decorated with ceria (CeO₂), was synthesized using the hydrothermal method and subsequently used to manipulate the non-isothermal crystallization kinetics and nucleation behavior of PLA. The results show that MWCNTs@CeO₂ can act as an effective nucleating agent to accelerate the crystallization rate of PLA by reducing the half-crystallization time. In non-isothermal crystallization kinetics, the Avrami equation modified by Jeziorny cannot accurately describe the non-isothermal crystallization behavior of PLA and PLA/MWCNTs@CeO₂ composite films, whereas the Mo method can. Furthermore, it is found that the addition of MWCNTs@CeO₂ does not change the crystal structure of PLA, but increases the nucleation and growth rate of PLA, thereby promoting its crystallization.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179808"},"PeriodicalIF":3.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141596896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat capacities and role of defects in ion transfer of quinuclidinium hexafluorophosphate plastic crystal","authors":"Xue Lan ,&nbsp;Yu Li ,&nbsp;Xianmin Zhang ,&nbsp;Wei Xu ,&nbsp;Hao Chen ,&nbsp;Jiandang Liu ,&nbsp;Hongjun Zhang ,&nbsp;Xiaozheng Lan","doi":"10.1016/j.tca.2024.179804","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179804","url":null,"abstract":"<div><p>To study the phase behavior and role of defects in the ion conduction of a well-investigated plastic crystal electrolyte, we measured the low-temperature heat capacities of quinuclidinium hexafluorophosphate ([HQ]PF₆) plastic crystal and the defects of pure [HQ]PF₆ and its mixtures containing lithium ions and chloride ions. The heat capacities of the pure material show two solid‒solid phase transitions at room temperature and a low temperature. Positron annihilation lifetime spectroscopy (PALS) revealed the phase dependence of the defect size for both the pure material and the mixtures. The defects in these two mixtures expand largely to approximately 2 (with Li⁺) and 2.5 (with Cl⁻) times larger than those in the pure material. The relationships between the ionic conductivity and vacancy volume of the pure material and the mixtures obey the Cohen−Turnbull free volume model, which is also phase dependent. This work help elucidate defect-assisted ion transfer in organic ionic plastic crystals.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179804"},"PeriodicalIF":3.1,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141481576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Liquid crystalline polyurethane/POSS hybrid nanocomposites pyrolysis studies by Py-GC/MS and TG/FTIR techniques","authors":"Artur Bukowczan,&nbsp;Paulina Zając,&nbsp;Krzysztof Pielichowski","doi":"10.1016/j.tca.2024.179803","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179803","url":null,"abstract":"<div><p>The process of pyrolysis of liquid crystalline polyurethane (LCPU) composites with polyhedral oligomeric silsesquioxanes (POSS) has been studied using pyrolysis - gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetry/Fourier transform infrared spectroscopy (TG/FTIR) coupled thermoanalytical techniques. LCPU elastomers modified with POSS molecules with different architectures, bearing aromatic, isobutyl and cycloaliphatic moieties, yield various volatile products of pyrolysis that were collected and characterized. The TG study showed significant differences in the thermal behavior of composites studied, evidencing the influence of the silsesquioxane type on the polyurethane pyrolysis paths. FTIR study of volatile products of thermal decomposition showed the presence of characteristic bands originated from carbonyl, amine, ether, methylene, and unsaturated hydrocarbon linkages. GC/MS investigation confirmed the existence of compounds identified by the IR method. The application of both thermoanalytical methods made it possible to postulate the thermal decomposition routes of PU/POSS hybrids and to point out the main factors responsible for changes in the thermal stability.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"738 ","pages":"Article 179803"},"PeriodicalIF":3.1,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141444463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}