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Thermal transport properties for the isotropic and anisotropic characterization of nanolayers have been a significant gap in the research over the last decade. Multiple studies have been close to determining the thermal conductivity, diffusivity, and boundary resistance between the layers. The methods detailed in this work involve non-contact frequency domain pump-probe thermoreflectance (FDTR) and photothermal radiometry (PTR) methods for the ultraprecise determination of in-plane and cross-plane thermal transport properties. The motivation of one of the works is the advantage of the use of amplitude (TR signal) as one of the input parameters along with the phase for the determination of thermal parameters. In this article, we present a unique strategy for measuring the thermal transport parameters of thin films, including cross-plane thermal diffusivity, in-plane thermal conductivity, and thermal boundary resistance as a comprehensively reviewed article. The results obtained for organic and inorganic thin films are presented. Precise ranges for the thermal conductivity can be across confidence intervals for material measurements between 0.5 and 60 W/m-K for multiple nanolayers. The presented strategy is based on frequency-resolved methods, which, in contrast to time-resolved methods, make it possible to measure volumetric-specific heat. It is worth adding that the presented strategy allows for accurate (the signal in both methods depends on cross-plane thermal conductivity and thermal boundary resistance) and precise measurement. [ABSTRACT FROM AUTHOR]

In this Tutorial, we present an overview of the development of the photopyroelectric (PPE) technique from its beginning in 1984 to the present day. The Tutorial is organized into five sections, which explore both theoretical and experimental aspects of PPE detection as well as some important spectroscopic and calorimetric applications. In the "Introduction" section, we present the fundamental basics of photothermal phenomena and the state-of-the-art of photopyroelectric technique. In the "Theoretical aspects" section, we describe some specific cases of experimental interest, with examples in both back and front detection configurations. Several mathematical expressions for the PPE signal in specific detection modes (combined back–front configurations and PPE–thermography methods) are also deduced. The "Instrumentation and experiment" section contains two subsections. The first describes several examples of setups used for both room temperature and temperature-controlled experiments. The second subsection is dedicated to the configuration of detection cells and to the various sensor/sample assemblies that are currently used in spectroscopic and calorimetric experiments for both liquid and solid samples. The "Applications" section is in fact a collection of experimental results dedicated to the thermal characterization of a wide range of solid and liquid samples. At the end of this section, we present some examples that have been selected to convey that the PPE technique is not only useful in the investigation of optical and thermal properties of a variety of condensed matter samples, but also to study physical and chemical processes such as molecular associations, food adulteration, or phase transitions. In "Concluding remarks," we summarize the advantages of this technique in spectroscopic and calorimetric applications. [ABSTRACT FROM AUTHOR]

This paper delves into the development of biocomposite (BC) packaging material from tapioca starch (TS), flax seed gel (FS), and Siam weed (SW) extract, considering the increased demand for sustainable, eco-friendly packaging materials. The BCs—BC1 (40 mL), BC2 (80 mL), and BC3 (120 mL), prepared by varying the concentration of SW—were subjected to morphological, structure, thermal, and optical characterisations. The BC with a fragmented, agglomerated morphology shows cellulosic peaks in the X-ray diffraction pattern, indicating the C-type crystalline structure in TS. Thermogravimetric analysis confirmed the BC's safe use up to 300 °C, with a minimal 40% weight loss. Differential scanning calorimetry plots identified heat absorption during gelatinisation, with an endothermic peak at 300 °C marking a phase transition. The Fourier transform infrared (FTIR) and UV–visible spectra revealed functional groups that attribute antibacterial potential to the BC. The optical analyses show greater absorption and fewer emissions, resulting in the increased enthalpy responsible for the microbial activities. Antibacterial studies demonstrated BC2's efficacy against Staphylococcus aureus, while the stability against humidity and the minimal weight loss underscored the BC's robust thermal stability. FTIR spectra of post-heating at 80 °C confirmed the structural integrity, positioning the BC as a promising material for eco-friendly packaging solutions. [ABSTRACT FROM AUTHOR]

The work reported in the paper addresses the thermal diffusivity (TD) tuning of the electronic sensor material polyvinylidene fluoride (PVDF). The thermal properties of electronic material were found to influence the device characteristics significantly, demanding novel techniques for TD tuning. The TD value of the carbon sources—hydroxyethyl cellulose (HC), lignin (LG), and camphor soot (CS) and their composites—were measured by the sensitive nondestructive evaluation technique—photothermal beam deflection. When the HC and LG enhanced the TD of PVDF by 237.5% and 27.5%, respectively, CS was found to lower it by 11.25%. The spectroscopic analysis revealed the variation of hydroxyl groups in the samples and suggested its prominence in deciding the TD value. The Fourier transform infrared analysis and beam deflection measurements exhibited a positive correlation between hydroxyl groups and TD, except for the composite PVDF combined with soot. In this case, the amorphous carbon in soot reduced PVDF's TD due to the heat trap mechanism of carbon allotropes. The induced variation of TD of PVDF via carbon source integration is attributed to the closure of pores in PVDF, revealed through the optical microscopic images, thereby suggesting a methodology for enhancing or reducing TD of PVDF. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effects of coating thickness and curing temperature on the properties of a polybutyl methacrylate-siloxane coating deposited on structural steel S355. First, the thermal properties of the sol as a function of temperature were investigated using thermogravimetric analysis coupled with mass spectrometry and differential scanning calorimetry. After coating deposition on structural steel S355 using a dip-coating process, the coating composition and porosity were evaluated using Fourier transform infrared spectroscopy and photothermal beam deflection spectroscopy. In the second part, coating thickness, topography, and corrosion properties were studied as functions of withdrawal rate during deposition. The corrosion properties of variously prepared coatings were evaluated using electrochemical impedance measurements in 3.5 wt.% NaCl and salt spray testing according to the ASTM B117 standard. An elevated curing temperature (at 150 °C) of the polybutyl methacrylate siloxane sol-gel coating impairs greater crosslinking and lower porosity, while the optimal thickness of 4 μm is achieved with the appropriate withdrawal rate to obtain a homogeneous, defect-free surface. Under these optimal conditions, the protection of structural steel against corrosion in a chloride environment lasting for more than 6 months can be achieved. [ABSTRACT FROM AUTHOR]

In this study the adsorption and photodegradation capabilities of modified multi-walled carbon nanotubes (MWCNTs), using tartrazine as a model pollutant, is demonstrated. MWCNT-COOH/Fe3O4 and MWCNT-COOH/Fe3O4/NiO nanocomposites were prepared by precipitation of metal oxides in the presence of MWCNTs. Their properties were examined by X-ray diffraction in powder (XRD), Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy, synchrotron-based Scanning PhotoElectron Microscopy (SPEM), and Brunauer-Emmett-Teller (BET) analysis. It was found that the optimal adsorption conditions were pH 4 for MWCNT-COOH/Fe3O4 and pH 3 for MWCNT-COOH/Fe3O4/NiO, temperature 25 °C, adsorbent dose 1 g L−1, initial concentration of tartrazine 5 mg L−1 for MWCNT-COOH/Fe3O4 and 10 mg L−1 for MWCNT-COOH/Fe3O4/NiO and contact time 5 min for MWCNT-COOH/Fe3O4/NiO and 15 min for MWCNT-COOH/Fe3O4. Moreover, the predominant degradation process was elucidated simultaneously, with and without simulated sunlight irradiation, using thermal lens spectrometry (TLS) and UV–Vis absorption spectrophotometry. The results indicated the prevalence of the photodegradation mechanism over adsorption from the beginning of the degradation process. [ABSTRACT FROM AUTHOR]

BACKGROUND: The use of indigenous selected starters in winemaking is gaining interest due to certain advantages for the sensory quality of the wine. The present work shows the results of a laboratory experiment in which the influence of selected indigenous yeasts on the colour characteristics of Pinot Noir was studied with the use of high hydroxycinnamate decarboxylase activity yeasts. Pichia guilliermondii ZIM624 and Wickerhamomyces anomalus S138 yeasts were used in sequential fermentation with two strains of Saccharomyces cerevisiae, the native ZIM2180 strain and commercial Fermol Premier Cru (FPC). RESULTS: In co‐inoculation fermentations, non‐Saccharomyces yeasts decreased colour intensity (on average by 25.5%). In wines fermented with ZIM624, the concentration of vinylphenolic pyranoanthocyanins increased (average concentration 1.5 mg L−1). However, vitisin concentration was significantly higher in S138 + FPC fermentation (1.3 mg L−1 and an average of 0.9 mg L−1, respectively). Pinot Noir wines fermented with only ZIM2180 and sequential inoculation of ZIM624 + ZIM2180 resulted in significantly higher colour intensity (6.1 ± 0.0 AU and 4.4 ± 0.0 AU, respectively) and lower wine hue parameters compared to other wines. Sensory evaluation also showed that both wines had the highest perceived colour intensity and purple colour suggesting improvement in wine quality parameters. CONCLUSIONS: The results confirmed that selected indigenous starters made out of Saccharomyces and non‐Saccharomyces yeasts can alter Pinot Noir wine colour parameters and improve wine colour properties. Those yeasts properties should be investigated prior to the development of new commercial starters but also be considered in large scale spontaneous fermentations of low colour intensity red wines like Pinot Noir. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Cu/Zr-modified TiO2 photocatalysts were prepared in the form of nanopowders and characterized by photothermal spectrometry, UV–Vis spectrophotometry and X-ray diffraction (XRD) to investigate the effect of Cu/Zr content on their thermo-optical and transport properties. Adding Cu (0.05%) caused a change in the light absorption range limit, which reduced from 3.25 eV for pure TiO2 to 2.85 eV for Cu-modified TiO2. The decrease in energy band gap was accompanied by a 19.5% decrease in the charge carrier lifetime, which is not favorable for photocatalysis. The decrease in charge carrier lifetime can be minimized by additional modification of TiO2 with Zr (1%), which showed insignificant effects on the energy band gap of the investigated materials. Furthermore, modification of TiO2 with Zr affected the material's structure and increased its specific surface area, which improved the adsorption of degraded compounds as well as the absorption of light. Altogether, these effects resulted in higher photocatalytic degradation rate constants of the investigated TiO2-based photocatalyst. It was also found that modification of TiO2 with Cu and/or Zr increases both the material's thermal diffusivity and conductivity due to changes in the band gap and structure of material. Beam deflection spectrometry (BDS) has demonstrated high potential in materials' characterization which stems from its high sensitivity and precision. [ABSTRACT FROM AUTHOR]