IR Irradiation Research Articles

A multifunctional graphene composite coating with switchable wettability

Although many encouraging advances have been made, the further development of the switchable wettability surfaces has been limited by complex preparation process, limited substrate materials, and inconvenient switching wettability methods. Herein, a multifunctional graphene composite coating (MGCC) with switchable wettability was fabricated by simple methods. Attributed to the special properties of nano-TiO2 and graphene, the MGCC can achieve reversible wettability transformation under UV or IR irradiation. The unique wettability and good adhesion make MGCC show potential advantages in many fields. First, spraying MGCC on metal foam or melamine sponge can achieve high-efficiency separation of oil–water layered mixtures (>97.4%) or emulsions (>99.1%). Secondly, due to the light-controlled switchable wettability, MGCC platform can obtain different wettability regions by mask method to manipulate droplets or fluids. Different wetting models (Cassie state, Cassie impregnation wetting state, and Wenzel state) could be realized on the same MGCC surface. Thirdly, MGCC can significantly improve the corrosion resistance of metal surface, providing a new solution for corrosion protection. More specifically, the corrosion inhibition efficiency was 99.996%. Finally, MGCC has good anti-icing and active deicing abilities, which are attributed to the superhydrophobicity and excellent photothermal properties of graphene. In particular, ice adhesion strength (IAS) of MGCC surface was only 117 ± 15 kPa, and the ice shear strength (ISS) was only 183 ± 18 kPa. This study provides a new idea for designing a simple, multifunctional, and switchable wettability coating, which is expected to promote the large-scale preparation and application of functional integrated smart surface.

Solvent‐free Reactions for the Synthesis of Indolenine‐based Squaraines and Croconaines: Comparison of Thermal Heating, Mechanochemical Milling, and IR Irradiation

Squaraines and croconaines are organic dyes characterized by intense absorption in the visible or near-infrared spectral regions with applications ranging from biology to material sciences. They are commonly synthesized by condensation reactions of oxocarbonic acids (squaric or croconic acid, respectively) with electron-rich aromatic compounds in high-boiling organic solvents. Here, a simple, cost-effective, and environmentally benign process was developed for the synthesis of indolenine-based squaraines and croconaines under solvent-free conditions. Protocols based on conventional thermal heating, mechanochemical milling, and IR-light activation were compared.

Nonstoichiometric perovskite CaMnO3-δ nanomaterial for photocatalytic reduction of CO2

Nanostructured perovskite oxides have emerged as a class of high-performance photocatalytic materials. In this study, the nonstoichiometric perovskite CaMnO3-δ nanomaterial is reported as a potential photocatalyst under IR and visible irradiation. The as-prepared sample was characterized by Brunauer−Emmett−Teller (BET) method and the diffuse reflectance spectroscopy (DRS). The CO2 photoreduction and methanol yield over CaMnO3-δ under both infrared and visible light irradiation as a function of irradiation time and photocatalyst concentration were investigated by chemical titration and the gas chromatographic analysis (GC-FID). The first and second harmonics of Nd:YAG laser with wavelengths of 1064 and 532 nm were used as the excitation source. After 20 min of 532 nm irradiation, the methanol yield for catalyst concentration of 0.6 g/lit exhibited the highest value (1138 μmol/g), while the methanol started to degrade with the increase of irradiation time. We have shown that under visible and IR irradiations, the electron photoexcitation from the hybridized O-2p and Mn-3d eg↑1 valance band to the Mn-3d eg↑2 conduction band provided CO2•δ− anion radicals which are required for CO2 photoreduction to methanol. This study makes the nonstoichiometric CaMnO3−δ a promising active catalytic material for CO2 photoreduction to methanol under IR and visible light irradiation.

Fabrication of a Dual Stimuli-Responsive Assorted Film Comprising Magnetic- and Gold-Nanoparticles with a Self-Assembly Protein of α-Synuclein.

Development of sensing elements for controllable soft materials is crucial to improve their responsiveness toward remotely provided external stimuli. Magnetic nanoparticles (MNPs) and gold nanoparticles (AuNPs) have been coassembled into a flexible free-floating 2D film to produce a shape deformable mobile structure in the presence of magnetic field and light irradiation by employing a self-assembly protein of α-synuclein (αS). αS was demonstrated to be essential for the preparation of a multisensory system because the intrinsically disordered protein led to a complete dispersion of MNPs to an average size of 10 nm in aqueous solution, pH-dependent closely packed single layer adsorption of αS-MNPs, and α-helix-mediated free-floating MNP monolayer film formation upon dissolving the underlying polycarbonate substrate with chloroform. As AuNPs were incorporated into the assorted hybrid film in the presence of MNPs, however, the β-sheet component became prominent. By placing the assorted film between a spin-coated thin layer of thermoresponsive P(AAc-co-NIPAAm) hydrogel comprising acrylic acid and N-isopropylacrylamide and a passive layer of silicone elastomer, the resulting triply structure exhibited not only magnet-induced locomotion but also shape deformation due to asymmetric contraction of the sandwiching two layers caused by the heat generated by AuNPs upon near IR irradiation. In fact, two adjoining planar layers of another triply structure were shown to form a three-dimensional lotus flower with the light. This multisensory system is suggested to be further functionalized by modifying the αS molecules and incorporating additional nanoparticles to react to diverse stimuli, which would make the system be utilized in the areas of not only soft robotics but also foldable electronics, high-performance sensors/actuators, and medical/wearable applications.

Gallato Zirconium (IV) Phtalocyanine Complex Conjugated with SiO2 Nanocarrier as a Photoactive Drug for Photodynamic Therapy of Atheromatic Plaque

A new conjugate of gallato zirconium (IV) phthalocyanine complexes (PcZrGallate) has been obtained from alkilamino-modified SiO2 nanocarriers (SiO2-(CH2)3-NH2NPs), which may potentially be used in photodynamic therapy of atherosclerosis. Its structure and morphology have been investigated. The photochemical properties of the composite material has been characterized. in saline environments when exposed to different light sources Reactive oxygen species (ROS) generation in DMSO suspension under near IR irradiation was evaluated. The PcZrGallate-SiO2 conjugate has been found to induce a cytotoxic effect on macrophages after IR irradiation, which did not correspond to ROS production. It was found that SiO2 as a carrier helps the photosensitizer to enter into the macrophages, a type of cells that play a key role in the development of atheroma. These properties of the novel conjugate may make it useful in the photodynamic therapy of coronary artery disease.

ІНФОРМАЦІЙНІ ТЕХНОЛОГІЇ ДЛЯ СИСТЕМ ПІДТРИМКИ ПРИЙНЯТТЯ РІШЕНЬ З ІНФРАЧЕРВОНОГО СУШІННЯ ЗЕРНА

Rapid growth of information technologies causes the changes in many production processes. The effectiveness of elec-trotechnical means of infrared radiation is due to the application of new, scientifically grounded methods and means of energy supply control using controllers and personal computers, new information technologies and systems.Therefore, there is a need for further mathematical models development as well as information technology used in deci-sion support systems on infrared grain drying from elevators and granaries.Research and publication analysis on information support questions of grain drying based on infrared radiation technol-ogy has shown that the issues of information support systems are currently underexplored in scientific literature.The goal of this research is mathematical modeling of the IR grain drying process and information support development of the drying process, taking into account the obtained mathematical model.The improved model of the infrared drying process for grain crops is proposed, which, in contrast to the existing ones, is focused on application in decision support systems when organizing the drying process. The results of the experiments proved that infrared radiation use contributes to the intensification of the grain drying process due to a significant heat flux rate increasing on the material’s irradiated surface and the of infrared rays’ penetration into material. It has been proved that modern information technology, rational schemes and operating parameters of infrared grain drying processes utilization will reduce dehydration time with "gentle" drying modes to ensure the required quality parameters of the product.In this work it was first proposed to abandon probabilistic models of grain flow behavior under IR irradiation. A new mathematical model has been proposed based on information about the characteristics of the heat flow, dehydration and grain mass’ condition. This will significantly improve the IR grain drying process and get a higher quality product

Effect of the Loading of Metal Salts on the Formation of Fe–Co Solid Solution Nanoparticles in the IR-Pyrolyzed Chitosan Matrix

In this study, metal-carbon nanocomposites have been synthesized via the method of simultaneous formation of bimetallic Fe–Co nanoparticles and carbon support based on pyrolyzed chitosan under the IR irradiation. The XRD structural characteristics as well as morphology and dispersity of Fe–Co nanoparticles depending on the loading of metals in the nanocomposites have been studied. It has been shown that the increase in the metal salts loading in the precursor leads to the formation of metal nanoparticles of larger size and more homogeneous composition of the Fe–Co solid solution. Detailed analysis of the XRD peaks of the obtained Fe–Co phase has allowed to distinguish them into several phases of a solid solution based on body-centered cubic and face-centered cubic lattices.

Effect of IR irradiation on the various properties of chemically prepared zinc sulphide thin films

Zinc sulphide thin films have been deposited on glass substrate using simple low cost chemical bath deposition method at 80°C for 2 hours. One of the samples is post irradiated with infrared radiation for one hour. Structural, optical and morphological studies were done for both samples and the results were compared. XRD pattern of the IR irradiated sample shows enhanced crystallinity. Optical band gap was found to be 3.31eV for pure ZnS and 3.93 eV for the IR irradiated ZnS thin film. The films prepared by using this facile method are suitable for optoelectronic applications.

Effect of post irradiation of IR light on the structural, morphological and optical properties of ZnO thin film grown by CBD method

Abstract Zinc oxide thin film was synthesized on commercial microscopic glass slide by using chemical bath deposition (CBD) technique and the prepared film was post irradiated with IR light. We compared the structural, optical and morphological properties of as deposited and IR irradiated ZnO thin films. The XRD pattern of pure and IR irradiated ZnO confirms that both the films were polycrystalline in nature. The optical band gap was found to be 3.5 eV and 3.04 eV for as deposited and IR irradiated samples. The SEM studies reveals that IR irradiation effects ZnO thin films morphology. The films prepared by this method can be used in optoelectronic applications.

Assessment of the Influence of Pyrogenic Factors on the Biological Properties of Chernozems

Changes in the biological properties of chernozems caused by several pyrogenic agents have been studied in simulation experiments with the low-temperature plasma, infrared irradiation, straw burning, and fume of burning products. It has been shown that the pyrogenic effect has a complex nature, so that worsening of biological parameters depends on temperature, duration of fire episode, intensity of fume, ash impact, and soil moisture. Such integrated effect induced a decrease in microbial biomass by 39%, population of nitrogen-fixating bacteria by 29% versus the control values. The inhibition of dehydrogenase and catalase (oxidoreductase class) was 44–53%; the activity of hydrolase (phosphatase and invertase) was lower (by 16–18%). A maximal effect was recorded for the uppermost soil layer (0–1 сm) as compared to the lower 4–5 сm layer. Microbiological indices went down by 52–56% after placing the sample in the flame of a gas burner for 3 minutes, while soil enzyme activity decreased by 25–26%. For the latter, the duration of flame effect was of special importance; the correlation coefficient for dehydrogenase activity was –0.81; for invertase activity, –0.86; for catalase activity, –0.78; and for phosphatase activity, –0.85 (р < 0.01). Increasing IR irradiation also resulted in growing inhibition of biological indices. Even a minimal impact of fume of straw burning products (3 minutes at temperature 52°С) reliably decreased soil microbiological and biochemical parameters (by 4–19%, р < 0.05). Higher level of impact suppresses the biological activity by 20–30%.

Animal heat activated cancer therapy by a traditional catalyst TiO2-Pd/graphene composites

Cancer therapy is one of the most important challenges in clinical medicine. So far different methods have been developed for cancer therapy, such as radiation therapy, surgery, chemotherapy and photodynamic therapy. Here we propose a new concept for cancer therapy, i.e., killing the cancer cells simply via reactive oxygen species (ROS) generated by TiO2-Pd/graphene composites. Activated by animal heat of 37 °C, the electrons in the valence band can be excited to the conduction band of TiO2 via the energy levels of Pd species and graphene, generating ROS without light irradiation or electric excitation. The tumors in BALB/c mice are successfully regressed at animal heat without any other external conditions, such as radiation, UV, visible and IR irradiation. Our results suggest that the design of animal heat activated cancer therapy is a feasible concept for practical applications of cancer treatments.

Heat Transfer in a Water Drop Containing a Dye and Nanoparticles under Double Laser Irradiation

Heat transfer in a water drop containing eosine and ablation silver nanoparticles induced by stationary visible laser irradiation, λ = 532 nm, and pulsed IR laser irradiation, λ = 10.6 μm (VIS–IR double laser irradiation), has been studied in the temperature interval of 0.2–50°C. It has been found that the vibratory system of triplet states in a dye molecule heats up after VIS–IR laser irradiation, causing thermoluminescence. The thermoluminescence decay kinetics indicates a new distribution of electron vibration modes in the fluorescence spectrum of dye molecules. If the drop with nanoparticles is small (d < 1 mm), pulsed IR irradiation (τ = 50 ms) gives rise to a thermal front causing thermoluminescence, which travels in the drop with a velocity of 0.85 cm/s. Heat transfer in the drop during the formation of a thermal wave has been simulated.

Electrically Stimulated Band Alignment Transit in Black Phosphorus/β-Ga2O3 Heterostructure Dual-band Photodetector

In recent decades, dual-band photodetectors have received widespread attention due to better target identification, which are considered as the development trend of next generation photodetectors. However, the traditional dual-band photodetectors based on heteroepitaxial growth, superlattice and multiple quantum well structures are limited by complex fabrication process and low integration. Herein, we report a UV/IR dual-band photodetector by integrating ultra-wide gap β-Ga2O3 and narrow-gap black phosphorous(BP) nanoflakes. A vertical van der Waals (vdW) heterostructure is formed between BP and β-Ga2O3 by mechanically exfoliated method integrated without the requirement of lattice match. The heterostructure devices show excellent rectification characteristics with high rectifying ratio of ca. 106 and low reverse current around pA. Moreover, the device displays obvious photoresponse under UV and IR irradiations with responsivities of 0.87 and 2.15 mA/W, respectively. We also explore the band alignment transit within the heterostructure photodetector at different bias voltages. This work paves the way for fabricating novel dual-band photodetectors by utilizing 2D materials.

Autotrophic sulfide removal by mixed culture purple phototrophic bacteria

Current H2S treatment methods for sour gases require considerable amounts of chemicals and energy, or in case of biological treatment, unwanted diluents such as oxygen or nitrogen may be introduced. In order to reduce those requirements, the viability of an anaerobic biological H2S removal process using purple phototrophic bacteria (PPB) was investigated in this study. PPB can use sunlight, and centrate as nutrient source, thus potentially reducing energy and chemical requirements. An added benefit is the production of biomass with potential uses, such as single cell protein. An inoculum of PPB enriched from domestic wastewater was grown photoautotrophically with sulfide as the electron donor and inorganic carbon in a mixed culture. Additionally, synthetic medium and centrate as well as high (56 ± 11 Wm-2) and low (27 ± 3 Wm-2) IR irradiation were trialled. Finally, a process model was developed to study biomass specific removal rates and yield. The results showed that a mixed culture of PPB removed sulfide completely in synthetic media (121 ± 9 mg-S.L−1) at a maximum rate of 1.79 ± 0.16 mg-S(Lh)−1 (low irradiance) and 2.9 mg-S(Lh)−1 (high irradiance). The pH increased in both experiments from about 8.5 to 9. Sulfide removal rates using centrate and low irradiance were similar. However Fe and Mn were found to be limiting growth and sulfide removal. In all experiments, Chromatiaceae (purple sulfur bacteria) were most abundant at the end of the experiment, while at the start purple non-sulfur bacteria were most abundant (from the inoculum). Process modelling and experimental work identified the sulfide oxidation to be a multi-step process with accumulation of intermediates. Specific rates were directly dependent on light input, doubling at high irradiance. Sulfide oxidation was estimated at 0.100 ± 0.014 h−1 (0.085 ± 0.012 g-S(g-VS.h)−1) at low irradiance, and the biomass yield at 0.86 ± 0.05 mg-COD.mg-COD−1. This process model enables the virtual evaluation of autotrophic sulfide removal by PPB in a continuous scaled-up process. Overall, the photoautotrophic removal of sulfide seems to be a viable option, especially because of the possibility of using sunlight as an energy source and centrate as a nutrient source.

Improvement of ionization yield in sputtered neutral mass spectrometry using pulsed infrared and ultraviolet lasers

A new laser ionization method for sputtered neutral mass spectrometry (SNMS), which the authors call “dual-laser SNMS,” was developed to increase the ionization probability and improve sensitivity. In this technique, pulsed IR and UV lasers irradiated sputtered atoms simultaneously, while the additional UV laser pulse enhanced the ionization process. The useful yields of the target elements increased by 10%–20% compared to using the IR irradiation alone, and the yield increased with increasing UV power. In addition, there was little correlation between the ionization potential and the ratio of the ionization enhancement. Therefore, dual-laser SNMS was effective for the analysis of elements with higher ionization potential.

Modeling the inactivation of Bacillus cereus by infrared radiation in paprika powder (Capsicum annuum)

AbstractInfrared (IR) irradiation, a novel technology for modeling of decontamination of Bacillus cereus in paprika powder was evaluated and the effect on temperature profiles and total phenolic content was determined. The highest reduction in B. cereus count (2.3 log CFU/g) was achieved after a holding time of 1 min at 200 W IR power and 5 cm distance. The rapid rise in temperature was observed in surface paprika powder and the highest temperature at 200 W IR power and 5 cm distance reaching to 127.8°C. An increase in IR power and a decrease in sample distance of the IR lamp caused a significant decrease in the total phenolic content. The Double Weibull model closely predicted the inactivation of B. cereus in paprika powder by IR irradiation.

Photocatalytic removal of airborne indoor pollutants by IR illuminated silver coated TiO2 catalyst: Advantage of one-dimensional TiO2 nanostructures in IR active photocatalysis

The development of IR sensitive photocatalysts is indispensable for the abatement of indoor pollutants as most of the photocatalysts mainly absorb radiation in the UV region and weakly in the visible region and not responding to indoor conditions. On the other hand, IR photons initiated photochemical reaction needs a highly efficient excited charge separation step as it is a multi-excitation process. In order to enhance the charge separation process in multi-step excitation photocatalytic systems, in this investigation the photocatalytic activities of silver coated 1-D TiO2 nanotubes were employed and the photocatalytic activity of 1-D TiO2nanotubes was compared with the photocatalytic activity of TiO2 nanoparticles. A superior photocatalytic activity was noted with the silver coated 1-D TiO2 nanotubes under IR irradiations than that of silver coated TiO2 nanoparticles. The impedance measurements were conducted by electrochemical impedance spectroscopy to differentiate the transport resistances, electron-hole recombination and electron lifetime of the silver coated 1-D TiO2nanotubes and nanoparticles. The possibility of the use of silver coated 1-D TiO2 nanotubes for the degradation of common airborne pollutants with near IR photons (similar to indoor conditions) was successfully demonstrated.

Efficient UV-vis-IR photothermocatalytic selective ethanol oxidation on MnOx/TiO2 nanocomposites significantly enhanced by a novel photoactivation

MnOx/TiO2 nanocomposites exhibit good catalytic activity and excellent durability for photothermocatalytic selective ethanol oxidation under UV-vis-IR and IR irradiation. A novel photoactivation is found to significantly enhance catalytic activity due to activation energy being reduced upon irradiation.

Solar Heat‐Enhanced Energy Conversion in Devices Based on Photosynthetic Membranes and PEDOT:PSS‐Nanocellulose Electrodes

AbstractEnergy harvesting from photosynthetic membranes, proteins, or bacteria through bio‐photovoltaic or bio‐electrochemical approaches has been proposed as a new route to clean energy. A major shortcoming of these and solar cell technologies is the underutilization of solar irradiation wavelengths in the IR region, especially those in the far IR region. Here, a biohybrid energy‐harvesting device is demonstrated that exploits IR radiation, via convection and thermoelectric effects, to improve the resulting energy conversion performance. A composite of nanocellulose and the conducting polymer system poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is used as the anode in biohybrid cells that includes thylakoid membranes (TMs) and redox mediators (RMs) in solution. By irradiating the conducting polymer electrode by an IR light‐emitting diode, a sixfold enhancement in the harvested bio‐photovoltaic power is achieved, without compromising stability of operation. Investigation of the output currents reveals that IR irradiation generates convective heat transfer in the electrolyte bulk, which enhances the redox reactions of RMs at the anode by suppressing diffusion limitations. In addition, a fast‐transient thermoelectric component, originating from the PEDOT:PSS‐nanocellulose‐electrolyte interphase, further increases the bio‐photocurrent. These results pave the way for the development of energy‐harvesting biohybrids that make use of heat, via IR absorption, to enhance energy conversion efficiency.

Hydrogen-atom tunneling reactions with methyl formate in solid para-hydrogen: Infrared spectra of the methoxy carbonyl [•C(O)OCH3] and formyloxy methyl [HC(O)OCH2•] radicals.

We investigated the reaction of methyl formate, HC(O)OCH3, with hydrogen atoms in solid para-hydrogen (p-H2) at 1.74 and 3.3 K with infrared absorption spectroscopy. Hydrogen atoms were produced either upon direct photolysis of HC(O)OCH3 at 193 nm or upon irradiation of Cl2, codeposited with HC(O)OCH3 in p-H2, with light at 365 nm to produce Cl atoms that react with the p-H2 host via the reaction Cl + H2 (ν = 1) → HCl + H induced by subsequent IR irradiation of the p-H2 matrix. We assigned lines at 1785.2, 1170.6, 1104.6, and 879.4/880.5 cm-1 and five additional weak lines to the methoxy carbonyl radical, •C(O)OCH3, and three weak lines at 1751.3, 1152.9, and 994.4/996.8 cm-1 to the formyloxy methyl radical, HC(O)OCH2•, according to the consideration of possible reactions, correlated variations in intensities after each experimental step, and comparison of observed vibrational wavenumbers and IR intensities with values predicted with the B3LYP/aug-cc-pVTZ method. Unlike most reported H-atom diffusion tunneling reactions, the reaction H + HC(O)OCH3 in solid p-H2 at 3.3 K was found to diminish rapidly after IR irradiation, but, similar to reactions of H + N2O and H + HC(O)OH, this reaction was reinitiated when the matrix temperature was decreased from 4.0 K to 1.5 K. We confirmed that the method used to generate the mobile H atoms does not affect the subsequent chemistry. A possible reaction mechanism and the role of this reaction in dark interstellar clouds are discussed.