Vacuum Evaporation Research Articles

Impact of the thickness of phthalocyanine films and its metal complexes on optical and electrical properties

The paper presents the results of a study of the structural, optical and electrophysical characteristics of phthalocyanine films and its metal complexes with different thicknesses. Films of phthalocyanine and its metal complexes were obtained on the conductive surface of the FTO by thermal evaporation in vacuum. It is shown that the observed broadening of the B and Q bands and the hypsochromic shift of the maxima in the absorption spectra are associated with the central atom. With a decrease in the thickness of MPc films, there is a decrease in the value of the half-width of the absorption spectra. The effect of the thickness of phthalocyanine films on the efficiency of generation and transport of charge carriers in the FTO/MPc/Al cell was studied. It is shown that the VAC increases almost 2.5 times compared to a photocell based on a metal-free phthalocyanine. From the obtained impedance measurement data, it was found that the electrophysical parameters of phthalocyanines depend on the values of optical density, broadening of absorption bands in the short-wave and visible spectral regions, which is consistent with the data of the volt-ampere characteristic.

Fabrication of Ag/PP terahertz hollow waveguide by vacuum evaporation method and transmission performance investigations

This work proposed a vacuum evaporation method in preparing an Ag/polypropylene (PP) terahertz (THz) hollow waveguide (HWG). Rray model and COMSOL were used to optimize the geometric structure parameters of the HWG. Accordingly, a 5 mm bore PP tube with a wall thickness of 360 μm was selected as the structural and dielectric tube, and a silver reflective layer was deposited onto the outer surface of the PP tube using vacuum evaporation process. The as-deposited Ag layer consists of small Ag particles (about 100 nm) which contribut to form a more uniform and smoother metal reflective layer than that could be prepared via the wet chemical method. Terahertz time-domain spectroscopy (THz-TDS) analysis confirms that the Ag/PP THz HWG exhibits a low-loss window centered at the frequency of 0.1 or 0.3 THz. The HWG sample shows low transmission losses of 2.26 dB/m at 0.1 THz and 1.23 dB/m at 0.3 THz, respectively. The THz waves could be stably transmitted through the as-fabricated Ag/PP waveguide at low (−78.5 °C) and high (65 °C) temperatures. This research opens a simple and environmentally friendly avenue for the fabrication of low-loss metal/dielectric THz HWG. It is helpful for promoting the applications of THz HWG in future THz imaging, sensing and 6G communication.

Fabrication and characterization of thin [formula omitted]Sn films for heavy-ion nuclear reaction measurements

The fabrication of thin isotopically enriched 120,124Sn targets have been presented. The thin film targets prepared have been used in nuclear physics experiments to apprehend the heavy-ion fusion and multi-nucleon transfer reaction dynamics around the Coulomb barrier. Vacuum evaporation viz. resistive heating technique has been used for the fabrication of the targets with varying areal densities in the range of 50–250 μg/cm2 backed with a carbon layer of ≈20μg/cm2 using a nominal amount of 30 mg isotopically enriched material. The fabricated targets have been characterized using multiple advanced techniques viz. Energy Dispersive X-ray Spectroscopy (EDS), Scanning Electron Microscopy (SEM), and X-ray Diffractometry (XRD). The thickness of the targets has been measured using Rutherford Back-scattering Spectrometry (RBS). The isotopic contamination levels have been ascertained with an in-beam experiment using Heavy Ion Reaction Analyzer at IUAC, New Delhi.

ALUMINUM OXIDE IN VACUUM CONDENSATES BASED ON COPPER

Strengthening of copper and copper alloys with aluminum oxide particles is an important technological technique. Composite materials based on copper strengthened with aluminum oxide particles have a significant operating temperature range and better mechanical properties at elevated temperatures than age-hardening alloys. However, at moderate operating temperatures, the use of age-hardening alloys remains more economically justified. The main direction in the development of composites strengthened with oxide particles is the dispersion of the strengthening phase to sizes of several or one nanometer, which will bring their mechanical properties to the level of age-hardening alloys. However, dispersion leads to a significant increase not only in strength, but also in electrical resistance. The adverse effect on the electrical conductivity of dispersed particles will decrease with a decrease in the volume fraction of oxide, bringing the electrical conductivity closer to the level of copper. Based on an analysis of the materials of scientific research devoted to the production of dispersion-strengthened Cu–Al2O3 composites, it was concluded that the most significant progress in the dispersion of oxide particles with uniform distribution in the copper matrix of the composite was achieved using the method of electron beam evaporation and simultaneous deposition (condensation) of vapors of components in vacuum (EB–PVD). Structural studies of the morphology of aluminum oxide particles in dispersion-strengthened copper composites were carried out using methods such as: X-ray fluorescence analysis, transmission electron microscopy, and energy-dispersive X-ray spectroscopy (EDS). The average size of aluminum oxide particles in the studied dispersion-strengthened composites was in the range from 1.8 to 3 nm. In the work, the dependence of the specific electrical resistance of composites (ρ) on the oxide content was investigated. It was found that a decrease in the size of oxide particles leads to an increase in the electrical resistance of the dispersion-strengthened composite. The studies of the method of electron beam evaporation and subsequent condensation in vacuum, presented in the work, confirm the possibility of further dispersion of aluminum oxide particles with simultaneous narrowing of the distribution histogram. This opens up prospects for further improvement of vacuum dispersion-strengthened copper-based composites.

The value of charge of Fe single to multiple atoms doped in Ge: Combined experimental and density functional theory study

With the aim to find out the value of an electronic charge that the Fe atoms acquire when they are doped in Ge bulk, a set of experimental and density functional theory (DFT) studies have been carried out of the model systems consisting of intermixed Fe–Ge films. Such films were prepared by electron and thermal evaporation in ultra-high vacuum (UHV) on the surface of Mo(110) substrate by initial formation of the Ge film of a mean thickness of 7.5 nm, onto which the Fe films were subsequently deposited, maintaining certain Fe to Ge concentration ratio, namely, 0.2, 0.4, 0.7 and 1.0. Annealing of such double Fe–Ge films results in notable interdiffusion of the components with quite uniform distribution of the elements throughout the intermixed layer. The details of formation of such layers were in-situ controlled by Auger electron spectroscopy (AES), low-energy ion scattering spectroscopy (LEIS), low-energy electron diffraction (LEED) and work function measurements, in combination with Ar ion depth profiling. By analyzing the Fe Auger LMM-triplet, the absolute values of the charge that Fe atoms acquire when doped in Ge, were estimated for four different Fe–Ge intermixed layers with above-mentioned different Fe to Ge concentration ratio. The corresponding plot of the charge versus Fe to Ge concentration allows to estimate the charge of a single doped Fe atom, which equals to +0.34e (electron charge units) and gradually decreases to 0.07e for high Fe concentration. To verify the experimental values of the Fe charge the calculations were done by periodic DFT as implemented in full-potential FHI-aims code. Among the used algorithms of Mulliken, Hirshfeld, and Bader's atoms-in-molecules, the latter gives good correlation between charges of Fe dopant and its concentration.

An Artificial Olfactory System Based on a Memristor Can Simulate Organ Injury and Functions in Air Purification.

Artificial olfactory systems are receiving increasing attention because of their potential applications in humanoid robots, artificial noses, and the next generation of human-computer interactions. However, simulating the human olfactory system, which recognizes, remembers, and automatically takes protective measures against gases, remains a challenge. In this paper, a WO3-TiO2@Ag NPs (silver nanoparticle) gas sensor was prepared by the sol-gel method, and an Al/pectin:AgNP/ITO memristor was prepared by spin coating and vacuum evaporation. The gas sensor has been combined with the memristor to simulate physical damage to humans in a dangerous gas environment for a long time, and an artificial olfactory system is constructed by field-programmable gate array external control. The WO3-TiO2@Ag NPs gas sensor can sense and identify ethanol vapor through changes in resistance, and the signal transmitted to the pectin-based memristor can switch the resistance state of the memristor to store gas information. Furthermore, the activation of the memristor can also trigger rotation of the fan to purify the gas and reduce damage caused by excessive exposure to dangerous gases. This artificial olfactory system provides a promising strategy for the development of artificial intelligence and human-computer interaction systems.

Acaricidal activity of methanolic extract of leaves of Cleistanthuscollinus(Roxb.) Benth. Ex Hook.f

Ticks are parasitic haematophagus arthropods playing a major role in disease transmission among human and animals. Effective tick control is mainly accomplished through widespread use of chemical acaricides, which have a negative impact on environment, humans, and animals due to their toxicity and indiscriminate use leads to resistance developement. So, there arise an essentiality for development of safer, eco-friendly methods for control of acarine parasites. The present study was conducted to identify phytochemicals in methanolic extract of leaves of Cleistanthus collinus. and its acaricidal activity against Haemophysalis bispinosa. Leaves of C. collinus were harvested at the College of Veterinary and Animal Sciences Mannuthy campus in Thrissur, Kerala, India. They were shade-dried, ground into a powder, and extracted using methanol. A rotary vacuum evaporator was used to concentrate extract, and FTIR, GCMS, and qualitative phytochemical screening were carried out. Acaricidal activity was determined by adult immersion assay by accounting for various entomological parameters such as per cent adult mortality, index of egg laying and percent inhibition of fecundity using various concentrations of extract. Phytochemical analysis detected presence of steroids, alkaloids, glycosoides, flavonoids, terpenoids, in methanolic extract of C.collinus leaves. GC–MS analysis confided presence of Dianhydromannitol,Diethyl phthalate, Cyclooctasiloxane, Benzophenone, Dodecanoic acid, Tetradecanoicacid, Hexadecenoic acid, among many compounds. FTIR analysis ascertained presence of various functional groups like aldehydes, sulfoxides, phenol, vinyl ether and aliphatic ketones. There was cent per cent mortality of ticks in all doses tested. Index of egg laying was found to be zero and maximum inhibition of fecundity was observed in higher concentrations. IC50 found to be 30.84 mg/mL. From results, it was clear that methanolic extract of leaves of C.collinus induced very early adult tick mortality. It was apparent that methanolic extract of C.collinus leaves flaunted potent acaricidal activity against H. bispinosa and can be used to develop a potent ectoparasiticide.

Impact of Production Methods and Storage Time on the Bioactive Compounds and Antioxidant Activity of Confitures Made from Blue Honeysuckle Berry (Lonicera caerulea L.)

The blue honeysuckle berry is a fruit known as a rich source of many bioactive substances with proven health-promoting effects. Due to its sour taste with a noticeable hint of bitterness, fruits of this plant are rarely consumed and the consumer prefers the processed form. The purpose of this study was to evaluate the effect of the cooking method on the biological quality of honeysuckle berry confiture. The selected recipe was used to make confiture in a vacuum evaporator using lowered pressure and in a thermomix vessel under atmospheric pressure. Then, the content of the chosen compounds and antioxidant activity of the two types of confitures were compared. The confitures were analyzed right after production and through 180 days of refrigerated storage. The pH, TA and TSS parameters remained unchanged regardless of the production process and storage time. Ascorbic acid, polyphenol and anthocyanin concentrations were greater in the confiture from vacuum cooking. Also, the same confiture showed a lower rate of degradation of bioactive substances during storage. The antioxidant activity of the two types of confiture was significantly different shortly after production, but equal at the end of 180-day storage. HMF content was four times higher in confitures cooked under atmospheric pressure than under vacuum. The confiture made from the honeysuckle berry was very rich in bioactive compounds, especially polyphenols. Vacuum cooking proved to be the best method for confiture production as a result of lower temperatures used and less aeration of the mass.

DEVELOPMENT OF COMPOSITIONS AND TECHNOLOGY OF GELS CONTAINING PHYTOEXTRACTS

Relevance. Today, interest in the use of natural medicinal substances, medicinal products created on their basis and corresponding dosage forms continues to develop. This interest is associated with the unique properties of various phytocompositions, as well as with the intensive development of such classical sciences as biology, chemistry, and pharmacology. An urgent task is the development and introduction into production of original do-mestic dosage forms for external use, created on the basis of medicinal plant raw materials, which will solve the issues of successful pharmacother-apy for a number of diseases. The purpose of our research is to develop optimal compositions of gels based on Ginkgo biloba leaves and Rhodiola rosea rhizomes with roots of thick extracts, their biopharmaceutical studies in vitro for subsequent more in-depth pharmacotechnological studies. Material and methods. The object of our research is soft dosage forms developed on the basis of thick extracts of Ginkgo biloba leaves and Rho-diola rosea rhizomes with roots. Thick extracts were obtained by condensation in a rotary vacuum evaporator), into which the extracts and an alcohol-water-glycerin mixture 1:6:3 were placed. The ratio of thick extract and solvent mixture was 1:1. Mixing was carried out with a stirrer rotating no more than 30 rpm at room temperature until the mass was completely homogenized. The release of biologically active substances was studied by direct dif-fusion into agar and gelatin gels and by equilibrium dialysis through a semipermeable membrane. Results. Studies have shown that the most complete and rapid release of the active complex of the thick extract of Rhodiola rosea occurs from the Na-CMC base (TU 9199-001-07508109-2004). The highest degree of release of the active complex of the thick extract of Ginkgo biloba is observed from the chitosan base (TU 9289-067-00472124-03 Bioprogress LLC). Conclusions. In vitro biopharmaceutical studies were carried out to determine the level of release of the studied active substances of thick extracts of Rhodiola rosea rhizomes with roots and Ginkgo biloba leaves from various gel compositions, allowing to select the optimal composition of the dos-age form.

Surface enthalpy recovery/relaxation of organic films determined by Mg deposition property

Estimating the surface glass transition temperature (T g) of materials is important for making organic devices by vacuum evaporation because the surface T g affects the interface of layered devices and their performance. The enthalpy state of organic films is related to T g. Bulk T g is ordinarily measured by differential scanning calorimetry (DSC), although there is no established method for measuring the surface T g. The Mg deposition property reflects the surface T g; no Mg deposition denotes a low surface T g. In this study, we investigated how annealing affects the bulk and surface T g of N,N′-Bis-(1-naphthalenyl)-N,N′-bis-phenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) using DSC and the Mg deposition properties. For bulk NPB, enthalpy relaxation occurred after annealing at a temperature below T g. On the other hand, for vacuum-deposited NPB film, the enthalpy was in a relaxed state just after preparation, although the surface’s enthalpy recovered by annealing at same condition, as identified by the Mg deposition property.

Molecular And Solid‐State Structure Of Oxovanadium(IV) Etioporphyrin‐III

AbstractOxovanadium(IV) etioporphyrin‐III, VO‐EtioP‐III is an important member of the petroporphyrin family. It can be isolated from crude oil or synthesized de novo from the dipyrromethene precursors, the latter being the approach we used in our research. The molecular structure of VO‐EtioP‐III was for the first time characterized by single‐crystal X‐ray diffraction. Both terminal alkyls and the axial oxygen atom protrude in the same direction relative to the molecular plane, while rear side of the molecule remains almost flat. This results in a peculiar centrosymmetric packing (space group P21/c, monoclinic system with four molecules per unit cell), in which back‐to‐back oriented molecules form the parallel‐plane dimers. The powder X‐ray diffraction data indicate that the VO‐EtioP‐III films deposited by vacuum evaporation retain a very strong texture, with all molecules standing vertically on the substrate surface. The absorption spectra of films differ from the solution spectra by a large redshift of the Soret‐ and Q‐ band (~30 nm) with hypo‐ and hyperchromic effects, respectively. The former band strongly broadens due to multiple splitting to within 350–520 nm, which is followed by a change of the color from purple (in diluted solutions) to brawn (in films or crystals).

Determination of Tetracycline Antibiotics in Milk by Solid-Phase Extraction Using a Coordination Polymer Based on Cobalt Trimesinate as a Sorbent.

The coordination polymer was obtained based on cobalt trimesinate. It was characterized by elemental analysis, IR spectroscopy, X-ray diffraction analysis and scanning electron microscopy. The polymer was studied as a sorbent for solid-phase extraction of tetracycline antibiotics. Cobalt trimesinate had a high adsorption capacity (400 mg/g). Antibiotic adsorption followed the pseudo-second-order kinetic model and the Freundlich isotherm model. The process proceeded spontaneously, as indicated by the calculated thermodynamic parameters. The resulting coordination polymer has good stability and recyclability. The possibility of using cobalt trimesinate for the determination of tetracycline in various milk samples was investigated. This work holds great promise for the development and application of a cobalt trimesinate-based coordination polymer for use in sample preparation to replace the time-consuming vacuum evaporation procedure with a relatively simple solid-phase extraction procedure.

Crystallization of sucrose by using microwave vacuum evaporation

Sucrose crystallization was performed by using a custom designed microwave vacuum evaporation system. Process was designed to mimic a semi-batch crystallization starting from beet syrup concentration to crystal slurry formation. The effect of microwave power and feeding time on the process yield and product attributes (particle size, solution color and turbidity) were investigated. Microwave treatment was shown to affect the sucrose crystal morphology and the quality parameters significantly. Process yield was significantly affected by both crystallization power and feeding time (p < 0.05). Longer feeding time (15 min) and medium microwave power (30%) resulted in the highest process yield (∼55%). The results revealed that microwave processing can be a promising alternative over commercial crystallization.

An Investigation on CdSeTe/CdTe Stacks Deposited by Evaporation: Impact of Halide Treatment Depending on the Applied Surface

Among the methods applied to modify the characteristics of CdSeTe/CdTe stacks, one of the most well‐known and widely used procedures is the CdCl2 halide treatment. In this connection, the influence of CdCl2 on microstructural properties, phase distribution, and optical properties of CdSeTe/CdTe stack depending on location of the employed surface is investigated. In CdSeTe/CdTe stacks deposited by evaporation in vacuum, CdCl2 halide treatment is applied to the interface of CdSeTe and CdTe, the upper surface of CdTe, and both surface regions of the stack. CdCl2 treatment applied depending on the region has a definite effect on the phase structure, interlayer CdSexTe1−x alloying rate, and crystallization quality of the stack structure. Regardless of the applied region, all CdCl2‐treated stacks exhibit a granular and compact surface morphology. On the other hand, CdCl2 treated only on single surface results in a shift of the absorption edge to the shorter wavelength, but rather to the long spectral region for both surfaces. The photoluminescence spectra reveal the presence of band emissions of the CdTe layer and CdSeTe alloys. Overall, the findings of the study indicate that only the upper‐surface application of CdCl2 has more promising features for potential solar cell applications.

Vacuum Processed Metal Halide Perovskite Light‐Emitting Diodes

AbstractMetal halide perovskite light‐emitting diodes (PeLEDs) are expected to be the next‐generation display technology due to their unique optoelectronic properties. Currently, the external quantum efficiencies of PeLEDs based on solution‐processed fabrication methods already exceed 20%. However, there are still many challenges existing in solution‐based PeLEDs that inhibit their commercialization. Recently, vacuum deposition techniques of perovskites have drawn much attention because of the ability to grow dense and uniform large‐area perovskite films with precisely controlled thickness, which is compatible with state‐of‐the‐art organic LED manufacturing processes. Despite the promising prospects of vacuum‐based PeLEDs, some challenges remain to be addressed to achieve PeLEDs with both high efficiency and high stability that are required for practical applications such as active‐matrix displays. This requires precise control of the film morphology, composition, and interface during the deposition process through fine‐tuning of the substrate temperature, deposition rate, vacuum level, precursor formulation, and post‐treatment conditions. In this review, it focuses on the key requirements for vacuum‐processed PeLEDs, highlights the recent advances in materials and devices of PeLEDs, and emphasize vacuum evaporation methods as well as the corresponding device performance. Possible approaches to improve the efficiency and the long‐term operational stability of vacuum‐processed PeLEDs are discussed.

Controlled roll to roll pre-lithiation by lithium vacuum vapor deposition for high performance silicon based lithium-ion battery

Silicon oxides (SiOx) anode has attracted great interest for high-energy–density lithium-ion battery due to its extremely abundant reserves, low cost, and easy synthesis. Despite these merits, its low initial columbic efficiency (ICE) and poor cycle ability severely hinder it from widely using. Pre-lithiation methods are considered to be the effective strategies to overcome low ICE concerns. However, current pre-lithiation methods are always limited by their own drawbacks, such as complicated process and uncontrollable pre-lithiation degree. In this work, we reported a controlled roll-to-roll pre-lithiation method with lithium vacuum vapor deposition. Our pre-lithiation method can not only achieve controllable and uniform pre-lithiation degree of SiOx anode, but also is a process simplified design appropriate for large-scale applications. The electrochemical performance of our pre-lithiated anode achieved 10 % ICE improvement and much stable cycle, demonstrating promising potential for commercial applications.

Microstructure and Magnetism of Heavily Helium-Ion Irradiated Epitaxial Iron Films

This study reports on the microstructure and magnetism of pure iron irradiated with high doses of helium ions. Iron alloys are important structural materials used as components in fusion reactors, and a comprehensive database of their various properties has been developed. But little has been investigated on magnetic properties, in particular, the effects of high doses and helium cavities are lacking. Single-crystal iron films, with a thickness of 200 nm, were prepared using the ultra-high vacuum evaporation method. These films were then irradiated with 30 keV He+ ions at room temperature up to a dose of 18 dpa. X-ray diffraction measurements and cross-sectional transmission electron microscope observations revealed significant microstructural changes, including a large lattice expansion perpendicular to the film plane and the formation of high-density cavities after irradiation. However, the saturation magnetization and the shape of the magnetization curve showed almost no change, indicating the robustness of the magnetic properties of iron.

In the quest for sustainable management of liquid fraction of manure - Insights from a life cycle assessment

To mitigate the risk of eutrophication and minimize adverse environmental impacts, surplus manure in nitrate-vulnerable zones is frequently divided into a liquid and solid fraction. Managing the liquid fraction (LF) typically presents a greater challenge due to its substantial volume. This study aimed to assess the environmental impacts by region and trade-offs of managing surplus LF with inventory data from pilot facilities using a life cycle assessment (LCA). The LF-treatment technologies assessed were (i) nitrification-denitrification (NDN) with field application of effluent (ii) NDN with ammonia stripping and nitric acid scrubbing as a pre-treatment step followed by polishing in constructed wetlands, and (iii) nutrient up-concentration using vacuum evaporation and/or membrane filtration.The LCA results suggested that 60 to 80 % of the environmental impacts occurred locally. Nutrient up-concentration from LF via membrane filtration (reverse osmosis) and vacuum evaporation indicated a better environmental performance, albeit with high uncertainty when compared to the other scenarios. Although ammonia stripping-scrubbing showed environmental benefits, these were offset by high environmental burdens from fugitive N2O emissions and energy demand during NDN. Furthermore, the study identified that managing the effluent after NDN, a source of potassium (K), requires a nuanced approach from policymakers. Firstly, when K fertilization requirements are not met, direct land application of the effluent as a fertigation source can be a viable option. This minimizes the need for synthetic K fertilizer production and its ensuing freshwater ecotoxicity impacts. However, tertiary treatment of NDN effluent via constructed wetlands can be considered to prevent deterioration of soil from the influx of K. Policymakers are encouraged to engage with local stakeholders to tailor solutions based on these trade-offs. Furthermore, future research should focus on the implications of K on soil quality as well as the life span of nutrient up-concentration technologies for LF.

Highly conductive diamond skeleton reinforced Cu-matrix composites for high-efficiency thermal management

The weak interfacial bonding strength between diamond and copper intrinsically restricts the enhancement of the thermal conductivity of diamond particles/copper composites (abbreviated as DP/Cu). This work first proposed the diamond skeleton (DS) as the reinforcement element rather than dispersed diamond particles. The tungsten (W) transition layer (c.a. ∼300 nm thick) having adequate thermal expansion coefficient was sputtered onto the surface of DS via vacuum evaporation technology, aiming to improve the wettability between diamond and copper and accordingly increase the thermal conductivity of DS/copper composites extruded by gas pressure infiltration technique. The experimental results show that the coated W layer can effectively improve the wettability of the diamond surface and reduce the wettability angle from 108.6° to 13.2°. Raman and XRD spectra show that the W layer can, to a great extent, prevent the graphitization of the diamond surface. SEM and EDX evidence a continuous heat transfer path of DS inside the composites. The thermal conductivity of the DS/Cu composite with low diamond loading of 18.4 vol% reaches 575 W/mK, 43.3% higher than that of pure Cu. Finite element simulations show that DS exhibits excellent heat transfer characteristics, agreeing well with the thermal conductivity simulation results.

Experimental study of space lubricant evaporation in a high vacuum environment

The liquid lubricant evaporation in space applications poses significant challenges, raising the risk of inaccurate estimation of lubricant implementation and the potential contamination of satellite subsystems. The study of vacuum evaporation becomes highly relevant with the increasing use of liquid lubricants in satellite constellations. This research presents a novel methodology for assessing the lubricant evaporation rate, focusing on establishing a correlation between existing analytical models and experimental measurements. The obtained experimental results clearly demonstrate a disparity between the existing analytical models and the measured evaporated mass of vacuum base oils. Importantly, these results indicate higher evaporation rates predicted by the analytical approach. This emphasises the importance of refining the analytical models to accurately predict the amount of liquid lubricant evaporated.