Thermal Desorption Behavior Research Articles

Sublimation of volatiles from H2O:CO2 bulk ices in the context of comet 67P/Churyumov-Gerasimenko

Context. Comets are considered to be remnants from the formation of the Solar System. ESA’s Rosetta mission targeted comet 67P/Churyumov-Gerasimenko and was able to record high-quality data on its chemical composition and outgassing behaviour, including low abundances of N2 that are observed to be correlated with H2O and CO2 in approximately a 63:37 ratio. Aims. In this work, the thermal desorption behaviour of N2 in H2O:CO2 ices was studied in the laboratory to investigate the co-desorption behaviour of N2 within the two most abundant cometary ices in 67P and to derive desorbing fractions in different temperature regimes. Methods. H2O:CO2:N2 ices of various ratios were prepared in a gas mixing system and co-deposited at 15 K onto a copper sample holder. Sublimation of the ice was measured using temperature programmed desorption mass spectrometry. Quantitative values were derived for the fraction of N2 co-desorbing with CO2 and H2O respectively. To validate the results, H2O:CO2:13CO ices were prepared as well. Results. The experiments show that the co-desorption of N2 with CO2 in H2O:CO2:N2 ices depends on the bulk amount of CO2 present in the ice. The fraction of N2 trapped in H2O reduces as more N2 and CO2 are added to the mixture. CO behaves qualitatively similar to N2, but more CO is found to co-desorb with CO2. To reproduce the ratio of N2 desorbing with H2O over that of CO2 (N2(H2O)/N2(CO2)), our ice analogues need to contain ≥15% CO2, while 67P contains ≤7.5% CO2. Large fractions of N2 can be removed from the ice due to heating up to 70 K, but for ice that most closely resembles that of 67P, the loss fraction of pure phase N2 is expected to be ≤20%. Therefore, N2 is suggested to be a minor carrier of nitrogen in the comet.

Insights into the role of VOCs properties on thermal desorption behaviors of two porous polymeric resins

Desorption is a critical process in the recovery or post-treatment of adsorbents saturated with volatile organic compounds (VOCs). In this study, the thermal desorption behaviors for eight VOCs on hypercrosslinked polymeric resin (HPR) and macroporous polymeric resin (MPR) were investigated through isothermal desorption and temperature programmed desorption (TPD). Compared with MPR, HPR with more micropores exhibited a lower desorption rate constant, lower desorption efficiency and higher desorption activation energy due to the strong binding energy generated between VOCs molecules and narrow micropores. As the polarizability of VOCs increased, the desorption rate constants on two porous polymeric resins decreased, while the desorption activation energy showed an incremental trend. Excellent linear correlations were observed between VOC polarizability and desorption rate constants (R2 = 0.957 for HPR and R2 = 0.940 for MPR) as well as between VOC polarizability and desorption activation energy (R2 = 0.981 for HPR and R2 = 0.969 for MPR). Furthermore, a polyparameter linear free energy relationship (PP-LFER) was developed to explore the influences of intermolecular interactions on desorption behaviors of VOCs on porous polymeric resins. The results indicated that the dispersive interaction, which is directly related to polarizability of VOCs, was the primary factor influencing the desorption activation energy of VOCs on porous polymeric resins. The find from this study helps evaluate fleetly and availably the desorption properties of VOCs based on their polarizability.

Changes in hydrogen states after interactions between hydrogen and stress-induced martensite transformation for Ni–Ti superelastic alloy

ABSTRACTChanges in hydrogen states after dynamic interactions between hydrogen and a stress-induced martensite transformation have been investigated for Ni–Ti superelastic alloy. After homogenised hydrogen concentration by aging, the interactions change the hydrogen thermal desorption behaviour. Hydrogen in a solid solution probably changes to hydrogen trapped in damage regions induced by the interactions, as reported previously. With time after the interactions, the amount of hydrogen desorbed at low temperatures (200–400°C) markedly increases, clearly indicating that hydrogen states further change from the states immediately after the interactions. In cyclic tensile deformation in the stress plateau region caused by stress-induced martensite and reverse transformations, the number of cycles to fracture substantially increases with time after the interactions. The present results indicate that hydrogen states further change to a nominally interacting state after the interactions despite the absence of dynamic structural changes and a hydrogen concentration gradient, thereby suppressing hydrogen embrittlement related to the martensite transformation of the alloy.

Identification and quantification of soil water components in kaolin by thermogravimetric and kinetic analysis

Different types of soil water, such as bound water and capillary water, have distinct effects on the physicochemical and engineering properties of soils, particularly unsaturated clayey soils. Therefore, it is crucial to develop an accurate and physically meaningful experimental method for identifying and quantifying these components. This study pioneers the use of a multi-step kinetic model to identify and quantify different soil water components across a wide range of relative humidity (RH) using thermogravimetric analysis (TGA) data. To validate the determined kinetic parameters (i.e., activation energy, preexponential factor, and reaction model) and the identification and quantification results of soil water components, TGA with multiple heating rates, nitrogen adsorption method, cation exchange capacity measurement, and nuclear magnetic resonance (NMR) were performed on kaolin samples equilibrated under various RH conditions. These experimental results cross-validate the superior performance of the kinetic model in determining soil water components and predicting the thermal desorption behaviors of soil water. Based on the cross-validation results, the soil water components obtained from the kinetic analysis are further identified as tightly-bound, loosely-bound, and capillary water, which exhibit variations consistent with empirical soil water isotherm models. The T2 cutoff value between bound and capillary water is determined to be 1.79 ms based on TGA and NMR results. The determined thermal kinetic parameters of different soil water components can exhibit their distinct retention mechanisms. The method and results in this study provide a new perspective on identifying different soil water components, as well as understanding the mechanism of soil-water interactions in unsaturated soils.

Characterization of Hydrogen Thermal Desorption Behavior and Enhancement of Hydrogen Embrittlement in Ni–Ti Superelastic Alloy Induced by Cathodic Hydrogen Charging in the Presence of Chloride Ions

Characterization of Hydrogen Thermal Desorption Behavior and Enhancement of Hydrogen Embrittlement in Ni–Ti Superelastic Alloy Induced by Cathodic Hydrogen Charging in the Presence of Chloride Ions

Thermal desorption mechanism of n-dodecane on unsaturated clay: Experimental study and molecular dynamics simulation

Thermal desorption technology can effectively remediate fuels-contaminated clayey soil. However, the microscopic mechanism for the contaminant desorption on clay is still unclear, especially with the existence of water on clay surfaces. In this study, a combination method including TGA experiments, multi-phase and multi-component kinetic models, and MD simulation was proposed to reveal the thermal desorption mechanism of n-dodecane in unsaturated clay. Results showed that the thermal desorption behavior of the free nonaqueous phase liquid (NAPL) and the adsorbed phase of n-dodecane or water could be identified by the multi-phase and multi-component kinetic models based on the desorption process rate obtained by thermogravimetric analysis (TGA) experiments. The activation energy of the NAPL phase (49–69.9 kJ/mol) was lower than the adsorbed phase (90 kJ/mol). The activation energy of the NAPL phase had the same linear relationship with its mass on kaolinite and montmorillonite, while adsorbed phase only existed on the kaolinite surface. MD simulation showed that water demonstrated competitive adsorption with n-dodecane on montmorillonite surfaces and prevented the formation of the adsorbed phase while having little influence on the n-dodecane adsorption on kaolinite surface, which agrees well with the kinetic analysis of the TGA experiments. With the combination of macroscopic experimental analysis and microscopic molecular simulation, it can be concluded that the mass of the NAPL phase limited the desorption behavior, while the interaction between the clay mineral surface and n-dodecane was the key factor that dominated the thermal desorption behavior of the adsorbed phase. The presented results provide new insight into the desorption mechanism of hydrocarbon on clay minerals, which is of significance for the design of thermal desorption remediation.

Towards Improved Humidity Sensing Nanomaterials via Combined Electron and NH3 Treatment of Carbon-Rich FEBID Deposits.

Focused Electron Beam Induced Deposition (FEBID) is a unique tool to produce nanoscale materials. The resulting deposits can be used, for instance, as humidity or strain sensors. The humidity sensing concept relies on the fact that FEBID using organometallic precursors often yields deposits which consist of metal nanoparticles embedded in a carbonaceous matrix. The electrical conductivity of such materials is altered in the presence of polar molecules such as water. Herein, we provide evidence that the interaction with water can be enhanced by incorporating nitrogen in the deposit through post-deposition electron irradiation in presence of ammonia (NH3). This opens the perspective to improve and tune the properties of humidity sensors fabricated by FEBID. As a proof-of-concept experiment, we have prepared carbonaceous deposits by electron irradiation of adsorbed layers of three different precursors, namely, the aliphatic hydrocarbon n-pentane, a simple alkene (2-methyl-2-butene), and the potential Ru FEBID precursor bis(ethylcyclopentadienyl)ruthenium(II). In a subsequent processing step, we incorporated C-N bonds in the deposit by electron irradiation of adsorbed NH3. To test the resulting material with respect to its potential humidity sensing capabilities, we condensed sub-monolayer quantities of water (H2O) on the deposit and evaluated their thermal desorption behavior. The results confirm that the desorption temperature of H2O decisively depends on the degree of N incorporation into the carbonaceous residue which, in turn, depends on the chemical nature of the precursor used for deposition of the carbonaceous layer. We thus anticipate that the sensitivity of a FEBID-based humidity sensor can be tuned by a precisely timed post-deposition electron and NH3 processing step.

Thermal desorption characteristics of the adsorbate in activated carbon based on a two-dimensional heat and mass transfer model

• A multiphase model of heat and mass transfer in porous media is established. • The multiphase model is validated to simulate the thermal desorption behavior of activated carbon adsorption. • A simplified evaporation rate formula is proposed, and the agreement between the model and the experimental results are verified. • The effect of high thermal conductivity activated carbon on thermal regeneration time is analyzed. • The effects of polar and non-polar adsorbates on model accuracy are analyzed. Thermal desorption of adsorbate in activated carbon is the main part in the thermal regeneration process of spent activated carbon, and previous studies have carried out a series of numerical simulations on it. However, since activated carbon is a porous medium, the heat and mass transfer in activated carbon is different from that in solid. In this paper, a multiphase model of heat and mass transfer in porous media was constructed to study the thermal desorption characteristics of adsorbate in spent activated carbon. In addition, a simplified evaporation rate formula is proposed in this paper, and the agreement between the simulation and the experimental results is verified. When the surroundingtemperature is less than 673.15 K, increasing the surrounding temperature has a significant effect on reducing the thermal desorption time of the adsorbate. Using activated carbon with a thermal conductivity of 5 W / m ∙ K can save about 40% of energy consumption. The model established in this paper can accurately simulate the thermal desorption of adsorbate in activated carbon, which is helpful to deeply understand the mechanism of activated carbon thermal regeneration. In engineering practice, the model can provide technical support for optimizing the thermal regeneration process of spent activated carbon and reducing energy consumption in a targeted manner.

Effects of mineral species and petroleum components on thermal desorption behavior of petroleum-contaminated soil

Thermal desorption (TD) behavior of high-concentration petroleum-contaminated soil (PCS) is affected by soil composition, especially inorganic minerals. In this study, the TD behavior of petroleum-contaminated quartz (original mineral) and kaoline (clay mineral) were compared with those of pure petroleum (Petro-free); their “saturate, aromatic, resin, and asphaltenes” (SARA) fractions were investigated using thermogravimetry and differential thermogravimetry (TG-DTG). The modelling of the petroleum removal kinetics was also analyzed to provide insights into the mechanism. The results revealed that the limiting factor controlling the desorption of petroleum from quartz (Petro-Qtz) and kaoline (Petro-Kln) is the minerals, which increased the effective TD temperature by 200 °C and decreased TD efficiency by 2%. Compared to Petro-Qtz, Petro-Kln showed a lower desorption efficiency of 5% and the process was accomplished at a higher temperature of 100 °C. The investigation on SARA fractions indicated that polar fractions (i.e., aromatics, resins, and asphaltenes) were strongly captured by the minerals. The increment of the TD temperature of petroleum (resins–160 °C > aromatics–20 °C > saturates–5 °C) increased with the polarity of petroleum components. These results could be validated by thermogravimetry-gas chromatography/mass spectroscopy (TG-GC/MS) through the delayed desorption of naphthalene and acenaphthene. Furthermore, the increment of the TD temperature of SARA fractions on kaoline was higher than those on quartz. This makes sense because the kaoline decreased the diffusion of hydrocarbons due to its porosity features and higher specific surface area (kaoline 5.3300 m2 g−1, quartz 0.1153 m2 g−1). In addition, the analysis of the desorption kinetic models showed that the observed hysteresis was related to the diffusion barrier caused by chemisorption (n＜1). In consequence, the Petro-Kln showed a lower desorption efficiency, a slower desorption, and as a result, a higher energy consumption (0.476 kW h) for thermal remediation than Petro-Qtz (0.238 kW h).

HCN Snow Lines in Protoplanetary Disks: Constraints from Ice Desorption Experiments

HCN is among the most commonly detected molecules in star- and planet-forming regions. It is of broad interest as a tracer of star formation physics, a probe of nitrogen astrochemistry, and an ingredient in prebiotic chemical schemes. Despite this, one of the most fundamental astrochemical properties of HCN remains poorly characterized: its thermal desorption behavior. Here, we present a series of experiments to characterize the thermal desorption of HCN in astrophysically relevant conditions, with a focus on predicting the HCN sublimation fronts in protoplanetary disks. We derive HCN–HCN and HCN–H2O binding energies of 3207 ± 197 and 4192 ± 68 K, which translate to disk midplane sublimation temperatures around 85 and 103 K. For a typical midplane temperature profile, HCN should only begin to sublimate ∼1–2 au exterior to the H2O snow line. Additionally, in H2O-dominated mixtures (20:1 H2O:HCN), we find that the majority of HCN remains trapped in the ice until H2O crystallizes. Thus, HCN may be retained in disk ices at almost all radii where H2O-rich planetesimals form. This implies that icy body impacts to planetary surfaces should commonly deliver this potential prebiotic ingredient. A remaining unknown is the extent to which HCN is pure or mixed with H2O in astrophysical ices, which impacts the HCN desorption behavior as well as the outcomes of ice-phase chemistry. Pure HCN and HCN:H2O mixtures exhibit distinct IR bands, raising the possibility that the James Webb Space Telescope will elucidate the mixing environment of HCN in star- and planet-forming regions and address these open questions.

Thermal desorption behavior of fluoroquinolones in contaminated soil of livestock and poultry breeding

As a kind of typical veterinary drug, fluoroquinolone antibiotics (FQs) are widely used in the field of livestock and poultry breeding, but these FQs escape to surrounding soil through various pathways, polluting soil through long-term accumulation. Current study proposed a clean technology named thermal desorption to deal with FQs contaminated soils. It was observed that time, temperature and soil particle size were the critical factors in FQs thermal desorption. Results of the study showed that higher temperature was more effective in the removal of FQs, while removal of FQs attached with finer particles was more difficult compared to coarse particles. Fine soil particles (0.6–0.85 mm) were decontaminated up 99.4% when treated with 400 °C for 60min. Thermal desorption of FQs from contaminated soil was governed by first-order kinetics. Based on the detection of exhaust gas components, a possible thermal desorption mechanism was proposed. Study suggested that thermal desorption was a clean and effective remediation method to treat FQs-contaminated soils without generating any further waste.

Effects of Mineral Species and Petroleum Components on Thermal Desorption Behaviors of Petroleum-Contaminated Soil

Effects of Mineral Species and Petroleum Components on Thermal Desorption Behaviors of Petroleum-Contaminated Soil

Effect of He content on the evolution of He bubbles and He thermal desorption behaviors in FeCr based nanocrystalline film

He-charged FeCr based nanocrystalline films were fabricated at room temperature in a mixed atmosphere of He and Ar by radio frequency magnetron sputtering. The effect of the He/Ar ratio on the crystalline structure, surface morphology, He desorption behaviors, and the size and distribution of He bubbles had been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal desorption spectrum (TDS), and transmission electron microscopy (TEM), respectively. The results of XRD revealed that He-charged FeCr based films had a typical bcc structure. Surface SEM images showed that the grain size of FeCr based films decreased with the He/Ar ratio increasing. The results of TDS profiles exhibited that these desorption peaks corresponded to the release of He atoms dissociated from surface, HenV (2≤n≤6), HenVm (1≤n, 2≤m), and He bubbles, respectively. Based on the results of TEM observation, the density of He bubbles was proportional to the He/Ar ratio, while the size of He bubbles could be scarcely influenced by the He/Ar ratio.

Comparative study of structural order, thermal desorption behavior, and work function change of self-assembled monolayers of pentafluorobenzenethiols and tetrafluorobenzenethiols on Au(1 1 1)

The surface and interface structures, thermal desorption behaviors, and electronic properties of pentafluorobenzenethiol (PFBT) and tetrafluorobenzenethiol (TFBT) self-assembled monolayers (SAMs) on Au(111) formed at different vapor deposition temperatures (298, 323, and 348 K) were examined to understand the effect of dipole directions in fluorinated aromatic thiol SAMs using scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), thermal desorption spectroscopy (TDS), and Kelvin probe (KP) measurements. Molecular-scale STM observations revealed that PFBT SAMs on Au(111) had a well-ordered phase with a c(2 × √3) structure at 348 K, whereas TFBT SAMs showed a well-ordered phase with a (2√3 × 8√2)R30° structure at 323 K.TDS and XPS measurements also demonstrated thatPFBT and TFBT SAMs showed significantly different thermal desorption behaviorsand interface structures due toopposite directions of molecular dipole moments. The KP measurements showed that the extent of the work function change of SAM-modified Au substrates was lowest in most highly-ordered PFBT and TFBT SAMs formed at 348 K and 323 K, respectively, regardless of chemisorbed surface coverage. These findings revealed that the degree of structural order of SAMs is a more significant factor in causing the depolarization effect rather than chemisorbed surface coverage.

Study on the remediation of tetracycline antibiotics and roxarsone contaminated soil.

Antibiotics are commonly used in livestock and poultry breeding along with organic arsenic. Through long-term accumulation, they can enter into the surrounding soil through various pathways and contaminate the soil. In this paper, tetracycline antibiotics (TCs) and roxarsone (ROX) contaminated soil were used as the representatives of the two kinds of veterinary drugs contaminated soil, respectively, to study the thermal desorption behavior and arsenic stabilization process. Different parameters like heating temperatures, heat duration, stabilizer type and dosage were optimized for effective removal of TCs and ROX. Furthermore, TCs and ROX removal path and ROX stabilization mechanism were explored. Results of the study showed that over 98% of tetracycline antibiotics and roxarsone were effectively removed at 300°C for 60min. The heat treatment process of TCs contaminated soil was controlled by the first-order kinetics. Based on the detection of degradation products and thermogravimetric analysis, the possible thermal degradation path of TCs and ROX was proposed. Addition of FeSO4.7H2O (10% by weight) as stabilizer during the heat treatment process yielded 96.7% stabilization rate. Through the analysis of arsenic fractions, valence and the characterization of soil samples collected after the heat treatment, mechanism of arsenic stabilization in ROX was explored. The results show that thermal treatment combined with chemical stabilization technology can not only degrade TCs and ROX efficiently and completely, but also convert organic arsenic into inorganic state, which is conducive to better stabilization, and finally achieve effective and safe remediation of this kind of contaminated soil.

Marked Degradation of Tensile Properties Induced by Plastic Deformation after Interactions between Strain-Induced Martensite Transformation and Hydrogen for Type 316L Stainless Steel

Marked degradation of tensile properties induced by plastic deformation after dynamic interactions between strain-induced martensite transformation and hydrogen has been investigated for type 316L stainless steel by hydrogen thermal desorption analysis. Upon modified hydrogen charging reported previously, the amount of hydrogen desorbed in the low temperature range increases; the degradation of tensile properties induced by interactions between plastic deformation and hydrogen at 25 °C or induced by interactions between martensite transformation and hydrogen at −196 °C occurs even for the stainless steel with high resistance to hydrogen embrittlement. The hydrogen thermal desorption behavior is changed by each interaction, suggesting changes in hydrogen states. For specimen fractured at 25 °C, the facet-like morphology and transgranular fracture are observed on the outer part of the fracture surface. At −196 °C, a quasi-cleave fracture is observed at the initiation area. Modified hydrogen charging significantly interacts both plastic deformation and martensite transformation, eventually enhancing the degradation of tensile properties. Upon plastic deformation at 25° C after the interactions between martensite transformation and hydrogen by straining to 0.2 at −196 °C, cracks nucleate in association with martensite formed by the interactions at −196 °C and marked degradation of tensile properties occurs. It is likely that the interactions between martensite transformation and hydrogen induce damage directly related to the degradation, thereby affecting subsequent deformation. Upon dehydrogenation after the interactions between the martensite transformation and hydrogen, no degradation of tensile properties is observed. The damage induced by the interactions between martensite transformation and hydrogen probably changes to harmless defects during dehydrogenation.

Coupling Filter-Based Thermal Desorption Chemical Ionization Mass Spectrometry with Liquid Chromatography/Electrospray Ionization Mass Spectrometry for Molecular Analysis of Secondary Organic Aerosol.

Filter-based thermal desorption (F-TD) techniques, such as the filter inlet for gases and aerosols, are widely employed to investigate the molecular composition and physicochemical properties of secondary organic aerosol (SOA). Here, we introduce an enhanced capability of F-TD through the combination of a customized F-TD inlet with chemical ionization mass spectrometry (CIMS) and ultraperformance liquid chromatography/electrospray ionization mass spectrometry (UPLC/ESI-MS). The utility of F-TD/CIMS + UPLC/ESI-MS is demonstrated by application to α-pinene ozonolysis SOA for which increased filter aerosol mass loading is shown to slow the evaporation rates of deposited compounds. Evidence for oligomer decomposition producing multimode F-TD/CIMS thermograms is provided by the measurement of the mass fraction remaining of monomeric and dimeric α-pinene oxidation products on the filter via UPLC/ESI-MS. In situ evaporation of aerosol particles suggests that α-pinene-derived hydroperoxides are thermally labile; thus, analysis of particle-phase (hydro)peroxides via F-TD may not be appropriate. A synthesized pinene-derived dimer ester (C20H32O5) is found to be thermally stable up to 200 °C, whereas particle-phase dimers (C19H30O5) are observed to form during F-TD analysis via thermally induced condensation of synthesized pinene-derived alcohols and diacids. The complementary F-TD/CIMS + UPLC/ESI-MS method offers previously inaccessible insight into the molecular composition and thermal desorption behavior of SOA that both clarifies and expands on analysis via traditional F-TD techniques.

Effect of He content on microstructure, mechanical properties and He thermal desorption behavior of W film fabricated by RF magnetron sputtering

In order to study the effect of He content on microstructure, mechanical properties and He thermal desorption behavior of W film, He-charged W films on Si substrates were fabricated by a radio frequency (RF) magnetron sputtering device in different He/Ar mixture gases. The deposited W films had a typical columnar structure, and the grain size of W films decreased as He/Ar ratio increased by means of the observation of scanning electron microscopy (SEM). X-ray diffraction (XRD) analysis confirmed that W films had a typical bcc structure, and the introduced He atoms can refine grain size and increase the lattice strain. TEM analysis showed that large numbers of He bubbles can be formed in W films, as well as the size and density of these He bubbles increased with the increase of the He/Ar ratio. The shape of He bubbles trapped by different sites also had some differences. Thermal desorption spectra (TDS) revealed that He content increased with He/Ar ratio increasing and different types of He atoms could be introduced into W films. The hardness value measured by nanoindentation tests increased with He/Ar ratio increasing, which demonstrated that nano-sized He bubbles could strengthen W films.

Eggshell and plant ash addition during the thermal desorption of polycyclic aromatic hydrocarbon-contaminated coke soil for improved removal efficiency and soil quality.

Thermal desorption (TD) technology is the preferred treatment technology for treating soil contaminated by organic compounds. Under laboratory conditions, eggshell and plant ash were studied as additives during thermal desorption to further improve the soil thermal desorption efficiency and the quality of soil after thermal desorption. The results showed that temperature was still an important factor affecting the soil quality and removal efficiency of PAHs (polycyclic aromatic hydrocarbons). The efficiency of the thermal desorption of soil was significantly improved (from 91.7 to 96.6%) by adding two additives, and the agglomeration of the soil was alleviated to some extent according to the decreased amount of large soil particle (100-400μm). Moreover, the TOC (total organic carbon) and CEC (cation exchange capacity) of the soil were increased. This work suggested that the addition of similar alkaline additives to the soil during thermal desorption might have a positive impact on both thermal desorption behavior and soil quality.

Thermal desorption behavior of hemiacetal, acetal, ether, and ester oligomers

Thermal desorption methods are widely used in the aerosol community to obtain information on particle volatility, and are often coupled with mass spectrometry to separate chemical components prior to analysis. One of the challenges of using these methods is that it is not yet clear how different components respond to temperature, in particular whether they desorb intact or decompose by reversible or irreversible reactions prior to desorption. In this study, we analyzed the thermal desorption behavior of four major classes of oligomers: hemiacetals, acetals, ethers, and esters, which are potentially present in secondary organic aerosol (SOA) and are primarily formed through particle-phase accretion reactions. The results show that when all four of these oligomers are desorbed in our thermal desorption particle beam mass spectrometer at ∼160 °C on millisecond timescales (real-time analysis) they reach the ionization region as the intact oligomer. This is also true for acetal, ether, and ester oligom...