Liquid Compounds Research Articles

Studies of temperature dependent Raman spectroscopy of two nematic liquid crystalline compounds of homologous series

Raman spectroscopy is an important tool to understand the structural and molecular behaviour of the liquid crystals when they undergo through different temperatures. It also helps to understand the different phase changes of the liquid crystal material as temperature changes. In this work, the structural properties of two nematic liquid crystals having relatively high clearing temperature namely 4 butylcyclohexyl-3, 5-difluoro-4- isothiocyanato biphenyl and 4-pentylcyclohexyl-3, 5-difluoro-4-isothiocyanato biphenyl are studied. The study is done using temperature dependent Raman spectroscopy. From the studies of the two compounds it has been found that the experimental values are agree well with the various functional groups and different bond assignments recorded in literature. This agreement validates the presence of different functional groups and different stretching bonds in the two studied liquid crystal compounds. Deformations of some of the peak positions of the two liquid crystal compounds have been observed with the change in phase at different temperature. Also to understand the behaviour of the Raman peak near the clearing temperatures of the liquid crystal compounds the linewidth of the different peak values at different temperature have also been studied. From the line width study, the various phase transition temperatures of the two liquid crystalline compounds can be confirmed.

From Liquid to Solid: Cocrystallization as an Engineering Tool for the Solidification of Pyruvic Acid

Pyruvic acid is an organic compound used in various fields (e.g., the pharmaceutical, cosmetic, food, and chemical industries) and subject to constantly growing demand. Pyruvic acid is liquid at room temperature, rendering manipulation less straightforward. Furthermore, in the liquid phase, pyruvic acid is air-sensitive. We here present a multi-component crystal engineering strategy to render pyruvic acid solid under ambient conditions, focusing on cocrystallization and salt formation. Out of 73 screened cocrystal and salt formers, eight were found to form novel crystalline forms with pyruvic acid. Four of these were studied in detail, with pyruvic acid stable in a solid phase at temperatures up to 120 °C. These results illustrate the effectiveness of cocrystallization as a tool to convert unstable liquid compounds into stable crystalline solid forms.

A Label-Free Electrochemical Biosensor for Homocysteine Detection Using Molecularly Imprinted Polymer and Nanocomposite-Modified Electrodes.

An essential biomarker for the early detection of cardiovascular diseases is serum homocysteine (Hcy). In this study, a molecularly imprinted polymer (MIP) and nanocomposite were used to create a label-free electrochemical biosensor for reliable Hcy detection. A novel Hcy-specific MIP (Hcy-MIP) was synthesized using methacrylic acid (MAA) in the presence of trimethylolpropane trimethacrylate (TRIM). The Hcy-MIP biosensor was fabricated by overlaying the mixture of Hcy-MIP and the carbon nanotube/chitosan/ionic liquid compound (CNT/CS/IL) nanocomposite on the surface of a screen-printed carbon electrode (SPCE). It showed high sensitivity, with a linear response of 5.0 to 150 µM (R2 of 0.9753) and with a limit of detection (LOD) at 1.2 µM. It demonstrated low cross-reactivity with ascorbic acid, cysteine, and methionine. Recoveries of 91.10-95.83% were achieved when the Hcy-MIP biosensor was used for Hcy at 50-150 µM concentrations. The repeatability and reproducibility of the biosensor at the Hcy concentrations of 5.0 and 150 µM were very good, with coefficients of variation at 2.27-3.50% and 3.42-4.22%, respectively. This novel biosensor offers a new and effective method for Hcy assay compared with the chemiluminescent microparticle immunoassay at the correlation coefficient (R2) of 0.9946.

Selective extraction of polyhydroxy compounds using hydrophobic ionic liquids

Polyhydroxy compounds such as sugar alcohols /derivatives are high value chemicals with application potential in medicine, materials and other fields. Researches on preparation and selective extraction of polyhydroxy compounds have attracted wide attention in the world. However, the selective extraction of polyhydroxy compounds is still a major challenge.In this paper, hydrophobic ionic liquids (ILs) 1-butyl-3-methylimidazole bis(trifluoromethanesulfon)imide salt ([Bmim][Ntf2]), 1-ethyl-3-methylimidazole bis(trifluoromethanesulfon)imide salt ([Emim][Ntf2]) and 1-allyl-3-methylimidazole bis(trifluoromethanesulfon)imide salt ([Amim][Ntf2])) were used for the dissolution and selective extraction of polyhydroxy compounds. In addition, the interaction between ionic liquids and polyhydroxy compounds was characterized and analyzed by NMR and contact angle analysis. The partition coefficients of polyhydroxy compounds in water and hydrophobic ionic liquids were also investigated. It was shown that among the ILs used, the solubility of polyhydroxy compounds fluctuated strongly (from 0 wt% to 19.50 wt%), and the solubility in [Amim][Ntf2] was the highest. These hydrophobic ionic liquids showed strong selective extraction ability when fractionating mixtures composed of sugar alcohols and their dehydrated derivatives (1:1, w / w). The results showed that the purities of isosorbide and isomannide separated were more than 99.60 wt% and 99.99 wt% respectively. Polyhydroxy compounds dissolved in hydrophobic ionic liquids could be directly extracted by water without chemical modification. The regeneration rate of ionic liquids reached 93.22%−97.04%. The NMR characterization of the regenerated ionic liquid showed that water could fully extract polyhydroxy compounds dissolved in the ionic liquids and the structure of the regenerated ionic liquid did not change. It was promising to construct a green and efficient method for fractionating such polyhydroxy compounds based on hydrophobic ionic liquids, and it is suggested to further strengthen the research in this field.

A New Herbal Medicine Formulation with Potential Anti-scabies Properties to Treat Demodex and Sarcoptes Parasites

Scabies is considered an external parasite notorious for its high prevalence causing severe and contagious skin lesions in humans and animals worldwide. This study has introduced a medicine to treat dogs infested with scabies (variants of Demodex, Sarcoptes, Psoroptes, Otodectes, etc.). The present study offers a no-side-effect herbal formulation to treat dogs infested with scabies. Unlike oral and injectable medicines, which take the form of an ointment and are topically applied on-site, this medicinal formulation can be easily used without concerns over its side effects or consumption dosages. This medicinal formulation requires no skin rinsing due to its herbal and high skin absorption properties, as recovery may take less than a month with a maximum of two times of application. To carry out the experiment, 25 sick dogs with various breeds and ages suspected of scabies were gathered. Following accurate morphological examinations of all the samples, a deep skin chip of the lesion site was provided, which was examined by a microscope. Then, 13 dogs (Mix, Terrier, Pug, Husky, Spitz) were infested with Demodex scabies and 12 dogs (Pittbull, Mix, Shih Tzu, Terrier, Boxer, Setter) with Sarcoptic scabies. The prepared product was topically administered at a constant 2% dosage to the bodies of all the samples. To prepare the ointment, 1 g of Borax (Na₂B₄O₇·10H₂O) was first dissolved in 35 g deionized water and heated to 70°C. Then, 45 g of liquid paraffin (CnH2n+2) was mixed with 1 g of Carvacrol (C10H14O) and 1 g of geranium (C10H18O) and stirred well to become a phase. Later, 17 g of the melted beeswax (C15H31COOC30H61) was added to the liquid paraffin compound. In the end, the aqueous phase was added to the oil phase, and the mixture process immediately began in one direction with a glass stirrer and continued until the product cooled down. Essential oils (EO) was obtained by steam distillation of fresh Thyme and Rose-Acented Geranium in a stainless steel distillation apparatus (alembic) for 3 h. The main components of the essential oils used in the formulation were performed using a Hewlett-Packard GC system interfaced with a mass spectrometer equipped with an HP5-MS capillary column (30 m, 0.32 mm, 0.25 µm film thicknesses). For GC–MS detection, electron ionization with ionization energy of 70 eV was used. To examine the presence of scabies, weekly skin sampling was performed, and the treatment continued until 30 days, when no skin chip of the scabies was noted. The findings revealed that the formulation developed no side effects and removed the daily use, as it could be administered once or twice a week. Also, complete recovery of scabies in all the breeds was found to be less than a month at most. This medicinal formulationcan be easily used without concerns over its side effects or consumption dosages. This study introduced a herbal formulation with effective herbal ingredients without any side effects to treat the sarcoptes and demodex parasites; unlike other chemical compounds, this medicinal formulation has no side effects, while some other formulations could develop side effects.

The role of porosity and acidity in the catalytic upcycling of polyethylene

Plastics have become fundamental and widespread materials in our everyday life. Nowadays, the most demanded plastics are polyolefins, accounting for nearly half of the Global plastic production. However, the end-of-life disposal of these materials is an issue inevitably connected to their increased production. Among chemical recycling techniques, the most thoroughly investigated process is the catalytic pyrolysis, showing a vast panorama of different set-ups optimized for the major production of either gaseous or liquid compounds. In this contribution a series of mesoporous silica-based materials, either pure SiO2 or substituted with Zr and Al, were systematically synthetized varying both porous framework and surface acidity, in the attempt of rationalizing the effect of each parameter (deeply characterized by physico-chemical methods) on the catalytic pyrolysis of linear low-density polyethylene (LLDPE). The synthetized materials together with some zeolites and aluminas reference samples were tested towards LLDPE degradation in a batch reactor set-up optimized for the formation and accumulation of the gaseous compounds, coupled with IR spectroscopy for in situ monitoring the evolution of the most abundant species (mostly propylene and branched C4-C6 olefins, together with a minor fraction of ethylene and short hydrocarbons). This work points out the necessity of the presence of Brønsted acid sites for a good activity (in terms of both the yield of gaseous products and lowering of the process temperature), but it also reveals a non-negligible role of the Lewis acid sites and it warns about the importance of controlling not only the amount of acid sites but also their strength.

The advantage of a two-stage nitrification method for fertilizer recovery from human urine

Recycling nutrients (nitrogen, phosphorus, and potassium) from human urine can potentially offset more than 13% of global agricultural fertilizer demand. Biological nitrification is a promising method for converting volatile ammonia in high-strength human urine into stable ammonium nitrate (a typical fertilizer), but it is usually terminated in the intermediate production of nitrite due to the inhibition of nitrite-oxidizing bacteria by free nitrous acid (FNA). This study aimed to develop a stable nitrification process in a unique two-stage bioreactor by removing critical barriers associated with FNA inhibition. Experimental results show that half of the ammonium in high-strength urine was successfully converted into nitrate, forming valuable ammonium nitrate (with a nitrogen concentration greater than 1500 mg N/L). The ammonium nitrate solution could retain most phosphorus (75% ± 3%) and potassium (96% ± 1%) in human urine, resulting in nearly full nutrient recovery. Once concentrated, the liquid compound fertilizer of ammonium nitrate was generated. Based on an assessment of economic and environmental impacts at the urban scale, urine diversion for nutrient recovery using a technical combination of nitrification and reverse osmosis could reduce total energy input by 43%, greenhouse gas emission by 40%, and cost by 33% compared to conventional wastewater management. Further research is needed to optimize the two-stage nitrification method on a larger scale.

Liquid Biopsy-Based Volatile Organic Compounds from Blood and Urine and Their Combined Data Sets for Highly Accurate Detection of Cancer.

Liquid biopsy is seen as a prospective tool for cancer screening and tracking. However, the difficulty lies in effectively sieving, isolating, and overseeing cancer biomarkers from the backdrop of multiple disrupting cells and substances. The current study reports on the ability to perform liquid biopsy without the need to physically filter and/or isolate the cancer cells per se. This has been achieved through the detection and classification of volatile organic compounds (VOCs) emitted from the cancer cells found in the headspace of blood or urine samples or a combined data set of both. Spectrometric analysis shows that blood and urine contain complementary or overlapping VOC information on kidney cancer, gastric cancer, lung cancer, and fibrogastroscopy subjects. Based on this information, a nanomaterial-based chemical sensor array in conjugation with machine learning as well as data fusion of the signals achieved was carried out on various body fluids to assess the VOC profiles of cancer. The detection of VOC patterns by either Gas Chromatography-Mass Spectrometry (GC-MS) analysis or our sensor array achieved >90% accuracy, >80% sensitivity, and >80% specificity in different binary classification tasks. The hybrid approach, namely, analyzing the VOC datasets of blood and urine together, contributes an additional discrimination ability to the improvement (>3%) of the model's accuracy. The contribution of the hybrid approach for an additional discrimination ability to the improvement of the model's accuracy is examined and reported.

Characterization of an odor permeable membrane device for the storage of explosives and use as canine training aids.

The storage and use of explosives is regulated at the state and federal level, with a particular focus on physical security and rigorous accounting of the explosive inventory. For those working with explosives for the training and testing of explosive-detecting canines, cross-contamination is an important concern. Hence, explosives intended for use with canine teams must be placed into secondary storage containers that are new, clean, and airtight. A variety of containers meet these requirements and include screw-top glass jars (e.g., mason jars). However, an additional need from the explosive-detecting canine community is secondary containers that can also be used as training aids whereby the volatiles emitted by explosives are emitted in a predictable and stable manner. Currently, a generally accepted method for the storage of explosives and controlled emission of explosive vapor for canine detection does not exist. Ideally, such containers should allow odor to escape from the training aid but block external contaminates such as particulates or other volatiles. One method in use places the explosive inside a permeable cotton bag when in use for training and then stores the cotton bag inside an impermeable nylon bag for long-term storage. This paper describes the testing of an odor permeable membrane device (OPMD) as a new way to store and deploy training aids. We measured the evaporation rate and flux of various liquid explosives and volatile compounds that have been identified in the headspace of actual explosives. OPMDs were used in addition to traditional storage containers to monitor the contamination and degradation of 14 explosives used as canine training aids. Explosives were stored individually using traditional storage bags or inside an OPMD at two locations, one of which actively used the training aids. Samples from each storage type at both locations were collected at 0, 3, 6, and 9months and analyzed using Fourier Transform Infrared (FTIR) Spectroscopy and Gas Chromatography-Mass Spectrometry (GC-MS) with Solid-Phase Microextraction (SPME). FTIR analyses showed no signs of degradation. GC-MS identified cross-contamination from ethylene glycol dinitrate (EGDN) and/or 2,3-dimethyl-2,3-dinitrobutane (DMNB) across almost all samples regardless of storage condition. The contamination was found to be higher among training aids that were stored in traditional ways and that were in active use by canine teams.

Recovery of Ammonium from Biomass-Drying Condensate Via Ion Exchange and Its Valorization as a Fertilizer

In this study, an industrial biomass-drying wastewater condensate containing > 3200 mg/L NH4+ and >8900 mg/L CH3COO− was treated in ion-exchange columns for the recovery of NH4+. Two commercial resins (CS12GC and CS16GC) were studied on laboratory and pilot scales. CS16GC outperformed CS12GC by achieving better separation at the condensate temperature (60 °C), which was energy-efficient regarding NH4+ removal. K3PO4 was used for regeneration to produce a liquid compound fertilizer containing nutrient elements (N, K, and P) as a byproduct. The N/K ratio in the byproduct was found to be adjustable by varying the operating parameters. Regeneration with 2 mol/L K3PO4 gave a higher regeneration efficiency (97.67% at 3 BV and ~100% at 4 BV). The stability tests performed on a laboratory scale showed that the cyclic runs of the column separation process were steady and repeatable. Based on the outcomes of the laboratory-scale tests, the pilot-scale tests applied a loading volume of 7 BV. The pilot column purified the feed and achieved the target NH4+ level in the treated effluent within the seven tested cycles, revealing that the industrial application of the cation ion-exchange resin CS16GC is worth further study.

An update on liquid heat capacity estimations of cyclic organic compounds by group additivity and their application in estimations of complex molecules by synthetic and retrosynthetic analysis

Group additivity is very useful technique for estimating heat capacities of organic substances. This contribution examines a concern regarding the use of this technique when estimating the heat capacities of large molecules. The concern addresses the observation of a tendency of group values, particularly liquids, to overestimate heat capacities of large cyclic or highly branched liquid compounds of a commonly used group method. Group values for estimating cyclic liquids have been updated. In addition, a protocol is also described for the estimations of both liquid and solid heat capacities of large complex molecules at T = 298.15 K that takes advantage of currently available experimental data of potential precursors. The materials estimated using this protocol include several natural products, a statin and a number of steroids. Results are compared to available experimental data.

The effect of position of (-)-menthyl on the mesomorphic and photoisomerization behavior in azobenzene chiral liquid crystals

As the mesomorphic type of liquid crystals could be largely altered by the molecular chirality, we herein explored the effect of position of chiral (-)-menthyl on the mesomorphic and photoisomerization behavior in azobenzene liquid crystals. By modifying the position of chiral (-)-menthyl in the menthol based liquid crystal compounds through gradually increasing the alkyl chain length of the dicarboxylic spacer, seven new chiral liquid crystal compounds 4-(4-menthyloxy-n-oxoalkanoyloxy)-4′-(4-ethoxybenzoyloxy) azobenzene MnAZO2B (n = 2–8) were prepared. A combination of analysis methods was conducted to systematically investigate their structures, mesophase behaviors and optical properties. The length and parity of the flexible spacers has a dramatic influence on the mesomorphic behaviors, and an odd-even effect is observed for these chiral liquid crystal compounds.

Improvement of the heat resistance of a liquid mold compound by bismaleimide resin

For next-generation power semiconductors, a highly heat-resistant liquid mold compound was developed based on an epoxy resin having a functional group that can react with bismaleimide (BMI) resin. A liquid resin with a maleimide skeleton was created by prereacting BMI, which has a low melting point of 70–150 °C, with an epoxy resin having allyl and epoxide groups. The maleimide-skeleton epoxy resin was able to precure at ≤150 °C using peroxide and imidazole curing agents. The liquid maleimide-modified epoxy mold compound (EMC) containing silica filler had not a clear glass transition temperature, so the change in physical properties to temperature is very small. This study compared the heat resistance of the developed maleimide-modified liquid mold compound with a general-purpose EMC and silicone gel. The weight loss at 200 °C was less than that of the EMC, and changes in physical properties, which are important for mold compounds, were also small, indicating excellent heat resistance. Therefore, a liquid mold compound containing maleimide resin is likely to be suitable as a mold compound for power semiconductor devices operating at 200 °C.

Reagent-Controlled Regioselective Intramolecular [2+2] Cycloaddition between Vinylsilanes and Allenes.

This paper provides the first report of the intramolecular [2+2] cycloaddition of vinylsilane. The [2+2] cycloaddition of allenes is a useful reaction that can synthesize cyclobutanes. However, no previous works have attempted to control the regioselectivity between the two double bonds of allenes only by changing the reaction conditions, although there have been some reports of the regioselective [2+2] cycloaddition of allenes by changing the substrate. In this study, we have succeeded in controlling intramolecular [2+2] cycloaddition reactions at the proximal and distal positions of allenes simply by changing the reaction conditions. We found that the atomic radius of silicon is very important for perfect control of the reaction's sites. The structures of all key compounds were determined by the crystal sponge method which could identify the structures of liquid compounds.

Cancer-specific cytotoxicity of Ringer’s acetate solution irradiated by cold atmospheric pressure plasma

Cold atmospheric pressure plasmas are promising medical tools that can assist in cancer treatment. While the medical pathology mechanism is substantially understood, knowledge of the contribution of reactive species formed in plasma and the mode of activation of biochemical pathways is insufficient. Herein, we present a concept involving antitumoral plasma-activated organics, which is envisaged to increase cytotoxicity levels against cancer cells. Ringer′s acetate solution was irradiated by low-temperature plasma at atmospheric pressure and possible reaction pathways of the compound generation are presented. The chemical compounds formed by plasma treatment and their effects on non-tumorigenic breast epithelial cells (MCF-10A) and breast cancer cells (MCF-7) were investigated. The cell viability results have shown that plasma-derived compounds have both, stimulatory and inhibitory effects on cell viability, depending on the concentration of the generated compounds in the irradiated liquids. Previous studies have shown that oxidative stresses involving reactive oxygen and nitrogen species (RONS) can be used to kill cancer cells. Hence, while RONS offers promising first-step killing effects, cell viability results have shown that plasma-derived compounds, such as acetic anhydride and ethyl acetate, have the potential to play important roles in plasma-based cancer therapy.

Experimental investigation on fracture characteristics by liquid nitrogen compound fracturing in coal

The stimulation efficiency of hydraulic fracturing in coalbed methane (CBM) reservoir are low due to high filtration. In this study, a new compound fracturing method is proposed to improve the CBM reservoir fracturing efficiency combining the advantages of liquid nitrogen (LN2) fracturing and hydraulic fracturing. The compound fracturing starts from LN2 fracturing forming complex fractures and non-filtration zones, follows by injecting nitrogen gas (N2) to displace LN2 near the borehole into the fracture tips and prevent subsequent sand-carrying fluids from freezing in the borehole, and finishes by using sand-fluid mixtures carrying proppant into the frozen coal seam. To test the feasibility, fracturing experiments were conducted to investigate the performances of LN2 compound fracturing. The lab results show that LN2 compound fracturing can create more complex and highly conductive fracture networks than water fracturing and pure LN2 fracturing. Compared with LN2 fracturing, the average fracture aperture, fractures number, and total fracture volume induced by compound fracturing increased by 28%, 10%, and 34%, respectively. Compared with water fracturing, the fractures number, and total fracture volume induced by compound fracturing increased by 55% and 42%, respectively. The reason for the improved conductivity as follows: in the pad stage of the compound fracturing, coal is fractured by LN2 with low viscosity and low temperature, forming a large number of small-scale fractures. In the slurry stage, coal is fractured by water, which further activates the small-scale fractures, increasing the number and aperture of fractures. The key findings obtained in this work is the proposed LN2 compound fracturing method that helps sustainable development of CBM resources in an efficient and environmentally friendly way.

Enhanced selectivity for acidic contaminants in drinking water: From suspect screening to toxicity prediction

A novel analytical workflow for suspect screening of organic acidic contaminants in drinking water is presented, featuring selective extraction by silica-based strong anion-exchange solid-phase extraction, mixed-mode liquid chromatography-high resolution accurate mass spectrometry (LC-HRMS), peak detection, feature reduction and compound identification. The novel use of an ammonium bicarbonate-based elution solvent extended strong anion-exchange solid-phase extraction applicability to LC-HRMS of strong acids. This approach performed with consistently higher recovery and repeatability (88 ± 7 % at 500 ng L-1), improved selectivity and lower matrix interference (mean = 12 %) over a generic mixed-mode weak anion exchange SPE method. In addition, a novel filter for reducing full-scan features from fulvic and humic acids was successfully introduced, reducing workload and potential for false positives. The workflow was then applied to 10 London municipal drinking water samples, revealing the presence of 22 confirmed and 37 tentatively identified substances. Several poorly investigated and potentially harmful compounds were found which included halogenated hydroxy-cyclopentene-diones and dibromomethanesulfonic acid. Some of these compounds have been reported as mutagenic in test systems and thus their presence here requires further investigation. Overall, this approach demonstrated that employing selective extraction improved detection and helped shortlist suspects and potentially toxic chemical contaminants with higher confidence.

Elevated bacterial endospores associated with thermogenic hydrocarbon seeps in deep sea sediments

Endospore distributions in marine sediments are influenced by geological conduits providing routes for subsurface to surface microbial dispersal. To examine this phenomenon in more detail, endospore abundance was determined by quantifying dipicolinic acid (DPA) in 16 deep sea sediment cores from hydrocarbon prospective areas in the NW Atlantic Ocean. DPA concentrations were compared with measurements of over 250 different gaseous and liquid hydrocarbon compounds used to assess for the presence of thermogenic hydrocarbons. This revealed significantly higher levels of endospores at hydrocarbon seep sites than at most hydrocarbon-negative sites. In one exceptional case, a hydrocarbon-negative core in close proximity to adjacent thermogenic seep sites exhibited high endospore abundance, indicating either deposition of endospores emitted from the subsurface via nearby seepage, or alternatively a historical thermogenic hydrocarbon seep where hydrocarbons can no longer be detected by standard geochemistry approaches. This work expands the application of DPA as a proxy for quantifying dormant endospore biogeography of both recent and paleoenvironmental hydrocarbon seep sites.

Changes in Selected Organic and Inorganic Compounds in the Hydrothermal Carbonization Process Liquid While in Storage.

Although many studies have investigated the hydrothermal transformation of feedstock biomass, little is known about the stability of the compounds present in the process liquid after the carbonization process is completed. The physicochemical characteristics of hydrothermal carbonization (HTC) liquid products may change over storage time, diminishing the amount of desired products or producing unwanted contaminants. These changes may restrict the use of HTC liquid products. Here, we investigate the effect of storage temperature (20, 4, and -18 °C) and time (weeks 1-12) on structural and compositional changes of selected organic compounds and physicochemical characteristics of the process liquid from the HTC of digested cow manure. ANOVA showed that the storage time has a significant effect on the concentrations of almost all of the selected organic compounds, except acetic acid. Considerable changes in the composition of the process liquid took place at all studied temperatures, including deep freezing at -18 °C. Prominent is the polymerization of aromatic compounds with the formation of precipitates, which settle over time. This, in turn, influences the inorganic compounds present in the liquid phase by chelating or selectively adsorbing them. The implications of these results on the further processing of the process liquid for various applications are discussed.

Experiment and Molecular Mechanism of Two Chlorinated Volatile Organic Compounds in Ionic Liquids

The structure–property relationship between ionic liquids (ILs) and two chlorinated volatile organic compounds (CVOCs), dichloromethane (DCM) and 1,2-dichloroethane (DCE), was systematically investigated. The suitable IL was screened using the COSMO-RS model, and 1-ethyl-3-methylimidazolium acetate [EMIM][Ac] was considered the optimal absorbent to capture the two CVOCs. The vapor–liquid equilibrium experiment demonstrates that the addition of the IL significantly reduces the vapor pressures of the IL + DCM (or DCE) systems. The structure of ILs on the absorption performance was investigated by absorption capacity experiments. Then, the absorption mechanism was investigated through QC calculations and wavefunction analysis. The consistency between the experiments and the molecular mechanism reveals that the formation of the hydrogen bond between the IL and CVOC enhances the absorption process.