Styrene Vapor Research Articles

Induced π–complexation properties of smectites impregnated by Ni, Cu and Ag transition metals: The highly efficient styrene uptake

Two natural smectite minerals (montmorillonite and beidellite) differing in structural charge location were impregnated with varying amounts of transition metals: Ni(II), Cu(I) or Ag(I). The modification aimed to increase the affinity of the minerals towards styrene vapors. The structure, texture, chemical composition and surface chemistry of the materials were studied by XRD, FTIR, Raman, N2 adsorption/desorption, XRF and XPS. The experiments examined the influence of the starting smectite and the type of introduced metal on styrene adsorption efficiency. The styrene uptake mechanisms were investigated through solid state analysis and supported by DFT calculations. The study demonstrated that the small content of introduced metals (<2% wt.) substantially increased styrene uptake (∼200–350% wt.) surpassing values reported for surfactant-intercalated smectites (∼40–80% wt.) and activated carbons (∼30% wt.). This enhancement was attributed to the π-complexation between dispersed d-block metals and π-electron-rich styrene molecules, subsequently leading to polystyrene formation. The DFT calculations were consistent with experimental findings, indicating a higher affinity of the raw beidellite towards styrene than the raw montmorillonite connected to the charge location. Moreover, the observed trends in calculated adsorption energies and lengths of weak hydrogen bonds allowed to explain a significant adsorption increase observed for the Ni- and Cu-impregnated montmorillonite-based materials.

Evaluating the photocatalytic performance of MOF coated on glass for degradation of gaseous styrene under visible light

Styrene is a volatile organic compound with various applications, especially in the plastics and paint industries. Exposure to it leads to symptoms such as weakness, suppression of the central nervous system, and nausea, and prolonged exposure to it increases the risk of cancer. Its removal from the air is a topic that researchers have considered. Various methods such as absorption, membrane separation, thermal and catalytic oxidation, biofiltration have been used to remove these compounds. The disadvantages of these compounds include the need for high energy, production of secondary pollutants, large space, providing environmental conditions (temperature and humidity) and long time. The photocatalyst process is considered as an advanced process due to the production of low and safe secondary pollutants. MOFs are nanoparticles with unique photocatalytic properties that convert organic pollutants into water and carbon dioxide under light irradiation and in environmental conditions, which prevent the production of secondary pollutants. The present study aimed to investigate the efficiency of MIL100 (Fe) nanoparticles coated on glass in removing styrene vapor from the air. Surface morphology, crystal structure, pore size, functional groups, and chemical composition of the catalyst were analyzed by SEM, XRD, BET, FTIR, and EDX analysis. The effect of parameters such as initial pollutant concentration, temperature, time, relative humidity, and nanoparticle concentration was evaluated as effective parameters in the removal process. Based on the results, MIL100 (Fe) 0.6 g/l with an 89% removal rate had the best performance for styrene removal. Due to its optimal removal efficiency, it can be used to degrade other air pollutants.

Increased styrene vapor removal and power production by adding silicone oil to microbial fuel cell-based trickling filter

This study increases the mass transfer of hydrophobic contaminants in a microbial fuel cell-based trickling filter (MFC/TF) by adding non-aqueous phase liquid. The removal efficiency, mineralization efficiency and elimination capacity of styrene are respectively increased by 1.56 times, 1.86 times and 1.52 times, the power density is increased by 2.6 times and the internal resistance is reduced by approximately 22% after adding 10% silicone oil to the MFC/TF. This is mainly attributed to a decrease in the internal resistance after adding silicone oil, which increases electron transfer on the surface of the auxiliary anode packing and increases the number of electricity-producing bacteria. Adding 10% silicone oil to the MFC/TF increases the number of degrading bacteria and electricity-generating bacteria in the MFC/TF by 2.3–2.5 times. The performance of the MFC/TF using 10% silicone oil is significantly increased because there is increased mass transfer of styrene in the MFC/TF and increased power generation.

Efficient Eu3+-Integrated UiO-66 Probe for Ratiometric Fluorescence Sensing of Styrene and Cyclohexanone

The development of probes with sensitive and prompt detection of volatile organic compounds (VOCs) is of great importance for protecting human health and public security. Herein, we successfully prepared a series of bimetallic lanthanide metal-organic framework (Eu/Zr-UiO-66) by incorporating Eu3+ for fluorescence sensing of VOCs (especially styrene and cyclohexanone) using a one-pot method. Based on the multiple fluorescence signal responses of Eu/Zr-UiO-66 toward styrene and cyclohexanone, a ratiometric fluorescence probe using (I617/I320) and (I617/I330) as output signals was developed to recognize styrene and cyclohexanone, respectively. Benefitting from the multiple fluorescence response, the limits of detection (LODs) of Eu/Zr-UiO-66 (1:9) for styrene and cyclohexanone were 1.5 and 2.5 ppm, respectively. These are among the lowest reported levels for MOF-based sensors, and this is the first known material for fluorescence sensing of cyclohexanone. Fluorescence quenching by styrene was mainly owing to the large electronegativity of styrene and fluorescence resonance energy transfer (FRET). However, FRET was accounted for fluorescence quenching by cyclohexanone. Moreover, Eu/Zr-UiO-66 (1:9) exhibited good anti-interference ability and recycling performance for styrene and cyclohexanone. More importantly, the visual recognition of styrene and EB vapor can be directly realized with the naked eyes using Eu/Zr-UiO-66 (1:9) test strips. This strategy provides a sensitive, selective, and reliable method for the visual sensing of styrene and cyclohexanone.

Catalytic neutralization of gas emissions in the manufacture of pharmaceutical preparations

Environmental protection in the Republic of Uzbekistan with a developed chemical, petrochemical, metallurgical and pharmaceutical industries is an important problem of our time. To solve it, a domestic copper-chromite catalyst “Chemex-203” was previously developed, which was operated for a long time in an energy-saving reversible reactor RKR- 10 in the process of catalytic neutralization of ventilation emissions of highly toxic styrene, toluene and acetone vapors on the territory of the “Hobos-TAPO” joint venture in Tashkent. This paper is devoted to solving a two-sided environmental problem - obtaining copper-chromite catalysts using toxic wastes of local industry for thermal catalytic neutralization of gaseous emissions of volatile organic compounds typical of the pharmaceutical and chemical industries. The conducted studies make it possible to 100% replace imported aluminum hydroxide in the composition of the aluminum-titanium carrier for the copper-chromite catalyst for the complete oxidation of toxic emissions with the intermediate product of the processing of spent alumina adsorbent, including gel-like pseudoboehmite. The resulting catalyst is distinguished by good mechanical strength, chemical and thermal stability and allows highly efficient neutralization of combustible toxic substances in the composition of various gas emissions.

Preparation and physicochemical characterization of deep eutectic solvents and ionic liquids for the potential absorption and biodegradation of styrene vapors

Styrene emissions can be treated by physicochemical, biological, or physicochemical/biological means. Due to its low solubility in water an alternative to eliminate styrene emissions from air is the use of two-phase partitioning bioreactors (TPPBs) which comprised a hydrophobic non-aqueous phase (NAP) which can improve mass transfer of styrene. This study was devoted to prepare and evaluate the main physicochemical characteristics of novel NAPs such as Ionic liquids (ILs), Deep Eutectic Solvents (DESs) and Natural Deep Eutectic Solvents (NADEs) as well as their toxicity and biodegradability to treat styrene vapors. Absorption experiments of styrene showed that the best NAPs were the DESs formed with Tetrabutylammonium bromide and decanoic acid and the ILs [C6mim][FAP], [C4mim] [NTf2] and [C4mim] [PF6], since they presented a styrene partition coefficient between 0.0015 and 0.0041. Finally, the IL [C6mim][FAP] was used as a NAP in a TPPB batch process given its high styrene affinity, low solubility in water and non-biodegradability; styrene mineralization was three times higher in the TPPB compared with the control. ILs are potential adjuvant phases in biological degradation systems, as well as other solvents like DESs and NADESs.

Aggregation-Induced Luminescence Based UiO-66: Highly Selective Fast-Response Styrene Detection

One of the main pollutants in indoor air is volatile organic compounds (VOCs), which can cause great harm to human health. So the development of a VOC detection technology is of great significance. In this work, a tetraphenylethylene-functionalized UiO-66 based on aggregation-induced emission was successfully prepared. The UiO-66-TBPE structure exhibits the characteristic blue emission of TBPE ligands under UV excitation and can be used as a luminescence sensor for fast and efficient detection of VOCs. More importantly, UiO-66-TBPE has a high fluorescence sensing selectivity in p-xylene and styrene vapor. To further improve the practical performance, we combined UiO-66-TBPE with the polymer polyacrylate (PA) to obtain a flexible hybrid membrane with fast detection performance for styrene vapor within the 30 s. The deeper sensing mechanism of p-xylene and styrene inducing different fluorescence enhancement and fluorescence quenching is explained by a combination of modern characterization techniques and computer simulation. Finally, we applied UiO-66-TBPE/PA to leather and still maintained a good sensing performance. It provides a potential way for the application of fluorescent metal-organic frameworks (MOFs) to detect VOCs in daily life.

Performance evaluation of fungal biotrickling filter for styrene destruction: Experimental and artificial neural networks modeling

Removal of styrene vapors was investigated using a fungi-cultured biotrickling filter (BTF) in the presence of rhamnolipid. Evaluations at empty bed residence times (EBRTs) of 90, 60, and 30 s and inlet loading rates (LRs) ranging from 25.5 to 186.1 g m−3 h−1 were conducted. The maximum elimination capacity (EC) of 173.7 g m−3 h−1 was obtained at an inlet LR of 186.1 g m−3 h−1 at 90 s EBRT. Reducing the EBRT to 60 and 30 s resulted in decline of removal efficiency (RE). The performance of BTF was modeled using artificial neural network (ANN) to predict styrene RE using measurable inputs, inlet LR, EBRT, and pressure drop. The model performance was assessed by mean square error and overall coefficient of correlation. The influence of different input parameters on the output was analyzed using casual index. Styrene removal was positively influenced by the increase in EBRTs, negatively impacted by its inlet LRs, while pressure drop had a negligible effect. The BTF was then exposed to intermittent loading phases by varying operational conditions during the non-loading periods. The results from this study confirmed that rhamnolipids could enhance the BTF performance for handling transient load variations at unsteady-state conditions.

Polythiophene based fluorimetric insight into minute styrene concentration in solution and gas phase

Water immiscible organic solvents dispersed in aqueous phase raise concerns due to persistence in environment and high toxicity. Fast and operation-simple approaches to assess their contents outside specialized laboratories are required. In this work an original approach allowing quantification of minute amounts of styrene present in solution or in gas phase is proposed. Polythiophene - poly[3-(ethyl-6-hexanoate)thiophene-2,5-diyl] (PeHT) - nanoparticles were applied as probes, offering an increase of emission intensity upon the rise of styrene contents in the sample. The response mechanism is based on the interaction of the polymer dye with analyte; at lower concentrations, the increase of emission at wavelengths typical for nanoparticles emission suggests interactions of the analyte with polymer chains in nanostructural form and offers selectivity. On the other hand, with increasing styrene contents in solution, polythiophene tends to form nano-dispersion droplets in the analyte resulting in appearance of emission peak characteristic for solvent dispersed polymer. A linear dependence of emission intensity on styrene concentration in solution was observed within the range from 0 to 200 ppm. The proposed approach benefits from full reversibility of sensors, upon spontaneous evaporation of styrene from solution. Finally, the nanoparticle suspension allows to detect the presence of styrene also in the vapor phase due to its solubilization in water (Henry's Law). Emission changes were observed in case of 0–2100 ppm of styrene vapor in the probe headspace, corresponding to 0–80 ppm styrene in solution. For the sake of comparison another polythiophene derivative, poly(3-octylthiophene-2,5-diyl) (POT), was investigated showing no changes in fluorescence emission spectra in the presence of styrene up to 200 ppm.

Styrene bioconversion by Pseudomonas putida utilizing a non‐aqueous phase for polyhydroxyalkanoate production

AbstractBACKGROUNDStyrene is a volatile organic compound used extensively worldwide. It is known to cause serious adverse effects on human health and the environment. The main limitation in the biological treatment of styrene is its low solubility. An alternative is the use of partitioning bioreactors (TPPB) which can improve mass transfer of styrene by addition of a hydrophobic non‐aqueous phase (NAP). This study explored silicone oil and an ionic liquid as NAPs in a TPPB to degrade styrene vapors using Pseudomonas putida S12. Lastly, the production of polyhydroxyalkanoates (PHA) was evaluated.RESULTSThe NAPs were characterized in terms of biodegradability, toxicity and styrene partition coefficient (H). Results showed that styrene was 7.5 times more absorbed by the ionic liquid/aqueous phase mixture (H = 0.0035) than by the silicone oil/aqueous phase mixture (H = 0.0179) at 28 °C. Silicone oil and ionic liquid were non‐biodegradable by P. putida S12. However, the ionic liquid was inhibitory and toxic for P. putida S12 in contrast to silicone oil. Thus, the selected phase for the TPPB process was silicone oil. Silicone oil assays reached a 98% styrene removal efficiency faster (4 h) than the control (8 h). This finding was reflected in a faster production of the same amount of PHA in the presence of silicone oil.CONCLUSIONSThe production of PHA was enhanced by the addition of silicone oil at 5% (v/v) in a TPPB batch process treating styrene vapors. © 2021 Society of Chemical Industry (SCI).

Emergency responder and public health considerations for plastic sewer lining chemical waste exposures in indoor environments

The cured‐in‐place pipe (CIPP) manufacturing process is used to repair buried pipes, and its waste commonly discharged into the air can enter nearby buildings. Exposure can prompt illness and the need for medical care. A mass balance model was applied to estimate indoor styrene concentrations due to intrusion of CIPP emissions through plumbing under different bathroom ventilation conditions. To better understand building contamination and recommend emergency response actions, calculations to estimate chemical intrusion through plumbing were developed. Field reports and study calculations showed that contractor-applied external pressures during plastic manufacture have and can displace plumbing trap water seals. Modeled styrene vapor concentrations that entered the building (1, 300, 1000 ppm) were similar to those measured at CIPP worksites. Modeling revealed that in some cases, bathroom exhaust fan operation during a CIPP project may increase indoor styrene concentrations due to enhanced entrainment of styrene-laden air from the sink and toilet. However, styrene concentrations decreased with increasing air leakage across the bathroom door due to reduced suction from the plumbing system. CIPP waste discharge should be treated as a hazardous material release and can pose a threat to human health. Immediate building evacuation, respiratory protection, provision of medical assistance, source elimination, and building decontamination are recommended.

Sensing Behavior of Metal-Free Porphyrin and Zinc Phthalocyanine Thin Film towards Xylene-Styrene and HCl Vapors in Planar Optical Waveguide.

The sensing behavior of a thin film composed of metal-free 5, 10, 15, 20-tetrakis (p-hydroxy phenyl) porphyrin and zinc phthalocyanine complex towards m-xylene, styrene, and HCl vapors in a homemade planar optical waveguide (POWG), was studied at room temperature. The thin film was deposited on the surface of potassium ion-exchanged glass substrate, using vacuum spin-coating method, and a semiconductor laser light (532 nm) as the guiding light. Opto-chemical changes of the film exposing with hydrochloric gas, m-xylene, and styrene vapor, were analyzed firstly with UV-Vis spectroscopy. The fabricated POWG shows good correlation between gas exposure response and absorbance change within the gas concentration range 10–1500 ppm. The limit of detection calculated from the logarithmic calibration curve was proved to be 11.47, 21.08, and 14.07 ppm, for HCl gas, m-xylene, and styrene vapors, respectively. It is interesting to find that the film can be recovered to the initial state with trimethylamine vapors after m-xylene, styrene exposures as well as HCl exposure. The gas-film interaction mechanism was discussed considering protonation and π-π stacking with planar aromatic analyte molecules.

Styrene Detection in Water By Polythiophene Nanoparticles Suspension

Introduction The versatility of fluorescent reporters makes them adaptable to the detection of different chemicals. [1] Most fluorescent systems work in quenching mode, namely the sensor signal consists in a reduction of the emission; less frequent is the case of sensing molecules where the fluorescence is activated by the interaction. Recently, this behavior has been demonstrated in optical fluorescent reporters made of Poly(3-octylthiophene) nanoparticles have been recently reported. [2] In this work we utilized a similar approach to detect styrene in water. Styrene is an aromatic hydrocarbon, used for the preparation of polystyrene, one of the most popular polymers, widely used in many industrial processes. Here we investigated the feasibility of polythiophene, Poly[3-(Ethyl-6-hexanoate)thiophene-2,5-diyl], nanoparticles stabilized in aqueous medium by the presence of poly-vinyl alcohol (PVA). Actually, these nanoparticles are able to sense the presence of styrene by increasing the fluorescence emission. The sensor is enough sensitive to detect the styrene dissolved in water solution from the gaseous phase. Thus, this system can be used to measure not only styrene contamination in water, but also styrene contamination in air. This latter event threats the health of workers in several industrial processes.Saturated styrene vapors were mixed with nitrogen by mass flow controllers and then fluxed over the water solutions, obtaining different concentrations of styrene in the liquid phase (following the Henry’s law). This latter case enables to reach low concentrations in water. Results shows a high sensitivity to styrene. The selectivity has been tested comparing the response to an alcohol (ethanol) and a chlorinated solvent (chloroform). Experimental Synthesis of nanoparticles was performed using typical procedure for polythiophene nanosystems [2]; 100 mL of PT solution in THF (10 mg/ mL) was added to 1 mL 1 % w/w PVA on a stirrer. The THF evaporation within 5 min was resulting in nanoparticle formation. TEM images of PT nanoparticles are reported in Figure 1.Figure 2 shows the characterization setup. Styrene saturated vapors were diluted with nitrogen gas to achieve a desired concentration and fluxed in the headspace of PT suspended in water. Saturated vapor pressures were calculated by Antoine equation, whereas air-water coefficient partition was used to calculated the concentration in water due to the solubilization. Fluorescence changes were recorded by RF-1501 fluorimeter. Results Figure 3 shows the emission spectra of PT nanoparticles in water excited at 490 nm. Styrene in water elicits the increase of emission. A peak at 585 nm in the emission spectra is observed under styrene exposure. At concentrations in air above 40 ppm, a second peak at 620 nm is observed. The intensity at 585 nm is barely linear with the concentration in air (Figure 4). Due to the emergence of the additional peak at 620 nm, the peak at 585 becomes broader, and this behavior affects the linearity of the sensor response. A proper multicomponent analysis of spectral data provides a better estimation of the styrene concentration. The linear fit of Figure 4 returns a sensitivity of about 3 ppm-1 respect to styrene in air. The sensitivity has also been measured respect to an alcohol (ethanol) and a chlorinated solvent (chloroform). Figure 5 shows that sensitivity to styrene is about an order of magnitude larger respect to chloroform and three orders of magnitude respect to ethanol. References Paolesse R, Monti D, Dini F, Di Natale C. Fluorescence based sensor arrays, Topics in Current Chemistry, 2011; 300, 139-174Woźnica, E., Maksymiuk, K., & Michalska, A. Polyacrylate microspheres for tunable fluorimetric zinc ions sensor. Analytical chemistry 86.1 (2013): 411-418. Figure 1

Comparative Assessment of Carcinogenic Risk of Styrene Vapors Using Two Semi-Quantitative Methods in a Petrochemical Industry

Background: Styrene is one of the chemicals used in industries, especially the petrochemical industry, which affects health. Singaporean methods and the WHO use different parameters to assess the carcinogenic risk of the substance. Therefore, this study aimed to compare the level of carcinogenic risk due to exposure to styrene using the Singapore Department of Occupational Health with the risk levels provided using the WHO to achieve high-reliability results.&#x0D; Methods: In this study, 150 air samples were collected from the respiratory area of 50 employees by NIOSH1501 method, after identification of styrene emission units and preparation of identical exposure groups. The samples were analyzed by Varian-cp3800 gas chromatograph. Finally, the risk of styrene's health effects on petrochemical staff was calculated using the method of the Singapore Department of Occupational Health, and the results were compared with the risk levels of styrene presented by WHO.&#x0D; Results: The carcinogenicity of styrene was higher in polybutadiene latex (PBL) (2.3 ) and the fire department (1.3 ) in comparison with the other units. The World Health Organization-defined risk levels predicted 22% of staff to be a "definitive" carcinogenic risk. While the Singapore Department of Occupational Health approached a "low" risk rating.&#x0D; Conclusion: A "low" risk rating was obtained through the Singapore Department of Occupational Health. But the WHO method for 30 years of exposure to styrene predicted "probable risk" and "definitive risk." This showed a high difference in the results of the two semi-quantitative methods used.

VIZAG GAS LEAK- A CASE STUDY ON THE UNCONTROLLED STYRENE VAPOUR RELEASE FOR THE FIRST TIME IN INDIA

Industrial emergencies involving hazardous chemicals are not uncommon in India. During the last several decades there has been a growing awareness of the expanding risks and consequences of major industrial disasters. Industrial hazards can occur at any stage in the production process, including extraction, processing, manufacture, transportation, storage, use, and disposal. Losses generally involve the release of damaging substances (e.g. chemicals, radioacvity) or damaging levels of energy from industrial facilities or equipment into surrounding environments. This usually occurs in the form of explosions, fires, spills, leaks, or wastes. In a recent occurrence on the wee hours of 7th May 2020, an accident of uncontrolled release of Styrene vapor occurred at LG Polymers India Pvt. Ltd. (LG Polymers) in RR Venkatapuram Village, Visakhapatnam from one of the Styrene storage tanks. The hazardous Styrene vapors spread beyond the factory premises, affecting the populace of five villages / habitations. The officials from the District administration along with Police Department, GVMC, National Disaster Response Force (NDRF) and local people rushed to the spot for rescue operations. However, the grave accident led to 12 citizens losing their lives and 585 citizens being hospitalized. In this regard let’s take a brief look into the causes of the accident which led to this grave mishap. KEYWORDS: Vizag gas leak, styrene vapour, MSIHC 1989, Pre-Startup Safety Review (PSSR), Hazardous Material Information System (HMIS), Process safety management.

A new synthesis approach for proton exchange membranes based on ultra‐high‐molecular‐weight polyethylene

AbstractA new approach for gas‐phase modification of ultra‐high‐molecular‐weight polyethylene (UHMWPE) film for synthesis of proton exchange membranes (PEMs) has been successfully realized. First, the membrane precursors have been prepared by soaking the films in a monomers/AIBN solution followed by their modification with polystyrene (PS) in styrene vapor at 110°C. The developed method is characterized by high efficiency, simplicity, and ecological purity. The modified UHMWPE films containing up to 60 wt% of PS have been obtained. Then, PEMs were prepared by sulfonation of these precursors. According to energy‐dispersive X‐ray spectroscopy of the sulfonated samples, almost uniform distribution of PS through the film thickness was observed. The membranes with an ion exchange capacity up to 2.7 mmol/g and proton conductivity up to 60 mS/cm (water, 25°C) were obtained. Comparative tests of the obtained UHMWPE‐sulfonated PS and commercial Nafion‐115 membranes in a hydrogen–air fuel cell have been carried out. It has been shown that the cell with the synthesized membranes exhibits better performance than that with Nafion‐115.

Styrene Detection in Water By Polythiophene Nanoparticles Suspension

Introduction The versatility of fluorescent reporters makes them adaptable to the detection of different chemicals. [1] Most fluorescent systems work in quenching mode, namely the sensor signal consists in a reduction of the emission; less frequent is the case of sensing molecules where the fluorescence is activated by the interaction. Recently, this behavior has been demonstrated in optical fluorescent reporters made of Poly(3-octylthiophene) nanoparticles have been recently reported. [2] In this work we utilized a similar approach to detect styrene in water. Styrene is an aromatic hydrocarbon, used for the preparation of polystyrene, one of the most popular polymers, widely used in many industrial processes. Here we investigated the feasibility of Poly[3-(Ethyl-6-hexanoate)thiophene-2,5-diyl], hereinafter referred to as either polythiophene or PT, nanoparticles stabilized in aqueous medium by the presence of poly-vinyl alcohol (PVA). Actually, these nanoparticles are able to sense the presence of styrene by increasing the fluorescence emission. The sensor is enough sensitive to detect the styrene dissolved in water solution from the gaseous phase. Thus, this system can be used to measure not only styrene contamination in water, but also styrene contamination in air. This latter event threats the health of workers in several industrial processes.Saturated styrene vapors were mixed with nitrogen by mass flow controllers and then fluxed over the water solutions, obtaining different concentrations of styrene in the liquid phase (following the Henry’s law). This latter case enables to reach low concentrations in water. Results shows a high sensitivity to styrene. The selectivity has been tested comparing the response to an alcohol (ethanol) and a chlorinated solvent (chloroform). Experimental Synthesis of nanoparticles was performed using typical procedure for polythiophene nanosystems [2]; 100 mL of PT solution in THF (10 mg/ mL) was added to 1 mL 1 % w/w PVA on a stirrer. The THF evaporation within 5 min was resulting in nanoparticle formation. TEM images of PT nanoparticles are reported in Figure 1.Figure 2 shows the characterization setup. Styrene saturated vapors were diluted with nitrogen gas to achieve a desired concentration and fluxed in the headspace of PT suspended in water. Saturated vapor pressures were calculated by Antoine equation, whereas air-water coefficient partition was used to calculated the concentration in water due to the solubilization. Fluorescence changes were recorded by Shimadzu RF-1501 fluorimeter. Results Figure 3 shows the emission spectra of PT nanoparticles in water excited at 490 nm. Styrene in water elicits the increase of emission. A peak at 585 nm in the emission spectra is observed under styrene exposure. At concentrations in air above 40 ppm, a second peak at 620 nm is observed. The intensity at 585 nm is barely linear with the concentration in air (Figure 4). Due to the emergence of the additional peak at 620 nm, the peak at 585 becomes broader, and this behavior affects the linearity of the sensor response. A proper multicomponent analysis of spectral data provides a better estimation of the styrene concentration. The linear fit of Figure 4 returns a sensitivity of about 3 ppm-1 respect to styrene in air. The sensitivity has also been measured respect to an alcohol (ethanol) and a chlorinated solvent (chloroform). Figure 5 shows that sensitivity to styrene is about an order of magnitude larger respect to chloroform and three orders of magnitude respect to ethanol. Acknowledgements. “Financial support from Italy-Poland Canaletto program, project PO19MO08 is gratefully acknowledged.”

The Use of Competitive Reactions for Studying the Process of Unsaturated Organic Compound Vapor Removal from Air by Pulsed Discharge Plasma

We propose using competitive reactions for studying the efficiency of volatile organic compound (VOC) removal from air under the action of pulsed discharge plasma. By introducing a VOC with known parameters into the model vapor mixture, it is possible to determine analogous properties of other compounds using a chromatographic method not possessing high temporal resolution. By the example of a mixture of styrene and methylmethacrylate vapors, it is shown that the relative reactivity of unsaturated compounds in discharge plasma is well correlated with the ratio of their rate constants of reaction with ozone.

Метод конкурирующих реакций в исследовании процессов удаления паров ненасыщенных органических соединений в воздухе под действием плазмы импульсного разряда

To study the efficiency of the removal of vapors of volatile organic compounds from air flows when processed by a plasma of pulsed discharges, a method of competing reactions is proposed. Using a compound with known parameters in the model mixture, it is possible to estimate similar parameters of other compounds using a chromatographic method of analysis that does not have a high temporal resolution. By the example of styrene and methyl methacrylate vapors, it was shown that for unsaturated compounds their relative reactivity in the discharge plasma correlates well with the ratio of the rate constants of their reactions with ozone.

Novel magnetic pillar[5]arene polymer as adsorbent for rapid removal of organic pollutants in water or air

A magnetic pillar[5]arene polymer (M-P5A-P) was prepared for removal of organic pollutants in water and air. M-P5A-P was synthesized by grafting pillar[5]arene polymer on the surface of the cellulose-closed magnetic microparticles. The obtained M-P5A-P was characterized by FT-IR spectroscopy, transmission electron microscope, X-ray diffraction, magnetic hystersis loop analysis, thermo-gravimetric analysis, and energy dispersive X-ray spectrometer. When used as an adsorbent for four different types of organic pollutants (bisphenol A, 1-naphthylamine, propranolol and methylene blue) in water, M-P5A-P presented much higher adsorption ability than magnetic cellulose and fast binding kinetics with the equilibrium time all less than 10 min. Moreover, M-P5A-P can be rapidly separated from solution by a magnet, and it showed good reusability and reproducibility. M-P5A-P was successfully applied to the simultaneously rapid removal of four pollutants (0.1 μg mL−1 for each one) in mixed solution with removal efficiencies of 82.3–99.4% within 5 min. M-P5A-P can also rapidly capture styrene vapor at environmental concentration to a concentration much lower than the limit of the U.S. Occupational Safety and Health Administration within 5 min. Therefore, M-P5A-P can be potentially used as a good adsorbent for simultaneously removing different type of organic pollutants in water or air.