Acetic Acid Vapor Research Articles

Mono and binuclear Pt(II) complexes incorporated with NHC ligands: syntheses, photophysical properties, and acid vapor responses

Three mononuclear complexes (PtL1H, PtL2H, and PtL3H) and one binuclear complex (Pt2L1) have here been prepared using the bis-carbene ligand of 1,3-propylene-bis(1,3-dihydro-3-butyl-2H-imidazol-2-ylidene) and one of three rigid planar ligands of dibenzo[f,h]quinoxaline (L1H2), dibenzo[a,c]phenazine (L2H2), and tribenzo[a,c,i]phenazine (L3H2). These four complexes were fully characterized by nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HRMS), and elemental analyses. Moreover, the two binuclear complexes Pt2L2 and Pt2L3 could not be isolated, but Pt2L3 was isolated and characterized by single-crystal X-ray diffraction (XRD). Complexes PtL1H, PtL2H, and Pt2L1 exhibited phosphorescence in N2-degassed dichloromethane (DCM) solution at 563 nm, 656 nm, and 624 nm, respectively. Also, Pt2L1 exhibited triplet emission at 553 nm in a 2 wt% PMMA film, with the highest Ф of 63 % and τ of 23.8 μs. Moreover, complexes PtL1H and Pt2L1 were deposited on quartz plates to monitor formic acid vapor and acetic acid vapor. The plates that were covered with PtL1H exhibited phosphorescent quenching in both formic acid and acetic acid. However, the plates that were covered with Pt2L1 did only show a prompt response to formic acid, but were not sensitive to acetic acid.

A novel macroporous carboxymethyl chitosan/sodium alginate sponge dressing capable of rapid hemostasis and drug delivery

Carboxymethyl chitosan (CMCS) and sodium alginate (SA), which are excellent polysaccharide-based hemostatic agents, are capable of forming polyelectrolyte complexes (PEC) through electrostatic interactions. However, CMCS/SA PEC sponges prepared by the conventional sol-gel process exhibited slow liquid absorption rate and poor mechanical properties post-swelling. In this work, a novel strategy involving freeze casting followed by acetic acid vapor treatment to induce electrostatic interactions was developed to fabricate novel PEC sponges with varying CMCS/SA mass ratios. Compared to sol-gel process sponge, the novel sponge exhibited a higher density of electrostatic interactions, resulting in denser pore walls that resist re-gelation and swelling according to FTIR, XRD, and SEM analyses. Additionally, the liquid absorption kinetics, as well as compression and tension tests, demonstrated that the novel sponge had significantly improved rapid blood absorption capacity and mechanical properties. Furthermore, in vitro coagulation and drug release studies showed that the novel sponge had a lower blood clotting index and clotting time, along with a slower drug release rate after loading with berberine hydrochloride, showcasing its potential as a rapid hemostatic dressing with controlled drug release capabilities.

Reversible electronic modulation of polydiacetylenes for sensing in dynamic conditions

AbstractPolydiacetylenes (PDAs) are renowned for their exceptional optical properties intricately linked to the polymer conformation, yet they exhibit poor conductivity in their undoped state. Despite this drawback, PDAs have garnered significant interest as sensing materials owing to their ability to undergo colorimetric shifts from blue to red in response to external stimuli. However, the irreversible nature of this transition has limited their utility in dynamic environments. In this study, we augment the sensing capabilities of PDA films beyond their irreversible optical response by inducing a reversible electronic response through conductivity modulation. We investigated polyamine‐substituted PDAs with enriched hydrogen‐bonding interaction sites for the concurrent changes in colorimetry and conductivity upon acetic acid (AA) vapor exposure. Coated on a flexible interdigitated electrode (IDE), we monitor the conductivity change throughout the blue‐to‐red phase transition. Remarkably, AA molecules act as dopants, significantly amplifying the system's conductivity. Although the PDA coating retains its red phase at postdopant removal, the electronic response reverts to its initial state, demonstrating reversibility. This reversible electronic response offers invaluable real‐time insights into the specific triggers within dynamic environments, underscores the adaptability of responsive conjugated polymers, and highlights a promising avenue for their utilization in various sensing and monitoring applications.

Lead(II)-Based Coordination Polymer Exhibiting Reversible Color Switching and Selective CO2 Photoreduction Properties.

Herein, we report a new photofunctional Pb-S-based coordination polymer (CP) with the formula [Pb(ATAT)(OAc)]n (ATAT = 3-amino-5-mercapto-1,2,4-triazole, OAc = acetate, CP1). Apart from its photoactive one-dimensional (1D) (-Pb-S-)n chain, CP1 is also composed of another 1D (-Pb-O-)n chain that originates from the coordination with acetate. The coordinated acetate can be exchanged with water (H2O) or dimethyl sulfoxide (DMSO), leading to the formation of a CP1-H2O or CP1-DMSO structure that exhibits a distinct change in optical properties, including a white-to-yellow color change. The structural transformation of CP1 to CP1-H2O and CP1-DMSO, and its subsequent recovery to the original CP1 structure could be controlled by the presence or absence of acetic acid vapor; the transformation was completely reversible. CP1 absorbed light with wavelengths shorter than 390 nm, with an estimated bandgap of 3.18 eV. Density functional theory calculations indicated that the valence band of CP1 is mainly formed by N and S orbitals originating from the ATAT unit, whereas the conduction band is composed of the Pb orbitals. Even without any modification, such as the incorporation of a molecular catalyst, CP1 reduced CO2 into formate under UV light with >99% selectivity.

Indicator Films Containing Dendrobium Orchid Flower Extract and TiO2 Nanoparticles for Monitoring Fish Fillet Spoilage

This work aimed to study a novel pH indicator film prepared from carboxymethyl cellulose (CMC)/tapioca starch (TS) incorporating Dendrobium orchid flowers and TiO2 nanoparticles for monitoring fish fillet freshness. The films were prepared based on carboxymethyl cellulose (CMC) and tapioca starch (TS) blend (CMC/TS) incorporated with TiO2 nanoparticles and Dendrobium orchid flower (DOF) extract. The result showed that the DOF extract contained peonidin-3,5-O-diglucoside and exhibited distinguishable color changes in different pH buffers. Likewise, the CMC/TS+TiO2+DOF film’s color changed corresponding to the extract. The X-ray diffraction analysis revealed the expansion of the film’s amorphous region, due to the intermolecular interactions. Analyzing scanning electron microscope images showed the effects of TiO2 and DOF extract on the surface morphology of films. The incorporation of TiO2 and DOF extract into the film formulation improved various film properties, such as redness, opacity, tensile strength, and water solubility. For the sensitivity testing, the color of the CMC/TS+TiO2+DOF film responded to ammonia vapor more than acetic acid vapor, suitable for monitoring seafood spoilage behavior. In addition, the application of film for monitoring the freshness of fish fillets was conducted. The CMC/TS+TiO2+DOF film color changed from purple to bluish-purple corresponding to the spoilage of samples. Indicating its potential as an indicator for monitoring fish fillets' freshness.

The room temperature ethanol gas sensors based on MoS2-CuGaO2 composite prepared by hydrothermal method

In this paper, MoS2-CuGaO2 composites were successfully synthesized by hydrothermal method. The composites were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), respectively. The specific surface area and pore size distribution were obtained by N2 adsorption-desorption isotherms. The gas sensing property measurements were conducted. The sensitivity of pure CuGaO2 based gas sensor to 100 ppm acetic acid and benzene vapor was 1.4 at 25oC. The sensitivity of MoS2-CuGaO2 composite (M − 5) was 6.0 towards 100 ppm ethanol vapor at 25oC. And the detection limit of MoS2-CuGaO2 (M − 5) based sensor was 0.1 ppm. The results demonstrated that MoS2 had effect on the selectivity and sensitivity of the MoS2-CuGaO2 composites. M − 5 composite is considered to be promising for ethanol sensing application in room temperature.

Thermal behavior of Sicilian clay-based geopolymers

AbstractGeopolymers have been recently proposed for restoration of built heritage to substitute traditional mortars. Local materials and industrial wastes from the Italian region Sicily showed their potential as low-cost aluminosilicate sources for the preparation of geopolymers. Here, a set of Sicilian clays was studied by Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC), and its mineralogical composition was evaluated by X-ray diffraction (XRD). The raw materials were used to prepare geopolymers by alkaline activation with or without the addition of silicate. The thermal degradation profile of the final materials was studied by TGA and compared with that of the precursors, and the energetics of dehydration were investigated by DSC. Two statistical analyses (made by Principal Component Analysis) were performed on the TG data of raw materials and geopolymers and on the TG data of geopolymers and their mineralogical composition, respectively. The last analysis in particular showed a correlation between the mineralogical composition of the materials and the samples' thermal properties. Additional studies of samples subject to accelerated aging by UV irradiation and exposure to acetic acid vapors highlighted the different effects of these two agents on the samples’ stability. Graphical abstract

Inactivation of Listeria monocytogenes on a laboratory medium and enoki mushrooms using organic acid and essential oil vapors

The aim of this study was to determine the antimicrobial activity of organic acid (OA) and essential oil (EO) vapors against Listeria monocytogenes on a laboratory medium and enoki mushrooms. Among 14 OA and 8 EO vapors tested, 3 OA vapors (acetic, formic, and propionic acid) and 3 EO vapors (cinnamon bark, citronella, and lemongrass) showed relatively strong antilisterial activity. On tryptic soy agar (TSA), all three OA vapors had a minimum inhibitory concentration (MIC) of 12.5 mg/L, while the minimum lethal concentration (MLC) of formic acid vapor was the lowest, at 50 mg/L, followed by acetic acid vapor (200 mg/L) and propionic acid vapor (400 mg/L). The MIC values of lemongrass, cinnamon bark, and citronella EO vapors were 25, 100, and 100 mg/L, respectively. The MLC of lemongrass EO vapor was 100 mg/L and MLCs of other EO vapors were >400 mg/L. Formic acid and lemongrass EO vapors showed a partial synergism on TSA (fractional inhibitory concentration index of 0.7500). For L. monocytogenes inoculated on enoki mushrooms, formic acid vapor at a concentration of ≥50 mg/L, as well as formic acid and lemongrass vapors in combination (1:2 vol ratio) at ≥ 75 mg/L, inactivated L. monocytogenes. These results indicate that formic acid vapor is effective at controlling the growth of L. monocytogenes on enoki mushrooms.

A Polyvinylpyrrolidone Nanofibrous Sensor Doubly Decorated with Mesoporous Graphene to Selectively Detect Acetic Acid Vapors.

An original approach has been proposed for designing a nanofibrous (NF) layer using UV-cured polyvinylpyrrolidone (PVP) as a matrix, incorporating mesoporous graphene carbon (MGC) nanopowder both inside and outside the fibers, creating a sandwich-like structure. This architecture is intended to selectively adsorb and detect acetic acid vapors, which are known to cause health issues in exposed workers. The nanocomposite MGC-PVP-NFs layer was fabricated through electrospinning deposition onto interdigitated microelectrodes (IDEs) and stabilized under UV-light irradiation. To enhance the adhesion of MGC onto the surface of the nanocomposite polymeric fibers, the layer was dipped in a suspension of polyethyleneimine (PEI) and MGC. The resulting structure demonstrated promising electrical and sensing properties, including rapid responses, high sensitivity, good linearity, reversibility, repeatability, and selectivity towards acetic acid vapors. Initial testing was conducted in a laboratory using a bench electrometer, followed by validation in a portable sensing device based on consumer electronic components (by ARDUINO®). This portable system was designed to provide a compact, cost-effective solution with high sensing capabilities. Under room temperature and ambient air conditions, both laboratory and portable tests exhibited favorable linear responses, with detection limits of 0.16 and 1 ppm, respectively.

Characterization of Lactoperoxidase (LPO) Enzyme Thin Films for Volatile Organic Compound (VOC) Sensing

Spin-coated thin films of lactoperoxidase enzyme (LPO) were used on conjunction with the bio-composite (chitosan–gelatin), glutaraldehyde and cysteine as first-layers to characterize the interactions on the sensing characteristics. The prospect of tuning these three under-layers is to investigate the change of active vapor binding sites of LPO film after inter-layer interactions. Initially, spin-coated thin film properties of three under-layers and LPO are investigated by reporting deposited mass and layer thickness using the quartz crystal microbalance (QCM) frequency change. LPO spin-coated films with different under-layers are exposed to formic acid, acetic acid, chloroform, acetone and ethyl acetate vapors. The response characteristics of LPO films are investigated via QCM using time dependence frequency recording. LPO films are sensitive to those five vapors and the chemical and the physical properties of the analytes affect the sensitivity and the response rate. The results showed that the structural changes in the thin film affect the number of active binding sites of sensitive layer and thus the sensor response can be enhanced.

Performance of Polyaniline Thin Film as a Functional Material of Acid Vapor Sensors

Polyaniline (PANI) is a conductive polymer that can be produced by the electrodeposition process. The purpose of this research is to evaluate the performance of PANI sensors on hydrochloric acid (HCl) and acetic acid (CH3COOH) vapor using a scan rate of 100 mV/s and ten cycles, a thin PANI layer was created on the surface of the ITO substrate. The PANI spectroscopic test results before and after CH3COOH vapor exposure revealed no differences and remained within the PANI functional group range. A four-point probe (FPP) test was performed to evaluate the sensing performance of the PANI thin film against analyte gas. The results of recovery time, response time, and sensitivity tended to increase as analyte concentration increased. The quickest CH3COOH sensing (1 ppm) has a reaction time of 29.7 seconds, a recovery time of 21.9 seconds, and a sensitivity of 5.11%. The greatest CH3COOH sensing (10 ppm) resulted in a reaction time of 50.3 seconds, a recovery time of 39.7 seconds, and a sensitivity of 13.64%. The reaction time for the lowest HCl sensing (1 ppm) was 42.6 s, the recovery time was 32.4 s, and the sensitivity was 7.82%. The greatest level of CH3COOH sensing (10 ppm) resulted in a response time of 60.6 s, a recovery time of 55.3 s, and a sensitivity of 16.31%. As a result, the PANI thin film is a functional material for acid gas sensors.

Flammability and Acetic Acid Emissions from Acetylated Wood under Well-Ventilated Burning Conditions

Acetylation is a type of commercial wood modification used to enhance the durability of wood. Despite its adoption, especially in outdoor environments, there are mixed data on how acetylation affects the combustion of wood. This paper evaluates the differences in acetylated and untreated wood using a cone calorimeter in combination with Fourier Transform Infrared Spectroscopy (FTIR) to look for acetic acid vapors in the combustion gases. Two thicknesses of acetylated pine boards were tested and compared against an untreated board from the same genus. No differences were observed between the peak heat release between the acetylated and untreated boards. Likewise, there were no trends in the time to ignition between the acetylated wood and the control group. Differences were observed however in the chemical composition of the combustion products. An increase in acetic acid in the products of combustion was observed for the acetylated samples that corresponded with the peak heat release of the sample.

Eye and airway symptoms in hospital staff exposed to a product containing hydrogen peroxide, peracetic acid, and acetic acid.

Sporicidal products containing hydrogen peroxide (HP),peracetic acid (PAA),and acetic acid (AA)are used widely in multiple industries, including healthcare. Despite widespread use in healthcare, few studies have assessed associations between exposures to HP, PAA, and AA, and work-related symptoms in these settings. In 2018, we performed a health and exposure assessment at a hospital where a sporicidal product consisting of HP, PAA, and AA, was used as the primary cleaner on hospital surfaces. We collected 56 personal and mobile air samples for HP, PAA, and AA on participants while they performed their regular cleaning duties; collected area samples for HP (n = 28), PAA (n = 28), and AA (n = 70) in multiple hospital locations where cleaning was performed; and administered a postshift survey to assess eye, skin, and upper and lower airway symptoms that occurred cross-shift or in the previous 4 weeks. Full-shift exposure levels for HP (range: <3-559 ppb), PAA (range: <0.2-8 ppb), and AA (range: <5-915 ppb) were all below USoccupational exposure limits. We observed positive associations (p < 0.05) between shift, departmental average, and departmental 95th percentile exposures to HP, PAA, and AA vapors, and work-related acute (cross-shift) and chronic (previous 4 weeks) eye, upper airway, and lower airway symptoms after adjusting for age, gender, smoking status, use of other cleaning products containing sensitizers and irritants, allergic status, and stress. Our observations of work-related upper and lower airway symptoms among hospital workers exposed to vapors from a sporicidal product containing HP, PAA, and AA indicate a need for a combination of engineering, administrative, and PPE controls to reduce exposure. Additionally, alternative nonchemical disinfection technologies should be further investigated as a means to simultaneously reduce healthcare workers' exposure to disinfectants while also minimizing costly healthcare-acquired infections.

Comparative Study of Corrosion Activity of Bright and Matte Nickel Coatings in Solutions and Vapor of Acetic Acid

Comparative Study of Corrosion Activity of Bright and Matte Nickel Coatings in Solutions and Vapor of Acetic Acid

Poly (lactic acid)-based pH responsive membrane combined with chitosan and alizarin for food packaging

A poly (lactic acid) (PLA) -based functional partition composite membrane (PLA/CA) containing chitosan (CS) and alizarin (AL) was designed by solution casting method. The PLA/CA membrane contains the antibacterial zone of the edge part (PLA/CS) and the pH response detection zone of the central part (PLA/AL). At the same time, the environmentally friendly plasticizer tributyl citrate (TBC) was added to make the prepared PLA/CA composite membrane have good flexibility and high transparency. The results of FE-SEM and FTIR showed that CS and AL were uniformly dispersed in PLA matrix and had good compatibility with PLA. The antioxidant activities of PLA/CS and PLA/AL composite films were 43.3 % and 72.8 %, respectively. At the same time, the inhibitory rates of PLA/CS membrane against Escherichia coli and Staphylococcus aureus were as high as 87.91 % and 75.17 %, respectively. PLA/AL films exhibit excellent UV barrier properties. When the environmental pH (ammonia and acetic acid vapor) changed repeatedly, the PLA/AL membrane showed reversible color change of yellow under acidic condition and purple under alkaline condition. During the packaging and storage of chicken breast meat, the freshness of chicken breast meat can be detected by the color change of functional PLA/CA composite membrane.

Vapor-induced polyelectrolyte complexation of chitosan/pectin: A promising strategy for the preparation of hydrogels for controlled drug delivery

An innovative vapor-induced polyelectrolyte complexation process mediated by the acetic acid vapor is reported in this study as an alternative to preparing hydrogels of chitosan and pectin. Usually, this kind of hydrogel is prepared by the conventional solution mixture method, which results in materials with limited properties. Beyond demonstrating the efficiency of this process, a deep investigated throw light into the structure-properties relationships of these hydrogels, which could be useful to orientate their further application. The different characterization analyses demonstrated that the hydrogels obtained through the polyelectrolyte complexation of chitosan and pectin using this alternative method possess ordered regions within their structures. This configuration results from the packing of the polysaccharide chains due to the strong electrostatic interactions among the charged functional groups, being a direct result of the slow-rate complexation process driven by the vapor-induction. In terms of application, this structural characteristic of the hydrogels prepared by the vapor-induced method was pivotal to controlling and prolonging the release rate of curcumin, which was previously encapsulated into these hydrogels. Moreover, the experimental data for the release of CUR from these hydrogels was well-fitted by zero-order kinetics, differing from the hydrogels prepared through the conventional mixture of chitosan/pectin solutions. In summary, the molecular and microstructural understanding of the polyelectrolyte complexation of chitosan and pectin driven by this original vapor-mediated method raises as an alternative to prepare hydrogels with specific and tailored properties, which can be beneficial for drug delivery applications.

Surface preparation of metal films by gas cluster ion beams using organic acid vapor for Cu–Cu bonding

Surface-activated bonding (SAB) of Cu by gas cluster ion beam (GCIB) irradiation with acetic acid vapor was studied. GCIB irradiation realizes surface smoothing and surface reaction enhancement without severe damage. Therefore, it is promising for SAB. In this study, acetic acid vapor was introduced during Ar-GCIB irradiation to assist the removal of surface oxides on the Cu surface. XPS results showed that Cu(OH)2 was effectively removed by reaction with adsorbed acetic acid, and there was no residue by acetic acid adsorption. In addition, surface roughness decreased by Ar-GCIB irradiation with acetic acid because of the preferential removal of protrusion. Preliminary bonding experiments showed an increase of Cu–Cu bond strength by Ar-GCIB irradiation with acetic acid vapor.

The Permeability of PET by Formic and Acetic Acid Vapors

ABSTRACT The permeability of biaxially oriented polyethylene terephthalate, PET, to vapors from 5%, 30%, and 100% formic acid solutions as well as the vapor from a 30% acetic acid solution was measured by gravimetric analysis in order to determine the transmission rate of the vapors through PET folders and enclosures made from Mylar™ and similar materials, and ultimately understand the microenvironment that is created inside an encapsulate. The data shows that the permeation of formic acid vapor is at least two orders of magnitude slower than the permeation of water vapor. Measurements of the permeation of 30% acetic acid vapor through PET seemed to be due to the permeation of the water only, and the permeation of the acetic acid, if it occurred, occurred too slowly to be measured. The size of the diffusing molecule determines the permeation. Since the permeability decreases as the size of the diffusing vapor molecule increases, a plot of permeability versus vapor size allows the permeability of various other vapors through PET to be predicted. Colorimetry showed that porous PET allowed ambient vapors to diffuse into the encapsulate, and the entire paper within the encapsulate was affected, not only the paper near the holes in the PET.

Surface preparation of metal films by gas cluster ion beams using organic acid vapor for Cu-Cu bonding

Abstract Surface activated bonding of Cu by gas cluster ion beam (GCIB) irradiation with acetic acid vapor was studied. GCIB irradiation realizes surface smoothing and surface reaction enhancement without severe damage. Therefore, it is promising for surface-activated bonding (SAB). In this study, acetic acid vapor was introduced during Ar-GCIB irradiation to assist removal of surface oxides on Cu surface. XPS results showed that Cu(OH)2 was effectively removed by reaction with adsorbed acetic acid, and there was no residue by acetic acid adsorption. In addition, surface roughness decreased by Ar-GCIB irradiation with acetic acid because of the preferential removal of protrusion. Preliminary bonding experiments showed increase of Cu-Cu bond strength by Ar-GCIB irradiation with acetic acid vapor.

High-Sensitivity Metal Oxide Sensors Duplex for On-the-Field Detection of Acetic Acid Arising from the Degradation of Cellulose Acetate-Based Cinematographic and Photographic Films

In this work, a system consisting of two resistive sensors working in tandem to detect and quantify the acetic acid released during the degradation of cellulose acetate-based ancient cinematographic and photographic films is presented. Acetic acid must be constantly monitored to prevent reaching concentrations at which autocatalytic degradation processes begin. The sensors are constituted by a thin layer of metal oxide (tungsten oxide and tin oxide) deposited over an interdigitated electrode capable of being heated, chosen to maximize the array response towards acetic acid vapors. The signals obtained from the sensor array are mathematically processed to reduce the background signal due to interferent gases produced during degradation of ancient cinematographic films. The sensor array reported a LOD of 30 ppb for acetic acid, with a linearity range up to 30 ppm. Finally, the sensor array was tested with different cinematographic and photographic film samples made of cellulose acetate, whose degradation state and acetic acid production was validated using the conventional technique (A-D strips). The presented array is suitable for remote monitoring large number of films in collections since, compared to the official technique, it has a lower detection limit (30 ppb vs. 500 ppb) and is much quicker in providing accurate acetic acid concentration in the film boxes (15 min vs. 24 h).