P-phenolsulfonic Acid Research Articles

Efficient abatement of recalcitrant p-phenol sulfonic acid by CoFe2-xMoxO4 catalyzed peroxymonosulfate

P-phenol sulfonic acid (PSA) is a very noxious and refractory emerging pollutant owing its chemical stability. In this study, CoFe2-xMoxO4 as heterogeneous catalysts were fabricated via a hydrothermal route and investigated as peroxymonosulfate (PMS) activator for PSA removal. X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analyses indicate a well-maintained structure, suitable particle size, and larger surface area nanoparticles which offer a further active surface for the catalytic reaction. X-Ray photoelectron spectroscopies (XPS) confirm the valence and chemical structure of CoFe2-xMoxO4 with different ratios of Mo ion. CoFe2-xMoxO4/PMS degraded 88% with rate constant of 0.109 min−1 in 60 min under the reaction conditions ([PSA] = 185 mg L−1, [CoFe2-xMoxO4] = 0.3 g L−1, [PMS] = 5 g L−1, T = 20 °C, pH = 3.5). The increasing content of Mo (i.e. 0.1–1.0) in CoFe2-xMoxO4 enhanced the degradation rate, signifying that the catalytic performance was positively correlated with Mo content in the catalyst composition. The results of electron paramagnetic resonance (EPR) suggested that SO4·− and HO· radicals predominated in PMS activation by CoFe2-xMoxO4. Overall, the findings offer the applicability of such metal oxide heterogeneous catalysts for the remediation of highly recalcitrant pollutants in ambient conditions.

Revisiting Disinfection Byproducts with Supercritical Fluid Chromatography-High Resolution-Mass Spectrometry: Identification of Novel Halogenated Sulfonic Acids in Disinfected Drinking Water.

High resolution mass spectrometry (HRMS) coupled to either gas chromatography or reversed-phase liquid chromatography is the generic method to identify unknown disinfection byproducts (DBPs) but can easily overlook their highly polar fractions. In this study, we applied an alternative chromatographic separation method, supercritical fluid chromatography-HRMS, to characterize DBPs in disinfected water. In total, 15 DBPs were tentatively identified for the first time as haloacetonitrilesulfonic acids, haloacetamidesulfonic acids, and haloacetaldehydesulfonic acids. Cysteine, glutathione, and p-phenolsulfonic acid were found as precursors during lab-scale chlorination, with cysteine providing the highest yield. A mixture of the labeled analogues of these DBPs was prepared by chlorination of 13C3-15N-cysteine and analyzed using nuclear magnetic resonance spectroscopy for structural confirmation and quantification. A total of 6 drinking water treatment plants utilizing various source waters and treatment trains produced sulfonated DBPs upon disinfection. Those were widespread in the tap water of 8 cities across Europe, with estimated concentrations up to 50 and 800 ng/L for total haloacetonitrilesulfonic acids and haloacetaldehydesulfonic acids, respectively. Up to 850 ng/L haloacetonitrilesulfonic acids were found in 3 public swimming pools. Considering the stronger toxicity of haloacetonitriles, haloacetamides, and haloacetaldehydes than the regulated DBPs, these newly found sulfonic acid derivatives may also pose a health risk.

A highly active and stable organic-inorganic combined solid acid for the transesterification of glycerol under mild conditions

Solid acid catalyst plays a crucial role in the petroleum refinery industry and bio-refinery technology. In this work, p-phenolsulfonic acid (PSA) was successfully grafted onto the surface of KH560-modified zirconium phosphate (K-ZrP) in a facile routine. The structure and property of this organic-inorganic combined solid acid PSA/K-ZrP-x were characterized via XRD, FTIR, 13C solid-state NMR, TG, N2 adsorption-desorption, SEM, pyridine-adsorption FTIR and XPS technologies. The characterization results showed that KH560 can bond with ZrP and promote the grafting of PSA on the surface of K-ZrP via the condensation reaction between its epoxy ring and the phenolic hydroxyl group in PSA. Consequently, PSA/K-ZrP-2 exhibited excellent performance and stability in the transesterification between glycerol and methyl acetate among the tested H3PW12O40, Amberlyst-45, HBEA, HZSM-5, ZrP, AlCl3 and FeCl3 catalysts. The calculated conversion of glycerol reached 81.3% with a 97.9% selectivity for monoacetin (MAG) and diacetin (DAG) with a 2.2% dosage of [H+] at 100 °C for 4 h. The highest specific activity of PSA/K-ZrP-2 reached 24028.2 mg-glycerol/g-cat/h in a short reaction time (at 0.17 h), and it could be recycled five times without obvious deactivation.

Benzenesulfonic Acid - an Green Efficient Esterification Catalysts for Continuous Synthesis of n-propyl Acetate

The esterification of acetic acid and n-propanol catalyzed by benzenesulfonic acid and its derivatives in the batch and continuous rectification tower was studied, in order to develop a new effective and green catalyst instead of the oxidative and corrosive sulfuric acid. A series of the comparison system with sulfuric acid was build for the targeted and fast evaluation of catalysts. The results showed that the catalytic esterification activity of p-phenolsulfonic acid and p-toluenesulfuric acid is very closed to sulfonic acid in the continuous rectification tower. Furthermore, the stability test for continuous esterification with p-toluenesulfuric acid presented that the high yield of n-propyl acetate could maintain 50 hours and stability. Therefore, p-phenolsulfonic acid and p-toluenesulfuric acid could be prospective substitutes for sulfuric acid for the continuous synthesis of n-propyl acetate in the rectification tower.

A mesoporous polysulfonic acid-formaldehyde polymeric catalyst for biodiesel production from Jatropha curcas oil

A highly reactive acid-functionalized polymer is prepared by the simple condensation of aqueous formaldehyde and p-phenolsulfonic acid and used as a solid catalyst in concerted (trans)esterification. This yields biodiesel from Jatropha oil without the need to remove water by-product from the reaction mixture. An isolated biodiesel yield of 98 ± 2% is achieved using a catalyst loading of 10 wt %, methanol:oil ratio of 12:1, temperature of 90 °C, and reaction time of 6 h. The high activity of our catalyst is attributed to its porous nature and the co-inclusion of reactive SO3H sites and phenolic OH groups. Advantageously, these groups are hydrophilic, allowing the catalyst to remain highly active in the presence of H2O. Nine methyl ester components are identified in the biodiesel product, with 9-octadecanoic acid methyl ester (C18:2, 64.92%) and hexadecanoic acid methyl ester (C16:0, 16.44%) as the major constituents. The catalyst is evaluated over 4 cycles, maintaining a 92 ± 2% isolated yield. Physicochemical analysis of the spent catalyst by SEM-EDX suggests this decrease is due to some loss of mesoporosity and sulfur content.

Synthesis of solketal from glycerol over modified SiO2 supported p-phenolsulfonic acid catalyst

Acetalization of glycerol with acetone could convert surplus glycerol into an important fuel additive (solketal). In this work, a stable solid acid catalyst was synthesized in a facile polycondensation of p-phenolsulfonic acid on KH560 modified SiO2 (PSF/K-SiO2) and used in the acetalization of glycerol at room temperature. Characterization results confirmed that PSF/K-SiO2 possessed larger surface area and surface acidity than that of PSF resin (copolymer of p-phenolsulfonic acid and formaldehyde) and non-modified SiO2 supported PSF resin (PSF/SiO2). As a result, PSF/K-SiO2 was extremely active and stable in the acetalization of glycerol. At 25 °C, the detected conversion of glycerol reached 86.3% with a 97.7% selectivity of solketal at 1.5 h. The best yield of solketal over PSF/K-SiO2 could reach 93.1 g-solketal/g-cat/h, and PSF/K-SiO2 could be recycled at least 5 times without obvious decrease in reactivity.

Second-Generation meta-Phenolsulfonic Acid-Formaldehyde Resin as a Catalyst for Continuous-Flow Esterification.

A second-generation m-phenolsulfonic acid-formaldehyde resin (PAFR II) catalyst was prepared by condensation polymerization of sodium m-phenolsulfonate and paraformaldehyde in an aqueous H2SO4 solution. This reusable, robust acid resin catalyst was improved in both catalytic activity and stability, maintaining the characteristics of the previous generation catalyst (p-phenolsulfonic acid-formaldehyde resin). PAFR II was applied in the batchwise and continuous-flow direct esterification without water removal and provided higher product yields in continuous-flow esterification than any other commercial ion-exchanged acid catalyst tested.

Esterification of glycerol with acetic acid over SO3H-functionalized phenolic resin

A series of SO3H-functionalized phenolic resin-based catalysts (PSPF-x) with different molar ratio of p-phenolsulfonic acid (PhOH-4-sa) and phenol (PhOH) were prepared via a facile polycondensation method, and employed in the esterification of glycerol with acetic acid under mild conditions. It was found that PSPF-3 (the molar ratio of PhOH-4-sa to PhOH in feed was 3:1) exhibited excellent activity and stability. The detected conversion of glycerol was 81.6% with a 98.9% selectivity of MAG and DAG at 70 °C under stoichiometric molar ratio of acetic acid to glycerol (3:1) for 7 h. The highest turnover frequency of each acid site in PSPF-3 reached 341.1 h−1 at the beginning of the reaction and it could be recycled for 5 times. Characterization results indicated that the performance of PSPF-3 could be attributed to its stable cross-linking structure, enhanced surface area and porosity. The reaction mechanism was proposed on the base of a series of experiments.

Acid-Functionalized Mesoporous Polymer-Catalyzed Acetalization of Glycerol to Solketal, a Potential Fuel Additive under Solvent-Free Conditions

A mesoporous phenolsulfonic acid–formaldehyde polymeric acid catalyst was synthesized simply by condensation polymerization of p-phenolsulfonic acid and an aqueous solution of formaldehyde. The acid-functionalized polymer was used as a heterogeneous catalyst for glycerol acetalization with acetone for synthesis of solketal without the requirement of water removal from the reaction mixture. Solketal is extensively used as an additive for the formulation of petrol, diesel, and biodiesel. The effect of reaction parameters, such as the reaction temperature, time, catalyst loading, and glycerol/acetone molar ratio, on the glycerol conversion was exhaustively investigated in detail. Glycerol conversion of 97% and product selectivity of 100% were attained under the optimized reaction conditions: time of 4 h, temperature of 60 °C, catalyst loading of 8 wt %, and glycerol/acetone ratio of 5:1. Recycling of the used catalyst revealed good repeatability without any reactivation until the fourth cycle with a minimal ...

EFFECT OF RADICAL SCAVENGERS AND PROPOSED PATHWAYS FOR DEGRADATION OF AZO DYE IN AQUEOUS SOLUTION UNDER PRESENCE OF IRON(III) AND PERSULPHATE

The degradation process of Acid Orange 7 (AO7) in aqueous solutions by iron(III) under activation by persulfate (PS, S2O82-) oxidation and Visible (Vis) light (≥420 nm) exposure has been studied. The radical scavenging effect was examined by using ethanol (EtOH), tert-butyl alcohol (TBA) and sodium azide to state that the hydroxyl radical (·OH) is regarded as the predominant reactive oxidant for the AO7 decolorization, while the sulfate radical (SO4·-) and singlet oxygen(1O2) are also make their contribution to dye's degradation. The reaction intermediates were determined by electrospray ionization-mass spectrometry (ESI-MS) analysis, and a probable degradation pathway mechanism has been proposed. It was suggested, that firstly an initial successive radical attacks the N atom of the dye, which decompose to p-phenolsulfonic acid and 1,2-naphthaquinone through the contemporaneous break of two C-N bonds. Afterwards, subsequent oxidation of these products and loss of the −SO3− group are observed. Finally, the acyclic carboxylic acids are formed from the central ring-opening, and then the further oxidation to simple carboxylic acids is evident. The work can provide a simple, effective and economic system for the treatment of non-biodegradable azo dye. The recommendations were proposed on organization of an effective quality control of technological water discharge and products of its processing at the local wastewater treatment facilities of industrial plants for prevention of the ingress of hazardous biological substances to the hydrosphere.Forcitation:Heng Zhong, Hui Zhao, Jun Li, Lei Sun, Aihua Xu, Dongsheng Xia, Nevsky A.V. Effect of radical scavengers and proposed pathways for degradation of azo dye in aqueous solution under presence of iron (III) and persulphate. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 4. P. 88-94.

The mechanism of bound hydroxyl radical formation and degradation pathway of Acid Orange II in Fenton-like Co2+-HCO3− system

The catalytic degradation of organic dyes with low cost Fenton-like systems over a wide pH range has become an object of numerous studies in the last two decades. Co2+-HCO3− system has recently been demonstrated as a simple and efficient approach of acid orange II (AOII) decolorization, even in the presence of a significant amount of common anions in water. However, a detailed mechanism, especially the generation and action of reactive oxygen species (ROS), remains unclear. In this work, the oxidation-reduction cycle of Co2+ ions, the production of ROS and the formation of intermediate products were discussed, giving insight into the mechanistic details of the system. It was found that the bound HO radicals were produced as the main reactive species during Co(II) oxidation to Co(III) by H2O2. The radicals attacked the two C-N bonds in the azo dye simultaneously, leading to the decomposition of the dye into p-phenolsulfonic acid, 1,2-naphthaquinone and N2. The cobalt(III) species was not active, but its reduction was suggested to be the rate-limiting step for the reaction, during which O2− radicals were formed and partly contributed to AOII decolorization.

Sensitivity of human dental pulp cells to eighteen chemical agents used for endodontic treatments in dentistry

To determine the adverse effects against human dental pulp tissue, the sensitivity of human dental pulp cells (D824 cells) to 18 chemical agents used for endodontic treatments in dentistry was examined. The cytotoxicity, as determined by a decrease in colony-forming ability of cells treated with the chemical agents, increased as the concentration increased. As a quantitative measure of the cytotoxic effect, LC(50), the concentration which induces a 50% lethality, was extrapolated from the concentration-response curves. The rank of the chemical agents according to their cytotoxic effect (LC(50)) was sodium arsenite>formaldehyde>hydrogen peroxide>zinc oxide>thymol≈iodoform≈eugenol>guaiacol>ethylenediaminetetraacetic acid≈iodine>procaine>lidocaine≈chloramphenicol≈m-cresol>calcium hydroxide≈sodium hypochlorite≈phenol≈p-phenolsulfonic acid. To compare the cytotoxicity and the levels of apoptosis and mRNA expression of five genes related to the function of dental pulp tissue, D824 cells treated with the LC(50) concentrations of chemical agents were assayed by the TUNEL method and quantitative reverse transcription polymerase chain reaction analysis, respectively. The inducibility of apoptotic cells and the level of mRNA expression of the genes varied with the chemical agents, indicating that both effects occurred independent of the rank of cytotoxic effect of the chemical agents. The results not only provide information concerning cytotoxicity of various chemical agents to human dental pulp cells, but also show an insight into the diversity of the pharmacodynamic action of the chemical agents.

Studies on the synthesis, structure, growth and physical properties of an organic NLO crystal: 2-Amino-5-nitropyridinium Phenolsulfonate

A noncentrosymmetric crystal was prepared from 2-amino-5-nitropyridine (2A5NP) and p-Phenolsulfonic acid, which was designed for second harmonic generation. Good quality single crystals of 2-amino-5-nitropyridinium Phenolsulfonate (2A5NPP) were successfully grown by the slow evaporation method with dimensions 10 × 4 × 3 mm 3. The unit cell dimensions were determined from single crystal X-ray diffraction studies. The structural perfection of the grown crystals has been analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. Fourier transform infrared (FTIR) spectral studies have been performed to identify the functional groups. The optical transmittance window and the lower cutoff wavelength of the 2A5NPP have been identified by UV–vis–NIR studies. Thermo gravimetric analysis (TGA) and differential thermal analysis (DTA) were used to study its thermal properties. Powder test with Nd:YAG laser radiation shows a high second harmonic generation. The laser induced surface damage threshold for the grown crystal was measured using Nd:YAG laser.

Planate conducting polymer actuator based on polypyrrole and its application

In this study, we propose a planate actuator which can transform only its central part locally. We have developed a planate conducting polymer actuator based on polypyrrole (PPy) and two types of acids, such as p-phenol sulfonic acid and dodecylbenzene sulfonic acid, by electrodeposition. Its structure was patterned bimorph structure with anion-driven, cation-driven and bimorph layers. The planate conducting polymer actuator could deform only its central part locally. Moreover, we introduce a micro-pump that operates by planate conducting polymer actuator as the drive source. The water level in the flow channel of micro-pump shows the reciprocating motion measuring ±2 mm in accordance with the oscillation of the bimorph conducting polymer actuator which was approximately 28 μl/min. The oscillating volume can be controlled by the application of electrochemical potential and its scan rate applied to the actuator.

Sn-P Alloys for Rapid and Stable Production of Tin Solution for Tin Plating

For fast preparation of tin solution for electrodeposition, the dissolution characteristics controlled by oxygen reduction were investigated for Sn metal and Sn-P alloys containing cathodic inclusions using electrochemical measurement in p- phenolsulfonic acid. The dissolution rate of tin increased with phosphorus content of the alloys due to faster oxygen reduction and showed the maximum at about 1 at % phosphorus. The cathodic inclusions were dispersed in the Sn matrix by water quenching of molten mixture of Sn and Sn-50at%P, and were identified as the Sn4P3 phase by X-ray diffraction. The Sn4P3 compound has the higher activity for oxygen reduction than Sn metal and platinized platinum. The mechanism for the cathodic reduction of dissolved oxygen on Sn metal and Sn-P alloys was investigated in p-phenolsulfonic acid. Increasing phosphorus content of Sn-P alloys resulted in an increase in the limiting oxygen reduction current density which was proportional to the partial pressure of oxygen, but independent of pH. It was concluded that the rate-determining process of oxygen reduction was adsorption of oxygen molecule on the Sn metal and Sn-P alloys.

Ozonation of Non-Biodegradable Mixtures of Phenol and Naphthalene Derivatives in Tanning Wastewaters

The decomposition of non-biodegradable mixtures of phenol and naphthalene derivatives in aqueous solution by ozonation is investigated. The toxic water pollutants are the intermediate synthesis products obtained via the sulfonation reaction of naphthalene and phenol. These organic compounds are phenol (PH), p-phenol sulfonic acid (p-PSA), and 2-naphthalene sulfonic acid (2-NSA). The kinetic study of ozonation is realized by the pH variation in the range of 2–12. The pH-dependence of the ozone reactivity for different organics is observed. The intermediates and final products determination is measured by UV absorbency and HPLC technique. It is shown that the main sub-products are muconic, fumaric, maleic and malonic acids and catechol. The final products are basically oxalic acid and formic acids as well as formaldehyde. In the initial stage of ozonation, hydroxylation and desulfuration of p-PSA and 2-NSA is detected. The effect of the preliminary ozonation on the biodegradability of the contaminants is estimated by BOD5/COD-ratio variation, which significantly increases from 0.15 to 0.88.

Ability of 13 chemical agents used in dental practice to induce sister-chromatid exchanges in Syrian hamster embryo cells

To evaluate the genotoxic potential of 13 chemical agents used in dental practice, the abilities of these agents to induce sister-chromatid exchanges (SCEs) were examined using Syrian hamster embryo (SHE) cells. Statistically significant increases in the frequencies of SCEs were observed in SHE cells treated with all seven of the chemical agents used as endodontic medicaments: p-chlorophenol, m-cresol, formaldehyde, guaiacol, hydrogen peroxide, p-phenolsulfonic acid, and sodium hypochlorite (P < 0.01; Student t test). Assessment of two chemical agents that are applied to the oral mucosa as antiseptics showed that SCEs were induced by iodine (P < 0.01), but not by chlorhexidine. Of three chemical agents that are used as dyes for disclosing dental plaque, erythrosine B had no effect on SCE induction, while acid fuchsin and basic fuchsin increased the SCE frequencies in SHE cells (P < 0.01). Glutaraldehyde, which is used as a disinfectant for dental instruments and impressions, also induced SCEs (P < 0.01). Because SCE assays are used as a sensitive indicator for evaluating genetic toxicity of chemicals, the chemical agents that had a positive response in the present study are potentially genotoxic to mammalian cells.

Decolorization of orange II by catalytic oxidation using iron (III) phthalocyanine-tetrasulfonic acid

Orange II, C.I. Acid Orange 7 (AO7), is oxidatively decolorized via catalytic oxidation by iron(III) phthalocyanine-tetrasulfonic acid (Fe(III)-PcTS) as a biomimetic catalyst and KHSO 5 as an oxygen donor. The nature of the decolorization of AO7 was investigated in the catalyst concentration range of 10–50 μM, in which the initial concentration of AO7 was 417 mg l −1. A 99.6% decolorization was observed at [KHSO 5] = 2.5 mM and [Fe(III)-PcTS] = 20 μM after a 3-h reaction period. However, the fact that only 4.9% of the TOC was removed indicated that the conversion to CO 2 was incomplete. The results of a total organic nitrogen analysis of the reaction mixture showed that the nitrogen in the azo chain was mainly converted to N 2 gas. In addition, 38.6% of the AO7 was converted to 1,2-dihydroxynaphthalene, and 21.4% to p-phenolsulfonic acid. These results indicate that the degradation via this catalytic system involves the conversion of AO7 to phenolic compounds, followed by N 2 production. In addition, a Microtox test showed that toxicity of the solution increased as a result of AO7 oxidation using this catalytic system.

Cyclic voltammetric and electrochemomechanical characteristics of freestanding polypyrrole films in diluted media

Cyclic voltammograms and electrochemomechanical deformations (ECMD) in freestanding polypyrrole (PPy) films have been investigated as a function of electrolyte concentration. It was found that both the oxidative and reductive peaks shifted towards lower potential with the dilution of the electrolyte in PPy films deposited from dodecylbenzene sulfonic acid. In the case of PPy films deposited from p-phenol sulfonic acid, the oxidation and reduction peaks tend to shift towards higher and lower potentials, respectively. These results indicate that the ion contributing to the redox reaction determines the polarity of the potential shift according to the Nernst equation. The ECMD magnitudes were also changed with electrolyte concentration. However, the efficiency of the deformation per degree of doping did not change much over 0.01 M. This indicates that the decrease in ECMD magnitude is not attributed to degradation of the ECMD behavior, but that a decrease in doping quantity for the film essentially effects the decrease in deformation magnitude in diluted media.

Cyclic Step-voltammetric Analysis of Cation-driven and Anion-driven Actuation in Polypyrrole Films

Cation-driven and anion-driven electrochemomechanical deformations (ECMD) in electrodeposited polypyrrole (PPy) films have been investigated by means of cyclic voltammetry and cyclic step-voltammetry (CSV). The film deposited from hydrochloric acid (PPyCl) expanded upon anodic reaction (anodic expansion) while that deposited from dodecyl-benzene sulfonic acid (PPyDBS) exhibited cathodic expansion. In the case of the film deposited from p-phenol sulfonic acid (PPyPPS), it was found to show the anodic expansion at 600 mV (vs Ag wire as a reference electrode) along with the cathodic contraction at -800 mV in CSV. The film obtained from the same lot, however, showed cathodic contraction and anodic expansion only by changing the oxidative potential from 600 mV to -100 mV. This phase inversion indicates that not only the polymerization electrolyte but also the redox potential determines the (de)insertion of ions in the PPyPPS film. Contractive electrochemical creeping was only observed in PPyPPS film in chloride salt electrolytes, indicating that the cation insertion induces the deinsertion of initial-dopant anion from the film.