Aniline In Solution Research Articles

Efficient generation of 1O2 by activating peroxymonosulfate on graphitic carbon nanoribbons for water remediation

Few-layer graphitic carbon nanoribbons (GCN) with rich defective sites were prepared by pyrolysis at 800 oC in N2 of in situ-chelated Fe-polyaniline complexes synthesized via one-pot homogeneous Fenton-like oxidative polymerization of an acidic aniline solution. A minimal amount of iron (0.47 wt%) made a pivotal role in the nanoribbon growth and graphitization of GCN, and deposited highly dispersed iron species on GCN without post-synthesis acid leaching, which greatly simplified the synthesis procedure of GCN with improved yield. GCN exhibited high activity and stability for catalytic degradation of organic pollutants with peroxymonosulfate (PMS) mainly via non-radical pathways. The influences of various operating parameters on the catalytic performance of GCN were investigated. Scavenging tests, spin-trapping electron paramagnetic resonance spectra, electrochemical analyses, and theoretical calculations unveiled that 1O2 was the main reactive oxygen species generated from synergistic activation of PMS on GCN while GCN-mediated electron transfer made a minor contribution to organic degradation.

Eco-Friendly Electrosynthesis of Cu-PANI-Pencil Composite: Enhanced Their Current Value, Acid Sensing, Click Chemistry and Turn On-Off Sunlight Photo-Catalytical H2O2 Activation.

In this contribution, we report a straightforwardly and easily one-step synthesis of a small family of composites based in polyaniline grafted on HB2 graphite (PANI@UG) and their copper-doped derivatives (Cu50PANI@UG5-6). The PANI@UG composites were synthesized through electrochemical polymerization using cyclic voltammetry (CV) in three different acidic media: i) acetic acid (AcOH) at high and low concentration (12 and 1 M, using KCl as electrolytic support); ii) a mixture of AcOH and sulfuric acid (H2SO4, which have two roles: as electrolytic support and proton source) and iii) a mixture of acetonitrile (NCCH3) and H2SO4, under atmospheric conditions. Once the best conditions were achieved, our next step was focused on obtaining the Cu50PANI@UG5-6 composites using a solution of aniline and CuSO4 (50 mM) in AcOH:H2SO4 and NCCH3:H2SO4 solutions, respectively. All composites were characterized by CV, FT-IR, SEM and MALDI-TOF experiments. So, the current value was enhanced for the Cu50PANI@UG6 composite, which have three potential catalytical applications in: i) HClO4 acid sensing, ii) click chemistry and iii) sunlight drive photo-activation of H2O2.

Coupled treatment of aniline and phenol in water by electrochemical copolymerization

ABSTRACT Anilines and phenols are recognized as challenging organic pollutants in industrial wastewater. Herein, the coupled treatment of aniline and phenol in water was achieved through electrochemical oxidation-induced copolymerization. After the electrolysis (1,300 mA for 10 h) in the solution of aniline and phenol (200 mL, each at a concentration of 5 g/L), the organic compounds were efficiently precipitated from their mixed solution by copolymerization. These insoluble copolymers could be easily separated by filtration and collected as brown powders, and the average removal rate of aniline and phenol was calculated as 0.6 mol/h m2 in this coupled electrolysis. The chemical oxygen demand (COD) test of the filtrates showed that it reached up to 98% of the COD removal ratio. Moreover, mixed solutions containing multiple aniline and phenol derivatives were also applicable for this coupled treatment strategy, and they were efficiently removed together after electrolysis.

Evidence for Superoxide-Initiated Oxidation of Aniline in Water by Pulsed, Atmospheric Pressure Plasma.

Plasma-driven solution electrochemistry (PDSE) uses plasma-generated reactive species to drive redox reactions in solution. Nonthermal, atmospheric pressure plasmas, when irradiating water, produce many redox species. While PDSE is a promising chemical tool, there is limited insight into the mechanisms of the reactions due to the variety of short-lived reagents produced. In this study, we use aniline as a model system for studying redox mechanisms of PDSE. We show that the plasma irradiation of aqueous aniline solutions drives the formation of polyaniline oligomer, which is suppressed under acidic starting conditions. The addition of (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPO), a radical scavenger, decreases the formation of oligomer by 80%, and the addition of superoxide dismutase fully hinders oligomerization. These results lead us to conclude that the oligomerization of aniline by plasma irradiation is initiated by superoxide. This discovery provides novel insights into PDSE mechanisms and illustrates a potential method of harnessing superoxide for chemical reactions.

Two comparative novel facile synthesis of Prussian blue/polyaniline bilayer films for supercapacitor electrode

A nanocomposite films of Prussian Blue/Polyaniline were prepared on ITO without binder, by two procedures: The first by forming thin multi layers of films of Prussian blue and Polyaniline alternatively, up to seven utilizing “layer by layer” technique. To prepare another film, a thick layer of Prussian Yellow was made under a Polyaniline layer with almost the same load of materials.PB successive layers were fabricated by dipping the ITO in a mixture of (Fe (NO3)3 + K3Fe(CN)6) solution, for a few minutes. next Pani layers were overlayed by electropolymerizing of aniline solution on the ITO/PY electrode. PY instantly was reduced by aniline as soon as dipped in solution, resulting in a nano Prussian Blue film on ITO.Uv-vis and FT-IR spectroscopy were used to characterize the fabricated films. AFM and SEM were utilized to study its morphology. The capacitive behavior of the two types of films was studied utilizing CVs and GCD techniques. The resistance of the electrode/electrolyte interface was studied by EIS. The electrochemical analysis confirmed that the multi-layer by layer thin film has much-improved specific capacitance of 255.6 F/g at 1 A/g current density and superior stability of 96.4 % of its initial value after 500 cycles.

Multifunctional g-C3N4-PDI/MOF-545-NH2 photocatalyst for Enhanced CO2 reduction and aniline oxidation

The use of solar energy to convert CO2 into clean energy is one of the ideal strategies for achieving carbon neutrality. However, the rapid recombination of photogenerated electron holes, the complexity of the reduction products and the consumption of sacrificial materials severely limit its development and application. In this work, g-C3N4-PDI (CNP) and MOF-545-NH2 (MNH) were prepared by calcination and hydrothermal methods, respectively, and CNP/MNH photocatalysts were prepared by in situ growth of MNH on CNP surface. The photocatalytic CO2 conversion reaction of CNP/MNH in triethanolamine and aniline solutions was investigated. Experiments show that the prepared CNP/MNH catalyst has excellent photocatalytic performance. When triethanolamine was used as a sacrificial agent, the yield of CH4 reached 192.7 μmol·g−1·h−1 (selectivity 92.94 %). In particular, while the catalyst realizes the conversion of CO2 in the aniline solution, it is surprising to find that part of the CO2 is converted to ethanol. The catalyst’s photochemical properties, CO2 reduction pathway, and aniline oxidation products were characterized by XPS, UV–vis DRS, PL, electrochemistry, zeta potential, ESR, GC–MS and in-situ infrared spectroscopy. The results show that the modification of the catalyst and the formation of heterojunction not only increase the adsorption of CO2, but also accelerate the process of photogenerated electron migration, which plays an important role in the process of carbon dioxide conversion. This study provides a new perspective for the design of photocatalytic CO2 conversion catalysts, and also provides a feasible method for aniline wastewater treatment.

Flexible polyaniline@carbon nanofiber membrane pH electrode for health care

A low-cost flexible polyaniline@carbon nanofiber membrane (PANI@CNM) electrode was fabricated by chemical in situ polymerization of aniline monomer for pH detection. The preparation condition, morphology, chemical structure and the electrochemical properties of the PANI@CNM electrode were investigated. The result showed that PANI@CNM electrode with high sensitivity of 76.2 mV/pH was prepared with 0.3 M aniline solution and hydrochloric acid as the doping acid at 0℃ for 6 h. FTIR and Raman analysis suggested that the pH sensibility of PANI is attributed to the super-Nernstian behavior of the PANI in the emerald imine form. The PANI@CNM working electrode performs a stable electrochemical property without interference by the common metal iron and biochemical, and has an outstanding reversible pH response in the pH range of 6.32–8.34 without interference of deformation. It also maintained a stable sensing performance in the temperature range of 25-40℃ for long time use and presented excellent biocompatibility. Generally, the PANI@CNM working electrode exhibits great potential in flexible biomedical and wearable pH detection application.

From white pollution to green coating—PS/PANI anti-corrosive coatings from waste PS foams

Polystyrene (PS) foam is a major component of “white pollution”, which has become a global environmental issue. How to solve the problem of white pollution has caused extensive research all around the world. In this paper, a simple way to transform waste polystyrene foam into green anti-corrosion coating was proposed through a seed polymerization method of polyaniline (PANI). PS foam was dissolved in aniline and ethyl acetate solution, afterwards PANI seeds and ammonium persulfate (APS) was added in, then the polymerization was initiated to form PS/PANI composites which could be used as the anti-corrosive coating. The physical properties and anti-corrosion performance of the coatings were detailed discussed. According to electrochemical impedance spectroscopy (EIS) results, the PS/PANI coatings have great corrosion resistance. When the mass percentage of aniline to PS was 30 % in the synthesis process, the protection efficiency of the products reached 99.99 % and the polarization resistance reached 6.524 × 106 Ω in 3.5 wt% NaCl solutions. Under the same condition, the charge transfer resistance was 2.81 × 103 Ω.In a word, this paper provides a new route for recycling wasted polystyrene foam. The wasted PS foams known as “white pollution” were used as a main raw material for production of “green anti-corrosion coatings”. This simple processing method is in line with the sustainable development strategy and economic system construction.

Remediation of aniline-contaminated aquifer by combining in-well Rhizobium borbori and circulated groundwater electrolysis

Aniline has become a common groundwater contaminant due to its wide use as a raw material in agriculture and pharmaceutical products. The current technologies for in situ remediation of aniline in groundwater are limited by the strains deficient in bacterial species, limited oxygen supply, excessive waste gas load and cost. Accordingly, we conducted a laboratory sand tank experiment to remediate groundwater contaminated with aniline by combining circulated groundwater electrolysis and in-well Rhizobium borbori, which was isolated from activated sludge. The results of the experiment indicated that the optimum concentration of aniline for Rhizobium borbori is about 5 mg/L, beyond which the maximum cell density and the highest specific growth rate decreases as the aniline concentration increases. The optimized duration for immobilizing the Rhizobium borbori into the bioreactor is 4–5 days. Though the Rhizobium borbori was strongly inhibited by the high-concentration of aniline, the immobilized bioreactor in the 350 mg/L aniline solution successfully formed biofilm. The aniline volatilization had limited influence on the observation of bioremediation performance, and the combination of circulated groundwater and in-well Rhizobium borbori supplied a steady dose of oxygen to the bioreactor efficiently degrading the entire region between the injection and extraction well. In addition, a numerical model for the sand tank remediation experiment was used to estimate the yield coefficient of oxygen to be 0.484 g/g, which indicates the presence of ammonia nitrogen as by-products; accordingly, a smaller wellbore size as well a higher circulation flow rate and intensity of current are recommended to improve the water quality. Despite the positive outcomes and potential of the newly developed technology to degrade subsurface aniline, parallel experiments should be conducted to estimate the environmental risk of the by-products and explore the controlling mechanisms of each component in this comprehensive system.

Etching of TiO2(110) Single-crystal Surface with Aniline for Step Direction Control

Abstract After subjecting a hydrofluoric acid treated and annealed TiO2(110) single-crystal substrate to immersion in an ethanol solution of aniline, a uniform step structure in the [001] direction was observed on the TiO2(110) surface without aniline. Since this finding is considered to control the step direction on the TiO2(110) surface, the formed surface was discussed in detail and a model of the step line formation process was proposed.

Probing the kinetics of chemical reactions in ultra-small droplet samples using digital microfluidic nuclear magnetic resonance spectroscopy

In this study, we present a digital microfluidic (DMF) system that connects analyte droplets with planar microcoils in a high-field nuclear magnetic resonance (NMR) spectrometer for in situ photoreaction analysis. Transparent indium tin oxide glass was employed in fabricating the DMF electrode chips. NMR spectroscopy was utilized for its superior sensitivity and ability to detect small changes in molecular structure, making it highly advantageous for chemical analysis. Utilizing Computer Simulation Technology Studio Suite, we designed a plane annular microstrip coil that accurately matches droplet shape to optimize detection sensitivity and increase filling factor. An advanced DMF control circuit remotely manages droplet samples and facilitates precise mixing for in situ reaction analysis. Our results demonstrate improved sensitivity in the in situ experimental analysis, such as the aldehyde amine reaction (sodium benzaldehyde-2-sulfonate solution and aniline solution) and photopolymerization reaction (polyethylene glycol ester). The integration of DMF and NMR technologies provides a promising approach for increasing efficiency and accuracy in chemical analysis.

A Sandwich Structure of Fulvic Acid and PMIDA-Modified LDHs for the Simultaneous Removal of Cu2+ and Aniline in Multicomponent Solutions

The coexistence of organic and inorganic pollutants in industrial wastewater has emerged as a concerning environmental issue worldwide due to the critical levels of biological toxicity of these pollutants. In this context, the present study proposes a sandwich structure of fulvic acid and PMIDA-modified LDHs (FA/PMIDA-LDHs) for the simultaneous removal of Cu2+ and aniline from wastewater. The specific structure was synthesized using a combination of coprecipitation and impregnation methods. Abundant benzene rings and oxygen-containing functional groups greatly increased the number of sites for the adsorption of both Cu2+ and aniline. The maximum adsorption capacity of Cu2+ and aniline in solution with initial pH 5.0 at 25 °C could reach 221.24 and 132.28 mg/g, respectively. Cu2+ could be chelated by the functional groups in the FA/PMIDA-LDHs structure, and a coupled reduction-complexation mechanism was proposed for this process. The uptake of aniline on FA/PMIDA-LDHs was demonstrated to be a result of the combination of coordination forces, hydrophobic effects, π-π interactions, and hydrogen bonds. In a multicomponent solution, FA/PMIDA-LDHs exhibited excellent salt tolerance of up to 1000 mg/L of Na+ or Ca2+. The effects of Fe3+, Ni2+, Cl-, Cr2O72-, SO42-, and H2PO4- on the uptakes of Cu2+ and aniline were also investigated.

Oxygen Vacancy-Mediated Activates Oxygen to Produce Reactive Oxygen Species (ROS) on Ce-Modified Activated Clay for Degradation of Organic Compounds without Hydrogen Peroxide in Strong Acid.

The treatment of acid wastewater to remove organic matter in acid wastewater and recycle valuable resources has great significance. However, the classical advanced oxidation process (AOPs), such as the Fenton reaction, encountered a bottleneck under the conditions of strong acid. Herein, making use of the oxidation properties of CeAY (CeO2@acid clay), we built an AOPs reaction system without H2O2 under a strong acid condition that can realize the transformation of organic matter in industrial wastewater. The X-ray photoelectron spectroscopy (XPS) proved that the CeAY based on Ce3+ as an active center has abundant oxygen vacancies, which can catalyze O2 to produce reactive oxygen species (ROS). Based on the electron spin-resonance spectroscopy spectrum and radical trapping experiments, the production of •O2- and •OH can be determined, which are the essential factors of the degradation of organic compounds. In the system of pH = 1.0, when 1 mg CeAY is added to 10 mL of wastewater, the degradation efficiency of an aniline solution with a 5 mg/L effluent concentration is 100%, and that of a benzoic acid solution with a 100 mg/L effluent concentration is 50% after 10 min of reaction. This work may provide novel insights into the removal of organic pollutants in a strong acid water matrix.

Effects of aniline on growth, oxidative and DNA damage of rice (Oryza sativa L.) seedlings

Aniline is widely used in the fields of industry and agriculture. Aniline pollution is emerging as a serious global environmental problem, whereas the toxicity and the stress mechanism on higher plants is unclear. In order to clarify the mechanism of growth, oxidative and DNA damage caused by aniline in higher plants, we cultured two varieties of rice in different concentration of aniline solution. The results demonstrated that the germination rate, amylase activity and lipase activity were significantly inhibited during the germination period of rice when aniline concentration was ≥ 25 mg L −1 ( p < 0.05 or p < 0.01). Besides, aniline also significantly inhibited the growth of rice seedlings, especially the growth of root. In comparison with the control group, the length of rice root was reduced by 17.27%–76.26% (Mudanjiang 25) and 21.20%–77.36% (Yunxian 510). The accumulation trends of . O 2 − (superoxide anion), H 2 O 2 (hydrogen peroxide), and MDA (malondialdehyde) in the two rice were increased continuously, the antioxidant enzyme activity was first increased and then decreased. When the aniline concentration was higher than 50 mg L −1 , the enzyme activity decreased rapidly (especially for Yunxian 510). Furthermore, the DNA hyperchromicity effect increased first and then decreased, which indicated that low-concentrations aniline might induce DNA breakage and high-concentrations aniline might promote the occurrence of cross-linking of DNA chains. Aniline could reduce the DNA content of the two varieties of rice shoots and roots. Especially for Yunxian 510, the DNA content of leaves and roots respective was decreased by 69.37% and 81.19% when the aniline was 200 mg L −1 , which was significantly lower than that of Mudanjiang 25 ( p < 0.01). These results evidently demonstrate that aniline maintain serious growth, oxidative, and genetic toxic effects on rice, and the Yunxian 510 was more sensitive to aniline poisoning than that of Mudanjiang 25. • Aniline had a phytotoxic–genotoxic effect on the rice growth process. • Aniline significantly inhibited rice amylase and lipase activities at concentrations >10 mg L {-1} . • Aniline significantly inhibited rice germination and growth at concentrations >25 mg L {-1} . • Aniline above 50 mg L {-1} inhibited the activity of antioxidant enzymes, resulting in increased content of ROS in rice. • Aniline lead to an increase in the degree of DNA cross-linking and a decrease in DNA content in rice.

Optimization of aniline removal using graphite assisted by response surface methodology and box-behnken design

The effectiveness of graphite as adsorbent in the removal of aniline by adsorption was investigated in batch mode based on four manipulated variables: pH of aniline solution (3, 7, 11), temperature of the incubator shaker (30°C, 40°C, 50°C), initial aniline concentration (5 ppm, 15 ppm, 25 ppm) and graphite dosage (0.5 g, 1.5 g, 2.5 g). The four manipulated variables were studied systematically through responses surface methodology (RSM) with 4-level of Box-Behnken design. A total number of 27 sets of designs with 3 centre points were created. The peak wavelengths of aniline working samples were measured at 230 nm and 280 nm using spectrophotometric method. Optimal condition of aniline adsorption revealed 15 ppm of aniline concentration with pH 3 at temperature 40°C using 1.5 g of graphite. The surface morphologies and atomic percentage of fresh and used graphite were examined by FESEM-EDX. Ultimately, graphite is proven to be an alternative in aniline removal, and more importantly, it is accessible easily as they require less processing and are abundant in nature.

Understanding the Interaction of Gluconamides and Gluconates with Amino Acids in Hair Care.

A hair care mixture formed from a gluconamide derivative and 3-hydroxypropyl ammonium gluconate is known to strengthen hair fibers; however, the mechanism by which the mixture affects hair is unknown. To give insight into the aggregation of the target gluconamide and potential interactions between the gluconate-derived mixture and hair fibers, a range of systems were characterized by X-ray crystallography namely two polymorphic forms of the target gluconamide and three salts of 3-hydroxypropylammonium with sulfuric acid, methane sulfonic acid, and oxalic acid. The gluconamide proves to aggregate and becomes a supramolecular gelator in aniline and benzyl alcohol solution. The resulting gels were characterized by rheology, scanning electron microscopy, proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, and powder X-ray diffraction.

Facile synthesis of polyaniline catalyzed by carbon fiber for supercapacitor applications

Polyaniline (PAni) widely studied conductive polymer due to its incredible versatility, electrical properties, and low cost. PAni usually is produced by chemical or electrochemical synthesis. However, these processes either generate a large amount of waste or are expensive and produce a small amount. The catalytic system incorporated into the PAni synthesis can be a strategic way to develop clean and low-cost processes. Therefore, we propose a synthesis of PAni catalyzed by carbon fiber (CF) reported for the first time. The procedure is to immerse the CF in an aqueous solution of aniline and H2SO4, at room temperature, in an open flask. Tests were carried out to investigate the CF as a catalyst and the molecular oxygen as an oxidant in the polymerization reaction. The samples were characterized by scanning electron microscopy, Raman spectroscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy. According to the analyses, the reaction catalysts are heteroatoms on the fiber surface. Molecular oxygen present in atmospheric air is the oxidant of the reaction. The method is environmentally friendly, simple, and economical route to produce a conductive form of PAni on carbon fiber. The composite produced was evaluated as a possible electrode for a supercapacitor, and presented interesting results for application in energy storage devices.

Electropolymerized Aniline-Based Stainless Steel Fiber Coatings Modified by Multi-Walled Carbon Nanotubes for Electroanalysis of 4-Chlorophenol.

In this paper, a stainless steel fiber coated electropolymerized aniline, without and with carbon nanotubes (SS/PANI and SS/PANI/CNT), along with CNTs modified carbon paste electrodes (CPEs), were prepared. The electrodes were characterized by differential pulse voltammetry (DPV) and applied for the detection of 4-chlorophenol (4-CP). For all the electrodes, the oxidative peak current showed a linear dependence on the 4-CP concentration in the range of 0.05–0.5 mmol/L with R2 ≥ 0.991. SS/PANI/CNT electrodes showed greater sensitivity for the detection of the 4-CP than the SS/PANI and CPEs. For all of the aniline-based stainless steel electrodes, both the LOD and LOQ decreased with the increase in the number of electropolymerization cycles. The lowest LOD (0.38 µmol/L) and LOQ (1.26 µmol/L) were observed for the SS/PANI/CNT electrode modified in aniline solution during 30 cycles. The methods were successfully applied to the analysis of 4-CP in real samples (tap water and river water). The results demonstrated the good agreement of the added and found concentrations of the 4-CP. The recovery and precision were from 95.12% to 102.24% and from 1.53% to 6.79%, respectively. The proposed electrodes exhibited acceptable reproducibility, admirable stability, and adequate repeatability and showed potential for the analysis of 4-CP in water.

Study of Different Acid Doped Polyaniline Nanostructures and Their Electrical Conductance Properties

The different acid doped polyaniline (PANI) materials were prepared in situ using mineral acids like HCl, H2SO4, HNO3 and HClO4 of different concentrations in presence of 0.2 M aniline solution and 0.25 M ammonium persulfate as oxidising agent by the chemical oxidation method. The synthesized materials were studied for their physico-chemical characterizations like XRD, IR and SEM. IR studies revealed the formation of emeraldine salt in all the acid doped PANI samples. XRD of samples exhibited the partly crystalline structure of which HClO4 doped showed good crystallinity over other samples. SEM images displayed the formation of nanorods like structural agglomerates. The effect of acid dopants on their electrical conductivity was investigated by using the four probe set up technique. It was found that HClO4 doped PANI exhibited good electrical conductivity over the other acid doped samples whereas the lowest electrical conductivity was recorded for HNO3 doped PANI samples. The electrical conductivity of 1 M HClO4 doped PANI was the highest i.e. 9.1 S cm-1 among all PANI samples.

Film-based fluorescent sensor for visual monitoring and efficient removal of aniline in solutions and gas phase

Aniline has attracted much concern for its long degradation half-life and huge toxicity to the environment and human beings. Therefore, the development of a multi-functional device for visual detection and efficient removal of aniline was highly anticipated. In our work, the small-size Eu@UiO-66(COOH) was obtained by post-synthesis modification (PSM), and then the film-based fluorescent sensor was prepared by crosslinking reaction. The films not only showed incredible mechanical stability and potential for large-scale preparation, but also have excellent fluorescence response to aniline in solutions and gas phase. As the concentration of aniline increased, the fluorescence of films gradually increased at 350 nm, while the fluorescence gradually quenching at 620 nm, and the detection limits (LOD) of aniline in water and air were 0.27 ppb and 0.086 ppb, respectively. In addition, the adsorption performance of the film for aniline has also been confirmed and the maximum adsorption capacity was 32.6 mg/g, which is a strong guarantee for the realization of ultra-trace detection and toxicity reduction of aniline. In summary, the multi-functional film sensor has been designed for ultra-trace detection and efficient removal of aniline in solutions and gas phase, and have significant value for pollutant treatment, ecological restoration and early prevention.