One-step Fabrication of Physical Eutectogel with Recyclability: Crystalline Domain Regulation Induced by Microgels.

HYPOTHESIS: Despite their non-volatility, low cost, and recyclability, physical eutectogels' appeal is hindered by the intricate fabrication process and the involvement of hazardous chemicals. The network of polyvinyl alcohol (PVA) in deep eutectic solvent (choline chloride and glycerol) might be developed by the addition of microgels of polyacrylic acid (Carbopol). EXPERIMENTS: Hydrogen-bond interactions between Carbopol and PVA are revealed through Fourier-transform infrared spectroscopy. The impact of microgels on crystalline domains and the polymer network can be observed using X-ray diffraction and scanning electron microscopy. The physical properties of the eutectogel, including mechanical strength and ionic conductivity, are investigated as well. Finally, the strain-sensing ability and remarkable recyclability of the eutectogel are demonstrated. FINDINGS: The physical eutectogel can be obtained through a one-step fabrication process using only green and low-cost materials. It demonstrates robust strength (1.02 MPa) and remarkable stretchability (1000 % strain). This is attributed to the uniform dispersion of PVA crystalline domains within the deep eutectic solvent, facilitated by the hydrogen bonds and space restriction effects between PVA and Carbopol. Furthermore, the physical eutectogel with recyclability can consistently generate electrical resistance signals, highlighting its potential as a reliable strain sensor.

Adsorption and desorption of crystal violet and basic red 9 by multi-walled carbon nanotubes.

Batch adsorption and desorption of crystal violet (CV) and basic red 9 (BR9) on multi-walled carbon nanotubes (MWCNTs) were conducted. To investigate the possible mechanisms of adsorption/desorption hysteresis, oxidized MWCNTs (O-MWCNTs) with more oxygen-containing groups were obtained by oxidizing as-purchased MWCNTs (A-MWCNTs) using nitric acid. The adsorption kinetics could be described by the pseudo-second-order model, suggesting that chemical reactions are the rate-limiting steps. The adsorption isotherms were fitted well by the Langmuir model, which suggests that, in addition to π-π interactions, chemical reactions significantly affect the adsorption. The adsorption capacity decreased in the order of CV on A-MWCNTs, BR9 on A-MWCNTs, and BR9 on O-MWCNTs, possibly because the amidation between BR9 and the surface groups of MWCNTs results in steric hindrance, which limits the adsorption of BR9 to inner grooves between CNT bundles. Adsorption/desorption hysteresis was observed for BR9 but not for CV. It was found that the π-π interaction and molecular entrapment were not responsible for the adsorption/desorption hysteresis. The hysteresis might be caused by the irreversible amide bonds between BR9 and MWCNTs. The results indicate that the steric hindrance due to the three-dimensional structure of organic compounds plays an important role in both adsorption/desorption kinetics and equilibria.

Application of Escherichia coli antibiotic resistance patterns for contamination source identification in watershed.

Spatial correlation of pollution of the water resource in Taipei, Taiwan, were examined by analyzing the antibiotic resistance patterns (ARPs) of 96 Escherichia coli colonies, which were isolated from 7 sampling sites in 3 river sections. The ARPs were the growth patterns of isolated E. coli colonies in the medium with seven kinds of antibiotics, including ampicillin, chlortetracycline, erythromycin, oxytetracycline, streptomycin, tetracycline, and salinomycin of different concentrations. The results showed that the survival rate of E. coli decreased with increasing concentration of antibiotics; however, various ARPs under different antibiotics of different concentrations significantly increased both the useful information and complexities. Hierarchical cluster analysis (HCA) and two-stage principal component analysis (PCA) were applied to analyze the spatial correlations and interrelations of distinct ARPs among sampling sites in this study. It was found that the seven sampling sites can be categorized into three groups which may represent three possible pollution characteristics.

Enhanced electrochemical degradation of ibuprofen in aqueous solution by PtRu alloy catalyst.

Electrochemical advanced oxidation processes (EAOPs) regarded as a green technology for aqueous ibuprofen treatment was investigated in this study. Multi-walled carbon nanotubes (MWCNTs), Pt nanoparticles (Pt NPs), and PtRu alloy, of which physicochemical properties were characterized by XRD and X-ray absorption spectroscopy, were used to synthesize three types of cheap and effective anodes based on commercial conductive glass. Furthermore, the operating parameters, such as the current densities, initial concentrations, and solution pH were also investigated. The intermediates determined by a UPLC-Q-TOF/MS system were used to evaluate the possible reaction pathway of ibuprofen (IBU). The results revealed that the usage of MWCNTs and PtRu alloy can effectively reduce the grain size of electrocatalysts and increase the surface activity from the XRD and XANES analysis. The results of CV analysis, degradation and mineralization efficiencies revealed that the EAOPs with PtRu-FTO anode were very effective due to advantages of the higher capacitance, CO tolerance, catalytic ability at less positive voltage and stability. The concentration trend of intermediates indicated that the potential cytotoxic to human caused by 1-(1-hydroxyenthyl)-4-isobutylbenzene was completely eliminated as the reaction time reaches 60 min. Therefore, EAOPs combined with synthesized anodes can be feasibly applied on the electrochemical degradation of ibuprofen.

Effective anodic oxidation of naproxen by platinum nanoparticles coated FTO glass.

This study investigated applications of the electrochemical anodic oxidation process with Pt-FTO and Pt/MWCNTs-FTO glasses as anodes on the treatment of one of the most important emerging contaminants, naproxen. The anodes used in this study have been synthesized using commercial FTO, MWCNTs and Pt nanoparticles (PtNP). XRD patterns of Pt nanoparticles coated on FTO and MWCNTs revealed that MWCNTs can prevent the surface of PtNPs from sintering and thus provide a greater reaction sites density to interact with naproxen, which have also been confirmed by higher degradation and mineralization efficiencies in the Pt/MWCNTs-FTO system. Results from the CV analysis showed that the Pt-FTO and Pt/MWCNTs-FTO electrodes possessed dual functions of decreasing activation energy and interactions between hydroxyl radicals to effectively degrade naproxen. The lower the solution pH value, the better the degradation efficiency. The existence of humic acid indeed inhibited the degradation ability of naproxen due to the competitions in the multiple-component system. The electrochemical degradation processes were controlled by diffusion mechanism and two major intermediates of 2-acetyl-6-methoxynaphthalene and 2-(6-Hydroxy-2-naphthyl)propanoic acid were identified. This study has successfully demonstrated new, easy, flexible and effective anodic materials which can be feasibly applied to the electrochemical oxidation of naproxen.

Removal of nanoparticles from CMP wastewater by magnetic seeding aggregation.

CMP wastewaters have high solids content resulted from abrasive nanoparticles. Tremendous amount of ultrapure water consumption also makes the removal of nanoparticles from CMP wastewaters an important issue. Magnetic seeding aggregation of silica nanoparticles from the oxide CMP wastewater is studied in this work. Magnetite nanoparticles were synthesized and used as seeding particles. The turbidity of the CMP wastewater was reduced from 110 NTU to 7 NTU when solution pH was 6 and no addition of salt. This is because silica and magnetite nanoparticles were highly oppositely charged and the aggregation between silica and magnetite nanoparticles was achieved by electrostatic attractions. When the seeded wastewater was placed in a magnetic field strength higher than 800 G, the turbidity of the CMP wastewater was reduced to 1 NTU, which was clearer than the CMP wastewater treated by many other technologies.