Facile preparation of UiO-66 /PAM monoliths via CO2-in-water HIPEs and their applications

A novel clean method to synthesis a composite monolith was developed. Given its amphiphilic property, UiO-66 can emulsify water and CO₂ to format a high internal phase emulsion (HIPE) under certain conditions. These UiO-66-emulsified Pickering HIPEs can be used as templates to prepare interconnected macroporous MOF/polymer composite monoliths. The effects of UiO-66 amount, cross-linking agent concentration, and CO₂–water ratio on UiO-66/PAM structures were investigated. Then, the as-synthesized MOF/PAM composites were characterized by TGA, XRD, SEM, and FT-IR analyses, as well as rheological and DMA measurements. The results indicated that the composites are interconnected with hierarchical pores, and the diameter of the voids is 10–50 μm. The directly prepared monoliths exhibited relatively high stresses at 82% strain and recovered their shape quickly. The adsorption capacity of the composites for methylene blue (MB) is 50 mg g⁻¹ at a faster adsorption rate. The monoliths also exhibit underlying applications in edible oil–water separation.

A novel UiO-66/PAM composite monolith with high performance was synthesized through a HIPE template.     

Shape engineering of polystyrene particles from spherical to raspberry-like to hollow flower-like via one-step non-surfactant self-templating polymerization of styrene in ethanol–water mixtures

We report a facile method for preparation of polystyrene (PS) particles with spherical, raspberry-like, and hollow flower-like structures by single-step non-surfactant self-templating polymerization of styrene in ethanol–water mixtures. PS particles with diverse morphologies could be easily obtained by simply adjusting the volume ratios of the styrene/water/ethanol mixture and initiator-ethanol–water mixture. By decreasing this ratio, the particles with spherical, raspberry-like, and hollow flower-like structures were obtained in sequence. The wettability of the coatings changing from hydrophilicity to hydrophobicity was easily tuned by the PS particles with different roughnesses. A competitive mechanism of interfacial polymerization and exudation was proposed to interpret the formation of PS particles with diverse morphologies.

We report a facile method for preparation of polystyrene (PS) particles with spherical, raspberry-like, and hollow flower-like structures by single-step non-surfactant self-templating polymerization of styrene in ethanol–water mixtures.     

Correction: Graphene material preparation through thermal treatment of graphite oxide electrochemically synthesized in aqueous sulfuric acid

Correction for ‘Graphene material preparation through thermal treatment of graphite oxide electrochemically synthesized in aqueous sulfuric acid’ by B. Gurzęda et al., RSC Adv., 2017, 7, 19904–19911.

The authors regret that the incorrect project number as financial support was included in the original article. The correct project number is 2015/17/B/ST8/00371.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Optical properties and photoactivity of carbon nanodots synthesized from olive solid wastes at different carbonization temperatures

Correction for ‘Optical properties and photoactivity of carbon nanodots synthesized from olive solid wastes at different carbonization temperatures’ by Shadi Sawalha et al., RSC Adv., 2022, 12, 4490–4500, https://doi.org/10.1039/D1RA09273A.

The authors regret that the name of one of the authors (Ahed Zyoud) was shown incorrectly in the original article. The corrected author list is as shown above.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Synthesis of nanoscale CuO via precursor method and its application in the catalytic epoxidation of styrene

Nanoscale CuO with diameters in the range of 7–8 nm has been synthesized via a two-step precipitation–calcination method using copper(ii) isonicotinate tetrahydrate as the precursor. The first step involves the room temperature stirring of an alkaline ethanolic solution of the precursor which gives a non-crystalline CuO species, while the second step involves the calcination of the product of the first step at 180 °C to form nanocrystalline CuO which has been characterized by PXRD, TEM, SEM, H₂-TPR and Raman spectroscopy, etc. The CuO material has shown excellent catalytic activity in the oxidation of styrene using TBHP as the oxidizing agent leading to complete styrene conversion with more than 95% styrene oxide selectivity at the end of 6 h. The oxide catalyst can be reused for at least 6 successive runs without significant loss in activity.

Nanoscale CuO with diameters in the range of 7–8 nm has been synthesized via a two-step precipitation–calcination method using copper(ii) isonicotinate tetrahydrate as the precursor.     

Molybdenum-doped iron oxide nanostructures synthesized via a chemical co-precipitation route for efficient dye degradation and antimicrobial performance: in silico molecular docking studies

In this research, various concentrations of molybdenum (2, 4 and 6 wt%) doped Fe₃O₄ nanostructures (Mo-Fe₃O₄ NSs) were prepared via a co-precipitation technique. Various techniques were then used to investigate the optical, morphological and structural properties of the NSs in the presence of the dopant materials. X-ray diffraction (XRD) was used to investigate the crystalline nature of the prepared NSs and confirm the orthorhombic and tetragonal structure of Fe₃O₄, with a decrease in crystallinity and crystallite sizes of 36.11, 38.45, 25.74 and 24.38 nm with increasing concentration of Mo (2, 4 and 6%). Fourier-transform infrared (FTIR) spectroscopy analysis was carried out to examine the functional groups in the NSs. Structure, surface morphology and topography were examined via field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM), which confirmed the fabrication of nanoparticles and nanorods and a floccule-like morphology with a higher doping concentration and the interlayer d-spacing was calculated using high-resolution (HR)TEM, the results of which were a good match to the XRD data. The presence of Mo, Fe and O in a lattice of Mo (2, 4 and 6%) doped Fe₃O₄ was confirmed by energy dispersive X-ray spectroscopy (EDS) analysis. The energy band gap (E_g) was measured via the optical analysis of pure and doped samples, showing a decrease from 2.76 to 2.64 eV. The photoluminescence (PL) spectra exhibit a higher charge combination rate of electron–hole pairs with a higher concentration of doping. The NSs exhibited excellent catalytic activity (CA) in degrading methylene blue (MB) dye in a basic medium by around 86.25%. Additionally, the antimicrobial activity was tested against Escherichia coli (E. coli) bacteria. Pairs of electrons and holes are the fundamental basis for generating reactive oxygen species that kill bacteria. The significant inhibition zones were calculated against E. coli bacteria at around 3.45 mm compared to ciprofloxacin. In silico docking investigations of the Mo-Fe₃O₄ NSs for dihydropteroate synthase (DHPS, binding score: 6.16 kcal mol⁻¹), dihydrofolate reductase (DHFR, binding score: 6.01 kcal mol⁻¹), and β-ketoacyl-acyl carrier protein synthase III (FabH, binding score: 5.75 kcal mol⁻¹) of E. coli show the suppression of the aforementioned enzymes as a potential mechanism besides their microbicidal assay.

In this research, various concentrations of molybdenum (2, 4 and 6 wt%) doped Fe₃O₄ nanostructures (Mo-Fe₃O₄ NSs) were prepared via a co-precipitation technique.     

Study on the degradation mechanism and pathway of benzene dye intermediate 4-methoxy-2-nitroaniline via multiple methods in Fenton oxidation process

Benzene dye intermediate (BDI) 4-methoxy-2-nitroaniline (4M2NA) wastewater has caused significant environmental concern due to its strong toxicity and potential carcinogenic effects. Reports concerning the degradation of 4M2NA by advanced oxidation process are limited. In this study, 4M2NA degradation by Fenton oxidation has been studied to obtain more insights into the reaction mechanism involved in the oxidation of 4M2NA. Results showed that when the 4M2NA (100 mg L⁻¹) was completely decomposed, the TOC removal efficiency was only 30.70–31.54%, suggesting that some by-products highly recalcitrant to the Fenton oxidation were produced. UV-Vis spectra analysis based on Gauss peak fitting, HPLC analysis combined with two-dimensional correlation spectroscopy and GC-MS detection were carried out to clarify the degradation mechanism and pathway of 4M2NA. A total of nineteen reaction intermediates were identified and two possible degradation pathways were illustrated. Theoretical TOC calculated based on the concentration of oxalic acid, acetic acid, formic acid, and 4M2NA in the degradation process was nearly 94.41–97.11% of the measured TOC, indicating that the oxalic acid, acetic acid and formic acid were the main products. Finally, the predominant degradation pathway was proposed. These results could provide significant information to better understand the degradation mechanism of 4M2NA.

Benzene dye intermediate (BDI) 4-methoxy-2-nitroaniline (4M2NA) wastewater has caused significant environmental concern due to its strong toxicity and potential carcinogenic effects.     

Correction: Patchouli oil isolated from the leaves of Pogostemon cablin ameliorates ethanol-induced acute liver injury in rats via inhibition of oxidative stress and lipid accumulation

Correction for ‘Patchouli oil isolated from the leaves of Pogostemon cablin ameliorates ethanol-induced acute liver injury in rats via inhibition of oxidative stress and lipid accumulation’ by Qiong-Hui Huang et al., RSC Adv., 2018, 8, 24399–24410.

The authors regret that

Comparison of Fe2TiO5/C photocatalysts synthesized via a nonhydrolytic sol–gel method and solid-state reaction method

Fe₂TiO₅/C photocatalysts were synthesized by a solid-state reaction method (Fe₂TiO₅/C_(S)) and nonhydrolytic sol–gel (NHSG) method (Fe₂TiO₅/C_(N)), where C was introduced by external carbon and in situ carbon sources, respectively. The Fe₂TiO₅/C_(N) photocatalyst with in situ carbon has much better photocatalytic degradation efficiency than that of Fe₂TiO₅/C_(S) synthesized by doping external carbon. The superiorities of in situ carbon were demonstrated by SEM, EDS, BET and photoelectrochemical analysis. Compared with Fe₂TiO₅/C_(S) using external carbon as a carbon source, Fe₂TiO₅/C_(N) with in situ carbon exhibits more uniform elemental distribution, much larger surface area, higher photocurrent density and lower resistivity of interfacial charge transfer. The results show that the introduction of in situ carbon via the NHSG method more easily promotes the separation of photogenerated electron–hole pairs, owing to the uniformity of the carbon element, thereby improving the photocatalytic activity of the photocatalyst.

Two different methods were used to prepare Fe₂TiO₅/C photocatalysts, demonstrating the superiorities of in situ carbon introduced by a NHSG method.     

Correction: Roles of water in the formation and preparation of graphene oxide

Correction for ‘Roles of water in the formation and preparation of graphene oxide’ by Qiang Zhang et al., RSC Adv., 2021, 11, 15808–15816, DOI: 10.1039/D0RA10026A.

The authors regret that there was an error in the author affiliations in the original article. The correct affiliations are given here.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

A Case of Ventricular Undersensing in the DDI Mode: Cause and Correction

A case is presented that demonstrates a confusing problem of ventricular undersensing in the DDI pacing mode. Electrocardiographic monitoring of the patient after pacemaker implantation revealed intermittent ventricular channel outputs which appeared to be inappropriate. These occurred a period of time after the intrinsic R wave, equal to the programmed AV interval. This problem was caused by ventricular lead undersensing, which resulted when the patient's intrinsic rate was such that the intrinsic ventricular complex occurred during the ventricular blanking period. The problem was corrected by reprogramming the blanking period.     

Rabbit pulmonary cytochrome P-450 monooxygenase system: isozyme differences in the rate and stereoselectivity of styrene oxidation

The rate and stereoselectivity of the cytochrome P-450 (P-450)-dependent oxidation of styrene to styrene 7,8-oxide (SO) were determined in rabbit pulmonary microsomes and with purified rabbit pulmonary P-450 isozymes in reconstituted monooxygenase systems. Stereoselectivity was determined by separation of the diastereomeric SO-glutathione adducts by high-performance liquid chromatography; these four compounds accounted for more than 95% of the SO formed. Pulmonary microsomes preferentially formed (R)-SO [(R)-SO/(S)-SO = 1.6] at a rate of 7.5 nmol of SO formed/min/nmol of P-450. Antibodies to NADPH-P-450 reductase (antireductase) inhibited SO formation in pulmonary microsomes by greater than 98%. In the presence of antibodies to P-450 form 2 (anti-2), pulmonary microsomes oxidized styrene to equal amounts of (R)- and (S)-SO at a rate of 4.2 nmol of SO/min/nmol of total P-450; in the presence of antibodies to P-450 form 5 (anti-5), styrene was stereoselectively oxidized to (R)-SO [(R)-SO/(S)-SO = 2.0] at a rate of 6.5 nmol of SO/min/nmol of total P-450. In reconstituted monooxygenase systems, P-450 forms 2, 5 and 6 oxidized styrene to SO at rates of 10.0, 4.7 and 4.5 nmol of SO formed/min/nmol of P-450, respectively. The relative amounts of (R)-SO and (S)-SO produced were 2.0, 1.0 and 0.9, respectively. Predicted values for rate and stereoselectivity of styrene oxidation by pulmonary microsomes, calculated from the values obtained in the reconstitution experiments and the relative concentrations of the different P-450 isozymes, agreed well with experimentally determined values.     

Experimental and theoretical investigation of intramolecular cooperativity in cyclic benzene trimer motif

A series of new symmetrical tripodal molecules 1a–4b with a central benzene scaffold substituted with methyl/ethyl groups and three benzimidazolyl units having a bithiophene/biphenyl/5-alkylthiophene motif at the 2-position via a –CH₂– unit were synthesized and characterized by elemental analysis, HR-MS, and NMR spectroscopy. NMR spectral data reveal that all molecules adopt a cyclic benzene trimer (CBT) using three benzimidazolyl units. Intramolecular cooperative edge-to-face C–H⋯π interactions stabilize the CBT motif in solution and are strong in ethyl substituted molecules (1b–4b) compared to methyl substituted (1a–4a) ones. However, the strength of the CBT unit in the tripodal molecule is independent of the length of the substituent at the 2-position of the benzimidazolyl unit. The relative ¹H NMR chemical shift calculated at the MPW1PW91/6-311+G(d,p) level of theory corroborates the experimental values, and the calculations predict the distribution of the structures into syn isomers. The relative change in the NMR chemical shift is justified by the relative change in the magnitude of the (3,+3) critical point (CP) in the molecular electrostatic potential (MESP) topography. Also, a linear correlation of the intramolecular C–H⋯π interactions evaluated at M062X/6-311+G(d,p) with the relative NMR chemical shift suggest the latter as a measure of intramolecular cooperativity.

A family of biaryl/alkylthiophene (R–R) benzimidazolyl-based tripodal molecules with cyclic benzene trimer (CBT) motif was synthesized and studied by NMR spectroscopy and MPW1PW91/6-311+G(d,p) theory.     

One-pot synthesis for gradient copolymers via concurrent tandem living radical polymerization: mild and selective transesterification of methyl acrylate through Al(acac)3 with common alcohols

A series of gradient copolymers were synthesized by the ruthenium-catalyzed living radical polymerization (LRP) of methyl acrylate (MA) and aliphatic alcohols using aluminum acetylacetonate Al(acac)₃. In this polymerization system, Al(acac)₃ was successfully used not only as an additive for the Ru-catalyzed LRP but also as a catalyst for the selective transesterification of an unsaturated ester monomer in mild conditions in a process known as concurrent tandem living radical polymerization. The resulting MA-based gradient copolymers showed well-controlled molecular weight and distribution in a one-pot reaction and exhibited a well-controlled gradient sequence in their polymer chain. Control of transesterification and the metal-catalyzed living radical polymerization (Mt-LRP) rate varied depending on the concentration of the Al(acac)₃ and the structure of varying alcohols, which were confirmed by ¹H NMR, SEC, and DSC analysis. In particular, this research opens a new synthetic methodology for preparing acrylate-based gradient copolymers via concurrent tandem LRP not limited to the synthesis of methyl methacrylate types of gradient copolymers.

The acrylate based gradient copolymers were successfully synthesized by concurrent tandem living radical polymerization using Al(acac)₃ as cocatalyst with common alcohols.     

Pacemaker Follow-Up: Its Role in the Detection and Correction of Pacemaker System Malfunction

The goal of pacemaker follow-up is not only to detect battery depletion but also to detect all malfunctions of the pacing system and, when possible, to correct such problems using programming. During one year, we discovered 61 such malfunctions in a clinic of 1065 patients (5.7%). These were more frequent in the first year (7.7%) than in the third to fifth years of follow-up (range 3.1-4.8%). The incidence rose again in the sixth and subsequent years (7-7.7%). Despite a significant occurrence of malfunctions (5.2%) among multiprogrammable pacemakers, the necessity for operative intervention for their correction was low (1.2%). Sensing problems were the most common (57%) and the most likely to be corrected by reprogramming (85%); problems involving loss of capture were less likely to be corrected by programming (38.5%). Battery depletion accounted for only 18% of malfunctions, occurring earliest in the forty-third month of follow-up. Pulse generator longevity of those devices reaching end of battery life during the study period was 68.6 +/- 16.7 months (mean + SD). We conclude that specialized pacemaker follow-up continues to be necessary despite improved pulse generator reliability and longevity. Indeed, with reprogramming, it presently plays an even more important role than in the past. Follow-up should be oriented not only to the detection of battery depletion but also toward a comprehensive surveillance of pacemaker system function.     

Correction: Individual control of singlet lifetime and triplet yield in halogen-substituted coumarin derivatives

Correction for ‘Individual control of singlet lifetime and triplet yield in halogen-substituted coumarin derivatives’ by Katrin E. Oberhofer et al., RSC Adv., 2020, 10, 27096–27102, DOI: 10.1039/D0RA05737A.

The authors regret that the name of one of the authors (Petko St. Petkov) was shown incorrectly in the original article. The corrected author list is as shown above.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Corrosion and tribocorrosion performance of multilayer diamond-like carbon film in NaCl solution

Correction for ‘Corrosion and tribocorrosion performance of multilayer diamond-like carbon film in NaCl solution’ by Mingjun Cui et al., RSC Adv., 2015, 5, 104829–104840, DOI: 10.1039/C5RA21207C.

The authors regret that the scale bars for the SEM image in Fig. 3a and c were mislabelled. The correct scale bar should be 100 μm, and the corresponding SEM images are shown below.Fig. 3a SEM surface morphology for single layer DLC film.Fig. 3c SEM surface morphology for multilayer DLC film.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.